feat(stage0): close native smoke acceptance gate

1 files changed, 1895 insertions, 60 deletions

diff --git a/adapters/fparkan-render-vulkan/src/lib.rs b/adapters/fparkan-render-vulkan/src/lib.rs
index 4490d81..e063183 100644
--- a/adapters/fparkan-render-vulkan/src/lib.rs
+++ b/adapters/fparkan-render-vulkan/src/lib.rs
@@ -37,8 +37,11 @@ use fparkan_render::{
     canonical_capture, validate_command_list, FrameOutput, RenderBackend, RenderCommand,
     RenderCommandList, RenderError,
 };
+use std::collections::BTreeSet;
 use std::ffi::{CStr, CString};
 use std::os::raw::c_char;
+use std::sync::atomic::{AtomicU32, Ordering};
+use std::sync::Mutex;
 use std::time::{SystemTime, UNIX_EPOCH};
 
 /// Minimum Vulkan API version accepted by the Stage 0 backend.
@@ -46,35 +49,391 @@ pub const MIN_VULKAN_API_VERSION: u32 = vk::API_VERSION_1_1;
 const KHR_SWAPCHAIN_EXTENSION: &str = "VK_KHR_swapchain";
 const KHR_PORTABILITY_SUBSET_EXTENSION: &str = "VK_KHR_portability_subset";
 const KHR_PORTABILITY_ENUMERATION_EXTENSION: &str = "VK_KHR_portability_enumeration";
+const EXT_DEBUG_UTILS_EXTENSION: &str = "VK_EXT_debug_utils";
+const VALIDATION_LAYER_NAME: &str = "VK_LAYER_KHRONOS_validation";
 const SPIRV_MAGIC: u32 = 0x0723_0203;
 const SPIRV_VERSION_1_0: u32 = 0x0001_0000;
 const TRIANGLE_VERTEX_SHADER_WORDS: &[u32] = &[
     SPIRV_MAGIC,
     SPIRV_VERSION_1_0,
-    0,
-    8,
-    0,
+    0x0008_000b,
+    0x0000_0021,
+    0x0000_0000,
     0x0002_0011,
-    1,
-    0x0006_000F,
-    0,
-    4,
-    0x6E69_616D,
-    0,
+    0x0000_0001,
+    0x0006_000b,
+    0x0000_0001,
+    0x4c53_4c47,
+    0x6474_732e,
+    0x3035_342e,
+    0x0000_0000,
+    0x0003_000e,
+    0x0000_0000,
+    0x0000_0001,
+    0x0009_000f,
+    0x0000_0000,
+    0x0000_0004,
+    0x6e69_616d,
+    0x0000_0000,
+    0x0000_0009,
+    0x0000_000b,
+    0x0000_0013,
+    0x0000_0018,
+    0x0003_0003,
+    0x0000_0002,
+    0x0000_01c2,
+    0x0004_0005,
+    0x0000_0004,
+    0x6e69_616d,
+    0x0000_0000,
+    0x0005_0005,
+    0x0000_0009,
+    0x5f74_756f,
+    0x6f6c_6f63,
+    0x0000_0072,
+    0x0005_0005,
+    0x0000_000b,
+    0x635f_6e69,
+    0x726f_6c6f,
+    0x0000_0000,
+    0x0006_0005,
+    0x0000_0011,
+    0x505f_6c67,
+    0x6556_7265,
+    0x7865_7472,
+    0x0000_0000,
+    0x0006_0006,
+    0x0000_0011,
+    0x0000_0000,
+    0x505f_6c67,
+    0x7469_736f,
+    0x006e_6f69,
+    0x0007_0006,
+    0x0000_0011,
+    0x0000_0001,
+    0x505f_6c67,
+    0x746e_696f,
+    0x657a_6953,
+    0x0000_0000,
+    0x0007_0006,
+    0x0000_0011,
+    0x0000_0002,
+    0x435f_6c67,
+    0x4470_696c,
+    0x6174_7369,
+    0x0065_636e,
+    0x0007_0006,
+    0x0000_0011,
+    0x0000_0003,
+    0x435f_6c67,
+    0x446c_6c75,
+    0x6174_7369,
+    0x0065_636e,
+    0x0003_0005,
+    0x0000_0013,
+    0x0000_0000,
+    0x0005_0005,
+    0x0000_0018,
+    0x705f_6e69,
+    0x7469_736f,
+    0x006e_6f69,
+    0x0004_0047,
+    0x0000_0009,
+    0x0000_001e,
+    0x0000_0000,
+    0x0004_0047,
+    0x0000_000b,
+    0x0000_001e,
+    0x0000_0001,
+    0x0003_0047,
+    0x0000_0011,
+    0x0000_0002,
+    0x0005_0048,
+    0x0000_0011,
+    0x0000_0000,
+    0x0000_000b,
+    0x0000_0000,
+    0x0005_0048,
+    0x0000_0011,
+    0x0000_0001,
+    0x0000_000b,
+    0x0000_0001,
+    0x0005_0048,
+    0x0000_0011,
+    0x0000_0002,
+    0x0000_000b,
+    0x0000_0003,
+    0x0005_0048,
+    0x0000_0011,
+    0x0000_0003,
+    0x0000_000b,
+    0x0000_0004,
+    0x0004_0047,
+    0x0000_0018,
+    0x0000_001e,
+    0x0000_0000,
+    0x0002_0013,
+    0x0000_0002,
+    0x0003_0021,
+    0x0000_0003,
+    0x0000_0002,
+    0x0003_0016,
+    0x0000_0006,
+    0x0000_0020,
+    0x0004_0017,
+    0x0000_0007,
+    0x0000_0006,
+    0x0000_0003,
+    0x0004_0020,
+    0x0000_0008,
+    0x0000_0003,
+    0x0000_0007,
+    0x0004_003b,
+    0x0000_0008,
+    0x0000_0009,
+    0x0000_0003,
+    0x0004_0020,
+    0x0000_000a,
+    0x0000_0001,
+    0x0000_0007,
+    0x0004_003b,
+    0x0000_000a,
+    0x0000_000b,
+    0x0000_0001,
+    0x0004_0017,
+    0x0000_000d,
+    0x0000_0006,
+    0x0000_0004,
+    0x0004_0015,
+    0x0000_000e,
+    0x0000_0020,
+    0x0000_0000,
+    0x0004_002b,
+    0x0000_000e,
