#![forbid(unsafe_code)]

//! `FParkan` render-planning composition root.

use fparkan_animation::{AnimationTime, NodePoseBuffer};
use fparkan_assets::{
    load_material_archive_name_texture_rgba8_and_phase_with_document_from_root,
    load_material_name_texture_rgba8_and_phase_with_document_from_root,
    load_resource_entry_bytes_from_root,
    load_standalone_wear_named_material_textures_rgba8_and_phases_with_documents_from_root,
    page_uv_transform, sample_control_node_times, sample_material_normalized_phase,
    sample_material_phase, ControlInstanceState, ControlSamplingError, Mat0Document, MaterialPhase,
    MaterialPhaseSample, PreparedComponentControl, PreparedControlEffectRow,
    PreparedControlEffectSection, PreparedControlGateProvider, PreparedControlNodeBinding,
    PreparedControlPoint, PreparedControlPointList, PreparedMaterialPhase, PreparedModel,
    PreparedTexture, PreparedTextureUsage, PreparedVisual, RgbaImage, StandaloneWearMaterialLoader,
};
use fparkan_fx::ambient_op3::{
    evaluate_op3_type0_command, evaluate_op3_type1_command, evaluate_op3_type2_command,
};
use fparkan_fx::atmosphere::{AtmosphereFrame, TypedAtmosphere};
use fparkan_fx::environment::{
    decode_env_lightning_fxid, evaluate_op1_point_light_with_basis, Camera as FxCamera,
    EnvironmentFrame, EnvironmentPrimitive, EnvironmentSystem, PrecipitationKind, ScreenBillboard,
};
use fparkan_fx::fx_visual::{evaluate_f_gener_ball, evaluate_f_gener_ball_mesh};
use fparkan_fx::op7::{
    evaluate_op7_emitter, Op7EmitterState, Op7RenderContext, Op7VisibilityProfile,
};
use fparkan_fx::shadow::{
    ShadowCamera, ShadowCaster, ShadowFrame, ShadowLight, ShadowLodSettings, ShadowPageCache,
    ShadowScene, ShadowSphere, ShadowTriangle, SHADOW_PRIMARY_DIRECTIONAL_FLAG,
};
use fparkan_fx::sky::{
    sprite_half_size_pixels, SkyFrame, SkyMaterials, SkyMesh, SkyPassKind, SkySpriteFrame,
    SkySystem, SunVisibility, SKY_FLARE_ROWS,
};
use fparkan_fx::smoke::{evaluate_op8_emitter, Op8DetailThresholdRange, SmokeEmitterState};
use fparkan_fx::{advance_native_fx_random_state, decode_fxid, FxCommand, FxDocument, FxOpcode};
#[cfg(test)]
use fparkan_material::{MaterialAnimationBlock, MaterialKey};
use fparkan_msh::{
    node38_fallback_hierarchy, node38_sampled_hierarchy, node38_sampled_hierarchy_at_times,
    selected_slot, Group, Lod, ModelAsset, NodeId, SlotId,
};
use fparkan_path::ResourceName;
use fparkan_platform_winit::{window_native_handles, WinitWindow, WinitWindowPlan};
use fparkan_prototype::{unit_component_tree, PROTOTYPE_TYPE_EXTO};
use fparkan_render::{
    LegacyBlendMode, LegacyCullMode, LegacyD3d7Projection, LegacyDepthBias, LegacyDepthMode,
    LegacyIron3dEulerTransform, LegacyPipelineState, RawCameraTransform,
};
use fparkan_render_vulkan::{
    node38_pose, node38_pose_from_hierarchy, node38_pose_relative_to_root,
    node38_pose_relative_to_root_from_hierarchy, project_land_msh_to_static_mesh_in_world_space,
    project_msh_to_static_mesh_in_world_space_with_node_fallback_poses,
    project_msh_to_static_mesh_in_world_space_with_node_fallback_poses_and_mount,
    project_msh_to_static_mesh_in_world_space_with_node_pose_buffer,
    project_msh_to_static_mesh_in_world_space_with_node_pose_buffer_and_mount,
    project_msh_to_static_mesh_in_world_space_with_node_sampled_poses,
    project_msh_to_static_mesh_in_world_space_with_node_sampled_poses_and_mount,
    VulkanDynamicDrawRange, VulkanNodePose, VulkanPointLight, VulkanReadbackArtifact,
    VulkanSmokeFrameOutcome, VulkanSmokeRenderer, VulkanSmokeRendererCreateInfo,
    VulkanStaticCamera, VulkanStaticDrawRange, VulkanStaticMaterial, VulkanStaticMesh,
    VulkanStaticTexture, VulkanStaticTextureMip, VulkanStaticVertex,
};
use fparkan_runtime::{
    create, load_mission_static_preview, load_mission_static_preview_roots, loaded_mission_assets,
    loaded_mission_object_drafts, loaded_terrain, query_building_segment_world,
    BasementPlacementMode, BuildingMeshNode, EngineServices, MissionAssets, MissionMode,
    MissionObjectDraft, MissionRequest,
};
#[cfg(test)]
use fparkan_terrain::BasementFoundationFragment;
use fparkan_terrain::{
    build_basement_foundations, BasementFootprint, BasementFoundation, BasementPlacement,
    FullSurfaceMask, SurfaceQuery, TerrainLod, TerrainMaterialLayers, TerrainWorld,
};
use fparkan_vfs::DirectoryVfs;
use serde::Deserialize;
use std::collections::{HashMap, HashSet};
use std::io::Write;
use std::num::NonZeroUsize;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use std::time::{Duration, Instant};
use winit::application::ApplicationHandler;
use winit::dpi::PhysicalSize as WinitPhysicalSize;
use winit::event::{DeviceEvent, DeviceId, ElementState, MouseButton, WindowEvent};
use winit::event_loop::{ActiveEventLoop, ControlFlow, EventLoop};
use winit::keyboard::{KeyCode, PhysicalKey};
use winit::window::{CursorGrabMode, Window, WindowId};

mod audio;

fn main() {
    let raw_args = std::env::args().skip(1).collect::<Vec<_>>();
    let code = match run(&raw_args) {
        Ok(output) => {
            println!("{output}");
            0
        }
        Err(err) => {
            eprintln!("{err}");
            2
        }
    };
    std::process::exit(code);
}

fn run(args: &[String]) -> Result<String, String> {
    let args = Args::parse(args)?;
    let services = EngineServices::new(Arc::new(DirectoryVfs::new(&args.root)));
    let mut engine = create(services).map_err(|err| err.to_string())?;
    let mission_assets_started = Instant::now();
    let loaded = load_requested_mission(&mut engine, &args)?;
    let mission_assets_duration = mission_assets_started.elapsed();

    let mission_assets = loaded_mission_assets(&engine)
        .ok_or_else(|| "mission assets are unavailable after loading".to_string())?;
    let terrain = loaded_terrain(&engine)
        .ok_or_else(|| "mission terrain is unavailable after loading".to_string())?;
    let roots = loaded_mission_object_drafts(&engine)
        .map(|drafts| &drafts[..args.preview_roots.get().min(drafts.len())])
        .filter(|roots| !roots.is_empty())
        .ok_or_else(|| {
            "selected mission object drafts are unavailable after loading".to_string()
        })?;
    let camera = args
        .legacy_camera_capture
        .as_deref()
        .map(load_legacy_camera_capture)
        .transpose()?;
    let atmosphere_seconds = selected_atmosphere_seconds(args.atmosphere_seconds, camera.as_ref());
    let hold_schedule_phase = camera.is_some() && atmosphere_seconds.is_some();
    let terrain_materials_duration_started = Instant::now();
    let preview = static_preview_mesh_and_materials(
        mission_assets,
        terrain,
        roots,
        camera,
        args.static_animation_frame,
        args.static_material_phase,
        &args.root,
        &loaded.land_msh_path,
    )?;
    let terrain_materials_duration = terrain_materials_duration_started.elapsed();
    // Atmosphere files are mission-local assets.  Resolving them from the
    // entire install tree would silently attach the first unrelated mission's
    // sky to the selected map (there are many `sky.ske` files in the campaign
    // tree).
    let sky_started = Instant::now();
    let environment = load_environment(
        &args.root,
        &args.mission,
        atmosphere_seconds,
        hold_schedule_phase,
    )?;
    let sky_duration = sky_started.elapsed();
    let audio = match audio::GameAudio::new(Arc::new(DirectoryVfs::new(&args.root)), &args.mission)
    {
        Ok(audio) => Some(audio),
        Err(audio::AudioError::DeviceUnavailable { message }) => {
            eprintln!("audio output unavailable; continuing without sound: {message}");
            None
        }
        Err(error) => return Err(format!("load mission audio: {error}")),
    };
    run_static_vulkan_mode(
        preview,
        environment,
        audio,
        args.frames,
        &args.mission,
        loaded.object_count,
        args.readback_out.as_deref(),
        args.readback_sequence_out.as_deref(),
        args.validation,
        args.control_clock_ms,
        StartupTimings {
            mission_assets: mission_assets_duration,
            terrain_materials: terrain_materials_duration,
            sky: sky_duration,
            gpu_initialization: Duration::ZERO,
        },
    )
}

fn load_requested_mission(
    engine: &mut fparkan_runtime::Engine,
    args: &Args,
) -> Result<fparkan_runtime::LoadedMission, String> {
    let request = MissionRequest {
        key: args.mission.clone(),
        mode: MissionMode::SingleMission,
    };
    if args.preview_roots.get() == 1 {
        load_mission_static_preview(engine, request)
    } else {
        load_mission_static_preview_roots(engine, request, args.preview_roots)
    }
    .map_err(|err| err.to_string())
}

/// Camera state used by the interactive world-space preview.
#[derive(Clone, Copy, Debug, PartialEq)]
struct FreeFlightCamera {
    position: [f32; 3],
    yaw: f32,
    pitch: f32,
    horizontal_fov: f32,
    near_plane: f32,
    far_plane: f32,
    move_speed: f32,
    ground_clearance: f32,
}

impl FreeFlightCamera {
    fn from_mesh(mesh: &VulkanStaticMesh) -> Result<Self, String> {
        let mut min = [f32::INFINITY; 3];
        let mut max = [f32::NEG_INFINITY; 3];
        for vertex in &mesh.vertices {
            for axis in 0..3 {
                let value = vertex.position[axis];
                if !value.is_finite() {
                    return Err("world preview contains a non-finite vertex".to_string());
                }
                min[axis] = min[axis].min(value);
                max[axis] = max[axis].max(value);
            }
        }
        if !min.iter().chain(max.iter()).all(|value| value.is_finite()) {
            return Err("world preview has no finite bounds".to_string());
        }
        Self::from_bounds(min, max)
    }

    fn from_bounds(min: [f32; 3], max: [f32; 3]) -> Result<Self, String> {
        if !min.iter().chain(max.iter()).all(|value| value.is_finite()) {
            return Err("free-flight bounds must be finite".to_string());
        }
        let center = [
            (min[0] + max[0]) * 0.5,
            (min[1] + max[1]) * 0.5,
            (min[2] + max[2]) * 0.5,
        ];
        let radius = (0..3)
            .map(|axis| (max[axis] - min[axis]).abs())
            .fold(1.0_f32, f32::max);
        if !radius.is_finite() || radius <= f32::EPSILON {
            return Err("free-flight bounds are degenerate".to_string());
        }
        let position = [
            center[0],
            center[1] - radius * 2.5,
            center[2] + radius * 1.25,
        ];
        let direction = sub3(center, position);
        let distance = length3(direction)
            .ok_or_else(|| "free-flight initial camera has no direction to the map".to_string())?;
        let yaw = direction[1].atan2(direction[0]);
        let pitch = (direction[2] / distance).clamp(-1.0, 1.0).asin();
        Ok(Self {
            position,
            yaw,
            pitch,
            horizontal_fov: 1.3,
            near_plane: 0.5,
            far_plane: 700.0,
            // Keep the default traversal speed comfortable on a full mission
            // map; Shift/Ctrl still provide the coarse speed controls.
            move_speed: (radius * 0.03).clamp(4.0, 40.0),
            ground_clearance: 0.0,
        })
    }

    fn from_mesh_and_terrain(
        mesh: &VulkanStaticMesh,
        terrain: &TerrainWorld,
    ) -> Result<Self, String> {
        let mut camera = Self::from_mesh(mesh)?;
        let positions = terrain
            .source_positions()
            .ok_or_else(|| "free-flight terrain has no source positions".to_string())?;
        let mut min = [f32::INFINITY; 3];
        let mut max = [f32::NEG_INFINITY; 3];
        for position in positions {
            if !position.iter().all(|value| value.is_finite()) {
                return Err("free-flight terrain contains a non-finite position".to_string());
            }
            for axis in 0..3 {
                min[axis] = min[axis].min(position[axis]);
                max[axis] = max[axis].max(position[axis]);
            }
        }
        if !min.iter().chain(max.iter()).all(|value| value.is_finite()) {
            return Err("free-flight terrain has no finite bounds".to_string());
        }
        let extent = (max[0] - min[0]).max(max[1] - min[1]);
        if !extent.is_finite() || extent <= f32::EPSILON {
            return Err("free-flight terrain has degenerate XY bounds".to_string());
        }
        let center = [(min[0] + max[0]) * 0.5, (min[1] + max[1]) * 0.5];
        let offset = extent * 0.18;
        let requested_spawn = [
            (center[0] - offset).clamp(min[0], max[0]),
            (center[1] - offset).clamp(min[1], max[1]),
        ];
        let sample_offsets = [
            [0.0, 0.0],
            [0.18, 0.18],
            [-0.18, 0.18],
            [0.18, -0.18],
            [-0.18, -0.18],
            [0.0, 0.18],
            [0.18, 0.0],
            [-0.18, 0.0],
            [0.0, -0.18],
        ];
        let height_world = |xy: [f32; 2]| {
            terrain
                .height_at(xy)
                .ok()
                .flatten()
                .filter(|height| height.is_finite())
        };
        let (spawn_xy, spawn_ground) = sample_offsets
            .into_iter()
            .map(|sample| {
                [
                    (requested_spawn[0] + sample[0] * extent).clamp(min[0], max[0]),
                    (requested_spawn[1] + sample[1] * extent).clamp(min[1], max[1]),
                ]
            })
            .find_map(|xy| height_world(xy).map(|height| (xy, height)))
            .ok_or_else(|| "free-flight terrain has no queryable spawn surface".to_string())?;
        let target_ground = height_world(center).unwrap_or(spawn_ground);
        let clearance = (extent * 0.005).clamp(2.0, 8.0);
        camera.ground_clearance = clearance;
        camera.position = [spawn_xy[0], spawn_xy[1], spawn_ground + clearance];
        let target = [center[0], center[1], target_ground + 1.5];
        let direction = sub3(target, camera.position);
        let distance = length3(direction)
            .ok_or_else(|| "free-flight terrain spawn has no view direction".to_string())?;
        camera.yaw = direction[1].atan2(direction[0]);
        camera.pitch = (direction[2] / distance).clamp(-1.0, 1.0).asin();
        Ok(camera)
    }

    fn keep_above_terrain(&mut self, terrain: &TerrainWorld) -> Result<(), String> {
        if !self.ground_clearance.is_finite() || self.ground_clearance < 0.0 {
            return Err("free-flight ground clearance must be finite and nonnegative".to_string());
        }
        if let Some([min, max]) = terrain.surface_bounds() {
            for axis in 0..2 {
                self.position[axis] = self.position[axis].clamp(min[axis], max[axis]);
            }
        }
        let Some(ground_height) = terrain
            .height_at([self.position[0], self.position[1]])
            .map_err(|error| format!("free-flight terrain height query: {error}"))?
        else {
            return Ok(());
        };
        if !ground_height.is_finite() {
            return Err("free-flight terrain height is not finite".to_string());
        }
        let minimum_z = ground_height + self.ground_clearance;
        if !minimum_z.is_finite() {
            return Err("free-flight terrain floor is not finite".to_string());
        }
        self.position[2] = self.position[2].max(minimum_z);
        Ok(())
    }
    fn forward(self) -> [f32; 3] {
        let (sin_yaw, cos_yaw) = self.yaw.sin_cos();
        let (sin_pitch, cos_pitch) = self.pitch.sin_cos();
        [cos_pitch * cos_yaw, cos_pitch * sin_yaw, sin_pitch]
    }

    fn right(self) -> [f32; 3] {
        normalize3(cross3(self.forward(), [0.0, 0.0, 1.0])).unwrap_or([1.0, 0.0, 0.0])
    }

    fn up(self) -> [f32; 3] {
        normalize3(cross3(self.right(), self.forward())).unwrap_or([0.0, 0.0, 1.0])
    }

    fn vertical_fov(self, aspect: f32) -> f32 {
        let aspect = if aspect.is_finite() && aspect > f32::EPSILON {
            aspect
        } else {
            16.0 / 9.0
        };
        2.0 * ((self.horizontal_fov * 0.5).tan() / aspect).atan()
    }

    fn look_delta(&mut self, dx: f64, dy: f64) {
        const SENSITIVITY: f32 = 0.0025;
        let dx = dx as f32;
        let dy = dy as f32;
        if dx.is_finite() && dy.is_finite() {
            // Moving the mouse right turns the view to the right.
            self.yaw -= dx * SENSITIVITY;
            self.pitch = (self.pitch - dy * SENSITIVITY).clamp(-1.5, 1.5);
        }
    }

    fn advance(&mut self, keys: &HashSet<KeyCode>, seconds: f32) {
        if !seconds.is_finite() || seconds <= 0.0 {
            return;
        }
        let mut movement = [0.0; 3];
        let forward = self.forward();
        let right = self.right();
        if keys.contains(&KeyCode::KeyW) {
            add3_in_place(&mut movement, forward);
        }
        if keys.contains(&KeyCode::KeyS) {
            add3_in_place(&mut movement, scale3(forward, -1.0));
        }
        if keys.contains(&KeyCode::KeyD) {
            add3_in_place(&mut movement, right);
        }
        if keys.contains(&KeyCode::KeyA) {
            add3_in_place(&mut movement, scale3(right, -1.0));
        }
        if keys.contains(&KeyCode::KeyE) {
            add3_in_place(&mut movement, [0.0, 0.0, 1.0]);
        }
        if keys.contains(&KeyCode::KeyQ) {
            add3_in_place(&mut movement, [0.0, 0.0, -1.0]);
        }
        let Some(direction) = normalize3(movement) else {
            return;
        };
        let mut speed = self.move_speed;
        if keys.contains(&KeyCode::ShiftLeft) || keys.contains(&KeyCode::ShiftRight) {
            speed *= 4.0;
        }
        if keys.contains(&KeyCode::ControlLeft) || keys.contains(&KeyCode::ControlRight) {
            speed *= 0.25;
        }
        self.position = add3(self.position, scale3(direction, speed * seconds));
    }

    fn vulkan_camera(self, aspect: f32) -> VulkanStaticCamera {
        VulkanStaticCamera {
            clip_from_world: clip_from_world_for_view(
                self.position,
                self.forward(),
                self.right(),
                self.up(),
                self.vertical_fov(aspect),
                self.near_plane,
                self.far_plane,
                aspect,
            ),
        }
    }

    fn preview_frame(self, aspect: f32) -> PreviewCameraFrame {
        let camera = self.vulkan_camera(aspect);
        PreviewCameraFrame {
            position: self.position,
            forward: self.forward(),
            right: self.right(),
            up: self.up(),
            vertical_fov: self.vertical_fov(aspect),
            near_plane: self.near_plane,
            far_plane: self.far_plane,
            clip_from_world: camera.clip_from_world,
        }
    }
}

fn preview_aspect(aspect: f32) -> f32 {
    if aspect.is_finite() && aspect > f32::EPSILON {
        aspect
    } else {
        16.0 / 9.0
    }
}

fn clip_from_world_for_view(
    position: [f32; 3],
    forward: [f32; 3],
    right: [f32; 3],
    up: [f32; 3],
    vertical_fov: f32,
    near_plane: f32,
    far_plane: f32,
    aspect: f32,
) -> [f32; 16] {
    let aspect = preview_aspect(aspect);
    // VulkanStaticCamera carries row-major D3D-style data. GLSL interprets
    // those bytes as a column-major mat4, so shader multiplication is the
    // transpose of this row-vector transform: world * V * P. The camera
    // basis is right-handed with +Z-up world coordinates and +Z depth.
    let view = [
        right[0],
        up[0],
        forward[0],
        0.0,
        right[1],
        up[1],
        forward[1],
        0.0,
        right[2],
        up[2],
        forward[2],
        0.0,
        -dot3(right, position),
        -dot3(up, position),
        -dot3(forward, position),
        1.0,
    ];
    let focal = (vertical_fov * 0.5).tan().recip();
    let near_plane = near_plane.max(0.001);
    let far_plane = far_plane.max(near_plane + 0.001);
    let projection = [
        focal / aspect,
        0.0,
        0.0,
        0.0,
        0.0,
        -focal,
        0.0,
        0.0,
        0.0,
        0.0,
        far_plane / (far_plane - near_plane),
        1.0,
        0.0,
        0.0,
        -(near_plane * far_plane) / (far_plane - near_plane),
        0.0,
    ];
    multiply_row_major(view, projection)
}

/// Immutable view data shared by the environment renderers. The optional
/// `FreeFlightCamera` remains only the input controller; captured views keep
/// their original basis and clip transform, including roll.
#[derive(Clone, Copy, Debug, PartialEq)]
struct PreviewCameraFrame {
    position: [f32; 3],
    forward: [f32; 3],
    right: [f32; 3],
    up: [f32; 3],
    vertical_fov: f32,
    near_plane: f32,
    far_plane: f32,
    clip_from_world: [f32; 16],
}

impl PreviewCameraFrame {
    fn from_legacy_d3d7(
        transform: RawCameraTransform,
        projection: LegacyD3d7Projection,
    ) -> Option<Self> {
        let camera = VulkanStaticCamera::from_legacy_d3d7(transform, projection)?;
        let view = transform.try_direct3d7_view_row_major()?;
        let width = projection.viewport[2].checked_sub(projection.viewport[0])?;
        let height = projection.viewport[3].checked_sub(projection.viewport[1])?;
        if width <= 0 || height <= 0 {
            return None;
        }
        let aspect = width as f32 / height as f32;
        let vertical_fov = 2.0 * ((projection.field_of_view_radians * 0.5).tan() / aspect).atan();
        let frame = Self {
            position: transform.translation(),
            // The camera axes are the columns of Ngi32's D3D7 view matrix.
            // Keeping them directly preserves native roll and avoids
            // reconstructing an incomplete yaw/pitch camera.
            right: [view[0], view[4], view[8]],
            up: [view[1], view[5], view[9]],
            forward: [view[2], view[6], view[10]],
            vertical_fov,
            near_plane: projection.near_plane,
            far_plane: projection.far_plane,
            clip_from_world: camera.clip_from_world,
        };
        (frame.position.iter().all(|value| value.is_finite())
            && frame.forward.iter().all(|value| value.is_finite())
            && frame.right.iter().all(|value| value.is_finite())
            && frame.up.iter().all(|value| value.is_finite())
            && frame.vertical_fov.is_finite()
            && frame.vertical_fov > 0.0
            && frame.vertical_fov < std::f32::consts::PI)
            .then_some(frame)
    }

    fn vulkan_camera(self) -> VulkanStaticCamera {
        VulkanStaticCamera {
            clip_from_world: self.clip_from_world,
        }
    }

    fn with_aspect(self, previous_aspect: f32, aspect: f32) -> Self {
        let previous_aspect = preview_aspect(previous_aspect);
        let aspect = preview_aspect(aspect);
        let horizontal_half_fov_tangent = (self.vertical_fov * 0.5).tan() * previous_aspect;
        let vertical_fov = 2.0 * (horizontal_half_fov_tangent / aspect).atan();
        let clip_from_world = clip_from_world_for_view(
            self.position,
            self.forward,
            self.right,
            self.up,
            vertical_fov,
            self.near_plane,
            self.far_plane,
            aspect,
        );
        Self {
            vertical_fov,
            clip_from_world,
            ..self
        }
    }

    fn forward(self) -> [f32; 3] {
        self.forward
    }

    fn right(self) -> [f32; 3] {
        self.right
    }

    fn up(self) -> [f32; 3] {
        self.up
    }

    fn native_sky_heading(self) -> f32 {
        // Terrain+0x4F9C0 uses atan2(forward.x, forward.y); CSky+0x481C5 adds pi later.
        self.forward[0].atan2(self.forward[1])
    }
}

const ENVIRONMENT_SPRITE_ROWS: [usize; 2] = [3, 4];
const ENVIRONMENT_FLARE_SLOTS: usize = 12;
const ENVIRONMENT_PARTICLE_SLOTS: usize = 1_000;
// shortcut: Effect.dll derives this from projected sphere size and a render-context
// quality table. Category 0 supplies a highest-detail mesh until that exact
// world category is available; this does not reproduce native LOD selection.
const AMBIENT_EFFECT_NATIVE_CATEGORY: u8 = 0;

#[derive(Clone, Copy, Debug)]
struct EnvironmentGpuRange {
    range_index: usize,
    vertex_start: usize,
    vertex_capacity: usize,
    material_index: usize,
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
enum AmbientEffectKind {
    Op3Type0,
    Op3Type1,
    Op3Type2,
    GenerBall,
    SmokePool,
    Op7ParticlePool,
}

#[derive(Clone, Debug)]
struct AmbientEffectGpuSlot {
    kind: AmbientEffectKind,
    time_mode: u32,
    header_flags: u32,
    random_instance_key: ControlEffectInstanceKey,
    random_seed: u32,
    phase_jitter: f32,
    random_shift: [f32; 3],
    owner_object_index: usize,
    owner_component_index: usize,
    owner_node_index: usize,
    owner_component_is_mounted: bool,
    root_transform: LegacyIron3dEulerTransform,
    owner_scale: [f32; 3],
    mount_pose: Option<VulkanNodePose>,
    local_from_effect: [[f32; 4]; 4],
    control_source: String,
    control_table_index: usize,
    control_row_index: usize,
    control_point_indices: [u32; 3],
    control_point_owners: [i32; 3],
    command: FxCommand,
    command_index: usize,
    duration_seconds: f32,
    world_from_effect: [[f32; 4]; 4],
    range: EnvironmentGpuRange,
    additional_particle_ranges: Vec<EnvironmentGpuRange>,
    material_animation_index: usize,
    additional_particle_material_animation_indices: Vec<usize>,
    smoke_emitter_state: Option<SmokeEmitterState>,
    op7_emitter_state: Option<Op7EmitterState>,
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
struct AmbientEffectMeshPrimitive {
    vertex_start: usize,
    vertex_count: usize,
    index_start: usize,
    index_count: usize,
}

#[derive(Clone, Debug)]
struct ControlPointLightSlot {
    time_mode: u32,
    header_flags: u32,
    random_instance_key: ControlEffectInstanceKey,
    random_seed: u32,
    phase_jitter: f32,
    random_shift: [f32; 3],
    duration_seconds: f32,
    owner_object_index: usize,
    owner_component_index: usize,
    owner_node_index: usize,
    owner_component_is_mounted: bool,
    root_transform: LegacyIron3dEulerTransform,
    owner_scale: [f32; 3],
    mount_pose: Option<VulkanNodePose>,
    local_from_effect: [[f32; 4]; 4],
    world_from_effect: [[f32; 4]; 4],
    command_index: usize,
    command: FxCommand,
}

#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
struct ControlEffectInstanceKey {
    object_index: usize,
    component_index: usize,
    table_index: usize,
    row_index: usize,
}

#[derive(Clone, Copy, Debug, Default, PartialEq)]
struct ControlEffectRandomSample {
    phase_jitter: f32,
    accumulated_shift: [f32; 3],
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
enum SceneSampleId {
    Live(u64),
    Replay(u64),
}

#[derive(Clone, Copy, Debug, PartialEq)]
struct FrameClockSample {
    id: SceneSampleId,
    time_ms: u32,
    delta_seconds: f32,
}

#[derive(Clone, Debug)]
struct NativeFxRandom16 {
    state: u32,
}

impl NativeFxRandom16 {
    fn new(seed: u32) -> Self {
        Self {
            state: if seed == 0 { 0xA341_316C } else { seed },
        }
    }

    fn next_u16(&mut self) -> u16 {
        advance_native_fx_random_state(&mut self.state)
    }

    fn symmetric_sample(&mut self, amplitude: f32) -> f32 {
        (f32::from(self.next_u16()) / 65_536.0 - 0.5) * amplitude
    }
}

#[derive(Clone, Debug)]
struct ControlEffectRandomState {
    header_flags: u32,
    phase_jitter_amplitude: f32,
    random_shift_amplitude: [f32; 3],
    phase_and_z_rng: NativeFxRandom16,
    xy_rng: NativeFxRandom16,
    sample: ControlEffectRandomSample,
    last_update_id: Option<SceneSampleId>,
    last_update_clock_ms: Option<u32>,
}

impl ControlEffectRandomState {
    fn new(seed: u32, header_flags: u32, phase_jitter: f32, random_shift: [f32; 3]) -> Self {
        Self {
            header_flags,
            phase_jitter_amplitude: phase_jitter,
            random_shift_amplitude: random_shift,
            phase_and_z_rng: NativeFxRandom16::new(seed ^ 0xA511_E9B3),
            xy_rng: NativeFxRandom16::new(seed ^ 0x63D8_3595),
            sample: ControlEffectRandomSample::default(),
            last_update_id: None,
            last_update_clock_ms: None,
        }
    }

    fn advance(
        &mut self,
        sample_id: SceneSampleId,
        control_clock_ms: u32,
        initial_phase: f32,
    ) -> ControlEffectRandomSample {
        // Native updates consume process-global RNG streams. The preview uses
        // a deterministic per-Control-row stream; sibling slots share one
        // sample and cadence, but native cross-row RNG ordering remains open.
        if self.last_update_id == Some(sample_id) {
            return self.sample;
        }
        if self.header_flags & 1 != 0 && initial_phase != -1.0 {
            self.sample.phase_jitter = self
                .phase_and_z_rng
                .symmetric_sample(self.phase_jitter_amplitude);
        } else {
            self.sample.phase_jitter = 0.0;
        }
        if self.header_flags & 8 != 0 {
            let shift_z = self
                .phase_and_z_rng
                .symmetric_sample(self.random_shift_amplitude[2]);
            let shift_y = self.xy_rng.symmetric_sample(self.random_shift_amplitude[1]);
            let shift_x = self.xy_rng.symmetric_sample(self.random_shift_amplitude[0]);
            self.sample.accumulated_shift[0] += shift_x;
            self.sample.accumulated_shift[1] += shift_y;
            self.sample.accumulated_shift[2] += shift_z;
        }
        self.last_update_id = Some(sample_id);
        self.last_update_clock_ms = Some(control_clock_ms);
        self.sample
    }
}

#[derive(Clone, Debug)]
struct PreparedEffectMaterial {
    document: Mat0Document,
    phase_material_indices: Vec<usize>,
    phase_uv_transforms: Vec<[f32; 4]>,
    phase_native_flag_40: Vec<bool>,
    phase_directional_rgb: Vec<[f32; 3]>,
    phase_additive_rgb: Vec<[f32; 3]>,
    initial_pipeline_category: u8,
}

#[derive(Clone, Debug)]
struct EnvironmentMaterialAsset {
    texture: VulkanStaticTexture,
    phase: PreparedMaterialPhase,
    document: Mat0Document,
    phase_textures: Vec<VulkanStaticTexture>,
    phases: Vec<PreparedMaterialPhase>,
}

/// One source MAT0 document retained for frame-time sampling.  The renderer
/// receives the selected coefficients through its dynamic material state;
/// keeping this binding beside the prepared scene avoids rebuilding assets or
/// reopening archives on every redraw.
#[derive(Clone, Debug)]
struct MaterialPhaseBinding {
    document: Mat0Document,
    animation_block_index: usize,
    wear_row_start_ms: u32,
    random_state: u32,
    frozen_phase_index: Option<usize>,
    phase_uv_transforms: Vec<[f32; 4]>,
}

/// Texture phases for the material stages that do not select the draw
/// variant.  Terrain MAT0 rows are independent: Land1 base, Land2 detail,
/// Land1 overlay, and Land2 overlay-detail can each have their own animation
/// timeline.  Keeping these handles beside the binding lets the renderer
/// update the three descriptor images in place without materialising every
/// Cartesian product of phase indices.
#[derive(Clone, Debug)]
struct MaterialStageTextures {
    detail: Option<Vec<VulkanStaticTexture>>,
    overlay: Option<Vec<VulkanStaticTexture>>,
    overlay_detail: Option<Vec<VulkanStaticTexture>>,
    applied_material_phases: HashMap<usize, [usize; 3]>,
}

impl MaterialPhaseBinding {
    fn sample(
        &mut self,
        material_index: usize,
        clock_ms: u32,
    ) -> Result<MaterialPhaseSample, String> {
        if let Some(phase_index) = self.frozen_phase_index {
            let phase_index = phase_index.min(self.document.phases.len().saturating_sub(1));
            let phase = self.document.phases.get(phase_index).ok_or_else(|| {
                format!(
                    "sample MAT0 material {material_index} at clock {clock_ms}ms: no material phases"
                )
            })?;
            return Ok(MaterialPhaseSample {
                phase_index,
                coefficients: phase.coefficients(),
                texture_raw: phase.texture_raw,
            });
        }

        // GetPhase's random mode asks the CRT generator for one fresh value
        // per query.  Animated loop/ping-pong/clamp modes do not consume the
        // RNG and receive the sampler's ignored value.
        let block = self
            .document
            .animation_blocks
            .get(self.animation_block_index)
            .or_else(|| self.document.animation_blocks.first());
        let random_value = if block.is_some_and(|block| block.header_raw & 7 == 3) {
            self.random_state = self
                .random_state
                .wrapping_mul(214_013)
                .wrapping_add(2_531_011);
            (self.random_state >> 16) & 0x7fff
        } else {
            0
        };
        sample_material_phase(
            &self.document,
            self.animation_block_index,
            clock_ms,
            self.wear_row_start_ms,
            random_value,
        )
        .map_err(|error| {
            format!(
                "sample MAT0 material {} at clock {clock_ms}ms: {error}",
                material_index
            )
        })
    }

    fn sample_normalized(
        &self,
        material_index: usize,
        normalized_phase: f32,
    ) -> Result<MaterialPhaseSample, String> {
        sample_material_normalized_phase(
            &self.document,
            self.animation_block_index,
            normalized_phase,
        )
        .map_err(|error| {
            format!(
                "sample MAT0 material {material_index} at normalized phase {normalized_phase}: {error}"
            )
        })
    }

    fn page_uv_transform(&self, phase_index: usize) -> [f32; 4] {
        self.phase_uv_transforms
            .get(phase_index)
            .copied()
            .or_else(|| self.phase_uv_transforms.first().copied())
            .unwrap_or([0.0, 0.0, 1.0, 1.0])
    }

    fn checked_page_uv_transform(&self, phase_index: usize) -> Result<[f32; 4], String> {
        self.phase_uv_transforms
            .get(phase_index)
            .copied()
            .ok_or_else(|| {
                format!(
                    "MAT0 Page transform is missing phase {phase_index} of {}",
                    self.phase_uv_transforms.len()
                )
            })
    }
}

#[derive(Clone, Debug)]
struct MaterialVariantSet {
    phase_material_indices: Vec<usize>,
    range_indices: Vec<usize>,
    pipeline_category: u8,
}

#[derive(Clone, Debug)]
struct MaterialAnimationBinding {
    initial_phase_index: usize,
    normalized_phase_override: Option<f32>,
    ambient_fx_material_alpha: bool,
    variants: Vec<MaterialVariantSet>,
    base: MaterialPhaseBinding,
    detail: Option<MaterialPhaseBinding>,
    overlay: Option<MaterialPhaseBinding>,
    overlay_detail: Option<MaterialPhaseBinding>,
    stage_textures: Option<MaterialStageTextures>,
}

#[derive(Clone, Copy, Debug)]
struct ActiveMaterialState {
    material_index: usize,
    phase_index: usize,
    diffuse_alpha: f32,
    additive_rgb: [f32; 3],
}

fn ambient_effect_material_alpha(is_ambient_effect: bool, sampled_opacity: f32) -> f32 {
    if is_ambient_effect {
        1.0
    } else {
        sampled_opacity
    }
}

fn sample_material_animation_base(
    binding: &mut MaterialAnimationBinding,
    clock_ms: u32,
) -> Result<MaterialPhaseSample, String> {
    match binding.normalized_phase_override {
        Some(normalized_phase) => binding
            .base
            .sample_normalized(binding.initial_phase_index, normalized_phase),
        None => binding.base.sample(binding.initial_phase_index, clock_ms),
    }
}

#[derive(Clone, Copy, Debug, PartialEq)]
struct AmbientEffectGeometryUpdate {
    range_index: usize,
    index_count: u32,
    command_rgb: [f32; 3],
}

fn selected_material_phase(
    variant: &MaterialVariantSet,
    phase_index: usize,
    pipeline_category_for: impl FnOnce(usize) -> Option<u8>,
) -> Result<(usize, u8), String> {
    let material_index = selected_material_variant_index(variant, phase_index)
        .ok_or_else(|| "MAT0 material animation has no texture variant".to_string())?;
    let pipeline_category = pipeline_category_for(material_index).ok_or_else(|| {
        format!("MAT0 material animation selector {material_index} is out of bounds")
    })?;
    Ok((material_index, pipeline_category))
}

#[derive(Clone, Copy, Debug)]
struct MaterialRangeSelection {
    range_index: usize,
    material_index: usize,
    pipeline_category: u8,
}

#[derive(Clone, Copy, Debug)]
struct MaterialPropertiesUpdate {
    material_index: usize,
    diffuse_alpha: f32,
    overlay_alpha: f32,
    base_directional: [f32; 3],
    base_additive: [f32; 3],
    overlay_directional: Option<[f32; 3]>,
    overlay_additive: Option<[f32; 3]>,
    specular_rgb: [f32; 3],
    specular_power: u8,
    overlay_specular_rgb: Option<[f32; 3]>,
    overlay_power: Option<u8>,
    uv_transforms: [[f32; 4]; 4],
}

#[derive(Clone, Copy, Debug)]
struct MaterialStagePhaseUpdate {
    binding_index: usize,
    material_index: usize,
    phases: [usize; 3],
}

#[derive(Clone, Debug, Default)]
struct MaterialFrameUpdate {
    active_materials: HashMap<usize, ActiveMaterialState>,
    range_selections: Vec<MaterialRangeSelection>,
    properties: Vec<MaterialPropertiesUpdate>,
    stage_phases: Vec<MaterialStagePhaseUpdate>,
}

fn sample_material_animations(
    bindings: &mut [MaterialAnimationBinding],
    materials: &[VulkanStaticMaterial],
    clock_ms: u32,
) -> Result<MaterialFrameUpdate, String> {
    let mut update = MaterialFrameUpdate::default();
    for (binding_index, binding) in bindings.iter_mut().enumerate() {
        let base_sample = sample_material_animation_base(binding, clock_ms)?;
        let material_alpha = ambient_effect_material_alpha(
            binding.ambient_fx_material_alpha,
            base_sample.coefficients.opacity,
        );
        let detail_sample = binding
            .detail
            .as_mut()
            .map(|detail| detail.sample(binding.initial_phase_index, clock_ms))
            .transpose()?;
        let overlay_sample = binding
            .overlay
            .as_mut()
            .map(|overlay| overlay.sample(binding.initial_phase_index, clock_ms))
            .transpose()?;
        let overlay_detail_sample = binding
            .overlay_detail
            .as_mut()
            .map(|overlay_detail| overlay_detail.sample(binding.initial_phase_index, clock_ms))
            .transpose()?;
        let mut updated_materials = HashSet::new();
        for variant in &mut binding.variants {
            let (material_index, pipeline_category) =
                selected_material_phase(variant, base_sample.phase_index, |index| {
                    materials
                        .get(index)
                        .map(|material| material.pipeline_category)
                })?;
            for &range_index in &variant.range_indices {
                update.active_materials.insert(
                    range_index,
                    ActiveMaterialState {
                        material_index,
                        phase_index: base_sample.phase_index,
                        diffuse_alpha: material_alpha,
                        additive_rgb: base_sample.coefficients.additive_rgb,
                    },
                );
                update.range_selections.push(MaterialRangeSelection {
                    range_index,
                    material_index,
                    pipeline_category,
                });
            }
            variant.pipeline_category = pipeline_category;
            if !updated_materials.insert(material_index) {
                continue;
            }
            let material = materials.get(material_index).ok_or_else(|| {
                format!("MAT0 material animation selector {material_index} is out of bounds")
            })?;
            let base_coefficients = base_sample.coefficients;
            let overlay_coefficients = overlay_sample.map(|sample| sample.coefficients);
            let (base_directional, base_additive, overlay_directional, overlay_additive) =
                if material.lightmap_mode {
                    // Terrain mode 3 samples the lightmap in the secondary
                    // stage and uses the authored directional RGB as additive.
                    ([0.0; 3], base_coefficients.directional_rgb, None, None)
                } else {
                    (
                        base_coefficients.directional_rgb,
                        base_coefficients.additive_rgb,
                        overlay_coefficients.map(|coefficients| coefficients.directional_rgb),
                        overlay_coefficients.map(|coefficients| coefficients.additive_rgb),
                    )
                };

            if !material.lightmap_mode {
                if let Some(stage_textures) = binding.stage_textures.as_ref() {
                    let stage_phases = [
                        detail_sample.map_or(0, |sample| sample.phase_index),
                        overlay_sample.map_or(0, |sample| sample.phase_index),
                        overlay_detail_sample.map_or(0, |sample| sample.phase_index),
                    ];
                    if stage_textures
                        .applied_material_phases
                        .get(&material_index)
                        .copied()
                        != Some(stage_phases)
                    {
                        update.stage_phases.push(MaterialStagePhaseUpdate {
                            binding_index,
                            material_index,
                            phases: stage_phases,
                        });
                    }
                }
            }
            let overlay_uv = overlay_sample
                .map(|sample| {
                    binding
                        .overlay
                        .as_ref()
                        .map_or([0.0, 0.0, 1.0, 1.0], |overlay| {
                            overlay.page_uv_transform(sample.phase_index)
                        })
                })
                .or(material.overlay_uv_transform)
                .unwrap_or([0.0, 0.0, 1.0, 1.0]);
            let detail_uv = if material.lightmap_mode {
                material.detail_uv_transform
            } else {
                detail_sample
                    .map(|sample| {
                        binding
                            .detail
                            .as_ref()
                            .map_or(material.detail_uv_transform, |detail| {
                                detail.page_uv_transform(sample.phase_index)
                            })
                    })
                    .or(Some(material.detail_uv_transform))
                    .unwrap_or([0.0, 0.0, 1.0, 1.0])
            };
            let overlay_detail_uv = if material.lightmap_mode {
                material
                    .overlay_detail_uv_transform
                    .unwrap_or([0.0, 0.0, 1.0, 1.0])
            } else {
                overlay_detail_sample
                    .map(|sample| {
                        binding.overlay_detail.as_ref().map_or(
                            material
                                .overlay_detail_uv_transform
                                .unwrap_or([0.0, 0.0, 1.0, 1.0]),
                            |overlay_detail| overlay_detail.page_uv_transform(sample.phase_index),
                        )
                    })
                    .or(material.overlay_detail_uv_transform)
                    .unwrap_or([0.0, 0.0, 1.0, 1.0])
            };
            let base_uv = binding
                .base
                .checked_page_uv_transform(base_sample.phase_index)?;
            update.properties.push(MaterialPropertiesUpdate {
                material_index,
                diffuse_alpha: material_alpha.clamp(0.0, 1.0),
                overlay_alpha: overlay_coefficients
                    .map_or(0.0, |coefficients| coefficients.opacity.clamp(0.0, 1.0)),
                base_directional,
                base_additive,
                overlay_directional,
                overlay_additive,
                specular_rgb: base_coefficients.specular_rgb,
                specular_power: base_coefficients.power,
                overlay_specular_rgb: overlay_coefficients
                    .map(|coefficients| coefficients.specular_rgb),
                overlay_power: overlay_coefficients.map(|coefficients| coefficients.power),
                uv_transforms: [base_uv, detail_uv, overlay_uv, overlay_detail_uv],
            });
        }
    }
    Ok(update)
}

fn apply_material_frame_update(
    update: &MaterialFrameUpdate,
    bindings: &mut [MaterialAnimationBinding],
    renderer: &mut VulkanSmokeRenderer,
) -> Result<(), String> {
    for selection in &update.range_selections {
        renderer
            .set_draw_range_material(selection.range_index, selection.material_index)
            .map_err(|error| format!("update MAT0 material draw selector: {error}"))?;
        renderer
            .set_draw_range_material_category(selection.range_index, selection.pipeline_category)
            .map_err(|error| format!("update MAT0 material pipeline category: {error}"))?;
    }
    for properties in &update.properties {
        renderer
            .set_material_alphas(
                properties.material_index,
                properties.diffuse_alpha,
                properties.overlay_alpha,
            )
            .map_err(|error| format!("update MAT0 material alpha: {error}"))?;
        renderer
            .set_material_lighting_with_overlay(
                properties.material_index,
                properties.base_directional,
                properties.base_additive,
                properties.overlay_directional,
                properties.overlay_additive,
            )
            .map_err(|error| format!("update MAT0 material lighting: {error}"))?;
        renderer
            .set_material_specular(
                properties.material_index,
                properties.specular_rgb,
                properties.specular_power,
                properties.overlay_specular_rgb,
                properties.overlay_power,
            )
            .map_err(|error| format!("update MAT0 material specular: {error}"))?;
        renderer
            .set_material_uv_transforms(properties.material_index, properties.uv_transforms)
            .map_err(|error| format!("update MAT0 material Page transform: {error}"))?;
    }
    for stage_update in &update.stage_phases {
        let stage_textures = bindings
            .get_mut(stage_update.binding_index)
            .and_then(|binding| binding.stage_textures.as_mut())
            .ok_or_else(|| "MAT0 stage texture binding disappeared".to_string())?;
        if stage_textures
            .applied_material_phases
            .get(&stage_update.material_index)
            .copied()
            == Some(stage_update.phases)
        {
            continue;
        }
        let textures = [
            stage_textures
                .detail
                .as_ref()
                .and_then(|textures| textures.get(stage_update.phases[0])),
            stage_textures
                .overlay
                .as_ref()
                .and_then(|textures| textures.get(stage_update.phases[1])),
            stage_textures
                .overlay_detail
                .as_ref()
                .and_then(|textures| textures.get(stage_update.phases[2])),
        ];
        for (stage, texture) in textures.into_iter().enumerate() {
            if let Some(texture) = texture {
                renderer
                    .update_material_texture(stage_update.material_index, stage + 1, texture)
                    .map_err(|error| match stage {
                        0 => format!("update MAT0 detail texture: {error}"),
                        1 => format!("update MAT0 overlay texture: {error}"),
                        _ => format!("update MAT0 overlay detail texture: {error}"),
                    })?;
            }
        }
        stage_textures
            .applied_material_phases
            .insert(stage_update.material_index, stage_update.phases);
    }
    Ok(())
}

fn native_world_transparent(range: &VulkanStaticDrawRange, diffuse_alpha: f32) -> bool {
    diffuse_alpha < 1.0 || (range.batch_flags & 0x108) != 0
}

fn native_msh_diffuse_alpha_override(batch_flags: u16, type16_present: bool) -> Option<f32> {
    if type16_present || batch_flags & 0x0008 == 0 {
        return None;
    }
    (batch_flags & 0x0040 != 0 && batch_flags & 0x0010 == 0).then_some(0.0)
}

fn native_msh_handedness(transform: LegacyIron3dEulerTransform, scale: [f32; 3]) -> i8 {
    let Some(origin) = transform.try_transform_scaled_point([0.0; 3], scale) else {
        return 0;
    };
    let Some(x_axis) = transform
        .try_transform_scaled_point([1.0, 0.0, 0.0], scale)
        .map(|point| sub3(point, origin))
    else {
        return 0;
    };
    let Some(y_axis) = transform
        .try_transform_scaled_point([0.0, 1.0, 0.0], scale)
        .map(|point| sub3(point, origin))
    else {
        return 0;
    };
    let Some(z_axis) = transform
        .try_transform_scaled_point([0.0, 0.0, 1.0], scale)
        .map(|point| sub3(point, origin))
    else {
        return 0;
    };
    // Node and mount poses in the preview are unit-quaternion rotations, so
    // they have determinant +1 and preserve this exact object-transform sign.
    let determinant_sign = dot3(x_axis, cross3(y_axis, z_axis));
    if !determinant_sign.is_finite() || determinant_sign == 0.0 {
        0
    } else if determinant_sign < 0.0 {
        -1
    } else {
        1
    }
}

fn native_msh_cull_mode(batch_flags: u16, handedness: i8) -> LegacyCullMode {
    if batch_flags & 0x2 != 0 || batch_flags & 0x4000 != 0 || handedness == 0 {
        LegacyCullMode::Disabled
    } else if handedness > 0 {
        // The Y-negated projection maps native d > 0 faces to Vulkan's back
        // under the renderer's CLOCKWISE front-face convention.
        LegacyCullMode::FrontFace
    } else {
        LegacyCullMode::BackFace
    }
}

fn native_msh_first_triangle_visible(
    mesh: &VulkanStaticMesh,
    range: &VulkanStaticDrawRange,
    eye_world: [f32; 3],
    handedness: i8,
) -> bool {
    if range.batch_flags & 0x2 != 0 || range.batch_flags & 0x4000 == 0 {
        return true;
    }
    if handedness == 0 {
        return false;
    }
    let Some(indices) = usize::try_from(range.first_index)
        .ok()
        .and_then(|first| mesh.indices.get(first..first.checked_add(3)?))
    else {
        return false;
    };
    let Some(v0) = usize::try_from(indices[0])
        .ok()
        .and_then(|index| mesh.vertices.get(index))
    else {
        return false;
    };
    let Some(v1) = usize::try_from(indices[1])
        .ok()
        .and_then(|index| mesh.vertices.get(index))
    else {
        return false;
    };
    let Some(v2) = usize::try_from(indices[2])
        .ok()
        .and_then(|index| mesh.vertices.get(index))
    else {
        return false;
    };
    let [v0, v1, v2] = [v0.position, v1.position, v2.position];
    let face = cross3(sub3(v1, v0), sub3(v2, v0));
    let facing = dot3(sub3(eye_world, v0), face) * f32::from(handedness);
    facing.is_finite() && facing > 0.0
}

fn world_draw_range_index_count(
    mesh: &VulkanStaticMesh,
    range: &VulkanStaticDrawRange,
    original_index_count: u32,
    diffuse_alpha: f32,
    eye_world: [f32; 3],
    native_msh_handedness: Option<i8>,
) -> u32 {
    if !(diffuse_alpha > 0.0) {
        return 0;
    }
    if native_msh_handedness.is_some_and(|handedness| {
        !native_msh_first_triangle_visible(mesh, range, eye_world, handedness)
    }) {
        return 0;
    }
    original_index_count
}

fn configure_world_material_categories(
    mesh: &mut VulkanStaticMesh,
    materials: &[VulkanStaticMaterial],
    world_range_indices: &[usize],
) -> Result<(), String> {
    for &range_index in world_range_indices {
        let range = mesh
            .draw_ranges
            .get_mut(range_index)
            .ok_or_else(|| "world material range index is out of bounds".to_string())?;
        let material = materials
            .get(usize::from(range.material_index))
            .ok_or_else(|| {
                format!(
                    "world material selector {} is out of bounds",
                    range.material_index
                )
            })?;
        range.pipeline_state = range
            .pipeline_state
            .with_material_category(material.pipeline_category)
            .ok_or_else(|| {
                format!(
                    "world material selector {} has unsupported native pipeline category {}",
                    range.material_index, material.pipeline_category
                )
            })?;
    }
    Ok(())
}

fn register_material_range(
    bindings: &mut [MaterialAnimationBinding],
    material_index: usize,
    range_index: usize,
) {
    for binding in bindings {
        if let Some(variant) = binding.variants.iter_mut().find(|variant| {
            variant
                .phase_material_indices
                .get(binding.initial_phase_index)
                .copied()
                == Some(material_index)
        }) {
            variant.range_indices.push(range_index);
            return;
        }
    }
}

fn find_material_animation_variant(
    bindings: &[MaterialAnimationBinding],
    material_index: usize,
) -> Option<(usize, Vec<usize>)> {
    bindings
        .iter()
        .enumerate()
        .find_map(|(binding_index, binding)| {
            binding.variants.iter().find_map(|variant| {
                (variant
                    .phase_material_indices
                    .get(binding.initial_phase_index)
                    .copied()
                    == Some(material_index))
                .then(|| (binding_index, variant.phase_material_indices.clone()))
            })
        })
}

fn selected_material_variant_index(
    variant: &MaterialVariantSet,
    phase_index: usize,
) -> Option<usize> {
    variant.phase_material_indices.get(phase_index).copied()
}

fn remap_material_animation_ranges(
    bindings: &mut [MaterialAnimationBinding],
    remap: &[usize],
) -> Result<(), String> {
    for binding in bindings {
        for variant in &mut binding.variants {
            for range_index in &mut variant.range_indices {
                *range_index = *remap
                    .get(*range_index)
                    .ok_or_else(|| "MAT0 draw range remap is out of bounds".to_string())?;
            }
        }
    }
    Ok(())
}

fn phase_texture_name(phase: &MaterialPhase) -> Option<ResourceName> {
    let length = phase
        .texture_raw
        .iter()
        .position(|byte| *byte == 0)
        .unwrap_or(phase.texture_raw.len());
    (length != 0).then(|| ResourceName(phase.texture_raw[..length].to_vec()))
}

fn phase_uv_transforms_from_assets(
    document: &Mat0Document,
    assets: &MissionAssets,
) -> Vec<[f32; 4]> {
    document
        .phases
        .iter()
        .map(|phase| {
            phase_texture_name(phase)
                .and_then(|name| {
                    assets
                        .textures
                        .iter()
                        .find(|texture| {
                            texture.usage == PreparedTextureUsage::Diffuse
                                && texture.source.name == name
                        })
                        .and_then(|texture| {
                            page_uv_transform(
                                texture.texm.width(),
                                texture.texm.height(),
                                &texture.texm.page_rects(),
                                i8::from_ne_bytes([phase.parameters[17]]),
                            )
                            .ok()
                        })
                })
                .unwrap_or([0.0, 0.0, 1.0, 1.0])
        })
        .collect()
}

fn phase_uv_transforms_from_standalone(
    loader: &mut StandaloneWearMaterialLoader,
    wear_path: &Path,
    material_index: u16,
    document: &Mat0Document,
) -> Result<Vec<[f32; 4]>, String> {
    document
        .phases
        .iter()
        .enumerate()
        .map(|(phase_index, phase)| {
            if phase_texture_name(phase).is_none() {
                return Ok([0.0, 0.0, 1.0, 1.0]);
            }
            loader
                .load(
                    wear_path,
                    material_index,
                    u16::try_from(phase_index).unwrap_or(u16::MAX),
                )
                .map(|(_, prepared)| prepared.page_uv_transform)
        })
        .collect()
}

#[derive(Clone, Copy, Debug)]
struct EnvironmentSkyLayer {
    kind: SkyPassKind,
    stage: Option<usize>,
    secondary_stage: Option<usize>,
    material_index: usize,
    diffuse_alpha: f32,
    static_directional_rgb: [f32; 3],
    static_additive_rgb: [f32; 3],
    translation_z: f32,
    range: EnvironmentGpuRange,
}

#[derive(Clone, Copy, Debug)]
struct EnvironmentSpriteLayer {
    row: usize,
    material_index: usize,
    diffuse_alpha: f32,
    flare_index: Option<usize>,
    range: EnvironmentGpuRange,
}

/// Fixed-capacity GPU allocations for the CPU-owned sky and environment
/// output.  The Vulkan renderer only receives one shared vertex update and
/// smaller draw counts each frame; descriptor images and index allocations
/// stay stable while the camera and weather move.
#[derive(Clone, Debug)]
struct EnvironmentGpuScene {
    material_animations: Vec<MaterialAnimationBinding>,
    sky_layers: Vec<EnvironmentSkyLayer>,
    sprites: Vec<EnvironmentSpriteLayer>,
    rain: EnvironmentGpuRange,
    snow: EnvironmentGpuRange,
    lightning: EnvironmentGpuRange,
    lightning_material_index: usize,
}

fn world_pipeline_state(blend: LegacyBlendMode, depth: LegacyDepthMode) -> LegacyPipelineState {
    LegacyPipelineState {
        blend,
        depth,
        ..LegacyPipelineState::default()
    }
}

fn projected_shadow_pipeline_state() -> LegacyPipelineState {
    LegacyPipelineState {
        blend: LegacyBlendMode::SourceAlpha,
        depth: LegacyDepthMode::TestReadOnly,
        depth_bias: LegacyDepthBias::ProjectedDecal,
        ..LegacyPipelineState::default()
    }
}

fn environment_vertex(position: [f32; 3], color: [f32; 3], uv: [f32; 2]) -> VulkanStaticVertex {
    environment_vertex_with_alpha(position, color, 1.0, uv)
}

fn environment_vertex_with_alpha(
    position: [f32; 3],
    color: [f32; 3],
    alpha: f32,
    uv: [f32; 2],
) -> VulkanStaticVertex {
    environment_vertex_with_alpha_normal(position, color, alpha, uv, [0.0, 0.0, 1.0])
}

fn environment_vertex_with_alpha_normal(
    position: [f32; 3],
    color: [f32; 3],
    alpha: f32,
    uv: [f32; 2],
    normal: [f32; 3],
) -> VulkanStaticVertex {
    VulkanStaticVertex {
        position,
        color,
        normal,
        uv,
        detail_uv: [0.0, 0.0],
        overlay_alpha: alpha.clamp(0.0, 1.0),
    }
}

fn sky_normal(raw: [i8; 3]) -> [f32; 3] {
    // Ngi32's cloud-light decode uses the signed-byte scale 1/128 and keeps
    // the authored vector length. Renormalizing (or using 1/127) changes the
    // edge values and shifts the native cloud shading.
    [
        f32::from(raw[0]) / 128.0,
        f32::from(raw[1]) / 128.0,
        f32::from(raw[2]) / 128.0,
    ]
}

fn solid_environment_texture(rgba: [u8; 4]) -> VulkanStaticTexture {
    let mip = VulkanStaticTextureMip {
        width: 1,
        height: 1,
        rgba8: rgba.to_vec(),
    };
    VulkanStaticTexture {
        width: 1,
        height: 1,
        rgba8: mip.rgba8.clone(),
        mip_levels: vec![mip],
    }
}

fn vulkan_texture_from_rgba_mips(
    mips: Vec<RgbaImage>,
    label: &str,
) -> Result<VulkanStaticTexture, String> {
    let first = mips
        .first()
        .ok_or_else(|| format!("{label} has no mip zero"))?;
    Ok(VulkanStaticTexture {
        width: first.width,
        height: first.height,
        rgba8: first.rgba8.clone(),
        mip_levels: mips
            .into_iter()
            .map(|mip| VulkanStaticTextureMip {
                width: mip.width,
                height: mip.height,
                rgba8: mip.rgba8,
            })
            .collect(),
    })
}

fn append_environment_material(
    materials: &mut Vec<VulkanStaticMaterial>,
    material_names: &mut HashMap<String, usize>,
    material_assets: &HashMap<String, EnvironmentMaterialAsset>,
    material_animations: &mut Vec<MaterialAnimationBinding>,
    name: &str,
    fallback_row: usize,
) -> Result<usize, String> {
    if let Some(index) = material_names.get(name).copied() {
        return Ok(index);
    }
    let asset = material_assets.get(name).ok_or_else(|| {
        format!("environment material {name:?} is missing from resolved material.lib/MAT0 assets")
    })?;
    let phases = if asset.phases.is_empty() {
        vec![asset.phase]
    } else {
        asset.phases.clone()
    };
    let first_material_index = materials.len();
    let mut phase_material_indices = Vec::with_capacity(phases.len());
    for (phase_index, phase) in phases.iter().enumerate() {
        let index = materials.len();
        let material_index = u16::try_from(index).map_err(|_| {
            "environment exceeds the available 16-bit material selector space".to_string()
        })?;
        materials.push(VulkanStaticMaterial {
            material_index,
            pipeline_category: phase.pipeline_category,
            texture: asset
                .phase_textures
                .get(phase_index)
                .cloned()
                .unwrap_or_else(|| asset.texture.clone()),
            directional_rgb: phase.directional_rgb,
            additive_rgb: phase.additive_rgb,
            uv_transform: phase.page_uv_transform,
            detail_texture: Some(solid_environment_texture([128, 128, 128, 255])),
            overlay_texture: None,
            overlay_detail_texture: None,
            diffuse_alpha: phase.diffuse_alpha.clamp(0.0, 1.0),
            overlay_diffuse_alpha: None,
            overlay_directional_rgb: None,
            overlay_additive_rgb: None,
            specular_rgb: phase.specular_rgb,
            specular_power: phase.power,
            overlay_specular_rgb: None,
            overlay_specular_power: None,
            detail_uv_transform: [0.0, 0.0, 1.0, 1.0],
            overlay_uv_transform: None,
            overlay_detail_uv_transform: None,
            // Native cloud draws carry shade/fog flags.  The remaining sky rows
            // are unlit overlays; all rows still retain their decoded normals.
            unlit: fallback_row != 2,
            sky_nebula_stars: false,
            lightmap_mode: false,
            sky_far_depth: matches!(fallback_row, 0..=2),
            screen_tl: ENVIRONMENT_SPRITE_ROWS.contains(&fallback_row),
        });
        phase_material_indices.push(index);
    }
    let document = asset.document.clone();
    material_animations.push(MaterialAnimationBinding {
        initial_phase_index: 0,
        normalized_phase_override: None,
        ambient_fx_material_alpha: false,
        variants: vec![MaterialVariantSet {
            phase_material_indices,
            range_indices: Vec::new(),
            pipeline_category: phases[0].pipeline_category,
        }],
        base: MaterialPhaseBinding {
            document,
            animation_block_index: 0,
            wear_row_start_ms: 0,
            random_state: first_material_index as u32,
            frozen_phase_index: None,
            phase_uv_transforms: phases.iter().map(|phase| phase.page_uv_transform).collect(),
        },
        detail: None,
        overlay: None,
        overlay_detail: None,
        stage_textures: None,
    });
    material_names.insert(name.to_owned(), first_material_index);
    Ok(first_material_index)
}

fn prepare_effect_material(
    root: &Path,
    archive: &str,
    name: &str,
    materials: &mut Vec<VulkanStaticMaterial>,
    cache: &mut HashMap<String, PreparedEffectMaterial>,
) -> Result<PreparedEffectMaterial, String> {
    let key = format!("{archive}/{name}");
    if let Some(prepared) = cache.get(&key) {
        return Ok(prepared.clone());
    }
    let (first_mips, first_phase, document) =
        load_material_archive_name_texture_rgba8_and_phase_with_document_from_root(
            root, archive, name, 0,
        )
        .map_err(|error| format!("resolve FX MAT0 {key}: {error}"))?;
    if document.phases.is_empty() {
        return Err(format!("FX MAT0 {key} has no phases"));
    }

    let mut phase_material_indices = Vec::with_capacity(document.phases.len());
    let mut phase_uv_transforms = Vec::with_capacity(document.phases.len());
    let mut phase_native_flag_40 = Vec::with_capacity(document.phases.len());
    let mut phase_directional_rgb = Vec::with_capacity(document.phases.len());
    let mut phase_additive_rgb = Vec::with_capacity(document.phases.len());
    for phase_index in 0..document.phases.len() {
        let (mips, phase) = if phase_index == 0 {
            (first_mips.clone(), first_phase)
        } else {
            let phase_index_u16 = u16::try_from(phase_index)
                .map_err(|_| format!("FX MAT0 {key} phase index exceeds u16"))?;
            let (mips, phase, _document) =
                load_material_archive_name_texture_rgba8_and_phase_with_document_from_root(
                    root,
                    archive,
                    name,
                    phase_index_u16,
                )
                .map_err(|error| format!("resolve FX MAT0 {key} phase {phase_index}: {error}"))?;
            (mips, phase)
        };
        let texture = vulkan_texture_from_rgba_mips(mips, "FX material")?;
        let index = materials.len();
        let material_index = u16::try_from(index).map_err(|_| {
            "FX effects exceed the available 16-bit material selector space".to_string()
        })?;
        materials.push(VulkanStaticMaterial {
            material_index,
            pipeline_category: phase.pipeline_category,
            texture,
            directional_rgb: phase.directional_rgb,
            additive_rgb: phase.additive_rgb,
            uv_transform: phase.page_uv_transform,
            detail_texture: Some(solid_environment_texture([128, 128, 128, 255])),
            overlay_texture: None,
            overlay_detail_texture: None,
            // FX descriptor opacity is carried by each frame's vertex alpha.
            // Keep MAT0 alpha at one so it does not multiply the opacity a
            // second time.
            diffuse_alpha: 1.0,
            overlay_diffuse_alpha: None,
            overlay_directional_rgb: None,
            overlay_additive_rgb: None,
            specular_rgb: phase.specular_rgb,
            specular_power: phase.power,
            overlay_specular_rgb: None,
            overlay_specular_power: None,
            detail_uv_transform: [0.0, 0.0, 1.0, 1.0],
            overlay_uv_transform: None,
            overlay_detail_uv_transform: None,
            unlit: true,
            sky_nebula_stars: false,
            lightmap_mode: false,
            sky_far_depth: false,
            screen_tl: false,
        });
        phase_material_indices.push(index);
        phase_uv_transforms.push(phase.page_uv_transform);
        phase_native_flag_40.push(phase.native_flag_40);
        phase_directional_rgb.push(phase.directional_rgb);
        phase_additive_rgb.push(phase.additive_rgb);
    }
    let prepared = PreparedEffectMaterial {
        initial_pipeline_category: materials[phase_material_indices[0]].pipeline_category,
        document,
        phase_material_indices,
        phase_uv_transforms,
        phase_native_flag_40,
        phase_directional_rgb,
        phase_additive_rgb,
    };
    cache.insert(key, prepared.clone());
    Ok(prepared)
}

fn append_effect_material_animation(
    prepared: &PreparedEffectMaterial,
    range_index: usize,
    bindings: &mut Vec<MaterialAnimationBinding>,
) -> usize {
    let binding_index = bindings.len();
    bindings.push(MaterialAnimationBinding {
        initial_phase_index: 0,
        normalized_phase_override: None,
        ambient_fx_material_alpha: true,
        variants: vec![MaterialVariantSet {
            phase_material_indices: prepared.phase_material_indices.clone(),
            range_indices: vec![range_index],
            pipeline_category: prepared.initial_pipeline_category,
        }],
        base: MaterialPhaseBinding {
            document: prepared.document.clone(),
            animation_block_index: 0,
            wear_row_start_ms: 0,
            random_state: u32::try_from(binding_index).unwrap_or(u32::MAX),
            frozen_phase_index: None,
            phase_uv_transforms: prepared.phase_uv_transforms.clone(),
        },
        detail: None,
        overlay: None,
        overlay_detail: None,
        stage_textures: None,
    });
    binding_index
}

fn append_environment_gradient_material(
    materials: &mut Vec<VulkanStaticMaterial>,
) -> Result<usize, String> {
    let index = materials.len();
    let material_index = u16::try_from(index).map_err(|_| {
        "environment exceeds the available 16-bit material selector space".to_string()
    })?;
    materials.push(VulkanStaticMaterial {
        material_index,
        pipeline_category: 0,
        texture: solid_environment_texture([255, 255, 255, 255]),
        directional_rgb: [1.0; 3],
        additive_rgb: [0.0; 3],
        uv_transform: [0.0, 0.0, 1.0, 1.0],
        detail_texture: Some(solid_environment_texture([128, 128, 128, 255])),
        overlay_texture: None,
        overlay_detail_texture: None,
        diffuse_alpha: 1.0,
        overlay_diffuse_alpha: None,
        overlay_directional_rgb: None,
        overlay_additive_rgb: None,
        specular_rgb: [0.0; 3],
        specular_power: 0,
        overlay_specular_rgb: None,
        overlay_specular_power: None,
        detail_uv_transform: [0.0, 0.0, 1.0, 1.0],
        overlay_uv_transform: None,
        overlay_detail_uv_transform: None,
        unlit: true,
        sky_nebula_stars: false,
        lightmap_mode: false,
        sky_far_depth: true,
        screen_tl: false,
    });
    Ok(index)
}

fn shadow_atlas_texture() -> VulkanStaticTexture {
    let rgba8 = vec![0_u8; 256 * 256 * 4];
    VulkanStaticTexture {
        width: 256,
        height: 256,
        rgba8: rgba8.clone(),
        mip_levels: vec![VulkanStaticTextureMip {
            width: 256,
            height: 256,
            rgba8,
        }],
    }
}

fn append_shadow_material(materials: &mut Vec<VulkanStaticMaterial>) -> Result<usize, String> {
    let material_index = u16::try_from(materials.len()).map_err(|_| {
        "shadow material selector exceeds the available 16-bit material selector space".to_string()
    })?;
    let index = materials.len();
    materials.push(VulkanStaticMaterial {
        material_index,
        pipeline_category: 0,
        texture: shadow_atlas_texture(),
        directional_rgb: [1.0; 3],
        additive_rgb: [0.0; 3],
        uv_transform: [0.0, 0.0, 1.0, 1.0],
        detail_texture: Some(solid_environment_texture([255, 255, 255, 255])),
        overlay_texture: None,
        overlay_detail_texture: None,
        diffuse_alpha: 1.0,
        overlay_diffuse_alpha: None,
        overlay_directional_rgb: None,
        overlay_additive_rgb: None,
        specular_rgb: [0.0; 3],
        specular_power: 0,
        overlay_specular_rgb: None,
        overlay_specular_power: None,
        detail_uv_transform: [0.0, 0.0, 1.0, 1.0],
        overlay_uv_transform: None,
        overlay_detail_uv_transform: None,
        // Combiner mode 1 keeps the atlas alpha and the projected receiver's
        // per-vertex alpha while bypassing world lighting/fog.
        unlit: true,
        sky_nebula_stars: false,
        lightmap_mode: false,
        sky_far_depth: false,
        screen_tl: false,
    });
    Ok(index)
}

fn shadow_placeholder_vertices() -> Vec<VulkanStaticVertex> {
    [
        environment_vertex_with_alpha([0.0, 0.0, 0.0], [1.0; 3], 0.0, [0.0, 0.0]),
        environment_vertex_with_alpha([1.0, 0.0, 0.0], [1.0; 3], 0.0, [1.0, 0.0]),
        environment_vertex_with_alpha([0.0, 1.0, 0.0], [1.0; 3], 0.0, [0.0, 1.0]),
        environment_vertex_with_alpha([1.0, 1.0, 0.0], [1.0; 3], 0.0, [1.0, 1.0]),
    ]
    .to_vec()
}

fn shadow_triangle(positions: [[f32; 3]; 3], mask: u32) -> ShadowTriangle {
    let normal = normalize3(cross3(
        sub3(positions[1], positions[0]),
        sub3(positions[2], positions[0]),
    ))
    .unwrap_or([0.0, 0.0, 1.0]);
    ShadowTriangle {
        positions,
        normal,
        mask,
    }
}

fn terrain_shadow_receivers(
    terrain: &fparkan_terrain_format::LandMeshDocument,
) -> Result<Vec<ShadowTriangle>, String> {
    let assignments = terrain
        .face_lod_assignments()
        .map_err(|error| format!("select terrain LOD0 shadow receivers: {error}"))?;
    assignments
        .into_iter()
        .filter(|assignment| assignment.lod == TerrainLod::Lod0)
        .map(|assignment| {
            let face = terrain.faces.get(assignment.face_index).ok_or_else(|| {
                format!(
                    "terrain LOD assignment references missing face {}",
                    assignment.face_index
                )
            })?;
            let positions = source_terrain_face_positions(terrain, assignment.face_index)?;
            if !positions.iter().flatten().all(|value| value.is_finite()) {
                return Err("terrain shadow receiver contains a non-finite position".to_string());
            }
            Ok(shadow_triangle(positions, face.flags.0))
        })
        .collect()
}

fn source_terrain_face_positions(
    terrain: &fparkan_terrain_format::LandMeshDocument,
    face_index: usize,
) -> Result<[[f32; 3]; 3], String> {
    let face = terrain
        .faces
        .get(face_index)
        .ok_or_else(|| format!("terrain LOD assignment references missing face {face_index}"))?;
    let [first, second, third] = face.vertices;
    Ok([
        terrain
            .positions
            .get(usize::from(first))
            .copied()
            .ok_or_else(|| {
                format!("terrain face {face_index} references missing vertex {first}")
            })?,
        terrain
            .positions
            .get(usize::from(second))
            .copied()
            .ok_or_else(|| {
                format!("terrain face {face_index} references missing vertex {second}")
            })?,
        terrain
            .positions
            .get(usize::from(third))
            .copied()
            .ok_or_else(|| {
                format!("terrain face {face_index} references missing vertex {third}")
            })?,
    ])
}

fn static_mesh_shadow_triangles(mesh: &VulkanStaticMesh) -> Vec<ShadowTriangle> {
    mesh.indices
        .chunks_exact(3)
        .filter_map(|triangle| {
            let positions = [
                mesh.vertices
                    .get(usize::try_from(triangle[0]).ok()?)?
                    .position,
                mesh.vertices
                    .get(usize::try_from(triangle[1]).ok()?)?
                    .position,
                mesh.vertices
                    .get(usize::try_from(triangle[2]).ok()?)?
                    .position,
            ];
            positions
                .iter()
                .flatten()
                .all(|value| value.is_finite())
                .then_some(shadow_triangle(positions, 0))
        })
        .collect()
}

fn static_mesh_shadow_triangles_in_index_range(
    mesh: &VulkanStaticMesh,
    first_index: usize,
    index_count: usize,
) -> Result<Vec<ShadowTriangle>, String> {
    if index_count % 3 != 0 {
        return Err(format!(
            "dynamic shadow index range {first_index}..{} is not triangle-aligned",
            first_index.saturating_add(index_count)
        ));
    }
    let end = first_index
        .checked_add(index_count)
        .filter(|end| *end <= mesh.indices.len())
        .ok_or_else(|| {
            format!(
                "dynamic shadow index range {first_index}..{} is out of bounds",
                first_index.saturating_add(index_count)
            )
        })?;
    mesh.indices[first_index..end]
        .chunks_exact(3)
        .map(|triangle| {
            let positions =
                triangle
                    .iter()
                    .map(|index| {
                        mesh.vertices
                            .get(usize::try_from(*index).map_err(|_| {
                                "dynamic shadow vertex index exceeds usize".to_string()
                            })?)
                            .map(|vertex| vertex.position)
                            .ok_or_else(|| {
                                format!("dynamic shadow vertex index {index} is out of bounds")
                            })
                    })
                    .collect::<Result<Vec<_>, _>>()?;
            let positions: [[f32; 3]; 3] = positions
                .try_into()
                .map_err(|_| "dynamic shadow triangle did not have three vertices".to_string())?;
            if !positions.iter().flatten().all(|value| value.is_finite()) {
                return Err("dynamic shadow triangle contains a non-finite position".to_string());
            }
            Ok(shadow_triangle(positions, 0))
        })
        .collect()
}

fn refresh_dynamic_shadow_casters(
    casters: &mut [ShadowCaster],
    dynamic_casters: &[DynamicShadowCaster],
    mesh: &VulkanStaticMesh,
    pose_buffers: &[Vec<Option<NodePoseBuffer>>],
    mount_poses: &[Vec<Option<VulkanNodePose>>],
) -> Result<(), String> {
    for dynamic in dynamic_casters {
        let caster = casters.get_mut(dynamic.caster_index).ok_or_else(|| {
            format!(
                "dynamic shadow caster {} is outside the aggregate caster table",
                dynamic.caster_index
            )
        })?;
        let mut triangles = Vec::new();
        for &range_index in &dynamic.component_draw_range_indices {
            let range = mesh.draw_ranges.get(range_index).ok_or_else(|| {
                format!(
                    "dynamic shadow caster {} references missing draw range {range_index}",
                    dynamic.caster_index
                )
            })?;
            triangles.extend(static_mesh_shadow_triangles_in_index_range(
                mesh,
                usize::try_from(range.first_index)
                    .map_err(|_| "dynamic shadow draw range index exceeds usize".to_string())?,
                usize::try_from(range.index_count)
                    .map_err(|_| "dynamic shadow draw range count exceeds usize".to_string())?,
            )?);
        }
        if triangles.is_empty() {
            return Err(format!(
                "dynamic shadow caster {} lost its component triangles",
                dynamic.caster_index
            ));
        }
        let component_spheres = dynamic
            .component_spheres
            .iter()
            .filter_map(|source| {
                let mount_pose = if source.mounted {
                    mount_poses
                        .get(dynamic.object_index)
                        .and_then(|items| items.get(source.component_index))
                        .copied()
                        .flatten()
                } else {
                    None
                };
                if source.mounted && mount_pose.is_none() {
                    return None;
                }
                let node1_pose = if source.mounted {
                    pose_buffers
                        .get(dynamic.object_index)
                        .and_then(|items| items.get(source.component_index))
                        .and_then(Option::as_ref)
                        .and_then(|hierarchy| {
                            node38_pose_relative_to_root_from_hierarchy(hierarchy, 1)
                        })
                } else {
                    None
                };
                mounted_shadow_sphere(source.center, source.radius, mount_pose, node1_pose)
            })
            .collect::<Vec<_>>();
        if component_spheres.len() != dynamic.component_spheres.len() {
            return Err(format!(
                "dynamic shadow caster {} lost one or more component sphere poses",
                dynamic.caster_index
            ));
        }
        let mut refreshed = aggregate_shadow_caster(
            caster.id,
            caster.native_kind,
            dynamic.root_transform,
            dynamic.owner_scale,
            triangles,
            &component_spheres,
        )
        .ok_or_else(|| {
            format!(
                "dynamic shadow caster {} could not be rebuilt from current component poses",
                dynamic.caster_index
            )
        })?;
        // shortcut: animated native sphere parity is unverified. Rebuild from
        // the startup native bound, the current native bound, and current
        // triangles so the result is conservative and independent of history.
        refreshed.sphere = shadow_sphere_enclosing_current_geometry(
            dynamic.initial_sphere,
            refreshed.sphere,
            &refreshed.triangles,
        )?;
        *caster = refreshed;
    }
    Ok(())
}

fn shadow_sphere_enclosing_current_geometry(
    baseline: ShadowSphere,
    current_native: ShadowSphere,
    triangles: &[ShadowTriangle],
) -> Result<ShadowSphere, String> {
    let mut sphere = baseline;
    if !sphere.radius.is_finite()
        || sphere.radius < 0.0
        || !sphere.center.iter().all(|value| value.is_finite())
        || !current_native.radius.is_finite()
        || current_native.radius < 0.0
        || !current_native.center.iter().all(|value| value.is_finite())
    {
        return Err("animated shadow caster has an invalid bounding sphere".to_string());
    }

    let offset = sub3(current_native.center, sphere.center);
    let distance = offset[0].hypot(offset[1]).hypot(offset[2]);
    if !distance.is_finite() {
        return Err("animated shadow sphere distance is non-finite".to_string());
    }
    let required = distance + current_native.radius;
    if !required.is_finite() {
        return Err("animated shadow sphere radius is non-finite".to_string());
    }
    if current_native.radius >= distance + sphere.radius {
        sphere = current_native;
    } else if required > sphere.radius {
        let next_radius = sphere.radius + 0.5 * (required - sphere.radius);
        let shift = scale3(offset, (next_radius - sphere.radius) / distance);
        sphere.center = add3(sphere.center, shift);
        sphere.radius = next_radius;
    }

    for point in triangles.iter().flat_map(|triangle| triangle.positions) {
        if !point.iter().all(|value| value.is_finite()) {
            return Err("animated shadow triangle has a non-finite position".to_string());
        }
        let offset = sub3(point, sphere.center);
        let distance = offset[0].hypot(offset[1]).hypot(offset[2]);
        if !distance.is_finite() {
            return Err("animated shadow point distance is non-finite".to_string());
        }
        if distance <= sphere.radius {
            continue;
        }
        let next_radius = sphere.radius + 0.5 * (distance - sphere.radius);
        let center_shift = scale3(offset, (next_radius - sphere.radius) / distance);
        sphere.center = add3(sphere.center, center_shift);
        sphere.radius = next_radius;
    }

