fix(vulkan-policy): gate requested depth formats

8 files changed, 234 insertions, 31 deletions

diff --git a/adapters/fparkan-render-vulkan/src/ffi.rs b/adapters/fparkan-render-vulkan/src/ffi.rs
index ece45e0..386cb68 100644
--- a/adapters/fparkan-render-vulkan/src/ffi.rs
+++ b/adapters/fparkan-render-vulkan/src/ffi.rs
@@ -38,7 +38,8 @@ mod swapchain_resources;
 mod validation;
 
 pub use self::capabilities::{
-    probe_vulkan_runtime_capabilities, VulkanRuntimeCapabilityError, VulkanRuntimeCapabilityProbe,
+    probe_vulkan_runtime_capabilities, probe_vulkan_runtime_capabilities_for_request,
+    VulkanRuntimeCapabilityError, VulkanRuntimeCapabilityProbe,
 };
 pub use self::instance::{
     create_vulkan_instance_probe, plan_vulkan_instance, probe_vulkan_loader,
@@ -54,8 +55,8 @@ use self::resources::{
     VulkanFrameSync,
 };
 pub use self::runtime::{
-    create_vulkan_logical_device_probe, VulkanLogicalDeviceError, VulkanLogicalDeviceProbe,
-    VulkanLogicalDeviceReport,
+    create_vulkan_logical_device_probe, create_vulkan_logical_device_probe_for_request,
+    VulkanLogicalDeviceError, VulkanLogicalDeviceProbe, VulkanLogicalDeviceReport,
 };
 pub use self::smoke_types::{
     VulkanSmokeBootstrapProgress, VulkanSmokeBootstrapSnapshot, VulkanSmokeFrameOutcome,
diff --git a/adapters/fparkan-render-vulkan/src/ffi/capabilities.rs b/adapters/fparkan-render-vulkan/src/ffi/capabilities.rs
index 94fb3a6..c0de225 100644
--- a/adapters/fparkan-render-vulkan/src/ffi/capabilities.rs
+++ b/adapters/fparkan-render-vulkan/src/ffi/capabilities.rs
@@ -1,11 +1,12 @@
 #![allow(unsafe_code)]
 
 use ash::vk;
+use fparkan_platform::RenderRequest;
 use std::ffi::CStr;
 
 use super::{VulkanInstanceProbe, VulkanSurfaceProbe};
 use crate::policy::{
-    compare_reports, plan_vulkan_swapchain, validate_device, VulkanCapabilityError,
+    compare_reports, plan_vulkan_swapchain, validate_device_for_request, VulkanCapabilityError,
     VulkanCapabilityReport, VulkanDeviceType, VulkanPhysicalDeviceRecord, VulkanQueueFamily,
     VulkanSurfaceFormat, VulkanSwapchainError, VulkanSwapchainPlan, VulkanSwapchainRequest,
     VulkanSwapchainSurfaceCapabilities,
@@ -133,14 +134,42 @@ pub fn probe_vulkan_runtime_capabilities(
     surface: &VulkanSurfaceProbe,
     drawable_extent: (u32, u32),
 ) -> Result<VulkanRuntimeCapabilityProbe, VulkanRuntimeCapabilityError> {
-    let selected = select_live_device_candidate(instance, surface, drawable_extent)?;
+    let selected = select_live_device_candidate_for_request(
+        instance,
+        surface,
+        drawable_extent,
+        &RenderRequest::conservative(),
+    )?;
+    Ok(selected.runtime)
+}
+
+/// Probes live Vulkan device, queue, surface and swapchain capabilities for a
+/// specific Stage 0 render request.
+///
+/// # Errors
+///
+/// Returns [`VulkanRuntimeCapabilityError`] when device enumeration, surface
+/// capability queries, Stage 0 device selection, or swapchain planning fails.
+pub fn probe_vulkan_runtime_capabilities_for_request(
+    instance: &VulkanInstanceProbe,
+    surface: &VulkanSurfaceProbe,
+    drawable_extent: (u32, u32),
+    render_request: &RenderRequest,
+) -> Result<VulkanRuntimeCapabilityProbe, VulkanRuntimeCapabilityError> {
+    let selected = select_live_device_candidate_for_request(
+        instance,
+        surface,
+        drawable_extent,
+        render_request,
+    )?;
     Ok(selected.runtime)
 }
 