+    0x0000_000f,
+    0x0000_0001,
+    0x0004_001c,
+    0x0000_0010,
+    0x0000_0006,
+    0x0000_000f,
+    0x0006_001e,
+    0x0000_0011,
+    0x0000_000d,
+    0x0000_0006,
+    0x0000_0010,
+    0x0000_0010,
+    0x0004_0020,
+    0x0000_0012,
+    0x0000_0003,
+    0x0000_0011,
+    0x0004_003b,
+    0x0000_0012,
+    0x0000_0013,
+    0x0000_0003,
+    0x0004_0015,
+    0x0000_0014,
+    0x0000_0020,
+    0x0000_0001,
+    0x0004_002b,
+    0x0000_0014,
+    0x0000_0015,
+    0x0000_0000,
+    0x0004_0017,
+    0x0000_0016,
+    0x0000_0006,
+    0x0000_0002,
+    0x0004_0020,
+    0x0000_0017,
+    0x0000_0001,
+    0x0000_0016,
+    0x0004_003b,
+    0x0000_0017,
+    0x0000_0018,
+    0x0000_0001,
+    0x0004_002b,
+    0x0000_0006,
+    0x0000_001a,
+    0x0000_0000,
+    0x0004_002b,
+    0x0000_0006,
+    0x0000_001b,
+    0x3f80_0000,
+    0x0004_0020,
+    0x0000_001f,
+    0x0000_0003,
+    0x0000_000d,
+    0x0005_0036,
+    0x0000_0002,
+    0x0000_0004,
+    0x0000_0000,
+    0x0000_0003,
+    0x0002_00f8,
+    0x0000_0005,
+    0x0004_003d,
+    0x0000_0007,
+    0x0000_000c,
+    0x0000_000b,
+    0x0003_003e,
+    0x0000_0009,
+    0x0000_000c,
+    0x0004_003d,
+    0x0000_0016,
+    0x0000_0019,
+    0x0000_0018,
+    0x0005_0051,
+    0x0000_0006,
+    0x0000_001c,
+    0x0000_0019,
+    0x0000_0000,
+    0x0005_0051,
+    0x0000_0006,
+    0x0000_001d,
+    0x0000_0019,
+    0x0000_0001,
+    0x0007_0050,
+    0x0000_000d,
+    0x0000_001e,
+    0x0000_001c,
+    0x0000_001d,
+    0x0000_001a,
+    0x0000_001b,
+    0x0005_0041,
+    0x0000_001f,
+    0x0000_0020,
+    0x0000_0013,
+    0x0000_0015,
+    0x0003_003e,
+    0x0000_0020,
+    0x0000_001e,
+    0x0001_00fd,
+    0x0001_0038,
 ];
 const TRIANGLE_FRAGMENT_SHADER_WORDS: &[u32] = &[
     SPIRV_MAGIC,
     SPIRV_VERSION_1_0,
-    0,
-    8,
-    0,
+    0x0008_000b,
+    0x0000_0013,
+    0x0000_0000,
     0x0002_0011,
-    1,
-    0x0006_000F,
-    4,
-    4,
-    0x6E69_616D,
-    0,
+    0x0000_0001,
+    0x0006_000b,
+    0x0000_0001,
+    0x4c53_4c47,
+    0x6474_732e,
+    0x3035_342e,
+    0x0000_0000,
+    0x0003_000e,
+    0x0000_0000,
+    0x0000_0001,
+    0x0007_000f,
+    0x0000_0004,
+    0x0000_0004,
+    0x6e69_616d,
+    0x0000_0000,
+    0x0000_0009,
+    0x0000_000c,
+    0x0003_0010,
+    0x0000_0004,
+    0x0000_0007,
+    0x0003_0003,
+    0x0000_0002,
+    0x0000_01c2,
+    0x0004_0005,
+    0x0000_0004,
+    0x6e69_616d,
+    0x0000_0000,
+    0x0005_0005,
+    0x0000_0009,
+    0x5f74_756f,
+    0x6f6c_6f63,
+    0x0000_0072,
+    0x0005_0005,
+    0x0000_000c,
+    0x635f_6e69,
+    0x726f_6c6f,
+    0x0000_0000,
+    0x0004_0047,
+    0x0000_0009,
+    0x0000_001e,
+    0x0000_0000,
+    0x0004_0047,
+    0x0000_000c,
+    0x0000_001e,
+    0x0000_0000,
+    0x0002_0013,
+    0x0000_0002,
+    0x0003_0021,
+    0x0000_0003,
+    0x0000_0002,
+    0x0003_0016,
+    0x0000_0006,
+    0x0000_0020,
+    0x0004_0017,
+    0x0000_0007,
+    0x0000_0006,
+    0x0000_0004,
+    0x0004_0020,
+    0x0000_0008,
+    0x0000_0003,
+    0x0000_0007,
+    0x0004_003b,
+    0x0000_0008,
+    0x0000_0009,
+    0x0000_0003,
+    0x0004_0017,
+    0x0000_000a,
+    0x0000_0006,
+    0x0000_0003,
+    0x0004_0020,
+    0x0000_000b,
+    0x0000_0001,
+    0x0000_000a,
+    0x0004_003b,
+    0x0000_000b,
+    0x0000_000c,
+    0x0000_0001,
+    0x0004_002b,
+    0x0000_0006,
+    0x0000_000e,
+    0x3f80_0000,
+    0x0005_0036,
+    0x0000_0002,
+    0x0000_0004,
+    0x0000_0000,
+    0x0000_0003,
+    0x0002_00f8,
+    0x0000_0005,
+    0x0004_003d,
+    0x0000_000a,
+    0x0000_000d,
+    0x0000_000c,
+    0x0005_0051,
+    0x0000_0006,
+    0x0000_000f,
+    0x0000_000d,
+    0x0000_0000,
+    0x0005_0051,
+    0x0000_0006,
+    0x0000_0010,
+    0x0000_000d,
+    0x0000_0001,
+    0x0005_0051,
+    0x0000_0006,
+    0x0000_0011,
+    0x0000_000d,
+    0x0000_0002,
+    0x0007_0050,
+    0x0000_0007,
+    0x0000_0012,
+    0x0000_000f,
+    0x0000_0010,
+    0x0000_0011,
+    0x0000_000e,
+    0x0003_003e,
+    0x0000_0009,
+    0x0000_0012,
+    0x0001_00fd,
+    0x0001_0038,
 ];
 
 /// Shader compiler/toolchain identifiers pinned in the Stage 0 manifest.