    Ok(sphere)
}

#[derive(Clone, Copy, Debug)]
struct ShadowComponentSphere {
    center: [f32; 3],
    radius: f32,
}

fn mounted_shadow_sphere(
    center: [f32; 3],
    radius: f32,
    mount_pose: Option<VulkanNodePose>,
    node1_pose: Option<VulkanNodePose>,
) -> Option<ShadowComponentSphere> {
    if !center.iter().all(|value| value.is_finite()) || !radius.is_finite() || radius <= 0.0 {
        return None;
    }
    let center = mount_pose.map_or(center, |parent_pose| {
        // The native mounted-unit sphere query keeps node 1's accumulated
        // rotation but replaces its translation with the accumulated parent
        // translation. This is deliberately different from the render mount
        // composition, which also carries node 1's translation.
        let rotation = node1_pose.map_or(parent_pose.rotation, |node_pose| {
            multiply_unit_quaternions(parent_pose.rotation, node_pose.rotation)
        });
        add3(
            parent_pose.translation,
            rotate_unit_vector(center, rotation),
        )
    });
    center
        .iter()
        .all(|value| value.is_finite())
        .then_some(ShadowComponentSphere { center, radius })
}

fn aggregate_shadow_caster(
    id: u32,
    native_kind: u32,
    transform: LegacyIron3dEulerTransform,
    scale: [f32; 3],
    triangles: Vec<ShadowTriangle>,
    component_spheres: &[ShadowComponentSphere],
) -> Option<ShadowCaster> {
    if triangles.is_empty() {
        return None;
    }
    let weight = component_spheres
        .iter()
        .map(|sphere| sphere.radius)
        .sum::<f32>();
    if !weight.is_finite() || weight <= f32::EPSILON {
        return None;
    }
    // Native 9510 aggregates visible root/EXTO spheres by radius-weighted
    // center, then encloses every component sphere around that center.
    let aggregate_center = component_spheres.iter().fold([0.0; 3], |sum, sphere| {
        add3(sum, scale3(sphere.center, sphere.radius))
    });
    let aggregate_center = scale3(aggregate_center, weight.recip());
    let radius = component_spheres
        .iter()
        .map(|sphere| length3(sub3(sphere.center, aggregate_center)).unwrap_or(0.0) + sphere.radius)
        .fold(0.0, f32::max);
    let max_scale = scale.iter().copied().fold(f32::NEG_INFINITY, f32::max);
    if !aggregate_center.iter().all(|value| value.is_finite())
        || !radius.is_finite()
        || radius <= f32::EPSILON
        || !max_scale.is_finite()
        || max_scale <= 0.0
    {
        return None;
    }
    // The native scale flag applies to the aggregate exactly once. The
    // mission Euler transform then rotates/translates that scaled sphere.
    let scaled_center = [
        aggregate_center[0] * scale[0],
        aggregate_center[1] * scale[1],
        aggregate_center[2] * scale[2],
    ];
    let center = transform.try_transform_scaled_point(scaled_center, [1.0; 3])?;
    let radius = radius * max_scale;
    if !center.iter().all(|value| value.is_finite()) || !radius.is_finite() {
        return None;
    }
    let world_axes = transform
        .try_row_major()
        .map(|matrix| {
            [
                [matrix[0], matrix[4], matrix[8]],
                [matrix[1], matrix[5], matrix[9]],
                [matrix[2], matrix[6], matrix[10]],
            ]
        })
        .unwrap_or([[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]]);
    Some(ShadowCaster {
        id,
        world_axes,
        sphere: ShadowSphere { center, radius },
        native_kind,
        triangles,
    })
}

fn shadow_lights(
    sky_frame: Option<&SkyFrame<'_>>,
    environment_frame: Option<&EnvironmentFrame>,
    renderer: &VulkanSmokeRenderer,
    control_point_lights: &[(VulkanPointLight, u32)],
) -> Vec<ShadowLight> {
    let mut lights = Vec::new();
    if let Some(sky_frame) = sky_frame {
        lights.extend(sky_frame.directional_lights.into_iter().enumerate().map(
            |(index, light)| {
                ShadowLight::Directional {
                    direction: light.direction,
                    rgb: light.color,
                    active: light.active,
                    // CSun's constructor marks both the sun (slot 0) and
                    // moon (slot 2) as primary. ShadowReference selects the
                    // first one for kind 3 and accumulates both active
                    // primary directions for ordinary objects (kind 4).
                    flags: (index == 0 || index == 2)
                        .then_some(SHADOW_PRIMARY_DIRECTIONAL_FLAG)
                        .unwrap_or(0),
                }
            },
        ));
    } else {
        let uniforms = renderer.frame_uniforms();
        lights.extend(
            uniforms
                .directional_lights
                .into_iter()
                .enumerate()
                .map(|(index, light)| ShadowLight::Directional {
                    direction: light.direction,
                    rgb: light.rgb,
                    active: light.active,
                    flags: (index == 0 || index == 2)
                        .then_some(SHADOW_PRIMARY_DIRECTIONAL_FLAG)
                        .unwrap_or(0),
                }),
        );
    }
    if let Some(environment_frame) = environment_frame {
        lights.extend(
            environment_frame
                .point_lights
                .iter()
                .map(|light| ShadowLight::Point {
                    position: light.position,
                    rgb: [light.color[0], light.color[1], light.color[2]],
                    range: light.range,
                    coefficients: light.attenuation,
                    active: light.active,
                    flags: 0,
                }),
        );
    } else {
        let point = renderer.frame_uniforms().point_light;
        lights.push(ShadowLight::Point {
            position: point.position,
            rgb: point.rgb,
            range: point.range,
            coefficients: point.coefficients,
            active: point.active,
            flags: 0,
        });
    }
    lights.extend(
        control_point_lights
            .iter()
            .map(|(light, flags)| ShadowLight::Point {
                position: light.position,
                rgb: light.rgb,
                range: light.range,
                coefficients: light.coefficients,
                active: light.active,
                flags: *flags,
            }),
    );
    lights
}

/// Native `Terrain30737` expands each caster sphere by 100 world units before
/// testing it against the six planes in the current world frustum. Filtering
/// here matters because `CShade` only accepts its first twenty candidates;
/// off-screen objects must not consume that budget.
const SHADOW_FRUSTUM_RADIUS_MARGIN: f32 = 100.0;

fn native_shadow_caster_visible(caster: &ShadowCaster, clip_from_world: [f32; 16]) -> bool {
    let radius = caster.sphere.radius + SHADOW_FRUSTUM_RADIUS_MARGIN;
    if !radius.is_finite() || radius < 0.0 || !caster.sphere.center.iter().all(|v| v.is_finite()) {
        return false;
    }

    // The camera matrix is row-major D3D-style storage. A world point is
    // transformed by p * M, so each clip coordinate uses one matrix column.
    // The six Vulkan clip half-spaces are x+w, -x+w, y+w, -y+w, z, and w-z.
    let planes = [
        [
            clip_from_world[0] + clip_from_world[3],
            clip_from_world[4] + clip_from_world[7],
            clip_from_world[8] + clip_from_world[11],
            clip_from_world[12] + clip_from_world[15],
        ],
        [
            -clip_from_world[0] + clip_from_world[3],
            -clip_from_world[4] + clip_from_world[7],
            -clip_from_world[8] + clip_from_world[11],
            -clip_from_world[12] + clip_from_world[15],
        ],
        [
            clip_from_world[1] + clip_from_world[3],
            clip_from_world[5] + clip_from_world[7],
            clip_from_world[9] + clip_from_world[11],
            clip_from_world[13] + clip_from_world[15],
        ],
        [
            -clip_from_world[1] + clip_from_world[3],
            -clip_from_world[5] + clip_from_world[7],
            -clip_from_world[9] + clip_from_world[11],
            -clip_from_world[13] + clip_from_world[15],
        ],
        [
            clip_from_world[2],
            clip_from_world[6],
            clip_from_world[10],
            clip_from_world[14],
        ],
        [
            clip_from_world[3] - clip_from_world[2],
            clip_from_world[7] - clip_from_world[6],
            clip_from_world[11] - clip_from_world[10],
            clip_from_world[15] - clip_from_world[14],
        ],
    ];
    planes.into_iter().all(|plane| {
        let normal_length =
            (plane[0].mul_add(plane[0], plane[1].mul_add(plane[1], plane[2] * plane[2]))).sqrt();
        if !normal_length.is_finite() || normal_length <= f32::EPSILON {
            return false;
        }
        let distance = plane[0].mul_add(
            caster.sphere.center[0],
            plane[1].mul_add(
                caster.sphere.center[1],
                plane[2].mul_add(caster.sphere.center[2], plane[3]),
            ),
        ) / normal_length;
        distance.is_finite() && distance > -radius
    })
}

fn native_visible_shadow_casters(
    casters: &[ShadowCaster],
    clip_from_world: [f32; 16],
) -> Vec<ShadowCaster> {
    casters
        .iter()
        .filter(|caster| native_shadow_caster_visible(caster, clip_from_world))
        .cloned()
        .collect()
}

fn append_shadow_frame_geometry(
    mesh: &mut VulkanStaticMesh,
    shadow_range: EnvironmentGpuRange,
    shadow_base_vertex: usize,
    shadow_base_index: usize,
    frame: &ShadowFrame,
) -> Result<VulkanDynamicDrawRange, String> {
    if shadow_base_vertex > mesh.vertices.len() || shadow_base_index > mesh.indices.len() {
        return Err("shadow dynamic base is outside the shared mesh".to_string());
    }
    mesh.vertices.truncate(shadow_base_vertex);
    mesh.indices.truncate(shadow_base_index);
    let vertex_base = u32::try_from(mesh.vertices.len())
        .map_err(|_| "shadow vertex base exceeds u32".to_string())?;
    let first_index = u32::try_from(mesh.indices.len())
        .map_err(|_| "shadow index base exceeds u32".to_string())?;
    if frame.indices.iter().any(|&index| {
        usize::try_from(index)
            .ok()
            .is_none_or(|index| index >= frame.vertices.len())
    }) {
        return Err("shadow frame index exceeds its vertex stream".to_string());
    }
    mesh.vertices.extend(frame.vertices.iter().map(|vertex| {
        environment_vertex_with_alpha_normal(
            vertex.position,
            [1.0; 3],
            vertex.alpha.clamp(0.0, 1.0),
            vertex.uv,
            vertex.normal,
        )
    }));
    mesh.indices.extend(
        frame
            .indices
            .iter()
            .map(|&index| {
                vertex_base
                    .checked_add(index)
                    .ok_or_else(|| "shadow index exceeds u32".to_string())
            })
            .collect::<Result<Vec<_>, _>>()?,
    );
    let index_count = u32::try_from(frame.indices.len())
        .map_err(|_| "shadow index count exceeds u32".to_string())?;
    if let Some(range) = mesh.draw_ranges.get_mut(shadow_range.range_index) {
        range.first_index = first_index;
        range.index_count = index_count;
    }
    Ok(VulkanDynamicDrawRange {
        range_index: shadow_range.range_index,
        first_index,
        index_count,
    })
}

fn shadow_atlas_texture_from_frame(frame: &ShadowFrame) -> VulkanStaticTexture {
    VulkanStaticTexture {
        width: 256,
        height: 256,
        rgba8: frame.atlas_rgba8.clone(),
        mip_levels: vec![VulkanStaticTextureMip {
            width: 256,
            height: 256,
            rgba8: frame.atlas_rgba8.clone(),
        }],
    }
}

fn append_environment_range(
    mesh: &mut VulkanStaticMesh,
    material_index: usize,
    vertices: Vec<VulkanStaticVertex>,
    local_indices: Vec<u32>,
    pipeline_state: LegacyPipelineState,
) -> Result<EnvironmentGpuRange, String> {
    if vertices.is_empty() || local_indices.is_empty() || !local_indices.len().is_multiple_of(3) {
        return Err("environment geometry range is empty or not triangle-aligned".to_string());
    }
    let vertex_start = mesh.vertices.len();
    let first_index = mesh.indices.len();
    let material_index = u16::try_from(material_index)
        .map_err(|_| "environment material selector exceeds u16".to_string())?;
    let vertex_start_u32 = u32::try_from(vertex_start)
        .map_err(|_| "environment vertex allocation exceeds u32".to_string())?;
    for index in local_indices {
        mesh.indices.push(
            vertex_start_u32
                .checked_add(index)
                .ok_or_else(|| "environment index exceeds u32".to_string())?,
        );
    }
    let index_count = u32::try_from(mesh.indices.len() - first_index)
        .map_err(|_| "environment index allocation exceeds u32".to_string())?;
    let vertex_capacity = vertices.len();
    mesh.vertices.extend(vertices);
    let first_index = u32::try_from(first_index)
        .map_err(|_| "environment first index exceeds u32".to_string())?;
    let range_index = mesh.draw_ranges.len();
    mesh.draw_ranges
        .push(fparkan_render_vulkan::VulkanStaticDrawRange {
            first_index,
            index_count,
            material_index,
            lightmap_index: u8::MAX,
            batch_flags: 0,
            pipeline_state,
            terrain_base_only: false,
            alpha_test_reference: VulkanStaticDrawRange::NATIVE_DEFAULT_ALPHA_TEST_REFERENCE,
        });
    Ok(EnvironmentGpuRange {
        range_index,
        vertex_start,
        vertex_capacity,
        material_index: usize::from(material_index),
    })
}

/// Reorders indexed draw segments without breaking the static mesh contract.
///
/// Draw ranges are required to cover one contiguous index buffer.  Changing
/// only their vector order therefore is insufficient when a background pass
/// must run before mission geometry: the corresponding index segments have to
/// move with them and every range receives a new `first_index`.
fn reorder_draw_ranges(
    mesh: &mut VulkanStaticMesh,
    old_order: &[usize],
) -> Result<Vec<usize>, String> {
    if old_order.len() != mesh.draw_ranges.len() {
        return Err("draw-range reorder does not cover the whole mesh".to_string());
    }
    let mut seen = vec![false; mesh.draw_ranges.len()];
    let old_ranges = mesh.draw_ranges.clone();
    let old_indices = mesh.indices.clone();
    let mut indices = Vec::with_capacity(old_indices.len());
    let mut ranges = Vec::with_capacity(old_ranges.len());
    let mut remap = vec![usize::MAX; old_ranges.len()];
    for (new_index, &old_index) in old_order.iter().enumerate() {
        if old_index >= old_ranges.len() || seen[old_index] {
            return Err("draw-range reorder contains a duplicate or invalid range".to_string());
        }
        seen[old_index] = true;
        let old_range = old_ranges[old_index];
        let first = usize::try_from(old_range.first_index)
            .map_err(|_| "draw-range first index exceeds addressable memory".to_string())?;
        let count = usize::try_from(old_range.index_count)
            .map_err(|_| "draw-range index count exceeds addressable memory".to_string())?;
        let end = first
            .checked_add(count)
            .ok_or_else(|| "draw-range index segment overflows address space".to_string())?;
        let segment = old_indices
            .get(first..end)
            .ok_or_else(|| "draw-range index segment is outside the mesh".to_string())?;
        let first_index = u32::try_from(indices.len())
            .map_err(|_| "reordered index buffer exceeds u32".to_string())?;
        indices.extend_from_slice(segment);
        let mut range = old_range;
        range.first_index = first_index;
        ranges.push(range);
        remap[old_index] = new_index;
    }
    if seen.iter().any(|seen| !seen) || indices.len() != old_indices.len() {
        return Err("draw-range reorder does not cover the whole index buffer".to_string());
    }
    mesh.indices = indices;
    mesh.draw_ranges = ranges;
    Ok(remap)
}

fn remap_dynamic_shadow_caster_draw_ranges(
    dynamic_casters: &mut [DynamicShadowCaster],
    range_remap: &[usize],
) -> Result<(), String> {
    let remapped = dynamic_casters
        .iter()
        .map(|dynamic| {
            dynamic
                .component_draw_range_indices
                .iter()
                .map(|&range_index| {
                    range_remap.get(range_index).copied().ok_or_else(|| {
                        format!(
                            "dynamic shadow caster {} references missing pre-reorder draw range {range_index}",
                            dynamic.caster_index
                        )
                    })
                })
                .collect::<Result<Vec<_>, _>>()
        })
        .collect::<Result<Vec<_>, _>>()?;
    for (dynamic, ranges) in dynamic_casters.iter_mut().zip(remapped) {
        dynamic.component_draw_range_indices = ranges;
    }
    Ok(())
}

fn quad_indices(slot_count: usize) -> Result<Vec<u32>, String> {
    let mut indices = Vec::with_capacity(
        slot_count
            .checked_mul(6)
            .ok_or_else(|| "environment quad index count overflow".to_string())?,
    );
    for slot in 0..slot_count {
        let base = u32::try_from(
            slot.checked_mul(4)
                .ok_or_else(|| "environment quad vertex count overflow".to_string())?,
        )
        .map_err(|_| "environment quad vertex count exceeds u32".to_string())?;
        indices.extend_from_slice(&[base, base + 1, base + 2, base + 2, base + 1, base + 3]);
    }
    Ok(indices)
}

fn placeholder_quad_vertices(
    camera: &PreviewCameraFrame,
    slot_count: usize,
    size: f32,
) -> Vec<VulkanStaticVertex> {
    let center = add3(
        camera.position,
        scale3(camera.forward(), camera.far_plane * 0.5),
    );
    let right = scale3(camera.right(), size);
    let up = scale3(camera.up(), size);
    (0..slot_count)
        .flat_map(|_| {
            [
                environment_vertex(sub3(sub3(center, right), up), [1.0; 3], [0.0, 1.0]),
                environment_vertex(add3(sub3(center, up), right), [1.0; 3], [1.0, 1.0]),
                environment_vertex(add3(sub3(center, right), up), [1.0; 3], [0.0, 0.0]),
                environment_vertex(add3(add3(center, right), up), [1.0; 3], [1.0, 0.0]),
            ]
        })
        .collect()
}

fn screen_gradient_quad_vertices(
    camera: &PreviewCameraFrame,
    viewport: [f32; 2],
    color: [f32; 3],
) -> [VulkanStaticVertex; 4] {
    let width = viewport[0].max(1.0);
    let height = viewport[1].max(1.0);
    let aspect = width / height;
    let fov = camera.vertical_fov;
    // The quad is placed close to the camera and drawn with depth disabled.
    // It therefore covers the complete projected viewport while the later
    // dome, terrain, and object ranges provide their own depth-tested detail.
    let distance = 1.0_f32;
    let half_height = distance * (fov * 0.5).tan() * 1.05;
    let half_width = half_height * aspect;
    let center = add3(camera.position, scale3(camera.forward(), distance));
    let right = scale3(camera.right(), half_width);
    let up = scale3(camera.up(), half_height);
    [
        environment_vertex(sub3(sub3(center, right), up), color, [0.0, 1.0]),
        environment_vertex(add3(sub3(center, up), right), color, [1.0, 1.0]),
        environment_vertex(add3(sub3(center, right), up), color, [0.0, 0.0]),
        environment_vertex(add3(add3(center, right), up), color, [1.0, 0.0]),
    ]
}

impl EnvironmentGpuScene {
    fn transparent_background_range_indices(&self) -> Vec<usize> {
        self.sky_layers
            .iter()
            .filter(|layer| {
                matches!(
                    layer.kind,
                    SkyPassKind::NebulaStars | SkyPassKind::DomeGradient | SkyPassKind::Clouds
                )
            })
            .map(|layer| layer.range.range_index)
            .collect()
    }

    fn fixed_range_indices(&self) -> HashSet<usize> {
        self.sky_layers
            .iter()
            .map(|layer| layer.range.range_index)
            .chain(self.sprites.iter().map(|sprite| sprite.range.range_index))
            .chain([
                self.rain.range_index,
                self.snow.range_index,
                self.lightning.range_index,
            ])
            .collect()
    }

    fn new(
        mesh: &mut VulkanStaticMesh,
        native_handedness_by_range: &mut HashMap<usize, i8>,
        type16_present_ranges: &mut HashSet<usize>,
        materials: &mut Vec<VulkanStaticMaterial>,
        preview_material_animations: &mut Vec<MaterialAnimationBinding>,
        ambient_effect_slots: &mut [AmbientEffectGpuSlot],
        dynamic_shadow_casters: &mut [DynamicShadowCaster],
        sun_occlusion_range_indices: &mut Vec<usize>,
        environment_materials: &SkyMaterials,
        material_assets: &HashMap<String, EnvironmentMaterialAsset>,
        sky_mesh: &SkyMesh,
        camera: &PreviewCameraFrame,
        shadow_range_index: &mut usize,
    ) -> Result<Self, String> {
        let mut names = HashMap::new();
        let mut material_animations = Vec::new();
        let mut material_indices = [None; 9];
        let fallback_names = SkyMaterials::default();
        for row in 0..9 {
            let name = environment_materials
                .material_name(row)
                .or_else(|| fallback_names.material_name(row))
                .unwrap_or("ENVIRONMENT");
            let index = append_environment_material(
                materials,
                &mut names,
                material_assets,
                &mut material_animations,
                name,
                row,
            )?;
            material_indices[row] = Some(index);
        }
        let gradient_material_index = append_environment_gradient_material(materials)?;
        let nebula_material_index = material_indices[0]
            .ok_or_else(|| "nebula material selector is unavailable".to_string())?;
        let stars_material_index = material_indices[1]
            .ok_or_else(|| "stars material selector is unavailable".to_string())?;
        // Native sky mode 4 uses one descriptor set: TEX0 is the nebula and
        // TEX1 is the independently animated stars texture whose alpha chooses
        // the contribution. Keep the stars MAT0 binding as the nebula binding's
        // detail stage; do not form a Cartesian product of the two phase rows.
        let (nebula_binding_index, nebula_phase_materials) =
            find_material_animation_variant(&material_animations, nebula_material_index)
                .ok_or_else(|| {
                    format!("MAT0 sky material {nebula_material_index} has no phase variants")
                })?;
        let (stars_binding_index, stars_phase_materials) =
            find_material_animation_variant(&material_animations, stars_material_index)
                .ok_or_else(|| {
                    format!("MAT0 sky material {stars_material_index} has no phase variants")
                })?;
        if stars_phase_materials.is_empty() {
            return Err("stars material has no phase variants".to_string());
        }
        let stars_descriptors = stars_phase_materials
            .iter()
            .map(|&material_index| {
                let material = materials.get(material_index).ok_or_else(|| {
                    format!("stars material descriptor {material_index} is unavailable")
                })?;
                Ok((material.texture.clone(), material.uv_transform))
            })
            .collect::<Result<Vec<_>, String>>()?;
        let stars_binding = material_animations
            .get(stars_binding_index)
            .ok_or_else(|| "stars material animation binding is unavailable".to_string())?
            .base
            .clone();
        let stars_stage_textures = stars_descriptors
            .iter()
            .map(|(texture, _)| texture.clone())
            .collect();
        let stars_initial_uv = stars_descriptors
            .first()
            .map(|(_, uv_transform)| *uv_transform)
            .unwrap_or([0.0, 0.0, 1.0, 1.0]);
        for &material_index in &nebula_phase_materials {
            let stars_texture = stars_descriptors
                .first()
                .map(|(texture, _)| texture.clone())
                .ok_or_else(|| "stars material descriptor is unavailable".to_string())?;
            let nebula = materials.get_mut(material_index).ok_or_else(|| {
                format!("nebula material descriptor {material_index} is unavailable")
            })?;
            nebula.detail_texture = Some(stars_texture);
            nebula.detail_uv_transform = stars_initial_uv;
            nebula.sky_nebula_stars = true;
        }
        let nebula_binding = material_animations
            .get_mut(nebula_binding_index)
            .ok_or_else(|| "nebula material animation binding is unavailable".to_string())?;
        nebula_binding.detail = Some(stars_binding);
        nebula_binding.stage_textures = Some(MaterialStageTextures {
            detail: Some(stars_stage_textures),
            overlay: None,
            overlay_detail: None,
            // Force TEX1 to the independently sampled stars phase on the first
            // frame, including when the initial star descriptor is already set.
            applied_material_phases: HashMap::new(),
        });
        let lightning_material_index = append_environment_material(
            materials,
            &mut names,
            material_assets,
            &mut material_animations,
            "env_lightning",
            3,
        )?;

        let mut scene = Self {
            material_animations,
            sky_layers: Vec::with_capacity(4),
            sprites: Vec::with_capacity(ENVIRONMENT_SPRITE_ROWS.len() + ENVIRONMENT_FLARE_SLOTS),
            rain: EnvironmentGpuRange {
                range_index: 0,
                vertex_start: 0,
                vertex_capacity: 0,
                material_index: material_indices[8].unwrap_or(0),
            },
            snow: EnvironmentGpuRange {
                range_index: 0,
                vertex_start: 0,
                vertex_capacity: 0,
                material_index: material_indices[7].unwrap_or(0),
            },
            lightning: EnvironmentGpuRange {
                range_index: 0,
                vertex_start: 0,
                vertex_capacity: 0,
                material_index: lightning_material_index,
            },
            lightning_material_index,
        };

        let screen_range = append_environment_range(
            mesh,
            gradient_material_index,
            screen_gradient_quad_vertices(camera, [16.0, 9.0], [1.0; 3]).to_vec(),
            quad_indices(1)?,
            world_pipeline_state(LegacyBlendMode::Opaque, LegacyDepthMode::Disabled),
        )?;
        scene.sky_layers.push(EnvironmentSkyLayer {
            kind: SkyPassKind::ScreenGradient,
            stage: None,
            secondary_stage: None,
            material_index: gradient_material_index,
            diffuse_alpha: 1.0,
            static_directional_rgb: [1.0; 3],
            static_additive_rgb: [0.0; 3],
            translation_z: 0.0,
            range: screen_range,
        });

        let nebula_material = materials
            .get(nebula_material_index)
            .ok_or_else(|| "nebula material descriptor is unavailable".to_string())?;
        let nebula_vertices = sky_mesh
            .vertices
            .iter()
            .map(|vertex| {
                let color = vertex.color_rgba();
                environment_vertex_with_alpha_normal(
                    add3(vertex.position, camera.position),
                    [color[0], color[1], color[2]],
                    color[3],
                    vertex.uv[0],
                    sky_normal(vertex.normal),
                )
            })
            .collect();
        let nebula_range = append_environment_range(
            mesh,
            nebula_material_index,
            nebula_vertices,
            sky_mesh.indices.clone(),
            world_pipeline_state(LegacyBlendMode::SourceAlpha, LegacyDepthMode::TestReadOnly),
        )?;
        register_material_range(
            &mut scene.material_animations,
            nebula_material_index,
            nebula_range.range_index,
        );
        scene.sky_layers.push(EnvironmentSkyLayer {
            kind: SkyPassKind::NebulaStars,
            stage: Some(0),
            secondary_stage: Some(1),
            material_index: nebula_material_index,
            diffuse_alpha: nebula_material.diffuse_alpha,
            static_directional_rgb: nebula_material.directional_rgb,
            static_additive_rgb: nebula_material.additive_rgb,
            translation_z: 0.0,
            range: nebula_range,
        });

        let dome_vertices = sky_mesh
            .vertices
            .iter()
            .map(|vertex| {
                let color = vertex.color_rgba();
                environment_vertex_with_alpha_normal(
                    add3(vertex.position, camera.position),
                    [color[0], color[1], color[2]],
                    color[3],
                    [0.0, 0.0],
                    sky_normal(vertex.normal),
                )
            })
            .collect();
        let dome_range = append_environment_range(
            mesh,
            gradient_material_index,
            dome_vertices,
            sky_mesh.indices.clone(),
            world_pipeline_state(LegacyBlendMode::SourceAlpha, LegacyDepthMode::TestReadOnly),
        )?;
        scene.sky_layers.push(EnvironmentSkyLayer {
            kind: SkyPassKind::DomeGradient,
            stage: None,
            secondary_stage: None,
            material_index: gradient_material_index,
            diffuse_alpha: 1.0,
            static_directional_rgb: [1.0; 3],
            static_additive_rgb: [0.0; 3],
            translation_z: 0.0,
            range: dome_range,
        });

        let clouds_material_index = material_indices[2]
            .ok_or_else(|| "cloud material selector is unavailable".to_string())?;
        let clouds_material = materials
            .get(clouds_material_index)
            .ok_or_else(|| "cloud material descriptor is unavailable".to_string())?;
        let clouds_vertices = sky_mesh
            .vertices
            .iter()
            .map(|vertex| {
                let color = vertex.color_rgba();
                environment_vertex_with_alpha_normal(
                    add3(add3(vertex.position, camera.position), [0.0, 0.0, -5000.0]),
                    [color[0], color[1], color[2]],
                    color[3],
                    vertex.uv[2],
                    sky_normal(vertex.normal),
                )
            })
            .collect();
        let clouds_range = append_environment_range(
            mesh,
            clouds_material_index,
            clouds_vertices,
            sky_mesh.indices.clone(),
            world_pipeline_state(LegacyBlendMode::SourceAlpha, LegacyDepthMode::TestReadOnly),
        )?;
        register_material_range(
            &mut scene.material_animations,
            clouds_material_index,
            clouds_range.range_index,
        );
        scene.sky_layers.push(EnvironmentSkyLayer {
            kind: SkyPassKind::Clouds,
            stage: Some(2),
            secondary_stage: None,
            material_index: clouds_material_index,
            diffuse_alpha: clouds_material.diffuse_alpha,
            static_directional_rgb: clouds_material.directional_rgb,
            static_additive_rgb: clouds_material.additive_rgb,
            translation_z: -5000.0,
            range: clouds_range,
        });

        let sprite_size = (camera.far_plane * 0.01).max(1.0);
        for row in ENVIRONMENT_SPRITE_ROWS {
            let material_index = material_indices[row]
                .ok_or_else(|| format!("sky sprite row {row} has no material selector"))?;
            let range = append_environment_range(
                mesh,
                material_index,
                placeholder_quad_vertices(camera, 1, sprite_size),
                quad_indices(1)?,
                world_pipeline_state(LegacyBlendMode::SourceAlpha, LegacyDepthMode::TestReadOnly),
            )?;
            register_material_range(
                &mut scene.material_animations,
                material_index,
                range.range_index,
            );
            scene.sprites.push(EnvironmentSpriteLayer {
                row,
                material_index,
                diffuse_alpha: materials
                    .get(material_index)
                    .map_or(1.0, |material| material.diffuse_alpha),
                flare_index: None,
                range,
            });
        }

        for flare_index in 0..ENVIRONMENT_FLARE_SLOTS {
            let row = SKY_FLARE_ROWS[flare_index];
            let material_index = material_indices[row]
                .ok_or_else(|| format!("sky flare row {row} has no material selector"))?;
            let range = append_environment_range(
                mesh,
                material_index,
                placeholder_quad_vertices(camera, 1, sprite_size),
                quad_indices(1)?,
                world_pipeline_state(LegacyBlendMode::Additive, LegacyDepthMode::TestReadOnly),
            )?;
            register_material_range(
                &mut scene.material_animations,
                material_index,
                range.range_index,
            );
            scene.sprites.push(EnvironmentSpriteLayer {
                row,
                material_index,
                diffuse_alpha: materials
                    .get(material_index)
                    .map_or(1.0, |material| material.diffuse_alpha),
                flare_index: Some(flare_index),
                range,
            });
        }

        let particle_indices = quad_indices(ENVIRONMENT_PARTICLE_SLOTS)?;
        scene.rain = append_environment_range(
            mesh,
            material_indices[8]
                .ok_or_else(|| "rain material selector is unavailable".to_string())?,
            placeholder_quad_vertices(camera, ENVIRONMENT_PARTICLE_SLOTS, 0.25),
            particle_indices.clone(),
            world_pipeline_state(LegacyBlendMode::SourceAlpha, LegacyDepthMode::TestReadOnly),
        )?;
        register_material_range(
            &mut scene.material_animations,
            scene.rain.material_index,
            scene.rain.range_index,
        );
        scene.snow = append_environment_range(
            mesh,
            material_indices[7]
                .ok_or_else(|| "snow material selector is unavailable".to_string())?,
            placeholder_quad_vertices(camera, ENVIRONMENT_PARTICLE_SLOTS, 0.25),
            particle_indices,
            world_pipeline_state(LegacyBlendMode::SourceAlpha, LegacyDepthMode::TestReadOnly),
        )?;
        register_material_range(
            &mut scene.material_animations,
            scene.snow.material_index,
            scene.snow.range_index,
        );
        scene.lightning = append_environment_range(
            mesh,
            lightning_material_index,
            placeholder_quad_vertices(camera, 1, sprite_size),
            quad_indices(1)?,
            world_pipeline_state(LegacyBlendMode::SourceAlpha, LegacyDepthMode::TestReadOnly),
        )?;
        register_material_range(
            &mut scene.material_animations,
            scene.lightning.material_index,
            scene.lightning.range_index,
        );

        // Preserve the native sky order while keeping the indexed mesh
        // contiguous.  The screen gradient must be the first draw, and the
        // cloud dome follows all directional sprites.  Reordering the range
        // metadata alone would leave first_index values pointing into the old
        // segment order, so move each index segment together with its range.
        let range_for_kind = |kind: SkyPassKind| {
            scene
                .sky_layers
                .iter()
                .find(|layer| layer.kind == kind)
                .map(|layer| layer.range.range_index)
        };
        let screen_index = range_for_kind(SkyPassKind::ScreenGradient)
            .ok_or_else(|| "screen gradient range was not allocated".to_string())?;
        let nebula_index = range_for_kind(SkyPassKind::NebulaStars)
            .ok_or_else(|| "nebula sky range was not allocated".to_string())?;
        let dome_index = range_for_kind(SkyPassKind::DomeGradient)
            .ok_or_else(|| "dome gradient range was not allocated".to_string())?;
        let cloud_index = range_for_kind(SkyPassKind::Clouds)
            .ok_or_else(|| "cloud sky range was not allocated".to_string())?;
        let sprite_indices = scene
            .sprites
            .iter()
            .map(|sprite| sprite.range.range_index)
            .collect::<Vec<_>>();
        if sprite_indices.is_empty() {
            return Err("sky sprite ranges were not allocated".to_string());
        }
        let rain_index = scene.rain.range_index;
        let snow_index = scene.snow.range_index;
        let lightning_index = scene.lightning.range_index;
        let environment_indices = [
            screen_index,
            nebula_index,
            dome_index,
            cloud_index,
            rain_index,
            snow_index,
            lightning_index,
            *shadow_range_index,
        ]
        .into_iter()
        .chain(sprite_indices.iter().copied())
        .collect::<HashSet<_>>();
        let old_range_count = mesh.draw_ranges.len();
        let mut old_order = Vec::with_capacity(old_range_count);
        old_order.push(screen_index);
        old_order.extend((0..old_range_count).filter(|index| {
            !environment_indices.contains(index)
                && *index != screen_index
                && *index != nebula_index
                && *index != dome_index
                && *index != cloud_index
        }));
        old_order.push(*shadow_range_index);
        old_order.extend([nebula_index, dome_index, cloud_index]);
        old_order.extend(sprite_indices.iter().copied());
        old_order.extend([rain_index, snow_index, lightning_index]);
        let remap = reorder_draw_ranges(mesh, &old_order)?;
        let mut remapped_handedness = HashMap::with_capacity(native_handedness_by_range.len());
        for (old_range_index, handedness) in std::mem::take(native_handedness_by_range) {
            let new_range_index = remap.get(old_range_index).copied().ok_or_else(|| {
                format!("native MSH draw range remap is missing range {old_range_index}")
            })?;
            remapped_handedness.insert(new_range_index, handedness);
        }
        *native_handedness_by_range = remapped_handedness;
        let mut remapped_type16_present_ranges =
            HashSet::with_capacity(type16_present_ranges.len());
        for old_range_index in std::mem::take(type16_present_ranges) {
            let new_range_index = remap.get(old_range_index).copied().ok_or_else(|| {
                format!("type-16 MSH draw range remap is missing range {old_range_index}")
            })?;
            remapped_type16_present_ranges.insert(new_range_index);
        }
        *type16_present_ranges = remapped_type16_present_ranges;
        remap_dynamic_shadow_caster_draw_ranges(dynamic_shadow_casters, &remap)?;
        for layer in &mut scene.sky_layers {
            layer.range.range_index = *remap
                .get(layer.range.range_index)
                .ok_or_else(|| "sky draw range remap is out of bounds".to_string())?;
        }
        for sprite in &mut scene.sprites {
            sprite.range.range_index = *remap
                .get(sprite.range.range_index)
                .ok_or_else(|| "sky sprite draw range remap is out of bounds".to_string())?;
        }
        scene.rain.range_index = *remap
            .get(scene.rain.range_index)
            .ok_or_else(|| "rain draw range remap is out of bounds".to_string())?;
        scene.snow.range_index = *remap
            .get(scene.snow.range_index)
            .ok_or_else(|| "snow draw range remap is out of bounds".to_string())?;
        scene.lightning.range_index = *remap
            .get(scene.lightning.range_index)
            .ok_or_else(|| "lightning draw range remap is out of bounds".to_string())?;
        remap_material_animation_ranges(&mut scene.material_animations, &remap)?;
        remap_material_animation_ranges(preview_material_animations, &remap)?;
        for slot in ambient_effect_slots {
            slot.range.range_index = *remap
                .get(slot.range.range_index)
                .ok_or_else(|| "ambient FX draw range remap is out of bounds".to_string())?;
            for range in &mut slot.additional_particle_ranges {
                range.range_index = *remap.get(range.range_index).ok_or_else(|| {
                    "ambient FX particle draw range remap is out of bounds".to_string()
                })?;
            }
        }
        for range_index in sun_occlusion_range_indices {
            *range_index = *remap
                .get(*range_index)
                .ok_or_else(|| "sun occlusion range remap is out of bounds".to_string())?;
        }
        *shadow_range_index = *remap
            .get(*shadow_range_index)
            .ok_or_else(|| "shadow draw range remap is out of bounds".to_string())?;
        Ok(scene)
    }

    fn update(
        &mut self,
        mesh: &mut VulkanStaticMesh,
        renderer: &mut VulkanSmokeRenderer,
        material_update: &MaterialFrameUpdate,
        sky_frame: &SkyFrame,
        sky_mesh: &SkyMesh,
        environment_frame: &EnvironmentFrame,
        camera: &PreviewCameraFrame,
        viewport: [f32; 2],
        terrain: &TerrainWorld,
        sun_occlusion_range_indices: &[usize],
    ) -> Result<(), String> {
        let active_materials = &material_update.active_materials;
        // Resolve the native glare once for the frame.  CSky feeds the
        // boosted primary color back into the light manager and uses the
        // positive boost delta for both the screen-gradient horizon floor and
        // the dome palette clamp.
        let projected_sun =
            project_direction_pixels(camera, sky_frame.sun.geometry_direction(), viewport)
                .unwrap_or([f32::NAN; 2]);
        let optics = sky_frame
            .sun_optics(SunVisibility {
                projected_sun,
                viewport,
                view_forward: camera.forward(),
                // Flares use the same terrain/object ray query as the native
                // visibility gate. The sun sprite itself deliberately stays
                // independent of this test, matching the native layer's
                // `requires_occlusion` split.
                unoccluded: native_sun_unoccluded_with_world(
                    terrain,
                    mesh,
                    sun_occlusion_range_indices,
                    camera,
                    sky_frame.sun.geometry_direction(),
                ),
            })
            .ok();
        let glare_rgb_delta = optics.map_or([0.0; 3], |optics| {
            std::array::from_fn(|index| {
                (optics.primary_color[index] - sky_frame.sun.color[index]).max(0.0)
            })
        });
        let gradient = sky_frame.screen_gradient(camera.native_sky_heading(), glare_rgb_delta);
        if let Some(optics) = optics {
            let mut uniforms = renderer.frame_uniforms();
            if sky_frame.sun.active {
                uniforms.directional_lights[0].rgb = optics.primary_color;
            }
            renderer
                .set_frame_uniforms(uniforms)
                .map_err(|error| format!("update glare light uniforms: {error}"))?;
        }
        let gradient_rgba = gradient.color.rgba();
        for layer in &self.sky_layers {
            let range = layer.range;
            let destination = mesh
                .vertices
                .get_mut(range.vertex_start..range.vertex_start + range.vertex_capacity)
                .ok_or_else(|| "sky vertex allocation is out of bounds".to_string())?;
            let pass_frame = sky_frame
                .passes
                .iter()
                .find(|pass| pass.kind == layer.kind)
                .ok_or_else(|| format!("sky frame is missing {:?} pass", layer.kind))?;
            match layer.kind {
                SkyPassKind::ScreenGradient => {
                    if destination.len() != 4 {
                        return Err("screen gradient vertex allocation changed".to_string());
                    }
                    destination.copy_from_slice(&screen_gradient_quad_vertices(
                        camera,
                        viewport,
                        [gradient_rgba[0], gradient_rgba[1], gradient_rgba[2]],
                    ));
                }
                SkyPassKind::NebulaStars | SkyPassKind::DomeGradient | SkyPassKind::Clouds => {
                    if destination.len() != sky_mesh.vertices.len() {
                        return Err(
                            "sky mesh vertex count changed after GPU allocation".to_string()
                        );
                    }
                    for (target, source) in destination.iter_mut().zip(&sky_mesh.vertices) {
                        let source_color = match layer.kind {
                            // Native mode 4 receives a white DIFFUSE and
                            // chooses nebula/stars through TEX1 alpha.
                            SkyPassKind::NebulaStars | SkyPassKind::Clouds => [1.0; 4],
                            SkyPassKind::DomeGradient => {
                                gradient.clamp_dome_color(source.color).rgba()
                            }
                            SkyPassKind::ScreenGradient => unreachable!(),
                        };
                        target.position = add3(
                            add3(source.position, camera.position),
                            [0.0, 0.0, layer.translation_z],
                        );
                        target.color = [source_color[0], source_color[1], source_color[2]];
                        target.uv = layer
                            .stage
                            .and_then(|stage| source.uv.get(stage).copied())
                            .unwrap_or([0.0, 0.0]);
                        target.detail_uv = layer
                            .secondary_stage
                            .and_then(|stage| source.uv.get(stage).copied())
                            .unwrap_or([0.0, 0.0]);
                        target.normal = sky_normal(source.normal);
                        target.overlay_alpha = source_color[3];
                    }
                }
            }
            let material_index = active_materials
                .get(&range.range_index)
                .map(|state| state.material_index)
                .unwrap_or(layer.material_index);
            if !active_materials.contains_key(&range.range_index) {
                renderer
                    .set_material_alphas(material_index, layer.diffuse_alpha.clamp(0.0, 1.0), 0.0)
                    .map_err(|error| format!("update sky material alpha: {error}"))?;
            }
            if layer.kind == SkyPassKind::Clouds {
                let directional_rgb = pass_frame
                    .material_color
                    .unwrap_or(layer.static_directional_rgb);
                renderer
                    .set_material_lighting(
                        material_index,
                        directional_rgb,
                        layer.static_additive_rgb,
                    )
                    .map_err(|error| format!("update cloud material lighting: {error}"))?;
            }
            renderer
                .set_draw_range_index_count(
                    range.range_index,
                    if layer.kind == SkyPassKind::ScreenGradient {
                        6
                    } else {
                        u32::try_from(sky_mesh.indices.len())
                            .map_err(|_| "sky index count exceeds u32".to_string())?
                    },
                )
                .map_err(|error| format!("update sky draw range: {error}"))?;
        }

        // Flares share their source material row, so their packed alpha lives
        // in each vertex.  Upload the shared phase alpha once before emitting
        // the twelve fixed-capacity ranges.
        let mut flare_materials = HashMap::new();
        for sprite in &self.sprites {
            if sprite.flare_index.is_some()
                && !active_materials.contains_key(&sprite.range.range_index)
            {
                flare_materials.insert(sprite.material_index, sprite.diffuse_alpha);
            }
        }
        for (material_index, diffuse_alpha) in flare_materials {
            renderer
                .set_material_alphas(material_index, diffuse_alpha.clamp(0.0, 1.0), 0.0)
                .map_err(|error| format!("update sky flare alpha: {error}"))?;
        }
        for sprite in &self.sprites {
            let mut active = false;
            let mut vertices = None;
            let mut material_alpha = 0.0;
            if let Some(flare_index) = sprite.flare_index {
                if let Some(flare) =
                    optics.and_then(|optics| optics.flares.get(flare_index).copied())
                {
                    let direction = screen_ray_from_pixels(camera, flare.center_pixels, viewport);
                    active = flare.active && direction.is_some() && flare.color[3] > 0.0;
                    if let Some(direction) = direction {
                        vertices = Some(sprite_quad_vertices_pixels(
                            camera,
                            direction,
                            (camera.far_plane * 0.5).max(camera.near_plane * 2.0),
                            flare.half_size_pixels,
                            flare.half_size_pixels,
                            viewport,
                            [flare.color[0], flare.color[1], flare.color[2]],
                            flare.color[3],
                            flare.uv,
                        ));
                    }
                }
            } else if let Some(frame) = sprite_frame_for_row(sky_frame, sprite.row) {
                let projected = project_direction_pixels(camera, frame.direction, viewport);
                active = frame.active
                    && frame.intensity > 0.0
                    && projected.is_some_and(|center| {
                        center[0] >= 0.0
                            && center[0] <= viewport[0]
                            && center[1] >= 0.0
                            && center[1] <= viewport[1]
                    });
                if active {
                    if let Ok([half_width, half_height]) = sprite_half_size_pixels(
                        frame.size_values,
                        viewport,
                        horizontal_fov(camera, viewport[0] / viewport[1].max(1.0)),
                    ) {
                        if ENVIRONMENT_SPRITE_ROWS.contains(&sprite.row) {
                            if let Some(center_pixels) = projected {
                                vertices = Some(screen_tl_quad_vertices_pixels(
                                    center_pixels,
                                    half_width,
                                    half_height,
                                    viewport,
                                    frame.color,
                                    frame.alpha,
                                    frame.uv,
                                ));
                            } else {
                                active = false;
                            }
                        } else {
                            vertices = Some(sprite_quad_vertices_pixels(
                                camera,
                                frame.direction,
                                (camera.far_plane * 0.5).max(camera.near_plane * 2.0),
                                half_width,
                                half_height,
                                viewport,
                                frame.color,
                                frame.alpha,
                                frame.uv,
                            ));
                        }
                    } else {
                        active = false;
                    }
                }
                material_alpha = if active {
                    // The packed sprite alpha is carried by the vertex. The
                    // MAT0 phase alpha remains the material multiplier;
                    // intensity controls lifecycle visibility, not a second
                    // alpha fade.
                    sprite.diffuse_alpha
                } else {
                    0.0
                };
            }
            if active {
                if let Some(vertices) = vertices {
                    let destination = mesh
                        .vertices
                        .get_mut(sprite.range.vertex_start..sprite.range.vertex_start + 4)
                        .ok_or_else(|| {
                            "sky sprite vertex allocation is out of bounds".to_string()
                        })?;
                    destination.copy_from_slice(&vertices);
                } else {
                    active = false;
                }
            }
            if sprite.flare_index.is_none() {
                let material_index = active_materials
                    .get(&sprite.range.range_index)
                    .map(|state| state.material_index)
                    .unwrap_or(sprite.material_index);
                // The animation update above has already restored the
                // sampled phase alpha for an active animated material.  A
                // hidden sprite still needs an explicit zero, while a static
                // sprite uses its authored material alpha when visible.
                let should_write_alpha =
                    !active || !active_materials.contains_key(&sprite.range.range_index);
                if should_write_alpha {
                    renderer
                        .set_material_alphas(material_index, material_alpha.clamp(0.0, 1.0), 0.0)
                        .map_err(|error| format!("update sky sprite alpha: {error}"))?;
                }
            }
            renderer
                .set_draw_range_index_count(sprite.range.range_index, if active { 6 } else { 0 })
                .map_err(|error| format!("update sky sprite draw range: {error}"))?;
        }

        let mut rain_count = 0usize;
        let mut snow_count = 0usize;
        let mut lightning = None;
        for primitive in &environment_frame.primitives {
            match primitive {
                EnvironmentPrimitive::Particle {
                    kind,
                    color,
                    screen,
                    ..
                } => {
                    let (range, slot) = match kind {
                        PrecipitationKind::Rain if rain_count < ENVIRONMENT_PARTICLE_SLOTS => {
                            let slot = rain_count;
                            rain_count += 1;
                            (self.rain, slot)
                        }
                        PrecipitationKind::Snow if snow_count < ENVIRONMENT_PARTICLE_SLOTS => {
                            let slot = snow_count;
                            snow_count += 1;
                            (self.snow, slot)
                        }
                        _ => continue,
                    };
                    let vertices =
                        precipitation_quad_vertices(*kind, screen, *color, camera, viewport);
                    let start = range.vertex_start + slot * 4;
                    let destination = mesh.vertices.get_mut(start..start + 4).ok_or_else(|| {
                        "precipitation vertex allocation is out of bounds".to_string()
                    })?;
                    destination.copy_from_slice(&vertices);
                }
                EnvironmentPrimitive::Lightning(bolt) if lightning.is_none() => {
                    lightning = Some(bolt);
                }
                EnvironmentPrimitive::Lightning(_) => {}
            }
        }
        renderer
            .set_draw_range_index_count(
                self.rain.range_index,
                u32::try_from(rain_count * 6)
                    .map_err(|_| "rain draw count exceeds u32".to_string())?,
            )
            .map_err(|error| format!("update rain draw range: {error}"))?;
        renderer
            .set_draw_range_index_count(
                self.snow.range_index,
                u32::try_from(snow_count * 6)
                    .map_err(|_| "snow draw count exceeds u32".to_string())?,
            )
            .map_err(|error| format!("update snow draw range: {error}"))?;

        let lightning_alpha = if let Some(bolt) = lightning {
            let vertices = lightning_quad_vertices(bolt);
            let destination = mesh
                .vertices
                .get_mut(self.lightning.vertex_start..self.lightning.vertex_start + 4)
                .ok_or_else(|| "lightning vertex allocation is out of bounds".to_string())?;
            destination.copy_from_slice(&vertices);
            bolt.intensity.clamp(0.0, 1.0)
        } else {
            0.0
        };
        let lightning_material_index = active_materials
            .get(&self.lightning.range_index)
            .map(|state| state.material_index)
            .unwrap_or(self.lightning_material_index);
        renderer
            .set_material_alphas(lightning_material_index, lightning_alpha, 0.0)
            .map_err(|error| format!("update lightning material alpha: {error}"))?;
        renderer
            .set_draw_range_index_count(
                self.lightning.range_index,
                if lightning.is_some() { 6 } else { 0 },
            )
            .map_err(|error| format!("update lightning draw range: {error}"))?;
        Ok(())
    }
}

fn sprite_frame_for_row<'frame, 'materials>(
    sky_frame: &'frame SkyFrame<'materials>,
    row: usize,
) -> Option<SkySpriteFrame<'materials>> {
    sky_frame
        .sprites
        .iter()
        .copied()
        .find(|sprite| sprite.row == row)
}

fn horizontal_fov(camera: &PreviewCameraFrame, aspect: f32) -> f32 {
    let aspect = if aspect.is_finite() && aspect > 0.0 {
        aspect
    } else {
        16.0 / 9.0
    };
    2.0 * ((camera.vertical_fov * 0.5).tan() * aspect).atan()
}

/// Tests the camera-to-sun segment against the validated mission terrain.
///
/// The native CSun caller starts a half-unit in front of the camera along the
/// normalized geometry direction, then queries the finite segment ending at
/// the sun center. Terrain source positions and captured-camera positions both
/// use the `Land.msh` coordinate units, so the ray is queried without a Z
/// conversion. Its parameter remains normalized to the finite segment and is
/// therefore independent of world distance.
#[cfg(test)]
fn native_sun_unoccluded(
    terrain: &TerrainWorld,
    camera: &PreviewCameraFrame,
    direction: [f32; 3],
) -> bool {
    let empty_mesh = VulkanStaticMesh {
        vertices: Vec::new(),
        indices: Vec::new(),
        draw_ranges: Vec::new(),
    };
    native_sun_unoccluded_with_world(terrain, &empty_mesh, &[], camera, direction)
}

fn native_sun_unoccluded_with_world(
    terrain: &TerrainWorld,
    world_mesh: &VulkanStaticMesh,
    sun_occlusion_range_indices: &[usize],
    camera: &PreviewCameraFrame,
    direction: [f32; 3],
) -> bool {
    // Native CSun requests object kinds 1, 3, 4, and 10 (the aggregate
    // object mask is 0x41A) and excludes full surface flag 0x20. The preview
    // range list is built from roots whose raw mission kind is one of those
    // four eligible kinds; fixed atmosphere ranges are remapped out before
    // this call.
    let Some(direction) = normalize3(direction) else {
        return false;
    };
    let sun_center = add3(
        camera.position,
        scale3(
            direction,
            (camera.far_plane * 0.5).max(camera.near_plane * 2.0),
        ),
    );
    let start = add3(camera.position, scale3(direction, 0.5));
    let segment = sub3(sun_center, start);
    if !sun_center
        .iter()
        .chain(start.iter())
        .chain(segment.iter())
        .all(|value| value.is_finite())
    {
        return false;
    }
    if dot3(segment, segment) <= f32::EPSILON {
        return true;
    }
    if let Ok(Some(hit)) = terrain.raycast_excluding(
        start,
        segment,
        FullSurfaceMask(0),
        FullSurfaceMask(0x0000_0020),
    ) {
        if hit.distance.is_finite() && hit.distance <= 1.0 {
            return false;
        }
    }
    !world_mesh_sun_occluded(world_mesh, sun_occlusion_range_indices, start, segment)
}

fn world_mesh_sun_occluded(
    mesh: &VulkanStaticMesh,
    range_indices: &[usize],
    origin: [f32; 3],
    direction: [f32; 3],
) -> bool {
    for &range_index in range_indices {
        let Some(range) = mesh.draw_ranges.get(range_index).copied() else {
            continue;
        };
        // The native world query receives the compact exclusion bit 0x8,
        // which is the world-space representation of full surface flag 0x20.
        if range.batch_flags & 0x0008 != 0 {
            continue;
        }
        let Ok(first_index) = usize::try_from(range.first_index) else {
            continue;
        };
        let Ok(index_count) = usize::try_from(range.index_count) else {
            continue;
        };
        let Some(indices) = mesh
            .indices
            .get(first_index..first_index.saturating_add(index_count))
        else {
            continue;
        };
        for triangle in indices.chunks_exact(3) {
            let Ok(a) = usize::try_from(triangle[0]) else {
                continue;
            };
            let Ok(b) = usize::try_from(triangle[1]) else {
                continue;
            };
            let Ok(c) = usize::try_from(triangle[2]) else {
                continue;
            };
            let (Some(&a), Some(&b), Some(&c)) = (
                mesh.vertices.get(a),
                mesh.vertices.get(b),
                mesh.vertices.get(c),
            ) else {
                continue;
            };
            if segment_intersects_triangle(origin, direction, a.position, b.position, c.position) {
                return true;
            }
        }
    }
    false
}

fn segment_intersects_triangle(
    origin: [f32; 3],
    direction: [f32; 3],
    a: [f32; 3],
    b: [f32; 3],
    c: [f32; 3],
) -> bool {
    let edge1 = sub3(b, a);
    let edge2 = sub3(c, a);
    let pvec = cross3(direction, edge2);
    let determinant = dot3(edge1, pvec);
    if !determinant.is_finite() || determinant.abs() <= f32::EPSILON {
        return false;
    }
    let inverse = determinant.recip();
    let tvec = sub3(origin, a);
    let u = dot3(tvec, pvec) * inverse;
    if !u.is_finite() || !(0.0..=1.0).contains(&u) {
        return false;
    }
    let qvec = cross3(tvec, edge1);
    let v = dot3(direction, qvec) * inverse;
    if !v.is_finite() || v < 0.0 || u + v > 1.0 {
        return false;
    }
    let distance = dot3(edge2, qvec) * inverse;
    distance.is_finite() && (0.0..=1.0).contains(&distance)
}

/// Replays Terrain's native packet callback: a draw range is keyed by the
/// camera distance to its first indexed vertex.
fn first_indexed_vertex_distance(
    mesh: &VulkanStaticMesh,
    range_index: usize,
    camera_position: [f32; 3],
) -> Result<f32, String> {
    let range: VulkanStaticDrawRange = *mesh
        .draw_ranges
        .get(range_index)
        .ok_or_else(|| "world draw range index is out of bounds".to_string())?;
    let first_index = usize::try_from(range.first_index)
        .map_err(|_| "world draw range first index is not addressable".to_string())?;
    let vertex_index =
        usize::try_from(*mesh.indices.get(first_index).ok_or_else(|| {
            "world draw range first index is outside the index buffer".to_string()
        })?)
        .map_err(|_| "world draw range vertex index is not addressable".to_string())?;
    let vertex = mesh
        .vertices
        .get(vertex_index)
        .ok_or_else(|| "world draw range vertex index is outside the vertex buffer".to_string())?;
    let delta = sub3(vertex.position, camera_position);
    let distance = dot3(delta, delta).sqrt();
    distance
        .is_finite()
        .then_some(distance)
        .ok_or_else(|| "world draw range sort distance is non-finite".to_string())
}

fn project_direction_pixels(
    camera: &PreviewCameraFrame,
    direction: [f32; 3],
    viewport: [f32; 2],
) -> Option<[f32; 2]> {
    let direction = normalize3(direction)?;
    let width = viewport[0];
    let height = viewport[1];
    if !width.is_finite() || !height.is_finite() || width <= 0.0 || height <= 0.0 {
        return None;
    }
    let depth = dot3(camera.forward(), direction);
    if !depth.is_finite() || depth <= 1.0e-4 {
        return None;
    }
    let aspect = width / height;
    let half_vertical = (camera.vertical_fov * 0.5).tan();
    let half_horizontal = half_vertical * aspect;
    let ndc_x = dot3(camera.right(), direction) / (depth * half_horizontal);
    let ndc_y = dot3(camera.up(), direction) / (depth * half_vertical);
    let pixels = [(ndc_x * 0.5 + 0.5) * width, (0.5 - ndc_y * 0.5) * height];
    pixels
        .iter()
        .all(|value| value.is_finite())
        .then_some(pixels)
}

fn screen_ray_from_pixels(
    camera: &PreviewCameraFrame,
    pixels: [f32; 2],
    viewport: [f32; 2],
) -> Option<[f32; 3]> {
    if !pixels.iter().all(|value| value.is_finite())
        || !viewport.iter().all(|value| value.is_finite())
        || viewport[0] <= 0.0
        || viewport[1] <= 0.0
    {
        return None;
    }
    let aspect = viewport[0] / viewport[1];
    let half_vertical = (camera.vertical_fov * 0.5).tan();
    let half_horizontal = half_vertical * aspect;
    let ndc_x = pixels[0] / viewport[0] * 2.0 - 1.0;
    let ndc_y = 1.0 - pixels[1] / viewport[1] * 2.0;
    normalize3(add3(
        add3(
            camera.forward(),
            scale3(camera.right(), ndc_x * half_horizontal),
        ),
        scale3(camera.up(), ndc_y * half_vertical),
    ))
}

fn sprite_quad_vertices_pixels(
    camera: &PreviewCameraFrame,
    direction: [f32; 3],
    distance: f32,
    half_width_pixels: f32,
    half_height_pixels: f32,
    viewport: [f32; 2],
    color: [f32; 3],
    alpha: f32,
    uv: [[f32; 2]; 4],
) -> [VulkanStaticVertex; 4] {
    let direction = normalize3(direction).unwrap_or(camera.forward());
    let center = add3(camera.position, scale3(direction, distance));
    let depth = dot3(camera.forward(), direction)
        .mul_add(distance, 0.0)
        .max(camera.near_plane.max(0.001));
    let width = viewport[0].max(1.0);
    let height = viewport[1].max(1.0);
    let aspect = width / height;
    let vertical_fov = camera.vertical_fov;
    let horizontal_fov_radians = horizontal_fov(camera, aspect);
    let world_per_pixel_x = 2.0 * depth * (horizontal_fov_radians * 0.5).tan() / width;
    let world_per_pixel_y = 2.0 * depth * (vertical_fov * 0.5).tan() / height;
    let right = scale3(
        camera.right(),
        half_width_pixels.max(0.0) * world_per_pixel_x,
    );
    let up = scale3(camera.up(), half_height_pixels.max(0.0) * world_per_pixel_y);
    // Native sun and flare UVs are ordered left-top, left-bottom, right-bottom,
    // right-top. The shared index order is bottom-left, bottom-right, top-left,
    // top-right.
    let uv = [uv[1], uv[2], uv[0], uv[3]];
    [
        environment_vertex_with_alpha(sub3(sub3(center, right), up), color, alpha, uv[0]),
        environment_vertex_with_alpha(add3(sub3(center, up), right), color, alpha, uv[1]),
        environment_vertex_with_alpha(add3(sub3(center, right), up), color, alpha, uv[2]),
        environment_vertex_with_alpha(add3(add3(center, right), up), color, alpha, uv[3]),
    ]
}

fn screen_tl_quad_vertices_pixels(
    center_pixels: [f32; 2],
    half_width_pixels: f32,
    half_height_pixels: f32,
    viewport: [f32; 2],
    color: [f32; 3],
    alpha: f32,
    uv: [[f32; 2]; 4],
) -> [VulkanStaticVertex; 4] {
    let width = viewport[0].max(1.0);
    let height = viewport[1].max(1.0);
    let half_width = half_width_pixels.max(0.0);
    let half_height = half_height_pixels.max(0.0);
    let pixel_corners = [
        [
            center_pixels[0] - half_width,
            center_pixels[1] + half_height,
        ],
        [
            center_pixels[0] + half_width,
            center_pixels[1] + half_height,
        ],
        [
            center_pixels[0] - half_width,
            center_pixels[1] - half_height,
        ],
        [
            center_pixels[0] + half_width,
            center_pixels[1] - half_height,
        ],
    ];
    // Positive-height Vulkan viewports map NDC -Y to top-down screen pixels.
    let uv = [uv[1], uv[2], uv[0], uv[3]];
    std::array::from_fn(|index| {
        let pixel = pixel_corners[index];
        let position = [
            pixel[0] * (2.0 / width) - 1.0,
            pixel[1] * (2.0 / height) - 1.0,
            0.999,
        ];
        environment_vertex_with_alpha(position, color, alpha, uv[index])
    })
}

fn precipitation_quad_vertices(
    kind: PrecipitationKind,
    screen: &ScreenBillboard,
    color: [f32; 4],
    camera: &PreviewCameraFrame,
    viewport: [f32; 2],
) -> [VulkanStaticVertex; 4] {
    let rgb = [color[0], color[1], color[2]];
    let depths = match kind {
        PrecipitationKind::Rain => [
            screen.tail_depth,
            screen.tail_depth,
            screen.head_depth,
            screen.head_depth,
        ],
        PrecipitationKind::Snow => [screen.head_depth; 4],
    };
    std::array::from_fn(|index| {
        environment_vertex_with_alpha(
            world_from_ndc(camera, screen.corners[index], depths[index], viewport),
            rgb,
            color[3],
            screen.uv[index],
        )
    })
}

fn world_from_ndc(
    camera: &PreviewCameraFrame,
    ndc: [f32; 2],
    depth: f32,
    viewport: [f32; 2],
) -> [f32; 3] {
    let depth = if depth.is_finite() {
        depth.max(camera.near_plane.max(0.001))
    } else {
        camera.near_plane.max(0.001)
    };
    let aspect = viewport[0].max(1.0) / viewport[1].max(1.0);
    let half_vertical = (camera.vertical_fov * 0.5).tan();
    let half_horizontal = half_vertical * aspect;
    let offset = add3(
        scale3(camera.right(), ndc[0] * half_horizontal),
        scale3(camera.up(), ndc[1] * half_vertical),
    );
    add3(
        camera.position,
        scale3(add3(camera.forward(), offset), depth),
    )
}

fn lightning_quad_vertices(
    bolt: &fparkan_fx::environment::LightningBolt,
) -> [VulkanStaticVertex; 4] {
    std::array::from_fn(|index| {
        environment_vertex(bolt.quad.vertices[index], [1.0; 3], bolt.quad.uv[index])
    })
}