-pub(super) fn select_live_device_candidate(
+pub(super) fn select_live_device_candidate_for_request(
     instance: &VulkanInstanceProbe,
     surface: &VulkanSurfaceProbe,
     drawable_extent: (u32, u32),
+    render_request: &RenderRequest,
 ) -> Result<SelectedLiveDevice, VulkanRuntimeCapabilityError> {
     let devices = {
         // SAFETY: The Vulkan instance is live for this query and no handles are retained.
@@ -151,13 +180,14 @@ pub(super) fn select_live_device_candidate(
     let mut best: Option<LiveDeviceCandidate> = None;
     let mut last_error = None;
     for (index, device) in devices.iter().copied().enumerate() {
-        let candidate = match live_device_candidate(instance, surface, device, index) {
-            Ok(candidate) => candidate,
-            Err(err) => {
-                last_error = Some(err);
-                continue;
-            }
-        };
+        let candidate =
+            match live_device_candidate(instance, surface, device, index, render_request) {
+                Ok(candidate) => candidate,
+                Err(err) => {
+                    last_error = Some(err);
+                    continue;
+                }
+            };
         match &best {
             Some(existing)
                 if compare_reports(&candidate.capability, &existing.capability)
@@ -192,6 +222,7 @@ fn live_device_candidate(
     surface: &VulkanSurfaceProbe,
     device: vk::PhysicalDevice,
     index: usize,
+    render_request: &RenderRequest,
 ) -> Result<LiveDeviceCandidate, VulkanRuntimeCapabilityError> {
     let properties = {
         // SAFETY: `device` was returned by this live instance and the result is copied by value.
@@ -210,6 +241,7 @@ fn live_device_candidate(
     let surface_formats = live_surface_formats(surface, device, &name)?;
     let present_modes = live_present_modes(surface, device, &name)?;
     let surface_capabilities = live_surface_capabilities(surface, device, &name)?;
+    let supported_depth_stencil_formats = live_depth_stencil_formats(instance, device);
     let queue_families = queue_properties
         .iter()
         .enumerate()
@@ -251,8 +283,10 @@ fn live_device_candidate(
         surface_formats: surface_formats.clone(),
         present_modes: present_modes.clone(),
         surface_capabilities,
+        supported_depth_stencil_formats,
     };
-    let capability = validate_device(&record).map_err(VulkanRuntimeCapabilityError::Capability)?;
+    let capability = validate_device_for_request(&record, render_request)
+        .map_err(VulkanRuntimeCapabilityError::Capability)?;
     Ok(LiveDeviceCandidate {
         physical_device: device,
         capability,
@@ -403,3 +437,34 @@ pub(super) fn live_surface_capabilities(
         supported_usage_flags: capabilities.supported_usage_flags.as_raw(),
     })
 }
+
+fn live_depth_stencil_formats(
+    instance: &VulkanInstanceProbe,
+    device: vk::PhysicalDevice,
+) -> Vec<i32> {
+    [
+        vk::Format::D16_UNORM,
+        vk::Format::X8_D24_UNORM_PACK32,
+        vk::Format::D32_SFLOAT,
+        vk::Format::S8_UINT,
+        vk::Format::D16_UNORM_S8_UINT,
+        vk::Format::D24_UNORM_S8_UINT,
+        vk::Format::D32_SFLOAT_S8_UINT,
+    ]
+    .into_iter()
+    .filter(|format| {
+        let properties = {
+            // SAFETY: `device` belongs to `instance`; format-property queries copy data by value.
+            unsafe {
+                instance
+                    .instance
+                    .get_physical_device_format_properties(device, *format)
+            }
+        };
+        properties
+            .optimal_tiling_features
+            .contains(vk::FormatFeatureFlags::DEPTH_STENCIL_ATTACHMENT)
+    })
+    .map(vk::Format::as_raw)
+    .collect()
+}
diff --git a/adapters/fparkan-render-vulkan/src/ffi/runtime.rs b/adapters/fparkan-render-vulkan/src/ffi/runtime.rs
index 134bf3e..555c08c 100644
--- a/adapters/fparkan-render-vulkan/src/ffi/runtime.rs
+++ b/adapters/fparkan-render-vulkan/src/ffi/runtime.rs
@@ -1,10 +1,11 @@
 #![allow(unsafe_code)]
 