@@ -462,6 +821,10 @@ impl std::fmt::Display for VulkanSmokeRunError {
 impl std::error::Error for VulkanSmokeRunError {}
 
 /// Runs a minimal native smoke loop: acquire/present without recording commands.
+///
+/// # Errors
+///
+/// Returns [`VulkanSmokeRunError`] when swapchain acquisition, recreation, or presentation fails.
 pub fn run_vulkan_smoke_pass(
     instance: &VulkanInstanceProbe,
     surface: &VulkanSurfaceProbe,
@@ -475,6 +838,7 @@ pub fn run_vulkan_smoke_pass(
 
     let image_available = vk::SemaphoreCreateInfo::default();
     let image_ready =
+        // SAFETY: The semaphore is created on this live logical device and destroyed before return.
         unsafe { device.device().create_semaphore(&image_available, None) }.map_err(|error| {
             VulkanSmokeRunError::RecreateSwapchain {
                 result: format!("{error:?}"),
@@ -505,6 +869,7 @@ pub fn run_vulkan_smoke_pass(
             created = created.saturating_add(1);
         }
 
+        // SAFETY: The swapchain and synchronization primitives are live for the duration of the acquire call.
         let image_index = unsafe {
             swapchain.loader().acquire_next_image(
                 swapchain.swapchain(),
@@ -525,6 +890,7 @@ pub fn run_vulkan_smoke_pass(
             .wait_semaphores(&present_wait_semaphores)
             .swapchains(&swapchains)
             .image_indices(&image_indices);
+        // SAFETY: Presentation uses the acquired image index and waits on the semaphore signaled by acquire.
         unsafe {
             swapchain
                 .loader()
@@ -534,6 +900,7 @@ pub fn run_vulkan_smoke_pass(
             result: format!("{error:?}"),
         })?;
 
+        // SAFETY: The queue belongs to this live logical device and is idle-waited at the end of the smoke iteration.
         unsafe { device.device().queue_wait_idle(render_queue) }.map_err(|error| {
             VulkanSmokeRunError::PresentImage {
                 result: format!("{error:?}"),
@@ -543,6 +910,7 @@ pub fn run_vulkan_smoke_pass(
         swaps = swaps.saturating_add(1);
     }
 
+    // SAFETY: The semaphore was created above on this logical device and is destroyed exactly once.
     unsafe { device.device().destroy_semaphore(image_ready, None) }
 
     Ok(VulkanSmokeRunReport {
@@ -552,6 +920,1344 @@ pub fn run_vulkan_smoke_pass(
     })
 }
 
+/// Creates a live native Vulkan renderer for the Stage 0 smoke loop.
+#[derive(Clone, Debug)]
+pub struct VulkanSmokeRendererCreateInfo {
+    /// Application name reported to the Vulkan loader.
+    pub application_name: String,
+    /// Native window/display handles borrowed from a live window.
+    pub native_handles: NativeWindowHandles,
+    /// Initial drawable extent.
+    pub drawable_extent: (u32, u32),
+    /// Whether validation layers must be enabled.
+    pub enable_validation: bool,
+}
+
+/// Stable smoke renderer bootstrap report.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct VulkanSmokeRendererReport {
+    /// Whether portability enumeration was enabled at instance creation.
+    pub portability_enumeration: bool,
+    /// Selected device name.
+    pub device_name: String,
+    /// Graphics queue-family index.
+    pub graphics_queue_family: u32,
+    /// Present queue-family index.
+    pub present_queue_family: u32,
+    /// Enabled logical-device extension count.
+    pub enabled_extension_count: u32,
+    /// Current swapchain extent.
+    pub swapchain_extent: (u32, u32),
+    /// Current swapchain image count.
+    pub swapchain_image_count: u32,
+}
+
+/// Measured validation counters from the live smoke loop.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct VulkanValidationReport {
+    /// Validation warnings observed by the debug messenger.
+    pub warning_count: u32,
+    /// Validation errors observed by the debug messenger.
+    pub error_count: u32,
+    /// Stable sorted VUID list.
+    pub vuids: Vec<String>,
+}
+
+/// Result of one rendered smoke frame.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum VulkanSmokeFrameOutcome {
+    /// A frame was submitted and presented.
+    Presented,
+    /// Rendering was skipped because the swapchain had to be recreated.
+    Recreated,
+    /// Rendering was skipped because the drawable extent is zero.
+    ZeroExtent,
+}
+
+/// Live smoke renderer error.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum VulkanSmokeRendererError {
+    /// Instance bootstrap failed.
+    Instance(VulkanInstanceError),
+    /// Surface bootstrap failed.
+    Surface(VulkanSurfaceError),
+    /// Logical-device bootstrap failed.
+    LogicalDevice(VulkanLogicalDeviceError),
+    /// Swapchain bootstrap failed.
+    Swapchain(VulkanSwapchainProbeError),
+    /// Shader manifest validation failed.
+    ShaderManifest(VulkanShaderManifestError),
+    /// Vulkan operation failed.
+    VulkanOperation {
+        /// Operation context.
+        context: &'static str,
+        /// Raw Vulkan result text.
+        result: String,
+    },
+    /// No suitable memory type exists for the required properties.
+    MissingMemoryType {
+        /// Operation context.
+        context: &'static str,
+    },
+    /// Internal smoke renderer state was unexpectedly absent.
+    InvariantViolation {
+        /// Missing state context.