/// CPU atmosphere state shared by the interactive preview and the renderer's
/// per-frame light/fog block.  The sky mesh and weather primitives stay on the
/// same update clock, so camera movement cannot leave environment audio or
/// lighting one frame behind.
struct DynamicEnvironment {
    schedule: TypedAtmosphere,
    sky: SkySystem,
    environment: EnvironmentSystem,
    materials: SkyMaterials,
    material_assets: HashMap<String, EnvironmentMaterialAsset>,
    schedule_offset_seconds: f32,
    time_seconds: f32,
    fixed_schedule_seconds: Option<f32>,
    fixed_phase_reported: bool,
}

struct DynamicEnvironmentFrame {
    atmosphere: AtmosphereFrame,
    sky_mesh: SkyMesh,
    environment_frame: EnvironmentFrame,
    absolute_time_seconds: f32,
}

fn environment_camera_for_preview(
    camera: &PreviewCameraFrame,
    aspect: f32,
    viewport: [f32; 2],
) -> FxCamera {
    FxCamera::with_projection(
        camera.position,
        camera.forward(),
        camera.right(),
        camera.up(),
        camera.vertical_fov,
        aspect,
    )
    .with_viewport(viewport)
}

struct SceneFrameUpdate {
    clock: FrameClockSample,
    camera: PreviewCameraFrame,
    viewport: [f32; 2],
    aspect: f32,
    control_point_lights: Vec<(VulkanPointLight, u32)>,
    control_vulkan_lights: Vec<VulkanPointLight>,
    effect_updates: Vec<AmbientEffectGeometryUpdate>,
    world_sort_keys: Vec<(usize, f32)>,
    ambient_sort_keys: Vec<(usize, f32)>,
    material_update: MaterialFrameUpdate,
    environment_material_update: Option<MaterialFrameUpdate>,
    environment: Option<DynamicEnvironmentFrame>,
}

impl DynamicEnvironment {
    fn update_cpu(
        &mut self,
        dt_seconds: f32,
        camera: &PreviewCameraFrame,
        aspect: f32,
        viewport: [f32; 2],
        mut audio: Option<&mut audio::GameAudio>,
    ) -> Result<DynamicEnvironmentFrame, String> {
        let dt_seconds = if dt_seconds.is_finite() {
            dt_seconds.max(0.0)
        } else {
            0.0
        };
        let (time_seconds, absolute_time_seconds) = environment_sample_time(
            self.time_seconds,
            self.schedule_offset_seconds,
            dt_seconds,
            self.fixed_schedule_seconds,
        );
        self.time_seconds = time_seconds;
        if let Some(seconds) = self.fixed_schedule_seconds {
            if !self.fixed_phase_reported {
                eprintln!(
                    "CAPTURE_PHASE_SAMPLE absolute_seconds={seconds:.6} schedule_frozen=true"
                );
                self.fixed_phase_reported = true;
            }
        }
        let atmosphere = self.schedule.sample(absolute_time_seconds);
        let mut sky_mesh = self.sky.mesh().clone();
        let sky_frame =
            SkyFrame::from_atmosphere(&atmosphere, &self.materials, absolute_time_seconds);
        sky_mesh.update_colors(&sky_frame.sky);
        if let Some(audio) = audio.as_mut() {
            let primary_rgb = if sky_frame.sun.active {
                sky_frame.sun.color
            } else if sky_frame.moon.active {
                sky_frame.moon.color
            } else {
                [0.0; 3]
            };
            audio
                .update_ambience(dt_seconds, primary_rgb)
                .map_err(|error| format!("update ambient variation: {error}"))?;
        }

        let fx_camera = environment_camera_for_preview(camera, aspect, viewport);
        let environment_frame = self.environment.update_atmosphere_with_materials(
            dt_seconds,
            &atmosphere,
            &self.materials,
            fx_camera,
        );
        if let Some(audio) = audio.as_mut() {
            for sound in &environment_frame.sounds {
                audio
                    .handle_sound_event(sound)
                    .map_err(|error| format!("play environment sound: {error}"))?;
            }
        }
        Ok(DynamicEnvironmentFrame {
            atmosphere,
            sky_mesh,
            environment_frame,
            absolute_time_seconds,
        })
    }
}

fn load_environment(
    root: &Path,
    mission: &str,
    atmosphere_seconds: Option<f32>,
    hold_schedule_phase: bool,
) -> Result<Option<DynamicEnvironment>, String> {
    let mission_dir = mission_asset_directory(root, mission)?;
    let Some(sky_path) = find_mission_file(&mission_dir, "sky.ske")? else {
        return Ok(None);
    };
    let sky_bytes = std::fs::read(&sky_path)
        .map_err(|error| format!("read atmosphere {}: {error}", sky_path.display()))?;
    let schedule = TypedAtmosphere::parse(&sky_bytes)
        .map_err(|error| format!("parse atmosphere {}: {error}", sky_path.display()))?;

    let sky_wea_path = match find_sibling_file(&sky_path, "sky.wea") {
        Some(path) => Some(path),
        None => find_mission_file(&mission_dir, "sky.wea")?,
    }
    .ok_or_else(|| format!("selected atmosphere {} has no sky.wea", sky_path.display()))?;
    let materials = SkyMaterials::parse(
        &std::fs::read(&sky_wea_path)
            .map_err(|error| format!("read sky materials {}: {error}", sky_wea_path.display()))?,
    )
    .map_err(|error| format!("parse sky materials {}: {error}", sky_wea_path.display()))?;
    let mut sky_material_loader = StandaloneWearMaterialLoader::new(root);
    let mut material_assets =
        load_standalone_wear_named_material_textures_rgba8_and_phases_with_documents_from_root(
            root,
            &sky_wea_path,
            0,
        )
        .map_err(|error| {
            format!(
                "resolve sky material WEAR {}: {error}",
                sky_wea_path.display()
            )
        })?
        .into_iter()
        .enumerate()
        .map(
            |(material_index, (name, mips, phase, document))| -> Result<_, String> {
                let initial_phase = phase;
                let mut phase_textures = Vec::with_capacity(document.phases.len());
                let mut phases = Vec::with_capacity(document.phases.len());
                for phase_index in 0..document.phases.len() {
                    let phase_index_u16 = u16::try_from(phase_index).unwrap_or(u16::MAX);
                    let (phase_mips, sampled_phase) = if phase_index == 0 {
                        (mips.clone(), initial_phase)
                    } else {
                        sky_material_loader
                            .load(
                                &sky_wea_path,
                                u16::try_from(material_index).unwrap_or(u16::MAX),
                                phase_index_u16,
                            )
                            .map_err(|error| {
                                format!("resolve sky material phase {phase_index}: {error}")
                            })?
                    };
                    phase_textures.push(vulkan_texture_from_rgba_mips(phase_mips, "sky material")?);
                    phases.push(sampled_phase);
                }
                let texture = phase_textures
                    .first()
                    .cloned()
                    .ok_or_else(|| "sky material has no MAT0 phases".to_string())?;
                Ok((
                    String::from_utf8_lossy(&name).into_owned(),
                    EnvironmentMaterialAsset {
                        texture,
                        phase: initial_phase,
                        document,
                        phase_textures,
                        phases,
                    },
                ))
            },
        )
        .collect::<Result<HashMap<_, _>, String>>()?;
    let effect_bytes = load_resource_entry_bytes_from_root(root, "effects.rlb", "env_lightning")
        .map_err(|error| format!("load effects.rlb/env_lightning: {error}"))?;
    let lightning_effect = decode_env_lightning_fxid(effect_bytes)
        .map_err(|error| format!("decode effects.rlb/env_lightning: {error}"))?;
    if !lightning_effect
        .visual
        .archive
        .eq_ignore_ascii_case("material.lib")
    {
        return Err(format!(
            "env_lightning visual archive must be material.lib, got {:?}",
            lightning_effect.visual.archive
        ));
    }
    let (lightning_mips, lightning_phase, lightning_document) =
        load_material_name_texture_rgba8_and_phase_with_document_from_root(
            root,
            &lightning_effect.visual.name,
            0,
        )
        .map_err(|error| {
            format!(
                "resolve env_lightning MAT0 {}: {error}",
                lightning_effect.visual.name
            )
        })?;
    let mut lightning_phase_textures = vec![vulkan_texture_from_rgba_mips(
        lightning_mips,
        "env_lightning material",
    )?];
    let mut lightning_phases = vec![lightning_phase];
    for phase_index in 1..lightning_document.phases.len() {
        let (phase_mips, phase, _document) =
            load_material_name_texture_rgba8_and_phase_with_document_from_root(
                root,
                &lightning_effect.visual.name,
                u16::try_from(phase_index).unwrap_or(u16::MAX),
            )
            .map_err(|error| {
                format!(
                    "resolve env_lightning MAT0 phase {phase_index} {}: {error}",
                    lightning_effect.visual.name
                )
            })?;
        lightning_phase_textures.push(vulkan_texture_from_rgba_mips(
            phase_mips,
            "env_lightning material",
        )?);
        lightning_phases.push(phase);
    }
    let lightning_texture = lightning_phase_textures
        .first()
        .cloned()
        .ok_or_else(|| "env_lightning MAT0 has no phases".to_string())?;
    material_assets.insert(
        lightning_effect.visual.name.clone(),
        EnvironmentMaterialAsset {
            texture: lightning_texture,
            phase: lightning_phase,
            document: lightning_document,
            phase_textures: lightning_phase_textures,
            phases: lightning_phases,
        },
    );
    let initial_offset_seconds = schedule.initial_offset_seconds() as f32;
    let sky = SkySystem::new(Default::default(), materials.clone())
        .map_err(|error| format!("build sky geometry: {error}"))?;
    let time_seconds = atmosphere_seconds
        .map(|seconds| seconds - initial_offset_seconds)
        .unwrap_or(0.0);
    let fixed_schedule_seconds = if hold_schedule_phase {
        atmosphere_seconds
    } else {
        None
    };
    let mut environment = EnvironmentSystem::new(0x4650_4152_4B41_4E_u64);
    environment.set_lightning_effect(lightning_effect);
    Ok(Some(DynamicEnvironment {
        schedule,
        sky,
        environment,
        materials,
        material_assets,
        schedule_offset_seconds: initial_offset_seconds,
        time_seconds,
        fixed_schedule_seconds,
        fixed_phase_reported: false,
    }))
}

fn environment_sample_time(
    time_seconds: f32,
    schedule_offset_seconds: f32,
    dt_seconds: f32,
    fixed_schedule_seconds: Option<f32>,
) -> (f32, f32) {
    if let Some(absolute_seconds) = fixed_schedule_seconds {
        return (time_seconds, absolute_seconds);
    }

    let next_time_seconds = if time_seconds.is_finite() {
        time_seconds + dt_seconds
    } else {
        0.0
    };
    (
        next_time_seconds,
        schedule_offset_seconds + next_time_seconds,
    )
}

/// Returns the host directory containing the selected mission's assets.
/// Mission keys are the same relative paths accepted by the runtime VFS; the
/// host root is only used here for the small set of loose mission-local files
/// that are not archive entries (`sky.ske` and `sky.wea`).
fn mission_asset_directory(root: &Path, mission: &str) -> Result<PathBuf, String> {
    let mission_path = Path::new(mission);
    if mission_path.is_absolute() {
        return Err("mission environment path must be relative to --root".to_string());
    }
    let directory = mission_path
        .parent()
        .filter(|parent| !parent.as_os_str().is_empty())
        .unwrap_or_else(|| Path::new("."));
    let directory = root.join(directory);
    if !directory.is_dir() {
        return Err(format!(
            "selected mission asset directory does not exist: {}",
            directory.display()
        ));
    }
    Ok(directory)
}

/// Finds one mission-local loose environment file.  A direct sibling wins;
/// nested `env`, `environment`, or `planet` layouts are accepted only when
/// they contain a single matching file, so a second unrelated candidate never
/// changes the selected mission silently.
fn find_mission_file(root: &Path, name: &str) -> Result<Option<PathBuf>, String> {
    let direct = root.join(name);
    if direct.is_file() {
        return Ok(Some(direct));
    }
    let mut stack = vec![root.to_path_buf()];
    let mut matches = Vec::new();
    while let Some(directory) = stack.pop() {
        let Ok(entries) = std::fs::read_dir(&directory) else {
            continue;
        };
        for entry in entries.flatten() {
            let path = entry.path();
            let Ok(file_type) = entry.file_type() else {
                continue;
            };
            if file_type.is_symlink() {
                continue;
            }
            if file_type.is_dir() {
                stack.push(path);
            } else if file_type.is_file()
                && path
                    .file_name()
                    .is_some_and(|file_name| file_name.eq_ignore_ascii_case(name))
            {
                matches.push(path);
            }
        }
    }
    matches.sort();
    match matches.as_slice() {
        [] => Ok(None),
        [path] => Ok(Some(path.clone())),
        _ => Err(format!(
            "selected mission has multiple {name} files: {}",
            matches
                .iter()
                .map(|path| path.display().to_string())
                .collect::<Vec<_>>()
                .join(", ")
        )),
    }
}

fn find_sibling_file(source: &Path, name: &str) -> Option<PathBuf> {
    source
        .parent()
        .map(|parent| parent.join(name))
        .filter(|path| path.is_file())
}

fn add3(left: [f32; 3], right: [f32; 3]) -> [f32; 3] {
    [left[0] + right[0], left[1] + right[1], left[2] + right[2]]
}

fn add3_in_place(target: &mut [f32; 3], value: [f32; 3]) {
    *target = add3(*target, value);
}

fn sub3(left: [f32; 3], right: [f32; 3]) -> [f32; 3] {
    [left[0] - right[0], left[1] - right[1], left[2] - right[2]]
}

fn scale3(value: [f32; 3], factor: f32) -> [f32; 3] {
    [value[0] * factor, value[1] * factor, value[2] * factor]
}

fn multiply3(left: [f32; 3], right: [f32; 3]) -> [f32; 3] {
    [left[0] * right[0], left[1] * right[1], left[2] * right[2]]
}

fn dot3(left: [f32; 3], right: [f32; 3]) -> f32 {
    left[0].mul_add(right[0], left[1].mul_add(right[1], left[2] * right[2]))
}

fn cross3(left: [f32; 3], right: [f32; 3]) -> [f32; 3] {
    [
        left[1] * right[2] - left[2] * right[1],
        left[2] * right[0] - left[0] * right[2],
        left[0] * right[1] - left[1] * right[0],
    ]
}

fn length3(value: [f32; 3]) -> Option<f32> {
    let length = dot3(value, value).sqrt();
    length
        .is_finite()
        .then_some(length)
        .filter(|length| *length > f32::EPSILON)
}

fn normalize3(value: [f32; 3]) -> Option<[f32; 3]> {
    let inverse = length3(value)?.recip();
    Some(scale3(value, inverse))
}

fn multiply_row_major(left: [f32; 16], right: [f32; 16]) -> [f32; 16] {
    let mut result = [0.0; 16];
    for row in 0..4 {
        for column in 0..4 {
            result[row * 4 + column] = (0..4)
                .map(|inner| left[row * 4 + inner] * right[inner * 4 + column])
                .sum();
        }
    }
    result
}

struct StaticPreviewScene {
    mesh: VulkanStaticMesh,
    native_handedness_by_range: HashMap<usize, i8>,
    type16_present_ranges: HashSet<usize>,
    materials: Vec<VulkanStaticMaterial>,
    material_animations: Vec<MaterialAnimationBinding>,
    ambient_effect_slots: Vec<AmbientEffectGpuSlot>,
    control_point_light_slots: Vec<ControlPointLightSlot>,
    component_pose_buffers: Vec<Vec<Option<NodePoseBuffer>>>,
    component_mount_poses: Vec<Vec<Option<VulkanNodePose>>>,
    dynamic_component_geometry: Vec<Vec<Option<DynamicComponentGeometry>>>,
    building_collision_bindings: Vec<BuildingCollisionBinding>,
    control_animation_instances: Vec<Vec<Option<ControlAnimationInstance>>>,
    dynamic_shadow_casters: Vec<DynamicShadowCaster>,
    sun_occlusion_range_indices: Vec<usize>,
    shadow_casters: Vec<ShadowCaster>,
    shadow_receivers: Vec<ShadowTriangle>,
    shadow_material_index: usize,
    terrain: Arc<TerrainWorld>,
    camera: VulkanStaticCamera,
    view_camera: PreviewCameraFrame,
    captured_viewport: Option<CapturedViewport>,
    free_camera: Option<FreeFlightCamera>,
    camera_mode: &'static str,
    mesh_components: usize,
    terrain_components: usize,
}

#[derive(Clone)]
struct ControlAnimationInstance {
    control: PreparedComponentControl,
    model: ModelAsset,
    gate_values: Vec<Option<f32>>,
    state: ControlInstanceState,
    last_sampled_node_times: Vec<Option<f32>>,
    reported_unsupported_fallback: bool,
}

#[derive(Clone)]
struct DynamicComponentGeometry {
    model: ModelAsset,
    root_transform: LegacyIron3dEulerTransform,
    owner_scale: [f32; 3],
    parent_mount: Option<(usize, usize)>,
    vertex_start: usize,
    vertex_count: usize,
}

#[derive(Clone)]
struct BuildingCollisionBinding {
    object_index: usize,
    component_index: usize,
    model_source: String,
    model: Arc<ModelAsset>,
    root_transform: LegacyIron3dEulerTransform,
    owner_scale: [f32; 3],
    mounted: bool,
    selected_nodes: Vec<(NodeId, SlotId)>,
}

fn building_collision_binding(
    object_index: usize,
    component_index: usize,
    model_source: String,
    model: Arc<ModelAsset>,
    root_transform: LegacyIron3dEulerTransform,
    owner_scale: [f32; 3],
    mounted: bool,
) -> Result<BuildingCollisionBinding, String> {
    let context = || {
        format!(
            "building collision object {object_index} component {component_index} model {model_source}"
        )
    };
    if model.node_stride != 38 || model.node_count == 0 || model.animation.is_none() {
        return Err(format!("{} has no complete Node38 pose data", context()));
    }
    if model.triangle_descriptors.is_none() {
        return Err(format!("{} has no type-7 collision descriptors", context()));
    }
    if root_transform.try_row_major().is_none()
        || !owner_scale.iter().all(|value| value.is_finite())
        || owner_scale.contains(&0.0)
    {
        return Err(format!("{} has an invalid world transform", context()));
    }
    let first_node = usize::from(mounted);
    let mut selected_nodes = Vec::new();
    for node_index in first_node..model.node_count {
        let node = NodeId(
            u32::try_from(node_index)
                .map_err(|_| format!("{} node index exceeds u32", context()))?,
        );
        let Some(slot) = selected_slot(&model, node, Lod(0), Group(0)) else {
            continue;
        };
        let slot_index = usize::try_from(slot.0)
            .map_err(|_| format!("{} node {} has an invalid slot id", context(), node.0))?;
        let slot_data = model.slots.get(slot_index).ok_or_else(|| {
            format!(
                "{} node {} selects missing slot {}",
                context(),
                node.0,
                slot.0
            )
        })?;
        let batch_start = usize::from(slot_data.batch_start);
        let batch_end = batch_start
            .checked_add(usize::from(slot_data.batch_count))
            .ok_or_else(|| format!("{} node {} batch range overflows", context(), node.0))?;
        let batches = model.batches.get(batch_start..batch_end).ok_or_else(|| {
            format!(
                "{} node {} batch range {batch_start}..{batch_end} is invalid",
                context(),
                node.0
            )
        })?;
        if batches.iter().any(|batch| batch.index_count != 0) {
            selected_nodes.push((node, slot));
        }
    }
    Ok(BuildingCollisionBinding {
        object_index,
        component_index,
        model_source,
        model,
        root_transform,
        owner_scale,
        mounted,
        selected_nodes,
    })
}

fn building_collision_nodes(
    binding: &BuildingCollisionBinding,
    pose_buffer: Option<&NodePoseBuffer>,
    mount_pose: Option<VulkanNodePose>,
) -> Result<Vec<BuildingMeshNode>, String> {
    let context = || {
        format!(
            "building collision object {} component {} model {}",
            binding.object_index, binding.component_index, binding.model_source
        )
    };
    if binding.mounted != mount_pose.is_some() {
        return Err(format!(
            "{} has {} mount pose, expected {}",
            context(),
            if mount_pose.is_some() { "a" } else { "no" },
            if binding.mounted { "a" } else { "no" }
        ));
    }
    binding
        .selected_nodes
        .iter()
        .map(|(node, slot)| {
            let node_index =
                usize::try_from(node.0).map_err(|_| format!("{} node id is invalid", context()))?;
            let pose = match (pose_buffer, binding.mounted) {
                (Some(hierarchy), true) => {
                    node38_pose_relative_to_root_from_hierarchy(hierarchy, node_index)
                }
                (Some(hierarchy), false) => node38_pose_from_hierarchy(hierarchy, node_index),
                (None, true) => node38_pose_relative_to_root(&binding.model, None, node_index),
                (None, false) => node38_pose(&binding.model, None, node_index),
            }
            .ok_or_else(|| format!("{} node {} has no current Node38 pose", context(), node.0))?;
            let world_from_node = component_node_world_matrix(
                binding.root_transform,
                binding.owner_scale,
                mount_pose,
                pose,
            )
            .ok_or_else(|| format!("{} node {} has an invalid world matrix", context(), node.0))?;
            Ok(BuildingMeshNode {
                node: *node,
                slot: *slot,
                world_from_node,
            })
        })
        .collect()
}

fn component_node_world_matrix(
    root_transform: LegacyIron3dEulerTransform,
    owner_scale: [f32; 3],
    mount_pose: Option<VulkanNodePose>,
    node_pose: VulkanNodePose,
) -> Option<[f32; 16]> {
    if !owner_scale
        .iter()
        .chain(node_pose.translation.iter())
        .chain(node_pose.rotation.iter())
        .chain(mount_pose.iter().flat_map(|pose| pose.translation.iter()))
        .chain(mount_pose.iter().flat_map(|pose| pose.rotation.iter()))
        .all(|value| value.is_finite())
    {
        return None;
    }
    let pose_matrix = |pose: VulkanNodePose| {
        let [x, y, z] = [
            rotate_unit_vector([1.0, 0.0, 0.0], pose.rotation),
            rotate_unit_vector([0.0, 1.0, 0.0], pose.rotation),
            rotate_unit_vector([0.0, 0.0, 1.0], pose.rotation),
        ];
        [
            x[0],
            y[0],
            z[0],
            pose.translation[0],
            x[1],
            y[1],
            z[1],
            pose.translation[1],
            x[2],
            y[2],
            z[2],
            pose.translation[2],
            0.0,
            0.0,
            0.0,
            1.0,
        ]
    };
    let scale = [
        owner_scale[0],
        0.0,
        0.0,
        0.0,
        0.0,
        owner_scale[1],
        0.0,
        0.0,
        0.0,
        0.0,
        owner_scale[2],
        0.0,
        0.0,
        0.0,
        0.0,
        1.0,
    ];
    let mut world = multiply_row_major(root_transform.try_row_major()?, scale);
    if let Some(mount) = mount_pose {
        world = multiply_row_major(world, pose_matrix(mount));
    }
    world = multiply_row_major(world, pose_matrix(node_pose));
    world.iter().all(|value| value.is_finite()).then_some(world)
}

#[derive(Clone, Debug)]
struct DynamicShadowCaster {
    caster_index: usize,
    object_index: usize,
    root_transform: LegacyIron3dEulerTransform,
    owner_scale: [f32; 3],
    initial_sphere: ShadowSphere,
    component_draw_range_indices: Vec<usize>,
    component_spheres: Vec<DynamicShadowSphereSource>,
}

#[derive(Clone, Copy, Debug)]
struct DynamicShadowSphereSource {
    component_index: usize,
    center: [f32; 3],
    radius: f32,
    mounted: bool,
}

#[derive(Clone, Copy, Debug, PartialEq)]
struct CapturedViewport {
    /// Original D3D7 viewport rectangle `(left, top, right, bottom)`. The
    /// preview window renders `extent` and should be compared with this crop.
    rect: [i32; 4],
    extent: [u32; 2],
}

fn validate_captured_drawable_extent(
    captured: CapturedViewport,
    actual: [u32; 2],
) -> Result<(), String> {
    if actual == captured.extent {
        return Ok(());
    }
    Err(format!(
        "legacy camera viewport crop {:?} requires a {}x{} drawable, but the window provides {}x{}; refusing to compare a stretched render",
        captured.rect, captured.extent[0], captured.extent[1], actual[0], actual[1]
    ))
}

#[derive(Clone, Copy, Debug, Default)]
struct StartupTimings {
    mission_assets: Duration,
    terrain_materials: Duration,
    sky: Duration,
    gpu_initialization: Duration,
}

#[derive(Clone, Copy, Debug, Default)]
struct ShadowFrameEvidence {
    visible_casters: usize,
    projected_indices: usize,
}

fn elapsed_ms(duration: Duration) -> f64 {
    duration.as_secs_f64() * 1_000.0
}

fn unit_component_is_visible(index: usize, source_type: Option<u32>) -> bool {
    index == 0 || source_type == Some(PROTOTYPE_TYPE_EXTO)
}

fn native_sun_object_kind_eligible(source_type: Option<u32>) -> bool {
    native_shadow_kind(source_type).is_some()
}

const PROTOTYPE_TYPE_FORT: u32 = u32::from_le_bytes(*b"FORT");
const PROTOTYPE_TYPE_BTLU: u32 = u32::from_le_bytes(*b"BTLU");
const PROTOTYPE_TYPE_STAT: u32 = u32::from_le_bytes(*b"STAT");

// shortcut: the preview does not load shade.cfg yet, so use CShade's native
// defaults until the settings loader is implemented.
const NATIVE_DEFAULT_ROB_SHADOWS_ON: bool = true;
const NATIVE_DEFAULT_BLD_SHADOWS_ON: bool = false;

/// Maps the resolved registry type to the native object-kind selector used by
/// CSun/CShade.  The mission object's raw kind is an unrelated TMA field; the
/// renderer receives the registry provenance from the prepared visual.
fn native_shadow_kind(source_type: Option<u32>) -> Option<u32> {
    match source_type {
        Some(PROTOTYPE_TYPE_FORT) => Some(3),
        Some(PROTOTYPE_TYPE_BTLU) => Some(4),
        Some(PROTOTYPE_TYPE_STAT) => Some(10),
        _ => None,
    }
}

fn native_shadow_caster_enabled(native_kind: u32) -> bool {
    if native_kind == 4 {
        NATIVE_DEFAULT_ROB_SHADOWS_ON
    } else {
        NATIVE_DEFAULT_BLD_SHADOWS_ON
    }
}

fn compose_unit_pose(parent: VulkanNodePose, child: VulkanNodePose) -> VulkanNodePose {
    let rotated = rotate_unit_vector(child.translation, parent.rotation);
    VulkanNodePose {
        translation: [
            parent.translation[0] + rotated[0],
            parent.translation[1] + rotated[1],
            parent.translation[2] + rotated[2],
        ],
        rotation: multiply_unit_quaternions(parent.rotation, child.rotation),
    }
}

fn control_type4_local_matrix(
    points: [&PreparedControlPoint; 3],
    owner_scale: [f32; 3],
) -> Option<[[f32; 4]; 4]> {
    if !owner_scale.iter().all(|value| value.is_finite()) {
        return None;
    }
    let positions = points.map(|point| multiply3(point.position, owner_scale));
    let directions = points.map(|point| multiply3(point.direction, owner_scale));
    if !positions
        .iter()
        .flatten()
        .chain(directions.iter().flatten())
        .all(|value| value.is_finite())
    {
        return None;
    }
    let reciprocal_three = f32::from_bits(0x3EAA_AAAB);
    let translation = std::array::from_fn(|axis| {
        (positions[0][axis] + positions[1][axis] + positions[2][axis]) * reciprocal_three
    });
    if !translation.iter().all(|value| value.is_finite()) {
        return None;
    }

    let [d0, d1, d2] = directions;
    if d0 == d1 && d1 == d2 {
        let magnitude = finite_length3(d0)?;
        if magnitude <= 0.0 {
            return None;
        }
        let basis = control_3ef0_basis(scale3(d0, magnitude.recip()), translation)?;
        let scaled = std::array::from_fn(|row| {
            let mut result = basis[row];
            for column in 0..3 {
                result[column] *= magnitude;
            }
            result
        });
        return scaled
            .iter()
            .flatten()
            .all(|value| value.is_finite())
            .then_some(scaled);
    }
    let (s, a) = if d0 == d2 || d1 == d2 {
        (d0, d1)
    } else if d0 == d1 {
        (d0, d2)
    } else {
        let matrix = control_matrix_from_columns(d0, d1, d2, translation);
        return matrix
            .iter()
            .flatten()
            .all(|value| value.is_finite())
            .then_some(matrix);
    };

    // In a repeated-direction row d0 is always the native S vector; the
    // other vector selected above is A for helper 0x4070.
    let cross = cross3(a, s);
    let cross_length = finite_length3(cross)?;
    if cross_length <= 0.0 {
        return control_3ef0_basis(s, translation);
    }
    let u = scale3(cross, cross_length.recip());
    let v = cross3(s, u);
    let matrix = control_matrix_from_columns(s, u, v, translation);
    matrix
        .iter()
        .flatten()
        .all(|value| value.is_finite())
        .then_some(matrix)
}

fn control_3ef0_basis(axis: [f32; 3], translation: [f32; 3]) -> Option<[[f32; 4]; 4]> {
    if !axis
        .iter()
        .chain(translation.iter())
        .all(|value| value.is_finite())
    {
        return None;
    }
    let mut u = if axis[0] == 0.0 {
        [1.0, 0.0, 0.0]
    } else if axis[1] == 0.0 {
        [0.0, 1.0, 0.0]
    } else {
        [-axis[1], axis[0], 0.0]
    };
    if axis[2] != 0.0 {
        let u_length = finite_length3(u)?;
        if u_length <= 0.0 {
            return None;
        }
        u = scale3(u, u_length.recip());
    }
    let v = cross3(axis, u);
    let matrix = control_matrix_from_columns(axis, u, v, translation);
    matrix
        .iter()
        .flatten()
        .all(|value| value.is_finite())
        .then_some(matrix)
}

fn control_matrix_from_columns(
    first: [f32; 3],
    second: [f32; 3],
    third: [f32; 3],
    translation: [f32; 3],
) -> [[f32; 4]; 4] {
    [
        [first[0], second[0], third[0], translation[0]],
        [first[1], second[1], third[1], translation[1]],
        [first[2], second[2], third[2], translation[2]],
        [0.0, 0.0, 0.0, 1.0],
    ]
}

fn finite_length3(value: [f32; 3]) -> Option<f32> {
    let length = dot3(value, value).sqrt();
    length.is_finite().then_some(length)
}

fn control_type4_effect_local_matrix(
    points: [&PreparedControlPoint; 3],
    effect_scale: [f32; 3],
) -> Option<[[f32; 4]; 4]> {
    if !effect_scale.iter().all(|value| value.is_finite()) {
        return None;
    }
    let mut local = control_type4_local_matrix(points, [1.0; 3])?;
    for (column, scale) in effect_scale.into_iter().enumerate() {
        for row in &mut local[..3] {
            row[column] *= scale;
        }
    }
    local
        .iter()
        .flatten()
        .all(|value| value.is_finite())
        .then_some(local)
}

fn control_effect_owner_node_pose(
    hierarchy: Option<&NodePoseBuffer>,
    component_is_mounted: bool,
    owner_node_index: usize,
) -> Option<VulkanNodePose> {
    match hierarchy {
        Some(hierarchy) if component_is_mounted => {
            node38_pose_relative_to_root_from_hierarchy(hierarchy, owner_node_index)
        }
        Some(hierarchy) => node38_pose_from_hierarchy(hierarchy, owner_node_index),
        None if owner_node_index == 0 => Some(VulkanNodePose {
            translation: [0.0; 3],
            rotation: [0.0, 0.0, 0.0, 1.0],
        }),
        None => None,
    }
}

fn node_pose_row_major(pose: VulkanNodePose) -> [[f32; 4]; 4] {
    let basis = [
        rotate_unit_vector([1.0, 0.0, 0.0], pose.rotation),
        rotate_unit_vector([0.0, 1.0, 0.0], pose.rotation),
        rotate_unit_vector([0.0, 0.0, 1.0], pose.rotation),
    ];
    control_matrix_from_columns(basis[0], basis[1], basis[2], pose.translation)
}

fn component_mount_matrix(mount_pose: VulkanNodePose) -> [[f32; 4]; 4] {
    node_pose_row_major(mount_pose)
}

fn component_scale_matrix(scale: [f32; 3]) -> [[f32; 4]; 4] {
    [
        [scale[0], 0.0, 0.0, 0.0],
        [0.0, scale[1], 0.0, 0.0],
        [0.0, 0.0, scale[2], 0.0],
        [0.0, 0.0, 0.0, 1.0],
    ]
}

fn matrix_to_row_major(matrix: [[f32; 4]; 4]) -> [f32; 16] {
    std::array::from_fn(|index| matrix[index / 4][index % 4])
}

fn control_type4_world_from_effect(
    local_from_effect: [[f32; 4]; 4],
    owner_scale: [f32; 3],
    root_transform: LegacyIron3dEulerTransform,
    mount_pose: Option<VulkanNodePose>,
    owner_node_pose: VulkanNodePose,
) -> Option<[[f32; 4]; 4]> {
    if !owner_scale
        .iter()
        .chain(local_from_effect.iter().flatten())
        .chain(owner_node_pose.translation.iter())
        .chain(owner_node_pose.rotation.iter())
        .all(|value| value.is_finite())
    {
        return None;
    }
    let root = root_transform.try_row_major()?;
    let mut world_flat = multiply_row_major(
        root,
        matrix_to_row_major(component_scale_matrix(owner_scale)),
    );
    if let Some(mount) = mount_pose {
        world_flat = multiply_row_major(
            world_flat,
            matrix_to_row_major(component_mount_matrix(mount)),
        );
    }
    world_flat = multiply_row_major(
        world_flat,
        matrix_to_row_major(node_pose_row_major(owner_node_pose)),
    );
    world_flat = multiply_row_major(world_flat, matrix_to_row_major(local_from_effect));
    let world =
        std::array::from_fn(|row| std::array::from_fn(|column| world_flat[row * 4 + column]));
    world
        .iter()
        .flatten()
        .all(|value| value.is_finite())
        .then_some(world)
}

fn control_type4_world_from_effect_with_random_shift(
    mut local_from_effect: [[f32; 4]; 4],
    random_shift: [f32; 3],
    owner_scale: [f32; 3],
    root_transform: LegacyIron3dEulerTransform,
    mount_pose: Option<VulkanNodePose>,
    owner_node_pose: VulkanNodePose,
) -> Option<[[f32; 4]; 4]> {
    for (axis, value) in random_shift.into_iter().enumerate() {
        local_from_effect[axis][3] += value;
    }
    control_type4_world_from_effect(
        local_from_effect,
        owner_scale,
        root_transform,
        mount_pose,
        owner_node_pose,
    )
}

#[cfg(test)]
fn ambient_effect_world_from_component_pose(
    slot: &AmbientEffectGpuSlot,
    component_pose_buffers: &[Vec<Option<NodePoseBuffer>>],
) -> Option<[[f32; 4]; 4]> {
    ambient_effect_world_from_component_pose_with_random_shift(
        slot,
        component_pose_buffers,
        [0.0; 3],
    )
}

fn ambient_effect_world_from_component_pose_with_random_shift(
    slot: &AmbientEffectGpuSlot,
    component_pose_buffers: &[Vec<Option<NodePoseBuffer>>],
    random_shift: [f32; 3],
) -> Option<[[f32; 4]; 4]> {
    let hierarchy = component_pose_buffers
        .get(slot.owner_object_index)
        .and_then(|components| components.get(slot.owner_component_index))
        .and_then(Option::as_ref);
    let owner_node_pose = control_effect_owner_node_pose(
        hierarchy,
        slot.owner_component_is_mounted,
        slot.owner_node_index,
    )?;
    control_type4_world_from_effect_with_random_shift(
        slot.local_from_effect,
        random_shift,
        slot.owner_scale,
        slot.root_transform,
        slot.mount_pose,
        owner_node_pose,
    )
}

fn control_point_light_world_from_component_pose_with_random_shift(
    slot: &ControlPointLightSlot,
    component_pose_buffers: &[Vec<Option<NodePoseBuffer>>],
    random_shift: [f32; 3],
) -> Option<[[f32; 4]; 4]> {
    let hierarchy = component_pose_buffers
        .get(slot.owner_object_index)
        .and_then(|components| components.get(slot.owner_component_index))
        .and_then(Option::as_ref);
    let owner_node_pose = control_effect_owner_node_pose(
        hierarchy,
        slot.owner_component_is_mounted,
        slot.owner_node_index,
    )?;
    control_type4_world_from_effect_with_random_shift(
        slot.local_from_effect,
        random_shift,
        slot.owner_scale,
        slot.root_transform,
        slot.mount_pose,
        owner_node_pose,
    )
}

fn update_control_point_lights(
    slots: &mut [ControlPointLightSlot],
    component_pose_buffers: &[Vec<Option<NodePoseBuffer>>],
    component_mount_poses: &[Vec<Option<VulkanNodePose>>],
    elapsed_seconds: f32,
    random_samples: &HashMap<ControlEffectInstanceKey, ControlEffectRandomSample>,
    emit_diagnostic: bool,
) -> Vec<(VulkanPointLight, u32)> {
    let mut lights = Vec::new();
    for slot in slots {
        if slot.owner_component_is_mounted {
            slot.mount_pose = component_mount_poses
                .get(slot.owner_object_index)
                .and_then(|components| components.get(slot.owner_component_index))
                .copied()
                .flatten();
        }
        let random_sample = random_samples
            .get(&slot.random_instance_key)
            .copied()
            .unwrap_or_default();
        let Some(world_from_effect) =
            control_point_light_world_from_component_pose_with_random_shift(
                slot,
                component_pose_buffers,
                random_sample.accumulated_shift,
            )
        else {
            continue;
        };
        slot.world_from_effect = world_from_effect;
        let Some(phase) = ambient_effect_phase(
            slot.time_mode,
            slot.header_flags,
            elapsed_seconds,
            slot.duration_seconds,
        )
        .map(|phase| native_command_phase(slot.header_flags, phase, random_sample.phase_jitter)) else {
            continue;
        };
        let matrix = slot.world_from_effect;
        let origin = [matrix[0][3], matrix[1][3], matrix[2][3]];
        let basis = [
            [matrix[0][0], matrix[1][0], matrix[2][0]],
            [matrix[0][1], matrix[1][1], matrix[2][1]],
            [matrix[0][2], matrix[1][2], matrix[2][2]],
        ];
        let Some(frame) = evaluate_op1_point_light_with_basis(&slot.command, phase, origin, basis)
        else {
            continue;
        };
        if !frame.active || frame.light_selector != 1 {
            continue;
        }
        if emit_diagnostic {
            eprintln!(
                "control_point_light_detail object={} component={} table={} row={} command={} header_flags=0x{:08X} effect_type={} native_flags=0x{:08X} selector={} command_time={} phase={:.4} local_position_start={:?} local_position_end={:?} world_origin={:?} output_position={:?} rgb={:?} alpha={:.3} range={} attenuation={:?} effect_factor={}",
                slot.owner_object_index,
                slot.owner_component_index,
                slot.random_instance_key.table_index,
                slot.random_instance_key.row_index,
                slot.command_index,
                slot.header_flags,
                frame.effect_type,
                frame.native_flags,
                frame.light_selector,
                frame.command_time,
                phase,
                fx_command_vec3(&slot.command, 12),
                fx_command_vec3(&slot.command, 24),
                [matrix[0][3], matrix[1][3], matrix[2][3]],
                frame.position,
                frame.color,
                frame.color[3],
                frame.range,
                frame.attenuation,
                frame.effect_factor,
            );
        }
        lights.push((
            VulkanPointLight {
                position: frame.position,
                rgb: [frame.color[0], frame.color[1], frame.color[2]],
                range: frame.range,
                coefficients: frame.attenuation,
                active: true,
            },
            frame.native_flags,
        ));
    }
    lights
}

fn fx_command_vec3(command: &FxCommand, offset: usize) -> Option<[f32; 3]> {
    let mut result = [0.0; 3];
    for (axis, value) in result.iter_mut().enumerate() {
        let start = offset.checked_add(axis.checked_mul(4)?)?;
        let bytes = command.raw_body.get(start..start.checked_add(4)?)?;
        *value = f32::from_le_bytes(bytes.try_into().ok()?);
    }
    Some(result)
}

fn report_control_point_lights_once(
    reported: &mut bool,
    control_clock_ms: u32,
    target_clock_ms: Option<u32>,
    environment_count: usize,
    raw_control_lights: &[(VulkanPointLight, u32)],
    ordinary_control_lights: &[VulkanPointLight],
) {
    if *reported || std::env::var_os("FPARKAN_CONTROL_POINT_LIGHT_DIAGNOSTIC").is_none() {
        return;
    }
    if target_clock_ms.is_some_and(|target| control_clock_ms < target) {
        return;
    }
    eprintln!(
        "control_point_lights clock_ms={control_clock_ms} environment_count={environment_count} control_raw_count={} control_ordinary_count={} raw_flags={:?}",
        raw_control_lights.len(),
        ordinary_control_lights.len(),
        raw_control_lights.iter().map(|(_, flags)| *flags).collect::<Vec<_>>(),
    );
    *reported = true;
}

fn ordinary_control_point_lights(
    raw_control_lights: &[(VulkanPointLight, u32)],
) -> Vec<VulkanPointLight> {
    raw_control_lights
        .iter()
        .filter(|(light, flags)| light.active && flags & 0x8000_0000 == 0)
        .map(|(light, _)| *light)
        .collect()
}

fn initial_native_effect_phase(header_flags: u32, phase: f32) -> f32 {
    if header_flags & 0x80 != 0 {
        0.0
    } else {
        phase
    }
}

fn native_command_phase(header_flags: u32, phase: f32, random_phase_jitter: f32) -> f32 {
    let initial_phase = initial_native_effect_phase(header_flags, phase);
    if initial_phase == -1.0 {
        -1.0
    } else {
        (initial_phase
            + if header_flags & 1 != 0 {
                random_phase_jitter
            } else {
                0.0
            })
        .clamp(0.0, 1.0)
    }
}

fn control_row_points<'a>(
    point_list: &'a PreparedControlPointList,
    row: &PreparedControlEffectRow,
) -> Option<[&'a PreparedControlPoint; 3]> {
    let mut result = Vec::with_capacity(3);
    for offset in row.point_offsets {
        result.push(point_list.points.get(usize::try_from(offset).ok()?)?);
    }
    result.try_into().ok()
}

fn append_initial_control_effect_slots(
    root: &Path,
    mission_root: &MissionObjectDraft,
    object_index: usize,
    component_index: usize,
    control: &PreparedComponentControl,
    component_pose_buffer: Option<&NodePoseBuffer>,
    mount_pose: Option<VulkanNodePose>,
    mesh: &mut VulkanStaticMesh,
    materials: &mut Vec<VulkanStaticMaterial>,
    material_animations: &mut Vec<MaterialAnimationBinding>,
    effect_documents: &mut HashMap<String, FxDocument>,
    effect_materials: &mut HashMap<String, PreparedEffectMaterial>,
    slots: &mut Vec<AmbientEffectGpuSlot>,
    point_light_slots: &mut Vec<ControlPointLightSlot>,
) -> Result<(), String> {
    let Some(point_list) = control.point_list.as_ref() else {
        return Ok(());
    };
    for row in
        selected_initial_control_effect_rows(control.initial_effect_group, &control.effect_section)
    {
        let group_index = row.table_index;
        let archive = fixed_effect_field(&row.resource.archive);
        let name = fixed_effect_field(&row.resource.name);
        let points = control_row_points(point_list, row).ok_or_else(|| {
            format!(
                "Control group {group_index} row {} references a missing CPT point {:?}",
                row.row_index, row.point_offsets
            )
        })?;
        let key = format!("{archive}/{name}");
        if !effect_documents.contains_key(&key) {
            let bytes = load_resource_entry_bytes_from_root(root, &archive, &name)
                .map_err(|error| format!("load Control FX {key}: {error}"))?;
            let Ok(document) = decode_fxid(bytes) else {
                continue;
            };
            effect_documents.insert(key.clone(), document);
        }
        let document = effect_documents
            .get(&key)
            .ok_or_else(|| format!("Control FX {key} was not cached"))?;
        let header = document.header();
        let duration_seconds = header.duration_seconds;
        if !duration_seconds.is_finite()
            || duration_seconds < 0.0
            || !matches!(header.time_mode, 0 | 1 | 2)
            || (header.time_mode != 0 && duration_seconds <= 0.0)
            || !header.phase_jitter.is_finite()
            || !header.random_shift.iter().all(|value| value.is_finite())
            || !header.scale.iter().all(|value| value.is_finite())
        {
            // Control can reference action effects whose header timing and
            // scale conventions are outside this ambient subset. Leave them
            // unexpanded until their lifetime and transform contract are
            // understood rather than failing the whole mission preview.
            continue;
        }
        let owner_node_index =
            usize::try_from(points[0].raw_signed_field_04)
                .ok()
                .filter(|owner_node| {
                    component_pose_buffer
                        .is_some_and(|hierarchy| *owner_node < hierarchy.poses.len())
                        || (*owner_node == 0 && component_pose_buffer.is_none())
                });
        let Some(owner_node_index) = owner_node_index else {
            continue;
        };
        let owner_node_pose = control_effect_owner_node_pose(
            component_pose_buffer,
            mount_pose.is_some(),
            owner_node_index,
        );
        let Some(owner_node_pose) = owner_node_pose else {
            continue;
        };
        let root_transform = LegacyIron3dEulerTransform {
            translation: mission_root.position,
            orientation_radians: mission_root.orientation_raw,
        };
        let local_from_effect = control_type4_effect_local_matrix(points, header.scale)
            .ok_or_else(|| format!("Control FX {key} has an invalid type-4 transform"))?;
        let world_from_effect = control_type4_world_from_effect(
            local_from_effect,
            mission_root.scale,
            root_transform,
            mount_pose,
            owner_node_pose,
        )
        .ok_or_else(|| format!("Control FX {key} has an invalid owner transform"))?;
        let control_source = format!(
            "{}/{}",
            control.source.archive.as_str(),
            String::from_utf8_lossy(&control.source.name.0)
        );
        let random_instance_key = ControlEffectInstanceKey {
            object_index,
            component_index,
            table_index: row.table_index,
            row_index: row.row_index,
        };
        let random_seed = control_effect_instance_seed(
            object_index,
            component_index,
            row.table_index,
            row.row_index,
            &control_source,
        );

        for (command_index, command) in document.commands().iter().enumerate() {
            if ambient_effect_op1_supported(command) {
                point_light_slots.push(ControlPointLightSlot {
                    time_mode: header.time_mode,
                    header_flags: header.flags,
                    random_instance_key,
                    random_seed,
                    phase_jitter: header.phase_jitter,
                    random_shift: header.random_shift,
                    duration_seconds,
                    owner_object_index: object_index,
                    owner_component_index: component_index,
                    owner_node_index,
                    owner_component_is_mounted: mount_pose.is_some(),
                    root_transform,
                    owner_scale: mission_root.scale,
                    mount_pose,
                    local_from_effect,
                    world_from_effect,
                    command_index,
                    command: command.clone(),
                });
                continue;
            }
            let Some(kind) = ambient_effect_command_kind(command) else {
                continue;
            };
            if !ambient_effect_render_selector_allows_header(
                header.flags,
                CONTROL_COMPONENT_RENDER_SELECTOR,
            ) {
                continue;
            }
            let Some(reference) = command.resource_refs.first() else {
                continue;
            };
            let material_archive = String::from_utf8_lossy(reference.archive_name()).into_owned();
            let material_name = String::from_utf8_lossy(reference.resource_name()).into_owned();
            if material_archive.is_empty() || material_name.is_empty() {
                continue;
            }
            let cache_key = format!("{material_archive}/{material_name}");
            if !effect_materials.contains_key(&cache_key) {
                let _prepared = prepare_effect_material(
                    root,
                    &material_archive,
                    &material_name,
                    materials,
                    effect_materials,
                )?;
            }
            let prepared = effect_materials
                .get(&cache_key)
                .ok_or_else(|| format!("FX MAT0 {cache_key} was not cached"))?;
            if !ambient_effect_tint_supported(
                &prepared.phase_native_flag_40,
                &prepared.phase_directional_rgb,
                &prepared.phase_additive_rgb,
            ) {
                continue;
            }
            let first_material = *prepared
                .phase_material_indices
                .first()
                .ok_or_else(|| format!("FX MAT0 {cache_key} has no phase variants"))?;
            let op9_mesh_template =
                if kind == AmbientEffectKind::GenerBall && command.opcode == FxOpcode::Op9 {
                    let Some(template) = evaluate_f_gener_ball_mesh(
                        command,
                        command_index,
                        &world_from_effect,
                        0.0,
                        0.0,
                        [0.0; 3],
                        AMBIENT_EFFECT_NATIVE_CATEGORY,
                    ) else {
                        continue;
                    };
                    Some(template)
                } else {
                    None
                };
            let op9_primitive_layout = op9_mesh_template
                .as_ref()
                .map(ambient_effect_mesh_primitive_layout)
                .transpose()?;
            let placeholder: [VulkanStaticVertex; 4] = std::array::from_fn(|index| {
                environment_vertex_with_alpha(
                    [0.0; 3],
                    [1.0; 3],
                    0.0,
                    [[0.0, 0.99], [0.0, 0.0], [0.99, 0.0], [0.99, 0.99]][index],
                )
            });
            let pipeline_state = ambient_effect_pipeline_state(prepared.initial_pipeline_category)
                .ok_or_else(|| {
                    format!(
                        "FX MAT0 {cache_key} has unsupported pipeline category {}",
                        prepared.initial_pipeline_category
                    )
                })?;
            let pool_capacity = match kind {
                AmbientEffectKind::SmokePool => ambient_effect_pool_capacity(command)
                    .ok_or_else(|| format!("FX Op8 {cache_key} has an invalid pool size"))?,
                AmbientEffectKind::Op7ParticlePool => ambient_effect_op7_range_capacity(command)
                    .ok_or_else(|| format!("FX Op7 {cache_key} has an invalid particle pool"))?,
                _ => 1,
            };
            let range_capacity = op9_primitive_layout
                .as_ref()
                .map_or(pool_capacity, Vec::len);
            let mut particle_ranges = Vec::with_capacity(range_capacity);
            let mut particle_material_animation_indices = Vec::with_capacity(range_capacity);
            for _ in 0..pool_capacity {
                if let (Some(template), Some(primitives)) =
                    (&op9_mesh_template, &op9_primitive_layout)
                {
                    for primitive in primitives {
                        let vertices = ambient_effect_mesh_primitive_vertices(template, *primitive);
                        let indices = ambient_effect_mesh_primitive_indices(template, *primitive)?;
                        let range = append_environment_range(
                            mesh,
                            first_material,
                            vertices,
                            indices,
                            pipeline_state,
                        )?;
                        let material_animation_index = append_effect_material_animation(
                            prepared,
                            range.range_index,
                            material_animations,
                        );
                        particle_ranges.push(range);
                        particle_material_animation_indices.push(material_animation_index);
                    }
                } else {
                    let range = append_environment_range(
                        mesh,
                        first_material,
                        placeholder.to_vec(),
                        vec![0, 1, 2, 2, 3, 0],
                        pipeline_state,
                    )?;
                    let material_animation_index = append_effect_material_animation(
                        prepared,
                        range.range_index,
                        material_animations,
                    );
                    particle_ranges.push(range);
                    particle_material_animation_indices.push(material_animation_index);
                }
            }
            let range = particle_ranges.remove(0);
            let material_animation_index = particle_material_animation_indices.remove(0);
            let smoke_emitter_state = (kind == AmbientEffectKind::SmokePool).then(|| {
                let seed = ambient_effect_seed(
                    object_index,
                    component_index,
                    row.table_index,
                    row.row_index,
                    command_index,
                    &control_source,
                );
                SmokeEmitterState::new(seed, seed, seed)
            });
            let op7_emitter_state = (kind == AmbientEffectKind::Op7ParticlePool).then(|| {
                let seed = ambient_effect_seed(
                    object_index,
                    component_index,
                    row.table_index,
                    row.row_index,
                    command_index,
                    &control_source,
                );
                Op7EmitterState::new(seed, seed)
            });
            slots.push(AmbientEffectGpuSlot {
                kind,
                time_mode: header.time_mode,
                header_flags: header.flags,
                random_instance_key,
                random_seed,
                phase_jitter: header.phase_jitter,
                random_shift: header.random_shift,
                owner_object_index: object_index,
                owner_component_index: component_index,
                owner_node_index,
                owner_component_is_mounted: mount_pose.is_some(),
                root_transform,
                owner_scale: mission_root.scale,
                mount_pose,
                local_from_effect,
                control_source: control_source.clone(),
                control_table_index: row.table_index,
                control_row_index: row.row_index,
                control_point_indices: row.point_offsets,
                control_point_owners: points.map(|point| point.raw_signed_field_04),
                command: command.clone(),
                command_index,
                duration_seconds,
                world_from_effect,
                range,
                additional_particle_ranges: particle_ranges,
                material_animation_index,
                additional_particle_material_animation_indices: particle_material_animation_indices,
                smoke_emitter_state,
                op7_emitter_state,
            });
        }
    }
    Ok(())
}

fn selected_initial_control_effect_rows<'a>(
    group_index: Option<usize>,
    section: &'a PreparedControlEffectSection,
) -> Vec<&'a PreparedControlEffectRow> {
    let (Some(group_index), PreparedControlEffectSection::Parsed(rows)) = (group_index, section)
    else {
        return Vec::new();
    };
    rows.iter()
        .filter(|row| {
            row.table_index == group_index && ambient_effect_row_unconditionally_active(row)
        })
        .collect()
}

fn ambient_effect_row_unconditionally_active(row: &PreparedControlEffectRow) -> bool {
    // Control22C0 returns true when none of the predicate bits are set. The
    // two row-chain bits have separate dispatch semantics and stay excluded.
    row.raw_condition[0] & 0xF000_0000 == 0
}

fn ambient_effect_command_kind(command: &FxCommand) -> Option<AmbientEffectKind> {
    let body = command.raw_body.as_ref();
    let mode = body
        .get(..4)
        .map(|bytes| u32::from_le_bytes(bytes.try_into().expect("four byte FX body mode")));
    let body_c4 = body
        .get(0xc4..0xc8)
        .map(|bytes| u32::from_le_bytes(bytes.try_into().expect("four byte FX C4 field")));
    match (command.opcode, mode, body_c4) {
        (FxOpcode::Op3, Some(0), _) if command.raw_body.len() >= 0xC4 => {
            Some(AmbientEffectKind::Op3Type0)
        }
        (FxOpcode::Op3, Some(1), _) if command.raw_body.len() >= 0xC4 => {
            Some(AmbientEffectKind::Op3Type1)
        }
        (FxOpcode::Op3, Some(2), _) => Some(AmbientEffectKind::Op3Type2),
        (FxOpcode::Op9, Some(2), Some(0..=2)) => Some(AmbientEffectKind::GenerBall),
        (FxOpcode::Op7, _, _) if ambient_effect_op7_range_capacity(command).is_some() => {
            Some(AmbientEffectKind::Op7ParticlePool)
        }
        (FxOpcode::Op8, _, _) if ambient_effect_pool_capacity(command).is_some() => {
            Some(AmbientEffectKind::SmokePool)
        }
        (FxOpcode::Op4, Some(0), Some(denominator_bits))
            if f32::from_bits(denominator_bits).is_finite()
                && f32::from_bits(denominator_bits) > 0.0 =>
        {
            Some(AmbientEffectKind::GenerBall)
        }
        _ => None,
    }
}

const CONTROL_COMPONENT_RENDER_SELECTOR: u32 = 1;

fn ambient_effect_render_selector_allows_header(header_flags: u32, render_selector: u32) -> bool {
    // Effect.dll 0x7D10 suppresses header flag 0x800 only for selector zero.
    // The native AniMesh component path was observed calling the manager with
    // selector one while its 0xD00 f_smalllight_y entries were present.
    render_selector != 0 || header_flags & 0x800 == 0
}

fn ambient_effect_op1_supported(command: &FxCommand) -> bool {
    if command.opcode != FxOpcode::Op1 {
        return false;
    }
    let Some(effect_type) = command
        .raw_body
        .get(..4)
        .and_then(|bytes| bytes.try_into().ok())
        .map(u32::from_le_bytes)
    else {
        return false;
    };
    command.raw_body.len() >= 132 && matches!(effect_type, 1 | 2 | 5 | 6 | 7)
}

fn ambient_effect_pool_capacity(command: &FxCommand) -> Option<usize> {
    if command.opcode != FxOpcode::Op8 {
        return None;
    }
    let pool_count = usize::try_from(u32::from_le_bytes(
        command.raw_body.get(0x20..0x24)?.try_into().ok()?,
    ))
    .ok()?;
    (1..=4096).contains(&pool_count).then_some(pool_count)
}

fn ambient_effect_op7_range_capacity(command: &FxCommand) -> Option<usize> {
    if command.opcode != FxOpcode::Op7 || command.raw_body.len() < 0xCC {
        return None;
    }
    let read_u32 = |offset: usize| -> Option<u32> {
        Some(u32::from_le_bytes(
            command.raw_body.get(offset..offset + 4)?.try_into().ok()?,
        ))
    };
    let read_f32 = |offset| read_u32(offset).map(f32::from_bits);
    // The evaluator uses the traced default world scalar of 10 for this
    // Control path; the command's acceleration is supported when finite.
    let material_phase_factor = read_f32(0x1C)?;
    if !matches!(read_u32(0x00)?, 0 | 1)
        || !material_phase_factor.is_finite()
        || material_phase_factor == 0.0
        || !read_f32(0x88)?.is_finite()
    {
        return None;
    }
    let pool_count = usize::try_from(read_u32(0x20)?).ok()?;
    let copies_per_group = usize::try_from(read_u32(0x24)?).ok()?;
    let capacity = pool_count.checked_mul(copies_per_group)?;
    (1..=4096).contains(&capacity).then_some(capacity)
}

fn ambient_effect_seed(
    object_index: usize,
    component_index: usize,
    table_index: usize,
    row_index: usize,
    command_index: usize,
    source: &str,
) -> u32 {
    let mut hash = 0x811C_9DC5_u32;
    for byte in source.bytes().chain(
        [
            object_index,
            component_index,
            table_index,
            row_index,
            command_index,
        ]
        .into_iter()
        .flat_map(|value| (value as u64).to_le_bytes()),
    ) {
        hash = (hash ^ u32::from(byte)).wrapping_mul(0x0100_0193);
    }
    if hash == 0 {
        1
    } else {
        hash
    }
}

fn control_effect_instance_seed(
    object_index: usize,
    component_index: usize,
    table_index: usize,
    row_index: usize,
    source: &str,
) -> u32 {
    ambient_effect_seed(
        object_index,
        component_index,
        table_index,
        row_index,
        0,
        source,
    )
}

fn advance_control_effect_random_states(
    states: &mut HashMap<ControlEffectInstanceKey, ControlEffectRandomState>,
    ambient_slots: &[AmbientEffectGpuSlot],
    point_light_slots: &[ControlPointLightSlot],
    sample_id: SceneSampleId,
    control_clock_ms: u32,
    elapsed_seconds: f32,
) -> HashMap<ControlEffectInstanceKey, ControlEffectRandomSample> {
    let mut specifications = HashMap::new();
    for slot in ambient_slots {
        let initial_phase = ambient_effect_phase(
            slot.time_mode,
            slot.header_flags,
            elapsed_seconds,
            slot.duration_seconds,
        )
        .map(|phase| initial_native_effect_phase(slot.header_flags, phase))
        .unwrap_or(-1.0);
        specifications.entry(slot.random_instance_key).or_insert((
            slot.random_seed,
            slot.header_flags,
            slot.phase_jitter,
            slot.random_shift,
            initial_phase,
        ));
    }
    for slot in point_light_slots {
        let initial_phase = ambient_effect_phase(
            slot.time_mode,
            slot.header_flags,
            elapsed_seconds,
            slot.duration_seconds,
        )
        .map(|phase| initial_native_effect_phase(slot.header_flags, phase))
        .unwrap_or(-1.0);
        specifications.entry(slot.random_instance_key).or_insert((
            slot.random_seed,
            slot.header_flags,
            slot.phase_jitter,
            slot.random_shift,
            initial_phase,
        ));
    }

    specifications
        .into_iter()
        .map(
            |(key, (seed, flags, phase_jitter, random_shift, initial_phase))| {
                let state = states.entry(key).or_insert_with(|| {
                    ControlEffectRandomState::new(seed, flags, phase_jitter, random_shift)
                });
                (
                    key,
                    state.advance(sample_id, control_clock_ms, initial_phase),
                )
            },
        )
        .collect()
}

fn ambient_effect_ranges(slot: &AmbientEffectGpuSlot) -> Vec<(&EnvironmentGpuRange, usize)> {
    std::iter::once((&slot.range, slot.material_animation_index))
        .chain(
            slot.additional_particle_ranges
                .iter()
                .zip(&slot.additional_particle_material_animation_indices)
                .map(|(range, &binding)| (range, binding)),
        )
        .collect()
}

fn ambient_effect_quad_center(vertices: &[[f32; 3]; 4]) -> [f32; 3] {
    std::array::from_fn(|axis| vertices.iter().map(|vertex| vertex[axis]).sum::<f32>() / 4.0)
}

fn ambient_effect_quad_size(vertices: &[[f32; 3]; 4]) -> [f32; 2] {
    let edge_length = |a: [f32; 3], b: [f32; 3]| {
        ((a[0] - b[0]).powi(2) + (a[1] - b[1]).powi(2) + (a[2] - b[2]).powi(2)).sqrt()
    };
    [
        edge_length(vertices[0], vertices[1]),
        edge_length(vertices[1], vertices[2]),
    ]
}

fn ambient_effect_projected_bounds(
    vertices: &[[f32; 3]; 4],
    clip_from_world: [f32; 16],
    viewport: [u32; 2],
) -> Option<[f32; 4]> {
    let mut points = [[0.0; 2]; 4];
    for (index, vertex) in vertices.iter().enumerate() {
        let clip = [
            vertex[0] * clip_from_world[0]
                + vertex[1] * clip_from_world[4]
                + vertex[2] * clip_from_world[8]
                + clip_from_world[12],
            vertex[0] * clip_from_world[1]
                + vertex[1] * clip_from_world[5]
                + vertex[2] * clip_from_world[9]
                + clip_from_world[13],
            vertex[0] * clip_from_world[2]
                + vertex[1] * clip_from_world[6]
                + vertex[2] * clip_from_world[10]
                + clip_from_world[14],
            vertex[0] * clip_from_world[3]
                + vertex[1] * clip_from_world[7]
                + vertex[2] * clip_from_world[11]
                + clip_from_world[15],
        ];
        if !clip.iter().all(|value| value.is_finite()) || clip[3] <= f32::EPSILON {
            return None;
        }
        points[index] = [
            (clip[0] / clip[3] + 1.0) * 0.5 * viewport[0] as f32,
            (clip[1] / clip[3] + 1.0) * 0.5 * viewport[1] as f32,
        ];
    }
    Some([
        points
            .iter()
            .map(|point| point[0])
            .fold(f32::INFINITY, f32::min),
        points
            .iter()
            .map(|point| point[1])
            .fold(f32::INFINITY, f32::min),
        points
            .iter()
            .map(|point| point[0])
            .fold(f32::NEG_INFINITY, f32::max),
        points
            .iter()
            .map(|point| point[1])
            .fold(f32::NEG_INFINITY, f32::max),
    ])
}

fn ambient_effect_range_for(
    slot: &AmbientEffectGpuSlot,
    range_index: usize,
) -> Option<&EnvironmentGpuRange> {
    std::iter::once(&slot.range)
        .chain(slot.additional_particle_ranges.iter())
        .find(|range| range.range_index == range_index)
}

fn ambient_effect_pipeline_state(category: u8) -> Option<LegacyPipelineState> {
    world_pipeline_state(LegacyBlendMode::SourceAlpha, LegacyDepthMode::TestReadOnly)
        .with_material_category(category)
}

fn ambient_effect_tint_supported(
    phase_native_flag_40: &[bool],
    phase_directional_rgb: &[[f32; 3]],
    phase_additive_rgb: &[[f32; 3]],
) -> bool {
    !phase_native_flag_40.is_empty()
        && phase_native_flag_40.len() == phase_directional_rgb.len()
        && phase_native_flag_40.len() == phase_additive_rgb.len()
        && phase_native_flag_40.iter().all(|flag| !flag)
        && phase_directional_rgb
            .iter()
            .zip(phase_additive_rgb)
            .all(|(directional, additive)| {
                directional
                    .iter()
                    .chain(additive)
                    .all(|channel| channel.is_finite() && (0.0..=1.0).contains(channel))
                    && (0..3).all(|channel| additive[channel] > 0.0 || directional[channel] == 0.0)
            })
}

fn fixed_effect_field(field: &[u8; 32]) -> String {
    let length = field
        .iter()
        .position(|byte| *byte == 0)
        .unwrap_or(field.len());
    String::from_utf8_lossy(&field[..length]).trim().to_owned()
}

fn update_ambient_effect_geometry(
    slots: &mut [AmbientEffectGpuSlot],
    component_pose_buffers: &[Vec<Option<NodePoseBuffer>>],
    mesh: &mut VulkanStaticMesh,
    material_animations: &mut [MaterialAnimationBinding],
    elapsed_seconds: f32,
    random_samples: &HashMap<ControlEffectInstanceKey, ControlEffectRandomSample>,
    camera_world: [f32; 3],
) -> Result<Vec<AmbientEffectGeometryUpdate>, String> {
    let mut updates = Vec::with_capacity(slots.len());
    for slot in slots {
        let random_sample = random_samples
            .get(&slot.random_instance_key)
            .copied()
            .unwrap_or_default();
        let Some(world_from_effect) = ambient_effect_world_from_component_pose_with_random_shift(
            slot,
            component_pose_buffers,
            random_sample.accumulated_shift,
        ) else {
            deactivate_ambient_effect_slot(slot, material_animations, &mut updates)?;
            continue;
        };
        slot.world_from_effect = world_from_effect;
        let Some(phase) = ambient_effect_phase(
            slot.time_mode,
            slot.header_flags,
            elapsed_seconds,
            slot.duration_seconds,
        )
        .map(|phase| native_command_phase(slot.header_flags, phase, random_sample.phase_jitter)) else {
            deactivate_ambient_effect_slot(slot, material_animations, &mut updates)?;
            continue;
        };
        if slot.kind == AmbientEffectKind::GenerBall && slot.command.opcode == FxOpcode::Op9 {
            let Some(frame) = evaluate_f_gener_ball_mesh(
                &slot.command,
                slot.command_index,
                &slot.world_from_effect,
                phase,
                elapsed_seconds,
                camera_world,
                AMBIENT_EFFECT_NATIVE_CATEGORY,
            ) else {
                deactivate_ambient_effect_slot(slot, material_animations, &mut updates)?;
                continue;
            };
            let primitives = ambient_effect_mesh_primitive_layout(&frame)?;
            let ranges = ambient_effect_ranges(slot);
            if ranges.len() != primitives.len() {
                return Err(format!(
                    "ambient Op9 draw range count changed ({} != {})",
                    ranges.len(),
                    primitives.len()
                ));
            }
            for (primitive, (range, material_animation_index)) in primitives.into_iter().zip(ranges)
            {
                let binding = material_animations
                    .get_mut(material_animation_index)
                    .ok_or_else(|| "ambient FX material binding is out of bounds".to_string())?;
                binding.normalized_phase_override = Some(frame.material_phase);
                write_ambient_effect_mesh_primitive(mesh, range, &frame, primitive)?;
                updates.push(AmbientEffectGeometryUpdate {
                    range_index: range.range_index,
                    index_count: if frame.active && frame.color[3] > 0.0 {
                        u32::try_from(primitive.index_count)
                            .map_err(|_| "ambient Op9 index count exceeds u32".to_string())?
                    } else {
                        0
                    },
                    command_rgb: [frame.color[0], frame.color[1], frame.color[2]],
                });
            }
            continue;
        }
        let frames = match (slot.kind, slot.command.opcode) {
            (AmbientEffectKind::Op3Type0, FxOpcode::Op3) => evaluate_op3_type0_command(
                &slot.command,
                slot.command_index,
                &slot.world_from_effect,
                elapsed_seconds,
                phase,
                camera_world,
            )
            .into_iter()
            .collect(),
            (AmbientEffectKind::Op7ParticlePool, FxOpcode::Op7) => {
                let Some(state) = slot.op7_emitter_state.as_mut() else {
                    deactivate_ambient_effect_slot(slot, material_animations, &mut updates)?;
                    continue;
                };
                let Some(frames) = evaluate_op7_emitter(
                    &slot.command,
                    slot.command_index,
                    &slot.world_from_effect,
                    camera_world,
                    phase,
                    elapsed_seconds,
                    Op7RenderContext {
                        detail_level: 0,
                        // At detail level zero, [0,1) cutoffs with zero bias
                        // are all visible. The native quality preset remains
                        // unresolved, but no particle is culled here.
                        visibility: Op7VisibilityProfile {
                            width: 1.0,
                            bias: 0.0,
                        },
                        // Terrain.dll initializes the native world's world
                        // scalar to 10.0. An engine integration can supply the
                        // live value after it exposes the world setting.
                        world_scalar: 10.0,
                    },
                    state,
                ) else {
                    deactivate_ambient_effect_slot(slot, material_animations, &mut updates)?;
                    continue;
                };
                fx_material_speed_diagnostic(slot, 0xAC, elapsed_seconds, phase, &frames);
                frames
            }
            (AmbientEffectKind::SmokePool, FxOpcode::Op8) => {
                let Some(state) = slot.smoke_emitter_state.as_mut() else {
                    deactivate_ambient_effect_slot(slot, material_animations, &mut updates)?;
                    continue;
                };
                let frames = evaluate_op8_emitter(
                    &slot.command,
                    slot.command_index,
                    &slot.world_from_effect,
                    camera_world,
                    elapsed_seconds,
                    phase,
                    0,
                    Op8DetailThresholdRange::new(1.0, 1.0)
                        .expect("ordered finite Op8 material threshold"),
                    state,
                )
                .unwrap_or_default();
                smoke_fr_02_diagnostic(slot, elapsed_seconds, phase, &frames);
                fx_material_speed_diagnostic(slot, 0xD4, elapsed_seconds, phase, &frames);
                frames
            }
            (AmbientEffectKind::Op3Type1, FxOpcode::Op3) => evaluate_op3_type1_command(
                &slot.command,
                slot.command_index,
                &slot.world_from_effect,
                elapsed_seconds,
                phase,
                camera_world,
            )
            .into_iter()
            .collect(),
            (AmbientEffectKind::Op3Type2, FxOpcode::Op3) => evaluate_op3_type2_command(
                &slot.command,
                slot.command_index,
                &slot.world_from_effect,
                elapsed_seconds,
                phase,
                0,
            )
            .into_iter()
            .collect(),
            (AmbientEffectKind::GenerBall, FxOpcode::Op4) => evaluate_f_gener_ball(
                &slot.command,
                slot.command_index,
                &slot.world_from_effect,
                phase,
                elapsed_seconds,
                camera_world,
            )
            .into_iter()
            .collect(),
            _ => Vec::new(),
        };
        let ranges = ambient_effect_ranges(slot);
        if frames.is_empty() {
            deactivate_ambient_effect_slot(slot, material_animations, &mut updates)?;
            continue;
        }
        let variable_pool = slot.kind == AmbientEffectKind::Op7ParticlePool;
        let aligned_frames = align_ambient_effect_frames(frames, ranges.len(), variable_pool)?;
        for ((range, material_animation_index), frame) in ranges.into_iter().zip(aligned_frames) {
            if let Some(frame) = frame {
                let binding = material_animations
                    .get_mut(material_animation_index)
                    .ok_or_else(|| "ambient FX material binding is out of bounds".to_string())?;
                binding.normalized_phase_override = Some(frame.material_phase);
                write_ambient_effect_frame(mesh, range, &frame)?;
                updates.push(AmbientEffectGeometryUpdate {
                    range_index: range.range_index,
                    index_count: if frame.active && frame.color[3] > 0.0 {
                        6
                    } else {
                        0
                    },
                    command_rgb: [frame.color[0], frame.color[1], frame.color[2]],
                });
            } else {
                deactivate_ambient_effect_range(
                    range,
                    material_animation_index,
                    material_animations,
                    &mut updates,
                )?;
            }
        }
    }
    Ok(updates)
}

fn align_ambient_effect_frames(
    frames: Vec<fparkan_fx::fx_visual::EffectQuadFrame>,
    range_count: usize,
    variable_pool: bool,
) -> Result<Vec<Option<fparkan_fx::fx_visual::EffectQuadFrame>>, String> {
    if (variable_pool && frames.len() > range_count)
        || (!variable_pool && frames.len() != range_count)
    {
        return Err(format!(
            "ambient FX frame pool has {} particles but {range_count} draw ranges",
            frames.len()
        ));
    }
    let active_count = frames.len();
    let mut aligned: Vec<_> = frames.into_iter().map(Some).collect();
    aligned.extend(std::iter::repeat_with(|| None).take(range_count - active_count));
    Ok(aligned)
}

fn deactivate_ambient_effect_slot(
    slot: &AmbientEffectGpuSlot,
    material_animations: &mut [MaterialAnimationBinding],
    updates: &mut Vec<AmbientEffectGeometryUpdate>,
) -> Result<(), String> {
    for (range, material_animation_index) in ambient_effect_ranges(slot) {
        deactivate_ambient_effect_range(
            range,
            material_animation_index,
            material_animations,
            updates,
        )?;
    }
    Ok(())
}

fn deactivate_ambient_effect_range(
    range: &EnvironmentGpuRange,
    material_animation_index: usize,
    material_animations: &mut [MaterialAnimationBinding],
    updates: &mut Vec<AmbientEffectGeometryUpdate>,
) -> Result<(), String> {
    let binding = material_animations
        .get_mut(material_animation_index)
        .ok_or_else(|| "ambient FX material binding is out of bounds".to_string())?;
    binding.normalized_phase_override = Some(0.0);
    updates.push(AmbientEffectGeometryUpdate {
        range_index: range.range_index,
        index_count: 0,
        command_rgb: [0.0; 3],
    });
    Ok(())
}

fn write_ambient_effect_frame(
    mesh: &mut VulkanStaticMesh,
    range: &EnvironmentGpuRange,
    frame: &fparkan_fx::fx_visual::EffectQuadFrame,
) -> Result<(), String> {
    let end = range
        .vertex_start
        .checked_add(range.vertex_capacity)
        .ok_or_else(|| "ambient FX vertex range overflows".to_string())?;
    let destination = mesh
        .vertices
        .get_mut(range.vertex_start..end)
        .ok_or_else(|| "ambient FX vertex allocation is out of bounds".to_string())?;
    if destination.len() != 4 {
        return Err("ambient FX quad allocation changed after GPU preparation".to_string());
    }
    for (index, target) in destination.iter_mut().enumerate() {
        *target = environment_vertex_with_alpha(
            frame.vertices[index],
            [frame.color[0], frame.color[1], frame.color[2]],
            frame.color[3].clamp(0.0, 1.0),
            frame.uv[index],
        );
    }
    Ok(())
}

fn ambient_effect_mesh_primitive_layout(
    frame: &fparkan_fx::fx_visual::EffectMeshFrame,
) -> Result<Vec<AmbientEffectMeshPrimitive>, String> {
    if frame.vertices.len() != frame.uv.len() || frame.indices.is_empty() {
        return Err("ambient Op9 mesh has mismatched vertices/UVs or no indices".to_string());
    }
    let quad_count = frame
        .indices
        .len()
        .checked_sub(frame.vertices.len())
        .filter(|difference| difference.is_multiple_of(2))
        .map(|difference| difference / 2)
        .ok_or_else(|| "ambient Op9 mesh is not a native quad/cap layout".to_string())?;
    let quad_vertex_count = quad_count
        .checked_mul(4)
        .ok_or_else(|| "ambient Op9 quad vertex count overflows".to_string())?;
    let quad_index_count = quad_count
        .checked_mul(6)
        .ok_or_else(|| "ambient Op9 quad index count overflows".to_string())?;
    let cap_vertex_count = frame
        .vertices
        .len()
        .checked_sub(quad_vertex_count)
        .filter(|count| count.is_multiple_of(3))
        .ok_or_else(|| "ambient Op9 mesh has an invalid cap vertex count".to_string())?;
    let cap_count = cap_vertex_count / 3;
    let cap_index_count = cap_count
        .checked_mul(3)
        .ok_or_else(|| "ambient Op9 cap index count overflows".to_string())?;
    if quad_index_count + cap_index_count != frame.indices.len() {
        return Err("ambient Op9 quad and cap index counts do not match the frame".to_string());
    }