 use ash::vk;
+use fparkan_platform::RenderRequest;
 use std::ffi::CString;
 
 use super::capabilities::{
-    select_live_device_candidate, unique_queue_families, VulkanRuntimeCapabilityError,
+    select_live_device_candidate_for_request, unique_queue_families, VulkanRuntimeCapabilityError,
     VulkanRuntimeCapabilityProbe,
 };
 use super::{VulkanInstanceProbe, VulkanSurfaceProbe};
@@ -125,8 +126,33 @@ pub fn create_vulkan_logical_device_probe(
     surface: &VulkanSurfaceProbe,
     drawable_extent: (u32, u32),
 ) -> Result<VulkanLogicalDeviceProbe, VulkanLogicalDeviceError> {
-    let selected = select_live_device_candidate(instance, surface, drawable_extent)
-        .map_err(VulkanLogicalDeviceError::Runtime)?;
+    create_vulkan_logical_device_probe_for_request(
+        instance,
+        surface,
+        drawable_extent,
+        &RenderRequest::conservative(),
+    )
+}
+
+/// Creates a Vulkan logical device for a specific Stage 0 render request.
+///
+/// # Errors
+///
+/// Returns [`VulkanLogicalDeviceError`] when runtime capability probing fails,
+/// device extension names are invalid, or `vkCreateDevice` fails.
+pub fn create_vulkan_logical_device_probe_for_request(
+    instance: &VulkanInstanceProbe,
+    surface: &VulkanSurfaceProbe,
+    drawable_extent: (u32, u32),
+    render_request: &RenderRequest,
+) -> Result<VulkanLogicalDeviceProbe, VulkanLogicalDeviceError> {
+    let selected = select_live_device_candidate_for_request(
+        instance,
+        surface,
+        drawable_extent,
+        render_request,
+    )
+    .map_err(VulkanLogicalDeviceError::Runtime)?;
     let capability = &selected.runtime.capability;
     let queue_priorities = [1.0_f32];
     let queue_families = unique_queue_families(
diff --git a/adapters/fparkan-render-vulkan/src/ffi/smoke.rs b/adapters/fparkan-render-vulkan/src/ffi/smoke.rs
index 02ea0d6..0274daf 100644
--- a/adapters/fparkan-render-vulkan/src/ffi/smoke.rs
+++ b/adapters/fparkan-render-vulkan/src/ffi/smoke.rs
@@ -5,13 +5,13 @@ use ash::vk;
 use super::{
     create_command_pool, create_frame_sync, create_swapchain_resources,
     create_triangle_index_buffer, create_triangle_vertex_buffer, create_validation_messenger,
-    create_vulkan_instance_probe, create_vulkan_logical_device_probe, create_vulkan_surface_probe,
-    create_vulkan_swapchain_probe_for_extent, destroy_allocated_buffer,
-    destroy_swapchain_resources, plan_vulkan_surface, VulkanAllocatedBuffer, VulkanInstanceConfig,
-    VulkanInstanceProbe, VulkanLogicalDeviceProbe, VulkanSmokeFrameOutcome, VulkanSmokeRenderer,
-    VulkanSmokeRendererCreateInfo, VulkanSmokeRendererError, VulkanSmokeRendererReport,
-    VulkanSurfaceProbe, VulkanSwapchainProbe, VulkanSwapchainResources, VulkanValidationMessenger,
-    VulkanValidationReport,
+    create_vulkan_instance_probe, create_vulkan_logical_device_probe_for_request,
+    create_vulkan_surface_probe, create_vulkan_swapchain_probe_for_extent,
+    destroy_allocated_buffer, destroy_swapchain_resources, plan_vulkan_surface,
+    VulkanAllocatedBuffer, VulkanInstanceConfig, VulkanInstanceProbe, VulkanLogicalDeviceProbe,
+    VulkanSmokeFrameOutcome, VulkanSmokeRenderer, VulkanSmokeRendererCreateInfo,
+    VulkanSmokeRendererError, VulkanSmokeRendererReport, VulkanSurfaceProbe, VulkanSwapchainProbe,
+    VulkanSwapchainResources, VulkanValidationMessenger, VulkanValidationReport,
 };
 use crate::policy::KHR_PORTABILITY_SUBSET_EXTENSION;
 use crate::shader_manifest::{triangle_shader_manifest, validate_shader_manifest};
@@ -106,9 +106,13 @@ impl VulkanSmokeRenderer {
         if let Some(progress) = bootstrap_progress {
             progress.mark_surface_created();
         }
-        let device =
-            create_vulkan_logical_device_probe(&instance, &surface, create_info.drawable_extent)
-                .map_err(VulkanSmokeRendererError::LogicalDevice)?;
+        let device = create_vulkan_logical_device_probe_for_request(
+            &instance,
+            &surface,
+            create_info.drawable_extent,
+            &create_info.render_request,
+        )
+        .map_err(VulkanSmokeRendererError::LogicalDevice)?;
         if let Some(progress) = bootstrap_progress {
             progress.mark_logical_device_created();
         }
diff --git a/adapters/fparkan-render-vulkan/src/ffi/smoke_types.rs b/adapters/fparkan-render-vulkan/src/ffi/smoke_types.rs
index 836f82d..ea4a471 100644
--- a/adapters/fparkan-render-vulkan/src/ffi/smoke_types.rs
+++ b/adapters/fparkan-render-vulkan/src/ffi/smoke_types.rs
@@ -1,5 +1,5 @@
 use ash::vk;
-use fparkan_platform::NativeWindowHandles;
+use fparkan_platform::{NativeWindowHandles, RenderRequest};
 use std::sync::atomic::{AtomicU8, Ordering};
 use std::sync::Arc;
 