+        context: &'static str,
+    },
+}
+
+impl std::fmt::Display for VulkanSmokeRendererError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Instance(error) => write!(f, "{error}"),
+            Self::Surface(error) => write!(f, "{error}"),
+            Self::LogicalDevice(error) => write!(f, "{error}"),
+            Self::Swapchain(error) => write!(f, "{error}"),
+            Self::ShaderManifest(error) => write!(f, "{error}"),
+            Self::VulkanOperation { context, result } => {
+                write!(f, "{context}: {result}")
+            }
+            Self::MissingMemoryType { context } => {
+                write!(f, "{context}: no compatible Vulkan memory type")
+            }
+            Self::InvariantViolation { context } => {
+                write!(f, "renderer invariant violated: {context}")
+            }
+        }
+    }
+}
+
+impl std::error::Error for VulkanSmokeRendererError {}
+
+struct VulkanValidationShared {
+    warning_count: AtomicU32,
+    error_count: AtomicU32,
+    vuids: Mutex<BTreeSet<String>>,
+}
+
+impl Default for VulkanValidationShared {
+    fn default() -> Self {
+        Self {
+            warning_count: AtomicU32::new(0),
+            error_count: AtomicU32::new(0),
+            vuids: Mutex::new(BTreeSet::new()),
+        }
+    }
+}
+
+struct VulkanValidationMessenger {
+    loader: ash::ext::debug_utils::Instance,
+    messenger: vk::DebugUtilsMessengerEXT,
+    shared: Box<VulkanValidationShared>,
+}
+
+impl VulkanValidationMessenger {
+    fn report(&self) -> VulkanValidationReport {
+        let vuids = self
+            .shared
+            .vuids
+            .lock()
+            .map(|values| values.iter().cloned().collect::<Vec<_>>())
+            .unwrap_or_default();
+        VulkanValidationReport {
+            warning_count: self.shared.warning_count.load(Ordering::Relaxed),
+            error_count: self.shared.error_count.load(Ordering::Relaxed),
+            vuids,
+        }
+    }
+}
+
+impl Drop for VulkanValidationMessenger {
+    fn drop(&mut self) {
+        // SAFETY: The messenger belongs to this instance-level loader and is destroyed once.
+        unsafe {
+            self.loader
+                .destroy_debug_utils_messenger(self.messenger, None);
+        };
+    }
+}
+
+unsafe extern "system" fn vulkan_validation_callback(
+    message_severity: vk::DebugUtilsMessageSeverityFlagsEXT,
+    _message_types: vk::DebugUtilsMessageTypeFlagsEXT,
+    callback_data: *const vk::DebugUtilsMessengerCallbackDataEXT<'_>,
+    user_data: *mut std::ffi::c_void,
+) -> vk::Bool32 {
+    // SAFETY: The debug messenger stores a stable pointer to `VulkanValidationShared` for the messenger lifetime.
+    let Some(shared) = (unsafe { (user_data as *const VulkanValidationShared).as_ref() }) else {
+        return vk::FALSE;
+    };
+    if message_severity.contains(vk::DebugUtilsMessageSeverityFlagsEXT::ERROR) {
+        shared.error_count.fetch_add(1, Ordering::Relaxed);
+    } else if message_severity.contains(vk::DebugUtilsMessageSeverityFlagsEXT::WARNING) {
+        shared.warning_count.fetch_add(1, Ordering::Relaxed);
+    }
+    // SAFETY: Vulkan invokes the callback with either a null pointer or a valid callback-data payload.
+    let Some(callback_data) = (unsafe { callback_data.as_ref() }) else {
+        return vk::FALSE;
+    };
+    if let Some(vuid) = (!callback_data.p_message_id_name.is_null()).then(|| {
+        // SAFETY: `p_message_id_name` is a Vulkan-owned NUL-terminated string for the callback duration.
+        unsafe { CStr::from_ptr(callback_data.p_message_id_name) }
+            .to_string_lossy()
+            .into_owned()
+    }) {
+        if vuid.starts_with("VUID-") {
+            if let Ok(mut vuids) = shared.vuids.lock() {
+                vuids.insert(vuid);
+            }
+        }
+    }
+    vk::FALSE
+}
+
+struct VulkanAllocatedBuffer {
+    buffer: vk::Buffer,
+    memory: vk::DeviceMemory,
+}
+
+struct VulkanSwapchainResources {
+    image_views: Vec<vk::ImageView>,
+    render_pass: vk::RenderPass,
+    pipeline_layout: vk::PipelineLayout,
+    pipeline: vk::Pipeline,
+    framebuffers: Vec<vk::Framebuffer>,
+    command_buffers: Vec<vk::CommandBuffer>,
+}
+
+struct VulkanFrameSync {
+    image_available: vk::Semaphore,
+    render_finished: vk::Semaphore,
+    fence: vk::Fence,
+}
+
+/// Live Stage 0 Vulkan triangle renderer used by the smoke app.
+pub struct VulkanSmokeRenderer {
+    instance: Option<VulkanInstanceProbe>,
+    validation: Option<VulkanValidationMessenger>,
+    surface: Option<VulkanSurfaceProbe>,
+    device: Option<VulkanLogicalDeviceProbe>,
+    swapchain: Option<VulkanSwapchainProbe>,
+    command_pool: vk::CommandPool,
+    swapchain_resources: Option<VulkanSwapchainResources>,
+    vertex_buffer: Option<VulkanAllocatedBuffer>,
+    index_buffer: Option<VulkanAllocatedBuffer>,
+    frame_sync: Vec<VulkanFrameSync>,
+    images_in_flight: Vec<vk::Fence>,
+    current_frame: usize,
+    pending_extent: Option<(u32, u32)>,
+    swapchain_recreate_count: u32,
+    report: VulkanSmokeRendererReport,
+}
+
+impl VulkanSmokeRenderer {
+    /// Creates a live Vulkan smoke renderer bound to a live native window.
+    ///
+    /// # Errors
+    ///
+    /// Returns [`VulkanSmokeRendererError`] when Vulkan bootstrap, pipeline creation,
+    /// memory allocation, or synchronization resource creation fails.
+    pub fn new(
+        create_info: &VulkanSmokeRendererCreateInfo,
+    ) -> Result<Self, VulkanSmokeRendererError> {
+        validate_shader_manifest(&triangle_shader_manifest())
+            .map_err(VulkanSmokeRendererError::ShaderManifest)?;
+        let surface_plan = plan_vulkan_surface(Some(create_info.native_handles))
+            .map_err(VulkanSmokeRendererError::Surface)?;
+        let mut instance_config = VulkanInstanceConfig::smoke(&create_info.application_name);
+        instance_config
+            .required_extensions
+            .clone_from(&surface_plan.required_instance_extensions);
+        instance_config.enable_validation = create_info.enable_validation;
+        let instance = create_vulkan_instance_probe(&instance_config)
+            .map_err(VulkanSmokeRendererError::Instance)?;
+        let validation = if create_info.enable_validation {
+            Some(create_validation_messenger(&instance)?)