    // The native generator appends all quads first, then its triangle cap fan.
    let mut primitives = Vec::with_capacity(quad_count + cap_count);
    for quad in 0..quad_count {
        let vertex_start = quad * 4;
        let index_start = quad * 6;
        let base = u16::try_from(vertex_start)
            .map_err(|_| "ambient Op9 quad vertex exceeds u16".to_string())?;
        let expected = [base, base + 1, base + 2, base + 2, base + 3, base];
        if frame.indices.get(index_start..index_start + expected.len()) != Some(&expected) {
            return Err("ambient Op9 quad topology changed from native ordering".to_string());
        }
        primitives.push(AmbientEffectMeshPrimitive {
            vertex_start,
            vertex_count: 4,
            index_start,
            index_count: 6,
        });
    }
    for cap in 0..cap_count {
        let vertex_start = quad_vertex_count + cap * 3;
        let index_start = quad_index_count + cap * 3;
        let base = u16::try_from(vertex_start)
            .map_err(|_| "ambient Op9 cap vertex exceeds u16".to_string())?;
        let expected = [base, base + 1, base + 2];
        if frame.indices.get(index_start..index_start + expected.len()) != Some(&expected) {
            return Err("ambient Op9 cap topology changed from native ordering".to_string());
        }
        primitives.push(AmbientEffectMeshPrimitive {
            vertex_start,
            vertex_count: 3,
            index_start,
            index_count: 3,
        });
    }
    if primitives.is_empty() {
        return Err("ambient Op9 mesh contains no native draw primitives".to_string());
    }
    Ok(primitives)
}

fn ambient_effect_mesh_primitive_vertices(
    frame: &fparkan_fx::fx_visual::EffectMeshFrame,
    primitive: AmbientEffectMeshPrimitive,
) -> Vec<VulkanStaticVertex> {
    let end = primitive.vertex_start + primitive.vertex_count;
    frame.vertices[primitive.vertex_start..end]
        .iter()
        .zip(&frame.uv[primitive.vertex_start..end])
        .map(|(position, uv)| {
            environment_vertex_with_alpha(
                *position,
                [frame.color[0], frame.color[1], frame.color[2]],
                frame.color[3].clamp(0.0, 1.0),
                *uv,
            )
        })
        .collect()
}

fn ambient_effect_mesh_primitive_indices(
    frame: &fparkan_fx::fx_visual::EffectMeshFrame,
    primitive: AmbientEffectMeshPrimitive,
) -> Result<Vec<u32>, String> {
    let index_end = primitive.index_start + primitive.index_count;
    frame.indices[primitive.index_start..index_end]
        .iter()
        .map(|index| {
            usize::from(*index)
                .checked_sub(primitive.vertex_start)
                .and_then(|local| u32::try_from(local).ok())
                .ok_or_else(|| {
                    "ambient Op9 primitive index is outside its vertex block".to_string()
                })
        })
        .collect()
}

fn write_ambient_effect_mesh_primitive(
    mesh: &mut VulkanStaticMesh,
    range: &EnvironmentGpuRange,
    frame: &fparkan_fx::fx_visual::EffectMeshFrame,
    primitive: AmbientEffectMeshPrimitive,
) -> Result<(), String> {
    if range.vertex_capacity != primitive.vertex_count {
        return Err("ambient Op9 primitive vertex allocation changed".to_string());
    }
    let vertex_end = range
        .vertex_start
        .checked_add(range.vertex_capacity)
        .ok_or_else(|| "ambient Op9 vertex range overflows".to_string())?;
    let destination = mesh
        .vertices
        .get_mut(range.vertex_start..vertex_end)
        .ok_or_else(|| "ambient Op9 vertex allocation is out of bounds".to_string())?;
    let draw_range = mesh
        .draw_ranges
        .get(range.range_index)
        .ok_or_else(|| "ambient Op9 draw range is out of bounds".to_string())?;
    let index_start = usize::try_from(draw_range.first_index)
        .map_err(|_| "ambient Op9 first index exceeds usize".to_string())?;
    let index_end = index_start
        .checked_add(primitive.index_count)
        .ok_or_else(|| "ambient Op9 index range overflows".to_string())?;
    let current_indices = mesh
        .indices
        .get(index_start..index_end)
        .ok_or_else(|| "ambient Op9 index allocation is out of bounds".to_string())?;
    let frame_indices = frame
        .indices
        .get(primitive.index_start..primitive.index_start + primitive.index_count)
        .ok_or_else(|| "ambient Op9 source primitive index range is out of bounds".to_string())?;
    for (current, local) in current_indices.iter().zip(frame_indices) {
        let primitive_local = usize::from(*local)
            .checked_sub(primitive.vertex_start)
            .ok_or_else(|| "ambient Op9 source index leaves its primitive".to_string())?;
        let expected = u32::try_from(range.vertex_start)
            .ok()
            .and_then(|base| base.checked_add(u32::try_from(primitive_local).ok()?))
            .ok_or_else(|| "ambient Op9 primitive index exceeds u32".to_string())?;
        if *current != expected {
            return Err("ambient Op9 primitive topology changed after GPU preparation".to_string());
        }
    }
    let frame_vertex_end = primitive
        .vertex_start
        .checked_add(primitive.vertex_count)
        .ok_or_else(|| "ambient Op9 source primitive vertex range overflows".to_string())?;
    let frame_vertices = frame
        .vertices
        .get(primitive.vertex_start..frame_vertex_end)
        .ok_or_else(|| "ambient Op9 source primitive vertex range is out of bounds".to_string())?;
    let frame_uvs = frame
        .uv
        .get(primitive.vertex_start..frame_vertex_end)
        .ok_or_else(|| "ambient Op9 source primitive UV range is out of bounds".to_string())?;
    for ((target, position), uv) in destination.iter_mut().zip(frame_vertices).zip(frame_uvs) {
        *target = environment_vertex_with_alpha(
            *position,
            [frame.color[0], frame.color[1], frame.color[2]],
            frame.color[3].clamp(0.0, 1.0),
            *uv,
        );
    }
    Ok(())
}

fn ambient_effect_vertex_rgb(command_rgb: [f32; 3], material_additive_rgb: [f32; 3]) -> [f32; 3] {
    std::array::from_fn(|channel| command_rgb[channel] * material_additive_rgb[channel])
}

fn apply_ambient_effect_material_tints(
    slots: &[AmbientEffectGpuSlot],
    mesh: &mut VulkanStaticMesh,
    updates: &[AmbientEffectGeometryUpdate],
    active_materials: &HashMap<usize, ActiveMaterialState>,
) -> Result<(), String> {
    for update in updates.iter().filter(|update| update.index_count > 0) {
        let range = slots
            .iter()
            .find_map(|slot| ambient_effect_range_for(slot, update.range_index))
            .ok_or_else(|| "ambient FX draw range has no owning slot".to_string())?;
        let material = active_materials
            .get(&update.range_index)
            .ok_or_else(|| "ambient FX draw range has no active MAT0 phase".to_string())?;
        let vertex_rgb = ambient_effect_vertex_rgb(update.command_rgb, material.additive_rgb);
        let end = range
            .vertex_start
            .checked_add(range.vertex_capacity)
            .ok_or_else(|| "ambient FX vertex range overflows".to_string())?;
        let vertices = mesh
            .vertices
            .get_mut(range.vertex_start..end)
            .ok_or_else(|| "ambient FX vertex allocation is out of bounds".to_string())?;
        for vertex in vertices {
            vertex.color = vertex_rgb;
        }
    }
    Ok(())
}

fn ambient_effect_draw_sort_keys(
    mesh: &VulkanStaticMesh,
    slots: &[AmbientEffectGpuSlot],
    camera_world: [f32; 3],
) -> Result<Vec<(usize, f32)>, String> {
    slots.iter().try_fold(Vec::new(), |mut keys, slot| {
        for (range, _) in ambient_effect_ranges(slot) {
            keys.push((
                range.range_index,
                first_indexed_vertex_distance(mesh, range.range_index, camera_world)?,
            ));
        }
        Ok(keys)
    })
}

fn world_draw_range_indices(
    draw_range_count: usize,
    fixed_range_indices: &HashSet<usize>,
) -> Vec<usize> {
    (0..draw_range_count)
        .filter(|range_index| !fixed_range_indices.contains(range_index))
        .collect()
}

// TEMPORARY diagnostic for ROADMAP.md A.4 (smoke_fr_02 speed). Enabled by
// FPARKAN_DIAG_SMOKE; identifies the emitter by its Op8 body (pool 30,
// interval 0.08) and reports spawn rate, particle lifetime and rise speed
// once per two seconds of effect clock. Remove after the investigation.
#[derive(Default)]
struct SmokeDiagnosticTrack {
    window_start: Option<f32>,
    last_born: f32,
    spawns: usize,
    calls: usize,
    max_age: f32,
    sum_age: f64,
    sum_z: f64,
    sum_age_z: f64,
    sum_age_age: f64,
    samples: usize,
}

fn smoke_fr_02_diagnostic(
    slot: &AmbientEffectGpuSlot,
    clock: f32,
    phase: f32,
    frames: &[fparkan_fx::fx_visual::EffectQuadFrame],
) {
    static ENABLED: std::sync::OnceLock<bool> = std::sync::OnceLock::new();
    static TRACKS: std::sync::OnceLock<
        std::sync::Mutex<HashMap<(usize, usize, usize, usize, usize), SmokeDiagnosticTrack>>,
    > = std::sync::OnceLock::new();
    if !*ENABLED.get_or_init(|| std::env::var_os("FPARKAN_DIAG_SMOKE").is_some()) {
        return;
    }
    let body = slot.command.raw_body.as_ref();
    let read_u32 = |offset: usize| {
        body.get(offset..offset + 4)
            .map(|bytes| u32::from_le_bytes(bytes.try_into().expect("four bytes")))
    };
    if read_u32(0x20) != Some(30) || read_u32(0x14).map(f32::from_bits) != Some(0.08) {
        return;
    }
    let key = (
        slot.owner_object_index,
        slot.owner_component_index,
        slot.control_table_index,
        slot.control_row_index,
        slot.command_index,
    );
    let mut tracks = TRACKS
        .get_or_init(|| std::sync::Mutex::new(HashMap::new()))
        .lock()
        .expect("smoke diagnostic lock");
    let slot_count = tracks.len() + usize::from(!tracks.contains_key(&key));
    let track = tracks.entry(key).or_default();
    let window_start = *track.window_start.get_or_insert(clock);
    track.calls += 1;
    for frame in frames.iter().filter(|frame| frame.active) {
        let born = clock - frame.elapsed_seconds;
        if born > track.last_born + 1e-4 {
            track.spawns += 1;
            track.last_born = track.last_born.max(born);
        }
        let z = frame.vertices.iter().map(|vertex| vertex[2]).sum::<f32>() * 0.25;
        let age = f64::from(frame.elapsed_seconds);
        track.max_age = track.max_age.max(frame.elapsed_seconds);
        track.sum_age += age;
        track.sum_z += f64::from(z);
        track.sum_age_z += age * f64::from(z);
        track.sum_age_age += age * age;
        track.samples += 1;
    }
    let window = clock - window_start;
    if window < 2.0 {
        return;
    }
    let n = track.samples as f64;
    let rise_per_second = if n > 1.0 {
        (n * track.sum_age_z - track.sum_age * track.sum_z)
            / (n * track.sum_age_age - track.sum_age * track.sum_age)
    } else {
        0.0
    };
    let axis_lengths: [f32; 3] = std::array::from_fn(|column| {
        (0..3)
            .map(|row| slot.world_from_effect[row][column].powi(2))
            .sum::<f32>()
            .sqrt()
    });
    eprintln!(
        "smoke_diag slots={slot_count} key={key:?} clock={clock:.3} window={window:.3}s calls={} calls_per_s={:.1} spawns={} spawns_per_s={:.2} active_now={} max_age={:.3}s rise_per_s={rise_per_second:.2} rise_per_life_2_4s={:.1} phase={phase:.3} emitter=[{:.2},{:.2},{:.2}] effect_axes={axis_lengths:.3?}",
        track.calls,
        track.calls as f32 / window,
        track.spawns,
        track.spawns as f32 / window,
        frames.iter().filter(|frame| frame.active).count(),
        track.max_age,
        rise_per_second * 2.4,
        slot.world_from_effect[0][3],
        slot.world_from_effect[1][3],
        slot.world_from_effect[2][3],
    );
    *track = SmokeDiagnosticTrack {
        window_start: Some(clock),
        last_born: track.last_born,
        ..SmokeDiagnosticTrack::default()
    };
}

// TEMPORARY diagnostic for ROADMAP.md A.4 (animal "aura" speed). Enabled by
// FPARKAN_DIAG_FX_MATERIAL=<material name>, for example smoke_yg. Reports the
// effect-phase rate, call rate, particle lifetime and rise per particle life
// for every Op7/Op8 slot whose command uses that MAT0. Remove after the
// investigation.
#[derive(Default)]
struct FxSpeedDiagnosticTrack {
    window_start: Option<f32>,
    calls: usize,
    phase_travel: f32,
    last_phase: Option<f32>,
    max_age: f32,
    sum_t: f64,
    sum_z: f64,
    sum_tz: f64,
    sum_tt: f64,
    samples: usize,
}

fn fx_material_speed_diagnostic(
    slot: &AmbientEffectGpuSlot,
    material_name_offset: usize,
    clock: f32,
    phase: f32,
    frames: &[fparkan_fx::fx_visual::EffectQuadFrame],
) {
    static WANTED: std::sync::OnceLock<Option<String>> = std::sync::OnceLock::new();
    static TRACKS: std::sync::OnceLock<
        std::sync::Mutex<HashMap<(usize, usize, usize, usize, usize), FxSpeedDiagnosticTrack>>,
    > = std::sync::OnceLock::new();
    let Some(wanted) = WANTED
        .get_or_init(|| {
            std::env::var("FPARKAN_DIAG_FX_MATERIAL")
                .ok()
                .map(|name| name.to_ascii_lowercase())
        })
        .as_deref()
    else {
        return;
    };
    let body = slot.command.raw_body.as_ref();
    let Some(name) = body.get(material_name_offset..material_name_offset + 32) else {
        return;
    };
    let name = name.split(|byte| *byte == 0).next().unwrap_or_default();
    if !name.eq_ignore_ascii_case(wanted.as_bytes()) {
        return;
    }
    let key = (
        slot.owner_object_index,
        slot.owner_component_index,
        slot.control_table_index,
        slot.control_row_index,
        slot.command_index,
    );
    let mut tracks = TRACKS
        .get_or_init(|| std::sync::Mutex::new(HashMap::new()))
        .lock()
        .expect("fx diagnostic lock");
    let slot_count = tracks.len() + usize::from(!tracks.contains_key(&key));
    let track = tracks.entry(key).or_default();
    let window_start = *track.window_start.get_or_insert(clock);
    track.calls += 1;
    if let Some(last_phase) = track.last_phase {
        let delta = phase - last_phase;
        track.phase_travel += if delta < -0.5 { delta + 1.0 } else { delta };
    }
    track.last_phase = Some(phase);
    for frame in frames.iter().filter(|frame| frame.active) {
        // Op8 reports the particle age in seconds; Op7 reports its normalized
        // particle age, so the regression is per second or per life.
        let t = if slot.command.opcode == FxOpcode::Op8 {
            frame.elapsed_seconds
        } else {
            frame.normalized_time
        };
        let z = frame.vertices.iter().map(|vertex| vertex[2]).sum::<f32>() * 0.25;
        track.max_age = track.max_age.max(t);
        track.sum_t += f64::from(t);
        track.sum_z += f64::from(z);
        track.sum_tz += f64::from(t) * f64::from(z);
        track.sum_tt += f64::from(t) * f64::from(t);
        track.samples += 1;
    }
    let window = clock - window_start;
    if window < 3.0 {
        return;
    }
    let n = track.samples as f64;
    let slope = if n > 1.0 {
        (n * track.sum_tz - track.sum_t * track.sum_z)
            / (n * track.sum_tt - track.sum_t * track.sum_t)
    } else {
        0.0
    };
    eprintln!(
        "fx_diag material={wanted} op={:?} slots={slot_count} key={key:?} clock={clock:.3} window={window:.3}s calls_per_s={:.1} phase_rate_per_s={:.4} active_now={} max_age={:.3} rise_slope={slope:.2} ({}) duration={:.2} mode={} owner=[{:.1},{:.1},{:.1}]",
        slot.command.opcode,
        track.calls as f32 / window,
        track.phase_travel / window,
        frames.iter().filter(|frame| frame.active).count(),
        track.max_age,
        if slot.command.opcode == FxOpcode::Op8 { "units/s, age in s" } else { "units/life, age normalized" },
        slot.duration_seconds,
        slot.time_mode,
        slot.world_from_effect[0][3],
        slot.world_from_effect[1][3],
        slot.world_from_effect[2][3],
    );
    *track = FxSpeedDiagnosticTrack {
        window_start: Some(clock),
        last_phase: track.last_phase,
        ..FxSpeedDiagnosticTrack::default()
    };
}

fn ambient_effect_phase(
    time_mode: u32,
    header_flags: u32,
    elapsed_seconds: f32,
    duration_seconds: f32,
) -> Option<f32> {
    if !elapsed_seconds.is_finite()
        || elapsed_seconds < 0.0
        || !duration_seconds.is_finite()
        || duration_seconds < 0.0
    {
        return None;
    }
    let mut phase = match time_mode {
        0 => 0.0,
        // The native phase stays raw through the optional 0x200/0x20
        // transforms; the command-level 0x8120 path clamps only afterward.
        1 if duration_seconds > 0.0 => elapsed_seconds / duration_seconds,
        2 if duration_seconds > 0.0 => {
            elapsed_seconds.rem_euclid(duration_seconds) / duration_seconds
        }
        _ => return None,
    };
    if header_flags & 0x200 != 0 && duration_seconds > 0.0 {
        phase *= elapsed_seconds / duration_seconds;
    }
    if header_flags & 0x20 != 0 {
        phase = if phase >= 0.5 {
            (1.0 - phase) * 2.0
        } else {
            phase * 2.0
        };
    }
    Some(phase)
}

fn rotate_unit_vector(value: [f32; 3], rotation: [f32; 4]) -> [f32; 3] {
    let [x, y, z, w] = rotation;
    let tx = 2.0 * (y * value[2] - z * value[1]);
    let ty = 2.0 * (z * value[0] - x * value[2]);
    let tz = 2.0 * (x * value[1] - y * value[0]);
    [
        value[0] + w * tx + (y * tz - z * ty),
        value[1] + w * ty + (z * tx - x * tz),
        value[2] + w * tz + (x * ty - y * tx),
    ]
}

fn multiply_unit_quaternions(left: [f32; 4], right: [f32; 4]) -> [f32; 4] {
    let [lx, ly, lz, lw] = left;
    let [rx, ry, rz, rw] = right;
    [
        lw * rx + lx * rw + ly * rz - lz * ry,
        lw * ry - lx * rz + ly * rw + lz * rx,
        lw * rz + lx * ry - ly * rx + lz * rw,
        lw * rw - lx * rx - ly * ry - lz * rz,
    ]
}

/// Projects the mission terrain plus every MSH component of the selected roots
/// into one shared world-space mesh.
///
/// Terrain resolves its packed low-byte base and high-byte overlay through
/// map-local `Land1.wea`, then pairs each layer with its `Land2.wea`
/// microtexture and type-18 UV stream. Type-14 alpha remains a continuous
/// interpolated overlay mask. MSH component hierarchy, animation sampling,
/// lightmaps, and gameplay visibility are handled by the preview bridge below.

fn static_preview_node_times(
    node_count: usize,
    bindings: &[PreparedControlNodeBinding],
) -> Result<Vec<Option<AnimationTime>>, String> {
    let mut node_times = vec![Some(AnimationTime(0.0)); node_count];
    for binding in bindings {
        // Disabled rows are filtered while loading CTLD, but preserve the
        // native guard here in case a caller constructs MissionAssets itself.
        if binding.flags & 4 != 0 {
            continue;
        }
        if binding.node_index >= node_count {
            return Err(format!(
                "control binding node {} is outside model node count {node_count}",
                binding.node_index
            ));
        }
        if !binding.frame_a.is_finite()
            || !binding.frame_b.is_finite()
            || !binding.initial_blend.is_finite()
            || binding.frame_a < 0.0
            || binding.frame_b < 0.0
        {
            return Err(format!(
                "control binding for node {} contains an invalid frame or blend",
                binding.node_index
            ));
        }

        let mut blend = binding.initial_blend;
        if binding.flags & 1 != 0 {
            if blend > 1.0 {
                blend -= 1.0;
            }
            if blend < 0.0 {
                blend += 1.0;
            }
        } else {
            blend = blend.clamp(0.0, 1.0);
        }
        if binding.flags & 2 != 0 {
            blend = 1.0 - blend;
        }
        let sample_time = (1.0 - blend) * binding.frame_a + blend * binding.frame_b;
        if !sample_time.is_finite() || sample_time < 0.0 {
            return Err(format!(
                "control binding for node {} produced a negative or non-finite sample time unsupported by the static sampler",
                binding.node_index
            ));
        }
        // Source order is significant: native initialization writes each
        // enabled row in turn, so a later row for the same node wins.
        node_times[binding.node_index] = Some(AnimationTime(sample_time));
    }
    Ok(node_times)
}

fn static_preview_component_pose_buffer(
    model: &ModelAsset,
    bindings: &[PreparedControlNodeBinding],
    static_animation_frame: Option<u16>,
) -> Result<Option<NodePoseBuffer>, String> {
    if let Some(frame) = static_animation_frame {
        return Ok(node38_sampled_hierarchy(model, frame));
    }
    let node_times = static_preview_node_times(model.node_count, bindings)?;
    Ok(node38_sampled_hierarchy_at_times(model, &node_times)
        .or_else(|| node38_fallback_hierarchy(model)))
}

fn initial_control_gate_values(control: &PreparedComponentControl) -> Vec<Option<f32>> {
    control
        .typed_records
        .iter()
        .filter(|record| record.tag == 21)
        .map(|record| match &record.gate_provider {
            PreparedControlGateProvider::Resolved {
                initial_type1_value,
                ..
            } if initial_type1_value.is_finite() => Some(*initial_type1_value),
            _ => None,
        })
        .collect()
}

fn control_clock_ms_for_frame(target_ms: u32, frame_index: u64, target_frames: u64) -> u32 {
    if target_frames <= 1 {
        return target_ms;
    }
    let last_frame = u128::from(target_frames - 1);
    let frame = u128::from(frame_index).min(last_frame);
    ((u128::from(target_ms) * frame) / last_frame) as u32
}

fn replay_environment_delta_seconds(last_applied_ms: u32, current_ms: u32) -> f32 {
    current_ms.saturating_sub(last_applied_ms) as f32 / 1_000.0
}

fn control_clock_mode_label(target_ms: Option<u32>) -> String {
    match target_ms {
        None => "realtime".to_string(),
        Some(0) => "fixed-0ms".to_string(),
        Some(target_ms) => format!("ramp-0-to-{target_ms}ms"),
    }
}

fn write_readback_sequence_frame(
    directory: &Path,
    frame_index: u64,
    control_clock_ms: u32,
    artifact: &VulkanReadbackArtifact,
) -> Result<PathBuf, String> {
    std::fs::create_dir_all(directory).map_err(|error| {
        format!(
            "create readback sequence directory {}: {error}",
            directory.display()
        )
    })?;
    let path = directory.join(format!(
        "frame-{frame_index:06}-clock-{control_clock_ms:010}ms-{}x{}.rgba",
        artifact.width, artifact.height,
    ));
    let mut file = std::fs::OpenOptions::new()
        .write(true)
        .create_new(true)
        .open(&path)
        .map_err(|error| format!("create readback frame {}: {error}", path.display()))?;
    file.write_all(&artifact.bytes)
        .map_err(|error| format!("write readback frame {}: {error}", path.display()))?;
    Ok(path)
}

fn quaternion_yaw_z_degrees(rotation: [f32; 4]) -> Option<f32> {
    if !rotation.iter().all(|value| value.is_finite()) {
        return None;
    }
    let [x, y, z, w] = rotation;
    let radians = (2.0 * (w * z + x * y)).atan2(1.0 - 2.0 * (y * y + z * z));
    radians.is_finite().then_some(radians.to_degrees())
}

fn emit_control_animation_capture_diagnostics(
    instances: &[Vec<Option<ControlAnimationInstance>>],
    pose_buffers: &[Vec<Option<NodePoseBuffer>>],
    control_clock_ms: u32,
) {
    for (object_index, components) in instances.iter().enumerate() {
        for (component_index, instance) in components.iter().enumerate() {
            let Some(instance) = instance.as_ref() else {
                continue;
            };
            let mut gate_index = 0;
            for record in instance
                .control
                .typed_records
                .iter()
                .filter(|record| record.tag == 21)
            {
                let mapped_row = record
                    .values
                    .first()
                    .and_then(|row| usize::try_from(*row).ok());
                let timeline = mapped_row.and_then(|row| instance.control.timeline_rows.get(row));
                let node_index = timeline.map(|row| row.node_index);
                let sampled_time = node_index
                    .and_then(|node| instance.last_sampled_node_times.get(node))
                    .copied()
                    .flatten();
                let pose = pose_buffers
                    .get(object_index)
                    .and_then(|items| items.get(component_index))
                    .and_then(Option::as_ref)
                    .and_then(|hierarchy| node_index.and_then(|node| hierarchy.poses.get(node)));
                let rotation = pose.map(|pose| pose.rotation);
                let yaw_z_degrees = rotation.and_then(quaternion_yaw_z_degrees);
                let gate_value = instance.gate_values.get(gate_index).copied().flatten();
                eprintln!(
                    "control_animation_capture object={object_index} component={component_index} clock_ms={control_clock_ms} gate_value={gate_value:?} gate_provider={:?} row={mapped_row:?} node={node_index:?} sampled_time={sampled_time:?} rotation={rotation:?} yaw_z_degrees={yaw_z_degrees:?}",
                    record.gate_provider,
                );
                gate_index += 1;
            }
        }
    }
}

fn update_control_animation_pose_buffers(
    instances: &mut [Vec<Option<ControlAnimationInstance>>],
    pose_buffers: &mut [Vec<Option<NodePoseBuffer>>],
    native_clock_ms: u32,
) -> Result<(), String> {
    for (object_index, components) in instances.iter_mut().enumerate() {
        let Some(object_pose_buffers) = pose_buffers.get_mut(object_index) else {
            continue;
        };
        for (component_index, instance) in components.iter_mut().enumerate() {
            let Some(instance) = instance.as_mut() else {
                continue;
            };
            let node_times: Vec<Option<AnimationTime>> = match sample_control_node_times(
                &instance.control,
                native_clock_ms,
                &instance.gate_values,
                &mut instance.state,
            ) {
                Ok(times) => {
                    instance.last_sampled_node_times = times.clone();
                    times
                        .into_iter()
                        .map(|time| time.map(AnimationTime))
                        .collect()
                }
                Err(
                    error @ (ControlSamplingError::UnsupportedTag21Mode { .. }
                    | ControlSamplingError::UnsupportedVariableMapping { .. }
                    | ControlSamplingError::MissingGateProvider { .. }
                    | ControlSamplingError::GateProviderKeyOutOfRange { .. }
                    | ControlSamplingError::MissingGateProviderValue { .. }
                    | ControlSamplingError::GateProviderCountMismatch { .. }),
                ) => {
                    if !instance.reported_unsupported_fallback {
                        eprintln!(
                            "control_animation_fallback object={object_index} component={component_index} error={error:?}"
                        );
                        instance.reported_unsupported_fallback = true;
                    }
                    let fallback_times = static_preview_node_times(
                        instance.control.model_node_count,
                        &instance.control.bindings,
                    )
                    .map_err(|fallback| {
                        format!(
                            "control animation fallback for object {object_index} component {component_index}: {fallback}"
                        )
                    })?;
                    instance.last_sampled_node_times = fallback_times
                        .iter()
                        .map(|time| time.map(|time| time.0))
                        .collect();
                    fallback_times
                }
                Err(error) => {
                    return Err(format!(
                        "control animation sample for object {object_index} component {component_index}: {error:?}"
                    ));
                }
            };
            let hierarchy = node38_sampled_hierarchy_at_times(&instance.model, &node_times)
                .or_else(|| node38_fallback_hierarchy(&instance.model));
            if let Some(hierarchy) = hierarchy {
                if let Some(pose_buffer) = object_pose_buffers.get_mut(component_index) {
                    *pose_buffer = Some(hierarchy);
                }
            }
        }
    }
    Ok(())
}

fn control_tree_chain_has_tag21(
    component_index: usize,
    tree: Option<&[fparkan_prototype::UnitComponentTreeNode]>,
    controls: &[Option<PreparedComponentControl>],
) -> bool {
    let mut current = Some(component_index);
    let mut remaining = controls.len();
    while let Some(index) = current {
        if controls
            .get(index)
            .and_then(Option::as_ref)
            .is_some_and(|control| control.typed_records.iter().any(|record| record.tag == 21))
        {
            return true;
        }
        if remaining == 0 {
            return false;
        }
        remaining -= 1;
        current = tree
            .and_then(|nodes| nodes.get(index))
            .and_then(|node| node.parent_index);
    }
    false
}

fn update_dynamic_component_geometry(
    geometry: &[Vec<Option<DynamicComponentGeometry>>],
    pose_buffers: &[Vec<Option<NodePoseBuffer>>],
    mount_poses: &mut [Vec<Option<VulkanNodePose>>],
    mesh: &mut VulkanStaticMesh,
) -> Result<(), String> {
    let identity_pose = VulkanNodePose {
        translation: [0.0; 3],
        rotation: [0.0, 0.0, 0.0, 1.0],
    };
    for (object_index, components) in geometry.iter().enumerate() {
        for (component_index, component) in components.iter().enumerate() {
            let Some(component) = component else {
                continue;
            };
            if let Some((parent_index, socket)) = component.parent_mount {
                let parent_mounted = mount_poses
                    .get(object_index)
                    .and_then(|items| items.get(parent_index))
                    .ok_or_else(|| {
                        format!("dynamic component {object_index}:{component_index} has no parent mount slot")
                    })?
                    .is_some();
                let parent_hierarchy = pose_buffers
                    .get(object_index)
                    .and_then(|items| items.get(parent_index))
                    .and_then(Option::as_ref)
                    .ok_or_else(|| {
                        format!(
                            "dynamic component {object_index}:{component_index} has no parent pose"
                        )
                    })?;
                let parent_socket = if parent_mounted {
                    node38_pose_relative_to_root_from_hierarchy(parent_hierarchy, socket)
                } else {
                    node38_pose_from_hierarchy(parent_hierarchy, socket)
                }
                .ok_or_else(|| {
                    format!("dynamic component {object_index}:{component_index} parent socket {socket} is unavailable")
                })?;
                let parent_root = mount_poses
                    .get(object_index)
                    .and_then(|items| items.get(parent_index))
                    .copied()
                    .flatten()
                    .unwrap_or(identity_pose);
                let mount = mount_poses
                    .get_mut(object_index)
                    .and_then(|items| items.get_mut(component_index))
                    .ok_or_else(|| {
                        format!(
                            "dynamic component {object_index}:{component_index} has no mount slot"
                        )
                    })?;
                *mount = Some(compose_unit_pose(parent_root, parent_socket));
            }
            let hierarchy = pose_buffers
                .get(object_index)
                .and_then(|items| items.get(component_index))
                .and_then(Option::as_ref)
                .ok_or_else(|| {
                    format!(
                        "dynamic component {object_index}:{component_index} has no sampled pose"
                    )
                })?;
            let mount = mount_poses
                .get(object_index)
                .and_then(|items| items.get(component_index))
                .copied()
                .flatten();
            let projected = match mount {
                Some(mount) => {
                    project_msh_to_static_mesh_in_world_space_with_node_pose_buffer_and_mount(
                        &component.model,
                        component.root_transform,
                        component.owner_scale,
                        hierarchy,
                        mount,
                    )
                }
                None => project_msh_to_static_mesh_in_world_space_with_node_pose_buffer(
                    &component.model,
                    component.root_transform,
                    component.owner_scale,
                    hierarchy,
                ),
            }
            .map_err(|error| {
                format!("reproject dynamic component {object_index}:{component_index}: {error}")
            })?;
            if projected.vertices.len() != component.vertex_count {
                return Err(format!(
                    "dynamic component {object_index}:{component_index} changed vertex count from {} to {}",
                    component.vertex_count,
                    projected.vertices.len()
                ));
            }
            let end = component
                .vertex_start
                .checked_add(component.vertex_count)
                .filter(|end| *end <= mesh.vertices.len())
                .ok_or_else(|| {
                    format!(
                        "dynamic component {object_index}:{component_index} vertex span is invalid"
                    )
                })?;
            mesh.vertices[component.vertex_start..end].copy_from_slice(&projected.vertices);
        }
    }
    Ok(())
}

struct MissionBasementFootprint {
    object_index: usize,
    outer: Vec<[f32; 2]>,
    inner: Vec<[f32; 3]>,
    flatten_inner_to_mean_outer_z: bool,
}

fn apply_basement_placement_deltas(
    roots: &[MissionObjectDraft],
    footprints: &[MissionBasementFootprint],
    placements: &[BasementPlacement],
) -> Result<Vec<MissionObjectDraft>, String> {
    if footprints.len() != placements.len() {
        return Err("basement placement results are not aligned with mission roots".to_string());
    }
    let mut adjusted_roots = roots.to_vec();
    for (footprint, placement) in footprints.iter().zip(placements) {
        let root = adjusted_roots
            .get_mut(footprint.object_index)
            .ok_or_else(|| "basement footprint references an unknown mission root".to_string())?;
        root.position = root.root_position_with_basement_delta(placement.placement_delta);
    }
    Ok(adjusted_roots)
}

fn mission_basement_footprints(
    assets: &MissionAssets,
    roots: &[MissionObjectDraft],
) -> Result<Vec<MissionBasementFootprint>, String> {
    let mut footprints = Vec::new();
    for (object_index, mission_root) in roots.iter().enumerate() {
        let Some(mode) = mission_root.basement_placement_mode() else {
            continue;
        };
        let Some(component_bas) = assets
            .object_component_bas
            .get(object_index)
            .and_then(|components| components.first())
            .and_then(Option::as_ref)
        else {
            continue;
        };
        let geometry = &component_bas.geometry;
        let bas_label = format!(
            "{}:{}",
            component_bas.source.archive.as_str(),
            String::from_utf8_lossy(&component_bas.source.name.0)
        );
        // shortcut: the installed Iron Strategy corpus has one inner and one
        // outer ring per eligible DAT. Native iterates both arrays, so reject
        // unsupported multiplicity until the multi-ring semantics are ported.
        if geometry.first.len() != 1 || geometry.second.len() != 1 {
            return Err(format!(
                "eligible mission object {object_index} from {bas_label} has {} inner and {} outer BAS rings; one of each is supported",
                geometry.first.len(),
                geometry.second.len()
            ));
        }
        let transform = LegacyIron3dEulerTransform {
            translation: mission_root.position,
            orientation_radians: mission_root.orientation_raw,
        };
        let transform_points = |points: &[[f32; 3]], ring_name: &str| {
            let mut transformed_points = Vec::with_capacity(points.len());
            for &point in points {
                let transformed = transform
                    .try_transform_scaled_point(point, mission_root.scale)
                    .ok_or_else(|| {
                        format!(
                            "building BAS {ring_name} ring on mission object {object_index} from {bas_label} has a non-finite transformed point"
                        )
                    })?;
                transformed_points.push(transformed);
            }
            Ok::<_, String>(transformed_points)
        };
        let inner_record = &geometry.first[0];
        let outer_record = &geometry.second[0];
        for (ring_name, declared_count, points) in [
            ("inner", inner_record.declared_count, &inner_record.points),
            ("outer", outer_record.declared_count, &outer_record.points),
        ] {
            let expected_point_count = usize::try_from(declared_count)
                .ok()
                .and_then(|count| count.checked_add(1))
                .ok_or_else(|| format!("building BAS {ring_name} count overflows: {bas_label}"))?;
            if usize::try_from(declared_count).unwrap_or(0) < 3
                || points.len() != expected_point_count
            {
                return Err(format!(
                    "building BAS {ring_name} ring on mission object {object_index} from {bas_label} has count {declared_count} and {} points",
                    points.len()
                ));
            }
        }
        let inner = transform_points(&inner_record.points, "inner")?;
        let outer_3d = transform_points(&outer_record.points, "outer")?;
        footprints.push(MissionBasementFootprint {
            object_index,
            outer: outer_3d.iter().map(|point| [point[0], point[1]]).collect(),
            inner,
            flatten_inner_to_mean_outer_z: mode == BasementPlacementMode::FlattenInnerAndAdjustRoot,
        });
    }
    Ok(footprints)
}

fn interpolate_static_terrain_vertex(
    position: [f32; 3],
    source: [VulkanStaticVertex; 3],
) -> Result<VulkanStaticVertex, String> {
    let point = [f64::from(position[0]), f64::from(position[1])];
    let a = [
        f64::from(source[0].position[0]),
        f64::from(source[0].position[1]),
    ];
    let b = [
        f64::from(source[1].position[0]),
        f64::from(source[1].position[1]),
    ];
    let c = [
        f64::from(source[2].position[0]),
        f64::from(source[2].position[1]),
    ];
    let denominator = (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0]);
    if !denominator.is_finite() || denominator.abs() <= 1.0e-10 {
        return Err("terrain source triangle has no stable XY barycentric coordinates".to_string());
    }
    let second_weight =
        ((point[0] - a[0]) * (c[1] - a[1]) - (point[1] - a[1]) * (c[0] - a[0])) / denominator;
    let third_weight =
        ((b[0] - a[0]) * (point[1] - a[1]) - (b[1] - a[1]) * (point[0] - a[0])) / denominator;
    let weights = [
        1.0 - second_weight - third_weight,
        second_weight,
        third_weight,
    ];
    if !weights.iter().all(|weight| weight.is_finite()) {
        return Err("terrain split vertex has invalid barycentric coordinates".to_string());
    }
    let blend2 = |values: [[f32; 2]; 3]| {
        [
            (0..3)
                .map(|index| values[index][0] * weights[index] as f32)
                .sum(),
            (0..3)
                .map(|index| values[index][1] * weights[index] as f32)
                .sum(),
        ]
    };
    let blend3 = |values: [[f32; 3]; 3]| {
        std::array::from_fn(|axis| {
            (0..3)
                .map(|index| values[index][axis] * weights[index] as f32)
                .sum()
        })
    };
    let overlay_alpha = (0..3)
        .map(|index| source[index].overlay_alpha * weights[index] as f32)
        .sum::<f32>();
    if !overlay_alpha.is_finite() {
        return Err(format!(
            "terrain split vertex overlay alpha is non-finite: position={position:?}, weights={weights:?}, source_position={:?}, source_alpha={:?}, result={overlay_alpha}",
            source.map(|vertex| vertex.position),
            source.map(|vertex| vertex.overlay_alpha)
        ));
    }
    const OVERLAY_ALPHA_ROUNDING_TOLERANCE: f32 = 1.0e-5;
    if overlay_alpha < -OVERLAY_ALPHA_ROUNDING_TOLERANCE
        || overlay_alpha > 1.0 + OVERLAY_ALPHA_ROUNDING_TOLERANCE
    {
        return Err(format!(
            "terrain split vertex overlay alpha exceeds barycentric rounding tolerance: position={position:?}, weights={weights:?}, source_position={:?}, source_alpha={:?}, result={overlay_alpha}",
            source.map(|vertex| vertex.position),
            source.map(|vertex| vertex.overlay_alpha)
        ));
    }
    let vertex = VulkanStaticVertex {
        position,
        color: blend3(source.map(|vertex| vertex.color)),
        normal: blend3(source.map(|vertex| vertex.normal)),
        uv: blend2(source.map(|vertex| vertex.uv)),
        detail_uv: blend2(source.map(|vertex| vertex.detail_uv)),
        overlay_alpha: overlay_alpha.clamp(0.0, 1.0),
    };
    if !vertex
        .position
        .iter()
        .chain(vertex.color.iter())
        .chain(vertex.normal.iter())
        .chain(vertex.uv.iter())
        .chain(vertex.detail_uv.iter())
        .chain(std::iter::once(&vertex.overlay_alpha))
        .all(|value| value.is_finite())
    {
        return Err(
            "terrain split vertex contains a non-finite interpolated attribute".to_string(),
        );
    }
    Ok(vertex)
}

fn project_basement_foundation(
    terrain: &fparkan_terrain_format::LandMeshDocument,
    source_mesh: &VulkanStaticMesh,
    foundation: &mut BasementFoundation,
) -> Result<(VulkanStaticMesh, Vec<ShadowTriangle>), String> {
    let pipeline_state = source_mesh
        .draw_ranges
        .first()
        .map(|range| range.pipeline_state)
        .ok_or_else(|| "terrain source mesh has no LOD0 draw ranges".to_string())?;
    let (normals, uv0_words) = canonicalize_basement_band_vertices(foundation)?;
    let mut mesh = VulkanStaticMesh {
        vertices: Vec::new(),
        indices: Vec::new(),
        draw_ranges: Vec::new(),
    };
    let mut shadow_receivers = Vec::with_capacity(foundation.fragments.len());

    for (fragment_index, fragment) in foundation.fragments.iter().enumerate() {
        let (material_index, base_only, vertices) = match fragment.source_face {
            Some(face_index) => {
                let face = terrain.faces.get(face_index).ok_or_else(|| {
                    format!("foundation fragment references unknown terrain face {face_index}")
                })?;
                if face.flags != fragment.surface_mask {
                    return Err(format!(
                        "foundation fragment for terrain face {face_index} changed its surface mask"
                    ));
                }
                let source_vertices: [VulkanStaticVertex; 3] = face
                    .vertices
                    .map(|vertex| {
                        source_mesh
                            .vertices
                            .get(usize::from(vertex))
                            .copied()
                            .ok_or_else(|| {
                                format!(
                                    "terrain face {face_index} references an unknown projected vertex"
                                )
                            })
                    })
                    .into_iter()
                    .collect::<Result<Vec<_>, _>>()?
                    .try_into()
                    .map_err(|_| "terrain face did not have three vertices".to_string())?;
                let vertices = fragment
                    .positions
                    .map(|position| {
                        source_vertices
                            .iter()
                            .find(|vertex| vertex.position == position)
                            .copied()
                            .map(Ok)
                            .unwrap_or_else(|| {
                                interpolate_static_terrain_vertex(position, source_vertices)
                            })
                    })
                    .into_iter()
                    .collect::<Result<Vec<_>, _>>()?
                    .try_into()
                    .map_err(|_| {
                        "foundation source fragment did not have three vertices".to_string()
                    })?;
                (
                    face.material_tag,
                    fragment.surface_mask.0 & 0x400 == 0,
                    vertices,
                )
            }
            None => {
                let fragment_normals = normals
                    .get(fragment_index)
                    .and_then(Option::as_ref)
                    .ok_or_else(|| "basement band face has no native vertex normals".to_string())?;
                let fragment_uv0_words = uv0_words
                    .get(fragment_index)
                    .and_then(Option::as_ref)
                    .ok_or_else(|| "basement band face lost its original UV words".to_string())?;
                let vertices = basement_band_vertices(
                    fragment.positions,
                    fragment_uv0_words,
                    fragment_normals,
                );
                (0xff00, true, vertices)
            }
        };

        let first_index = u32::try_from(mesh.indices.len())
            .map_err(|_| "basement terrain index buffer exceeds u32".to_string())?;
        for vertex in vertices {
            let index = u32::try_from(mesh.vertices.len())
                .map_err(|_| "basement terrain vertex buffer exceeds u32".to_string())?;
            mesh.vertices.push(vertex);
            mesh.indices.push(index);
        }
        if let Some(range) = mesh.draw_ranges.last_mut().filter(|range| {
            range.material_index == material_index && range.terrain_base_only == base_only
        }) {
            range.index_count = range
                .index_count
                .checked_add(3)
                .ok_or_else(|| "basement terrain draw range exceeds u32".to_string())?;
        } else {
            mesh.draw_ranges.push(VulkanStaticDrawRange {
                first_index,
                index_count: 3,
                material_index,
                lightmap_index: u8::MAX,
                batch_flags: 0,
                pipeline_state,
                terrain_base_only: base_only,
                alpha_test_reference: VulkanStaticDrawRange::NATIVE_DEFAULT_ALPHA_TEST_REFERENCE,
            });
        }
        shadow_receivers.push(shadow_triangle(fragment.positions, fragment.surface_mask.0));
    }

    Ok((mesh, shadow_receivers))
}

fn prepare_static_terrain_geometry(
    terrain: &fparkan_terrain_format::LandMeshDocument,
    source_mesh: VulkanStaticMesh,
    terrain_world: &TerrainWorld,
    foundation: Option<BasementFoundation>,
) -> Result<(VulkanStaticMesh, Vec<ShadowTriangle>, TerrainWorld), String> {
    let Some(mut foundation) = foundation else {
        return Ok((
            source_mesh,
            terrain_shadow_receivers(terrain)?,
            terrain_world.clone(),
        ));
    };
    let (mesh, shadow_receivers) =
        project_basement_foundation(terrain, &source_mesh, &mut foundation)?;
    let terrain_query = terrain_world
        .clone()
        .with_basement_foundation(foundation)
        .map_err(|error| format!("install canonical terrain query surfaces: {error}"))?;
    Ok((mesh, shadow_receivers, terrain_query))
}

#[derive(Clone, Copy, Debug)]
struct BasementBandVertex {
    position: [f32; 3],
    uv0: [i16; 2],
    // The native callback leaves UV1 unwritten; zero is a deterministic
    // assumption for matching generated vertices and is not native parity.
    detail_uv: [i16; 2],
    alpha: f32,
}

#[derive(Clone, Copy, Debug)]
struct BasementBandVertexGroup {
    position: [f32; 3],
    uv0: [i16; 2],
    detail_uv: [i16; 2],
    alpha: f32,
    face_normal_sum: [i64; 3],
}

fn canonicalize_basement_band_vertices(
    foundation: &mut BasementFoundation,
) -> Result<(Vec<Option<[[f32; 3]; 3]>>, Vec<Option<[[i16; 2]; 3]>>), String> {
    let mut group_ids_by_fragment = vec![None; foundation.fragments.len()];
    let mut uv0_words_by_fragment = vec![None; foundation.fragments.len()];
    let mut groups = Vec::<BasementBandVertexGroup>::new();
    let mut buckets = HashMap::<(i32, i32, i16, i16), Vec<usize>>::new();

    // shortcut: installed-corpus probing found no exact UV0 weld key between
    // generated bands and clipped source fragments. Extend the index to source
    // vertices if a future corpus reaches that key.
    for (fragment_index, fragment) in foundation.fragments.iter_mut().enumerate() {
        if fragment.source_face.is_some() {
            continue;
        }
        // Preserve the input UV words: canonicalizing a welded position can
        // otherwise change this triangle's per-face UV origin.
        let vertices = basement_band_uv_vertices(fragment.positions)?;
        let mut group_ids = [0_usize; 3];
        let mut uv0_words = [[0_i16; 2]; 3];
        for (corner, vertex) in vertices.into_iter().enumerate() {
            uv0_words[corner] = vertex.uv0;
            let cell = basement_vertex_cell(vertex.position)?;
            let mut candidates = Vec::new();
            for dx in -1..=1 {
                for dy in -1..=1 {
                    let (Some(x), Some(y)) = (cell.0.checked_add(dx), cell.1.checked_add(dy))
                    else {
                        continue;
                    };
                    if let Some(bucket) = buckets.get(&(x, y, vertex.uv0[0], vertex.uv0[1])) {
                        candidates.extend(bucket.iter().copied());
                    }
                }
            }
            candidates.sort_unstable();
            let group_index = candidates
                .into_iter()
                .find(|&index| {
                    let existing = groups[index];
                    existing.uv0 == vertex.uv0
                        && existing.detail_uv == vertex.detail_uv
                        && existing.alpha.to_bits() == vertex.alpha.to_bits()
                        && basement_vertex_xy_distance(existing.position, vertex.position) < 0.01
                })
                .unwrap_or_else(|| {
                    let index = groups.len();
                    groups.push(BasementBandVertexGroup {
                        position: vertex.position,
                        uv0: vertex.uv0,
                        detail_uv: vertex.detail_uv,
                        alpha: vertex.alpha,
                        face_normal_sum: [0; 3],
                    });
                    buckets
                        .entry((cell.0, cell.1, vertex.uv0[0], vertex.uv0[1]))
                        .or_default()
                        .push(index);
                    index
                });
            fragment.positions[corner] = groups[group_index].position;
            group_ids[corner] = group_index;
        }
        group_ids_by_fragment[fragment_index] = Some(group_ids);
        uv0_words_by_fragment[fragment_index] = Some(uv0_words);
    }

    for (fragment_index, fragment) in foundation.fragments.iter().enumerate() {
        if fragment.source_face.is_some() {
            continue;
        }
        let Some(face_normal) = packed_basement_face_normal(fragment.positions)? else {
            continue;
        };
        let group_ids = group_ids_by_fragment[fragment_index]
            .ok_or_else(|| "basement band face has no welded vertex groups".to_string())?;
        // The native normal postpass visits each indexed face once per vertex,
        // even if malformed geometry gives two corners the same vertex index.
        for group_index in group_ids.into_iter().collect::<HashSet<_>>() {
            for axis in 0..3 {
                groups[group_index].face_normal_sum[axis] += i64::from(face_normal[axis]);
            }
        }
    }

    let normalized = groups
        .iter()
        .map(|group| normalized_native_vertex_normal(group.face_normal_sum))
        .collect::<Result<Vec<_>, _>>()?;
    Ok((
        group_ids_by_fragment
            .into_iter()
            .map(|group_ids| group_ids.map(|ids| ids.map(|group| normalized[group])))
            .collect(),
        uv0_words_by_fragment,
    ))
}

fn basement_vertex_cell(position: [f32; 3]) -> Result<(i32, i32), String> {
    let x = (position[0] / 0.01).floor();
    let y = (position[1] / 0.01).floor();
    if !x.is_finite()
        || !y.is_finite()
        || x < i32::MIN as f32
        || x > i32::MAX as f32
        || y < i32::MIN as f32
        || y > i32::MAX as f32
    {
        return Err("basement band vertex is outside the native weld grid".to_string());
    }
    Ok((x as i32, y as i32))
}

fn basement_vertex_xy_distance(left: [f32; 3], right: [f32; 3]) -> f32 {
    ((left[0] - right[0]).powi(2) + (left[1] - right[1]).powi(2)).sqrt()
}

fn basement_band_uv_vertices(positions: [[f32; 3]; 3]) -> Result<[BasementBandVertex; 3], String> {
    let raw_uv = positions.map(|point| [point[0] * 0.066_f32, point[1] * 0.066_f32]);
    if !raw_uv.iter().flatten().all(|value| value.is_finite()) {
        return Err("basement band UV is non-finite".to_string());
    }
    let origin = std::array::from_fn::<_, 2, _>(|axis| {
        raw_uv
            .iter()
            .map(|uv| uv[axis])
            .fold(f32::INFINITY, f32::min)
            .floor()
    });
    let mut result = [BasementBandVertex {
        position: [0.0; 3],
        uv0: [0; 2],
        detail_uv: [0; 2],
        alpha: 1.0,
    }; 3];
    for index in 0..3 {
        let mut uv0 = [0_i16; 2];
        for axis in 0..2 {
            let scaled = ((raw_uv[index][axis] - origin[axis]) * 1024.0_f32).round_ties_even();
            if !scaled.is_finite() || scaled < i64::MIN as f32 || scaled > i64::MAX as f32 {
                return Err("basement band UV exceeds the native conversion range".to_string());
            }
            // Native FISTP stores the low signed 16-bit word from its integer result.
            uv0[axis] = (scaled as i64) as i16;
        }
        result[index] = BasementBandVertex {
            position: positions[index],
            uv0,
            detail_uv: [0; 2],
            alpha: 1.0,
        };
    }
    Ok(result)
}

fn packed_basement_face_normal(positions: [[f32; 3]; 3]) -> Result<Option<[i16; 3]>, String> {
    let [a, b, c] = positions.map(|point| point.map(f64::from));
    let first = [b[0] - a[0], b[1] - a[1], b[2] - a[2]];
    let second = [c[0] - a[0], c[1] - a[1], c[2] - a[2]];
    let cross = [
        first[1] * second[2] - first[2] * second[1],
        first[2] * second[0] - first[0] * second[2],
        first[0] * second[1] - first[1] * second[0],
    ];
    let length = cross.iter().map(|value| value * value).sum::<f64>().sqrt();
    if !length.is_finite() {
        return Err("basement band face normal is non-finite".to_string());
    }
    if length == 0.0 {
        return Ok(None);
    }
    Ok(Some(cross.map(|value| {
        ((value / length * 32767.0).round_ties_even()) as i16
    })))
}

fn normalized_native_vertex_normal(face_normal_sum: [i64; 3]) -> Result<[f32; 3], String> {
    let normal = face_normal_sum.map(|value| value as f64);
    let length = normal.iter().map(|value| value * value).sum::<f64>().sqrt();
    if !length.is_finite() {
        return Err("basement band vertex has a non-finite native face-normal sum".to_string());
    }
    if length == 0.0 {
        return Ok([0.0; 3]);
    }
    Ok(normal.map(|value| {
        let packed = (value / length * 127.0)
            .round_ties_even()
            .clamp(-127.0, 127.0) as i8;
        f32::from(packed) / 128.0
    }))
}

fn basement_band_vertices(
    positions: [[f32; 3]; 3],
    uv0_words: &[[i16; 2]; 3],
    normals: &[[f32; 3]; 3],
) -> [VulkanStaticVertex; 3] {
    std::array::from_fn(|index| VulkanStaticVertex {
        position: positions[index],
        color: [1.0; 3],
        normal: normals[index],
        uv: uv0_words[index].map(|value| f32::from(value) / 1024.0),
        // The native callback leaves the secondary UV words unwritten. The
        // renderer uses zero here as a deterministic assumption; generated
        // faces take the base-only path, so the detail coordinate is not sampled.
        detail_uv: [0.0; 2],
        overlay_alpha: 1.0,
    })
}

fn static_preview_mesh_and_materials(
    assets: &MissionAssets,
    terrain: &TerrainWorld,
    roots: &[MissionObjectDraft],
    legacy_camera: Option<LegacyCameraCapture>,
    static_animation_frame: Option<u16>,
    static_material_phase: Option<u16>,
    root: &std::path::Path,
    land_msh_path: &str,
) -> Result<StaticPreviewScene, String> {
    let terrain_mesh = terrain
        .source_mesh()
        .ok_or_else(|| "runtime terrain does not retain its validated source mesh".to_string())?;
    let mut mesh = VulkanStaticMesh {
        vertices: Vec::new(),
        indices: Vec::new(),
        draw_ranges: Vec::new(),
    };
    let mut native_handedness_by_range = HashMap::new();
    let mut type16_present_ranges = HashSet::new();
    let mut materials = Vec::new();
    let mut material_animations = Vec::new();
    let mut ambient_effect_slots = Vec::new();
    let mut control_point_light_slots = Vec::new();
    let mut effect_documents = HashMap::new();
    let mut effect_materials = HashMap::new();
    let mut component_pose_buffers_by_object = Vec::with_capacity(roots.len());
    let mut component_mount_poses_by_object = Vec::with_capacity(roots.len());
    let mut dynamic_component_geometry_by_object = Vec::with_capacity(roots.len());
    let mut building_collision_bindings = Vec::new();
    let mut collision_models =
        HashMap::<fparkan_assets::AssetId<PreparedModel>, Arc<ModelAsset>>::new();
    let mut control_animation_instances_by_object = Vec::with_capacity(roots.len());
    let mut dynamic_shadow_casters = Vec::new();
    let mut sun_occlusion_range_indices = Vec::new();
    let mut shadow_casters = Vec::new();
    let mut terrain_material_loader = StandaloneWearMaterialLoader::new(root);
    let source_terrain_component = project_land_msh_to_static_mesh_in_world_space(terrain_mesh)
        .map_err(|err| format!("project mission terrain for Vulkan: {err}"))?;
    let footprint_sources = mission_basement_footprints(assets, roots)?;
    let foundation = if footprint_sources.is_empty() {
        None
    } else {
        let footprints = footprint_sources
            .iter()
            .map(|footprint| BasementFootprint {
                outer: &footprint.outer,
                inner: &footprint.inner,
                flatten_inner_to_mean_outer_z: footprint.flatten_inner_to_mean_outer_z,
            })
            .collect::<Vec<_>>();
        Some(
            build_basement_foundations(terrain_mesh, &footprints)
                .map_err(|error| format!("prepare mission basement foundations: {error}"))?,
        )
    };
    let effective_roots = foundation
        .as_ref()
        .map(|foundation| {
            apply_basement_placement_deltas(roots, &footprint_sources, &foundation.placements)
        })
        .transpose()?;
    // Every visual, mounted component, effect, and shadow caster below uses this
    // same root transform, so the native delta is applied once to the hierarchy.
    let roots = effective_roots.as_deref().unwrap_or(roots);
    let (terrain_component, shadow_receivers, terrain_query) = prepare_static_terrain_geometry(
        terrain_mesh,
        source_terrain_component,
        terrain,
        foundation,
    )?;
    let terrain_materials = static_preview_terrain_base_materials(
        &mut terrain_material_loader,
        root,
        land_msh_path,
        &terrain_component,
        &mut materials,
        &mut material_animations,
        static_material_phase,
    )?;
    append_static_preview_component(
        &mut mesh,
        terrain_component,
        &terrain_materials,
        Some(&mut material_animations),
    )?;
    let mut mesh_components = 0;
    for (object_index, mission_root) in roots.iter().enumerate() {
        let visual_ids = assets.visuals_for_object(object_index);
        let records = &mission_root.unit_components;
        let tree = if records.is_empty() {
            None
        } else {
            Some(unit_component_tree(records).map_err(|error| {
                format!("decode unit component tree for mission object {object_index}: {error}")
            })?)
        };
        if let Some(tree) = tree.as_ref() {
            if tree.len() != visual_ids.len() {
                return Err(format!(
                    "mission object {object_index} unit tree has {} records but {} visuals",
                    tree.len(),
                    visual_ids.len()
                ));
            }
        }
        let component_refs = visual_ids
            .iter()
            .map(|visual_id| {
                let visual = assets.visual_by_id(*visual_id).ok_or_else(|| {
                    format!(
                        "static preview root {object_index} references unknown visual {visual_id:?}"
                    )
                })?;
                let model = visual
                    .model_id
                    .map(|model_id| {
                        assets.model_by_id(model_id).ok_or_else(|| {
                            format!(
                                "static preview visual {visual_id:?} references unknown model {model_id:?}"
                            )
                        })
                    })
                    .transpose()?;
                Ok((visual, model))
            })
            .collect::<Result<Vec<_>, String>>()?;
        let component_controls = assets.object_component_controls.get(object_index);
        if component_controls.is_some_and(|controls| controls.len() != component_refs.len()) {
            return Err(format!(
                "mission object {object_index} has {} visuals but {} component controls",
                component_refs.len(),
                component_controls.map_or(0, Vec::len)
            ));
        }
        let root_native_kind = component_refs
            .first()
            .and_then(|(visual, _)| native_shadow_kind(visual.source_type));
        let root_sun_eligible = native_sun_object_kind_eligible(
            component_refs
                .first()
                .and_then(|(visual, _)| visual.source_type),
        );
        let mut root_shadow_triangles = Vec::new();
        let mut root_shadow_spheres = Vec::new();
        let mut root_shadow_sphere_sources = Vec::new();
        let mut root_shadow_draw_range_indices = Vec::new();
        let mut component_mount_poses = vec![None; component_refs.len()];
        let mut component_pose_buffers = vec![None; component_refs.len()];
        let mut dynamic_component_geometry = vec![None; component_refs.len()];
        let mut control_animation_instances = vec![None; component_refs.len()];
        for (component_index, (visual, model)) in component_refs.iter().enumerate() {
            let should_render = tree.as_ref().map_or(true, |_| {
                unit_component_is_visible(component_index, visual.source_type)
            });
            let control = component_controls
                .and_then(|controls| controls.get(component_index))
                .and_then(Option::as_ref);
            let Some(model) = *model else {
                if legacy_camera.is_none() && root_native_kind == Some(3) && should_render {
                    return Err(format!(
                        "building collision object {object_index} component {component_index} has no model"
                    ));
                }
                if component_index == 0 {
                    if let Some(control) = control {
                        append_initial_control_effect_slots(
                            root,
                            mission_root,
                            object_index,
                            component_index,
                            control,
                            None,
                            None,
                            &mut mesh,
                            &mut materials,
                            &mut material_animations,
                            &mut effect_documents,
                            &mut effect_materials,
                            &mut ambient_effect_slots,
                            &mut control_point_light_slots,
                        )?;
                    }
                }
                continue;
            };
            let component_bindings = component_controls
                .and_then(|controls| controls.get(component_index))
                .and_then(Option::as_ref)
                .map_or(&[][..], |control| control.bindings.as_slice());
            if static_animation_frame.is_none() {
                if let Some(control) = control {
                    control_animation_instances[component_index] = Some(ControlAnimationInstance {
                        control: control.clone(),
                        model: model.validated.clone(),
                        gate_values: initial_control_gate_values(control),
                        state: ControlInstanceState::default(),
                        last_sampled_node_times: Vec::new(),
                        reported_unsupported_fallback: false,
                    });
                }
            }
            component_pose_buffers[component_index] = static_preview_component_pose_buffer(
                &model.validated,
                component_bindings,
                static_animation_frame,
            )?;
            let timeline_moves_component = static_animation_frame.is_none()
                && control_tree_chain_has_tag21(
                    component_index,
                    tree.as_deref(),
                    component_controls.map_or(&[][..], |controls| controls.as_slice()),
                );
            // Native AniMesh only resolves global MSH node sockets for EXTO
            // geometry. Internal INTO components use controller/equipment
            // slots, whose `parent_or_link` values are not MSH node indices.
            // Do not ask the MSH hierarchy to resolve hidden internal parts.
            let mount_pose = if should_render {
                if let Some(tree) = tree.as_ref() {
                    let record = records.get(component_index).ok_or_else(|| {
                        format!("unit component {component_index} is outside decoded records")
                    })?;
                    let parent_index = tree[component_index].parent_index;
                    match parent_index {
                        None => None,
                        Some(parent_index) => {
                            let parent_visible = component_refs.get(parent_index).is_some_and(
                                |(parent_visual, _)| {
                                    unit_component_is_visible(
                                        parent_index,
                                        parent_visual.source_type,
                                    )
                                },
                            );
                            if !parent_visible {
                                None
                            } else {
                                let parent_model = component_refs
                                    .get(parent_index)
                                    .and_then(|(_, model)| *model)
                                    .ok_or_else(|| {
                                        format!(
                                            "unit component {component_index} parent {parent_index} has no model for mount socket"
                                        )
                                    })?;
                                let parent_hierarchy = component_pose_buffers
                                    .get(parent_index)
                                    .and_then(Option::as_ref);
                                let parent_is_mounted =
                                    component_mount_poses[parent_index].is_some();
                                let socket =
                                    usize::try_from(record.parent_or_link).map_err(|_| {
                                        format!(
                                            "unit component {component_index} has negative mount socket {}",
                                            record.parent_or_link
                                        )
                                    })?;
                                let parent_socket = match parent_hierarchy {
                                    Some(hierarchy) if parent_is_mounted => {
                                        node38_pose_relative_to_root_from_hierarchy(
                                            hierarchy, socket,
                                        )
                                    }
                                    Some(hierarchy) => {
                                        node38_pose_from_hierarchy(hierarchy, socket)
                                    }
                                    None if parent_is_mounted => node38_pose_relative_to_root(
                                        &parent_model.validated,
                                        static_animation_frame,
                                        socket,
                                    ),
                                    None => node38_pose(
                                        &parent_model.validated,
                                        static_animation_frame,
                                        socket,
                                    ),
                                }
                                .ok_or_else(|| {
                                        format!(
                                            "unit component {component_index} mount socket {socket} is absent from parent {parent_index} (parent source={:?}, node_count={}, slots={}, animation={})",
                                            parent_model.source,
                                            parent_model.validated.node_count,
                                            parent_model.validated.slots.len(),
                                            parent_model.validated.animation.is_some(),
                                        )
                                    })?;
                                let parent_root_pose = component_mount_poses[parent_index]
                                    .unwrap_or(VulkanNodePose {
                                        translation: [0.0; 3],
                                        rotation: [0.0, 0.0, 0.0, 1.0],
                                    });
                                Some(compose_unit_pose(parent_root_pose, parent_socket))
                            }
                        }
                    }
                } else {
                    None
                }
            } else {
                None
            };
            if let Some(mount_pose) = mount_pose {
                component_mount_poses[component_index] = Some(mount_pose);
            }
            // External tree components have a recovered mount pose; flat
            // mission components and the root use the mission pose. Hidden
            // INTO slots use controller links rather than MSH sockets, so
            // their Control owner transform remains unresolved here.
            let owner_pose_available =
                component_index == 0 || tree.is_none() || mount_pose.is_some();
            if owner_pose_available {
                if let Some(control) = control {
                    append_initial_control_effect_slots(
                        root,
                        mission_root,
                        object_index,
                        component_index,
                        control,
                        component_pose_buffers[component_index].as_ref(),
                        mount_pose,
                        &mut mesh,
                        &mut materials,
                        &mut material_animations,
                        &mut effect_documents,
                        &mut effect_materials,
                        &mut ambient_effect_slots,
                        &mut control_point_light_slots,
                    )?;
                }
            }

            let transform = LegacyIron3dEulerTransform {
                translation: mission_root.position,
                orientation_radians: mission_root.orientation_raw,
            };
            if legacy_camera.is_none() && root_native_kind == Some(3) && should_render {
                let shared_model = collision_models
                    .entry(model.id)
                    .or_insert_with(|| Arc::new(model.validated.clone()))
                    .clone();
                building_collision_bindings.push(building_collision_binding(
                    object_index,
                    component_index,
                    format!("{:?}", model.source),
                    shared_model,
                    transform,
                    mission_root.scale,
                    mount_pose.is_some(),
                )?);
            }
            if should_render {
                let pose_buffer = component_pose_buffers[component_index].as_ref();
                let mut component = match (pose_buffer, mount_pose, static_animation_frame) {
                    (Some(poses), Some(mount), _) => {
                        project_msh_to_static_mesh_in_world_space_with_node_pose_buffer_and_mount(
                            &model.validated,
                            transform,
                            mission_root.scale,
                            poses,
                            mount,
                        )
                    }
                    (Some(poses), None, _) => {
                        project_msh_to_static_mesh_in_world_space_with_node_pose_buffer(
                            &model.validated,
                            transform,
                            mission_root.scale,
                            poses,
                        )
                    }
                    (None, Some(mount), Some(frame)) => {
                        project_msh_to_static_mesh_in_world_space_with_node_sampled_poses_and_mount(
                            &model.validated,
                            transform,
                            mission_root.scale,
                            frame,
                            mount,
                        )
                    }
                    (None, Some(mount), None) => {
                        project_msh_to_static_mesh_in_world_space_with_node_fallback_poses_and_mount(
                            &model.validated,
                            transform,
                            mission_root.scale,
                            mount,
                        )
                    }
                    (None, None, Some(frame)) => {
                        project_msh_to_static_mesh_in_world_space_with_node_sampled_poses(
                            &model.validated,
                            transform,
                            mission_root.scale,
                            frame,
                        )
                    }
                    (None, None, None) => {
                        project_msh_to_static_mesh_in_world_space_with_node_fallback_poses(
                            &model.validated,
                            transform,
                            mission_root.scale,
                        )
                    }
                }
                .map_err(|err| format!("project mission MSH for Vulkan: {err}"))?;
                let component_handedness = native_msh_handedness(transform, mission_root.scale);
                for range in &mut component.draw_ranges {
                    range.pipeline_state.cull =
                        native_msh_cull_mode(range.batch_flags, component_handedness);
                }
                let component_shadow_triangles = static_mesh_shadow_triangles(&component);
                if root_native_kind.is_some() {
                    root_shadow_triangles.extend(component_shadow_triangles);
                    let node1_pose = mount_pose.and_then(|_| match pose_buffer {
                        Some(poses) => node38_pose_relative_to_root_from_hierarchy(poses, 1),
                        None => node38_pose_relative_to_root(
                            &model.validated,
                            static_animation_frame,
                            1,
                        ),
                    });
                    if let Some(sphere) = mounted_shadow_sphere(
                        model.validated.bounding_sphere_center,
                        model.validated.bounding_sphere_radius,
                        mount_pose,
                        node1_pose,
                    ) {
                        root_shadow_spheres.push(sphere);
                        root_shadow_sphere_sources.push(DynamicShadowSphereSource {
                            component_index,
                            center: model.validated.bounding_sphere_center,
                            radius: model.validated.bounding_sphere_radius,
                            mounted: mount_pose.is_some(),
                        });
                    }
                }
                let selector_remap = static_preview_component_materials(
                    assets,
                    visual,
                    &component,
                    static_material_phase,
                    &mut materials,
                    &mut material_animations,
                )?;
                let lightmap_textures = static_preview_lightmap_textures(assets, visual)?;
                let range_start = mesh.draw_ranges.len();
                let vertex_start = mesh.vertices.len();
                let vertex_count = component.vertices.len();
                append_static_preview_component_with_lightmaps(
                    &mut mesh,
                    component,
                    &selector_remap,
                    Some(&mut materials),
                    &lightmap_textures,
                    Some(&mut material_animations),
                )?;
                for range_index in range_start..mesh.draw_ranges.len() {
                    native_handedness_by_range.insert(range_index, component_handedness);
                    if model.validated.type16_present {
                        type16_present_ranges.insert(range_index);
                    }
                }
                if root_native_kind.is_some() {
                    root_shadow_draw_range_indices.extend(range_start..mesh.draw_ranges.len());
                }
                if timeline_moves_component {
                    let parent_mount = tree
                        .as_ref()
                        .and_then(|nodes| nodes.get(component_index))
                        .and_then(|node| node.parent_index)
                        .filter(|parent_index| {
                            component_mount_poses[*parent_index].is_some()
                                || component_refs.get(*parent_index).is_some_and(
                                    |(parent_visual, _)| {
                                        unit_component_is_visible(
                                            *parent_index,
                                            parent_visual.source_type,
                                        )
                                    },
                                )
                        })
                        .map(|parent_index| {
                            let socket = usize::try_from(records[component_index].parent_or_link)
                                .expect("mount socket was validated above");
                            (parent_index, socket)
                        });
                    dynamic_component_geometry[component_index] = Some(DynamicComponentGeometry {
                        model: model.validated.clone(),
                        root_transform: transform,
                        owner_scale: mission_root.scale,
                        parent_mount,
                        vertex_start,
                        vertex_count,
                    });
                }
                if root_sun_eligible {
                    sun_occlusion_range_indices.extend(range_start..mesh.draw_ranges.len());
                }
                mesh_components += 1;
            }
        }
        if let Some(native_kind) =
            root_native_kind.filter(|kind| native_shadow_caster_enabled(*kind))
        {
            let caster_id = u32::try_from(shadow_casters.len())
                .map_err(|_| "shadow caster id exceeds u32".to_string())?;
            let root_transform = LegacyIron3dEulerTransform {
                translation: mission_root.position,
                orientation_radians: mission_root.orientation_raw,
            };
            if let Some(caster) = aggregate_shadow_caster(
                caster_id,
                native_kind,
                root_transform,
                mission_root.scale,
                root_shadow_triangles,
                &root_shadow_spheres,
            ) {
                if dynamic_component_geometry.iter().any(Option::is_some) {
                    let component_draw_range_indices = root_shadow_draw_range_indices
                        .into_iter()
                        .filter(|range_index| {
                            mesh.draw_ranges
                                .get(*range_index)
                                .is_some_and(|range| range.index_count != 0)
                        })
                        .collect::<Vec<_>>();
                    if !component_draw_range_indices.is_empty() {
                        dynamic_shadow_casters.push(DynamicShadowCaster {
                            caster_index: shadow_casters.len(),
                            object_index,
                            root_transform,
                            owner_scale: mission_root.scale,
                            initial_sphere: caster.sphere,
                            component_draw_range_indices,
                            component_spheres: root_shadow_sphere_sources.clone(),
                        });
                    }
                }
                shadow_casters.push(caster);
            }
        }
        component_pose_buffers_by_object.push(component_pose_buffers);
        component_mount_poses_by_object.push(component_mount_poses);
        dynamic_component_geometry_by_object.push(dynamic_component_geometry);
        control_animation_instances_by_object.push(control_animation_instances);
    }
    if mesh_components == 0 {
        return Err("selected static preview roots have no mesh-backed visual".to_string());
    }
    let free_camera = if legacy_camera.is_none() {
        Some(FreeFlightCamera::from_mesh_and_terrain(&mesh, terrain)?)
    } else {
        None
    };
    let captured_viewport = legacy_camera
        .as_ref()
        .map(LegacyCameraCapture::captured_viewport)
        .transpose()?;
    let view_camera = if let Some(capture) = legacy_camera.as_ref() {
        capture.preview_camera_frame()?
    } else {
        free_camera
            .map(|camera| camera.preview_frame(16.0 / 9.0))
            .ok_or_else(|| "static preview camera is unavailable".to_string())?
    };
    let camera = view_camera.vulkan_camera();
    let shadow_material_index = append_shadow_material(&mut materials)?;
    Ok(StaticPreviewScene {
        mesh,
        native_handedness_by_range,
        type16_present_ranges,
        materials,
        material_animations,
        ambient_effect_slots,
        control_point_light_slots,
        component_pose_buffers: component_pose_buffers_by_object,
        component_mount_poses: component_mount_poses_by_object,
        dynamic_component_geometry: dynamic_component_geometry_by_object,
        building_collision_bindings,
        control_animation_instances: control_animation_instances_by_object,
        dynamic_shadow_casters,
        sun_occlusion_range_indices,
        shadow_casters,
        shadow_receivers,
        shadow_material_index,
        terrain: Arc::new(terrain_query),
        camera,
        view_camera,
        captured_viewport,
        free_camera,
        camera_mode: if legacy_camera.is_some() {
            "legacy-d3d7-capture"
        } else {
            "free-flight"
        },
        mesh_components,
        terrain_components: 1,
    })
}