@@ -20,6 +20,8 @@ pub struct VulkanSmokeRendererCreateInfo {
     pub native_handles: NativeWindowHandles,
     /// Initial drawable extent.
     pub drawable_extent: (u32, u32),
+    /// Stage 0 render request used for capability gating.
+    pub render_request: RenderRequest,
     /// Whether validation layers must be enabled.
     pub enable_validation: bool,
     /// Optional shared bootstrap progress tracker for failure evidence.
diff --git a/adapters/fparkan-render-vulkan/src/ffi/tests.rs b/adapters/fparkan-render-vulkan/src/ffi/tests.rs
index c242d97..891789d 100644
--- a/adapters/fparkan-render-vulkan/src/ffi/tests.rs
+++ b/adapters/fparkan-render-vulkan/src/ffi/tests.rs
@@ -8,7 +8,7 @@ use crate::shader_manifest::{
     TRIANGLE_VERTEX_SPIRV_PATH, TRIANGLE_VERTEX_VALIDATE_COMMAND,
 };
 use crate::*;
-use fparkan_platform::RenderRequest;
+use fparkan_platform::{DepthStencilSupport, RenderRequest};
 use fparkan_render::{
     DrawCommand, DrawId, GpuMaterialId, GpuMeshId, IndexRange, RenderCommand, RenderPhase,
 };
@@ -288,6 +288,36 @@ fn rejects_missing_graphics_present_swapchain_and_format() {
 }
 
 #[test]
+fn capability_gate_rejects_devices_without_requested_depth_stencil_support() {
+    let mut no_depth = device("No depth", VulkanDeviceType::DiscreteGpu, 0, true, false);
+    no_depth.supported_depth_stencil_formats = vec![vk::Format::D32_SFLOAT.as_raw()];
+
+    assert!(matches!(
+        select_physical_device(&[no_depth]),
+        Err(VulkanCapabilityError::MissingDepthStencilFormat { .. })
+    ));
+}
+
+#[test]
+fn capability_gate_respects_request_specific_depth_profiles() {
+    let mut no_stencil = device("No stencil", VulkanDeviceType::DiscreteGpu, 0, true, false);
+    no_stencil.supported_depth_stencil_formats = vec![vk::Format::D32_SFLOAT.as_raw()];
+    let relaxed_request = RenderRequest {
+        depth: DepthStencilSupport {
+            depth_bits: 32,
+            stencil_bits: 0,
+        },
+        ..RenderRequest::conservative()
+    };
+
+    let report = select_physical_device_for_request(&[no_stencil], &relaxed_request)
+        .expect("selected device for depth-only request");
+
+    assert_eq!(report.device_name, "No stencil");
+    assert!(report.rejected_devices.is_empty());
+}
+
+#[test]
 fn capability_report_json_is_stable() {
     let mut rejected = device("Rejected", VulkanDeviceType::IntegratedGpu, 0, true, false);
     rejected.present_modes.clear();
@@ -660,6 +690,11 @@ fn device(
             vk::PresentModeKHR::MAILBOX.as_raw(),
         ],
         surface_capabilities: default_surface_capabilities(),
+        supported_depth_stencil_formats: vec![
+            vk::Format::D24_UNORM_S8_UINT.as_raw(),
+            vk::Format::D32_SFLOAT_S8_UINT.as_raw(),
+            vk::Format::D32_SFLOAT.as_raw(),
+        ],
     }
 }
 