+        } else {
+            None
+        };
+        let surface = create_vulkan_surface_probe(&instance, Some(create_info.native_handles))
+            .map_err(VulkanSmokeRendererError::Surface)?;
+        let device =
+            create_vulkan_logical_device_probe(&instance, &surface, create_info.drawable_extent)
+                .map_err(VulkanSmokeRendererError::LogicalDevice)?;
+        let swapchain = create_vulkan_swapchain_probe_for_extent(
+            &instance,
+            &surface,
+            &device,
+            create_info.drawable_extent,
+            vk::SwapchainKHR::null(),
+        )
+        .map_err(VulkanSmokeRendererError::Swapchain)?;
+        let command_pool = create_command_pool(&device)?;
+        let vertex_buffer = Some(create_triangle_vertex_buffer(&instance, &device)?);
+        let index_buffer = Some(create_triangle_index_buffer(&instance, &device)?);
+        let mut renderer = Self {
+            instance: Some(instance),
+            validation,
+            surface: Some(surface),
+            device: Some(device),
+            swapchain: Some(swapchain),
+            command_pool,
+            swapchain_resources: None,
+            vertex_buffer,
+            index_buffer,
+            frame_sync: Vec::new(),
+            images_in_flight: Vec::new(),
+            current_frame: 0,
+            pending_extent: None,
+            swapchain_recreate_count: 0,
+            report: VulkanSmokeRendererReport {
+                portability_enumeration: instance_config.enable_portability_enumeration,
+                device_name: String::new(),
+                graphics_queue_family: 0,
+                present_queue_family: 0,
+                enabled_extension_count: 0,
+                swapchain_extent: (0, 0),
+                swapchain_image_count: 0,
+            },
+        };
+        renderer.rebuild_swapchain_resources(false)?;
+        let device_ref = renderer.device_ref()?;
+        let swapchain_ref = renderer.swapchain_ref()?;
+        renderer.report = VulkanSmokeRendererReport {
+            portability_enumeration: renderer
+                .instance
+                .as_ref()
+                .is_some_and(|instance| instance.report.create_flags != 0),
+            device_name: device_ref.report.device_name.clone(),
+            graphics_queue_family: device_ref.report.graphics_queue_family,
+            present_queue_family: device_ref.report.present_queue_family,
+            enabled_extension_count: device_ref
+                .report
+                .enabled_extensions
+                .len()
+                .try_into()
+                .unwrap_or(u32::MAX),
+            swapchain_extent: swapchain_ref.report.plan.extent,
+            swapchain_image_count: swapchain_ref.report.image_count,
+        };
+        Ok(renderer)
+    }
+
+    /// Returns the current bootstrap report.
+    #[must_use]
+    pub const fn report(&self) -> &VulkanSmokeRendererReport {
+        &self.report
+    }
+
+    /// Returns measured validation counters and VUIDs.
+    #[must_use]
+    pub fn validation_report(&self) -> VulkanValidationReport {
+        self.validation.as_ref().map_or(
+            VulkanValidationReport {
+                warning_count: 0,
+                error_count: 0,
+                vuids: Vec::new(),
+            },
+            VulkanValidationMessenger::report,
+        )
+    }
+
+    /// Returns the measured swapchain recreation count.
+    #[must_use]
+    pub const fn swapchain_recreate_count(&self) -> u32 {
+        self.swapchain_recreate_count
+    }
+
+    /// Requests swapchain recreation for a new drawable extent.
+    pub fn request_resize(&mut self, extent: (u32, u32)) {
+        self.pending_extent = Some(extent);
+    }
+
+    fn device_ref(&self) -> Result<&VulkanLogicalDeviceProbe, VulkanSmokeRendererError> {
+        self.device
+            .as_ref()
+            .ok_or(VulkanSmokeRendererError::InvariantViolation {
+                context: "logical device",
+            })
+    }
+
+    fn swapchain_ref(&self) -> Result<&VulkanSwapchainProbe, VulkanSmokeRendererError> {
+        self.swapchain
+            .as_ref()
+            .ok_or(VulkanSmokeRendererError::InvariantViolation {
+                context: "swapchain",
+            })
+    }
+
+    fn instance_ref(&self) -> Result<&VulkanInstanceProbe, VulkanSmokeRendererError> {
+        self.instance
+            .as_ref()
+            .ok_or(VulkanSmokeRendererError::InvariantViolation {
+                context: "instance",
+            })
+    }
+
+    fn surface_ref(&self) -> Result<&VulkanSurfaceProbe, VulkanSmokeRendererError> {
+        self.surface
+            .as_ref()
+            .ok_or(VulkanSmokeRendererError::InvariantViolation { context: "surface" })
+    }
+
+    fn resources_ref(&self) -> Result<&VulkanSwapchainResources, VulkanSmokeRendererError> {
+        self.swapchain_resources
+            .as_ref()
+            .ok_or(VulkanSmokeRendererError::InvariantViolation {
+                context: "swapchain resources",
+            })
+    }
+
+    fn vertex_buffer_ref(&self) -> Result<&VulkanAllocatedBuffer, VulkanSmokeRendererError> {
+        self.vertex_buffer
+            .as_ref()
+            .ok_or(VulkanSmokeRendererError::InvariantViolation {
+                context: "vertex buffer",
+            })
+    }
+
+    fn index_buffer_ref(&self) -> Result<&VulkanAllocatedBuffer, VulkanSmokeRendererError> {
+        self.index_buffer
+            .as_ref()
+            .ok_or(VulkanSmokeRendererError::InvariantViolation {
+                context: "index buffer",
+            })
+    }
+
+    /// Draws and presents one indexed-triangle frame.
+    ///
+    /// # Errors
+    ///
+    /// Returns [`VulkanSmokeRendererError`] when synchronization, command recording,
+    /// submission, or presentation fails.
+    #[allow(clippy::too_many_lines)]
+    pub fn draw_frame(&mut self) -> Result<VulkanSmokeFrameOutcome, VulkanSmokeRendererError> {
+        if let Some(extent) = self.pending_extent.take() {
+            if extent.0 == 0 || extent.1 == 0 {
+                self.pending_extent = Some(extent);
+                return Ok(VulkanSmokeFrameOutcome::ZeroExtent);
+            }
+            self.recreate_swapchain(extent)?;
+            return Ok(VulkanSmokeFrameOutcome::Recreated);
+        }
+
+        let sync = &self.frame_sync[self.current_frame];
+        let image_available = sync.image_available;
+        let render_finished = sync.render_finished;
+        let in_flight_fence = sync.fence;
+        // SAFETY: The fence belongs to this live logical device and is waited from one thread.