fn static_preview_terrain_base_materials(
    loader: &mut StandaloneWearMaterialLoader,
    root: &std::path::Path,
    land_msh_path: &str,
    mesh: &VulkanStaticMesh,
    materials: &mut Vec<VulkanStaticMaterial>,
    material_animations: &mut Vec<MaterialAnimationBinding>,
    static_material_phase: Option<u16>,
) -> Result<Vec<(u16, u16)>, String> {
    let land_path = root.join(land_msh_path);
    let land_parent = land_path
        .parent()
        .ok_or_else(|| format!("terrain mesh has no parent path: {}", land_path.display()))?;
    let land1_path = land_parent.join("Land1.wea");
    let land2_path = land_parent.join("Land2.wea");
    let mut packed_tags = mesh
        .draw_ranges
        .iter()
        .map(|range| range.material_index)
        .collect::<Vec<_>>();
    packed_tags.sort_unstable();
    packed_tags.dedup();
    packed_tags
        .into_iter()
        .map(|packed_tag| {
            let layers = TerrainMaterialLayers::from_packed_tag(packed_tag);
            let base_document = loader
                .material_document(&land1_path, layers.base_selection().material_index)
                .map_err(|err| format!("resolve terrain base MAT0 document: {err}"))?;
            let detail_document = loader
                .material_document(&land2_path, layers.detail_base_selection().material_index)
                .map_err(|err| format!("resolve terrain detail MAT0 document: {err}"))?;
            let overlay_selection = layers.overlay_selection();
            let overlay_detail_selection = layers.detail_overlay_selection();
            let overlay_document = overlay_selection
                .map(|selection| loader.material_document(&land1_path, selection.material_index))
                .transpose()
                .map_err(|err| format!("resolve terrain overlay MAT0 document: {err}"))?;
            let overlay_detail_document = overlay_detail_selection
                .map(|selection| loader.material_document(&land2_path, selection.material_index))
                .transpose()
                .map_err(|err| format!("resolve terrain overlay detail MAT0 document: {err}"))?;
            let base_phases = load_standalone_phase_set(
                loader,
                &land1_path,
                layers.base_selection().material_index,
                &base_document,
            )?;
            let detail_phases = load_standalone_phase_set(
                loader,
                &land2_path,
                layers.detail_base_selection().material_index,
                &detail_document,
            )?;
            let overlay_phases = overlay_selection
                .map(|selection| {
                    load_standalone_phase_set(
                        loader,
                        &land1_path,
                        selection.material_index,
                        overlay_document.as_ref().expect("overlay document"),
                    )
                })
                .transpose()?;
            let overlay_detail_phases = overlay_detail_selection
                .map(|selection| {
                    load_standalone_phase_set(
                        loader,
                        &land2_path,
                        selection.material_index,
                        overlay_detail_document
                            .as_ref()
                            .expect("overlay detail document"),
                    )
                })
                .transpose()?;
            let phase_count = base_phases.len();
            if phase_count == 0 || detail_phases.is_empty() {
                return Err(format!(
                    "terrain material tag 0x{packed_tag:04x} has incomplete phase tables"
                ));
            }
            if overlay_phases.as_ref().is_some_and(Vec::is_empty)
                || overlay_detail_phases.as_ref().is_some_and(Vec::is_empty)
            {
                return Err(format!(
                    "terrain material tag 0x{packed_tag:04x} has an empty optional phase table"
                ));
            }
            let initial_phase_index =
                usize::from(static_material_phase.unwrap_or(0)).min(phase_count.saturating_sub(1));
            let initial_detail_phase_index = usize::from(static_material_phase.unwrap_or(0))
                .min(detail_phases.len().saturating_sub(1));
            let initial_overlay_phase_index = overlay_phases.as_ref().map(|phases| {
                usize::from(static_material_phase.unwrap_or(0)).min(phases.len().saturating_sub(1))
            });
            let initial_overlay_detail_phase_index = overlay_detail_phases.as_ref().map(|phases| {
                usize::from(static_material_phase.unwrap_or(0)).min(phases.len().saturating_sub(1))
            });
            let mut phase_material_indices = Vec::with_capacity(phase_count);
            for phase_index in 0..phase_count {
                let (base, base_phase) = &base_phases[phase_index];
                // The base draw selector follows the base MAT0 timeline. The
                // other descriptor stages start at their own initial phase;
                // frame-time sampling below can then advance them separately.
                let (detail, detail_phase) = &detail_phases[initial_detail_phase_index];
                let overlay = overlay_phases
                    .as_ref()
                    .zip(initial_overlay_phase_index)
                    .map(|(phases, phase_index)| &phases[phase_index]);
                let overlay_detail = overlay_detail_phases
                    .as_ref()
                    .zip(initial_overlay_detail_phase_index)
                    .map(|(phases, phase_index)| &phases[phase_index]);
                let preview_selector = u16::try_from(materials.len()).map_err(|_| {
                    "static preview exceeds the available 16-bit material selector space"
                        .to_string()
                })?;
                materials.push(VulkanStaticMaterial {
                    material_index: preview_selector,
                    pipeline_category: base_phase.pipeline_category,
                    texture: base.clone(),
                    detail_texture: Some(detail.clone()),
                    overlay_texture: overlay.map(|(texture, _)| texture.clone()),
                    overlay_detail_texture: overlay_detail.map(|(texture, _)| texture.clone()),
                    diffuse_alpha: base_phase.diffuse_alpha,
                    overlay_diffuse_alpha: overlay.map(|(_, phase)| phase.diffuse_alpha),
                    directional_rgb: base_phase.directional_rgb,
                    additive_rgb: base_phase.additive_rgb,
                    uv_transform: base_phase.page_uv_transform,
                    overlay_directional_rgb: overlay.map(|(_, phase)| phase.directional_rgb),
                    overlay_additive_rgb: overlay.map(|(_, phase)| phase.additive_rgb),
                    specular_rgb: base_phase.specular_rgb,
                    specular_power: base_phase.power,
                    overlay_specular_rgb: overlay.map(|(_, phase)| phase.specular_rgb),
                    overlay_specular_power: overlay.map(|(_, phase)| phase.power),
                    detail_uv_transform: detail_phase.page_uv_transform,
                    overlay_uv_transform: overlay.map(|(_, phase)| phase.page_uv_transform),
                    overlay_detail_uv_transform: overlay_detail
                        .map(|(_, phase)| phase.page_uv_transform),
                    unlit: false,
                    sky_nebula_stars: false,
                    lightmap_mode: false,
                    sky_far_depth: false,
                    screen_tl: false,
                });
                phase_material_indices.push(usize::from(preview_selector));
            }
            let base_uvs = phase_uv_transforms_from_standalone(
                loader,
                &land1_path,
                layers.base_selection().material_index,
                &base_document,
            )?;
            let detail_uvs = phase_uv_transforms_from_standalone(
                loader,
                &land2_path,
                layers.detail_base_selection().material_index,
                &detail_document,
            )?;
            let overlay_uvs = match (&overlay_document, layers.overlay_selection()) {
                (Some(document), Some(selection)) => phase_uv_transforms_from_standalone(
                    loader,
                    &land1_path,
                    selection.material_index,
                    document,
                )?,
                _ => Vec::new(),
            };
            let overlay_detail_uvs =
                match (&overlay_detail_document, layers.detail_overlay_selection()) {
                    (Some(document), Some(selection)) => phase_uv_transforms_from_standalone(
                        loader,
                        &land2_path,
                        selection.material_index,
                        document,
                    )?,
                    _ => Vec::new(),
                };
            let stage_textures = MaterialStageTextures {
                detail: Some(
                    detail_phases
                        .iter()
                        .map(|(texture, _)| texture.clone())
                        .collect(),
                ),
                overlay: overlay_phases
                    .as_ref()
                    .map(|phases| phases.iter().map(|(texture, _)| texture.clone()).collect()),
                overlay_detail: overlay_detail_phases
                    .as_ref()
                    .map(|phases| phases.iter().map(|(texture, _)| texture.clone()).collect()),
                applied_material_phases: phase_material_indices
                    .iter()
                    .copied()
                    .map(|material_index| {
                        (
                            material_index,
                            [
                                initial_detail_phase_index,
                                initial_overlay_phase_index.unwrap_or(0),
                                initial_overlay_detail_phase_index.unwrap_or(0),
                            ],
                        )
                    })
                    .collect(),
            };
            material_animations.push(MaterialAnimationBinding {
                initial_phase_index: static_material_phase
                    .map_or(0, usize::from)
                    .min(base_document.phases.len().saturating_sub(1)),
                normalized_phase_override: None,
                ambient_fx_material_alpha: false,
                variants: vec![MaterialVariantSet {
                    phase_material_indices,
                    range_indices: Vec::new(),
                    pipeline_category: base_phases[initial_phase_index].1.pipeline_category,
                }],
                base: MaterialPhaseBinding {
                    document: base_document,
                    animation_block_index: 0,
                    wear_row_start_ms: 0,
                    random_state: packed_tag as u32,
                    frozen_phase_index: static_material_phase.map(usize::from),
                    phase_uv_transforms: base_uvs,
                },
                detail: Some(MaterialPhaseBinding {
                    document: detail_document,
                    animation_block_index: 0,
                    wear_row_start_ms: 0,
                    random_state: packed_tag as u32 ^ 0x5A5A_A5A5,
                    frozen_phase_index: static_material_phase.map(usize::from),
                    phase_uv_transforms: detail_uvs,
                }),
                overlay: overlay_document.map(|document| MaterialPhaseBinding {
                    document,
                    animation_block_index: 0,
                    wear_row_start_ms: 0,
                    random_state: packed_tag as u32 ^ 0xA5A5_5A5A,
                    frozen_phase_index: static_material_phase.map(usize::from),
                    phase_uv_transforms: overlay_uvs,
                }),
                overlay_detail: overlay_detail_document.map(|document| MaterialPhaseBinding {
                    document,
                    animation_block_index: 0,
                    wear_row_start_ms: 0,
                    random_state: packed_tag as u32 ^ 0xC3C3_3C3C,
                    frozen_phase_index: static_material_phase.map(usize::from),
                    phase_uv_transforms: overlay_detail_uvs,
                }),
                stage_textures: Some(stage_textures),
            });
            let preview_selector =
                u16::try_from(materials.len() - phase_count + initial_phase_index)
                    .map_err(|_| "terrain material selector exceeds u16".to_string())?;
            Ok((packed_tag, preview_selector))
        })
        .collect()
}

fn static_preview_component_materials(
    assets: &MissionAssets,
    visual: &PreparedVisual,
    mesh: &VulkanStaticMesh,
    static_material_phase: Option<u16>,
    materials: &mut Vec<VulkanStaticMaterial>,
    material_animations: &mut Vec<MaterialAnimationBinding>,
) -> Result<Vec<(u16, u16)>, String> {
    let mut source_selectors = mesh
        .draw_ranges
        .iter()
        .map(|range| range.material_index)
        .collect::<Vec<_>>();
    source_selectors.sort_unstable();
    source_selectors.dedup();
    source_selectors
        .into_iter()
        .map(|source_selector| {
            let material_id = visual
                .material_ids
                .get(usize::from(source_selector))
                .ok_or_else(|| {
                    format!(
                        "static preview MSH batch selector {source_selector} has no prepared WEAR material"
                    )
                })?;
            let material = assets.material_by_id(*material_id).ok_or_else(|| {
                format!("static preview prepared material {source_selector} is unavailable")
            })?;
            let initial_phase_index = usize::from(static_material_phase.unwrap_or(0))
                .min(material.mat0.phases.len().saturating_sub(1));
            if material.mat0.phases.is_empty() {
                return Err(format!(
                    "static preview material {source_selector} has no MAT0 phases"
                ));
            }
            let mut phase_material_indices = Vec::with_capacity(material.mat0.phases.len());
            for phase in &material.mat0.phases {
                let texture_name = phase_texture_name(phase);
                let prepared_texture = texture_name.as_ref().and_then(|name| {
                    assets.textures.iter().find(|texture| {
                        texture.usage == PreparedTextureUsage::Diffuse
                            && texture.source.name == *name
                    })
                });
                // Empty MAT0 texture names remain valid untextured materials.
                let texture = prepared_texture
                    .map(|texture| {
                        prepared_texture_to_vulkan(texture, "static preview diffuse texture")
                    })
                    .transpose()?
                    .unwrap_or_else(|| solid_environment_texture([255, 255, 255, 255]));
                let coefficients = phase.coefficients();
                let uv_transform = if let Some(texture) = prepared_texture {
                    page_uv_transform(
                        texture.texm.width(),
                        texture.texm.height(),
                        &texture.texm.page_rects(),
                        coefficients.page_index,
                    )?
                } else {
                    [0.0, 0.0, 1.0, 1.0]
                };
                let preview_selector = u16::try_from(materials.len()).map_err(|_| {
                    "static preview exceeds the available 16-bit material selector space"
                        .to_string()
                })?;
                materials.push(VulkanStaticMaterial {
                    material_index: preview_selector,
                    pipeline_category: material.pipeline_category,
                    texture,
                    detail_texture: None,
                    overlay_texture: None,
                    overlay_detail_texture: None,
                    diffuse_alpha: coefficients.opacity,
                    overlay_diffuse_alpha: None,
                    directional_rgb: coefficients.directional_rgb,
                    additive_rgb: coefficients.additive_rgb,
                    uv_transform,
                    overlay_directional_rgb: None,
                    overlay_additive_rgb: None,
                    specular_rgb: coefficients.specular_rgb,
                    specular_power: coefficients.power,
                    overlay_specular_rgb: None,
                    overlay_specular_power: None,
                    detail_uv_transform: [0.0, 0.0, 1.0, 1.0],
                    overlay_uv_transform: None,
                    overlay_detail_uv_transform: None,
                    unlit: false,
                    sky_nebula_stars: false,
                    lightmap_mode: false,
                    sky_far_depth: false,
                    screen_tl: false,
                });
                phase_material_indices.push(usize::from(preview_selector));
            }
            let preview_selector = u16::try_from(
                *phase_material_indices
                    .get(initial_phase_index)
                    .ok_or_else(|| "MAT0 phase variant table is empty".to_string())?,
            )
            .map_err(|_| "MAT0 phase variant selector exceeds u16".to_string())?;
            material_animations.push(MaterialAnimationBinding {
                initial_phase_index,
                normalized_phase_override: None,
                ambient_fx_material_alpha: false,
                variants: vec![MaterialVariantSet {
                    phase_material_indices,
                    range_indices: Vec::new(),
                    pipeline_category: material.pipeline_category,
                }],
                base: MaterialPhaseBinding {
                    document: material.mat0.clone(),
                    animation_block_index: 0,
                    wear_row_start_ms: 0,
                    random_state: material_id.raw() as u32,
                    frozen_phase_index: static_material_phase.map(usize::from),
                    phase_uv_transforms: phase_uv_transforms_from_assets(&material.mat0, assets),
                },
                detail: None,
                overlay: None,
                overlay_detail: None,
                stage_textures: None,
            });
            Ok((source_selector, preview_selector))
        })
        .collect()
}

fn prepared_texture_to_vulkan(
    texture: &PreparedTexture,
    label: &str,
) -> Result<VulkanStaticTexture, String> {
    let mip_images = (0..texture.texm.mip_count())
        .map(|level| texture.decode_mip_rgba8(u32::try_from(level).unwrap_or(u32::MAX)))
        .collect::<Result<Vec<_>, _>>()
        .map_err(|err| format!("decode {label} {:?}: {err}", texture.source.name))?;
    let image = mip_images
        .first()
        .ok_or_else(|| format!("{label} {:?} has no mip zero", texture.source.name))?;
    Ok(VulkanStaticTexture {
        width: image.width,
        height: image.height,
        rgba8: image.rgba8.clone(),
        mip_levels: mip_images
            .into_iter()
            .map(|image| VulkanStaticTextureMip {
                width: image.width,
                height: image.height,
                rgba8: image.rgba8,
            })
            .collect(),
    })
}

fn static_preview_lightmap_textures(
    assets: &MissionAssets,
    visual: &PreparedVisual,
) -> Result<Vec<VulkanStaticTexture>, String> {
    visual
        .lightmap_ids
        .iter()
        .map(|id| {
            let texture = assets
                .textures
                .iter()
                .find(|texture| {
                    texture.id == *id && texture.usage == PreparedTextureUsage::Lightmap
                })
                .ok_or_else(|| format!("static preview lightmap {id:?} is unavailable"))?;
            prepared_texture_to_vulkan(texture, "static preview lightmap")
        })
        .collect()
}

fn append_static_preview_component(
    target: &mut VulkanStaticMesh,
    component: VulkanStaticMesh,
    selector_remap: &[(u16, u16)],
    material_animations: Option<&mut Vec<MaterialAnimationBinding>>,
) -> Result<(), String> {
    append_static_preview_component_with_lightmaps(
        target,
        component,
        selector_remap,
        None,
        &[],
        material_animations,
    )
}

fn append_static_preview_component_with_lightmaps(
    target: &mut VulkanStaticMesh,
    component: VulkanStaticMesh,
    selector_remap: &[(u16, u16)],
    mut materials: Option<&mut Vec<VulkanStaticMaterial>>,
    lightmap_textures: &[VulkanStaticTexture],
    mut material_animations: Option<&mut Vec<MaterialAnimationBinding>>,
) -> Result<(), String> {
    let vertex_base = u32::try_from(target.vertices.len())
        .map_err(|_| "static preview vertex count exceeds u32".to_string())?;
    let first_index_base = u32::try_from(target.indices.len())
        .map_err(|_| "static preview index count exceeds u32".to_string())?;
    target
        .vertices
        .len()
        .checked_add(component.vertices.len())
        .ok_or_else(|| "static preview vertex count exceeds addressable memory".to_string())?;
    target.vertices.extend(component.vertices);
    target.indices.extend(
        component
            .indices
            .into_iter()
            .map(|index| {
                index
                    .checked_add(vertex_base)
                    .ok_or_else(|| "static preview vertex index exceeds u32".to_string())
            })
            .collect::<Result<Vec<_>, _>>()?,
    );
    // A lightmapped range must keep the lightmap material family when MAT0
    // advances to another phase.  The range's original selector identifies
    // the base binding, while the lightmap selector identifies the secondary
    // texture.  Keep the generated phase family and the binding/variant it
    // belongs to so update_material_animations can rebind every frame.
    let mut lightmap_materials: HashMap<(usize, u8), (Vec<usize>, usize, usize)> = HashMap::new();
    for range in component.draw_ranges {
        let source_material_index = selector_remap
            .iter()
            .find_map(|(source, preview)| (*source == range.material_index).then_some(*preview))
            .ok_or_else(|| {
                format!(
                    "static preview component has no material remap for selector {}",
                    range.material_index
                )
            })?;
        let (material_index, lightmap_variant) = if lightmap_textures
            .get(usize::from(range.lightmap_index))
            .is_some()
        {
            let key = (usize::from(source_material_index), range.lightmap_index);
            let (phase_material_indices, binding_index, variant_index) = if let Some(existing) =
                lightmap_materials.get(&key)
            {
                existing.clone()
            } else {
                let bindings = material_animations.as_deref().ok_or_else(|| {
                    "static preview lightmap animation storage is unavailable".to_string()
                })?;
                let (binding_index, source_phase_indices) =
                    find_material_animation_variant(bindings, usize::from(source_material_index))
                        .ok_or_else(|| {
                            format!(
                                "static preview material selector {source_material_index} has no MAT0 animation binding"
                            )
                        })?;
                let initial_phase_index = bindings[binding_index].initial_phase_index;
                let lightmap = lightmap_textures
                    .get(usize::from(range.lightmap_index))
                    .expect("lightmap presence checked above");
                let materials = materials.as_mut().ok_or_else(|| {
                    "static preview lightmap material storage is unavailable".to_string()
                })?;
                let mut phase_material_indices = Vec::with_capacity(source_phase_indices.len());
                for source_phase_index in source_phase_indices {
                    let mut lightmap_material = materials
                            .get(source_phase_index)
                            .cloned()
                            .ok_or_else(|| {
                                format!(
                                    "static preview material selector {source_phase_index} is unavailable"
                                )
                            })?;
                    let original_directional = lightmap_material.directional_rgb;
                    lightmap_material.directional_rgb = [0.0; 3];
                    lightmap_material.additive_rgb = original_directional;
                    lightmap_material.detail_texture = Some(lightmap.clone());
                    lightmap_material.detail_uv_transform = [0.0, 0.0, 1.0, 1.0];
                    lightmap_material.overlay_texture = None;
                    lightmap_material.overlay_detail_texture = None;
                    lightmap_material.overlay_diffuse_alpha = None;
                    lightmap_material.overlay_directional_rgb = None;
                    lightmap_material.overlay_additive_rgb = None;
                    lightmap_material.overlay_uv_transform = None;
                    lightmap_material.overlay_detail_uv_transform = None;
                    lightmap_material.unlit = false;
                    lightmap_material.sky_nebula_stars = false;
                    lightmap_material.lightmap_mode = true;
                    let index = u16::try_from(materials.len()).map_err(|_| {
                        "static preview exceeds the available 16-bit material selector space"
                            .to_string()
                    })?;
                    lightmap_material.material_index = index;
                    materials.push(lightmap_material);
                    phase_material_indices.push(usize::from(index));
                }
                let initial_selector = phase_material_indices
                    .get(initial_phase_index)
                    .copied()
                    .ok_or_else(|| "static preview lightmap phase table is empty".to_string())?;
                let pipeline_category = materials
                    .get(initial_selector)
                    .map(|material| material.pipeline_category)
                    .ok_or_else(|| {
                        "static preview lightmap material selector is unavailable".to_string()
                    })?;
                let bindings = material_animations.as_deref_mut().ok_or_else(|| {
                    "static preview lightmap animation storage is unavailable".to_string()
                })?;
                let variant_index = bindings[binding_index].variants.len();
                bindings[binding_index].variants.push(MaterialVariantSet {
                    phase_material_indices: phase_material_indices.clone(),
                    range_indices: Vec::new(),
                    pipeline_category,
                });
                let value = (phase_material_indices, binding_index, variant_index);
                lightmap_materials.insert(key, value.clone());
                value
            };
            let initial_material = *phase_material_indices
                .get(
                    material_animations
                        .as_deref()
                        .and_then(|bindings| bindings.get(binding_index))
                        .map_or(0, |binding| binding.initial_phase_index),
                )
                .ok_or_else(|| "static preview lightmap phase table is empty".to_string())?;
            (
                u16::try_from(initial_material).map_err(|_| {
                    "static preview lightmap material selector exceeds u16".to_string()
                })?,
                Some((binding_index, variant_index)),
            )
        } else {
            (source_material_index, None)
        };
        let target_range_index = target.draw_ranges.len();
        target
            .draw_ranges
            .push(fparkan_render_vulkan::VulkanStaticDrawRange {
                first_index: first_index_base
                    .checked_add(range.first_index)
                    .ok_or_else(|| "static preview index range exceeds u32".to_string())?,
                material_index,
                ..range
            });
        if let Some(bindings) = material_animations.as_deref_mut() {
            if let Some((binding_index, variant_index)) = lightmap_variant {
                bindings
                    .get_mut(binding_index)
                    .and_then(|binding| binding.variants.get_mut(variant_index))
                    .ok_or_else(|| {
                        "static preview lightmap animation variant is missing".to_string()
                    })?
                    .range_indices
                    .push(target_range_index);
            } else {
                register_material_range(
                    bindings,
                    usize::from(source_material_index),
                    target_range_index,
                );
            }
        }
    }
    Ok(())
}

fn load_standalone_vulkan_texture(
    loader: &mut StandaloneWearMaterialLoader,
    wear_path: &Path,
    material_index: u16,
    phase_index: u16,
) -> Result<(VulkanStaticTexture, PreparedMaterialPhase), String> {
    let (mips, phase) = loader.load(wear_path, material_index, phase_index)?;
    let first = mips
        .first()
        .ok_or_else(|| "standalone TEXM mip loader returned no mip zero".to_string())?;
    Ok((
        VulkanStaticTexture {
            width: first.width,
            height: first.height,
            rgba8: first.rgba8.clone(),
            mip_levels: mips
                .into_iter()
                .map(|image| VulkanStaticTextureMip {
                    width: image.width,
                    height: image.height,
                    rgba8: image.rgba8,
                })
                .collect(),
        },
        phase,
    ))
}

fn load_standalone_phase_set(
    loader: &mut StandaloneWearMaterialLoader,
    wear_path: &Path,
    material_index: u16,
    document: &Mat0Document,
) -> Result<Vec<(VulkanStaticTexture, PreparedMaterialPhase)>, String> {
    (0..document.phases.len())
        .map(|phase_index| {
            load_standalone_vulkan_texture(
                loader,
                wear_path,
                material_index,
                u16::try_from(phase_index)
                    .map_err(|_| "MAT0 phase index exceeds u16".to_string())?,
            )
        })
        .collect()
}

fn run_static_vulkan_mode(
    preview: StaticPreviewScene,
    environment: Option<DynamicEnvironment>,
    audio: Option<audio::GameAudio>,
    target_frames: u64,
    mission: &str,
    object_count: usize,
    readback_out: Option<&std::path::Path>,
    readback_sequence_out: Option<&std::path::Path>,
    enable_validation: bool,
    control_clock_target_ms: Option<u32>,
    startup_timings: StartupTimings,
) -> Result<String, String> {
    let event_loop = EventLoop::new().map_err(|err| format!("winit event loop: {err}"))?;
    event_loop.set_control_flow(ControlFlow::Poll);
    let mut preview = preview;
    let mut environment = environment;
    // Reserve the projected-shadow draw range before the environment builder
    // reorders its fixed passes. The range itself remains a stable draw slot;
    // frame geometry is appended after every static environment allocation.
    let mut shadow_range = append_environment_range(
        &mut preview.mesh,
        preview.shadow_material_index,
        shadow_placeholder_vertices(),
        quad_indices(1)?,
        projected_shadow_pipeline_state(),
    )?;
    let environment_gpu = match environment.as_mut() {
        Some(environment) => {
            let camera = preview.view_camera;
            let environment_materials = environment.materials.clone();
            let material_assets = environment.material_assets.clone();
            let sky_mesh = environment.sky.mesh().clone();
            Some(EnvironmentGpuScene::new(
                &mut preview.mesh,
                &mut preview.native_handedness_by_range,
                &mut preview.type16_present_ranges,
                &mut preview.materials,
                &mut preview.material_animations,
                &mut preview.ambient_effect_slots,
                &mut preview.dynamic_shadow_casters,
                &mut preview.sun_occlusion_range_indices,
                &environment_materials,
                &material_assets,
                &sky_mesh,
                &camera,
                &mut shadow_range.range_index,
            )?)
        }
        None => None,
    };
    let shadow_base_vertex = preview.mesh.vertices.len();
    let shadow_base_index = preview.mesh.indices.len();
    let mut app = StaticVulkanApp::new(
        preview,
        environment,
        environment_gpu,
        shadow_range,
        shadow_base_vertex,
        shadow_base_index,
        audio,
        target_frames,
        mission,
        object_count,
        readback_out.map(std::path::Path::to_path_buf),
        readback_sequence_out.map(std::path::Path::to_path_buf),
        enable_validation,
        control_clock_target_ms,
        startup_timings,
    );
    if let Err(err) = event_loop.run_app(&mut app) {
        app.error = Some(format!("winit event loop: {err}"));
    }
    app.finish()
}

struct StaticVulkanApp {
    mesh: VulkanStaticMesh,
    native_handedness_by_range: HashMap<usize, i8>,
    type16_present_ranges: HashSet<usize>,
    materials: Vec<VulkanStaticMaterial>,
    material_animations: Vec<MaterialAnimationBinding>,
    ambient_effect_slots: Vec<AmbientEffectGpuSlot>,
    control_point_light_slots: Vec<ControlPointLightSlot>,
    control_effect_random_states: HashMap<ControlEffectInstanceKey, ControlEffectRandomState>,
    component_pose_buffers: Vec<Vec<Option<NodePoseBuffer>>>,
    component_mount_poses: Vec<Vec<Option<VulkanNodePose>>>,
    dynamic_component_geometry: Vec<Vec<Option<DynamicComponentGeometry>>>,
    building_collision_bindings: Vec<BuildingCollisionBinding>,
    control_animation_instances: Vec<Vec<Option<ControlAnimationInstance>>>,
    dynamic_shadow_casters: Vec<DynamicShadowCaster>,
    sun_occlusion_range_indices: Vec<usize>,
    terrain: Arc<TerrainWorld>,
    world_range_indices: Vec<usize>,
    world_range_index_counts: HashMap<usize, u32>,
    camera: VulkanStaticCamera,
    view_camera: PreviewCameraFrame,
    captured_viewport: Option<CapturedViewport>,
    free_camera: Option<FreeFlightCamera>,
    environment: Option<DynamicEnvironment>,
    environment_gpu: Option<EnvironmentGpuScene>,
    shadow_range: EnvironmentGpuRange,
    shadow_base_vertex: usize,
    shadow_base_index: usize,
    shadow_material_index: usize,
    shadow_casters: Vec<ShadowCaster>,
    shadow_receivers: Vec<ShadowTriangle>,
    shadow_cache: ShadowPageCache,
    shadow_last_evidence: ShadowFrameEvidence,
    last_environment_control_clock_ms: u32,
    control_point_lights_diagnostic_reported: bool,
    simulation_last_tick: Instant,
    live_clock_paused_for_zero_extent: bool,
    simulation_elapsed: Duration,
    simulation_time_ms: u32,
    simulation_update_generation: u64,
    pending_scene_update: Option<SceneFrameUpdate>,
    environment_primitive_count: usize,
    pressed_keys: HashSet<KeyCode>,
    mouse_look: bool,
    audio: Option<audio::GameAudio>,
    camera_mode: &'static str,
    mesh_components: usize,
    terrain_components: usize,
    target_frames: u64,
    control_clock_target_ms: Option<u32>,
    mission: String,
    object_count: usize,
    readback_out: Option<PathBuf>,
    readback_sequence_out: Option<PathBuf>,
    enable_validation: bool,
    startup_timings: StartupTimings,
    window_id: Option<WindowId>,
    window: Option<Window>,
    renderer: Option<VulkanSmokeRenderer>,
    frames_presented: u64,
    output: Option<String>,
    error: Option<String>,
}

impl StaticVulkanApp {
    fn new(
        preview: StaticPreviewScene,
        environment: Option<DynamicEnvironment>,
        environment_gpu: Option<EnvironmentGpuScene>,
        shadow_range: EnvironmentGpuRange,
        shadow_base_vertex: usize,
        shadow_base_index: usize,
        audio: Option<audio::GameAudio>,
        target_frames: u64,
        mission: &str,
        object_count: usize,
        readback_out: Option<PathBuf>,
        readback_sequence_out: Option<PathBuf>,
        enable_validation: bool,
        control_clock_target_ms: Option<u32>,
        startup_timings: StartupTimings,
    ) -> Self {
        let mut fixed_range_indices = environment_gpu
            .as_ref()
            .map(EnvironmentGpuScene::fixed_range_indices)
            .unwrap_or_default();
        fixed_range_indices.extend(preview.ambient_effect_slots.iter().flat_map(|slot| {
            std::iter::once(slot.range.range_index).chain(
                slot.additional_particle_ranges
                    .iter()
                    .map(|range| range.range_index),
            )
        }));
        fixed_range_indices.insert(shadow_range.range_index);
        let world_range_indices =
            world_draw_range_indices(preview.mesh.draw_ranges.len(), &fixed_range_indices);
        let world_range_index_counts = preview
            .mesh
            .draw_ranges
            .iter()
            .enumerate()
            .filter(|(range_index, _)| !fixed_range_indices.contains(range_index))
            .map(|(range_index, range)| (range_index, range.index_count))
            .collect();
        Self {
            mesh: preview.mesh,
            native_handedness_by_range: preview.native_handedness_by_range,
            type16_present_ranges: preview.type16_present_ranges,
            materials: preview.materials,
            material_animations: preview.material_animations,
            ambient_effect_slots: preview.ambient_effect_slots,
            control_point_light_slots: preview.control_point_light_slots,
            control_effect_random_states: HashMap::new(),
            component_pose_buffers: preview.component_pose_buffers,
            component_mount_poses: preview.component_mount_poses,
            dynamic_component_geometry: preview.dynamic_component_geometry,
            building_collision_bindings: preview.building_collision_bindings,
            control_animation_instances: preview.control_animation_instances,
            dynamic_shadow_casters: preview.dynamic_shadow_casters,
            sun_occlusion_range_indices: preview.sun_occlusion_range_indices,
            terrain: preview.terrain,
            world_range_indices,
            world_range_index_counts,
            camera: preview.camera,
            view_camera: preview.view_camera,
            captured_viewport: preview.captured_viewport,
            free_camera: preview.free_camera,
            environment,
            environment_gpu,
            shadow_base_vertex,
            shadow_base_index,
            shadow_material_index: preview.shadow_material_index,
            shadow_range,
            shadow_casters: preview.shadow_casters,
            shadow_receivers: preview.shadow_receivers,
            shadow_cache: ShadowPageCache::default(),
            shadow_last_evidence: ShadowFrameEvidence::default(),
            last_environment_control_clock_ms: 0,
            control_point_lights_diagnostic_reported: false,
            simulation_last_tick: Instant::now(),
            live_clock_paused_for_zero_extent: false,
            simulation_elapsed: Duration::ZERO,
            simulation_time_ms: 0,
            simulation_update_generation: 0,
            pending_scene_update: None,
            environment_primitive_count: 0,
            pressed_keys: HashSet::new(),
            mouse_look: false,
            audio,
            camera_mode: preview.camera_mode,
            mesh_components: preview.mesh_components,
            terrain_components: preview.terrain_components,
            target_frames,
            control_clock_target_ms,
            mission: mission.to_string(),
            object_count,
            readback_out,
            readback_sequence_out,
            enable_validation,
            startup_timings,
            window_id: None,
            window: None,
            renderer: None,
            frames_presented: 0,
            output: None,
            error: None,
        }
    }

    fn configure_world_draw_ranges(
        &self,
        renderer: &mut VulkanSmokeRenderer,
    ) -> Result<(), String> {
        for &range_index in &self.world_range_indices {
            let range = self
                .mesh
                .draw_ranges
                .get(range_index)
                .ok_or_else(|| "world draw range index is out of bounds".to_string())?;
            let alpha = self
                .materials
                .get(usize::from(range.material_index))
                .map_or(1.0, |material| material.diffuse_alpha);
            let alpha_override = native_msh_diffuse_alpha_override(
                range.batch_flags,
                self.type16_present_ranges.contains(&range_index),
            );
            let effective_alpha = alpha_override.unwrap_or(alpha);
            renderer
                .set_draw_range_diffuse_alpha_override(range_index, alpha_override)
                .map_err(|error| {
                    format!("configure world draw range {range_index} alpha: {error}")
                })?;
            let transparent = native_world_transparent(range, effective_alpha);
            renderer
                .set_draw_range_transparency(range_index, transparent)
                .map_err(|error| format!("configure world draw range {range_index}: {error}"))?;
            let category = self
                .materials
                .get(usize::from(range.material_index))
                .ok_or_else(|| "world draw range has no material selector".to_string())?
                .pipeline_category;
            renderer
                .set_draw_range_material_category(range_index, category)
                .map_err(|error| {
                    format!("configure world material category {range_index}: {error}")
                })?;
            renderer
                .set_draw_range_index_count(
                    range_index,
                    world_draw_range_index_count(
                        &self.mesh,
                        range,
                        range.index_count,
                        effective_alpha,
                        self.view_camera.position,
                        self.native_handedness_by_range.get(&range_index).copied(),
                    ),
                )
                .map_err(|error| {
                    format!("configure world draw range {range_index} count: {error}")
                })?;
        }
        Ok(())
    }

    fn configure_ambient_effect_draw_ranges(
        &self,
        renderer: &mut VulkanSmokeRenderer,
    ) -> Result<(), String> {
        for slot in &self.ambient_effect_slots {
            for (effect_range, _) in ambient_effect_ranges(slot) {
                let range = self
                    .mesh
                    .draw_ranges
                    .get(effect_range.range_index)
                    .ok_or_else(|| "ambient FX draw range index is out of bounds".to_string())?;
                let category = self
                    .materials
                    .get(usize::from(range.material_index))
                    .ok_or_else(|| "ambient FX draw range has no MAT0 selector".to_string())?
                    .pipeline_category;
                renderer
                    .set_draw_range_transparency(effect_range.range_index, true)
                    .map_err(|error| {
                        format!(
                            "configure ambient FX draw range {}: {error}",
                            effect_range.range_index
                        )
                    })?;
                renderer
                    .set_draw_range_material_category(effect_range.range_index, category)
                    .map_err(|error| format!("configure ambient FX material category: {error}"))?;
            }
        }
        for (range_index, sort_key) in ambient_effect_draw_sort_keys(
            &self.mesh,
            &self.ambient_effect_slots,
            self.view_camera.position,
        )? {
            renderer
                .set_draw_range_sort_key(range_index, sort_key)
                .map_err(|error| {
                    format!("configure ambient FX draw range {range_index} sort key: {error}")
                })?;
        }
        Ok(())
    }

    fn update_world_transparency(
        mesh: &VulkanStaticMesh,
        materials: &[VulkanStaticMaterial],
        world_range_indices: &[usize],
        type16_present_ranges: &HashSet<usize>,
        world_range_index_counts: &HashMap<usize, u32>,
        native_handedness_by_range: &HashMap<usize, i8>,
        eye_world: [f32; 3],
        active_materials: &HashMap<usize, ActiveMaterialState>,
        renderer: &mut VulkanSmokeRenderer,
    ) -> Result<(), String> {
        for &range_index in world_range_indices {
            let range = mesh
                .draw_ranges
                .get(range_index)
                .ok_or_else(|| "world draw range index is out of bounds".to_string())?;
            let state = active_materials.get(&range_index);
            let material_alpha = state.map_or_else(
                || {
                    materials
                        .get(usize::from(range.material_index))
                        .map_or(1.0, |material| material.diffuse_alpha)
                },
                |state| state.diffuse_alpha,
            );
            let alpha_override = native_msh_diffuse_alpha_override(
                range.batch_flags,
                type16_present_ranges.contains(&range_index),
            );
            let alpha = alpha_override.unwrap_or(material_alpha);
            renderer
                .set_draw_range_diffuse_alpha_override(range_index, alpha_override)
                .map_err(|error| format!("update world draw range {range_index} alpha: {error}"))?;
            renderer
                .set_draw_range_transparency(range_index, native_world_transparent(range, alpha))
                .map_err(|error| format!("update world draw range {range_index}: {error}"))?;
            let original_index_count = *world_range_index_counts
                .get(&range_index)
                .ok_or_else(|| "world draw range count is missing".to_string())?;
            let count = world_draw_range_index_count(
                mesh,
                range,
                original_index_count,
                alpha,
                eye_world,
                native_handedness_by_range.get(&range_index).copied(),
            );
            renderer
                .set_draw_range_index_count(range_index, count)
                .map_err(|error| format!("update world draw range {range_index} count: {error}"))?;
        }
        Ok(())
    }

    fn world_draw_sort_keys(&self, camera_position: [f32; 3]) -> Result<Vec<(usize, f32)>, String> {
        let mut keys = Vec::with_capacity(self.world_range_indices.len());
        for &range_index in &self.world_range_indices {
            let sort_key = first_indexed_vertex_distance(&self.mesh, range_index, camera_position)?;
            keys.push((range_index, sort_key));
        }
        Ok(keys)
    }

    fn update_free_camera(&mut self, delta_seconds: f32, viewport: [f32; 2]) -> Result<(), String> {
        let Some(mut free_camera) = self.free_camera else {
            return Ok(());
        };
        let aspect = viewport[0] / viewport[1].max(1.0);
        let safe_position = free_camera.position;
        free_camera.advance(&self.pressed_keys, delta_seconds.clamp(0.0, 0.1));
        free_camera.keep_above_terrain(&self.terrain)?;
        if free_camera.position != safe_position
            && self.building_segment_blocked([safe_position, free_camera.position])?
        {
            free_camera.position = safe_position;
        }
        let view_camera = free_camera.preview_frame(aspect);
        let camera = view_camera.vulkan_camera();
        self.free_camera = Some(free_camera);
        self.view_camera = view_camera;
        self.camera = camera;
        Ok(())
    }

    fn building_segment_blocked(&self, world_segment: [[f32; 3]; 2]) -> Result<bool, String> {
        for binding in &self.building_collision_bindings {
            if binding.selected_nodes.is_empty() {
                continue;
            }
            let pose_buffer = self
                .component_pose_buffers
                .get(binding.object_index)
                .and_then(|components| components.get(binding.component_index))
                .and_then(Option::as_ref);
            let mount_pose = self
                .component_mount_poses
                .get(binding.object_index)
                .and_then(|components| components.get(binding.component_index))
                .copied()
                .flatten();
            let nodes = building_collision_nodes(binding, pose_buffer, mount_pose)?;
            if query_building_segment_world(&binding.model, &nodes, world_segment)
                .map_err(|error| {
                    format!(
                        "query building collision object {} component {} model {}: {error}",
                        binding.object_index, binding.component_index, binding.model_source
                    )
                })?
                .is_some()
            {
                return Ok(true);
            }
        }
        Ok(false)
    }

    fn sample_frame_clock(&mut self) -> FrameClockSample {
        if let Some(target_ms) = self.control_clock_target_ms {
            let time_ms =
                control_clock_ms_for_frame(target_ms, self.frames_presented, self.target_frames);
            self.simulation_elapsed = Duration::from_millis(u64::from(time_ms));
            self.simulation_time_ms = time_ms;
            return FrameClockSample {
                id: SceneSampleId::Replay(self.frames_presented),
                time_ms,
                delta_seconds: replay_environment_delta_seconds(
                    self.last_environment_control_clock_ms,
                    time_ms,
                ),
            };
        }
        self.sample_live_frame_clock_at(Instant::now())
    }

    fn pending_or_sample_frame_clock(&mut self) -> FrameClockSample {
        match self.pending_scene_update.as_ref() {
            Some(pending) => pending.clock,
            None => self.sample_frame_clock(),
        }
    }

    fn sample_live_frame_clock_at(&mut self, now: Instant) -> FrameClockSample {
        let elapsed = now.saturating_duration_since(self.simulation_last_tick);
        self.simulation_last_tick = now;
        self.simulation_elapsed = self.simulation_elapsed.saturating_add(elapsed);
        self.simulation_time_ms = self.simulation_elapsed.as_millis() as u32;
        let sample_id = SceneSampleId::Live(self.simulation_update_generation);
        self.simulation_update_generation = self.simulation_update_generation.saturating_add(1);
        FrameClockSample {
            id: sample_id,
            time_ms: self.simulation_time_ms,
            delta_seconds: elapsed.as_secs_f32(),
        }
    }

    fn pause_live_clock_at(&mut self, now: Instant) {
        self.live_clock_paused_for_zero_extent = true;
        self.simulation_last_tick = now;
    }

    fn resume_live_clock_at(&mut self, now: Instant) {
        if self.live_clock_paused_for_zero_extent {
            self.simulation_last_tick = now;
            self.live_clock_paused_for_zero_extent = false;
        }
    }

    fn update_shadow(
        mesh: &mut VulkanStaticMesh,
        shadow_cache: &mut ShadowPageCache,
        shadow_casters: &[ShadowCaster],
        shadow_receivers: &[ShadowTriangle],
        shadow_range: EnvironmentGpuRange,
        shadow_base_vertex: usize,
        shadow_base_index: usize,
        shadow_material_index: usize,
        uploaded_shadow_atlas: &mut VulkanStaticTexture,
        renderer: &mut VulkanSmokeRenderer,
        control_point_lights: &[(VulkanPointLight, u32)],
        sky_frame: Option<&SkyFrame<'_>>,
        environment_frame: Option<&EnvironmentFrame>,
        shadow_camera: Option<ShadowCamera>,
    ) -> Result<ShadowFrameEvidence, String> {
        let lights = shadow_lights(sky_frame, environment_frame, renderer, control_point_lights);
        let visible_casters = native_visible_shadow_casters(
            shadow_casters,
            renderer.frame_uniforms().clip_from_world,
        );
        let frame = shadow_cache
            .build(ShadowScene {
                lights: &lights,
                casters: &visible_casters,
                receivers: shadow_receivers,
                fade: 1.0,
                smooth_passes: 1,
                camera: shadow_camera,
                lod: ShadowLodSettings::default(),
            })
            .map_err(|error| format!("build projected shadow frame: {error}"))?;
        let geometry = append_shadow_frame_geometry(
            mesh,
            shadow_range,
            shadow_base_vertex,
            shadow_base_index,
            &frame,
        )?;
        let atlas = shadow_atlas_texture_from_frame(&frame);
        if atlas != *uploaded_shadow_atlas {
            renderer
                .update_material_texture(shadow_material_index, 0, &atlas)
                .map_err(|error| format!("upload projected shadow atlas: {error}"))?;
            *uploaded_shadow_atlas = atlas;
        }
        renderer
            .update_mesh_geometry(&mesh.vertices, &mesh.indices, &[geometry])
            .map_err(|error| format!("upload environment and shadow geometry: {error}"))?;
        Ok(ShadowFrameEvidence {
            visible_casters: visible_casters.len(),
            projected_indices: frame.indices.len(),
        })
    }

    fn prepare_scene_update(
        &mut self,
        clock: FrameClockSample,
        drawable_viewport: [f32; 2],
    ) -> Result<(), String> {
        let viewport = self.captured_viewport.map_or_else(
            || [drawable_viewport[0].max(1.0), drawable_viewport[1].max(1.0)],
            |viewport| [viewport.extent[0] as f32, viewport.extent[1] as f32],
        );
        let aspect = viewport[0] / viewport[1].max(1.0);
        if let Some((pending_id, pending_viewport)) = self
            .pending_scene_update
            .as_ref()
            .map(|pending| (pending.clock.id, pending.viewport))
        {
            if pending_id == clock.id {
                if pending_viewport != viewport {
                    self.refresh_pending_scene_viewport(viewport, aspect)?;
                }
                return Ok(());
            }
        }
        let control_clock_ms = clock.time_ms;
        let effect_elapsed_seconds = control_clock_ms as f32 / 1000.0;
        // CTLD's validated NDP defaults seed the native query gate. This
        // preview does not process mission Action1 updates, so it retains that
        // initial provider value for the capture.
        update_control_animation_pose_buffers(
            &mut self.control_animation_instances,
            &mut self.component_pose_buffers,
            control_clock_ms,
        )?;
        update_dynamic_component_geometry(
            &self.dynamic_component_geometry,
            &self.component_pose_buffers,
            &mut self.component_mount_poses,
            &mut self.mesh,
        )?;
        self.update_free_camera(clock.delta_seconds, viewport)?;
        refresh_dynamic_shadow_casters(
            &mut self.shadow_casters,
            &self.dynamic_shadow_casters,
            &self.mesh,
            &self.component_pose_buffers,
            &self.component_mount_poses,
        )?;
        for slot in &mut self.ambient_effect_slots {
            if slot.owner_component_is_mounted {
                slot.mount_pose = self
                    .component_mount_poses
                    .get(slot.owner_object_index)
                    .and_then(|components| components.get(slot.owner_component_index))
                    .copied()
                    .flatten();
            }
        }
        let control_effect_random_samples = advance_control_effect_random_states(
            &mut self.control_effect_random_states,
            &self.ambient_effect_slots,
            &self.control_point_light_slots,
            clock.id,
            control_clock_ms,
            effect_elapsed_seconds,
        );
        let control_point_lights = update_control_point_lights(
            &mut self.control_point_light_slots,
            &self.component_pose_buffers,
            &self.component_mount_poses,
            effect_elapsed_seconds,
            &control_effect_random_samples,
            std::env::var_os("FPARKAN_CONTROL_POINT_LIGHT_DIAGNOSTIC").is_some()
                && !self.control_point_lights_diagnostic_reported
                && self
                    .control_clock_target_ms
                    .is_none_or(|target_ms| control_clock_ms >= target_ms),
        );
        let control_vulkan_lights = ordinary_control_point_lights(&control_point_lights);
        let effect_updates = update_ambient_effect_geometry(
            &mut self.ambient_effect_slots,
            &self.component_pose_buffers,
            &mut self.mesh,
            &mut self.material_animations,
            effect_elapsed_seconds,
            &control_effect_random_samples,
            self.view_camera.position,
        )?;
        let world_sort_keys = self.world_draw_sort_keys(self.view_camera.position)?;
        let ambient_sort_keys = ambient_effect_draw_sort_keys(
            &self.mesh,
            &self.ambient_effect_slots,
            self.view_camera.position,
        )?;
        let camera = self.view_camera;
        let material_update = sample_material_animations(
            &mut self.material_animations,
            &self.materials,
            clock.time_ms,
        )?;
        let active_materials = &material_update.active_materials;
        apply_ambient_effect_material_tints(
            &self.ambient_effect_slots,
            &mut self.mesh,
            &effect_updates,
            &material_update.active_materials,
        )?;
        let diagnostic_mode = std::env::var("FPARKAN_AMBIENT_FX_DIAGNOSTIC").ok();
        if diagnostic_mode.is_some() {
            let generator_capture_is_final = diagnostic_mode.as_deref() == Some("generator")
                && self
                    .control_clock_target_ms
                    .is_none_or(|target_ms| control_clock_ms >= target_ms);
            for update in &effect_updates {
                let Some((slot, range)) = self.ambient_effect_slots.iter().find_map(|slot| {
                    ambient_effect_range_for(slot, update.range_index).map(|range| (slot, range))
                }) else {
                    continue;
                };
                if generator_capture_is_final
                    && slot.kind == AmbientEffectKind::GenerBall
                    && slot.control_source == "fortif.rlb/fr_l_gener.ctl"
                {
                    let random_sample = control_effect_random_samples
                        .get(&slot.random_instance_key)
                        .copied()
                        .unwrap_or_default();
                    let phase = ambient_effect_phase(
                        slot.time_mode,
                        slot.header_flags,
                        effect_elapsed_seconds,
                        slot.duration_seconds,
                    )
                    .map(|phase| {
                        native_command_phase(slot.header_flags, phase, random_sample.phase_jitter)
                    });
                    let evaluated = phase.and_then(|phase| {
                        evaluate_f_gener_ball(
                            &slot.command,
                            slot.command_index,
                            &slot.world_from_effect,
                            phase,
                            effect_elapsed_seconds,
                            self.view_camera.position,
                        )
                    });
                    let expected_vertices = evaluated.as_ref().map(|frame| frame.vertices);
                    let expected_center =
                        expected_vertices.map(|vertices| ambient_effect_quad_center(&vertices));
                    let expected_size =
                        expected_vertices.map(|vertices| ambient_effect_quad_size(&vertices));
                    let expected_screen = expected_vertices.and_then(|vertices| {
                        ambient_effect_projected_bounds(
                            &vertices,
                            self.view_camera.clip_from_world,
                            self.captured_viewport
                                .map_or([1280, 1024], |viewport| viewport.extent),
                        )
                    });
                    let actual_vertices = self
                        .mesh
                        .vertices
                        .get(range.vertex_start..range.vertex_start.saturating_add(4));
                    let actual_center: Option<[f32; 3]> = actual_vertices.map(|vertices| {
                        std::array::from_fn(|axis| {
                            vertices
                                .iter()
                                .map(|vertex| vertex.position[axis])
                                .sum::<f32>()
                                / 4.0
                        })
                    });
                    let actual_rgb = actual_vertices
                        .and_then(|vertices| vertices.first())
                        .map(|vertex| vertex.color);
                    let actual_alpha = actual_vertices
                        .and_then(|vertices| vertices.first())
                        .map(|vertex| vertex.overlay_alpha);
                    let material = active_materials.get(&update.range_index);
                    eprintln!(
                        "ambient_fx_generator_diagnostic elapsed={effect_elapsed_seconds:.3} clock_ms={control_clock_ms} owner_object={} owner_component={} source={} table={} row={} points={:?} opcode={:?} command={} range={} submitted_indices={} effect_phase={phase:?} evaluator_active={:?} fx_mat_phase={:?} fx_alpha={:?} expected_center={expected_center:?} expected_size={expected_size:?} expected_screen={expected_screen:?} actual_center={actual_center:?} actual_rgb={actual_rgb:?} actual_alpha={actual_alpha:?} mat_selector={:?} mat_phase_index={:?} sampled_mat_rgb={:?}",
                        slot.owner_object_index,
                        slot.owner_component_index,
                        slot.control_source,
                        slot.control_table_index,
                        slot.control_row_index,
                        slot.control_point_indices,
                        slot.command.opcode,
                        slot.command_index,
                        update.range_index,
                        update.index_count,
                        evaluated.as_ref().map(|frame| frame.active),
                        evaluated.as_ref().map(|frame| frame.material_phase),
                        evaluated.as_ref().map(|frame| frame.color[3]),
                        material.map(|material| material.material_index),
                        material.map(|material| material.phase_index),
                        material.map(|material| material.additive_rgb),
                    );
                    continue;
                }
                if diagnostic_mode.as_deref() == Some("generator")
                    || slot.control_source != "animals.rlb/a_a_l3.ctl"
                    || update.index_count == 0
                {
                    continue;
                }
                let start = range.vertex_start;
                let vertices = self
                    .mesh
                    .vertices
                    .get(start..start.saturating_add(range.vertex_capacity))
                    .unwrap_or_default();
                let center = if vertices.is_empty() {
                    [0.0; 3]
                } else {
                    std::array::from_fn(|axis| {
                        vertices
                            .iter()
                            .map(|vertex| vertex.position[axis])
                            .sum::<f32>()
                            / vertices.len() as f32
                    })
                };
                let color = vertices
                    .first()
                    .map(|vertex| vertex.color)
                    .unwrap_or([0.0; 3]);
                let alpha = vertices
                    .first()
                    .map(|vertex| vertex.overlay_alpha)
                    .unwrap_or(0.0);
                eprintln!(
                    "ambient_fx_diagnostic elapsed={effect_elapsed_seconds:.3} source={} table={} row={} points={:?} owners={:?} parent_translation={:?} opcode={:?} command={} range={} active_indices={} center={center:?} command_rgb={:?} sampled_mat_rgb={color:?} alpha={alpha:.3}",
                    slot.control_source,
                    slot.control_table_index,
                    slot.control_row_index,
                    slot.control_point_indices,
                    slot.control_point_owners,
                    [slot.world_from_effect[0][3], slot.world_from_effect[1][3], slot.world_from_effect[2][3]],
                    slot.command.opcode,
                    slot.command_index,
                    update.range_index,
                    update.index_count,
                    update.command_rgb,
                );
            }
        }

        if let Some(audio) = self.audio.as_mut() {
            audio
                .update_listener(camera.position, camera.forward, camera.up)
                .map_err(|error| format!("update audio listener: {error}"))?;
        }
        let environment = if let Some(environment) = self.environment.as_mut() {
            Some(environment.update_cpu(
                clock.delta_seconds,
                &camera,
                aspect,
                viewport,
                self.audio.as_mut(),
            )?)
        } else {
            None
        };
        self.environment_primitive_count = environment
            .as_ref()
            .map_or(0, |frame| frame.environment_frame.primitives.len());
        if matches!(clock.id, SceneSampleId::Replay(_)) {
            self.last_environment_control_clock_ms = control_clock_ms;
        }
        let environment_material_update =
            if let Some(environment_gpu) = self.environment_gpu.as_mut() {
                Some(sample_material_animations(
                    &mut environment_gpu.material_animations,
                    &self.materials,
                    clock.time_ms,
                )?)
            } else {
                None
            };
        let environment_point_light_count = environment.as_ref().map_or(0, |frame| {
            frame
                .environment_frame
                .point_lights
                .iter()
                .filter(|light| light.active)
                .count()
        });
        report_control_point_lights_once(
            &mut self.control_point_lights_diagnostic_reported,
            control_clock_ms,
            self.control_clock_target_ms,
            environment_point_light_count,
            &control_point_lights,
            &control_vulkan_lights,
        );
        self.pending_scene_update = Some(SceneFrameUpdate {
            clock,
            camera,
            viewport,
            aspect,
            control_point_lights,
            control_vulkan_lights,
            effect_updates,
            world_sort_keys,
            ambient_sort_keys,
            material_update,
            environment_material_update,
            environment,
        });
        Ok(())
    }

    fn refresh_pending_scene_viewport(
        &mut self,
        viewport: [f32; 2],
        aspect: f32,
    ) -> Result<(), String> {
        let Some((previous_camera, previous_aspect)) = self
            .pending_scene_update
            .as_ref()
            .map(|pending| (pending.camera, pending.aspect))
        else {
            return Ok(());
        };
        let camera = previous_camera.with_aspect(previous_aspect, aspect);
        self.view_camera = camera;
        self.camera = camera.vulkan_camera();
        let environment_camera = environment_camera_for_preview(&camera, aspect, viewport);
        if let Some(environment) = self
            .pending_scene_update
            .as_mut()
            .and_then(|pending| pending.environment.as_mut())
        {
            environment
                .environment_frame
                .reproject_for_camera(environment_camera);
        }
        let pending = self
            .pending_scene_update
            .as_mut()
            .expect("pending scene update was checked above");
        pending.camera = camera;
        pending.viewport = viewport;
        pending.aspect = aspect;
        Ok(())
    }

    fn render_scene_update(&mut self) -> Result<(), String> {
        let Some(frame) = self.pending_scene_update.as_ref() else {
            return Ok(());
        };
        let Some(renderer) = self.renderer.as_mut() else {
            return Ok(());
        };
        renderer
            .set_camera(frame.camera.vulkan_camera())
            .map_err(|error| format!("apply sampled scene camera: {error}"))?;
        apply_material_frame_update(
            &frame.material_update,
            &mut self.material_animations,
            renderer,
        )?;
        for update in &frame.effect_updates {
            renderer
                .set_draw_range_index_count(update.range_index, update.index_count)
                .map_err(|error| {
                    format!(
                        "update ambient FX draw range {}: {error}",
                        update.range_index
                    )
                })?;
        }
        for &(range_index, sort_key) in &frame.world_sort_keys {
            renderer
                .set_draw_range_sort_key(range_index, sort_key)
                .map_err(|error| {
                    format!("update dynamic world draw range {range_index} sort key: {error}")
                })?;
        }
        for &(range_index, sort_key) in &frame.ambient_sort_keys {
            renderer
                .set_draw_range_sort_key(range_index, sort_key)
                .map_err(|error| {
                    format!("update ambient FX draw range {range_index} sort key: {error}")
                })?;
        }
        Self::update_world_transparency(
            &self.mesh,
            &self.materials,
            &self.world_range_indices,
            &self.type16_present_ranges,
            &self.world_range_index_counts,
            &self.native_handedness_by_range,
            frame.camera.position,
            &frame.material_update.active_materials,
            renderer,
        )?;
        let shadow_camera = ShadowCamera {
            position: frame.camera.position,
            viewport_width: frame.viewport[0],
            horizontal_fov: horizontal_fov(&frame.camera, frame.aspect),
        };
        if let Some(sampled_environment) = frame.environment.as_ref() {
            let environment = self
                .environment
                .as_ref()
                .ok_or_else(|| "sampled atmosphere lost its owner".to_string())?;
            let sky_frame = SkyFrame::from_atmosphere(
                &sampled_environment.atmosphere,
                &environment.materials,
                sampled_environment.absolute_time_seconds,
            );
            let environment_frame = &sampled_environment.environment_frame;
            let mut uniforms = renderer.frame_uniforms();
            uniforms.clip_from_world = frame.camera.clip_from_world;
            for (target, source) in uniforms
                .directional_lights
                .iter_mut()
                .zip(sky_frame.directional_lights)
            {
                target.direction = source.direction;
                target.rgb = source.color;
                target.coefficients = [0.0, 0.0, 1.0];
                target.active = source.active;
            }
            uniforms.lighting_floor = sky_frame.lighting_floor;
            let fog_rgb = sky_frame
                .screen_gradient(frame.camera.native_sky_heading(), [0.0; 3])
                .color
                .rgba();
            uniforms.fog_color = [fog_rgb[0], fog_rgb[1], fog_rgb[2]];
            uniforms.fog_start = sky_frame.fog.start.max(0.0);
            uniforms.fog_end = sky_frame.fog.end.max(uniforms.fog_start);
            uniforms.camera_position = frame.camera.position;
            renderer
                .set_frame_uniforms(uniforms)
                .map_err(|error| format!("update sky frame uniforms: {error}"))?;
            let mut uniforms = renderer.frame_uniforms();
            uniforms.point_light = environment_frame
                .point_lights
                .iter()
                .find(|light| light.active)
                .map(|light| VulkanPointLight {
                    position: light.position,
                    rgb: [light.color[0], light.color[1], light.color[2]],
                    range: light.range,
                    coefficients: light.attenuation,
                    active: true,
                })
                .unwrap_or_default();
            renderer
                .set_frame_uniforms(uniforms)
                .map_err(|error| format!("update environment point-light uniforms: {error}"))?;
            let mut point_lights = environment_frame
                .point_lights
                .iter()
                .filter(|light| light.active)
                .map(|light| VulkanPointLight {
                    position: light.position,
                    rgb: [light.color[0], light.color[1], light.color[2]],
                    range: light.range,
                    coefficients: light.attenuation,
                    active: true,
                })
                .collect::<Vec<_>>();
            point_lights.extend(frame.control_vulkan_lights.iter().copied());
            renderer
                .set_point_lights(&point_lights)
                .map_err(|error| format!("update complete scene point-light set: {error}"))?;
            if let Some(environment_gpu) = self.environment_gpu.as_mut() {
                let material_update = frame
                    .environment_material_update
                    .as_ref()
                    .ok_or_else(|| "sampled environment material state is missing".to_string())?;
                apply_material_frame_update(
                    material_update,
                    &mut environment_gpu.material_animations,
                    renderer,
                )?;
                environment_gpu.update(
                    &mut self.mesh,
                    renderer,
                    material_update,
                    &sky_frame,
                    &sampled_environment.sky_mesh,
                    environment_frame,
                    &frame.camera,
                    frame.viewport,
                    &self.terrain,
                    &self.sun_occlusion_range_indices,
                )?;
            }
            let shadow_material = self
                .materials
                .get_mut(self.shadow_material_index)
                .ok_or_else(|| "projected shadow material is out of bounds".to_string())?;
            self.shadow_last_evidence = Self::update_shadow(
                &mut self.mesh,
                &mut self.shadow_cache,
                &self.shadow_casters,
                &self.shadow_receivers,
                self.shadow_range,
                self.shadow_base_vertex,
                self.shadow_base_index,
                self.shadow_material_index,
                &mut shadow_material.texture,
                renderer,
                &frame.control_point_lights,
                Some(&sky_frame),
                Some(environment_frame),
                Some(shadow_camera),
            )?;
        } else {
            renderer
                .set_point_lights(&frame.control_vulkan_lights)
                .map_err(|error| format!("update complete scene point-light set: {error}"))?;
            let shadow_material = self
                .materials
                .get_mut(self.shadow_material_index)
                .ok_or_else(|| "projected shadow material is out of bounds".to_string())?;
            self.shadow_last_evidence = Self::update_shadow(
                &mut self.mesh,
                &mut self.shadow_cache,
                &self.shadow_casters,
                &self.shadow_receivers,
                self.shadow_range,
                self.shadow_base_vertex,
                self.shadow_base_index,
                self.shadow_material_index,
                &mut shadow_material.texture,
                renderer,
                &frame.control_point_lights,
                None,
                None,
                Some(shadow_camera),
            )?;
        }
        Ok(())
    }

    fn record_presented_scene_frame(&mut self) -> u64 {
        let frame_index = self.frames_presented;
        self.frames_presented = self.frames_presented.saturating_add(1);
        self.pending_scene_update = None;
        frame_index
    }

    fn set_mouse_look(&mut self, active: bool) {
        self.mouse_look = active;
        if let Some(window) = self.window.as_ref() {
            if active {
                // Relative device motion keeps the camera usable at the edge
                // of the window. Locked grab is unavailable on a few window
                // backends, so confined grab is a safe fallback.
                if window.set_cursor_grab(CursorGrabMode::Locked).is_err() {
                    let _ = window.set_cursor_grab(CursorGrabMode::Confined);
                }
            } else {
                let _ = window.set_cursor_grab(CursorGrabMode::None);
            }
            window.set_cursor_visible(!active);
        }
    }

    fn schedule_next_redraw(&self) {
        if let Some(window) = self.window.as_ref() {
            window.request_redraw();
        }
    }

    fn complete(&mut self, event_loop: &ActiveEventLoop) {
        if let Some(audio) = self.audio.as_mut() {
            audio.shutdown();
        }
        let Some(renderer) = self.renderer.take() else {
            self.error = Some("native Vulkan renderer was not initialized".to_string());
            event_loop.exit();
            return;
        };
        let report = match renderer.shutdown() {
            Ok(report) => report,
            Err(err) => {
                self.error = Some(err.to_string());
                event_loop.exit();
                return;
            }
        };
        self.window.take();
        if self.enable_validation
            && (report.validation.warning_count != 0 || report.validation.error_count != 0)
        {
            self.error = Some(format!(
                "native Vulkan validation must stay clean (warnings={}, errors={}, vuids={:?})",
                report.validation.warning_count,
                report.validation.error_count,
                report.validation.vuids,
            ));
            event_loop.exit();
            return;
        }
        let validation_status = if self.enable_validation {
            "clean"
        } else {
            "disabled"
        };
        let readback_path = match (&self.readback_out, &report.readback_artifact) {
            (Some(path), Some(artifact)) => {
                if let Some(parent) = path.parent() {
                    if let Err(err) = std::fs::create_dir_all(parent) {
                        self.error = Some(format!("{}: {err}", parent.display()));
                        event_loop.exit();
                        return;
                    }
                }
                if let Err(err) = std::fs::write(path, &artifact.bytes) {
                    self.error = Some(format!("{}: {err}", path.display()));
                    event_loop.exit();
                    return;
                }
                Some(path.display().to_string())
            }
            (Some(_), None) => {
                self.error =
                    Some("native Vulkan renderer produced no synchronized readback".to_string());
                event_loop.exit();
                return;
            }
            (None, _) => None,
        };
        let readback_format = report
            .readback_artifact
            .as_ref()
            .map_or(report.renderer_report.swapchain_image_format, |artifact| {
                artifact.format
            });
        if let Some(control_clock_ms) = self.control_clock_target_ms {
            emit_control_animation_capture_diagnostics(
                &self.control_animation_instances,
                &self.component_pose_buffers,
                control_clock_ms,
            );
        }
        let captured_crop = self.captured_viewport.map_or_else(
            || "none".to_string(),
            |viewport| {
                format!(
                    "{:?} ({}x{})",
                    viewport.rect, viewport.extent[0], viewport.extent[1]
                )
            },
        );
        self.output = Some(format!(
            "rendered mission {}: {} frames, {} objects, {} mesh components, {} terrain components, camera={}, captured_viewport_crop={}, control_clock_ms={}, control_clock_mode={}, materials={}, environment_primitives={}, shadow_casters={}, shadow_indices={}, swapchain_recreates={}, validation={}, swapchain_format={}, readback_format={}, readback={}, readback_sequence={}, startup_ms={{mission_assets:{:.1},terrain_materials:{:.1},sky:{:.1},gpu_initialization:{:.1}}}",
            self.mission,
            self.frames_presented,
            self.object_count,
            self.mesh_components,
            self.terrain_components,
            self.camera_mode,
            captured_crop,
            self.control_clock_target_ms
                .map_or_else(|| "realtime".to_string(), |clock| clock.to_string()),
            control_clock_mode_label(self.control_clock_target_ms),
            self.materials.len(),
            self.environment_primitive_count,
            self.shadow_last_evidence.visible_casters,
            self.shadow_last_evidence.projected_indices,
            report.swapchain_recreate_count,
            validation_status,
            report.renderer_report.swapchain_image_format,
            readback_format,
            readback_path.as_deref().unwrap_or("none"),
            self.readback_sequence_out
                .as_deref()
                .map_or_else(|| "none".to_string(), |path| path.display().to_string()),
            elapsed_ms(self.startup_timings.mission_assets),
            elapsed_ms(self.startup_timings.terrain_materials),
            elapsed_ms(self.startup_timings.sky),
            elapsed_ms(self.startup_timings.gpu_initialization),
        ));
        event_loop.exit();
    }

    fn finish(self) -> Result<String, String> {
        self.output.ok_or_else(|| {
            self.error.unwrap_or_else(|| {
                "native Vulkan mode exited before producing a report".to_string()
            })
        })
    }
}

impl ApplicationHandler for StaticVulkanApp {
    fn device_event(
        &mut self,
        _event_loop: &ActiveEventLoop,
        _device_id: DeviceId,
        event: DeviceEvent,
    ) {
        if self.mouse_look {
            if let DeviceEvent::MouseMotion { delta } = event {
                if let Some(camera) = self.free_camera.as_mut() {
                    camera.look_delta(delta.0, delta.1);
                }
            }
        }
    }

    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
        if self.window.is_some() {
            return;
        }
        let plan = match WinitWindowPlan::smoke().validate() {
            Ok(plan) => plan,
            Err(err) => {
                self.error = Some(err.to_string());
                event_loop.exit();
                return;
            }
        };
        let (width, height) = self
            .captured_viewport
            .map(|viewport| (viewport.extent[0], viewport.extent[1]))
            .unwrap_or((plan.width, plan.height));
        let attributes = Window::default_attributes()
            .with_title("FParkan mission")
            .with_inner_size(WinitPhysicalSize::new(width, height))
            // The captured clip matrix is exact for the recorded viewport
            // aspect. Keep that drawable fixed; compare it with the same
            // (left, top, right, bottom) crop in the original capture.
            .with_resizable(self.captured_viewport.is_none());
        let window = match event_loop.create_window(attributes) {
            Ok(window) => window,
            Err(err) => {
                self.error = Some(format!("winit window: {err}"));
                event_loop.exit();
                return;
            }
        };
        let size = window.inner_size();
        if let Some(captured_viewport) = self.captured_viewport {
            if let Err(error) =
                validate_captured_drawable_extent(captured_viewport, [size.width, size.height])
            {
                self.error = Some(error);
                event_loop.exit();
                return;
            }
        }
        let Some(native_handles) = window_native_handles(&window) else {
            self.error = Some("winit window does not expose native handles".to_string());
            event_loop.exit();
            return;
        };
        let gpu_initialization_started = Instant::now();
        if let Err(error) = configure_world_material_categories(
            &mut self.mesh,
            &self.materials,
            &self.world_range_indices,
        ) {
            self.error = Some(error);
            event_loop.exit();
            return;
        }
        let mut renderer = match VulkanSmokeRenderer::new(&VulkanSmokeRendererCreateInfo {
            application_name: "fparkan-game".to_string(),
            native_handles,
            drawable_extent: (size.width.max(1), size.height.max(1)),
            render_request: WinitWindow::default_render_request(),
            enable_validation: self.enable_validation,
            mesh: self.mesh.clone(),
            camera: self.camera,
            materials: self.materials.clone(),
            bootstrap_progress: None,
        }) {
            Ok(renderer) => renderer,
            Err(error) => {
                self.error = Some(error.to_string());
                event_loop.exit();
                return;
            }
        };
        let background_ranges = self.environment_gpu.as_ref().map_or_else(
            Vec::new,
            EnvironmentGpuScene::transparent_background_range_indices,
        );
        if let Err(error) = renderer.set_world_transparent_background_ranges(&background_ranges) {
            self.error = Some(format!("configure world background ranges: {error}"));
            event_loop.exit();
            return;
        }
        if let Err(error) = self.configure_world_draw_ranges(&mut renderer) {
            self.error = Some(error);
            event_loop.exit();
            return;
        }
        if let Err(error) = self.configure_ambient_effect_draw_ranges(&mut renderer) {
            self.error = Some(error);
            event_loop.exit();
            return;
        }
        match self.world_draw_sort_keys(self.view_camera.position) {
            Ok(sort_keys) => {
                for (range_index, sort_key) in sort_keys {
                    if let Err(error) = renderer.set_draw_range_sort_key(range_index, sort_key) {
                        self.error = Some(format!(
                            "update world draw range {range_index} sort key: {error}"
                        ));
                        event_loop.exit();
                        return;
                    }
                }
            }
            Err(error) => {
                self.error = Some(error);
                event_loop.exit();
                return;
            }
        }
        self.startup_timings.gpu_initialization = gpu_initialization_started.elapsed();
        renderer.set_readback_enabled(
            self.readback_out.is_some() || self.readback_sequence_out.is_some(),
        );
        self.window_id = Some(window.id());
        self.window = Some(window);
        self.renderer = Some(renderer);
        self.simulation_last_tick = Instant::now();
        self.live_clock_paused_for_zero_extent = false;
        self.pending_scene_update = None;
        let drawable_size = self
            .window
            .as_ref()
            .map(Window::inner_size)
            .unwrap_or_default();
        if let Err(error) = self.update_free_camera(
            0.0,
            [drawable_size.width as f32, drawable_size.height as f32],
        ) {
            self.error = Some(error);
            event_loop.exit();
            return;
        }
        self.schedule_next_redraw();
    }

    fn window_event(
        &mut self,
        event_loop: &ActiveEventLoop,
        window_id: WindowId,
        event: WindowEvent,
    ) {
        if Some(window_id) != self.window_id {
            return;
        }
        match event {
            WindowEvent::CloseRequested => {
                self.complete(event_loop);
            }
            WindowEvent::Focused(focused) => {
                if !focused {
                    self.pressed_keys.clear();
                    self.set_mouse_look(false);
                }
                if let Some(audio) = self.audio.as_mut() {
                    audio.on_focus_changed(focused);
                }
            }
            WindowEvent::KeyboardInput { event, .. } => {
                if let PhysicalKey::Code(code) = event.physical_key {
                    if code == KeyCode::Escape && event.state == ElementState::Pressed {
                        if self.mouse_look {
                            self.set_mouse_look(false);
                        } else {
                            self.complete(event_loop);
                        }
                    } else if event.state == ElementState::Pressed {
                        self.pressed_keys.insert(code);
                    } else {
                        self.pressed_keys.remove(&code);
                    }
                }
            }
            WindowEvent::MouseInput { state, button, .. } => {
                if button == MouseButton::Right {
                    self.set_mouse_look(state == ElementState::Pressed);
                }
            }
            WindowEvent::CursorMoved { .. } => {}
            WindowEvent::Resized(size) => {
                // Queued creation resize events can predate the current physical drawable.
                let drawable_size = if self.captured_viewport.is_some() {
                    self.window.as_ref().map(Window::inner_size).unwrap_or(size)
                } else {
                    size
                };
                if let Some(captured_viewport) = self.captured_viewport {
                    if drawable_size.width != 0 && drawable_size.height != 0 {
                        if let Err(error) = validate_captured_drawable_extent(
                            captured_viewport,
                            [drawable_size.width, drawable_size.height],
                        ) {
                            self.error = Some(error);
                            event_loop.exit();
                            return;
                        }
                    }
                }
                if let Some(renderer) = self.renderer.as_mut() {
                    renderer.request_resize((drawable_size.width, drawable_size.height));
                }
                if drawable_size.width == 0 || drawable_size.height == 0 {
                    event_loop.set_control_flow(ControlFlow::Wait);
                    self.pause_live_clock_at(Instant::now());
                } else {
                    event_loop.set_control_flow(ControlFlow::Poll);
                    self.resume_live_clock_at(Instant::now());
                    // The pending simulation sample is reused; its view and
                    // viewport-dependent geometry refresh before the retry.
                }
            }
            WindowEvent::RedrawRequested => {
                if self.pending_scene_update.is_none() {
                    return;
                }
                if let Err(error) = self.render_scene_update() {
                    self.error = Some(error);
                    event_loop.exit();
                    return;
                }
                let diagnostic_clock_ms = self
                    .pending_scene_update
                    .as_ref()
                    .map_or(self.simulation_time_ms, |frame| frame.clock.time_ms);
                let outcome = {
                    let Some(renderer) = self.renderer.as_mut() else {
                        self.error = Some("native Vulkan renderer was not initialized".to_string());
                        event_loop.exit();
                        return;
                    };
                    renderer.draw_frame()
                };
                match outcome {
                    Ok(VulkanSmokeFrameOutcome::Presented) => {
                        let frame_index = self.record_presented_scene_frame();
                        if let Some(directory) = self.readback_sequence_out.as_deref() {
                            let artifact = match self
                                .renderer
                                .as_mut()
                                .expect("renderer presented a frame")
                                .readback_last_submitted_frame()
                            {
                                Ok(Some(artifact)) => artifact,
                                Ok(None) => {
                                    self.error = Some(
                                        "native Vulkan renderer produced no synchronized sequence readback"
                                            .to_string(),
                                    );
                                    event_loop.exit();
                                    return;
                                }
                                Err(error) => {
                                    self.error =
                                        Some(format!("read back frame {frame_index}: {error}"));
                                    event_loop.exit();
                                    return;
                                }
                            };
                            if let Err(error) = write_readback_sequence_frame(
                                directory,
                                frame_index,
                                diagnostic_clock_ms,
                                &artifact,
                            ) {
                                self.error = Some(error);
                                event_loop.exit();
                                return;
                            }
                        }
                    }
                    Ok(VulkanSmokeFrameOutcome::Recreated) => {}
                    Ok(VulkanSmokeFrameOutcome::ZeroExtent) => {
                        if self.window.as_ref().is_some_and(|window| {
                            let size = window.inner_size();
                            size.width == 0 || size.height == 0
                        }) {
                            event_loop.set_control_flow(ControlFlow::Wait);
                            self.pause_live_clock_at(Instant::now());
                        }
                    }
                    Err(err) => {
                        self.error = Some(err.to_string());
                        event_loop.exit();
                        return;
                    }
                }
                if self.target_frames != 0 && self.frames_presented >= self.target_frames {
                    self.complete(event_loop);
                }
            }
            _ => {}
        }
    }

    fn about_to_wait(&mut self, event_loop: &ActiveEventLoop) {
        if self.output.is_some() || self.error.is_some() {
            return;
        }
        let Some(window) = self.window.as_ref() else {
            return;
        };
        let size = window.inner_size();
        if size.width == 0 || size.height == 0 {
            // Wait for a resize instead of spinning simulation updates while
            // the window has no drawable surface.
            event_loop.set_control_flow(ControlFlow::Wait);
            self.pause_live_clock_at(Instant::now());
            return;
        }
        event_loop.set_control_flow(ControlFlow::Poll);
        self.resume_live_clock_at(Instant::now());
        let clock = self.pending_or_sample_frame_clock();
        if let Err(error) =
            self.prepare_scene_update(clock, [size.width as f32, size.height as f32])
        {
            self.error = Some(error);
            event_loop.exit();
            return;
        }
        self.schedule_next_redraw();
    }
}