diff --git a/adapters/fparkan-render-vulkan/src/policy.rs b/adapters/fparkan-render-vulkan/src/policy.rs
index ef9f0c4..040cefb 100644
--- a/adapters/fparkan-render-vulkan/src/policy.rs
+++ b/adapters/fparkan-render-vulkan/src/policy.rs
@@ -1,4 +1,5 @@
 use ash::vk;
+use fparkan_platform::{DepthStencilSupport, RenderRequest};
 use fparkan_render::{validate_command_list, RenderCommand, RenderCommandList, RenderError};
 use serde::Serialize;
 
@@ -182,6 +183,8 @@ pub struct VulkanPhysicalDeviceRecord {
     pub present_modes: Vec<i32>,
     /// Surface capabilities accepted by the target surface.
     pub surface_capabilities: VulkanSwapchainSurfaceCapabilities,
+    /// Depth/stencil attachment formats supported by the device.
+    pub supported_depth_stencil_formats: Vec<i32>,
 }
 
 impl VulkanPhysicalDeviceRecord {
@@ -270,6 +273,13 @@ pub enum VulkanCapabilityError {
         /// Device name that failed validation.
         device: String,
     },
+    /// No compatible depth/stencil attachment format exists for the render request.
+    MissingDepthStencilFormat {
+        /// Device name that failed validation.
+        device: String,
+        /// Requested depth/stencil profile.
+        requested: DepthStencilSupport,
+    },
 }
 
 impl std::fmt::Display for VulkanCapabilityError {
@@ -301,6 +311,12 @@ impl std::fmt::Display for VulkanCapabilityError {
                 f,
                 "Vulkan device {device} surface does not support COLOR_ATTACHMENT usage"
             ),
+            Self::MissingDepthStencilFormat { device, requested } => write!(
+                f,
+                "Vulkan device {device} lacks a depth/stencil attachment format for {}-bit depth and {}-bit stencil",
+                requested.depth_bits,
+                requested.stencil_bits
+            ),
         }
     }
 }
@@ -316,6 +332,20 @@ impl std::error::Error for VulkanCapabilityError {}
 pub fn select_physical_device(
     devices: &[VulkanPhysicalDeviceRecord],
 ) -> Result<VulkanCapabilityReport, VulkanCapabilityError> {
+    select_physical_device_for_request(devices, &RenderRequest::conservative())
+}
+
+/// Selects a Vulkan physical device for a specific Stage 0 render request.
+///
+/// # Errors
+///
+/// Returns [`VulkanCapabilityError`] when no candidate satisfies the minimum
+/// API version, queue, swapchain-extension, surface-format or depth/stencil
+/// requirements for the requested profile.
+pub fn select_physical_device_for_request(
+    devices: &[VulkanPhysicalDeviceRecord],
+    render_request: &RenderRequest,
+) -> Result<VulkanCapabilityReport, VulkanCapabilityError> {
     if devices.is_empty() {
         return Err(VulkanCapabilityError::NoPhysicalDevice);
     }
@@ -324,7 +354,7 @@ pub fn select_physical_device(
     let mut rejected_devices = Vec::new();
     let mut last_error = None;
     for device in devices {
-        let report = match validate_device(device) {
+        let report = match validate_device_for_request(device, render_request) {
             Ok(report) => report,
             Err(err) => {
                 rejected_devices.push(rejected_device_report(device, &err));
@@ -611,8 +641,9 @@ fn select_image_count(capabilities: VulkanSwapchainSurfaceCapabilities) -> u32 {
     }
 }
 