+        unsafe {
+            self.device_ref()?
+                .device()
+                .wait_for_fences(&[in_flight_fence], true, 1_000_000_000)
+        }
+        .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+            context: "vkWaitForFences",
+            result: format!("{error:?}"),
+        })?;
+        // SAFETY: The swapchain, semaphore and fence inputs are live for the duration of the acquire call.
+        let acquire = unsafe {
+            self.swapchain_ref()?.loader().acquire_next_image(
+                self.swapchain_ref()?.swapchain(),
+                1_000_000_000,
+                image_available,
+                vk::Fence::null(),
+            )
+        };
+        let (image_index, acquire_suboptimal) = match acquire {
+            Ok(result) => result,
+            Err(vk::Result::ERROR_OUT_OF_DATE_KHR) => {
+                self.recreate_swapchain(self.report.swapchain_extent)?;
+                return Ok(VulkanSmokeFrameOutcome::Recreated);
+            }
+            Err(error) => {
+                return Err(VulkanSmokeRendererError::VulkanOperation {
+                    context: "vkAcquireNextImageKHR",
+                    result: format!("{error:?}"),
+                });
+            }
+        };
+        let image_index_usize = usize::try_from(image_index).unwrap_or(0);
+        let image_fence = self.images_in_flight[image_index_usize];
+        if image_fence != vk::Fence::null() {
+            // SAFETY: The fence belongs to this renderer and can be waited independently.
+            unsafe {
+                self.device_ref()?
+                    .device()
+                    .wait_for_fences(&[image_fence], true, 1_000_000_000)
+            }
+            .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+                context: "vkWaitForFences(image)",
+                result: format!("{error:?}"),
+            })?;
+        }
+        self.images_in_flight[image_index_usize] = in_flight_fence;
+        // SAFETY: The fence belongs to this frame context and is not in use after the wait above.
+        unsafe { self.device_ref()?.device().reset_fences(&[in_flight_fence]) }.map_err(
+            |error| VulkanSmokeRendererError::VulkanOperation {
+                context: "vkResetFences",
+                result: format!("{error:?}"),
+            },
+        )?;
+
+        self.record_command_buffer(image_index_usize)?;
+        let wait_semaphores = [image_available];
+        let wait_stages = [vk::PipelineStageFlags::COLOR_ATTACHMENT_OUTPUT];
+        let command_buffers = [self.resources_ref()?.command_buffers[image_index_usize]];
+        let signal_semaphores = [render_finished];
+        let submit_info = [vk::SubmitInfo::default()
+            .wait_semaphores(&wait_semaphores)
+            .wait_dst_stage_mask(&wait_stages)
+            .command_buffers(&command_buffers)
+            .signal_semaphores(&signal_semaphores)];
+        // SAFETY: Submission references live queue, sync objects and recorded command buffer.
+        unsafe {
+            self.device_ref()?.device().queue_submit(
+                self.device_ref()?.graphics_queue(),
+                &submit_info,
+                in_flight_fence,
+            )
+        }
+        .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+            context: "vkQueueSubmit",
+            result: format!("{error:?}"),
+        })?;
+
+        let present_wait = [render_finished];
+        let swapchains = [self.swapchain_ref()?.swapchain()];
+        let image_indices = [image_index];
+        let present_info = vk::PresentInfoKHR::default()
+            .wait_semaphores(&present_wait)
+            .swapchains(&swapchains)
+            .image_indices(&image_indices);
+        // SAFETY: Presentation uses the rendered image index and a semaphore signaled by queue submission.
+        let present_suboptimal = match unsafe {
+            self.swapchain_ref()?
+                .loader()
+                .queue_present(self.device_ref()?.present_queue(), &present_info)
+        } {
+            Ok(suboptimal) => suboptimal,
+            Err(vk::Result::ERROR_OUT_OF_DATE_KHR) => {
+                self.recreate_swapchain(self.report.swapchain_extent)?;
+                return Ok(VulkanSmokeFrameOutcome::Recreated);
+            }
+            Err(error) => {
+                return Err(VulkanSmokeRendererError::VulkanOperation {
+                    context: "vkQueuePresentKHR",
+                    result: format!("{error:?}"),
+                });
+            }
+        };
+
+        self.current_frame = (self.current_frame + 1) % self.frame_sync.len().max(1);
+        if acquire_suboptimal || present_suboptimal {
+            self.recreate_swapchain(self.report.swapchain_extent)?;
+            Ok(VulkanSmokeFrameOutcome::Recreated)
+        } else {
+            Ok(VulkanSmokeFrameOutcome::Presented)
+        }
+    }
+
+    fn recreate_swapchain(&mut self, extent: (u32, u32)) -> Result<(), VulkanSmokeRendererError> {
+        let device = self.device_ref()?;
+        // SAFETY: The logical device remains live and idling at swapchain recreation boundaries.
+        unsafe { device.device().device_wait_idle() }.map_err(|error| {
+            VulkanSmokeRendererError::VulkanOperation {
+                context: "vkDeviceWaitIdle",
+                result: format!("{error:?}"),
+            }
+        })?;
+        self.pending_extent = None;
+        self.rebuild_swapchain(extent)?;
+        self.swapchain_recreate_count = self.swapchain_recreate_count.saturating_add(1);
+        Ok(())
+    }
+
+    fn rebuild_swapchain(&mut self, extent: (u32, u32)) -> Result<(), VulkanSmokeRendererError> {
+        self.destroy_swapchain_resources();
+        let instance = self.instance_ref()?;
+        let surface = self.surface_ref()?;
+        let device = self.device_ref()?;
+        let old_swapchain = self
+            .swapchain
+            .as_ref()
+            .map_or(vk::SwapchainKHR::null(), VulkanSwapchainProbe::swapchain);
+        let new_swapchain = create_vulkan_swapchain_probe_for_extent(
+            instance,
+            surface,
+            device,
+            extent,
+            old_swapchain,
+        )
+        .map_err(VulkanSmokeRendererError::Swapchain)?;
+        self.swapchain = Some(new_swapchain);
+        self.rebuild_swapchain_resources(true)?;
+        Ok(())
+    }
+
+    fn rebuild_swapchain_resources(
+        &mut self,
+        reuse_command_pool: bool,
+    ) -> Result<(), VulkanSmokeRendererError> {
+        let resources = {
+            let device = self.device_ref()?;
+            let swapchain = self.swapchain_ref()?;
+            create_swapchain_resources(
+                device,
+                swapchain,
+                self.command_pool,
+                self.vertex_buffer_ref()?,
+                self.index_buffer_ref()?,
+                reuse_command_pool,
+            )?