#[derive(Clone, Debug, PartialEq)]
struct Args {
    root: PathBuf,
    mission: String,
    frames: u64,
    atmosphere_seconds: Option<f32>,
    control_clock_ms: Option<u32>,
    validation: bool,
    readback_out: Option<PathBuf>,
    readback_sequence_out: Option<PathBuf>,
    preview_roots: NonZeroUsize,
    legacy_camera_capture: Option<PathBuf>,
    static_animation_frame: Option<u16>,
    static_material_phase: Option<u16>,
}

impl Args {
    fn parse(args: &[String]) -> Result<Self, String> {
        let mut root = None;
        let mut mission = None;
        // Zero means keep the interactive preview open until the user closes
        // it. A bounded `--frames N` remains available for smoke/readback
        // runs and validation scripts.
        let mut frames = 0;
        let mut atmosphere_seconds = None;
        let mut control_clock_ms = None;
        let mut validation = false;
        let mut readback_out = None;
        let mut readback_sequence_out = None;
        // A native static-Vulkan invocation is the usable mission preview, so
        // its default scope covers every root. `PreviewRoots` is clamped by the
        // runtime to the decoded mission length; an explicit --preview-roots N
        // remains available for bounded diagnostic work.
        let mut preview_roots = NonZeroUsize::MAX;
        let mut legacy_camera_capture = None;
        let mut static_animation_frame = None;
        let mut static_material_phase = None;
        let mut iter = args.iter();
        while let Some(arg) = iter.next() {
            match arg.as_str() {
                "--root" => {
                    root = Some(
                        iter.next()
                            .map(PathBuf::from)
                            .ok_or_else(|| "--root requires a path".to_string())?,
                    );
                }
                "--mission" => {
                    mission = Some(
                        iter.next()
                            .cloned()
                            .ok_or_else(|| "--mission requires a path".to_string())?,
                    );
                }
                "--frames" => {
                    frames = iter
                        .next()
                        .ok_or_else(|| "--frames requires a value".to_string())?
                        .parse()
                        .map_err(|_| "--frames must be an integer".to_string())?;
                }
                "--atmosphere-seconds" => {
                    let value = iter
                        .next()
                        .ok_or_else(|| "--atmosphere-seconds requires a value".to_string())?
                        .parse::<f32>()
                        .map_err(|_| "--atmosphere-seconds must be a number".to_string())?;
                    if !value.is_finite() || value < 0.0 {
                        return Err(
                            "--atmosphere-seconds must be finite and non-negative".to_string()
                        );
                    }
                    atmosphere_seconds = Some(value);
                }
                "--control-clock-ms" => {
                    control_clock_ms = Some(
                        iter.next()
                            .ok_or_else(|| "--control-clock-ms requires a value".to_string())?
                            .parse()
                            .map_err(|_| "--control-clock-ms must be a u32 integer".to_string())?,
                    );
                }
                "--validation" => {
                    validation = true;
                }
                "--readback-out" => {
                    readback_out = Some(
                        iter.next()
                            .map(PathBuf::from)
                            .ok_or_else(|| "--readback-out requires a path".to_string())?,
                    );
                }
                "--readback-sequence-out" => {
                    readback_sequence_out =
                        Some(iter.next().map(PathBuf::from).ok_or_else(|| {
                            "--readback-sequence-out requires a path".to_string()
                        })?);
                }
                "--preview-roots" => {
                    preview_roots = iter
                        .next()
                        .ok_or_else(|| "--preview-roots requires a value".to_string())?
                        .parse()
                        .map_err(|_| "--preview-roots must be a non-zero integer".to_string())?;
                }
                "--legacy-camera-capture" => {
                    legacy_camera_capture =
                        Some(iter.next().map(PathBuf::from).ok_or_else(|| {
                            "--legacy-camera-capture requires a path".to_string()
                        })?);
                }
                "--static-animation-frame" => {
                    static_animation_frame = Some(
                        iter.next()
                            .ok_or_else(|| "--static-animation-frame requires a value".to_string())?
                            .parse()
                            .map_err(|_| {
                                "--static-animation-frame must be a u16 integer".to_string()
                            })?,
                    );
                }
                "--static-material-phase" => {
                    static_material_phase = Some(
                        iter.next()
                            .ok_or_else(|| "--static-material-phase requires a value".to_string())?
                            .parse()
                            .map_err(|_| {
                                "--static-material-phase must be a u16 integer".to_string()
                            })?,
                    );
                }
                _ => return Err(usage()),
            }
        }
        let root = root.ok_or_else(|| "missing --root".to_string())?;
        let mission = mission.ok_or_else(|| "missing --mission".to_string())?;
        if control_clock_ms.is_some() && frames < 2 {
            return Err(
                "--control-clock-ms requires --frames of at least 2 to replay the animation clock"
                    .to_string(),
            );
        }
        if readback_sequence_out.is_some() && control_clock_ms.is_none() {
            return Err(
                "--readback-sequence-out requires --control-clock-ms for a reproducible sequence"
                    .to_string(),
            );
        }
        Ok(Self {
            root,
            mission,
            frames,
            atmosphere_seconds,
            control_clock_ms,
            validation,
            readback_out,
            readback_sequence_out,
            preview_roots,
            legacy_camera_capture,
            static_animation_frame,
            static_material_phase,
        })
    }
}

#[derive(Clone, Debug, Deserialize, PartialEq)]
struct LegacyCameraCapture {
    schema: String,
    render_input_usable: Option<bool>,
    selector0_words: [u32; 16],
    parented_camera: Option<bool>,
    effective_world_matrix_space: Option<String>,
    effective_world_matrix_words: Option<[u32; 16]>,
    viewport: [i32; 4],
    near_plane: f32,
    far_plane: f32,
    field_of_view_radians: f32,
    atmosphere_seconds: Option<f32>,
}

fn selected_atmosphere_seconds(
    command_line: Option<f32>,
    capture: Option<&LegacyCameraCapture>,
) -> Option<f32> {
    command_line.or_else(|| capture.and_then(|capture| capture.atmosphere_seconds))
}

impl LegacyCameraCapture {
    fn preview_matrix_words(&self) -> Result<[u32; 16], String> {
        match (
            self.effective_world_matrix_space.as_deref(),
            self.effective_world_matrix_words,
        ) {
            (Some("world"), Some(words)) => Ok(words),
            (Some(_), _) => Err(
                "legacy camera effective_world_matrix_space must be 'world'".to_string(),
            ),
            (None, Some(_)) => Err(
                "legacy camera effective_world_matrix_words requires an explicit world-space marker"
                    .to_string(),
            ),
            (None, None) if self.parented_camera == Some(true) => Err(
                "parented legacy camera requires an effective world-space matrix".to_string(),
            ),
            (None, None) => Ok(self.selector0_words),
        }
    }

    fn captured_viewport(&self) -> Result<CapturedViewport, String> {
        let width = self.viewport[2]
            .checked_sub(self.viewport[0])
            .filter(|width| *width > 0)
            .ok_or_else(|| "legacy camera capture has an invalid viewport width".to_string())?;
        let height = self.viewport[3]
            .checked_sub(self.viewport[1])
            .filter(|height| *height > 0)
            .ok_or_else(|| "legacy camera capture has an invalid viewport height".to_string())?;
        Ok(CapturedViewport {
            rect: self.viewport,
            extent: [
                u32::try_from(width)
                    .map_err(|_| "legacy camera viewport width exceeds u32".to_string())?,
                u32::try_from(height)
                    .map_err(|_| "legacy camera viewport height exceeds u32".to_string())?,
            ],
        })
    }

    fn preview_camera_frame(&self) -> Result<PreviewCameraFrame, String> {
        let frame = PreviewCameraFrame::from_legacy_d3d7(
            RawCameraTransform {
                words: self.preview_matrix_words()?,
            },
            LegacyD3d7Projection {
                viewport: self.viewport,
                near_plane: self.near_plane,
                far_plane: self.far_plane,
                field_of_view_radians: self.field_of_view_radians,
            },
        )
        .ok_or_else(|| "legacy camera capture contains an invalid D3D7 camera".to_string())?;
        self.captured_viewport()?;
        Ok(frame)
    }
}

fn load_legacy_camera_capture(path: &std::path::Path) -> Result<LegacyCameraCapture, String> {
    let bytes = std::fs::read(path).map_err(|err| format!("{}: {err}", path.display()))?;
    parse_legacy_camera_capture(&bytes).map_err(|err| format!("{}: {err}", path.display()))
}

fn parse_legacy_camera_capture(bytes: &[u8]) -> Result<LegacyCameraCapture, String> {
    // Windows PowerShell 5.1 writes redirected text as UTF-16LE with a BOM.
    // `capture-original-camera.ps1` intentionally emits plain JSON, so accept
    // that normal hand-off format as well as UTF-8 without making the caller
    // re-encode a read-only capture file.
    let json = decode_legacy_camera_capture_json(bytes)?;
    let capture: LegacyCameraCapture =
        serde_json::from_str(&json).map_err(|err| format!("invalid legacy camera JSON: {err}"))?;
    if capture.schema != "fparkan-legacy-camera-v1" {
        return Err("unsupported legacy camera capture schema".to_string());
    }
    if capture.effective_world_matrix_space.is_some()
        != capture.effective_world_matrix_words.is_some()
    {
        return Err(
            "effective_world_matrix_space and effective_world_matrix_words must be supplied together"
                .to_string(),
        );
    }
    if capture.render_input_usable == Some(false) {
        return Err("legacy camera capture is marked render_input_usable=false".to_string());
    }
    if capture
        .atmosphere_seconds
        .is_some_and(|seconds| !seconds.is_finite() || seconds < 0.0)
    {
        return Err(
            "legacy camera capture atmosphere_seconds must be finite and non-negative".to_string(),
        );
    }
    capture.preview_camera_frame()?;
    Ok(capture)
}

fn decode_legacy_camera_capture_json(bytes: &[u8]) -> Result<String, String> {
    let decode_utf16 = |words: Vec<u16>| {
        String::from_utf16(&words)
            .map_err(|err| format!("invalid UTF-16 legacy camera JSON: {err}"))
    };
    match bytes {
        [0xff, 0xfe, rest @ ..] => {
            let chunks = rest.chunks_exact(2);
            if !chunks.remainder().is_empty() {
                return Err("invalid UTF-16LE legacy camera JSON length".to_string());
            }
            decode_utf16(
                chunks
                    .map(|chunk| u16::from_le_bytes([chunk[0], chunk[1]]))
                    .collect(),
            )
        }
        [0xfe, 0xff, rest @ ..] => {
            let chunks = rest.chunks_exact(2);
            if !chunks.remainder().is_empty() {
                return Err("invalid UTF-16BE legacy camera JSON length".to_string());
            }
            decode_utf16(
                chunks
                    .map(|chunk| u16::from_be_bytes([chunk[0], chunk[1]]))
                    .collect(),
            )
        }
        [0xef, 0xbb, 0xbf, rest @ ..] => std::str::from_utf8(rest)
            .map(str::to_owned)
            .map_err(|err| format!("invalid UTF-8 legacy camera JSON: {err}")),
        _ => std::str::from_utf8(bytes)
            .map(str::to_owned)
            .map_err(|err| format!("invalid UTF-8 legacy camera JSON: {err}")),
    }
}

fn usage() -> String {
    "usage: fparkan-game --root <path> --mission <path> [--frames <n>] [--atmosphere-seconds <seconds>] [--control-clock-ms <u32>] [--validation] [--preview-roots <non-zero n>] [--legacy-camera-capture <path>] [--static-animation-frame <u16>] [--static-material-phase <u16>] [--readback-out <path>] [--readback-sequence-out <directory>]\nstatic preview uses saved per-component CTLD defaults, with uncontrolled nodes at frame 0; --static-animation-frame overrides all components globally. --control-clock-ms replays one shared MSH/FX clock from zero to the selected time over the requested frames; --readback-sequence-out captures each submitted frame and requires that clock.".to_string()
}

#[cfg(test)]
mod tests {
    use super::*;
    use fparkan_animation::{AnimKey24, Pose};
    use fparkan_assets::{PreparedControlTimelineRow, PreparedControlTypedRecord};
    use fparkan_fx::environment::{WeatherInput, WeatherState};
    use fparkan_msh::{Batch, ModelAnimation, Slot};
    use fparkan_path::{normalize_relative, PathPolicy};
    use fparkan_resource::{resource_name, ResourceKey};

    fn facing_mesh(
        batch_flags: u16,
        positions: &[[f32; 3]],
    ) -> (VulkanStaticMesh, VulkanStaticDrawRange) {
        let range = VulkanStaticDrawRange {
            first_index: 0,
            index_count: u32::try_from(positions.len()).expect("fixture length fits u32"),
            material_index: 0,
            lightmap_index: 0,
            batch_flags,
            pipeline_state: LegacyPipelineState::default(),
            terrain_base_only: false,
            alpha_test_reference: VulkanStaticDrawRange::NATIVE_DEFAULT_ALPHA_TEST_REFERENCE,
        };
        let mesh = VulkanStaticMesh {
            vertices: positions
                .iter()
                .copied()
                .map(|position| VulkanStaticVertex {
                    position,
                    color: [1.0; 3],
                    normal: [0.0, 0.0, 1.0],
                    uv: [0.0; 2],
                    detail_uv: [0.0; 2],
                    overlay_alpha: 0.0,
                })
                .collect(),
            indices: (0..positions.len())
                .map(|index| u32::try_from(index).expect("fixture index fits u32"))
                .collect(),
            draw_ranges: vec![range],
        };
        (mesh, range)
    }

    fn native_front_triangle() -> [[f32; 3]; 3] {
        [[-0.2, -0.2, -1.0], [0.2, -0.2, -1.0], [0.0, 0.2, -1.0]]
    }

    fn camera_face_triangle(camera: PreviewCameraFrame, mirror: bool) -> [[f32; 3]; 3] {
        let center = add3(camera.position, scale3(camera.forward, 10.0));
        let mirror = if mirror { -1.0 } else { 1.0 };
        [
            add3(
                add3(center, scale3(camera.right, -2.0 * mirror)),
                scale3(camera.up, -2.0),
            ),
            add3(
                add3(center, scale3(camera.right, 2.0 * mirror)),
                scale3(camera.up, -2.0),
            ),
            add3(center, scale3(camera.up, 2.0)),
        ]
    }

    fn projected_vulkan_area(camera: PreviewCameraFrame, triangle: [[f32; 3]; 3]) -> f32 {
        let screen = triangle.map(|point| {
            let clip =
                row_vector_transform([point[0], point[1], point[2], 1.0], camera.clip_from_world);
            assert!(clip[3] > 0.0 && clip.iter().all(|value| value.is_finite()));
            // This is the positive-height viewport transform used by the Vulkan renderer.
            [
                (clip[0] / clip[3] + 1.0) * 0.5,
                (clip[1] / clip[3] + 1.0) * 0.5,
            ]
        });
        let shoelace = (0..3)
            .map(|index| {
                let next = (index + 1) % 3;
                screen[index][0] * screen[next][1] - screen[next][0] * screen[index][1]
            })
            .sum::<f32>()
            * 0.5;
        // Vulkan's framebuffer signed-area definition is the negative shoelace area.
        -shoelace
    }

    #[test]
    fn native_msh_cull_mode_matches_legacy_and_free_flight_camera_projection() {
        let identity = RawCameraTransform {
            words: [
                1.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                1.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                1.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                1.0_f32.to_bits(),
            ],
        };
        let projection = LegacyD3d7Projection {
            viewport: [0, 0, 1280, 1024],
            near_plane: 0.5,
            far_plane: 700.0,
            field_of_view_radians: 1.3,
        };
        let legacy = PreviewCameraFrame::from_legacy_d3d7(identity, projection)
            .expect("valid legacy camera projection");
        let free_flight = FreeFlightCamera {
            position: legacy.position,
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: 1.3,
            near_plane: 0.5,
            far_plane: 700.0,
            move_speed: 1.0,
            ground_clearance: 0.0,
        }
        .preview_frame(1280.0 / 1024.0);

        for camera in [legacy, free_flight] {
            let front = camera_face_triangle(camera, false);
            let back = [front[0], front[2], front[1]];
            let front_d = dot3(
                sub3(camera.position, front[0]),
                cross3(sub3(front[1], front[0]), sub3(front[2], front[0])),
            );
            let back_d = dot3(
                sub3(camera.position, back[0]),
                cross3(sub3(back[1], back[0]), sub3(back[2], back[0])),
            );
            assert!(front_d > 0.0);
            assert!(back_d < 0.0);

            let front_vk_area = projected_vulkan_area(camera, front);
            let back_vk_area = projected_vulkan_area(camera, back);
            // Vulkan CLOCKWISE front faces have negative framebuffer area.
            // The native-visible d>0 face is therefore a Vulkan back face.
            assert!(front_vk_area > 0.0, "front area: {front_vk_area}");
            assert!(back_vk_area < 0.0, "back area: {back_vk_area}");
            assert_eq!(native_msh_cull_mode(0, 1), LegacyCullMode::FrontFace);

            let mirrored_front = camera_face_triangle(camera, true);
            let mirrored_d = dot3(
                sub3(camera.position, mirrored_front[0]),
                cross3(
                    sub3(mirrored_front[1], mirrored_front[0]),
                    sub3(mirrored_front[2], mirrored_front[0]),
                ),
            );
            assert!(mirrored_d < 0.0);
            assert!(projected_vulkan_area(camera, mirrored_front) < 0.0);
            assert_eq!(native_msh_cull_mode(0, -1), LegacyCullMode::BackFace);
        }
    }

    #[test]
    fn native_msh_handedness_uses_full_placement_transform_and_handles_singular_scale() {
        let rotated = LegacyIron3dEulerTransform {
            translation: [8.0, -4.0, 3.0],
            orientation_radians: [0.4, -0.7, 1.2],
        };
        assert_eq!(native_msh_handedness(rotated, [2.0, 3.0, 4.0]), 1);
        assert_eq!(native_msh_handedness(rotated, [-2.0, 3.0, 4.0]), -1);
        assert_eq!(native_msh_handedness(rotated, [0.0, 3.0, 4.0]), 0);
        assert_eq!(native_msh_cull_mode(0, 0), LegacyCullMode::Disabled);
    }

    #[test]
    fn native_msh_4000_samples_only_first_triangle_and_raw_two_sided_bypasses_it() {
        let front = native_front_triangle();
        let back = front.map(|point| [-point[0], point[1], point[2]]);
        let front_then_back = [front[0], front[1], front[2], back[0], back[1], back[2]];
        let (mesh, range) = facing_mesh(0x4000, &front_then_back);
        assert!(native_msh_first_triangle_visible(
            &mesh, &range, [0.0; 3], 1
        ));

        let back_then_front = [back[0], back[1], back[2], front[0], front[1], front[2]];
        let (mesh, range) = facing_mesh(0x4000, &back_then_front);
        assert!(!native_msh_first_triangle_visible(
            &mesh, &range, [0.0; 3], 1
        ));

        let (mesh, range) = facing_mesh(0x4002, &back_then_front);
        assert!(native_msh_first_triangle_visible(
            &mesh, &range, [0.0; 3], 1
        ));
        assert_eq!(
            native_msh_cull_mode(range.batch_flags, 1),
            LegacyCullMode::Disabled
        );
    }

    #[test]
    fn world_draw_range_count_restores_after_alpha_and_msh_facing_changes() {
        let triangle = native_front_triangle();
        let (mesh, range) = facing_mesh(0x4000, &triangle);
        let original_count = range.index_count;

        assert_eq!(
            world_draw_range_index_count(&mesh, &range, original_count, 0.0, [0.0; 3], Some(1)),
            0
        );
        assert_eq!(
            world_draw_range_index_count(
                &mesh,
                &range,
                original_count,
                1.0,
                [0.0, 0.0, -2.0],
                Some(1),
            ),
            0
        );
        assert_eq!(
            world_draw_range_index_count(&mesh, &range, original_count, 1.0, [0.0; 3], Some(1)),
            original_count
        );
        assert_eq!(
            world_draw_range_index_count(
                &mesh,
                &range,
                original_count,
                1.0,
                [0.0, 0.0, -2.0],
                None,
            ),
            original_count
        );
    }

    #[test]
    fn world_draw_range_count_clears_and_reapplies_constant_alpha_override() {
        let triangle = native_front_triangle();
        let (mesh, mut range) = facing_mesh(0x0148, &triangle);
        let original_count = range.index_count;
        let mut alpha_override = None;
        let update = |range: &VulkanStaticDrawRange, alpha_override: &mut Option<f32>| {
            *alpha_override = native_msh_diffuse_alpha_override(range.batch_flags, false);
            world_draw_range_index_count(
                &mesh,
                range,
                original_count,
                alpha_override.unwrap_or(1.0),
                [0.0; 3],
                None,
            )
        };

        assert_eq!(update(&range, &mut alpha_override), 0);
        range.batch_flags = 0x0108;
        assert_eq!(update(&range, &mut alpha_override), original_count);
        range.batch_flags = 0x0148;
        assert_eq!(update(&range, &mut alpha_override), 0);
        assert_eq!(original_count, 3);
    }

    fn identity_matrix() -> [[f32; 4]; 4] {
        [
            [1.0, 0.0, 0.0, 0.0],
            [0.0, 1.0, 0.0, 0.0],
            [0.0, 0.0, 1.0, 0.0],
            [0.0, 0.0, 0.0, 1.0],
        ]
    }

    fn node38_fixture(parent: u16, map_start: u16, fallback: u16, drawable: bool) -> Vec<u8> {
        let mut node = Vec::with_capacity(38);
        node.extend_from_slice(&[0, 0]);
        node.extend_from_slice(&parent.to_le_bytes());
        node.extend_from_slice(&map_start.to_le_bytes());
        node.extend_from_slice(&fallback.to_le_bytes());
        for slot in 0..15 {
            let value = if drawable && slot == 0 { 0 } else { u16::MAX };
            node.extend_from_slice(&value.to_le_bytes());
        }
        node
    }

    fn animated_socket_model() -> ModelAsset {
        let mut nodes = node38_fixture(u16::MAX, 0, 1, true);
        nodes.extend(node38_fixture(0, u16::MAX, 2, false));
        ModelAsset {
            node_stride: 38,
            node_count: 2,
            nodes_raw: nodes,
            bounding_sphere_center: [0.0; 3],
            bounding_sphere_radius: 2.0,
            slots: vec![Slot {
                tri_start: 0,
                tri_count: 1,
                batch_start: 0,
                batch_count: 1,
                aabb_min: [-1.0; 3],
                aabb_max: [1.0; 3],
                sphere_center: [0.0; 3],
                sphere_radius: 1.0,
                opaque: [0; 5],
            }],
            positions: vec![[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]],
            normals: Some(vec![[127, 0, 0, 0]; 3]),
            uv0: None,
            uv1: None,
            type16_present: false,
            indices: vec![0, 1, 2],
            batches: vec![Batch {
                batch_flags: 0,
                material_index_hi: 0,
                material_index: 0,
                lightmap_index: 0,
                local_batch_index: 0,
                index_count: 3,
                index_start: 0,
                vertex_count: 3,
                base_vertex: 0,
            }],
            triangle_descriptors: None,
            node_names: None,
            animation: Some(ModelAnimation {
                keys: vec![
                    AnimKey24 {
                        time: AnimationTime(0.0),
                        pose: Pose::default(),
                    },
                    AnimKey24 {
                        time: AnimationTime(1.0),
                        pose: Pose {
                            translation: [0.0; 3],
                            rotation: [
                                0.0,
                                0.0,
                                std::f32::consts::FRAC_1_SQRT_2,
                                std::f32::consts::FRAC_1_SQRT_2,
                            ],
                        },
                    },
                    AnimKey24 {
                        time: AnimationTime(0.0),
                        pose: Pose {
                            translation: [0.0, 2.0, 0.0],
                            rotation: [0.0, 0.0, 0.0, 1.0],
                        },
                    },
                ],
                frame_map: vec![0, 1],
                frame_count: 2,
            }),
        }
    }

    fn static_child_model() -> ModelAsset {
        let mut nodes = node38_fixture(u16::MAX, u16::MAX, 0, false);
        nodes.extend(node38_fixture(0, u16::MAX, 0, true));
        ModelAsset {
            node_stride: 38,
            node_count: 2,
            nodes_raw: nodes,
            bounding_sphere_center: [0.0; 3],
            bounding_sphere_radius: 1.0,
            slots: vec![Slot {
                tri_start: 0,
                tri_count: 1,
                batch_start: 0,
                batch_count: 1,
                aabb_min: [-1.0; 3],
                aabb_max: [1.0; 3],
                sphere_center: [0.0; 3],
                sphere_radius: 1.0,
                opaque: [0; 5],
            }],
            positions: vec![[0.0, 0.0, 0.0]; 3],
            normals: Some(vec![[0, 0, 127, 0]; 3]),
            uv0: None,
            uv1: None,
            type16_present: false,
            indices: vec![0, 1, 2],
            batches: vec![Batch {
                batch_flags: 0,
                material_index_hi: 0,
                material_index: 0,
                lightmap_index: 0,
                local_batch_index: 0,
                index_count: 3,
                index_start: 0,
                vertex_count: 3,
                base_vertex: 0,
            }],
            triangle_descriptors: None,
            node_names: None,
            animation: Some(ModelAnimation {
                keys: vec![AnimKey24 {
                    time: AnimationTime(0.0),
                    pose: Pose::default(),
                }],
                frame_map: vec![],
                frame_count: 0,
            }),
        }
    }

    fn collision_fixture_model(root_drawable: bool) -> ModelAsset {
        let mut nodes = node38_fixture(u16::MAX, u16::MAX, 0, root_drawable);
        nodes.extend(node38_fixture(0, 0, 1, true));
        ModelAsset {
            node_stride: 38,
            node_count: 2,
            nodes_raw: nodes,
            bounding_sphere_center: [0.0; 3],
            bounding_sphere_radius: 3.0,
            slots: vec![Slot {
                tri_start: 0,
                tri_count: 1,
                batch_start: 0,
                batch_count: 1,
                aabb_min: [-2.0, 0.0, -2.0],
                aabb_max: [2.0, 0.0, 2.0],
                sphere_center: [0.0; 3],
                sphere_radius: 2.0,
                opaque: [0; 5],
            }],
            positions: vec![[-2.0, 0.0, -2.0], [0.0, 0.0, 2.0], [2.0, 0.0, -2.0]],
            normals: Some(vec![[0, 127, 0, 0]; 3]),
            uv0: None,
            uv1: None,
            type16_present: false,
            indices: vec![0, 1, 2],
            batches: vec![Batch {
                batch_flags: 0,
                material_index_hi: 0,
                material_index: 0,
                lightmap_index: 0,
                local_batch_index: 0,
                index_count: 3,
                index_start: 0,
                vertex_count: 3,
                base_vertex: 0,
            }],
            triangle_descriptors: Some(vec![fparkan_msh::TriangleDescriptor {
                tri_flags: 0,
                opaque: [0; 4],
                normal: [0, 32767, 0],
            }]),
            node_names: None,
            animation: Some(ModelAnimation {
                keys: vec![
                    AnimKey24 {
                        time: AnimationTime(0.0),
                        pose: Pose::default(),
                    },
                    AnimKey24 {
                        time: AnimationTime(1.0),
                        pose: Pose {
                            translation: [20.0, 0.0, 0.0],
                            rotation: [0.0, 0.0, 0.0, 1.0],
                        },
                    },
                ],
                frame_map: vec![0, 1],
                frame_count: 2,
            }),
        }
    }

    #[test]
    fn mounted_static_building_binding_matches_renderer_and_hides_root_node() {
        let model = collision_fixture_model(true);
        let binding = building_collision_binding(
            4,
            5,
            "static fixture model".to_string(),
            Arc::new(model.clone()),
            LegacyIron3dEulerTransform {
                translation: [13.0, -4.0, 9.0],
                orientation_radians: [0.4, -0.3, 0.7],
            },
            [2.0, 3.0, 0.5],
            true,
        )
        .expect("static building geometry still creates a collision binding");
        assert_eq!(
            binding.selected_nodes,
            vec![(fparkan_msh::NodeId(1), fparkan_msh::SlotId(0))]
        );

        let root = VulkanNodePose {
            translation: [1.0, 2.0, 3.0],
            rotation: [0.0, 0.0, 0.29552022, 0.9553365],
        };
        let moving_node = compose_unit_pose(
            root,
            VulkanNodePose {
                translation: [2.0, -1.0, 0.5],
                rotation: [0.0, 0.19866933, 0.0, 0.9800666],
            },
        );
        let hierarchy = NodePoseBuffer {
            poses: [root, moving_node]
                .into_iter()
                .map(|pose| Pose {
                    translation: pose.translation,
                    rotation: pose.rotation,
                })
                .collect(),
        };
        let mount = VulkanNodePose {
            translation: [5.0, 7.0, 11.0],
            rotation: [0.0, 0.0, 0.38268343, 0.9238795],
        };
        let nodes = building_collision_nodes(&binding, Some(&hierarchy), Some(mount))
            .expect("mounted collision matrices");
        assert_eq!(nodes.len(), 1);
        assert_eq!(nodes[0].node, fparkan_msh::NodeId(1));

        let projected = project_msh_to_static_mesh_in_world_space_with_node_pose_buffer_and_mount(
            &model,
            binding.root_transform,
            binding.owner_scale,
            &hierarchy,
            mount,
        )
        .expect("mounted renderer projection");
        assert_eq!(projected.vertices.len(), 3);
        for (actual, source) in projected.vertices.iter().zip(&model.positions) {
            let matrix = nodes[0].world_from_node;
            let expected = [
                matrix[0] * source[0] + matrix[1] * source[1] + matrix[2] * source[2] + matrix[3],
                matrix[4] * source[0] + matrix[5] * source[1] + matrix[6] * source[2] + matrix[7],
                matrix[8] * source[0] + matrix[9] * source[1] + matrix[10] * source[2] + matrix[11],
            ];
            for axis in 0..3 {
                assert!((actual.position[axis] - expected[axis]).abs() < 1.0e-4);
            }
        }
    }

    fn doorway_collision_model() -> ModelAsset {
        let mut nodes = node38_fixture(u16::MAX, u16::MAX, 0, false);
        nodes.extend(node38_fixture(0, u16::MAX, 0, true));
        ModelAsset {
            node_stride: 38,
            node_count: 2,
            nodes_raw: nodes,
            bounding_sphere_center: [0.0; 3],
            bounding_sphere_radius: 5.0,
            slots: vec![Slot {
                tri_start: 0,
                tri_count: 4,
                batch_start: 0,
                batch_count: 1,
                aabb_min: [-4.0, 0.0, -2.0],
                aabb_max: [4.0, 0.0, 2.0],
                sphere_center: [0.0; 3],
                sphere_radius: 5.0,
                opaque: [0; 5],
            }],
            positions: vec![
                [-4.0, 0.0, -2.0],
                [-1.0, 0.0, -2.0],
                [-1.0, 0.0, 2.0],
                [-4.0, 0.0, 2.0],
                [1.0, 0.0, -2.0],
                [4.0, 0.0, -2.0],
                [4.0, 0.0, 2.0],
                [1.0, 0.0, 2.0],
            ],
            normals: None,
            uv0: None,
            uv1: None,
            type16_present: false,
            indices: vec![0, 3, 2, 0, 2, 1, 4, 7, 6, 4, 6, 5],
            batches: vec![Batch {
                batch_flags: 0,
                material_index_hi: 0,
                material_index: 0,
                lightmap_index: 0,
                local_batch_index: 0,
                index_count: 12,
                index_start: 0,
                vertex_count: 8,
                base_vertex: 0,
            }],
            triangle_descriptors: Some(
                (0..4)
                    .map(|_| fparkan_msh::TriangleDescriptor {
                        tri_flags: 0,
                        opaque: [0; 4],
                        normal: [0, 32767, 0],
                    })
                    .collect(),
            ),
            node_names: None,
            animation: Some(ModelAnimation {
                keys: vec![AnimKey24 {
                    time: AnimationTime(0.0),
                    pose: Pose::default(),
                }],
                frame_map: Vec::new(),
                frame_count: 0,
            }),
        }
    }

    fn collision_test_app(
        model: Arc<ModelAsset>,
        root_transform: LegacyIron3dEulerTransform,
        position: [f32; 3],
    ) -> StaticVulkanApp {
        let (mut app, _) = clock_test_app(None);
        let hierarchy = static_preview_component_pose_buffer(&model, &[], None)
            .expect("fixture static preview pose")
            .expect("fixture Node38 pose");
        app.component_pose_buffers = vec![vec![Some(hierarchy)]];
        app.component_mount_poses = vec![vec![None]];
        app.dynamic_component_geometry = vec![vec![None]];
        app.control_animation_instances = vec![vec![None]];
        app.building_collision_bindings = vec![building_collision_binding(
            0,
            0,
            "collision fixture".to_string(),
            Arc::clone(&model),
            root_transform,
            [1.0; 3],
            false,
        )
        .expect("fixture building collision binding")];
        app.free_camera = Some(FreeFlightCamera {
            position,
            yaw: -std::f32::consts::FRAC_PI_2,
            pitch: 0.0,
            horizontal_fov: 1.3,
            near_plane: 0.5,
            far_plane: 700.0,
            move_speed: 60.0,
            ground_clearance: 0.0,
        });
        app.pressed_keys.insert(KeyCode::KeyW);
        app
    }

    #[test]
    fn high_speed_free_flight_stops_at_static_building_wall() {
        let mut app = collision_test_app(
            Arc::new(collision_fixture_model(false)),
            LegacyIron3dEulerTransform {
                translation: [0.0, 5.0, 0.0],
                orientation_radians: [0.0; 3],
            },
            [0.0, 8.0, 0.0],
        );
        app.update_free_camera(0.1, [1280.0, 720.0])
            .expect("continuous building query");
        assert_eq!(app.free_camera.unwrap().position, [0.0, 8.0, 0.0]);
    }

    #[test]
    fn small_nonzero_building_scale_remains_queryable() {
        let model = Arc::new(collision_fixture_model(false));
        let binding = building_collision_binding(
            0,
            0,
            "tiny-scale fixture".to_string(),
            Arc::clone(&model),
            LegacyIron3dEulerTransform {
                translation: [0.0, 5.0, 0.0],
                orientation_radians: [0.0; 3],
            },
            [1.0e-8, 1.0, 1.0],
            false,
        )
        .expect("small nonzero scale is invertible");
        let hierarchy = static_preview_component_pose_buffer(&model, &[], None)
            .expect("fixture static preview pose")
            .expect("fixture Node38 pose");
        let nodes = building_collision_nodes(&binding, Some(&hierarchy), None)
            .expect("small-scale collision matrix");
        assert!(query_building_segment_world(
            &binding.model,
            &nodes,
            [[0.0, 8.0, 0.0], [0.0, 2.0, 0.0]],
        )
        .expect("small-scale query")
        .is_some());
    }

    #[test]
    fn free_flight_passes_through_authored_doorway() {
        let mut app = collision_test_app(
            Arc::new(doorway_collision_model()),
            LegacyIron3dEulerTransform {
                translation: [0.0, 5.0, 0.0],
                orientation_radians: [0.0; 3],
            },
            [0.0, 8.0, 0.0],
        );
        app.update_free_camera(0.1, [1280.0, 720.0])
            .expect("doorway query");
        let position = app.free_camera.unwrap().position;
        assert!((position[1] - 2.0).abs() < 1.0e-4);
    }

    #[test]
    fn shared_building_models_keep_each_placed_instance_query_separate() {
        let model = Arc::new(collision_fixture_model(false));
        let far = building_collision_binding(
            0,
            0,
            "shared fixture".to_string(),
            Arc::clone(&model),
            LegacyIron3dEulerTransform {
                translation: [0.0, 100.0, 0.0],
                orientation_radians: [0.0; 3],
            },
            [1.0; 3],
            false,
        )
        .expect("first placed building");
        let near = building_collision_binding(
            1,
            0,
            "shared fixture".to_string(),
            Arc::clone(&model),
            LegacyIron3dEulerTransform {
                translation: [0.0, 5.0, 0.0],
                orientation_radians: [0.0; 3],
            },
            [1.0; 3],
            false,
        )
        .expect("second placed building");
        assert!(Arc::ptr_eq(&far.model, &near.model));

        let (mut app, _) = clock_test_app(None);
        let hierarchy = static_preview_component_pose_buffer(&model, &[], None)
            .expect("shared fixture static pose")
            .expect("shared fixture Node38 pose");
        app.component_pose_buffers = vec![vec![Some(hierarchy.clone())], vec![Some(hierarchy)]];
        app.component_mount_poses = vec![vec![None], vec![None]];
        app.building_collision_bindings = vec![far, near];
        app.free_camera.as_mut().unwrap().position = [0.0, 8.0, 0.0];
        app.free_camera.as_mut().unwrap().yaw = -std::f32::consts::FRAC_PI_2;
        app.free_camera.as_mut().unwrap().pitch = 0.0;
        app.free_camera.as_mut().unwrap().move_speed = 60.0;
        app.pressed_keys.insert(KeyCode::KeyW);
        app.update_free_camera(0.1, [1280.0, 720.0])
            .expect("both placed buildings are queried independently");
        assert_eq!(app.free_camera.unwrap().position, [0.0, 8.0, 0.0]);
    }

    #[test]
    fn collision_uses_updated_control_pose_and_retries_do_not_move_again() {
        let model = Arc::new(collision_fixture_model(false));
        let mut app = collision_test_app(
            Arc::clone(&model),
            LegacyIron3dEulerTransform {
                translation: [0.0, 5.0, 0.0],
                orientation_radians: [0.0; 3],
            },
            [0.0, 8.0, 0.0],
        );
        let mut control = socket_timeline_control();
        control.timeline_rows[0].node_index = 1;
        app.control_animation_instances[0][0] = Some(ControlAnimationInstance {
            control,
            model: (*model).clone(),
            gate_values: vec![Some(0.0)],
            state: ControlInstanceState::default(),
            last_sampled_node_times: Vec::new(),
            reported_unsupported_fallback: false,
        });

        let first = FrameClockSample {
            id: SceneSampleId::Replay(0),
            time_ms: 0,
            delta_seconds: 0.1,
        };
        app.prepare_scene_update(first, [1280.0, 720.0])
            .expect("closed moving wall blocks the first frame");
        let safe_position = app.free_camera.unwrap().position;
        let closed_pose = app.component_pose_buffers[0][0].as_ref().unwrap().poses[1].translation;
        assert_eq!(safe_position, [0.0, 8.0, 0.0]);

        app.control_animation_instances[0][0]
            .as_mut()
            .unwrap()
            .gate_values[0] = Some(1.0);
        app.prepare_scene_update(first, [1024.0, 768.0])
            .expect("pending retry only refreshes its viewport");
        assert_eq!(app.free_camera.unwrap().position, safe_position);
        assert_eq!(
            app.component_pose_buffers[0][0].as_ref().unwrap().poses[1].translation,
            closed_pose
        );

        app.prepare_scene_update(
            FrameClockSample {
                id: SceneSampleId::Replay(1),
                time_ms: 1000,
                delta_seconds: 0.1,
            },
            [1024.0, 768.0],
        )
        .expect("the next sampled pose opens the path");
        let open_pose = app.component_pose_buffers[0][0].as_ref().unwrap().poses[1].translation;
        assert!(open_pose[0] > 2.0, "door node did not move: {open_pose:?}");
        assert!((app.free_camera.unwrap().position[1] - 2.0).abs() < 1.0e-4);
    }

    #[test]
    fn missing_free_camera_keeps_legacy_view_without_querying_buildings() {
        let (mut app, _) = clock_test_app(None);
        app.free_camera = None;
        app.building_collision_bindings
            .push(BuildingCollisionBinding {
                object_index: 0,
                component_index: 0,
                model_source: "legacy fixture".to_string(),
                model: Arc::new(collision_fixture_model(false)),
                root_transform: LegacyIron3dEulerTransform {
                    translation: [0.0; 3],
                    orientation_radians: [0.0; 3],
                },
                owner_scale: [1.0; 3],
                mounted: false,
                selected_nodes: vec![(NodeId(u32::MAX), SlotId(u32::MAX))],
            });
        let camera = app.camera;
        let view_camera = app.view_camera;
        app.update_free_camera(0.1, [1024.0, 768.0])
            .expect("legacy camera skips free-flight collision");
        assert_eq!(app.camera, camera);
        assert_eq!(app.view_camera, view_camera);
    }

    #[test]
    #[ignore = "requires licensed corpus"]
    fn licensed_plant_wall_and_door_use_the_app_camera_bridge() {
        use std::path::PathBuf;

        const BODY_WALL: [[f32; 3]; 2] = [[-10.5, 22.16, 2.5], [-10.5, 19.16, 2.5]];
        const BODY_DOOR: [[f32; 3]; 2] = [[0.5, 22.16, 2.5], [0.5, 19.16, 2.5]];
        let root = PathBuf::from(
            std::env::var_os("FPARKAN_CORPUS_PART1_ROOT")
                .expect("FPARKAN_CORPUS_PART1_ROOT is required for licensed tests"),
        );
        let mission = "MISSIONS/Autodemo.00/data.tma";
        let args = Args::parse(&[
            "--root".to_string(),
            root.to_string_lossy().into_owned(),
            "--mission".to_string(),
            mission.to_string(),
        ])
        .expect("licensed AutoDemo app arguments");
        let mut engine = create(EngineServices::new(Arc::new(DirectoryVfs::new(&args.root))))
            .expect("create licensed AutoDemo engine");
        let loaded = load_requested_mission(&mut engine, &args).expect("load AutoDemo mission");
        let assets = loaded_mission_assets(&engine).expect("AutoDemo assets");
        let terrain = loaded_terrain(&engine).expect("AutoDemo terrain");
        let roots = loaded_mission_object_drafts(&engine).expect("AutoDemo object drafts");
        let preview = static_preview_mesh_and_materials(
            assets,
            terrain,
            roots,
            None,
            None,
            None,
            &args.root,
            &loaded.land_msh_path,
        )
        .expect("build AutoDemo static preview");
        let mut component_bindings = preview
            .building_collision_bindings
            .iter()
            .map(|binding| (binding.object_index, binding.component_index))
            .collect::<Vec<_>>();
        component_bindings.sort_unstable();
        assert_eq!(
            component_bindings,
            vec![(4, 0), (4, 5), (5, 0), (5, 5), (6, 0), (7, 0)]
        );

        let shadow_range = EnvironmentGpuRange {
            range_index: preview.mesh.draw_ranges.len(),
            vertex_start: 0,
            vertex_capacity: 0,
            material_index: preview.shadow_material_index,
        };
        let mut app = StaticVulkanApp::new(
            preview,
            None,
            None,
            shadow_range,
            0,
            0,
            None,
            2,
            mission,
            loaded.object_count,
            None,
            None,
            false,
            None,
            StartupTimings::default(),
        );
        let plant = app
            .building_collision_bindings
            .iter()
            .find(|binding| binding.object_index == 4 && binding.component_index == 0)
            .cloned()
            .expect("static PLANT root collision binding");
        let hierarchy = app.component_pose_buffers[4][0]
            .as_ref()
            .expect("PLANT current root pose");
        let plant_nodes =
            building_collision_nodes(&plant, Some(hierarchy), app.component_mount_poses[4][0])
                .expect("PLANT current collision nodes");
        let plant_node = plant_nodes
            .iter()
            .copied()
            .find(|node| node.node == NodeId(1) && node.slot == SlotId(0))
            .expect("native fixture node and slot");
        let body_to_world = |point| {
            plant
                .root_transform
                .try_transform_scaled_point(point, plant.owner_scale)
                .expect("finite placed-body transform")
        };
        let world_wall = BODY_WALL.map(body_to_world);
        let world_door = BODY_DOOR.map(body_to_world);
        let direct_wall_hit = query_building_segment_world(&plant.model, &[plant_node], world_wall)
            .expect("direct PLANT body-space query")
            .expect("verified PLANT wall hit");
        assert_eq!(direct_wall_hit.node, NodeId(1));
        assert_eq!(direct_wall_hit.slot, SlotId(0));
        assert_eq!(direct_wall_hit.batch_index, 5);
        assert_eq!(direct_wall_hit.triangle_descriptor_index, 62);
        let closed_door_hit = query_building_segment_world(&plant.model, &plant_nodes, world_door)
            .expect("linked PLANT door query")
            .expect("the default Node3 door blocks the center path");
        assert_eq!(closed_door_hit.node, NodeId(3));
        assert_eq!(closed_door_hit.batch_index, 100);
        assert_eq!(closed_door_hit.triangle_descriptor_index, 855);
        let terrain_bounds = app
            .terrain
            .surface_bounds()
            .expect("AutoDemo terrain surface bounds");
        for point in world_wall.into_iter().chain(world_door) {
            for axis in 0..2 {
                assert!(
                    (terrain_bounds[0][axis]..=terrain_bounds[1][axis]).contains(&point[axis]),
                    "native fixture endpoint {point:?} is outside terrain bounds {terrain_bounds:?}"
                );
            }
            let floor = app
                .terrain
                .height_at([point[0], point[1]])
                .expect("fixture terrain query");
            if let Some(floor) = floor {
                assert!(
                    point[2] >= floor,
                    "native fixture height {} is below terrain {floor} at {point:?}",
                    point[2]
                );
            } else {
                let foundation = app
                    .terrain
                    .basement_foundation()
                    .expect("missing terrain height needs a BAS foundation");
                assert!(!foundation.fragments.is_empty());
                let source_floor = terrain
                    .height_at([point[0], point[1]])
                    .expect("source fixture terrain query")
                    .expect("BAS-cut fixture endpoint has source Land.msh terrain");
                eprintln!(
                    "native fixture endpoint {point:?} has source Land.msh floor {source_floor} but no BAS-foundation surface"
                );
            }
            let mut constrained = FreeFlightCamera {
                position: point,
                yaw: 0.0,
                pitch: 0.0,
                horizontal_fov: 1.3,
                near_plane: 0.5,
                far_plane: 700.0,
                move_speed: 0.0,
                ground_clearance: 0.0,
            };
            constrained
                .keep_above_terrain(&app.terrain)
                .expect("terrain constraint preserves native fixture height");
            assert_eq!(constrained.position, point);
        }

        set_collision_test_segment(&mut app, world_wall);
        let zero_delta = FrameClockSample {
            id: SceneSampleId::Replay(0),
            time_ms: 0,
            delta_seconds: 0.0,
        };
        app.prepare_scene_update(zero_delta, [1280.0, 720.0])
            .expect("zero-delta resume initialization");
        assert_eq!(app.free_camera.unwrap().position, world_wall[0]);
        assert_eq!(app.record_presented_scene_frame(), 0);

        let wall_frame = FrameClockSample {
            id: SceneSampleId::Replay(1),
            time_ms: 0,
            delta_seconds: 0.1,
        };
        app.prepare_scene_update(wall_frame, [1280.0, 720.0])
            .expect("high-speed wall movement through the app update path");
        assert_eq!(app.free_camera.unwrap().position, world_wall[0]);
        app.pressed_keys.clear();
        app.pressed_keys.insert(KeyCode::KeyD);
        app.prepare_scene_update(wall_frame, [1024.0, 768.0])
            .expect("retry of the pending wall frame");
        assert_eq!(app.free_camera.unwrap().position, world_wall[0]);
        assert_eq!(app.record_presented_scene_frame(), 1);

        set_collision_test_segment(&mut app, world_door);
        app.prepare_scene_update(
            FrameClockSample {
                id: SceneSampleId::Replay(2),
                time_ms: 0,
                delta_seconds: 0.1,
            },
            [1024.0, 768.0],
        )
        .expect("the closed Node3 door blocks through the app update path");
        assert_eq!(app.free_camera.unwrap().position, world_door[0]);
        assert_eq!(app.record_presented_scene_frame(), 2);

        let control = assets
            .object_component_controls
            .get(4)
            .and_then(|components| components.first())
            .and_then(Option::as_ref)
            .expect("PLANT root retains its CTLD control");
        let node3_binding = control
            .bindings
            .iter()
            .find(|binding| binding.node_index == 3)
            .expect("PLANT CTLD binding for the authored Node3 door");
        assert_eq!(node3_binding.frame_a, 0.0);
        assert_eq!(node3_binding.frame_b, 1.0);
        assert_eq!(node3_binding.initial_blend, 0.0);
        assert_eq!(
            control
                .typed_records
                .iter()
                .filter(|record| record.tag == 21)
                .count(),
            0,
            "the PLANT control has no tag-21 record to advance Node3 from its initial frame"
        );
        let mut open_node_times =
            static_preview_node_times(plant.model.node_count, &control.bindings)
                .expect("actual initial PLANT CTLD node times");
        assert_eq!(open_node_times[3], Some(AnimationTime(0.0)));
        // This samples the door's authored frame B directly; it does not simulate a mission gate.
        open_node_times[3] = Some(AnimationTime(1.0));
        let open_hierarchy = node38_sampled_hierarchy_at_times(&plant.model, &open_node_times)
            .expect("sample the actual PLANT model at its authored Node3 frame B");
        app.component_pose_buffers[4][0] = Some(open_hierarchy);
        update_dynamic_component_geometry(
            &app.dynamic_component_geometry,
            &app.component_pose_buffers,
            &mut app.component_mount_poses,
            &mut app.mesh,
        )
        .expect("update the scene hierarchy for the authored door pose");
        let open_hierarchy = app.component_pose_buffers[4][0]
            .as_ref()
            .expect("sampled PLANT root pose");
        let open_nodes = building_collision_nodes(
            &plant,
            Some(open_hierarchy),
            app.component_mount_poses[4][0],
        )
        .expect("sampled PLANT collision nodes");
        assert!(
            query_building_segment_world(&plant.model, &open_nodes, world_door)
                .expect("open PLANT door query")
                .is_none(),
            "the authored Node3 time-1 pose leaves the doorway ray clear"
        );

        set_collision_test_segment(&mut app, world_door);
        app.update_free_camera(0.1, [1024.0, 768.0])
            .expect("open doorway movement through the app camera update");
        let position = app.free_camera.unwrap().position;
        for axis in 0..3 {
            assert!((position[axis] - world_door[1][axis]).abs() < 1.0e-4);
        }
    }

    fn set_collision_test_segment(app: &mut StaticVulkanApp, segment: [[f32; 3]; 2]) {
        let delta = sub3(segment[1], segment[0]);
        let horizontal_distance = (delta[0] * delta[0] + delta[1] * delta[1]).sqrt();
        app.free_camera = Some(FreeFlightCamera {
            position: segment[0],
            yaw: delta[1].atan2(delta[0]),
            pitch: delta[2].atan2(horizontal_distance),
            horizontal_fov: 1.3,
            near_plane: 0.5,
            far_plane: 700.0,
            move_speed: length3(delta).expect("nonzero native test segment") / 0.1,
            ground_clearance: 0.0,
        });
        app.pressed_keys.clear();
        app.pressed_keys.insert(KeyCode::KeyW);
    }

    fn socket_timeline_control() -> PreparedComponentControl {
        let mut fixed_words = [0; 44];
        fixed_words[2] = 0;
        fixed_words[6] = u32::MAX;
        fixed_words[9] = 1.0_f32.to_bits();
        fixed_words[10] = 1.0_f32.to_bits();
        PreparedComponentControl {
            source: ResourceKey {
                archive: normalize_relative(b"test.rlb", PathPolicy::HostCompatible)
                    .expect("archive path"),
                name: resource_name(b"animated.ctl"),
                type_id: None,
            },
            native_profile_words: [0; 27],
            model_node_count: 2,
            bindings: vec![],
            timeline_rows: vec![PreparedControlTimelineRow {
                row_index: 0,
                node_index: 0,
                frame_a: 0.0,
                frame_b: 1.0,
                initial_blend: 0.0,
                raw_parameters: [u32::MAX, u32::MAX, 1.0_f32.to_bits(), 0],
                flags: 0,
            }],
            typed_records: vec![PreparedControlTypedRecord {
                tag: 21,
                fixed_words,
                values: vec![0],
                string_bytes: vec![],
                gate_provider: PreparedControlGateProvider::Resolved {
                    key: 0,
                    ndp_source: ResourceKey {
                        archive: normalize_relative(b"test.rlb", PathPolicy::HostCompatible)
                            .expect("NDP archive path"),
                        name: resource_name(b"animated.ndp"),
                        type_id: None,
                    },
                    row_count: 1,
                    initial_type1_value: 1.0,
                },
            }],
            node_data: None,
            effect_section: PreparedControlEffectSection::Absent,
            initial_effect_group: None,
            point_list: None,
        }
    }

    fn control_point(position: [f32; 3], direction: [f32; 3]) -> PreparedControlPoint {
        PreparedControlPoint {
            raw_flags: 0,
            raw_signed_field_04: 0,
            raw_signed_field_08: 0,
            position,
            direction,
            name: [0; 32],
        }
    }

    fn assert_matrix_columns(matrix: [[f32; 4]; 4], expected: [[f32; 3]; 3]) {
        for (column, expected) in expected.into_iter().enumerate() {
            for row in 0..3 {
                assert!(
                    (matrix[row][column] - expected[row]).abs() < 1.0e-5,
                    "column {column} row {row}: {} != {}",
                    matrix[row][column],
                    expected[row]
                );
            }
        }
    }

    fn write_effect_u32(body: &mut [u8], offset: usize, value: u32) {
        body[offset..offset + 4].copy_from_slice(&value.to_le_bytes());
    }

    fn write_effect_f32(body: &mut [u8], offset: usize, value: f32) {
        body[offset..offset + 4].copy_from_slice(&value.to_le_bytes());
    }

    fn write_effect_vec3(body: &mut [u8], offset: usize, value: [f32; 3]) {
        for (axis, component) in value.into_iter().enumerate() {
            write_effect_f32(body, offset + axis * 4, component);
        }
    }

    #[test]
    fn tag21_clock_moves_msh_vertices_normals_child_socket_and_fx_anchor() {
        let parent_model = animated_socket_model();
        let child_model = static_child_model();
        let identity_transform = LegacyIron3dEulerTransform {
            translation: [0.0; 3],
            orientation_radians: [0.0; 3],
        };
        let initial_parent_pose =
            node38_sampled_hierarchy_at_times(&parent_model, &[Some(AnimationTime(0.0)), None])
                .expect("initial parent pose");
        let initial_child_pose =
            node38_fallback_hierarchy(&child_model).expect("static child pose");
        let initial_mount =
            node38_pose_from_hierarchy(&initial_parent_pose, 1).expect("parent socket pose");
        let parent_mesh = project_msh_to_static_mesh_in_world_space_with_node_pose_buffer(
            &parent_model,
            identity_transform,
            [1.0; 3],
            &initial_parent_pose,
        )
        .expect("initial parent mesh");
        let child_mesh = project_msh_to_static_mesh_in_world_space_with_node_pose_buffer_and_mount(
            &child_model,
            identity_transform,
            [1.0; 3],
            &initial_child_pose,
            initial_mount,
        )
        .expect("initial mounted child mesh");
        let parent_vertex_count = parent_mesh.vertices.len();
        assert_eq!(parent_vertex_count, 3);
        assert_eq!(child_mesh.vertices.len(), 3);
        let mut vertices = parent_mesh
            .vertices
            .into_iter()
            .chain(child_mesh.vertices)
            .collect::<Vec<_>>();
        let environment_vertex_start =
            u32::try_from(vertices.len()).expect("environment vertex base fits u32");
        let mut environment_vertices = shadow_placeholder_vertices();
        for vertex in &mut environment_vertices {
            vertex.position[0] += 1000.0;
        }
        vertices.extend(environment_vertices);
        let mut indices = vec![0, 1, 2, 3, 4, 5];
        indices.extend(
            quad_indices(1)
                .expect("environment quad indices")
                .into_iter()
                .map(|index| index + environment_vertex_start),
        );
        let draw_range = |first_index, index_count| VulkanStaticDrawRange {
            first_index,
            index_count,
            material_index: 0,
            lightmap_index: u8::MAX,
            batch_flags: 0,
            pipeline_state: world_pipeline_state(
                LegacyBlendMode::Opaque,
                LegacyDepthMode::TestReadOnly,
            ),
            terrain_base_only: false,
            alpha_test_reference: 0,
        };
        let mut mesh = VulkanStaticMesh {
            vertices,
            indices,
            draw_ranges: vec![draw_range(0, 3), draw_range(3, 3), draw_range(6, 6)],
        };
        let control = socket_timeline_control();
        let gate_values = initial_control_gate_values(&control);
        let mut shadow_casters = vec![test_shadow_caster(0, [0.0; 3])];
        shadow_casters[0].triangles = static_mesh_shadow_triangles_in_index_range(&mesh, 0, 6)
            .expect("initial caster triangle geometry");
        let dynamic_shadow_casters = [DynamicShadowCaster {
            caster_index: 0,
            object_index: 0,
            root_transform: identity_transform,
            owner_scale: [1.0; 3],
            initial_sphere: shadow_casters[0].sphere,
            component_draw_range_indices: vec![0, 1],
            component_spheres: vec![
                DynamicShadowSphereSource {
                    component_index: 0,
                    center: [0.0; 3],
                    radius: 1.0,
                    mounted: false,
                },
                DynamicShadowSphereSource {
                    component_index: 1,
                    center: [0.0; 3],
                    radius: 1.0,
                    mounted: true,
                },
            ],
        }];
        let mut instances = vec![vec![
            Some(ControlAnimationInstance {
                control,
                model: parent_model.clone(),
                gate_values,
                state: ControlInstanceState::default(),
                last_sampled_node_times: Vec::new(),
                reported_unsupported_fallback: false,
            }),
            None,
        ]];
        let mut poses = vec![vec![Some(initial_parent_pose), Some(initial_child_pose)]];
        let mut mounts = vec![vec![None, Some(initial_mount)]];
        let geometry = vec![vec![
            Some(DynamicComponentGeometry {
                model: parent_model,
                root_transform: identity_transform,
                owner_scale: [1.0; 3],
                parent_mount: None,
                vertex_start: 0,
                vertex_count: parent_vertex_count,
            }),
            Some(DynamicComponentGeometry {
                model: child_model,
                root_transform: identity_transform,
                owner_scale: [1.0; 3],
                parent_mount: Some((0, 1)),
                vertex_start: parent_vertex_count,
                vertex_count: 3,
            }),
        ]];

        // The fixture's resolved NDP row supplies the native initial value 1.0.
        update_control_animation_pose_buffers(&mut instances, &mut poses, 0)
            .expect("initial active timeline sample");
        let first_root_pose = poses[0][0].as_ref().expect("first root pose").poses[0];
        update_dynamic_component_geometry(&geometry, &poses, &mut mounts, &mut mesh)
            .expect("initial geometry update");
        let range_remap = reorder_draw_ranges(&mut mesh, &[2, 0, 1]).expect("environment reorder");
        let mut dynamic_shadow_casters = dynamic_shadow_casters;
        remap_dynamic_shadow_caster_draw_ranges(&mut dynamic_shadow_casters, &range_remap)
            .expect("dynamic shadow draw-range remap");
        refresh_dynamic_shadow_casters(
            &mut shadow_casters,
            &dynamic_shadow_casters,
            &mesh,
            &poses,
            &mounts,
        )
        .expect("initial caster geometry refresh");
        let encloses_triangles = |sphere: ShadowSphere, triangles: &[ShadowTriangle]| {
            triangles
                .iter()
                .flat_map(|triangle| triangle.positions)
                .all(|point| {
                    let offset = sub3(point, sphere.center);
                    let distance = offset[0].hypot(offset[1]).hypot(offset[2]);
                    distance.is_finite() && distance <= sphere.radius + 1.0e-4
                })
        };
        let first_shadow_sphere = shadow_casters[0].sphere;
        assert!(encloses_triangles(
            first_shadow_sphere,
            &shadow_casters[0].triangles
        ));
        assert_eq!(
            dynamic_shadow_casters[0].component_draw_range_indices,
            [1, 2]
        );
        assert_eq!(shadow_casters[0].triangles.len(), 2);
        assert_eq!(
            shadow_casters[0].triangles[0].positions[0],
            mesh.vertices[0].position
        );
        assert_eq!(
            shadow_casters[0].triangles[1].positions[0],
            mesh.vertices[parent_vertex_count].position
        );
        let first_shadow_triangles = shadow_casters[0].triangles.clone();
        let first_parent_vertex = mesh.vertices[0];
        let first_child_vertex = mesh.vertices[parent_vertex_count];
        let first_mount = mounts[0][1].expect("initial child mount");
        let first_fx_anchor = control_type4_world_from_effect(
            identity_matrix(),
            [1.0; 3],
            identity_transform,
            Some(first_mount),
            control_effect_owner_node_pose(poses[0][1].as_ref(), true, 0)
                .expect("mounted FX owner pose"),
        )
        .expect("initial FX anchor");

        update_control_animation_pose_buffers(&mut instances, &mut poses, 225)
            .expect("later active timeline sample");
        let later_root_pose = poses[0][0].as_ref().expect("later root pose").poses[0];
        assert_ne!(first_root_pose, later_root_pose);
        update_dynamic_component_geometry(&geometry, &poses, &mut mounts, &mut mesh)
            .expect("later geometry update");
        refresh_dynamic_shadow_casters(
            &mut shadow_casters,
            &dynamic_shadow_casters,
            &mesh,
            &poses,
            &mounts,
        )
        .expect("later caster geometry refresh");
        let later_shadow_sphere = shadow_casters[0].sphere;
        let later_shadow_triangles = shadow_casters[0].triangles.clone();
        assert!(encloses_triangles(
            later_shadow_sphere,
            &later_shadow_triangles
        ));
        assert_ne!(first_shadow_triangles, shadow_casters[0].triangles);
        assert_eq!(
            shadow_casters[0].triangles[0].positions[0],
            mesh.vertices[0].position
        );
        let later_parent_vertex = mesh.vertices[0];
        let later_child_vertex = mesh.vertices[parent_vertex_count];
        let later_mount = mounts[0][1].expect("later child mount");
        let later_fx_anchor = control_type4_world_from_effect(
            identity_matrix(),
            [1.0; 3],
            identity_transform,
            Some(later_mount),
            control_effect_owner_node_pose(poses[0][1].as_ref(), true, 0)
                .expect("mounted FX owner pose"),
        )
        .expect("later FX anchor");

        assert_ne!(first_parent_vertex.position, later_parent_vertex.position);
        assert_ne!(first_parent_vertex.normal, later_parent_vertex.normal);
        assert_ne!(first_mount.translation, later_mount.translation);
        assert_eq!(first_child_vertex.position, first_mount.translation);
        assert_eq!(later_child_vertex.position, later_mount.translation);
        assert_ne!(first_fx_anchor[0][3], later_fx_anchor[0][3]);
        assert_ne!(first_fx_anchor[1][3], later_fx_anchor[1][3]);

        update_control_animation_pose_buffers(&mut instances, &mut poses, 225)
            .expect("repeat the same timeline sample");
        update_dynamic_component_geometry(&geometry, &poses, &mut mounts, &mut mesh)
            .expect("repeat the same geometry update");
        refresh_dynamic_shadow_casters(
            &mut shadow_casters,
            &dynamic_shadow_casters,
            &mesh,
            &poses,
            &mounts,
        )
        .expect("repeat the same caster refresh");
        assert_eq!(shadow_casters[0].sphere, later_shadow_sphere);
        assert_eq!(shadow_casters[0].triangles, later_shadow_triangles);

        update_control_animation_pose_buffers(&mut instances, &mut poses, 0)
            .expect("return to the initial timeline sample");
        update_dynamic_component_geometry(&geometry, &poses, &mut mounts, &mut mesh)
            .expect("return to the initial geometry");
        refresh_dynamic_shadow_casters(
            &mut shadow_casters,
            &dynamic_shadow_casters,
            &mesh,
            &poses,
            &mounts,
        )
        .expect("rebuild the initial caster after a later pose");
        assert_eq!(shadow_casters[0].sphere, first_shadow_sphere);
        assert_eq!(shadow_casters[0].triangles, first_shadow_triangles);
    }

    #[test]
    fn visible_exto_parent_refreshes_child_mount_without_parent_geometry() {
        let make_record = |kind, immediate_child_count| fparkan_prototype::UnitComponentRecord {
            archive_raw: [0; 32],
            resource_raw: [0; 32],
            kind,
            parent_or_link: 1,
            description_raw: [0; 32],
            tail0: 0,
            immediate_child_count,
        };
        let records = vec![
            make_record(0, 1),
            make_record(PROTOTYPE_TYPE_EXTO, 1),
            make_record(PROTOTYPE_TYPE_EXTO, 0),
        ];
        let tree = unit_component_tree(&records).expect("valid three-record component tree");
        assert_eq!(tree[2].parent_index, Some(1));
        assert!(tree[1].parent_index.expect("parent has root") < 2);
        assert!(unit_component_is_visible(1, Some(records[1].kind)));

        let identity_transform = LegacyIron3dEulerTransform {
            translation: [0.0; 3],
            orientation_radians: [0.0; 3],
        };
        let mut parent_model = animated_socket_model();
        parent_model.slots.clear();
        parent_model.positions.clear();
        parent_model.normals = None;
        parent_model.uv0 = None;
        parent_model.uv1 = None;
        parent_model.indices.clear();
        parent_model.batches.clear();
        let initial_parent_pose =
            node38_sampled_hierarchy_at_times(&parent_model, &[Some(AnimationTime(0.0)), None])
                .expect("animated parent hierarchy without mesh geometry");
        let parent_mesh = project_msh_to_static_mesh_in_world_space_with_node_pose_buffer(
            &parent_model,
            identity_transform,
            [1.0; 3],
            &initial_parent_pose,
        )
        .expect("parent with no geometry projects successfully");
        assert!(parent_mesh.vertices.is_empty());

        let child_model = static_child_model();
        let child_pose = node38_fallback_hierarchy(&child_model).expect("static child pose");
        let initial_mount =
            node38_pose_from_hierarchy(&initial_parent_pose, 1).expect("visible parent socket");
        let mut mounts = vec![vec![None, None, Some(initial_mount)]];
        let parent_mount = tree[2]
            .parent_index
            .filter(|parent_index| {
                mounts[0][*parent_index].is_some()
                    || unit_component_is_visible(*parent_index, Some(records[*parent_index].kind))
            })
            .map(|parent_index| {
                (
                    parent_index,
                    usize::try_from(records[2].parent_or_link).expect("valid EXTO parent socket"),
                )
            });
        assert_eq!(parent_mount, Some((1, 1)));

        let child_mesh = project_msh_to_static_mesh_in_world_space_with_node_pose_buffer_and_mount(
            &child_model,
            identity_transform,
            [1.0; 3],
            &child_pose,
            initial_mount,
        )
        .expect("initial child mesh");
        let mut mesh = VulkanStaticMesh {
            vertices: child_mesh.vertices,
            indices: child_mesh.indices,
            draw_ranges: Vec::new(),
        };
        let control = socket_timeline_control();
        let controls = vec![None, Some(control.clone()), None];
        assert!(control_tree_chain_has_tag21(2, Some(&tree), &controls));
        let mut instances = vec![vec![
            None,
            Some(ControlAnimationInstance {
                gate_values: initial_control_gate_values(&control),
                control,
                model: parent_model,
                state: ControlInstanceState::default(),
                last_sampled_node_times: Vec::new(),
                reported_unsupported_fallback: false,
            }),
            None,
        ]];
        let mut poses = vec![vec![None, Some(initial_parent_pose), Some(child_pose)]];
        let geometry = vec![vec![
            None,
            None,
            Some(DynamicComponentGeometry {
                model: child_model,
                root_transform: identity_transform,
                owner_scale: [1.0; 3],
                parent_mount,
                vertex_start: 0,
                vertex_count: mesh.vertices.len(),
            }),
        ]];

        update_control_animation_pose_buffers(&mut instances, &mut poses, 0)
            .expect("initial visible parent timeline sample");
        update_dynamic_component_geometry(&geometry, &poses, &mut mounts, &mut mesh)
            .expect("initial child mount refresh");
        let initial_child_vertex = mesh.vertices[0].position;
        let initial_child_mount = mounts[0][2].expect("initial child mount");
        assert_eq!(initial_child_vertex, initial_child_mount.translation);

        update_control_animation_pose_buffers(&mut instances, &mut poses, 225)
            .expect("later visible parent timeline sample");
        update_dynamic_component_geometry(&geometry, &poses, &mut mounts, &mut mesh)
            .expect("child mount refresh without parent geometry descriptor");
        let later_child_mount = mounts[0][2].expect("later child mount");
        assert_ne!(
            initial_child_mount.translation,
            later_child_mount.translation
        );
        assert_eq!(mesh.vertices[0].position, later_child_mount.translation);
    }