-pub(crate) fn validate_device(
+pub(crate) fn validate_device_for_request(
     device: &VulkanPhysicalDeviceRecord,
+    render_request: &RenderRequest,
 ) -> Result<VulkanCapabilityReport, VulkanCapabilityError> {
     if device.api_version < MIN_VULKAN_API_VERSION {
         return Err(VulkanCapabilityError::ApiVersionTooLow {
@@ -640,6 +671,12 @@ pub(crate) fn validate_device(
             device: device.name.clone(),
         });
     }
+    if !supports_depth_stencil_request(device, render_request.depth) {
+        return Err(VulkanCapabilityError::MissingDepthStencilFormat {
+            device: device.name.clone(),
+            requested: render_request.depth,
+        });
+    }
     let (graphics_queue_family, present_queue_family) = select_queue_families(device)?;
 
     let portability_subset = device.supports_extension(KHR_PORTABILITY_SUBSET_EXTENSION);
@@ -684,6 +721,7 @@ const fn capability_error_code(error: &VulkanCapabilityError) -> &'static str {
         VulkanCapabilityError::MissingColorAttachmentUsage { .. } => {
             "missing_color_attachment_usage"
         }
+        VulkanCapabilityError::MissingDepthStencilFormat { .. } => "missing_depth_stencil_format",
     }
 }
 
@@ -728,6 +766,36 @@ fn supports_color_attachment_usage(capabilities: VulkanSwapchainSurfaceCapabilit
     capabilities.supported_usage_flags & vk::ImageUsageFlags::COLOR_ATTACHMENT.as_raw() != 0
 }
 
+fn supports_depth_stencil_request(
+    device: &VulkanPhysicalDeviceRecord,
+    depth: DepthStencilSupport,
+) -> bool {
+    if depth.depth_bits == 0 && depth.stencil_bits == 0 {
+        return true;
+    }
+    required_depth_stencil_formats(depth).iter().any(|format| {
+        device
+            .supported_depth_stencil_formats
+            .contains(&format.as_raw())
+    })
+}
+
+fn required_depth_stencil_formats(depth: DepthStencilSupport) -> &'static [vk::Format] {
+    match (depth.depth_bits, depth.stencil_bits) {
+        (0, 0) => &[],
+        (16, 0) => &[vk::Format::D16_UNORM, vk::Format::D32_SFLOAT],
+        (24, 0) => &[vk::Format::X8_D24_UNORM_PACK32, vk::Format::D32_SFLOAT],
+        (32, 0) => &[vk::Format::D32_SFLOAT],
+        (16, 8) => &[vk::Format::D16_UNORM_S8_UINT, vk::Format::D24_UNORM_S8_UINT],
+        (24, 8) => &[
+            vk::Format::D24_UNORM_S8_UINT,
+            vk::Format::D32_SFLOAT_S8_UINT,
+        ],
+        (32, 8) => &[vk::Format::D32_SFLOAT_S8_UINT],
+        _ => &[],
+    }
+}
+
 fn score_device(
     device: &VulkanPhysicalDeviceRecord,
     graphics_queue_family: u32,
diff --git a/apps/fparkan-vulkan-smoke/src/main.rs b/apps/fparkan-vulkan-smoke/src/main.rs
index f9c144c..320eb59 100644
--- a/apps/fparkan-vulkan-smoke/src/main.rs
+++ b/apps/fparkan-vulkan-smoke/src/main.rs
@@ -11,6 +11,7 @@
 #![allow(clippy::print_stderr, clippy::print_stdout)]
 //! Native Vulkan smoke runner entrypoint.
 
+use fparkan_platform::RenderRequest;
 use fparkan_platform_winit::{window_native_handles, WinitWindowPlan};
 use fparkan_render_vulkan::{
     VulkanSmokeBootstrapProgress, VulkanSmokeFrameOutcome, VulkanSmokeRenderer,
@@ -524,6 +525,7 @@ impl ApplicationHandler for SmokeApp {
             application_name: "fparkan-vulkan-smoke".to_string(),
             native_handles,
             drawable_extent: (size.width.max(1), size.height.max(1)),
+            render_request: RenderRequest::conservative(),
             enable_validation: true,
             bootstrap_progress: Some(Arc::clone(&self.progress.bootstrap)),
         }) {