+        };
+        let frame_sync = {
+            let device = self.device_ref()?;
+            create_frame_sync(device)?
+        };
+        let swapchain_extent = self.swapchain_ref()?.report.plan.extent;
+        let swapchain_image_count = self.swapchain_ref()?.report.image_count;
+        self.images_in_flight = vec![vk::Fence::null(); resources.image_views.len()];
+        self.frame_sync = frame_sync;
+        self.report.swapchain_extent = swapchain_extent;
+        self.report.swapchain_image_count = swapchain_image_count;
+        self.swapchain_resources = Some(resources);
+        Ok(())
+    }
+
+    #[allow(clippy::too_many_lines)]
+    fn record_command_buffer(
+        &mut self,
+        image_index: usize,
+    ) -> Result<(), VulkanSmokeRendererError> {
+        let device = self.device_ref()?;
+        let swapchain = self.swapchain_ref()?;
+        let resources = self.resources_ref()?;
+        let command_buffer = resources.command_buffers[image_index];
+        // SAFETY: The command buffer belongs to the resettable pool owned by this renderer.
+        unsafe {
+            device
+                .device()
+                .reset_command_buffer(command_buffer, vk::CommandBufferResetFlags::empty())
+        }
+        .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+            context: "vkResetCommandBuffer",
+            result: format!("{error:?}"),
+        })?;
+        let begin_info = vk::CommandBufferBeginInfo::default();
+        // SAFETY: The command buffer is in the initial state after reset and recorded on one thread.
+        unsafe {
+            device
+                .device()
+                .begin_command_buffer(command_buffer, &begin_info)
+        }
+        .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+            context: "vkBeginCommandBuffer",
+            result: format!("{error:?}"),
+        })?;
+
+        let pre_barrier = vk::ImageMemoryBarrier::default()
+            .old_layout(vk::ImageLayout::PRESENT_SRC_KHR)
+            .new_layout(vk::ImageLayout::COLOR_ATTACHMENT_OPTIMAL)
+            .src_queue_family_index(vk::QUEUE_FAMILY_IGNORED)
+            .dst_queue_family_index(vk::QUEUE_FAMILY_IGNORED)
+            .subresource_range(color_subresource_range())
+            .src_access_mask(vk::AccessFlags::empty())
+            .dst_access_mask(vk::AccessFlags::COLOR_ATTACHMENT_WRITE);
+        // SAFETY: The swapchain is live and queried only to resolve the current image handles.
+        let swapchain_images = unsafe {
+            swapchain
+                .loader()
+                .get_swapchain_images(swapchain.swapchain())
+        }
+        .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+            context: "vkGetSwapchainImagesKHR",
+            result: format!("{error:?}"),
+        })?;
+        let pre_barrier = pre_barrier.image(swapchain_images[image_index]);
+        // SAFETY: The barriers operate on the acquired swapchain image owned by this command buffer submission.
+        unsafe {
+            device.device().cmd_pipeline_barrier(
+                command_buffer,
+                vk::PipelineStageFlags::COLOR_ATTACHMENT_OUTPUT,
+                vk::PipelineStageFlags::COLOR_ATTACHMENT_OUTPUT,
+                vk::DependencyFlags::empty(),
+                &[],
+                &[],
+                &[pre_barrier],
+            );
+        }
+
+        let clear_values = [vk::ClearValue {
+            color: vk::ClearColorValue {
+                float32: [0.05, 0.08, 0.11, 1.0],
+            },
+        }];
+        let render_area = vk::Rect2D {
+            offset: vk::Offset2D { x: 0, y: 0 },
+            extent: vk::Extent2D {
+                width: swapchain.report.plan.extent.0,
+                height: swapchain.report.plan.extent.1,
+            },
+        };
+        let render_pass_info = vk::RenderPassBeginInfo::default()
+            .render_pass(resources.render_pass)
+            .framebuffer(resources.framebuffers[image_index])
+            .render_area(render_area)
+            .clear_values(&clear_values);
+        // SAFETY: All commands target live frame resources owned by this renderer.
+        unsafe {
+            device.device().cmd_begin_render_pass(
+                command_buffer,
+                &render_pass_info,
+                vk::SubpassContents::INLINE,
+            );
+            device.device().cmd_bind_pipeline(
+                command_buffer,
+                vk::PipelineBindPoint::GRAPHICS,
+                resources.pipeline,
+            );
+            let vertex_buffers = [self.vertex_buffer_ref()?.buffer];
+            let offsets = [0_u64];
+            device
+                .device()
+                .cmd_bind_vertex_buffers(command_buffer, 0, &vertex_buffers, &offsets);
+            device.device().cmd_bind_index_buffer(
+                command_buffer,
+                self.index_buffer_ref()?.buffer,
+                0,
+                vk::IndexType::UINT16,
+            );
+            device
+                .device()
+                .cmd_draw_indexed(command_buffer, 3, 1, 0, 0, 0);
+            device.device().cmd_end_render_pass(command_buffer);
+        }
+
+        let post_barrier = vk::ImageMemoryBarrier::default()
+            .old_layout(vk::ImageLayout::COLOR_ATTACHMENT_OPTIMAL)
+            .new_layout(vk::ImageLayout::PRESENT_SRC_KHR)
+            .src_queue_family_index(vk::QUEUE_FAMILY_IGNORED)
+            .dst_queue_family_index(vk::QUEUE_FAMILY_IGNORED)
+            .image(swapchain_images[image_index])
+            .subresource_range(color_subresource_range())
+            .src_access_mask(vk::AccessFlags::COLOR_ATTACHMENT_WRITE)
+            .dst_access_mask(vk::AccessFlags::empty());
+        // SAFETY: The post-render barrier transitions the same live swapchain image into present layout.