    #[test]
    fn dynamic_shadow_sphere_union_keeps_the_containing_input_sphere() {
        let small = ShadowSphere {
            center: [0.0; 3],
            radius: 1.0,
        };
        let large = ShadowSphere {
            center: [1.0, 0.0, 0.0],
            radius: 10.0,
        };

        assert_eq!(
            shadow_sphere_enclosing_current_geometry(small, large, &[])
                .expect("large current native sphere contains baseline"),
            large
        );
        assert_eq!(
            shadow_sphere_enclosing_current_geometry(large, small, &[])
                .expect("large baseline sphere contains current native sphere"),
            large
        );
    }

    fn endpoint_op3_command() -> FxCommand {
        let mut body = vec![0; 0xc4];
        write_effect_u32(&mut body, 0, 2);
        write_effect_f32(&mut body, 0x04, 0.0);
        write_effect_f32(&mut body, 0x08, 1.0);
        write_effect_f32(&mut body, 0x0c, 1.0);
        write_effect_f32(&mut body, 0x10, 0.0);
        write_effect_f32(&mut body, 0x14, 1.0);
        write_effect_f32(&mut body, 0x18, 1.0);
        write_effect_f32(&mut body, 0x1c, 0.0);
        write_effect_f32(&mut body, 0x20, 1.0);
        write_effect_vec3(&mut body, 0x24, [0.0; 3]);
        write_effect_vec3(&mut body, 0x30, [0.0; 3]);
        write_effect_vec3(&mut body, 0x3c, [1.0; 3]);
        write_effect_vec3(&mut body, 0x48, [0.0, 0.0, 1.0]);
        write_effect_vec3(&mut body, 0x54, [0.0, 0.0, 1.0]);
        write_effect_vec3(&mut body, 0x60, [1.0; 3]);
        write_effect_vec3(&mut body, 0x6c, [1.0; 3]);
        write_effect_vec3(&mut body, 0x78, [1.0; 3]);
        body[0x84..0x84 + 11].copy_from_slice(b"effects.rlb");
        let name = b"f_smalllight_y";
        body[0xa4..0xa4 + name.len()].copy_from_slice(name);
        FxCommand {
            word: 3,
            opcode: FxOpcode::Op3,
            native_flag: false,
            raw_body: Arc::from(body),
            resource_refs: Vec::new(),
        }
    }

    fn endpoint_op1_command(effect_type: u32, start: f32, end: f32) -> FxCommand {
        let mut body = vec![0; 132];
        write_effect_u32(&mut body, 0, effect_type);
        write_effect_f32(&mut body, 4, start);
        write_effect_f32(&mut body, 8, end);
        write_effect_vec3(&mut body, 12, [1.0, 0.0, 0.0]);
        write_effect_vec3(&mut body, 24, [3.0, 0.0, 0.0]);
        write_effect_vec3(&mut body, 36, [0.0, 1.0, 0.0]);
        write_effect_vec3(&mut body, 48, [0.0, 1.0, 0.0]);
        for (index, value) in [0.0, 1.0, 0.5, 1.0].into_iter().enumerate() {
            write_effect_f32(&mut body, 60 + index * 4, value);
        }
        for (index, value) in [0.5, 0.0, 1.0, 1.0].into_iter().enumerate() {
            write_effect_f32(&mut body, 76 + index * 4, value);
        }
        write_effect_f32(&mut body, 108, 10.0);
        write_effect_f32(&mut body, 112, 20.0);
        write_effect_f32(&mut body, 116, 1.0);
        write_effect_vec3(&mut body, 120, [1.0, 0.5, 0.25]);
        FxCommand {
            word: 1,
            opcode: FxOpcode::Op1,
            native_flag: false,
            raw_body: Arc::from(body),
            resource_refs: Vec::new(),
        }
    }

    fn endpoint_gener_ball_command(opcode: FxOpcode) -> FxCommand {
        let is_op9 = opcode == FxOpcode::Op9;
        let mut body = vec![0; if is_op9 { 0xcc } else { 0xc8 }];
        write_effect_u32(&mut body, 0, if is_op9 { 2 } else { 0 });
        write_effect_f32(&mut body, 0x04, 0.0);
        write_effect_f32(&mut body, 0x08, 1.0);
        write_effect_f32(&mut body, 0x0c, 1.0);
        write_effect_f32(&mut body, 0x10, 0.0);
        write_effect_f32(&mut body, 0x14, 1.0);
        write_effect_f32(&mut body, 0x18, 1.0);
        write_effect_f32(&mut body, 0x1c, 0.75);
        write_effect_f32(&mut body, 0x20, 1.0);
        write_effect_vec3(&mut body, 0x24, [0.0; 3]);
        write_effect_vec3(&mut body, 0x30, [0.0; 3]);
        write_effect_vec3(&mut body, 0x3c, [1.0; 3]);
        write_effect_vec3(&mut body, 0x48, [0.0, 1.0, 0.0]);
        write_effect_vec3(&mut body, 0x54, [0.0, 1.0, 0.0]);
        write_effect_vec3(&mut body, 0x60, [1.0; 3]);
        write_effect_vec3(&mut body, 0x6c, [1.0; 3]);
        write_effect_vec3(&mut body, 0x78, [1.0; 3]);
        body[0x84..0x84 + 12].copy_from_slice(b"material.lib");
        let name = if is_op9 {
            b"laser_y_hit".as_slice()
        } else {
            b"glow_y"
        };
        body[0xa4..0xa4 + name.len()].copy_from_slice(name);
        if is_op9 {
            write_effect_u32(&mut body, 0xc4, 0);
        } else {
            write_effect_f32(&mut body, 0xc4, 500.0);
        }
        FxCommand {
            word: if is_op9 { 9 } else { 4 },
            opcode,
            native_flag: false,
            raw_body: Arc::from(body),
            resource_refs: Vec::new(),
        }
    }

    fn endpoint_op8_command(pool_count: u32) -> FxCommand {
        let mut body = vec![0; 0xf4];
        write_effect_u32(&mut body, 0x20, pool_count);
        FxCommand {
            word: 8,
            opcode: FxOpcode::Op8,
            native_flag: false,
            raw_body: Arc::from(body),
            resource_refs: Vec::new(),
        }
    }

    fn endpoint_op7_command(
        mode: u32,
        material_phase_factor: f32,
        acceleration: f32,
        pool_count: u32,
        copies_per_group: u32,
    ) -> FxCommand {
        let mut body = vec![0; 0xCC];
        write_effect_u32(&mut body, 0x00, mode);
        write_effect_f32(&mut body, 0x1C, material_phase_factor);
        write_effect_u32(&mut body, 0x20, pool_count);
        write_effect_u32(&mut body, 0x24, copies_per_group);
        write_effect_f32(&mut body, 0x88, acceleration);
        FxCommand {
            word: 7,
            opcode: FxOpcode::Op7,
            native_flag: false,
            raw_body: Arc::from(body),
            resource_refs: Vec::new(),
        }
    }

    fn endpoint_effect_frame(command_index: usize) -> fparkan_fx::fx_visual::EffectQuadFrame {
        fparkan_fx::fx_visual::EffectQuadFrame {
            command_index,
            opcode: FxOpcode::Op7,
            material: fparkan_fx::environment::EffectResource {
                archive: "material.lib".to_owned(),
                name: "smoke_yg".to_owned(),
            },
            vertices: [[0.0; 3]; 4],
            uv: [[0.0; 2]; 4],
            color: [1.0; 4],
            material_phase: 0.25,
            elapsed_seconds: 0.5,
            normalized_time: 0.5,
            active: true,
            native_flag_base: None,
        }
    }

    fn strings(values: &[&str]) -> Vec<String> {
        values.iter().map(|value| (*value).to_string()).collect()
    }

    #[test]
    #[ignore = "requires licensed corpus"]
    fn licensed_corpus_part1_prepares_every_mission() {
        prepare_licensed_corpus("FPARKAN_CORPUS_PART1_ROOT", 29);
    }

    #[test]
    #[ignore = "requires licensed corpus"]
    fn licensed_corpus_part2_prepares_every_mission() {
        prepare_licensed_corpus("FPARKAN_CORPUS_PART2_ROOT", 31);
    }

    fn prepare_licensed_corpus(variable: &str, expected_missions: usize) {
        let root = std::env::var_os(variable)
            .map(PathBuf::from)
            .unwrap_or_else(|| panic!("{variable} is required"));
        assert!(
            root.is_dir(),
            "licensed corpus root is missing: {}",
            root.display()
        );

        let mut missions = Vec::new();
        let mut directories = vec![root.clone()];
        while let Some(directory) = directories.pop() {
            let entries = std::fs::read_dir(&directory)
                .unwrap_or_else(|error| panic!("read {}: {error}", directory.display()));
            for entry in entries {
                let path = entry
                    .unwrap_or_else(|error| {
                        panic!("read entry in {}: {error}", directory.display())
                    })
                    .path();
                if path.is_dir() {
                    directories.push(path);
                } else if path
                    .file_name()
                    .is_some_and(|name| name.eq_ignore_ascii_case("data.tma"))
                {
                    let relative = path
                        .strip_prefix(&root)
                        .expect("mission path is under corpus root")
                        .to_str()
                        .expect("mission path is UTF-8")
                        .replace('\\', "/");
                    missions.push(relative);
                }
            }
        }
        missions.sort();
        assert_eq!(
            missions.len(),
            expected_missions,
            "installed mission count for {variable}"
        );

        let vfs: Arc<dyn fparkan_vfs::Vfs> = Arc::new(DirectoryVfs::new(&root));
        let mut prepared = 0usize;
        let mut environment_missions = 0usize;
        for mission in missions {
            let mut engine = create(EngineServices::new(vfs.clone())).expect("engine");
            let loaded = load_mission_static_preview_roots(
                &mut engine,
                MissionRequest {
                    key: mission.clone(),
                    mode: MissionMode::SingleMission,
                },
                NonZeroUsize::MAX,
            )
            .unwrap_or_else(|error| panic!("prepare runtime mission {mission}: {error}"));
            let assets = loaded_mission_assets(&engine).expect("mission assets");
            let terrain = loaded_terrain(&engine).expect("mission terrain");
            let roots = loaded_mission_object_drafts(&engine).expect("mission object drafts");
            let preview = static_preview_mesh_and_materials(
                assets,
                terrain,
                roots,
                None,
                None,
                None,
                &root,
                &loaded.land_msh_path,
            )
            .unwrap_or_else(|error| panic!("prepare renderer mission {mission}: {error}"));
            assert!(!preview.mesh.vertices.is_empty(), "{mission}: empty mesh");
            assert!(
                !preview.materials.is_empty(),
                "{mission}: empty material set"
            );

            if load_environment(&root, &mission, None, false)
                .unwrap_or_else(|error| panic!("prepare environment mission {mission}: {error}"))
                .is_some()
            {
                environment_missions += 1;
            }

            // `GameAudio::new` resolves and decodes every sample declared by
            // mission.cfg before opening the OS device. A headless CI host is
            // therefore still a useful resource check: only the final device
            // step may be unavailable.
            match audio::GameAudio::new(vfs.clone(), &mission) {
                Ok(mut audio) => audio.shutdown(),
                Err(audio::AudioError::DeviceUnavailable { .. }) => {}
                Err(error) => panic!("prepare audio mission {mission}: {error}"),
            }
            prepared += 1;
        }

        assert_eq!(prepared, expected_missions);
        assert_eq!(environment_missions, expected_missions);
    }

    #[test]
    fn draw_range_reorder_remaps_all_material_animation_bindings() {
        let range = |first_index, material_index| VulkanStaticDrawRange {
            first_index,
            index_count: 3,
            material_index,
            lightmap_index: u8::MAX,
            batch_flags: 0,
            pipeline_state: world_pipeline_state(
                LegacyBlendMode::Opaque,
                LegacyDepthMode::TestReadOnly,
            ),
            terrain_base_only: false,
            alpha_test_reference: 0,
        };
        let mut mesh = VulkanStaticMesh {
            vertices: Vec::new(),
            indices: (0..9).collect(),
            draw_ranges: vec![range(0, 10), range(3, 20), range(6, 30)],
        };
        let empty_binding = || MaterialPhaseBinding {
            document: Mat0Document {
                version: 0,
                animation_block_count: 0,
                phases: Vec::new(),
                prefix: Vec::new(),
                header_opaque: [0; 2],
                animation_blocks: Vec::new(),
            },
            animation_block_index: 0,
            wear_row_start_ms: 0,
            random_state: 0,
            frozen_phase_index: Some(0),
            phase_uv_transforms: Vec::new(),
        };
        let mut bindings = vec![MaterialAnimationBinding {
            initial_phase_index: 0,
            normalized_phase_override: None,
            ambient_fx_material_alpha: false,
            variants: vec![MaterialVariantSet {
                phase_material_indices: vec![10],
                range_indices: vec![0, 2],
                pipeline_category: 0,
            }],
            base: empty_binding(),
            detail: None,
            overlay: None,
            overlay_detail: None,
            stage_textures: None,
        }];

        let remap = reorder_draw_ranges(&mut mesh, &[2, 0, 1]).expect("reorder");
        remap_material_animation_ranges(&mut bindings, &remap).expect("binding remap");

        assert_eq!(
            mesh.indices,
            (6..9).chain(0..3).chain(3..6).collect::<Vec<_>>()
        );
        assert_eq!(mesh.draw_ranges[0].material_index, 30);
        assert_eq!(mesh.draw_ranges[1].material_index, 10);
        assert_eq!(mesh.draw_ranges[2].material_index, 20);
        assert_eq!(bindings[0].variants[0].range_indices, vec![1, 0]);
    }

    #[test]
    fn native_world_transparency_uses_sampled_alpha_and_native_batch_flags() {
        let range = |blend, batch_flags| VulkanStaticDrawRange {
            first_index: 0,
            index_count: 3,
            material_index: 0,
            lightmap_index: u8::MAX,
            batch_flags,
            pipeline_state: world_pipeline_state(blend, LegacyDepthMode::TestReadOnly),
            terrain_base_only: false,
            alpha_test_reference: 0,
        };

        // Transparency is driven by the native predicate. The pipeline blend
        // enum is an independent rendering detail and does not qualify an
        // opaque range on its own.
        assert!(!native_world_transparent(
            &range(LegacyBlendMode::SourceAlpha, 0),
            1.0
        ));
        assert!(native_world_transparent(
            &range(LegacyBlendMode::Opaque, 0),
            0.999
        ));
        assert!(native_world_transparent(
            &range(LegacyBlendMode::Opaque, 0x100),
            1.0
        ));
        assert!(native_world_transparent(
            &range(LegacyBlendMode::Opaque, 0x8),
            1.0
        ));
    }

    #[test]
    fn native_cpu_shaded_msh_alpha_override_uses_only_the_constant_batch_rule() {
        assert_eq!(native_msh_diffuse_alpha_override(0x0148, false), Some(0.0));
        assert_eq!(native_msh_diffuse_alpha_override(0x0108, false), None);
        assert_eq!(native_msh_diffuse_alpha_override(0x0118, false), None);
        assert_eq!(native_msh_diffuse_alpha_override(0x0058, false), None);
        assert_eq!(native_msh_diffuse_alpha_override(0x0148, true), None);
        assert_eq!(native_msh_diffuse_alpha_override(0x0058, true), None);
        assert_eq!(native_msh_diffuse_alpha_override(0x0040, false), None);
    }

    #[test]
    fn material_animation_selects_pipeline_category_with_active_phase() {
        let variant = MaterialVariantSet {
            phase_material_indices: vec![10, 11],
            range_indices: vec![3],
            pipeline_category: 1,
        };
        let category_for = |material_index| match material_index {
            10 => Some(1),
            11 => Some(2),
            _ => None,
        };

        assert_eq!(
            selected_material_phase(&variant, 0, category_for),
            Ok((10, 1))
        );
        assert_eq!(
            selected_material_phase(&variant, 1, category_for),
            Ok((11, 2))
        );
        assert!(selected_material_phase(&variant, 2, category_for).is_err());
    }

    #[test]
    fn native_shadow_kind_mapping_keeps_sun_eligibility_separate_from_caster_defaults() {
        assert_eq!(native_shadow_kind(Some(PROTOTYPE_TYPE_FORT)), Some(3));
        assert_eq!(native_shadow_kind(Some(PROTOTYPE_TYPE_BTLU)), Some(4));
        assert_eq!(native_shadow_kind(Some(PROTOTYPE_TYPE_STAT)), Some(10));
        assert!(!native_shadow_caster_enabled(3));
        assert!(native_shadow_caster_enabled(4));
        assert!(!native_shadow_caster_enabled(10));
        assert!(native_sun_object_kind_eligible(Some(PROTOTYPE_TYPE_FORT)));
        assert!(native_sun_object_kind_eligible(Some(PROTOTYPE_TYPE_BTLU)));
        assert!(native_sun_object_kind_eligible(Some(PROTOTYPE_TYPE_STAT)));
        assert!(!native_sun_object_kind_eligible(Some(PROTOTYPE_TYPE_EXTO)));
        assert!(!native_sun_object_kind_eligible(None));
    }

    fn test_shadow_caster(id: u32, center: [f32; 3]) -> ShadowCaster {
        ShadowCaster {
            id,
            world_axes: [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]],
            sphere: ShadowSphere {
                center,
                radius: 0.0,
            },
            native_kind: 4,
            triangles: Vec::new(),
        }
    }

    #[test]
    fn shadow_frustum_filters_before_the_native_twenty_caster_budget() {
        let casters = [
            test_shadow_caster(1, [202.0, 0.0, 0.0]),
            test_shadow_caster(2, [0.0, 0.0, 0.0]),
        ];
        let visible =
            native_visible_shadow_casters(&casters, VulkanStaticCamera::default().clip_from_world);
        assert_eq!(
            visible.iter().map(|caster| caster.id).collect::<Vec<_>>(),
            [2]
        );
    }

    #[test]
    fn shadow_frustum_keeps_the_native_hundred_unit_sphere_margin() {
        let matrix = VulkanStaticCamera::default().clip_from_world;
        assert!(native_shadow_caster_visible(
            &test_shadow_caster(1, [100.99, 0.0, 0.0]),
            matrix
        ));
        assert!(!native_shadow_caster_visible(
            &test_shadow_caster(2, [101.0, 0.0, 0.0]),
            matrix
        ));
    }

    #[test]
    fn projected_shadow_alone_uses_decal_depth_bias() {
        let shadow = projected_shadow_pipeline_state();
        assert_eq!(shadow.blend, LegacyBlendMode::SourceAlpha);
        assert_eq!(shadow.depth, LegacyDepthMode::TestReadOnly);
        assert_eq!(shadow.depth_bias, LegacyDepthBias::ProjectedDecal);
        assert_eq!(
            world_pipeline_state(LegacyBlendMode::Opaque, LegacyDepthMode::TestWrite).depth_bias,
            LegacyDepthBias::Disabled
        );
    }

    #[test]
    fn shadow_atlas_texture_equality_includes_pixels_and_mip_layout() {
        let uploaded = shadow_atlas_texture();
        assert_eq!(shadow_atlas_texture(), uploaded);

        let mut changed_rgba = uploaded.clone();
        changed_rgba.rgba8[0] ^= 1;
        assert_ne!(changed_rgba, uploaded);

        let mut changed_mip_pixels = uploaded.clone();
        changed_mip_pixels.mip_levels[0].rgba8[0] ^= 1;
        assert_ne!(changed_mip_pixels, uploaded);

        let mut changed_mip = uploaded.clone();
        changed_mip.mip_levels[0].width -= 1;
        assert_ne!(changed_mip, uploaded);
    }

    #[test]
    fn mounted_shadow_bounds_ignore_child_translation_and_scale_aggregate_once() {
        let parent = VulkanNodePose {
            translation: [10.0, 20.0, 30.0],
            rotation: [0.0, 0.0, 0.0, 1.0],
        };
        let node1 = VulkanNodePose {
            // Native bounds replace this translation with the accumulated
            // parent translation while retaining node 1's rotation.
            translation: [99.0, -77.0, 42.0],
            rotation: [0.0, 0.0, (0.5_f32).sqrt(), (0.5_f32).sqrt()],
        };
        let first = mounted_shadow_sphere([2.0, 0.0, 0.0], 2.0, Some(parent), Some(node1))
            .expect("finite mounted sphere");
        assert!((first.center[0] - 10.0).abs() < 1.0e-5);
        assert!((first.center[1] - 22.0).abs() < 1.0e-5);
        assert!((first.center[2] - 30.0).abs() < 1.0e-5);

        let second = ShadowComponentSphere {
            center: [12.0, 22.0, 30.0],
            radius: 1.0,
        };
        let caster = aggregate_shadow_caster(
            7,
            4,
            LegacyIron3dEulerTransform {
                translation: [1.0, 2.0, 3.0],
                orientation_radians: [0.0; 3],
            },
            [2.0, 3.0, 4.0],
            vec![shadow_triangle(
                [[0.0, 0.0, 0.0], [1.0, 0.0, 0.0], [0.0, 1.0, 0.0]],
                0,
            )],
            &[first, second],
        )
        .expect("aggregate caster");
        let nearly_equal = |left: f32, right: f32| assert!((left - right).abs() < 1.0e-4);
        nearly_equal(caster.sphere.center[0], 22.333_334);
        nearly_equal(caster.sphere.center[1], 68.0);
        nearly_equal(caster.sphere.center[2], 123.0);
        nearly_equal(caster.sphere.radius, 10.666_667);
    }

    #[test]
    fn internal_components_do_not_enter_msh_socket_mount_path() {
        assert!(unit_component_is_visible(0, None));
        assert!(!unit_component_is_visible(1, None));
        assert!(unit_component_is_visible(1, Some(PROTOTYPE_TYPE_EXTO)));
    }

    #[test]
    fn parses_required_args() {
        assert_eq!(
            Args::parse(&strings(&[
                "--root",
                "testdata/IS",
                "--mission",
                "MISSIONS/Autodemo.00/data.tma",
                "--frames",
                "3",
            ])),
            Ok(Args {
                root: PathBuf::from("testdata/IS"),
                mission: "MISSIONS/Autodemo.00/data.tma".to_string(),
                frames: 3,
                atmosphere_seconds: None,
                control_clock_ms: None,
                validation: false,
                readback_out: None,
                readback_sequence_out: None,
                preview_roots: NonZeroUsize::MAX,
                legacy_camera_capture: None,
                static_animation_frame: None,
                static_material_phase: None,
            })
        );
    }

    #[test]
    fn defaults_to_interactive_frame_loop() {
        let parsed = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
        ]))
        .expect("default interactive arguments");
        assert_eq!(parsed.frames, 0);
        assert_eq!(parsed.preview_roots, NonZeroUsize::MAX);
        assert_eq!(parsed.static_animation_frame, None);
        assert_eq!(parsed.control_clock_ms, None);
    }

    #[test]
    fn control_clock_replays_one_shared_clock_from_zero_to_target() {
        assert_eq!(control_clock_ms_for_frame(500, 0, 101), 0);
        assert_eq!(control_clock_ms_for_frame(500, 50, 101), 250);
        assert_eq!(control_clock_ms_for_frame(500, 100, 101), 500);
        assert_eq!(control_clock_ms_for_frame(500, 1000, 101), 500);
        assert_eq!(control_clock_ms_for_frame(500, 0, 1), 500);
        assert_eq!(control_clock_mode_label(Some(0)), "fixed-0ms");
        assert_eq!(control_clock_mode_label(Some(500)), "ramp-0-to-500ms");
        assert_eq!(control_clock_mode_label(None), "realtime");
    }

    fn clock_test_app(
        control_clock_target_ms: Option<u32>,
    ) -> (StaticVulkanApp, ControlEffectInstanceKey) {
        let phase = |additive_red| MaterialPhase {
            parameters: [
                additive_red,
                0,
                0,
                100,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
            ],
            texture_raw: [0; 16],
        };
        let document = Mat0Document {
            version: 0,
            animation_block_count: 1,
            phases: vec![phase(0), phase(255)],
            prefix: Vec::new(),
            header_opaque: [0; 2],
            animation_blocks: vec![MaterialAnimationBlock {
                header_raw: 0,
                keys: vec![
                    MaterialKey {
                        k0: 0,
                        k1: 500,
                        k2: 0,
                    },
                    MaterialKey {
                        k0: 1,
                        k1: 1000,
                        k2: 0,
                    },
                ],
                bytes: Vec::new(),
            }],
        };
        let material_animation = MaterialAnimationBinding {
            initial_phase_index: 0,
            normalized_phase_override: None,
            ambient_fx_material_alpha: false,
            variants: vec![MaterialVariantSet {
                phase_material_indices: vec![0, 1],
                range_indices: vec![0],
                pipeline_category: 0,
            }],
            base: MaterialPhaseBinding {
                document,
                animation_block_index: 0,
                wear_row_start_ms: 0,
                random_state: 0,
                frozen_phase_index: None,
                phase_uv_transforms: vec![[0.0, 0.0, 1.0, 1.0]; 2],
            },
            detail: None,
            overlay: None,
            overlay_detail: None,
            stage_textures: None,
        };
        let mut materials = Vec::new();
        append_environment_gradient_material(&mut materials)
            .expect("first animated material variant");
        append_environment_gradient_material(&mut materials)
            .expect("second animated material variant");

        let key = ControlEffectInstanceKey {
            object_index: 0,
            component_index: 0,
            table_index: 0,
            row_index: 0,
        };
        let control_slot = ControlPointLightSlot {
            time_mode: 1,
            header_flags: 9,
            random_instance_key: key,
            random_seed: 0x1234_5678,
            phase_jitter: 0.25,
            random_shift: [2.0, 3.0, 4.0],
            duration_seconds: 1.0,
            owner_object_index: 0,
            owner_component_index: 0,
            owner_node_index: 0,
            owner_component_is_mounted: false,
            root_transform: LegacyIron3dEulerTransform {
                translation: [10.0, 20.0, 30.0],
                orientation_radians: [0.0; 3],
            },
            owner_scale: [1.0; 3],
            mount_pose: None,
            local_from_effect: [
                [1.0, 0.0, 0.0, 1.0],
                [0.0, 1.0, 0.0, 2.0],
                [0.0, 0.0, 1.0, 3.0],
                [0.0, 0.0, 0.0, 1.0],
            ],
            world_from_effect: [[0.0; 4]; 4],
            command_index: 0,
            command: endpoint_op1_command(6, 0.5, 1.0),
        };

        let sky_materials = SkyMaterials::default();
        let sky =
            SkySystem::new(Default::default(), sky_materials.clone()).expect("test sky topology");
        let environment = DynamicEnvironment {
            schedule: TypedAtmosphere {
                marker: 0,
                version: 0,
                tracks: Vec::new(),
                trailer: Default::default(),
            },
            sky,
            environment: EnvironmentSystem::new(0x4650_4152_4B41_4E),
            materials: sky_materials,
            material_assets: HashMap::new(),
            schedule_offset_seconds: 0.0,
            time_seconds: 0.0,
            fixed_schedule_seconds: None,
            fixed_phase_reported: false,
        };

        let mut land = fparkan_terrain_format::LandMeshDocument {
            streams: Vec::new(),
            nodes_raw: Vec::new(),
            slots: fparkan_terrain_format::TerrainSlotTable {
                header_raw: Vec::new(),
                slots_raw: Vec::new(),
            },
            positions: vec![[0.0, 0.0, 0.0], [10.0, 0.0, 0.0], [0.0, 10.0, 0.0]],
            normals: Vec::new(),
            uv0: Vec::new(),
            accelerator: Vec::new(),
            aux14: Vec::new(),
            aux18: Vec::new(),
            faces: vec![fparkan_terrain_format::TerrainFace28 {
                flags: FullSurfaceMask(1),
                material_tag: 0,
                aux_tag: 0,
                vertices: [0, 1, 2],
                neighbors: [None, None, None],
                tail_raw: [0; 8],
                raw: [0; 28],
            }],
        };
        set_test_terrain_lod_slots(&mut land, &[[0, u16::MAX]], &[[0, 1]]);
        let terrain =
            Arc::new(TerrainWorld::from_land_msh(&land).expect("clock test LOD0 terrain"));
        let free_camera = FreeFlightCamera {
            position: [2.0, 2.0, 5.0],
            yaw: 0.25,
            pitch: -0.1,
            horizontal_fov: 1.3,
            near_plane: 0.5,
            far_plane: 700.0,
            move_speed: 4.0,
            ground_clearance: 0.0,
        };
        let view_camera = free_camera.preview_frame(16.0 / 9.0);
        let preview = StaticPreviewScene {
            mesh: VulkanStaticMesh {
                vertices: [[0.0, 0.0, 0.0], [1.0, 0.0, 0.0], [0.0, 1.0, 0.0]]
                    .into_iter()
                    .map(|position| VulkanStaticVertex {
                        position,
                        color: [1.0; 3],
                        normal: [0.0, 0.0, 1.0],
                        uv: [0.0; 2],
                        detail_uv: [0.0; 2],
                        overlay_alpha: 0.0,
                    })
                    .collect(),
                indices: vec![0, 1, 2],
                draw_ranges: vec![VulkanStaticDrawRange {
                    first_index: 0,
                    index_count: 3,
                    material_index: 0,
                    lightmap_index: u8::MAX,
                    batch_flags: 0,
                    terrain_base_only: false,
                    pipeline_state: world_pipeline_state(
                        LegacyBlendMode::Opaque,
                        LegacyDepthMode::TestReadOnly,
                    ),
                    alpha_test_reference: 0,
                }],
            },
            native_handedness_by_range: HashMap::new(),
            type16_present_ranges: HashSet::new(),
            materials,
            material_animations: vec![material_animation],
            ambient_effect_slots: Vec::new(),
            control_point_light_slots: vec![control_slot],
            component_pose_buffers: vec![vec![None]],
            component_mount_poses: vec![vec![None]],
            dynamic_component_geometry: Vec::new(),
            building_collision_bindings: Vec::new(),
            control_animation_instances: Vec::new(),
            dynamic_shadow_casters: Vec::new(),
            sun_occlusion_range_indices: Vec::new(),
            shadow_casters: Vec::new(),
            shadow_receivers: Vec::new(),
            shadow_material_index: 0,
            terrain: terrain.clone(),
            camera: view_camera.vulkan_camera(),
            view_camera,
            captured_viewport: None,
            free_camera: Some(free_camera),
            camera_mode: "test",
            mesh_components: 0,
            terrain_components: 0,
        };
        let app = StaticVulkanApp::new(
            preview,
            Some(environment),
            None,
            EnvironmentGpuRange {
                range_index: 1,
                vertex_start: 3,
                vertex_capacity: 0,
                material_index: 0,
            },
            3,
            3,
            None,
            2,
            "clock-test",
            1,
            None,
            None,
            false,
            control_clock_target_ms,
            StartupTimings::default(),
        );
        (app, key)
    }

    fn control_random_snapshot(
        state: &ControlEffectRandomState,
    ) -> (
        u32,
        u32,
        ControlEffectRandomSample,
        Option<SceneSampleId>,
        Option<u32>,
    ) {
        (
            state.phase_and_z_rng.state,
            state.xy_rng.state,
            state.sample,
            state.last_update_id,
            state.last_update_clock_ms,
        )
    }

    #[test]
    fn live_clock_samples_have_increasing_ids_and_monotonic_time() {
        let (mut app, _) = clock_test_app(None);
        let first = app.sample_frame_clock();
        let second = app.sample_frame_clock();
        assert_eq!(first.id, SceneSampleId::Live(0));
        assert_eq!(second.id, SceneSampleId::Live(1));
        assert!(second.time_ms >= first.time_ms);
        assert!(second.delta_seconds >= 0.0);
    }

    #[test]
    fn zero_extent_resume_does_not_add_minimized_time_to_live_clock() {
        let (mut app, _) = clock_test_app(None);
        let started = Instant::now();
        app.simulation_last_tick = started;
        app.pause_live_clock_at(started);
        assert!(app.live_clock_paused_for_zero_extent);

        let restored = started + Duration::from_secs(600);
        app.resume_live_clock_at(restored);
        assert!(!app.live_clock_paused_for_zero_extent);
        assert_eq!(app.simulation_last_tick, restored);

        let resumed = app.sample_live_frame_clock_at(restored + Duration::from_millis(16));
        assert_eq!(resumed.id, SceneSampleId::Live(0));
        assert_eq!(resumed.time_ms, 16);
        assert!((resumed.delta_seconds - 0.016).abs() < 1.0e-6);
        assert_eq!(app.simulation_elapsed, Duration::from_millis(16));
    }

    #[test]
    fn live_cpu_updates_sample_materials_effect_rng_and_environment_without_renderer() {
        let (mut app, key) = clock_test_app(None);
        app.render_scene_update()
            .expect("an early redraw without a packet is a no-op");
        assert!(app.pending_scene_update.is_none());
        assert_eq!(app.frames_presented, 0);
        assert_eq!(app.simulation_update_generation, 0);

        let mut first = app.sample_frame_clock();
        assert_eq!(first.id, SceneSampleId::Live(0));
        first.time_ms = 0;
        first.delta_seconds = 0.1;
        app.prepare_scene_update(first, [1280.0, 720.0])
            .expect("prepare a live CPU frame without a renderer");
        assert!(app.renderer.is_none());
        let first_frame = app.pending_scene_update.as_ref().expect("sampled frame");
        assert_eq!(
            first_frame.material_update.active_materials[&0].phase_index,
            0
        );
        assert!(!first_frame
            .environment
            .as_ref()
            .unwrap()
            .sky_mesh
            .vertices
            .is_empty());
        let first_random = control_random_snapshot(&app.control_effect_random_states[&key]);
        assert_eq!(first_random.3, Some(SceneSampleId::Live(0)));
        assert_ne!(first_random.0, 0);
        assert_ne!(first_random.1, 0);
        let first_environment_time = app.environment.as_ref().unwrap().time_seconds;
        assert!(first_environment_time > 0.0);
        let first_vertices = app.mesh.vertices.clone();

        for _ in 0..2 {
            app.render_scene_update()
                .expect("renderer-free redraw does not sample simulation state");
        }
        assert_eq!(
            control_random_snapshot(&app.control_effect_random_states[&key]),
            first_random
        );
        assert_eq!(
            app.environment.as_ref().unwrap().time_seconds,
            first_environment_time
        );
        assert_eq!(app.mesh.vertices, first_vertices);
        assert_eq!(app.simulation_update_generation, 1);

        let mut next = app.sample_frame_clock();
        assert_eq!(next.id, SceneSampleId::Live(1));
        next.time_ms = 500;
        next.delta_seconds = 0.5;
        app.prepare_scene_update(next, [1280.0, 720.0])
            .expect("replace the latest live packet");
        assert_eq!(app.simulation_update_generation, 2);
        assert_eq!(
            app.pending_scene_update.as_ref().unwrap().clock.id,
            SceneSampleId::Live(1)
        );
        assert_ne!(
            control_random_snapshot(&app.control_effect_random_states[&key]),
            first_random
        );
        assert!(app.environment.as_ref().unwrap().time_seconds > first_environment_time);
        assert_eq!(
            app.pending_scene_update
                .as_ref()
                .unwrap()
                .material_update
                .active_materials[&0]
                .phase_index,
            1
        );
        assert_eq!(
            app.pending_scene_update.as_ref().unwrap().clock.time_ms,
            500
        );
    }

    #[test]
    fn live_pending_resize_reuses_225ms_packet_across_zero_extent_pause() {
        let (mut app, key) = clock_test_app(None);
        let started = Instant::now();
        app.simulation_last_tick = started;
        app.pressed_keys.insert(KeyCode::KeyE);

        let first = app.sample_live_frame_clock_at(started + Duration::from_millis(225));
        assert_eq!(first.id, SceneSampleId::Live(0));
        assert_eq!(first.time_ms, 225);
        assert!((first.delta_seconds - 0.225).abs() < 1.0e-6);
        app.prepare_scene_update(first, [1280.0, 720.0])
            .expect("sample one 225 ms live packet");
        let first_frame = app.pending_scene_update.as_ref().unwrap();
        let first_camera = first_frame.camera;
        let expected_resized_camera = app
            .free_camera
            .expect("free-flight input controller")
            .preview_frame(4.0 / 3.0);
        let first_effect_updates = first_frame.effect_updates.clone();
        let first_material_phase = first_frame.material_update.active_materials[&0].phase_index;
        let weather = WeatherInput {
            rain: WeatherState::new(true, 0.03, [0.7, 0.8, 1.0, 0.6]),
            snow: WeatherState::new(true, 0.03, [0.9, 0.95, 1.0, 0.8]),
            ..WeatherInput::clear()
        };
        let mut weather_system = EnvironmentSystem::new(0xC1_225);
        let first_environment_frame = weather_system.update(
            0.225,
            weather,
            environment_camera_for_preview(&first_camera, 16.0 / 9.0, [1280.0, 720.0]),
        );
        let mut precipitation_counts = [0usize; 2];
        for primitive in &first_environment_frame.primitives {
            if let EnvironmentPrimitive::Particle { kind, .. } = primitive {
                let slot = match kind {
                    PrecipitationKind::Rain => 0,
                    PrecipitationKind::Snow => 1,
                };
                precipitation_counts[slot] += 1;
            }
        }
        assert!(precipitation_counts.iter().all(|count| *count >= 17));
        app.pending_scene_update
            .as_mut()
            .unwrap()
            .environment
            .as_mut()
            .unwrap()
            .environment_frame = first_environment_frame.clone();
        let first_random = control_random_snapshot(&app.control_effect_random_states[&key]);
        let first_environment_time = app.environment.as_ref().unwrap().time_seconds;
        let first_environment_system_time =
            app.environment.as_ref().unwrap().environment.time_seconds();
        let first_vertices = app.mesh.vertices.clone();
        assert!((first_camera.position[2] - 5.4).abs() < 1.0e-5);
        assert_eq!(app.simulation_elapsed, Duration::from_millis(225));
        assert_eq!(app.simulation_update_generation, 1);

        app.pause_live_clock_at(started + Duration::from_millis(250));
        let restored = started + Duration::from_secs(10);
        app.resume_live_clock_at(restored);
        app.free_camera.as_mut().unwrap().look_delta(64.0, -24.0);
        let controller_after_input = app.free_camera.unwrap();
        let retry = app.pending_or_sample_frame_clock();
        assert_eq!(retry, first);
        assert_eq!(app.simulation_update_generation, 1);
        assert_eq!(app.simulation_elapsed, Duration::from_millis(225));
        assert_eq!(app.simulation_last_tick, restored);

        app.prepare_scene_update(retry, [1024.0, 768.0])
            .expect("refresh only the pending packet's viewport");
        let retry_frame = app.pending_scene_update.as_ref().unwrap();
        assert_eq!(retry_frame.clock, first);
        assert_eq!(retry_frame.viewport, [1024.0, 768.0]);
        assert_eq!(retry_frame.aspect, 4.0 / 3.0);
        assert_eq!(retry_frame.camera.position, first_camera.position);
        assert_eq!(retry_frame.camera.forward, first_camera.forward);
        assert_eq!(retry_frame.camera.right, first_camera.right);
        assert_eq!(retry_frame.camera.up, first_camera.up);
        assert_eq!(
            retry_frame.camera.position,
            expected_resized_camera.position
        );
        assert_eq!(retry_frame.camera.forward, expected_resized_camera.forward);
        assert_eq!(retry_frame.camera.right, expected_resized_camera.right);
        assert_eq!(retry_frame.camera.up, expected_resized_camera.up);
        assert!(
            (retry_frame.camera.vertical_fov - expected_resized_camera.vertical_fov).abs() < 1.0e-6
        );
        assert!(retry_frame
            .camera
            .clip_from_world
            .iter()
            .zip(expected_resized_camera.clip_from_world)
            .all(|(actual, expected)| (actual - expected).abs() < 1.0e-5));
        assert_ne!(
            retry_frame.camera.clip_from_world,
            first_camera.clip_from_world
        );
        assert_eq!(app.free_camera, Some(controller_after_input));
        assert_eq!(retry_frame.effect_updates, first_effect_updates);
        assert_eq!(
            retry_frame.material_update.active_materials[&0].phase_index,
            first_material_phase
        );
        let retry_environment_frame = &retry_frame.environment.as_ref().unwrap().environment_frame;
        assert_eq!(
            retry_environment_frame.point_lights,
            first_environment_frame.point_lights
        );
        assert_eq!(
            retry_environment_frame.sounds,
            first_environment_frame.sounds
        );
        let mut reprojected_counts = [0usize; 2];
        for (sampled, refreshed) in first_environment_frame
            .primitives
            .iter()
            .zip(&retry_environment_frame.primitives)
        {
            let (
                EnvironmentPrimitive::Particle {
                    kind: sampled_kind,
                    position: sampled_position,
                    velocity: sampled_velocity,
                    size: sampled_size,
                    screen: sampled_screen,
                    ..
                },
                EnvironmentPrimitive::Particle {
                    kind,
                    position,
                    velocity,
                    size,
                    screen,
                    ..
                },
            ) = (sampled, refreshed)
            else {
                panic!("rain and snow fixture contains only precipitation particles");
            };
            assert_eq!(kind, sampled_kind);
            assert_eq!(position, sampled_position);
            assert_eq!(velocity, sampled_velocity);
            assert_ne!(screen, sampled_screen);
            let slot = match kind {
                PrecipitationKind::Rain => 0,
                PrecipitationKind::Snow => 1,
            };
            reprojected_counts[slot] += 1;
            assert_ne!(size, sampled_size);
        }
        assert!(reprojected_counts.iter().all(|count| *count >= 17));
        assert_eq!(
            control_random_snapshot(&app.control_effect_random_states[&key]),
            first_random
        );
        assert_eq!(
            app.environment.as_ref().unwrap().time_seconds,
            first_environment_time
        );
        assert_eq!(
            app.environment.as_ref().unwrap().environment.time_seconds(),
            first_environment_system_time
        );
        assert_eq!(app.mesh.vertices, first_vertices);

        assert_eq!(app.record_presented_scene_frame(), 0);
        let next = app.sample_live_frame_clock_at(restored + Duration::from_millis(16));
        assert_eq!(next.id, SceneSampleId::Live(1));
        assert_eq!(next.time_ms, 241);
        assert!((next.delta_seconds - 0.016).abs() < 1.0e-6);
        assert_eq!(app.simulation_elapsed, Duration::from_millis(241));
        app.prepare_scene_update(next, [1024.0, 768.0])
            .expect("the next sample adopts mouse input accumulated during retry");
        let next_camera = app.pending_scene_update.as_ref().unwrap().camera;
        assert_ne!(next_camera.forward, first_camera.forward);
        assert_eq!(next_camera.forward, controller_after_input.forward());
    }

    #[test]
    fn replay_retries_keep_one_packet_until_presented_then_advance_with_new_viewport() {
        let (mut app, key) = clock_test_app(Some(500));
        app.render_scene_update()
            .expect("redraw without a pending packet does nothing");
        assert_eq!(app.simulation_update_generation, 0);

        let first = app.sample_frame_clock();
        assert_eq!(
            first,
            FrameClockSample {
                id: SceneSampleId::Replay(0),
                time_ms: 0,
                delta_seconds: 0.0,
            }
        );
        app.prepare_scene_update(first, [1280.0, 720.0])
            .expect("prepare the first replay frame");
        let first_frame = app.pending_scene_update.as_ref().unwrap();
        let first_camera = first_frame.camera;
        let first_viewport = first_frame.viewport;
        let first_aspect = first_frame.aspect;
        let first_effect_updates = first_frame.effect_updates.clone();
        let first_environment_mesh = first_frame.environment.as_ref().unwrap().sky_mesh.clone();
        let first_environment_frame = first_frame
            .environment
            .as_ref()
            .unwrap()
            .environment_frame
            .clone();
        let first_material_phase = first_frame.material_update.active_materials[&0].phase_index;
        let first_environment_time = app.environment.as_ref().unwrap().time_seconds;
        let first_random = control_random_snapshot(&app.control_effect_random_states[&key]);
        let first_vertices = app.mesh.vertices.clone();
        assert_eq!(first_material_phase, 0);
        assert_eq!(first_random.3, Some(SceneSampleId::Replay(0)));
        assert_eq!(first_random.4, Some(0));
        assert!(!first_environment_mesh.vertices.is_empty());

        for _ in 0..2 {
            app.render_scene_update()
                .expect("renderer-free replay redraw is a retry");
            let retry = app.sample_frame_clock();
            assert_eq!(retry.id, SceneSampleId::Replay(0));
            app.prepare_scene_update(retry, [1024.0, 768.0])
                .expect("a resize retry reuses the current replay packet");
        }
        let retry_frame = app.pending_scene_update.as_ref().unwrap();
        assert_eq!(retry_frame.camera.position, first_camera.position);
        assert_eq!(retry_frame.camera.forward, first_camera.forward);
        assert_eq!(retry_frame.camera.up, first_camera.up);
        assert_eq!(retry_frame.viewport, [1024.0, 768.0]);
        assert_eq!(retry_frame.aspect, 4.0 / 3.0);
        assert_ne!(
            retry_frame.camera.clip_from_world,
            first_camera.clip_from_world
        );
        assert_ne!(retry_frame.viewport, first_viewport);
        assert_ne!(retry_frame.aspect, first_aspect);
        assert_eq!(retry_frame.effect_updates, first_effect_updates);
        assert_eq!(
            retry_frame.environment.as_ref().unwrap().sky_mesh,
            first_environment_mesh
        );
        assert_eq!(
            retry_frame.environment.as_ref().unwrap().environment_frame,
            first_environment_frame
        );
        assert_eq!(
            retry_frame.material_update.active_materials[&0].phase_index,
            0
        );
        assert_eq!(
            control_random_snapshot(&app.control_effect_random_states[&key]),
            first_random
        );
        assert_eq!(
            app.environment.as_ref().unwrap().time_seconds,
            first_environment_time
        );
        assert_eq!(app.mesh.vertices, first_vertices);
        assert_eq!(app.frames_presented, 0);

        assert_eq!(app.record_presented_scene_frame(), 0);
        assert_eq!(app.frames_presented, 1);
        assert!(app.pending_scene_update.is_none());
        let next = app.sample_frame_clock();
        assert_eq!(next.id, SceneSampleId::Replay(1));
        assert_eq!(next.time_ms, 500);
        assert_eq!(next.delta_seconds, 0.5);
        app.prepare_scene_update(next, [1024.0, 768.0])
            .expect("the next presented replay frame samples the resized view");
        let next_frame = app.pending_scene_update.as_ref().unwrap();
        assert_eq!(next_frame.viewport, [1024.0, 768.0]);
        assert_eq!(next_frame.aspect, 4.0 / 3.0);
        assert_ne!(
            next_frame.camera.clip_from_world,
            first_camera.clip_from_world
        );
        assert_eq!(
            next_frame.material_update.active_materials[&0].phase_index,
            1
        );
        assert!(
            (app.environment.as_ref().unwrap().time_seconds - first_environment_time - 0.5).abs()
                < 1.0e-6
        );
        let next_random = control_random_snapshot(&app.control_effect_random_states[&key]);
        assert_eq!(next_random.3, Some(SceneSampleId::Replay(1)));
        assert_eq!(next_random.4, Some(500));
        assert_ne!(next_random, first_random);
        let next_camera = next_frame.camera;
        let next_environment_mesh = next_frame.environment.as_ref().unwrap().sky_mesh.clone();
        let next_environment_frame = next_frame
            .environment
            .as_ref()
            .unwrap()
            .environment_frame
            .clone();

        app.render_scene_update()
            .expect("renderer-free draw does not advance the replay packet");
        let repeated = app.sample_frame_clock();
        assert_eq!(repeated.id, SceneSampleId::Replay(1));
        app.prepare_scene_update(repeated, [800.0, 600.0])
            .expect("duplicate replay frame is idempotent");
        let repeated_frame = app.pending_scene_update.as_ref().unwrap();
        assert_eq!(repeated_frame.viewport, [800.0, 600.0]);
        assert_eq!(repeated_frame.aspect, 4.0 / 3.0);
        assert_eq!(repeated_frame.camera, next_camera);
        assert_eq!(
            repeated_frame.environment.as_ref().unwrap().sky_mesh,
            next_environment_mesh
        );
        assert_eq!(
            repeated_frame
                .environment
                .as_ref()
                .unwrap()
                .environment_frame,
            next_environment_frame
        );
        assert_eq!(
            control_random_snapshot(&app.control_effect_random_states[&key]),
            next_random
        );
        assert_eq!(
            app.environment.as_ref().unwrap().time_seconds,
            first_environment_time + 0.5
        );
        assert_eq!(app.frames_presented, 1);
    }

    #[test]
    fn replay_environment_delta_uses_last_applied_clock_and_keeps_duplicates_at_zero() {
        let initial = control_clock_ms_for_frame(500, 0, 101);
        assert_eq!(initial, 0);
        assert_eq!(replay_environment_delta_seconds(0, initial), 0.0);

        let first = control_clock_ms_for_frame(500, 1, 101);
        let repeated = control_clock_ms_for_frame(500, 1, 101);
        assert_eq!(replay_environment_delta_seconds(initial, first), 0.005);
        assert_eq!(replay_environment_delta_seconds(first, repeated), 0.0);
        let next = control_clock_ms_for_frame(500, 2, 101);
        assert_eq!(replay_environment_delta_seconds(first, next), 0.005);
        assert_eq!(
            replay_environment_delta_seconds(0, control_clock_ms_for_frame(500, 0, 1)),
            0.5
        );
        assert_eq!(replay_environment_delta_seconds(next, 0), 0.0);
    }

    #[test]
    fn ambient_effect_screen_bounds_follow_vulkan_viewport_y_direction() {
        let vertices = [
            [-0.5, 0.25, 0.5],
            [-0.5, 0.75, 0.5],
            [0.5, 0.75, 0.5],
            [0.5, 0.25, 0.5],
        ];
        let bounds = ambient_effect_projected_bounds(
            &vertices,
            [
                1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0,
            ],
            [100, 100],
        )
        .expect("visible clip-space quad");
        assert_eq!(bounds, [25.0, 62.5, 75.0, 87.5]);
    }

    #[test]
    fn native_tl_sprite_pixels_map_to_current_vulkan_viewport_at_z_999() {
        let uv = [[0.0, 0.0], [0.0, 1.0], [1.0, 1.0], [1.0, 0.0]];
        let small = screen_tl_quad_vertices_pixels(
            [160.0, 120.0],
            40.0,
            30.0,
            [640.0, 480.0],
            [1.0; 3],
            1.0,
            uv,
        );
        let resized = screen_tl_quad_vertices_pixels(
            [320.0, 240.0],
            80.0,
            60.0,
            [1280.0, 960.0],
            [1.0; 3],
            1.0,
            uv,
        );

        for (small, resized) in small.iter().zip(resized) {
            for axis in 0..2 {
                assert!((small.position[axis] - resized.position[axis]).abs() < 1.0e-6);
            }
            assert_eq!(small.position[2], 0.999);
            assert_eq!(resized.position[2], 0.999);
        }
        for (actual, expected) in [
            (small[0].position, [-0.625, -0.375, 0.999]),
            (small[2].position, [-0.625, -0.625, 0.999]),
        ] {
            for axis in 0..3 {
                assert!((actual[axis] - expected[axis]).abs() < 1.0e-6);
            }
        }
        assert_eq!(small[0].uv, [0.0, 1.0]);
        assert_eq!(small[2].uv, [0.0, 0.0]);
    }

    #[test]
    fn parses_control_clock_capture() {
        let parsed = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--frames",
            "101",
            "--control-clock-ms",
            "500",
        ]))
        .expect("controlled clock capture arguments");
        assert_eq!(parsed.control_clock_ms, Some(500));
        assert!(Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--control-clock-ms",
            "500",
        ]))
        .expect_err("replay needs multiple frames")
        .contains("at least 2"));
    }

    #[test]
    fn lightmap_ranges_stay_on_the_decorated_variant_when_phase_changes() {
        let empty_mat0 = Mat0Document {
            version: 0,
            animation_block_count: 0,
            phases: Vec::new(),
            prefix: Vec::new(),
            header_opaque: [0; 2],
            animation_blocks: Vec::new(),
        };
        let mut bindings = vec![MaterialAnimationBinding {
            initial_phase_index: 0,
            normalized_phase_override: None,
            ambient_fx_material_alpha: false,
            variants: vec![MaterialVariantSet {
                phase_material_indices: vec![10, 11],
                range_indices: Vec::new(),
                pipeline_category: 0,
            }],
            base: MaterialPhaseBinding {
                document: empty_mat0,
                animation_block_index: 0,
                wear_row_start_ms: 0,
                random_state: 0,
                frozen_phase_index: Some(0),
                phase_uv_transforms: Vec::new(),
            },
            detail: None,
            overlay: None,
            overlay_detail: None,
            stage_textures: None,
        }];
        let (binding_index, source_phases) =
            find_material_animation_variant(&bindings, 10).expect("base material variant");
        assert_eq!(source_phases, vec![10, 11]);
        bindings[binding_index].variants.push(MaterialVariantSet {
            phase_material_indices: vec![20, 21],
            range_indices: vec![7],
            pipeline_category: 0,
        });

        let lightmap_variant = &bindings[binding_index].variants[1];
        assert_eq!(lightmap_variant.range_indices, vec![7]);
        assert_eq!(
            selected_material_variant_index(lightmap_variant, 0),
            Some(20)
        );
        assert_eq!(
            selected_material_variant_index(lightmap_variant, 1),
            Some(21)
        );
    }

    fn row_vector_transform(point: [f32; 4], matrix: [f32; 16]) -> [f32; 4] {
        let mut result = [0.0; 4];
        for column in 0..4 {
            result[column] = (0..4)
                .map(|row| point[row] * matrix[row * 4 + column])
                .sum();
        }
        result
    }

    #[test]
    fn free_flight_camera_uses_right_handed_z_up_basis_and_positive_depth() {
        let camera = FreeFlightCamera {
            position: [0.0, 0.0, 0.0],
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: std::f32::consts::FRAC_PI_2,
            near_plane: 1.0,
            far_plane: 11.0,
            move_speed: 1.0,
            ground_clearance: 0.0,
        };

        let nearly_equal = |left: f32, right: f32| assert!((left - right).abs() < 1.0e-5);
        assert_eq!(camera.forward(), [1.0, 0.0, 0.0]);
        assert_eq!(camera.right(), [0.0, -1.0, 0.0]);
        assert_eq!(camera.up(), [0.0, 0.0, 1.0]);
        let matrix = camera.vulkan_camera(1.0).clip_from_world;
        let near = row_vector_transform([1.0, 0.0, 0.0, 1.0], matrix);
        let far = row_vector_transform([11.0, 0.0, 0.0, 1.0], matrix);
        let camera_right = row_vector_transform([1.0, -1.0, 0.0, 1.0], matrix);
        let world_up = row_vector_transform([1.0, 0.0, 1.0, 1.0], matrix);
        nearly_equal(near[0], 0.0);
        nearly_equal(near[1], 0.0);
        nearly_equal(near[2], 0.0);
        nearly_equal(near[3], 1.0);
        assert!(camera_right[0] / camera_right[3] > 0.0);
        assert!(world_up[1] / world_up[3] < 0.0);
        nearly_equal(far[2] / far[3], 1.0);
    }

    #[test]
    fn free_flight_camera_uses_native_horizontal_fov_for_every_viewport_aspect() {
        let horizontal_fov = 1.3_f32;
        let camera =
            FreeFlightCamera::from_bounds([0.0; 3], [100.0; 3]).expect("finite free-flight bounds");
        assert_eq!(camera.horizontal_fov, horizontal_fov);
        assert_eq!(camera.near_plane, 0.5);
        assert_eq!(camera.far_plane, 700.0);

        let assert_edges = |frame: PreviewCameraFrame, aspect: f32| {
            let expected_vertical_fov = 2.0 * ((horizontal_fov * 0.5).tan() / aspect).atan();
            assert!((frame.vertical_fov - expected_vertical_fov).abs() < 1.0e-5);
            let depth = 10.0;
            let center = add3(frame.position, scale3(frame.forward, depth));
            let right_edge = add3(
                center,
                scale3(frame.right, depth * (horizontal_fov * 0.5).tan()),
            );
            let top_edge = add3(
                center,
                scale3(frame.up, depth * (expected_vertical_fov * 0.5).tan()),
            );
            let center_clip = row_vector_transform(
                [center[0], center[1], center[2], 1.0],
                frame.clip_from_world,
            );
            let right_clip = row_vector_transform(
                [right_edge[0], right_edge[1], right_edge[2], 1.0],
                frame.clip_from_world,
            );
            let top_clip = row_vector_transform(
                [top_edge[0], top_edge[1], top_edge[2], 1.0],
                frame.clip_from_world,
            );
            assert!(center_clip[3] > 0.0 && right_clip[3] > 0.0 && top_clip[3] > 0.0);
            assert!(
                center_clip[0].abs() < 5.0e-4,
                "aspect {aspect}: {center_clip:?}"
            );
            assert!(
                center_clip[1].abs() < 5.0e-4,
                "aspect {aspect}: {center_clip:?}"
            );
            assert!(
                (right_clip[0] / right_clip[3] - 1.0).abs() < 1.0e-4,
                "aspect {aspect}: {right_clip:?}"
            );
            assert!(
                (top_clip[1] / top_clip[3] + 1.0).abs() < 1.0e-4,
                "aspect {aspect}: {top_clip:?}"
            );
        };

        for aspect in [0.05, 0.75, 4.0 / 3.0, 16.0 / 9.0, 20.0] {
            assert_edges(camera.preview_frame(aspect), aspect);

            let projection = LegacyD3d7Projection {
                viewport: [0, 0, 1000, (1000.0 / aspect).round() as i32],
                near_plane: 0.5,
                far_plane: 700.0,
                field_of_view_radians: horizontal_fov,
            };
            let raw_transform = RawCameraTransform {
                words: [
                    1.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    1.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    1.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    1.0_f32.to_bits(),
                ],
            };
            let captured = PreviewCameraFrame::from_legacy_d3d7(raw_transform, projection)
                .expect("valid D3D7 projection");
            assert_edges(
                captured,
                projection.viewport[2] as f32 / projection.viewport[3] as f32,
            );
        }
    }

    #[test]
    fn direction_projection_accepts_front_offscreen_rays_but_rejects_horizon() {
        let camera = FreeFlightCamera {
            position: [0.0; 3],
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: 1.3,
            near_plane: 0.5,
            far_plane: 700.0,
            move_speed: 1.0,
            ground_clearance: 0.0,
        }
        .preview_frame(16.0 / 9.0);
        let viewport = [1280.0, 720.0];
        let offscreen = project_direction_pixels(&camera, [0.2, 0.979_795_9, 0.0], viewport)
            .expect("front-facing directions are not rejected by the near distance");
        assert!(offscreen[0] < 0.0 || offscreen[0] > viewport[0]);
        assert!(project_direction_pixels(&camera, [1.0e-5, 1.0, 0.0], viewport).is_none());
        assert!(project_direction_pixels(&camera, [-1.0, 0.0, 0.0], viewport).is_none());

        let ray = screen_ray_from_pixels(&camera, [viewport[0] * 1.1, viewport[1] * 0.5], viewport)
            .expect("an offscreen pixel still has a view ray");
        let ray_pixels = project_direction_pixels(&camera, ray, viewport)
            .expect("the offscreen ray remains in the front hemisphere");
        assert!((ray_pixels[0] - viewport[0] * 1.1).abs() < 1.0e-3);
        assert!((ray_pixels[1] - viewport[1] * 0.5).abs() < 1.0e-3);
    }

    #[test]
    fn native_sky_heading_selects_matching_gradient_sectors_for_both_camera_origins() {
        use fparkan_fx::atmosphere::{PackedColor, SkySample, SKY_COLOR_COUNT};

        let mut colors = [PackedColor(0xFF00_0000); SKY_COLOR_COUNT];
        colors[..4].copy_from_slice(&[
            PackedColor(0xFF11_0000),
            PackedColor(0xFF00_2200),
            PackedColor(0xFF00_0033),
            PackedColor(0xFF44_4400),
        ]);
        let sample = SkySample {
            colors,
            values: [0.0; 2],
            packed: [PackedColor(0); 2],
        };
        let projection = LegacyD3d7Projection {
            viewport: [0, 0, 1280, 720],
            near_plane: 0.5,
            far_plane: 700.0,
            field_of_view_radians: 1.596_851_4,
        };

        let cardinal_forwards: [([f32; 3], usize); 4] = [
            ([0.0, 1.0, 0.0], 0),
            ([1.0, 0.0, 0.0], 1),
            ([0.0, -1.0, 0.0], 2),
            ([-1.0, 0.0, 0.0], 3),
        ];
        for (forward, sector) in cardinal_forwards {
            let free_flight = FreeFlightCamera {
                position: [0.0; 3],
                yaw: forward[1].atan2(forward[0]),
                pitch: 0.0,
                horizontal_fov: projection.field_of_view_radians,
                near_plane: projection.near_plane,
                far_plane: projection.far_plane,
                move_speed: 1.0,
                ground_clearance: 0.0,
            }
            .preview_frame(1280.0 / 720.0);

            let right = normalize3(cross3(forward, [0.0, 0.0, 1.0])).expect("camera right");
            let up = normalize3(cross3(right, forward)).expect("camera up");
            let raw_transform = RawCameraTransform {
                words: [
                    forward[0].to_bits(),
                    (-right[0]).to_bits(),
                    up[0].to_bits(),
                    0.0_f32.to_bits(),
                    forward[1].to_bits(),
                    (-right[1]).to_bits(),
                    up[1].to_bits(),
                    0.0_f32.to_bits(),
                    forward[2].to_bits(),
                    (-right[2]).to_bits(),
                    up[2].to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    0.0_f32.to_bits(),
                    1.0_f32.to_bits(),
                ],
            };
            let captured = PreviewCameraFrame::from_legacy_d3d7(raw_transform, projection)
                .expect("captured camera frame");

            for (origin, camera) in [("free flight", free_flight), ("captured", captured)] {
                let gradient = fparkan_fx::sky::screen_gradient_frame(
                    &sample,
                    camera.native_sky_heading(),
                    [0.0; 3],
                );
                assert_eq!(
                    gradient.color, sample.colors[sector],
                    "{origin} camera heading for forward {forward:?}"
                );
            }
        }
    }

    #[test]
    fn captured_native_camera_uses_view_dependent_sky_fog_color() {
        use fparkan_fx::atmosphere::{PackedColor, SkySample, SKY_COLOR_COUNT};

        // Compact camera fields from the native 1493.337-second AutoDemo capture.
        let capture = parse_legacy_camera_capture(
            br#"{"schema":"fparkan-legacy-camera-v1","render_input_usable":true,"parented_camera":true,"effective_world_matrix_space":"world","effective_world_matrix_words":[1052770830,1064129158,991881820,1141874407,3211610778,1052772554,3144770972,1145115441,3146624790,3127057462,1065352580,1087889619,0,0,0,1065353216],"selector0_words":[1063123992,3204380634,996787387,3130169600,1056894806,1063125889,990301923,3129510813,3146181515,3070164857,1065352633,1080608413,0,0,0,1065353216],"viewport":[0,0,1280,1024],"near_plane":5.0,"far_plane":700.0,"field_of_view_radians":1.3,"atmosphere_seconds":1493.337}"#,
        )
        .expect("valid native camera fixture");
        let camera = capture.preview_camera_frame().expect("valid camera frame");

        let mut colors = [PackedColor(0xFF00_0000); SKY_COLOR_COUNT];
        colors[..4].copy_from_slice(&[
            PackedColor(0xFF38_3864),
            PackedColor(0xFF38_3864),
            PackedColor(0xFF40_4064),
            PackedColor(0xFF38_3864),
        ]);
        let sample = SkySample {
            colors,
            values: [0.0; 2],
            packed: [PackedColor(0); 2],
        };
        let fog_color =
            fparkan_fx::sky::screen_gradient_frame(&sample, camera.native_sky_heading(), [0.0; 3])
                .color;

        assert_eq!(capture.atmosphere_seconds, Some(1493.337));
        assert_eq!(fog_color, PackedColor(0xFF3E_3E64));
    }

    #[test]
    fn sky_normals_keep_native_signed_byte_scale_without_renormalizing() {
        assert_eq!(sky_normal([-128, 127, -64]), [-1.0, 127.0 / 128.0, -0.5]);
    }

    fn set_test_terrain_lod_slots(
        terrain: &mut fparkan_terrain_format::LandMeshDocument,
        node_slots: &[[u16; 2]],
        face_ranges: &[[u16; 2]],
    ) {
        const NODE_STRIDE: usize = 38;
        let mut nodes = vec![u8::MAX; node_slots.len() * NODE_STRIDE];
        for (node_index, [lod0_slot, lod1_slot]) in node_slots.iter().copied().enumerate() {
            let offset = node_index * NODE_STRIDE + 8;
            nodes[offset..offset + 2].copy_from_slice(&lod0_slot.to_le_bytes());
            nodes[offset + 2..offset + 4].copy_from_slice(&lod1_slot.to_le_bytes());
        }
        let mut slots = vec![[0_u8; 68]; face_ranges.len()];
        for (slot, [start, count]) in slots.iter_mut().zip(face_ranges.iter().copied()) {
            slot[..2].copy_from_slice(&start.to_le_bytes());
            slot[2..4].copy_from_slice(&count.to_le_bytes());
        }
        terrain.nodes_raw = nodes;
        terrain.slots.slots_raw = slots;
    }

    fn mission_root_for_basement(position: [f32; 3], raw_after_name: u32) -> MissionObjectDraft {
        MissionObjectDraft {
            original_id: None,
            resource_name_raw: b"BUILDS/example.dat".to_vec(),
            raw_after_resource: 0,
            identity_or_clan_raw: 0,
            raw_after_name,
            unit_dat_header_flags: Some(0x8000_0000),
            position,
            orientation_raw: [0.0; 3],
            scale: [1.0; 3],
            visual_ids: Vec::new(),
            properties: Vec::new(),
            unit_components: Vec::new(),
        }
    }

    #[test]
    fn basement_delta_updates_one_common_root_for_mesh_and_attached_component() {
        let roots = [
            mission_root_for_basement([1.0, 2.0, 100.0], 0),
            mission_root_for_basement([3.0, 4.0, 200.0], 1),
        ];
        let footprints = [
            MissionBasementFootprint {
                object_index: 0,
                outer: Vec::new(),
                inner: Vec::new(),
                flatten_inner_to_mean_outer_z: true,
            },
            MissionBasementFootprint {
                object_index: 1,
                outer: Vec::new(),
                inner: Vec::new(),
                flatten_inner_to_mean_outer_z: false,
            },
        ];
        let placements = [
            BasementPlacement {
                placement_delta: 12.5,
            },
            BasementPlacement {
                placement_delta: 25.0,
            },
        ];
        let adjusted = apply_basement_placement_deltas(&roots, &footprints, &placements)
            .expect("aligned native placements");
        assert_eq!(adjusted[0].position, [1.0, 2.0, 87.5]);
        assert_eq!(adjusted[1].position, roots[1].position);

        let transform = LegacyIron3dEulerTransform {
            translation: adjusted[0].position,
            orientation_radians: adjusted[0].orientation_raw,
        };
        assert_eq!(
            transform.try_transform_scaled_point([0.0, 0.0, 0.0], adjusted[0].scale),
            Some([1.0, 2.0, 87.5])
        );
        assert_eq!(
            transform.try_transform_scaled_point([0.0, 0.0, 4.0], adjusted[0].scale),
            Some([1.0, 2.0, 91.5]),
            "the attached component inherits the root shift once"
        );
    }

    #[test]
    fn basement_projection_shadows_and_queries_share_generated_base_only_faces() {
        let mut land = fparkan_terrain_format::LandMeshDocument {
            streams: Vec::new(),
            nodes_raw: Vec::new(),
            slots: fparkan_terrain_format::TerrainSlotTable {
                header_raw: Vec::new(),
                slots_raw: Vec::new(),
            },
            positions: vec![[0.0, 0.0, 5.0], [20.0, 0.0, 5.0], [0.0, 20.0, 5.0]],
            normals: vec![[127, 0, 0, 0], [0, 127, 0, 0], [0, 0, 127, 0]],
            uv0: vec![[256, 128], [1024, 256], [512, 1536]],
            accelerator: Vec::new(),
            aux14: Vec::new(),
            aux18: Vec::new(),
            faces: vec![fparkan_terrain_format::TerrainFace28 {
                flags: FullSurfaceMask(0x400),
                material_tag: 0xff00,
                aux_tag: 0,
                vertices: [0, 1, 2],
                neighbors: [None, None, None],
                tail_raw: [0; 8],
                raw: [0; 28],
            }],
        };
        set_test_terrain_lod_slots(&mut land, &[[0, u16::MAX]], &[[0, 1]]);
        let source_mesh = project_land_msh_to_static_mesh_in_world_space(&land)
            .expect("project one LOD0 terrain face");
        let source_world = TerrainWorld::from_land_msh(&land).expect("source terrain");
        let (empty_mesh, empty_shadows, empty_query) =
            prepare_static_terrain_geometry(&land, source_mesh.clone(), &source_world, None)
                .expect("keep unmodified terrain when there are no foundations");
        assert_eq!(empty_mesh, source_mesh);
        assert_eq!(empty_query.surface_count(), source_world.surface_count());
        assert_eq!(empty_shadows.len(), 1);
        assert!(empty_mesh
            .vertices
            .iter()
            .any(|vertex| vertex.normal != [0.0; 3]));
        assert!(empty_mesh
            .vertices
            .iter()
            .any(|vertex| vertex.uv != [0.0; 2]));
        let band_positions = [
            [-18.25, -18.25, 5.0],
            [-2.25, -18.25, 5.0],
            [-18.25, -2.25, 5.0],
        ];
        let mut foundation = BasementFoundation {
            fragments: vec![
                BasementFoundationFragment {
                    source_face: Some(0),
                    surface_mask: FullSurfaceMask(0x400),
                    positions: [[0.0, 0.0, 5.0], [20.0, 0.0, 5.0], [0.0, 20.0, 5.0]],
                },
                BasementFoundationFragment {
                    source_face: None,
                    surface_mask: FullSurfaceMask(0x8300),
                    positions: band_positions,
                },
            ],
            placements: Vec::new(),
        };
        let (render_mesh, shadow_receivers) =
            project_basement_foundation(&land, &source_mesh, &mut foundation)
                .expect("project canonical basement faces");
        let expected = foundation.fragments.clone();
        assert_eq!(render_mesh.draw_ranges.len(), 2);
        assert!(render_mesh
            .draw_ranges
            .iter()
            .all(|range| range.material_index == 0xff00));
        assert!(!render_mesh.draw_ranges[0].terrain_base_only);
        assert!(render_mesh.draw_ranges[1].terrain_base_only);
        assert_eq!(render_mesh.draw_ranges[1].first_index, 3);
        assert_eq!(shadow_receivers.len(), expected.len());

        for (triangle_index, fragment) in expected.iter().enumerate() {
            let indices: [u32; 3] = render_mesh.indices[triangle_index * 3..triangle_index * 3 + 3]
                .try_into()
                .expect("projected foundation triangle");
            let positions = indices.map(|index| render_mesh.vertices[index as usize].position);
            assert_eq!(positions, fragment.positions);
            assert_eq!(
                shadow_receivers[triangle_index].positions,
                fragment.positions
            );
            assert_eq!(
                shadow_receivers[triangle_index].mask,
                fragment.surface_mask.0
            );
        }
        assert_eq!(
            basement_band_uv_vertices(band_positions)
                .expect("native per-face UVs")
                .map(|vertex| vertex.uv0),
            [[815, 815], [1896, 815], [815, 1896]],
            "negative coordinates use one native floor origin per triangle"
        );
        assert!(render_mesh.vertices[3..6]
            .iter()
            .flat_map(|vertex| vertex.uv)
            .all(|value| (value * 1024.0).fract() == 0.0));

        let query_world = source_world
            .with_basement_foundation(foundation)
            .expect("install canonical geometry");
        assert_eq!(query_world.surface_count(), expected.len());
        assert_eq!(
            query_world
                .basement_foundation()
                .expect("installed foundation")
                .fragments,
            expected
        );
        assert_eq!(query_world.height_at([-14.0, -14.0]).unwrap(), Some(5.0));
    }

    #[test]
    fn basement_band_normals_sum_packed_faces_for_native_welded_vertices() {
        let mut foundation = BasementFoundation {
            fragments: vec![
                BasementFoundationFragment {
                    source_face: None,
                    surface_mask: FullSurfaceMask(0x8300),
                    positions: [[0.0, 0.0, 0.0], [1.0, 0.0, 0.0], [0.0, 1.0, 0.0]],
                },
                BasementFoundationFragment {
                    source_face: None,
                    surface_mask: FullSurfaceMask(0x8300),
                    positions: [[0.005, 0.0, 0.0], [0.0, 1.0, 0.0], [1.0, 1.0, 1.0]],
                },
            ],
            placements: Vec::new(),
        };
        let (normals, uv0_words) = canonicalize_basement_band_vertices(&mut foundation)
            .expect("native packed normal pass");
        let first = normals[0].expect("first synthetic face");
        let second = normals[1].expect("second synthetic face");
        assert_eq!(first[0], second[0], "sub-centimeter XY vertices are welded");
        assert_eq!(foundation.fragments[1].positions[0], [0.0, 0.0, 0.0]);
        assert_eq!(
            first[2], second[1],
            "shared vertices use both packed face normals"
        );
        assert_eq!(uv0_words[1].expect("second face UV words")[0], [0, 0]);
        assert_eq!(first[0][1], 0.0);
        assert_ne!(first[0], [0.0, 0.0, 127.0 / 128.0]);
    }

    #[test]
    fn basement_face_normal_distinguishes_degenerate_from_non_finite() {
        assert_eq!(
            packed_basement_face_normal([[0.0; 3], [1.0; 3], [2.0; 3]])
                .expect("zero normal is a native zero contribution"),
            None
        );
        assert!(packed_basement_face_normal([
            [f32::NAN, 0.0, 0.0],
            [1.0, 0.0, 0.0],
            [0.0, 1.0, 0.0]
        ])
        .is_err());
    }

    #[test]
    fn c00_m02_world_terrain_edge_rounding_keeps_overlay_alpha_in_range() {
        // DATA/MAPS/Tut_2/Land.msh face 2525: this split point lands about
        // 1.35e-6 outside one source edge after the contour kernel's f32
        // world-coordinate output is converted back to f64 barycentrics.
        let source = [
            VulkanStaticVertex {
                position: [815.20465, 281.67642, 320.0],
                color: [1.0; 3],
                normal: [0.0, 0.0, 1.0],
                uv: [0.0; 2],
                detail_uv: [0.0; 2],
                overlay_alpha: 1.0,
            },
            VulkanStaticVertex {
                position: [775.4386, 308.18713, 360.00003],
                color: [1.0; 3],
                normal: [0.0, 0.0, 1.0],
                uv: [0.0; 2],
                detail_uv: [0.0; 2],
                overlay_alpha: 1.0,
            },
            VulkanStaticVertex {
                position: [775.4386, 288.3041, 361.6667],
                color: [1.0; 3],
                normal: [0.0, 0.0, 1.0],
                uv: [0.0; 2],
                detail_uv: [0.0; 2],
                overlay_alpha: 1.0,
            },
        ];
        let split_position = [800.6648, 291.3697, 334.62543];
        let point = [f64::from(split_position[0]), f64::from(split_position[1])];
        let a = [
            f64::from(source[0].position[0]),
            f64::from(source[0].position[1]),
        ];
        let b = [
            f64::from(source[1].position[0]),
            f64::from(source[1].position[1]),
        ];
        let c = [
            f64::from(source[2].position[0]),
            f64::from(source[2].position[1]),
        ];
        let denominator = (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0]);
        let second_weight =
            ((point[0] - a[0]) * (c[1] - a[1]) - (point[1] - a[1]) * (c[0] - a[0])) / denominator;
        let third_weight =
            ((b[0] - a[0]) * (point[1] - a[1]) - (b[1] - a[1]) * (point[0] - a[0])) / denominator;
        let raw_overlay_alpha = [
            1.0 - second_weight - third_weight,
            second_weight,
            third_weight,
        ]
        .map(|weight| weight as f32)
        .into_iter()
        .sum::<f32>();
        assert!(raw_overlay_alpha > 1.0 && raw_overlay_alpha <= 1.0 + 1.0e-5);
        let vertex = interpolate_static_terrain_vertex(split_position, source)
            .expect("bounded alpha rounding at a contour split");
        assert_eq!(vertex.overlay_alpha, 1.0);
        assert!((0.0..=1.0).contains(&vertex.overlay_alpha));
    }

    #[test]
    fn sun_visibility_uses_a_valid_ray_and_fails_open_without_surfaces() {
        let camera = FreeFlightCamera {
            position: [10.0, 20.0, 30.0],
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: 1.0,
            near_plane: 0.1,
            far_plane: 100.0,
            move_speed: 1.0,
            ground_clearance: 0.0,
        }
        .preview_frame(16.0 / 9.0);
        let terrain = TerrainWorld::default();
        assert!(native_sun_unoccluded(&terrain, &camera, [1.0, 0.0, 0.0]));
        assert!(!native_sun_unoccluded(&terrain, &camera, [0.0, 0.0, 0.0]));

        let mut land = fparkan_terrain_format::LandMeshDocument {
            streams: Vec::new(),
            nodes_raw: Vec::new(),
            slots: fparkan_terrain_format::TerrainSlotTable {
                header_raw: Vec::new(),
                slots_raw: Vec::new(),
            },
            // Nonzero source Z is shared by the camera, terrain and shadows.
            positions: vec![[0.0, 0.0, 32.0], [1.0, 0.0, 32.0], [0.0, 1.0, 32.0]],
            normals: Vec::new(),
            uv0: Vec::new(),
            accelerator: Vec::new(),
            aux14: Vec::new(),
            aux18: Vec::new(),
            faces: vec![fparkan_terrain_format::TerrainFace28 {
                flags: FullSurfaceMask(1),
                material_tag: 0,
                aux_tag: 0,
                vertices: [0, 1, 2],
                neighbors: [None, None, None],
                tail_raw: [0; 8],
                raw: [0; 28],
            }],
        };
        set_test_terrain_lod_slots(&mut land, &[[0, u16::MAX]], &[[0, 1]]);
        let shadow_receivers = terrain_shadow_receivers(&land).expect("raw-height receivers");
        assert_eq!(shadow_receivers[0].positions[0], [0.0, 0.0, 32.0]);
        let terrain = TerrainWorld::from_land_msh(&land).expect("synthetic terrain");
        assert_eq!(terrain.height_at([0.25, 0.25]).unwrap(), Some(32.0));
        let floor_camera =
            FreeFlightCamera::from_mesh_and_terrain(&VulkanStaticMesh::smoke_triangle(), &terrain)
                .expect("camera above nonzero terrain");
        assert_eq!(floor_camera.position[2], 34.0);
        assert_eq!(floor_camera.ground_clearance, 2.0);
        let blocked_camera = FreeFlightCamera {
            position: [0.25, 0.25, 34.0],
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: 1.0,
            near_plane: 0.1,
            far_plane: 100.0,
            move_speed: 1.0,
            ground_clearance: 0.0,
        }
        .preview_frame(16.0 / 9.0);
        assert!(!native_sun_unoccluded(
            &terrain,
            &blocked_camera,
            [0.0, 0.0, -1.0]
        ));

        // The same hit is beyond a short native sun segment, so it must not
        // occlude the light even though the terrain contains a surface.
        let short_segment_camera = PreviewCameraFrame {
            far_plane: 1.0,
            ..blocked_camera
        };
        assert!(native_sun_unoccluded(
            &terrain,
            &short_segment_camera,
            [0.0, 0.0, -1.0]
        ));

        let world_mesh = VulkanStaticMesh::smoke_triangle();
        assert!(!native_sun_unoccluded_with_world(
            &TerrainWorld::default(),
            &world_mesh,
            &[0],
            &blocked_camera,
            [0.0, 0.0, -1.0]
        ));
        assert!(native_sun_unoccluded_with_world(
            &TerrainWorld::default(),
            &world_mesh,
            &[],
            &blocked_camera,
            [0.0, 0.0, -1.0]
        ));

        let mut excluded_land = fparkan_terrain_format::LandMeshDocument {
            streams: Vec::new(),
            nodes_raw: Vec::new(),
            slots: fparkan_terrain_format::TerrainSlotTable {
                header_raw: Vec::new(),
                slots_raw: Vec::new(),
            },
            positions: vec![[0.0, 0.0, 32.0], [1.0, 0.0, 32.0], [0.0, 1.0, 32.0]],
            normals: Vec::new(),
            uv0: Vec::new(),
            accelerator: Vec::new(),
            aux14: Vec::new(),
            aux18: Vec::new(),
            faces: vec![fparkan_terrain_format::TerrainFace28 {
                flags: FullSurfaceMask(0x20),
                material_tag: 0,
                aux_tag: 0,
                vertices: [0, 1, 2],
                neighbors: [None, None, None],
                tail_raw: [0; 8],
                raw: [0; 28],
            }],
        };
        set_test_terrain_lod_slots(&mut excluded_land, &[[0, u16::MAX]], &[[0, 1]]);
        let excluded_terrain =
            TerrainWorld::from_land_msh(&excluded_land).expect("excluded terrain");
        assert!(native_sun_unoccluded_with_world(
            &excluded_terrain,
            &world_mesh,
            &[],
            &blocked_camera,
            [0.0, 0.0, -1.0]
        ));

        let mut excluded_world_mesh = world_mesh.clone();
        excluded_world_mesh.draw_ranges[0].batch_flags = 0x0008;
        assert!(native_sun_unoccluded_with_world(
            &TerrainWorld::default(),
            &excluded_world_mesh,
            &[0],
            &blocked_camera,
            [0.0, 0.0, -1.0]
        ));
    }

    #[test]
    fn free_flight_camera_keeps_clearance_after_descending_and_moving_uphill() {
        let mut land = fparkan_terrain_format::LandMeshDocument {
            streams: Vec::new(),
            nodes_raw: Vec::new(),
            slots: fparkan_terrain_format::TerrainSlotTable {
                header_raw: Vec::new(),
                slots_raw: Vec::new(),
            },
            positions: vec![[0.0, 0.0, 32.0], [1.0, 0.0, 34.0], [0.0, 1.0, 36.0]],
            normals: Vec::new(),
            uv0: Vec::new(),
            accelerator: Vec::new(),
            aux14: Vec::new(),
            aux18: Vec::new(),
            faces: vec![fparkan_terrain_format::TerrainFace28 {
                flags: FullSurfaceMask(1),
                material_tag: 0,
                aux_tag: 0,
                vertices: [0, 1, 2],
                neighbors: [None, None, None],
                tail_raw: [0; 8],
                raw: [0; 28],
            }],
        };
        set_test_terrain_lod_slots(&mut land, &[[0, u16::MAX]], &[[0, 1]]);
        let terrain = TerrainWorld::from_land_msh(&land).expect("sloped terrain");
        assert_eq!(terrain.height_at([0.25, 0.25]).unwrap(), Some(33.5));
        assert_eq!(terrain.height_at([0.75, 0.25]).unwrap(), Some(34.5));

        let mut camera = FreeFlightCamera {
            position: [0.25, 0.25, 37.0],
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: 1.0,
            near_plane: 0.1,
            far_plane: 100.0,
            move_speed: 4.0,
            ground_clearance: 2.0,
        };
        let mut keys = HashSet::from([KeyCode::KeyQ]);
        camera.advance(&keys, 1.0);
        camera
            .keep_above_terrain(&terrain)
            .expect("floor query after descent");
        assert_eq!(camera.position, [0.25, 0.25, 35.5]);

        keys.clear();
        keys.insert(KeyCode::KeyW);
        camera.move_speed = 1.0;
        camera.advance(&keys, 0.5);
        camera
            .keep_above_terrain(&terrain)
            .expect("floor query after uphill movement");
        assert_eq!(camera.position, [0.75, 0.25, 36.5]);

        let mut outside_camera = FreeFlightCamera {
            position: [2.0, -2.0, -17.0],
            ground_clearance: 2.0,
            ..camera
        };
        outside_camera
            .keep_above_terrain(&terrain)
            .expect("clamp to the map before sampling the floor");
        assert_eq!(outside_camera.position, [1.0, 0.0, 36.0]);

        outside_camera.position = [-2.0, 2.0, 100.0];
        outside_camera
            .keep_above_terrain(&terrain)
            .expect("clamp the other map edges without limiting altitude");
        assert_eq!(outside_camera.position, [0.0, 1.0, 100.0]);

        outside_camera.move_speed = 40.0;
        outside_camera.advance(&HashSet::from([KeyCode::KeyW, KeyCode::ShiftLeft]), 0.1);
        outside_camera
            .keep_above_terrain(&terrain)
            .expect("accelerated movement still stops at the map edge");
        assert_eq!(outside_camera.position, [1.0, 1.0, 100.0]);

        let mut unsupported_camera = FreeFlightCamera {
            position: [0.25, 0.25, 35.5],
            ground_clearance: 2.0,
            ..camera
        };
        assert!(unsupported_camera
            .keep_above_terrain(&TerrainWorld::default())
            .expect_err("terrain query errors must propagate")
            .contains("terrain height query"));
    }

    #[test]
    #[ignore = "requires the original GOG installation"]
    fn free_flight_camera_stops_at_original_map_edges_under_accelerated_movement() {
        let root = std::env::var_os("FPARKAN_CORPUS_PART1_ROOT")
            .expect("set FPARKAN_CORPUS_PART1_ROOT to the original GOG installation");
        let mut engine =
            create(EngineServices::new(Arc::new(DirectoryVfs::new(root)))).expect("engine");
        load_mission_static_preview(
            &mut engine,
            MissionRequest {
                key: "MISSIONS/Autodemo.00/data.tma".to_string(),
                mode: MissionMode::SingleMission,
            },
        )
        .expect("original mission");
        let terrain = loaded_terrain(&engine).expect("original terrain");
        let [min, max] = terrain.surface_bounds().expect("original map bounds");
        let keys = HashSet::from([KeyCode::KeyW, KeyCode::ShiftLeft]);
        for (axis, yaw, edge) in [
            (0, 0.0, max[0]),
            (0, std::f32::consts::PI, min[0]),
            (1, std::f32::consts::FRAC_PI_2, max[1]),
            (1, -std::f32::consts::FRAC_PI_2, min[1]),
        ] {
            let mut camera = FreeFlightCamera::from_bounds(min, max).expect("camera");
            camera.position = [
                (min[0] + max[0]) * 0.5,
                (min[1] + max[1]) * 0.5,
                max[2] + 10.0,
            ];
            camera.yaw = yaw;
            camera.pitch = 0.0;
            for _ in 0..512 {
                camera.advance(&keys, 0.1);
                camera.keep_above_terrain(terrain).expect("map constraint");
                for axis in 0..2 {
                    assert!((min[axis]..=max[axis]).contains(&camera.position[axis]));
                }
            }
            assert_eq!(camera.position[axis], edge);
        }
    }

    #[test]
    fn world_sort_key_uses_the_first_indexed_vertex() {
        let mesh = VulkanStaticMesh::smoke_triangle();
        let distance = first_indexed_vertex_distance(&mesh, 0, [0.0, -0.55, -3.0])
            .expect("first indexed vertex distance");
        assert!((distance - 3.0).abs() < 1.0e-6);
    }

    #[test]
    fn free_flight_camera_advances_wasd_and_vertical_controls() {
        let mut camera = FreeFlightCamera {
            position: [0.0, 0.0, 0.0],
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: 1.0,
            near_plane: 0.1,
            far_plane: 100.0,
            move_speed: 2.0,
            ground_clearance: 0.0,
        };
        let mut keys = HashSet::new();
        keys.insert(KeyCode::KeyW);
        keys.insert(KeyCode::KeyD);
        camera.advance(&keys, 1.0);
        let diagonal = 2.0 / 2.0_f32.sqrt();
        assert!((camera.position[0] - diagonal).abs() < 1.0e-5);
        assert!((camera.position[1] + diagonal).abs() < 1.0e-5);
        assert_eq!(camera.position[2], 0.0);

        keys.clear();
        keys.insert(KeyCode::KeyE);
        keys.insert(KeyCode::ShiftLeft);
        camera.advance(&keys, 0.5);
        assert!((camera.position[2] - 4.0).abs() < 1.0e-5);
    }

    #[test]
    fn free_flight_mouse_right_turns_toward_previous_right_and_vertical_is_world_z() {
        let mut camera = FreeFlightCamera {
            position: [0.0, 0.0, 0.0],
            yaw: 0.0,
            pitch: 0.6,
            horizontal_fov: 1.0,
            near_plane: 0.1,
            far_plane: 100.0,
            move_speed: 2.0,
            ground_clearance: 0.0,
        };
        let old_right = camera.right();
        let old_forward = camera.forward();
        camera.look_delta(100.0, 0.0);
        assert!(dot3(camera.forward(), old_right) > 0.0);
        assert!(dot3(camera.forward(), old_forward) < 1.0);

        let mut keys = HashSet::new();
        keys.insert(KeyCode::KeyE);
        camera.advance(&keys, 0.5);
        assert!((camera.position[0]).abs() < 1.0e-5);
        assert!((camera.position[1]).abs() < 1.0e-5);
        assert!((camera.position[2] - 1.0).abs() < 1.0e-5);
    }

    #[test]
    fn parses_validation_flag() {
        let parsed = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--validation",
        ]))
        .expect("valid validation flag");
        assert!(parsed.validation);
    }

    #[test]
    fn parses_nonzero_static_preview_root_count() {
        let parsed = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--preview-roots",
            "2",
        ]))
        .expect("valid static preview arguments");
        assert_eq!(
            parsed.preview_roots,
            NonZeroUsize::new(2).expect("non-zero literal")
        );
    }

    #[test]
    fn parses_readback_output() {
        let parsed = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--readback-out",
            "target/frame.raw",
        ]))
        .expect("valid readback output arguments");
        assert_eq!(parsed.readback_out, Some(PathBuf::from("target/frame.raw")));
    }

    #[test]
    fn controlled_readback_sequence_requires_and_parses_replay_clock() {
        let parsed = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--frames",
            "11",
            "--control-clock-ms",
            "0",
            "--readback-sequence-out",
            "target/frames",
        ]))
        .expect("valid fixed-clock readback sequence");
        assert_eq!(
            parsed.readback_sequence_out,
            Some(PathBuf::from("target/frames"))
        );
        assert_eq!(parsed.control_clock_ms, Some(0));

        let error = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--frames",
            "11",
            "--readback-sequence-out",
            "target/frames",
        ]))
        .expect_err("sequence captures need deterministic clock input");
        assert!(error.contains("requires --control-clock-ms"));
    }

    #[test]
    fn readback_sequence_writes_clock_named_frame_without_overwrite() {
        let nonce = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .expect("system clock after epoch")
            .as_nanos();
        let directory = std::env::temp_dir().join(format!(
            "fparkan-readback-sequence-{}-{nonce}",
            std::process::id()
        ));
        let artifact = VulkanReadbackArtifact {
            format: 37,
            width: 2,
            height: 1,
            bytes: vec![1, 2, 3, 4, 5, 6, 7, 8],
        };
        let path = write_readback_sequence_frame(&directory, 3, 50, &artifact)
            .expect("write frame artifact");
        assert_eq!(
            path.file_name().and_then(|name| name.to_str()),
            Some("frame-000003-clock-0000000050ms-2x1.rgba")
        );
        assert_eq!(
            std::fs::read(&path).expect("read frame artifact"),
            artifact.bytes
        );
        assert!(write_readback_sequence_frame(&directory, 3, 50, &artifact).is_err());
        std::fs::remove_dir_all(directory).expect("remove frame artifact directory");
    }

    #[test]
    fn parses_static_animation_frame() {
        let parsed = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--static-animation-frame",
            "12",
        ]))
        .expect("valid static animation frame");
        assert_eq!(parsed.static_animation_frame, Some(12));
    }

    #[test]
    fn static_preview_control_defaults_apply_native_flags_and_last_row_wins() {
        let binding =
            |node_index, frame_a, frame_b, initial_blend, flags| PreparedControlNodeBinding {
                node_index,
                frame_a,
                frame_b,
                initial_blend,
                flags,
            };
        let times = static_preview_node_times(
            6,
            &[
                binding(1, 1.0, 3.0, 0.0, 0),
                binding(2, 1.0, 3.0, 1.25, 1),
                binding(3, 1.0, 3.0, -0.5, 1),
                binding(4, 1.0, 3.0, -0.5, 0),
                binding(1, 1.0, 3.0, 0.25, 2),
                binding(usize::MAX, f32::NAN, f32::INFINITY, f32::NAN, 4),
            ],
        )
        .expect("valid static CTLD defaults");
        let values = times
            .iter()
            .map(|time| time.map(|time| time.0))
            .collect::<Vec<_>>();
        assert_eq!(
            values,
            vec![
                Some(0.0),
                Some(2.5),
                Some(1.5),
                Some(2.0),
                Some(1.0),
                Some(0.0)
            ]
        );
    }

    #[test]
    fn static_preview_rejects_negative_derived_control_sample_time() {
        let error = static_preview_node_times(
            1,
            &[PreparedControlNodeBinding {
                node_index: 0,
                frame_a: 0.0,
                frame_b: 2.0,
                initial_blend: -2.0,
                flags: 1,
            }],
        )
        .expect_err("one wrap still leaves an unsupported negative sample time");
        assert!(error.contains("negative or non-finite sample time"));
    }

    #[test]
    fn parses_static_material_phase() {
        let parsed = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--static-material-phase",
            "2",
        ]))
        .expect("valid static material phase");
        assert_eq!(parsed.static_material_phase, Some(2));
    }

    #[test]
    fn rejects_zero_static_preview_root_count() {
        let error = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--preview-roots",
            "0",
        ]));
        assert_eq!(
            error,
            Err("--preview-roots must be a non-zero integer".to_string())
        );
    }

    #[test]
    fn parses_legacy_camera_capture_path() {
        let valid = Args::parse(&strings(&[
            "--root",
            "testdata/IS",
            "--mission",
            "MISSIONS/Autodemo.00/data.tma",
            "--legacy-camera-capture",
            "target/camera.json",
        ]))
        .expect("valid legacy camera arguments");
        assert_eq!(
            valid.legacy_camera_capture,
            Some(PathBuf::from("target/camera.json"))
        );
    }

    #[test]
    fn legacy_camera_capture_parses_exact_d3d7_inputs() {
        let words = [
            0.0_f32.to_bits(),
            (-1.0_f32).to_bits(),
            0.0_f32.to_bits(),
            10.0_f32.to_bits(),
            1.0_f32.to_bits(),
            0.0_f32.to_bits(),
            0.0_f32.to_bits(),
            20.0_f32.to_bits(),
            0.0_f32.to_bits(),
            0.0_f32.to_bits(),
            1.0_f32.to_bits(),
            30.0_f32.to_bits(),
            0.0_f32.to_bits(),
            0.0_f32.to_bits(),
            0.0_f32.to_bits(),
            1.0_f32.to_bits(),
        ];
        let json = format!(
            "{{\"schema\":\"fparkan-legacy-camera-v1\",\"render_input_usable\":true,\"atmosphere_seconds\":56.227,\"selector0_words\":{:?},\"viewport\":[23,17,1047,785],\"near_plane\":0.5,\"far_plane\":700.0,\"field_of_view_radians\":1.3}}",
            words
        );

        let capture = parse_legacy_camera_capture(json.as_bytes()).expect("valid legacy camera");
        let camera = capture.preview_camera_frame().expect("valid preview frame");

        assert_eq!(capture.render_input_usable, Some(true));
        assert_eq!(capture.atmosphere_seconds, Some(56.227));
        assert!(camera.clip_from_world.iter().all(|value| value.is_finite()));
        assert_eq!(camera.clip_from_world[0], 0.65_f32.cos());
        assert_eq!(capture.viewport, [23, 17, 1047, 785]);
        assert_eq!(
            capture.captured_viewport().unwrap().rect,
            [23, 17, 1047, 785]
        );
        assert_eq!(capture.captured_viewport().unwrap().extent, [1024, 768]);
        assert!((horizontal_fov(&camera, 4.0 / 3.0) - 1.3).abs() < 1.0e-5);
        assert_eq!(
            camera.vulkan_camera().clip_from_world,
            camera.clip_from_world
        );
        let mut utf16le = vec![0xff, 0xfe];
        utf16le.extend(json.encode_utf16().flat_map(u16::to_le_bytes));
        assert_eq!(
            parse_legacy_camera_capture(&utf16le)
                .expect("PowerShell UTF-16LE capture must be accepted")
                .preview_camera_frame()
                .expect("UTF-16 preview frame")
                .clip_from_world,
            camera.clip_from_world
        );
        assert_eq!(
            parse_legacy_camera_capture(br#"{"schema":"unknown","selector0_words":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"viewport":[0,0,1,1],"near_plane":0.1,"far_plane":1.0,"field_of_view_radians":1.0}"#),
            Err("unsupported legacy camera capture schema".to_string())
        );
    }

    #[test]
    fn parented_camera_preview_uses_effective_world_matrix_and_legacy_uses_local() {
        let local_words = [
            1065353216, 0, 0, 1065353216, 0, 1065353216, 0, 1073741824, 0, 0, 1065353216,
            1077936128, 0, 0, 0, 1065353216,
        ];
        let world_words = [
            1065353216, 0, 0, 1092616192, 0, 1065353216, 0, 1101004800, 0, 0, 1065353216,
            1106247680, 0, 0, 0, 1065353216,
        ];
        let make_json = |extra: &str| {
            format!(
                "{{\"schema\":\"fparkan-legacy-camera-v1\",\"render_input_usable\":true,\"selector0_words\":{:?},{}\"viewport\":[0,0,1280,1024],\"near_plane\":0.5,\"far_plane\":700.0,\"field_of_view_radians\":1.04}}",
                local_words, extra
            )
        };
        let legacy = parse_legacy_camera_capture(make_json("").as_bytes())
            .expect("legacy camera without parent metadata");
        assert_eq!(legacy.preview_matrix_words().unwrap(), local_words);
        assert_eq!(
            legacy.preview_camera_frame().unwrap().position,
            [1.0, 2.0, 3.0]
        );

        let parented = parse_legacy_camera_capture(
            make_json(&format!(
                "\"parented_camera\":true,\"effective_world_matrix_space\":\"world\",\"effective_world_matrix_words\":{:?},",
                world_words
            ))
            .as_bytes(),
        )
        .expect("parented camera with effective world matrix");
        assert_eq!(parented.preview_matrix_words().unwrap(), world_words);
        let preview = parented.preview_camera_frame().unwrap();
        assert_eq!(preview.position, [10.0, 20.0, 30.0]);
        assert_ne!(
            preview.position,
            legacy.preview_camera_frame().unwrap().position
        );

        let missing_world = make_json("\"parented_camera\":true,");
        assert!(parse_legacy_camera_capture(missing_world.as_bytes())
            .expect_err("parented local-only input must be rejected")
            .contains("parented legacy camera requires an effective world-space matrix"));
        let missing_marker = make_json(&format!(
            "\"parented_camera\":true,\"effective_world_matrix_words\":{:?},",
            world_words
        ));
        assert!(parse_legacy_camera_capture(missing_marker.as_bytes())
            .expect_err("world matrix requires space marker")
            .contains("effective_world_matrix_space and effective_world_matrix_words"));
    }

    #[test]
    fn parented_camera_preview_uses_effective_world_matrix_fixture() {
        let fixture = include_bytes!("../testdata/legacy-camera-parented.json");
        let capture = parse_legacy_camera_capture(fixture).expect("valid parented camera fixture");
        let parse_value = |value: serde_json::Value| {
            let bytes = serde_json::to_vec(&value).expect("serialize camera fixture");
            parse_legacy_camera_capture(&bytes)
        };
        assert_eq!(capture.parented_camera, Some(true));
        assert_eq!(
            capture.preview_camera_frame().unwrap().position,
            [10.0, 20.0, 30.0]
        );
        assert_eq!(
            capture.preview_matrix_words().unwrap(),
            capture.effective_world_matrix_words.unwrap()
        );

        let mut missing_world: serde_json::Value =
            serde_json::from_slice(fixture).expect("valid fixture JSON");
        missing_world
            .as_object_mut()
            .unwrap()
            .remove("effective_world_matrix_words");
        let missing_world = serde_json::to_vec(&missing_world).unwrap();
        assert!(parse_legacy_camera_capture(&missing_world)
            .expect_err("incomplete world matrix pair")
            .contains("effective_world_matrix_space and effective_world_matrix_words"));

        let mut parented_without_world: serde_json::Value =
            serde_json::from_slice(fixture).expect("valid fixture JSON");
        let parented_without_world = parented_without_world.as_object_mut().unwrap();
        parented_without_world.remove("effective_world_matrix_space");
        parented_without_world.remove("effective_world_matrix_words");
        assert!(
            parse_value(serde_json::Value::Object(parented_without_world.clone()))
                .expect_err("parented camera without its world matrix")
                .contains("parented legacy camera requires an effective world-space matrix")
        );

        let mut invalid_marker: serde_json::Value =
            serde_json::from_slice(fixture).expect("valid fixture JSON");
        invalid_marker["effective_world_matrix_space"] =
            serde_json::Value::String("local".to_string());
        assert!(parse_value(invalid_marker)
            .expect_err("unknown matrix space")
            .contains("effective_world_matrix_space must be 'world'"));

        let mut legacy: serde_json::Value =
            serde_json::from_slice(fixture).expect("valid fixture JSON");
        let legacy = legacy.as_object_mut().unwrap();
        legacy.remove("parented_camera");
        legacy.remove("effective_world_matrix_space");
        legacy.remove("effective_world_matrix_words");
        let legacy = parse_value(serde_json::Value::Object(legacy.clone()))
            .expect("older local-only camera capture");
        assert_eq!(
            legacy.preview_camera_frame().unwrap().position,
            [1.0, 2.0, 3.0]
        );
    }

    #[test]
    fn captured_atmosphere_is_default_and_cli_time_takes_precedence() {
        let capture = LegacyCameraCapture {
            schema: "fparkan-legacy-camera-v1".to_string(),
            render_input_usable: None,
            selector0_words: [0; 16],
            parented_camera: None,
            effective_world_matrix_space: None,
            effective_world_matrix_words: None,
            viewport: [0, 0, 1, 1],
            near_plane: 0.1,
            far_plane: 1.0,
            field_of_view_radians: 1.0,
            atmosphere_seconds: Some(56.227),
        };

        assert_eq!(
            selected_atmosphere_seconds(None, Some(&capture)),
            Some(56.227)
        );
        assert_eq!(
            selected_atmosphere_seconds(Some(100.0), Some(&capture)),
            Some(100.0)
        );
        assert_eq!(selected_atmosphere_seconds(None, None), None);
    }

    #[test]
    fn captured_environment_holds_exact_phase_while_free_time_advances() {
        let (fixed_relative, fixed_absolute) =
            environment_sample_time(0.227, 56.0, 0.25, Some(56.227));
        assert_eq!(fixed_relative, 0.227);
        assert_eq!(fixed_absolute, 56.227);

        let (free_relative, free_absolute) = environment_sample_time(0.227, 56.0, 0.25, None);
        assert_eq!(free_relative, 0.477);
        assert_eq!(free_absolute, 56.477);
    }

    #[test]
    fn legacy_camera_capture_rejects_invalid_phase_and_unusable_input() {
        let base = r#"{"schema":"fparkan-legacy-camera-v1","selector0_words":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"viewport":[0,0,1,1],"near_plane":0.1,"far_plane":1.0,"field_of_view_radians":1.0}"#;
        let invalid_phase = base.replace(
            "\"near_plane\"",
            "\"atmosphere_seconds\":-1.0,\"near_plane\"",
        );
        assert!(parse_legacy_camera_capture(invalid_phase.as_bytes())
            .expect_err("negative captured phase")
            .contains("atmosphere_seconds must be finite and non-negative"));

        let unusable = base.replace(
            "\"near_plane\"",
            "\"render_input_usable\":false,\"near_plane\"",
        );
        assert!(parse_legacy_camera_capture(unusable.as_bytes())
            .expect_err("explicitly unusable camera capture")
            .contains("render_input_usable=false"));
    }

    #[test]
    fn captured_camera_frame_keeps_native_roll_basis() {
        let roll = 0.37_f32;
        let (sin, cos) = roll.sin_cos();
        let transform = RawCameraTransform {
            words: [
                1.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                cos.to_bits(),
                (-sin).to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                sin.to_bits(),
                cos.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                0.0_f32.to_bits(),
                1.0_f32.to_bits(),
            ],
        };
        let projection = LegacyD3d7Projection {
            viewport: [0, 0, 800, 600],
            near_plane: 0.1,
            far_plane: 500.0,
            field_of_view_radians: 1.0,
        };
        let view = transform
            .try_direct3d7_view_row_major()
            .expect("valid native camera basis");
        let frame = PreviewCameraFrame::from_legacy_d3d7(transform, projection)
            .expect("valid captured frame");

        assert_eq!(frame.forward, [view[2], view[6], view[10]]);
        assert_eq!(frame.right, [view[0], view[4], view[8]]);
        assert_eq!(frame.up, [view[1], view[5], view[9]]);
        assert!(frame.right[2].abs() > 0.3, "roll must tilt the right axis");
        assert!(frame.up[1].abs() > 0.3, "roll must tilt the up axis");
        assert_eq!(
            frame.clip_from_world,
            VulkanStaticCamera::from_legacy_d3d7(transform, projection)
                .expect("legacy clip matrix")
                .clip_from_world
        );
    }

    #[test]
    fn captured_camera_refuses_a_different_drawable_extent() {
        let captured = CapturedViewport {
            rect: [23, 17, 1047, 785],
            extent: [1024, 768],
        };
        assert!(validate_captured_drawable_extent(captured, [1024, 768]).is_ok());
        let error = validate_captured_drawable_extent(captured, [1280, 720])
            .expect_err("a mismatched surface must not stretch the captured view");
        assert!(error.contains("[23, 17, 1047, 785]"));
        assert!(error.contains("1024x768"));
        assert!(error.contains("1280x720"));
    }

    #[test]
    fn static_preview_component_merge_offsets_indices_and_remaps_local_selectors(
    ) -> Result<(), String> {
        let mut merged = VulkanStaticMesh {
            vertices: Vec::new(),
            indices: Vec::new(),
            draw_ranges: Vec::new(),
        };
        append_static_preview_component(
            &mut merged,
            VulkanStaticMesh::smoke_triangle(),
            &[(0, 4)],
            None,
        )?;
        append_static_preview_component(
            &mut merged,
            VulkanStaticMesh::smoke_triangle(),
            &[(0, 9)],
            None,
        )?;

        assert_eq!(merged.vertices.len(), 6);
        assert_eq!(merged.indices, vec![0, 1, 2, 3, 4, 5]);
        assert_eq!(merged.draw_ranges.len(), 2);
        assert_eq!(merged.draw_ranges[0].first_index, 0);
        assert_eq!(merged.draw_ranges[0].material_index, 4);
        assert_eq!(merged.draw_ranges[1].first_index, 3);
        assert_eq!(merged.draw_ranges[1].material_index, 9);
        Ok(())
    }

    #[test]
    fn static_preview_component_merge_keeps_indices_above_u16() -> Result<(), String> {
        let vertex = fparkan_render_vulkan::VulkanStaticVertex {
            position: [0.0, 0.0, 0.0],
            color: [1.0, 1.0, 1.0],
            normal: [0.0, 0.0, 1.0],
            uv: [0.0, 0.0],
            detail_uv: [0.0, 0.0],
            overlay_alpha: 0.0,
        };
        let mut merged = VulkanStaticMesh {
            vertices: vec![vertex; usize::from(u16::MAX) + 1],
            indices: Vec::new(),
            draw_ranges: Vec::new(),
        };

        append_static_preview_component(
            &mut merged,
            VulkanStaticMesh::smoke_triangle(),
            &[(0, 0)],
            None,
        )?;

        assert_eq!(merged.indices, vec![65_536, 65_537, 65_538]);
        Ok(())
    }

    #[test]
    fn precipitation_upload_reconstructs_native_ndc_depths_and_uvs() {
        let camera = FreeFlightCamera {
            position: [10.0, 20.0, 30.0],
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: std::f32::consts::FRAC_PI_2,
            near_plane: 0.1,
            far_plane: 100.0,
            move_speed: 1.0,
            ground_clearance: 0.0,
        }
        .preview_frame(1.0);
        let screen = ScreenBillboard {
            world_head: [0.0; 3],
            world_tail: [0.0; 3],
            head: [0.0, 0.0],
            tail: [0.0, 0.0],
            corners: [[-0.25, -0.5], [0.25, -0.5], [-0.25, 0.5], [0.25, 0.5]],
            uv: [[0.1, 0.2], [0.3, 0.4], [0.5, 0.6], [0.7, 0.8]],
            half_size: 12.0,
            head_depth: 8.0,
            tail_depth: 4.0,
        };
        let vertices = precipitation_quad_vertices(
            PrecipitationKind::Rain,
            &screen,
            [1.0, 0.5, 0.25, 0.75],
            &camera,
            [100.0, 100.0],
        );
        assert_eq!(vertices[0].uv, screen.uv[0]);
        assert_eq!(vertices[3].uv, screen.uv[3]);
        assert!(
            (dot3(
                sub3(vertices[0].position, camera.position),
                camera.forward()
            ) - 4.0)
                .abs()
                < 1.0e-5
        );
        assert!(
            (dot3(
                sub3(vertices[3].position, camera.position),
                camera.forward()
            ) - 8.0)
                .abs()
                < 1.0e-5
        );
        assert_eq!(vertices[0].overlay_alpha, 0.75);
    }

    #[test]
    fn sprite_upload_remaps_native_left_top_uv_order_to_quad_positions() {
        let camera = FreeFlightCamera {
            position: [0.0; 3],
            yaw: 0.0,
            pitch: 0.0,
            horizontal_fov: 1.0,
            near_plane: 0.1,
            far_plane: 100.0,
            move_speed: 1.0,
            ground_clearance: 0.0,
        }
        .preview_frame(1.0);
        let uv = [[1.0, 2.0], [3.0, 4.0], [5.0, 6.0], [7.0, 8.0]];
        let vertices = sprite_quad_vertices_pixels(
            &camera,
            camera.forward(),
            10.0,
            1.0,
            1.0,
            [100.0, 100.0],
            [1.0; 3],
            1.0,
            uv,
        );
        assert_eq!(
            vertices.map(|vertex| vertex.uv),
            [uv[1], uv[2], uv[0], uv[3]]
        );
    }

    #[test]
    fn control_type4_basis_branches_preserve_anisotropic_owner_scale() {
        let owner_scale = [2.0, 3.0, 4.0];
        let equal = [
            control_point([0.0; 3], [1.0, 1.0, 0.0]),
            control_point([0.0; 3], [1.0, 1.0, 0.0]),
            control_point([0.0; 3], [1.0, 1.0, 0.0]),
        ];
        let equal_matrix =
            control_type4_local_matrix([&equal[0], &equal[1], &equal[2]], owner_scale).unwrap();
        assert_matrix_columns(
            equal_matrix,
            [
                [2.0, 3.0, 0.0],
                [-3.0, 2.0, 0.0],
                [0.0, 0.0, 13.0_f32.sqrt()],
            ],
        );

        let unique = [
            control_point([1.0; 3], [1.0, 2.0, 3.0]),
            control_point([2.0; 3], [4.0, 5.0, 6.0]),
            control_point([3.0; 3], [-1.0, 1.0, 2.0]),
        ];
        let unique_matrix =
            control_type4_local_matrix([&unique[0], &unique[1], &unique[2]], owner_scale).unwrap();
        assert_matrix_columns(
            unique_matrix,
            [[2.0, 6.0, 12.0], [8.0, 15.0, 24.0], [-2.0, 3.0, 8.0]],
        );
        assert_eq!(
            [
                unique_matrix[0][3],
                unique_matrix[1][3],
                unique_matrix[2][3]
            ],
            [4.0, 6.0, 8.0]
        );

        for (directions, expected) in [
            (
                [[1.0, 0.0, 0.0], [1.0, 0.0, 0.0], [0.0, 0.0, 1.0]],
                [[2.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 2.0]],
            ),
            (
                [[0.0, 0.0, 1.0], [1.0, 0.0, 0.0], [0.0, 0.0, 1.0]],
                [[0.0, 0.0, 4.0], [0.0, -1.0, 0.0], [4.0, 0.0, 0.0]],
            ),
            (
                [[0.0, 1.0, 0.0], [0.0, 0.0, 1.0], [0.0, 0.0, 1.0]],
                [[0.0, 3.0, 0.0], [-1.0, 0.0, 0.0], [0.0, 0.0, 3.0]],
            ),
            (
                [[1.0, 0.0, 0.0], [1.0, 0.0, 0.0], [2.0, 0.0, 0.0]],
                [[2.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 2.0]],
            ),
        ] {
            let repeated = directions.map(|direction| control_point([0.0; 3], direction));
            let matrix =
                control_type4_local_matrix([&repeated[0], &repeated[1], &repeated[2]], owner_scale)
                    .unwrap();
            assert_matrix_columns(matrix, expected);
        }
    }

    #[test]
    fn control_type4_world_matrix_rotates_basis_and_keeps_scale_off_translation() {
        let point = control_point([1.0, 0.0, 0.0], [1.0, 0.0, 0.0]);
        let local =
            control_type4_effect_local_matrix([&point, &point, &point], [2.0, 3.0, 4.0]).unwrap();
        let matrix = control_type4_world_from_effect(
            local,
            [2.0, 3.0, 4.0],
            LegacyIron3dEulerTransform {
                translation: [10.0, 20.0, 30.0],
                orientation_radians: [0.0, 0.0, std::f32::consts::FRAC_PI_2],
            },
            None,
            VulkanNodePose {
                translation: [0.0; 3],
                rotation: [0.0, 0.0, 0.0, 1.0],
            },
        )
        .unwrap();

        assert_matrix_columns(
            matrix,
            [[0.0, 4.0, 0.0], [-9.0, 0.0, 0.0], [0.0, 0.0, 16.0]],
        );
        for (actual, expected) in [matrix[0][3], matrix[1][3], matrix[2][3]]
            .into_iter()
            .zip([10.0, 22.0, 30.0])
        {
            assert!((actual - expected).abs() < 1.0e-5);
        }
    }

    #[test]
    fn mounted_control_effect_uses_component_pose_before_owner_world_transform() {
        let point = control_point([1.0, 0.0, 0.0], [1.0, 0.0, 0.0]);
        let mount_pose = VulkanNodePose {
            translation: [1.0, 2.0, 3.0],
            rotation: [
                0.0,
                0.0,
                std::f32::consts::FRAC_1_SQRT_2,
                std::f32::consts::FRAC_1_SQRT_2,
            ],
        };
        let owner_node_pose = VulkanNodePose {
            translation: [0.0; 3],
            rotation: [0.0, 0.0, 0.0, 1.0],
        };
        let local = control_type4_effect_local_matrix([&point, &point, &point], [1.0; 3]).unwrap();
        let matrix = control_type4_world_from_effect(
            local,
            [2.0, 3.0, 4.0],
            LegacyIron3dEulerTransform {
                translation: [10.0, 20.0, 30.0],
                orientation_radians: [0.0; 3],
            },
            Some(mount_pose),
            owner_node_pose,
        )
        .unwrap();

        for (actual, expected) in [matrix[0][3], matrix[1][3], matrix[2][3]]
            .into_iter()
            .zip([12.0, 29.0, 42.0])
        {
            assert!((actual - expected).abs() < 1.0e-5);
        }
    }

    #[test]
    fn plant_node23_control_points_match_captured_native_world_positions() {
        let root_transform = LegacyIron3dEulerTransform {
            translation: [323.55048, 806.97266, 0.36829287],
            orientation_radians: [0.0, 0.0, 1.6262363],
        };
        let owner_node_pose = VulkanNodePose {
            translation: [0.0, -68.15999, 21.12],
            rotation: [0.0, 0.0, 0.0, 1.0],
        };
        let points = [
            (
                [-12.964036, 12.991658, -21.119995],
                [379.35242, 797.0855, 0.3682986],
            ),
            (
                [13.49774, 12.991658, -21.119995],
                [377.8861, 823.5066, 0.3682986],
            ),
            (
                [9.507235, -3.006884, -21.119993],
                [394.08118, 820.40875, 0.3683005],
            ),
            (
                [-9.080112, -3.2843084, -21.119991],
                [395.38815, 801.86536, 0.3683024],
            ),
        ];

        for (local_position, expected_world) in points {
            let point = control_point(local_position, [1.0, 0.0, 0.0]);
            let local = control_type4_effect_local_matrix([&point, &point, &point], [1.0; 3])
                .expect("CPT descriptor local matrix");
            let world = control_type4_world_from_effect(
                local,
                [1.0; 3],
                root_transform,
                None,
                owner_node_pose,
            )
            .expect("attached Control owner matrix");
            for axis in 0..3 {
                assert!(
                    (world[axis][3] - expected_world[axis]).abs() < 0.1,
                    "axis {axis}: actual {} expected {}",
                    world[axis][3],
                    expected_world[axis]
                );
            }
        }
    }

    #[test]
    fn ambient_effect_world_refreshes_from_each_component_pose_buffer() {
        let mut poses = vec![fparkan_animation::Pose::default(); 24];
        poses[23].translation = [0.0, -68.15999, 21.12];
        let mut slot = AmbientEffectGpuSlot {
            kind: AmbientEffectKind::Op3Type2,
            time_mode: 1,
            header_flags: 0,
            random_instance_key: ControlEffectInstanceKey {
                object_index: 0,
                component_index: 0,
                table_index: 8,
                row_index: 6,
            },
            random_seed: 1,
            phase_jitter: 0.0,
            random_shift: [0.0; 3],
            owner_object_index: 0,
            owner_component_index: 0,
            owner_node_index: 23,
            owner_component_is_mounted: false,
            root_transform: LegacyIron3dEulerTransform {
                translation: [323.55048, 806.97266, 0.36829287],
                orientation_radians: [0.0, 0.0, 1.6262363],
            },
            owner_scale: [1.0; 3],
            mount_pose: None,
            local_from_effect: [
                [1.0, 0.0, 0.0, -12.964036],
                [0.0, 1.0, 0.0, 12.991658],
                [0.0, 0.0, 1.0, -21.119995],
                [0.0, 0.0, 0.0, 1.0],
            ],
            control_source: String::new(),
            control_table_index: 8,
            control_row_index: 6,
            control_point_indices: [104; 3],
            control_point_owners: [23; 3],
            command: endpoint_op3_command(),
            command_index: 0,
            duration_seconds: 1.0,
            world_from_effect: [[0.0; 4]; 4],
            range: EnvironmentGpuRange {
                range_index: 0,
                vertex_start: 0,
                vertex_capacity: 4,
                material_index: 0,
            },
            additional_particle_ranges: Vec::new(),
            material_animation_index: 0,
            additional_particle_material_animation_indices: Vec::new(),
            smoke_emitter_state: None,
            op7_emitter_state: None,
        };
        let mut component_pose_buffers = vec![vec![Some(NodePoseBuffer { poses })]];
        let first = ambient_effect_world_from_component_pose(&slot, &component_pose_buffers)
            .expect("first sampled owner pose");
        assert!((first[0][3] - 379.35242).abs() < 0.1 && (first[1][3] - 797.0855).abs() < 0.1);

        let pose = &mut component_pose_buffers[0][0].as_mut().unwrap().poses[23];
        pose.translation = [
            pose.translation[0] + 1.0,
            pose.translation[1] + 2.0,
            pose.translation[2] + 3.0,
        ];
        let second = ambient_effect_world_from_component_pose(&slot, &component_pose_buffers)
            .expect("next sampled owner pose");
        slot.world_from_effect = second;
        assert_ne!(first, slot.world_from_effect);
        let expected_delta = rotate_unit_vector(
            [1.0, 2.0, 3.0],
            [
                0.0,
                0.0,
                (1.6262363_f32 * 0.5).sin(),
                (1.6262363_f32 * 0.5).cos(),
            ],
        );
        for (axis, expected) in expected_delta.into_iter().enumerate() {
            let delta = slot.world_from_effect[axis][3] - first[axis][3];
            assert!((delta - expected).abs() < 0.1, "axis {axis}: {delta}");
        }
    }

    #[test]
    fn mode1_control_effects_hold_active_with_full_opacity_after_duration() {
        let phase = native_command_phase(
            0,
            ambient_effect_phase(1, 0, 1.25, 1.0).expect("mode 1 phase"),
            0.0,
        );
        assert_eq!(phase, 1.0);
        let identity = [
            [1.0, 0.0, 0.0, 0.0],
            [0.0, 1.0, 0.0, 0.0],
            [0.0, 0.0, 1.0, 0.0],
            [0.0, 0.0, 0.0, 1.0],
        ];

        let lamp =
            evaluate_op3_type2_command(&endpoint_op3_command(), 0, &identity, 1.25, phase, 0)
                .expect("lamp endpoint");
        assert!(lamp.active);
        assert_eq!(lamp.color[3], 1.0);

        let op9 = endpoint_gener_ball_command(FxOpcode::Op9);
        let generated = evaluate_f_gener_ball_mesh(
            &op9,
            0,
            &identity,
            phase,
            1.25,
            [0.0, 0.0, 500.0],
            AMBIENT_EFFECT_NATIVE_CATEGORY,
        )
        .expect("generator sphere endpoint");
        assert!(generated.active);
        assert_eq!(generated.color[3], 1.0);
        assert_eq!(generated.vertices.len(), 88);
        assert_eq!(generated.indices.len(), 120);
        assert_eq!(generated.native_category, 0);

        let op4 = endpoint_gener_ball_command(FxOpcode::Op4);
        let orb = evaluate_f_gener_ball(&op4, 0, &identity, phase, 1.25, [0.0, 0.0, 500.0])
            .expect("opcode 4 billboard endpoint");
        assert!(orb.active);
        assert_eq!(orb.color[3], 1.0);
    }

    #[test]
    fn op9_mesh_bridge_allocates_one_range_per_quad_and_cap() {
        let command = endpoint_gener_ball_command(FxOpcode::Op9);
        let identity = [
            [1.0, 0.0, 0.0, 0.0],
            [0.0, 1.0, 0.0, 0.0],
            [0.0, 0.0, 1.0, 0.0],
            [0.0, 0.0, 0.0, 1.0],
        ];
        let frame = evaluate_f_gener_ball_mesh(
            &command,
            0,
            &identity,
            0.5,
            0.5,
            [0.0, 0.0, 500.0],
            AMBIENT_EFFECT_NATIVE_CATEGORY,
        )
        .expect("category-zero Op9 mesh");
        let primitives = ambient_effect_mesh_primitive_layout(&frame)
            .expect("native Op9 quad/cap primitive layout");
        assert_eq!(primitives.len(), 24);
        assert_eq!(
            primitives
                .iter()
                .filter(|item| item.vertex_count == 4)
                .count(),
            16
        );
        assert_eq!(
            primitives
                .iter()
                .filter(|item| item.vertex_count == 3)
                .count(),
            8
        );

        let mut mesh = VulkanStaticMesh {
            vertices: Vec::new(),
            indices: Vec::new(),
            draw_ranges: Vec::new(),
        };
        let ranges = primitives
            .iter()
            .copied()
            .map(|primitive| {
                let range = append_environment_range(
                    &mut mesh,
                    0,
                    ambient_effect_mesh_primitive_vertices(&frame, primitive),
                    ambient_effect_mesh_primitive_indices(&frame, primitive)
                        .expect("primitive-local indices"),
                    LegacyPipelineState::default(),
                )
                .expect("allocate one native primitive range");
                write_ambient_effect_mesh_primitive(&mut mesh, &range, &frame, primitive)
                    .expect("write native primitive frame");
                range
            })
            .collect::<Vec<_>>();

        assert_eq!(ranges.len(), 24);
        assert_eq!(mesh.draw_ranges.len(), 24);
        assert_eq!(mesh.indices.len(), 120);
        assert!(mesh.draw_ranges.iter().all(|range| {
            range.alpha_test_reference == VulkanStaticDrawRange::NATIVE_DEFAULT_ALPHA_TEST_REFERENCE
        }));
        assert_eq!(
            mesh.draw_ranges
                .iter()
                .map(|range| range.index_count)
                .sum::<u32>(),
            120
        );
        for (range, primitive) in ranges.iter().zip(primitives) {
            let vertices =
                &mesh.vertices[range.vertex_start..range.vertex_start + range.vertex_capacity];
            assert_eq!(range.vertex_capacity, primitive.vertex_count);
            for (offset, vertex) in vertices.iter().enumerate() {
                assert_eq!(
                    vertex.position,
                    frame.vertices[primitive.vertex_start + offset]
                );
                assert_eq!(vertex.uv, frame.uv[primitive.vertex_start + offset]);
                assert_eq!(vertex.overlay_alpha, frame.color[3]);
            }
            let range_indices = &mesh.draw_ranges[range.range_index];
            assert_eq!(range_indices.index_count as usize, primitive.index_count);
            let first_index = range_indices.first_index as usize;
            assert_eq!(
                mesh.indices[first_index],
                u32::try_from(range.vertex_start).unwrap()
            );
            let camera = [10.0, -5.0, 2.0];
            let expected = sub3(frame.vertices[primitive.vertex_start], camera);
            let expected = dot3(expected, expected).sqrt();
            let actual = first_indexed_vertex_distance(&mesh, range.range_index, camera)
                .expect("native Op9 primitive distance key");
            assert!((actual - expected).abs() < 1e-5);
        }

        for selector in [1, 2] {
            let mut command = command.clone();
            write_effect_u32(Arc::make_mut(&mut command.raw_body), 0xC4, selector);
            let frame = evaluate_f_gener_ball_mesh(
                &command,
                0,
                &identity,
                0.5,
                0.5,
                [0.0, 0.0, 500.0],
                AMBIENT_EFFECT_NATIVE_CATEGORY,
            )
            .expect("Op9 selector frame");
            assert!(!ambient_effect_mesh_primitive_layout(&frame)
                .expect("selector native quad/cap layout")
                .is_empty());
        }
    }

    #[test]
    fn mode2_control_effects_repeat_and_reset_at_header_duration() {
        assert_eq!(ambient_effect_phase(2, 0, 1.0, 2.0), Some(0.5));
        assert_eq!(ambient_effect_phase(2, 0, 2.0, 2.0), Some(0.0));
        assert_eq!(ambient_effect_phase(2, 0, 2.25, 2.0), Some(0.125));
        assert_eq!(ambient_effect_phase(1, 0, 2.0, 2.0), Some(1.0));
        assert_eq!(ambient_effect_phase(0, 0, 0.5, 0.0), Some(0.0));
        assert_eq!(ambient_effect_phase(3, 0, 0.5, 2.0), None);
        assert_eq!(ambient_effect_phase(2, 0x20, 0.5, 1.0), Some(1.0));
        assert_eq!(ambient_effect_phase(2, 0x20, 0.75, 1.0), Some(0.5));
        assert_eq!(ambient_effect_phase(1, 0x200, 0.5, 1.0), Some(0.25));
        assert_eq!(ambient_effect_phase(1, 0x220, 0.5, 1.0), Some(0.5));
        assert_eq!(ambient_effect_phase(1, 0x220, 1.5, 1.0), Some(-2.5));
        assert_eq!(ambient_effect_phase(1, 0x20, 1.5, 1.0), Some(-1.0));
    }

    #[test]
    fn control_lamp_accepts_only_supported_bodies_and_keeps_mat0_state() {
        assert_eq!(
            ambient_effect_command_kind(&endpoint_op3_command()),
            Some(AmbientEffectKind::Op3Type2)
        );
        let mut type0 = endpoint_op3_command();
        write_effect_u32(Arc::make_mut(&mut type0.raw_body), 0, 0);
        assert_eq!(
            ambient_effect_command_kind(&type0),
            Some(AmbientEffectKind::Op3Type0)
        );
        assert!(ambient_effect_render_selector_allows_header(0x10, 0));
        assert!(!ambient_effect_render_selector_allows_header(0x800, 0));
        assert!(!ambient_effect_render_selector_allows_header(0xD00, 0));
        assert!(ambient_effect_render_selector_allows_header(0xD00, 1));
        assert!(ambient_effect_render_selector_allows_header(0xD00, 2));
        for opcode in [FxOpcode::Op9, FxOpcode::Op4] {
            assert_eq!(
                ambient_effect_command_kind(&endpoint_gener_ball_command(opcode)),
                Some(AmbientEffectKind::GenerBall),
                "{opcode:?}"
            );
        }
        for selector in [1, 2] {
            let mut op9 = endpoint_gener_ball_command(FxOpcode::Op9);
            write_effect_u32(Arc::make_mut(&mut op9.raw_body), 0xC4, selector);
            assert_eq!(
                ambient_effect_command_kind(&op9),
                Some(AmbientEffectKind::GenerBall),
                "Op9 selector {selector}"
            );
        }
        let mut invalid_op9 = endpoint_gener_ball_command(FxOpcode::Op9);
        write_effect_u32(Arc::make_mut(&mut invalid_op9.raw_body), 0xC4, 3);
        assert_eq!(ambient_effect_command_kind(&invalid_op9), None);
        assert_eq!(
            ambient_effect_command_kind(&endpoint_op8_command(6)),
            Some(AmbientEffectKind::SmokePool)
        );
        for pool_count in [0, 4097] {
            assert_eq!(
                ambient_effect_command_kind(&endpoint_op8_command(pool_count)),
                None
            );
        }
        for raw_mode in [0, 1] {
            let op7 = endpoint_op7_command(raw_mode, 1.5, 0.0, 3, 2);
            assert_eq!(
                ambient_effect_command_kind(&op7),
                Some(AmbientEffectKind::Op7ParticlePool),
                "raw mode {raw_mode}"
            );
            assert_eq!(ambient_effect_op7_range_capacity(&op7), Some(6));
        }
        let accelerated_op7 = endpoint_op7_command(1, 1.5, 0.25, 3, 2);
        assert_eq!(
            ambient_effect_command_kind(&accelerated_op7),
            Some(AmbientEffectKind::Op7ParticlePool)
        );
        assert_eq!(ambient_effect_op7_range_capacity(&accelerated_op7), Some(6));
        for unsupported in [
            endpoint_op7_command(2, 1.5, 0.0, 3, 2),
            endpoint_op7_command(0, 1.5, f32::NAN, 3, 2),
            endpoint_op7_command(0, 0.0, 0.0, 3, 2),
            endpoint_op7_command(0, f32::NAN, 0.0, 3, 2),
            endpoint_op7_command(0, 1.5, 0.0, u32::MAX, 2),
        ] {
            assert_eq!(ambient_effect_command_kind(&unsupported), None);
        }

        let state = ambient_effect_pipeline_state(2).expect("native additive MAT0 category");
        assert_eq!(state.blend, LegacyBlendMode::Additive);
        assert!(state.alpha_test);
        assert_eq!(state.depth, LegacyDepthMode::TestReadOnly);
    }

    #[test]
    fn op1_control_lights_use_native_phase_owner_transform_and_flags() {
        let mut slot = ControlPointLightSlot {
            time_mode: 1,
            header_flags: 0,
            random_instance_key: ControlEffectInstanceKey {
                object_index: 0,
                component_index: 0,
                table_index: 0,
                row_index: 0,
            },
            random_seed: 1,
            phase_jitter: 0.0,
            random_shift: [0.0; 3],
            duration_seconds: 1.0,
            owner_object_index: 0,
            owner_component_index: 0,
            owner_node_index: 0,
            owner_component_is_mounted: false,
            root_transform: LegacyIron3dEulerTransform {
                translation: [10.0, 20.0, 30.0],
                orientation_radians: [0.0; 3],
            },
            owner_scale: [1.0; 3],
            mount_pose: None,
            local_from_effect: [
                [1.0, 0.0, 0.0, 1.0],
                [0.0, 1.0, 0.0, 2.0],
                [0.0, 0.0, 1.0, 3.0],
                [0.0, 0.0, 0.0, 1.0],
            ],
            world_from_effect: [[0.0; 4]; 4],
            command_index: 0,
            command: endpoint_op1_command(6, 0.5, 1.0),
        };
        let poses = vec![vec![None]];
        let mounts = vec![vec![None]];

        let inactive = slot.clone();
        let random_samples = HashMap::new();
        assert!(update_control_point_lights(
            &mut [inactive],
            &poses,
            &mounts,
            0.25,
            &random_samples,
            false,
        )
        .is_empty());
        let lights = update_control_point_lights(
            std::slice::from_mut(&mut slot),
            &poses,
            &mounts,
            0.75,
            &random_samples,
            false,
        );
        assert_eq!(lights.len(), 1);
        let (light, flags) = lights[0];
        assert_eq!(light.position, [13.0, 22.0, 33.0]);
        assert_eq!(light.rgb, [0.25, 0.5, 0.75]);
        assert_eq!(light.range, 15.0);
        assert_eq!(light.coefficients, [1.0, 0.5, 0.25]);
        assert_eq!(flags, 0xA000_0000);
        assert_eq!(
            [
                slot.world_from_effect[0][3],
                slot.world_from_effect[1][3],
                slot.world_from_effect[2][3]
            ],
            [11.0, 22.0, 33.0]
        );

        slot.header_flags = 0x29;
        slot.random_seed = 0x1234_5678;
        slot.phase_jitter = 0.4;
        slot.random_shift = [2.0, 4.0, 6.0];
        let sibling_slots = [slot.clone(), slot.clone()];
        let mut states = HashMap::new();
        let first = advance_control_effect_random_states(
            &mut states,
            &[],
            &sibling_slots,
            SceneSampleId::Replay(7),
            150,
            1.5,
        );
        assert_eq!(first.len(), 1);
        let key = slot.random_instance_key;
        let first_sample = first[&key];
        assert_eq!(first_sample.phase_jitter, 0.0, "the -1 phase skips jitter");
        assert_ne!(first_sample.accumulated_shift, [0.0; 3]);
        let mut expected_state = ControlEffectRandomState::new(
            slot.random_seed,
            slot.header_flags,
            slot.phase_jitter,
            slot.random_shift,
        );
        assert_eq!(
            first_sample,
            expected_state.advance(SceneSampleId::Replay(7), 150, -1.0)
        );
        assert_eq!(
            advance_control_effect_random_states(
                &mut states,
                &[],
                &sibling_slots,
                SceneSampleId::Replay(7),
                150,
                1.5,
            )[&key],
            first_sample,
            "a repeated read of the same captured update reuses the shared sample"
        );
        let second = advance_control_effect_random_states(
            &mut states,
            &[],
            &sibling_slots,
            SceneSampleId::Replay(8),
            200,
            0.5,
        );
        assert_eq!(
            second[&key],
            expected_state.advance(SceneSampleId::Replay(8), 200, 1.0)
        );
        assert_ne!(second[&key].phase_jitter, first_sample.phase_jitter);
        assert_ne!(
            second[&key].accumulated_shift,
            first_sample.accumulated_shift
        );
        assert_eq!(states[&key].last_update_clock_ms, Some(200));

        let negative_non_sentinel =
            ambient_effect_phase(1, 0x220, 1.5, 1.0).expect("post-duration transformed phase");
        assert_eq!(negative_non_sentinel, -2.5);
        let mut negative_state = ControlEffectRandomState::new(
            slot.random_seed,
            0x229,
            slot.phase_jitter,
            slot.random_shift,
        );
        assert_eq!(
            native_command_phase(0x229, negative_non_sentinel, 0.4),
            0.0,
            "a phase below -1 clamps to zero rather than using the -1 sentinel"
        );
        assert_ne!(
            negative_state
                .advance(SceneSampleId::Live(1), 150, negative_non_sentinel)
                .phase_jitter,
            0.0,
            "a non-sentinel negative phase still consumes the jitter sample"
        );
    }

    #[test]
    fn op1_generic_diffuse_list_excludes_bit31_and_clears_inactive_lights() {
        let light = |position, active| VulkanPointLight {
            position,
            rgb: [0.25, 0.5, 0.75],
            range: 15.0,
            coefficients: [1.0, 0.5, 0.25],
            active,
        };
        let raw_records = vec![
            (light([1.0, 2.0, 3.0], true), 0xA000_0000),
            (light([4.0, 5.0, 6.0], true), 0x2000_0000),
            (light([7.0, 8.0, 9.0], true), 0x8000_0000),
            (light([10.0, 11.0, 12.0], false), 0x0000_0000),
        ];

        let ordinary = ordinary_control_point_lights(&raw_records);
        assert_eq!(ordinary.len(), 1);
        assert_eq!(ordinary[0].position, [4.0, 5.0, 6.0]);
        assert_eq!(raw_records.len(), 4);
        assert_eq!(
            raw_records
                .iter()
                .map(|(_, flags)| *flags)
                .collect::<Vec<_>>(),
            vec![0xA000_0000, 0x2000_0000, 0x8000_0000, 0]
        );

        assert!(ordinary_control_point_lights(&[]).is_empty());
        assert!(
            ordinary_control_point_lights(&[(light([13.0, 14.0, 15.0], false), 0x2000_0000)])
                .is_empty()
        );
    }

    #[test]
    fn op1_control_slot_accepts_supported_bodies_with_instance_random_flags() {
        let command = endpoint_op1_command(6, 0.0, 1.0);
        assert!(ambient_effect_op1_supported(&command));
        assert!(!ambient_effect_op1_supported(&endpoint_op1_command(
            4, 0.0, 1.0
        )));
    }

    #[test]
    fn op1_phase_preserves_native_sentinel_and_initial_manager_gate() {
        assert_eq!(native_command_phase(0, -1.0, 0.4), -1.0);
        assert_eq!(native_command_phase(0x100, 0.625, 0.0), 0.625);
        assert_eq!(native_command_phase(0x80, 0.625, 0.4), 0.0);
        assert_eq!(native_command_phase(0x81, -1.0, 0.4), 0.4);
        assert_eq!(native_command_phase(0, -0.25, 0.0), 0.0);
        assert_eq!(native_command_phase(0, 1.25, 0.0), 1.0);
        assert_eq!(native_command_phase(1, 0.5, 0.25), 0.75);
        assert_eq!(native_command_phase(1, 0.9, 0.25), 1.0);
        let flags_200_20 =
            ambient_effect_phase(1, 0x220, 1.5, 1.0).expect("triangular post-duration phase");
        assert_eq!(flags_200_20, -2.5);
        assert_eq!(native_command_phase(0x220, flags_200_20, 0.4), 0.0);
        let raw_minus_one =
            ambient_effect_phase(1, 0x20, 1.5, 1.0).expect("triangular sentinel phase");
        assert_eq!(raw_minus_one, -1.0);
        assert_eq!(native_command_phase(0x21, raw_minus_one, 0.4), -1.0);
        assert_eq!(native_command_phase(0xA1, raw_minus_one, 0.4), 0.4);
    }

    #[test]
    fn op7_variable_frames_clear_inactive_draw_ranges() {
        let aligned = align_ambient_effect_frames(
            vec![endpoint_effect_frame(3), endpoint_effect_frame(7)],
            4,
            true,
        )
        .expect("variable Op7 output fits its fixed range allocation");
        assert_eq!(aligned.len(), 4);
        assert_eq!(
            aligned[0].as_ref().map(|frame| frame.command_index),
            Some(3)
        );
        assert_eq!(
            aligned[1].as_ref().map(|frame| frame.command_index),
            Some(7)
        );
        assert!(aligned[2].is_none() && aligned[3].is_none());

        assert!(align_ambient_effect_frames(vec![endpoint_effect_frame(0)], 4, false,).is_err());
        assert!(align_ambient_effect_frames(vec![endpoint_effect_frame(0); 5], 4, true,).is_err());
    }

    #[test]
    fn active_control_fx_vertex_color_uses_sampled_mat0_additive_rgb() {
        let mut slot = AmbientEffectGpuSlot {
            kind: AmbientEffectKind::Op3Type2,
            time_mode: 1,
            header_flags: 0,
            random_instance_key: ControlEffectInstanceKey {
                object_index: 0,
                component_index: 0,
                table_index: 0,
                row_index: 0,
            },
            random_seed: 1,
            phase_jitter: 0.0,
            random_shift: [0.0; 3],
            owner_object_index: 0,
            owner_component_index: 0,
            owner_node_index: 0,
            owner_component_is_mounted: false,
            root_transform: LegacyIron3dEulerTransform {
                translation: [0.0; 3],
                orientation_radians: [0.0; 3],
            },
            owner_scale: [1.0; 3],
            mount_pose: None,
            local_from_effect: [
                [1.0, 0.0, 0.0, 0.0],
                [0.0, 1.0, 0.0, 0.0],
                [0.0, 0.0, 1.0, 0.0],
                [0.0, 0.0, 0.0, 1.0],
            ],
            control_source: String::new(),
            control_table_index: 0,
            control_row_index: 0,
            control_point_indices: [0; 3],
            control_point_owners: [0; 3],
            command: endpoint_op3_command(),
            command_index: 0,
            duration_seconds: 1.0,
            world_from_effect: [
                [1.0, 0.0, 0.0, 0.0],
                [0.0, 1.0, 0.0, 0.0],
                [0.0, 0.0, 1.0, 0.0],
                [0.0, 0.0, 0.0, 1.0],
            ],
            range: EnvironmentGpuRange {
                range_index: 0,
                vertex_start: 0,
                vertex_capacity: 4,
                material_index: 0,
            },
            additional_particle_ranges: vec![EnvironmentGpuRange {
                range_index: 1,
                vertex_start: 4,
                vertex_capacity: 4,
                material_index: 1,
            }],
            material_animation_index: 0,
            additional_particle_material_animation_indices: vec![1],
            smoke_emitter_state: None,
            op7_emitter_state: None,
        };
        assert_eq!(
            ambient_effect_ranges(&slot)
                .iter()
                .map(|(range, binding)| (range.range_index, *binding))
                .collect::<Vec<_>>(),
            vec![(0, 0), (1, 1)]
        );
        let mut mesh = VulkanStaticMesh {
            vertices: vec![environment_vertex([0.0; 3], [1.0; 3], [0.0; 2]); 8],
            indices: Vec::new(),
            draw_ranges: Vec::new(),
        };
        let updates = [
            AmbientEffectGeometryUpdate {
                range_index: 0,
                index_count: 6,
                command_rgb: [1.0; 3],
            },
            AmbientEffectGeometryUpdate {
                range_index: 1,
                index_count: 6,
                command_rgb: [1.0; 3],
            },
        ];
        let mut active_materials = HashMap::from([
            (
                0,
                ActiveMaterialState {
                    material_index: 0,
                    phase_index: 0,
                    diffuse_alpha: 1.0,
                    additive_rgb: [0.9882353, 1.0, 0.16862746],
                },
            ),
            (
                1,
                ActiveMaterialState {
                    material_index: 1,
                    phase_index: 0,
                    diffuse_alpha: 1.0,
                    additive_rgb: [0.9882353, 1.0, 0.16862746],
                },
            ),
        ]);

        apply_ambient_effect_material_tints(
            &[slot.clone()],
            &mut mesh,
            &updates,
            &active_materials,
        )
        .expect("apply sampled yellow MAT0 color");
        assert!(mesh
            .vertices
            .iter()
            .all(|vertex| vertex.color == [0.9882353, 1.0, 0.16862746]));

        for material in active_materials.values_mut() {
            material.additive_rgb = [0.1, 0.7, 0.2];
        }
        slot.kind = AmbientEffectKind::SmokePool;
        apply_ambient_effect_material_tints(&[slot], &mut mesh, &updates, &active_materials)
            .expect("apply next sampled MAT0 color");
        assert!(mesh
            .vertices
            .iter()
            .all(|vertex| vertex.color == [0.1, 0.7, 0.2]));
    }

    #[test]
    fn ambient_fx_uses_vertex_opacity_without_multiplying_mat0_opacity() {
        let mat0_opacity = ambient_effect_material_alpha(true, 0.4);
        let effect_opacity = 0.5;
        let texture_alpha = 0.25;
        assert_eq!(mat0_opacity, 1.0);
        assert_eq!(mat0_opacity * effect_opacity, 0.5);
        assert_eq!(texture_alpha * mat0_opacity * effect_opacity, 0.125);
        assert_eq!(ambient_effect_material_alpha(false, 0.4), 0.4);
    }

    #[test]
    fn material_animation_cpu_packet_uses_sampled_phase_without_renderer() {
        let phase = |additive_red| MaterialPhase {
            parameters: [
                additive_red,
                0,
                0,
                100,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
                0,
            ],
            texture_raw: [0; 16],
        };
        let document = Mat0Document {
            version: 0,
            animation_block_count: 1,
            phases: vec![phase(0), phase(255)],
            prefix: Vec::new(),
            header_opaque: [0; 2],
            animation_blocks: vec![MaterialAnimationBlock {
                header_raw: 0,
                keys: vec![
                    MaterialKey {
                        k0: 0,
                        k1: 500,
                        k2: 0,
                    },
                    MaterialKey {
                        k0: 1,
                        k1: 1000,
                        k2: 0,
                    },
                ],
                bytes: Vec::new(),
            }],
        };
        let mut binding = MaterialAnimationBinding {
            initial_phase_index: 0,
            normalized_phase_override: Some(0.75),
            ambient_fx_material_alpha: true,
            variants: Vec::new(),
            base: MaterialPhaseBinding {
                document,
                animation_block_index: 0,
                wear_row_start_ms: 0,
                random_state: 0,
                frozen_phase_index: None,
                phase_uv_transforms: vec![[0.0, 0.0, 1.0, 1.0]; 2],
            },
            detail: None,
            overlay: None,
            overlay_detail: None,
            stage_textures: None,
        };

        let effect_sample = sample_material_animation_base(&mut binding, 0)
            .expect("sample the effect's native normalized MAT0 phase");
        assert_eq!(effect_sample.phase_index, 1);
        assert_eq!(effect_sample.coefficients.additive_rgb, [1.0, 0.0, 0.0]);

        binding.normalized_phase_override = None;
        let world_sample = sample_material_animation_base(&mut binding, 0)
            .expect("sample ordinary clock-driven material phase");
        assert_eq!(world_sample.phase_index, 0);
        assert_eq!(world_sample.coefficients.additive_rgb, [0.0, 0.0, 0.0]);

        binding.variants.push(MaterialVariantSet {
            phase_material_indices: vec![0, 0],
            range_indices: vec![7],
            pipeline_category: 0,
        });
        let mut materials = Vec::new();
        append_environment_gradient_material(&mut materials)
            .expect("prepare test material without a renderer");
        let update =
            sample_material_animations(std::slice::from_mut(&mut binding), &materials, 500)
                .expect("produce a CPU material-frame packet without a renderer");
        assert_eq!(update.active_materials[&7].material_index, 0);
        assert_eq!(update.active_materials[&7].phase_index, 1);
        assert_eq!(update.range_selections[0].range_index, 7);
    }

    #[test]
    fn ambient_fx_tint_requires_a_proven_ambient_mat0_phase() {
        assert!(ambient_effect_tint_supported(
            &[false, false],
            &[[0.0; 3], [0.2; 3]],
            &[[1.0, 1.0, 1.0], [0.2, 0.4, 0.8]],
        ));
        assert!(!ambient_effect_tint_supported(&[], &[], &[]));
        assert!(!ambient_effect_tint_supported(&[false], &[], &[]));
        assert!(!ambient_effect_tint_supported(
            &[true],
            &[[0.0; 3]],
            &[[1.0; 3]]
        ));
        assert!(!ambient_effect_tint_supported(
            &[false],
            &[[0.1, 0.0, 0.0]],
            &[[0.0; 3]],
        ));
        assert!(!ambient_effect_tint_supported(
            &[false],
            &[[0.0; 3]],
            &[[f32::NAN, 1.0, 1.0]]
        ));
    }

    #[test]
    fn ambient_fx_ranges_are_excluded_from_world_alpha_and_count_updates() {
        let fixed_ranges = HashSet::from([1, 4, 7]);
        let world_ranges = world_draw_range_indices(9, &fixed_ranges);
        assert_eq!(world_ranges, vec![0, 2, 3, 5, 6, 8]);
        assert!(!world_ranges.contains(&7));
    }

    #[test]
    fn ambient_control_rows_accept_unconditional_low_words_but_skip_state_gates_and_chains() {
        let mut row = PreparedControlEffectRow {
            table_index: 2,
            row_index: 0,
            raw_condition: [0, 7, 9],
            point_offsets: [0, 1, 2],
            selector: 0,
            resource: fparkan_assets::PreparedControlResourcePair {
                archive: [0; 32],
                name: [0; 32],
            },
        };
        assert!(ambient_effect_row_unconditionally_active(&row));
        for condition_flag in [0x1000_0000, 0x2000_0000, 0x4000_0000, 0x8000_0000] {
            row.raw_condition[0] = condition_flag;
            assert!(!ambient_effect_row_unconditionally_active(&row));
        }
    }
}