+        unsafe {
+            device.device().cmd_pipeline_barrier(
+                command_buffer,
+                vk::PipelineStageFlags::COLOR_ATTACHMENT_OUTPUT,
+                vk::PipelineStageFlags::BOTTOM_OF_PIPE,
+                vk::DependencyFlags::empty(),
+                &[],
+                &[],
+                &[post_barrier],
+            );
+            device.device().end_command_buffer(command_buffer)
+        }
+        .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+            context: "vkEndCommandBuffer",
+            result: format!("{error:?}"),
+        })?;
+        Ok(())
+    }
+
+    fn destroy_swapchain_resources(&mut self) {
+        let Some(device) = self.device.as_ref() else {
+            return;
+        };
+        for sync in self.frame_sync.drain(..) {
+            // SAFETY: These sync objects belong to this device and are destroyed once.
+            unsafe {
+                device
+                    .device()
+                    .destroy_semaphore(sync.image_available, None);
+                device
+                    .device()
+                    .destroy_semaphore(sync.render_finished, None);
+                device.device().destroy_fence(sync.fence, None);
+            }
+        }
+        if let Some(resources) = self.swapchain_resources.take() {
+            destroy_swapchain_resources(device, self.command_pool, resources);
+        }
+    }
+}
+
+impl Drop for VulkanSmokeRenderer {
+    fn drop(&mut self) {
+        self.destroy_swapchain_resources();
+        if let Some(device) = self.device.as_ref() {
+            if let Some(buffer) = self.index_buffer.take() {
+                // SAFETY: Buffer and memory belong to this device and are destroyed once.
+                unsafe {
+                    device.device().destroy_buffer(buffer.buffer, None);
+                    device.device().free_memory(buffer.memory, None);
+                }
+            }
+            if let Some(buffer) = self.vertex_buffer.take() {
+                // SAFETY: Buffer and memory belong to this device and are destroyed once.
+                unsafe {
+                    device.device().destroy_buffer(buffer.buffer, None);
+                    device.device().free_memory(buffer.memory, None);
+                }
+            }
+            // SAFETY: The command pool belongs to this device and is destroyed once after buffers are freed.
+            unsafe {
+                device
+                    .device()
+                    .destroy_command_pool(self.command_pool, None);
+            };
+            // SAFETY: The logical device remains live until the renderer completes teardown.
+            let _ = unsafe { device.device().device_wait_idle() };
+        }
+        self.swapchain.take();
+        self.device.take();
+        self.surface.take();
+        self.validation.take();
+        self.instance.take();
+    }
+}
+
+fn create_validation_messenger(
+    instance: &VulkanInstanceProbe,
+) -> Result<VulkanValidationMessenger, VulkanSmokeRendererError> {
+    let shared = Box::new(VulkanValidationShared::default());
+    let loader = ash::ext::debug_utils::Instance::new(&instance.entry, &instance.instance);
+    let create_info = vk::DebugUtilsMessengerCreateInfoEXT::default()
+        .message_severity(
+            vk::DebugUtilsMessageSeverityFlagsEXT::WARNING
+                | vk::DebugUtilsMessageSeverityFlagsEXT::ERROR,
+        )
+        .message_type(
+            vk::DebugUtilsMessageTypeFlagsEXT::GENERAL
+                | vk::DebugUtilsMessageTypeFlagsEXT::VALIDATION
+                | vk::DebugUtilsMessageTypeFlagsEXT::PERFORMANCE,
+        )
+        .pfn_user_callback(Some(vulkan_validation_callback))
+        .user_data((&raw const *shared).cast_mut().cast());
+    let messenger =
+        // SAFETY: The create info points at a stable boxed user-data allocation for the messenger lifetime.
+        unsafe { loader.create_debug_utils_messenger(&create_info, None) }.map_err(|error| {
+            VulkanSmokeRendererError::VulkanOperation {
+                context: "vkCreateDebugUtilsMessengerEXT",
+                result: format!("{error:?}"),
+            }
+        })?;
+    Ok(VulkanValidationMessenger {
+        loader,
+        messenger,
+        shared,
+    })
+}
+
+fn create_command_pool(
+    device: &VulkanLogicalDeviceProbe,
+) -> Result<vk::CommandPool, VulkanSmokeRendererError> {
+    let create_info = vk::CommandPoolCreateInfo::default()
+        .queue_family_index(device.report.graphics_queue_family)
+        .flags(vk::CommandPoolCreateFlags::RESET_COMMAND_BUFFER);
+    // SAFETY: The queue-family index belongs to this live logical device.
+    unsafe { device.device().create_command_pool(&create_info, None) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context: "vkCreateCommandPool",
+            result: format!("{error:?}"),
+        }
+    })
+}
+
+fn create_triangle_vertex_buffer(
+    instance: &VulkanInstanceProbe,
+    device: &VulkanLogicalDeviceProbe,
+) -> Result<VulkanAllocatedBuffer, VulkanSmokeRendererError> {
+    let vertices: [[f32; 5]; 3] = [
+        [0.0, -0.55, 1.0, 0.2, 0.2],
+        [0.55, 0.55, 0.2, 1.0, 0.2],
+        [-0.55, 0.55, 0.2, 0.4, 1.0],
+    ];
+    let mut bytes = Vec::with_capacity(vertices.len() * 5 * std::mem::size_of::<f32>());
+    for vertex in vertices {
+        for value in vertex {
+            bytes.extend_from_slice(&value.to_ne_bytes());
+        }
+    }
+    create_host_visible_buffer(
+        instance,
+        device,
+        &bytes,
+        vk::BufferUsageFlags::VERTEX_BUFFER,
+        "triangle vertex buffer",
+    )
+}
+
+fn create_triangle_index_buffer(
+    instance: &VulkanInstanceProbe,
+    device: &VulkanLogicalDeviceProbe,
+) -> Result<VulkanAllocatedBuffer, VulkanSmokeRendererError> {
+    let indices = [0_u16, 1_u16, 2_u16];
+    let mut bytes = Vec::with_capacity(indices.len() * std::mem::size_of::<u16>());
+    for index in indices {
+        bytes.extend_from_slice(&index.to_ne_bytes());
+    }
+    create_host_visible_buffer(
+        instance,
+        device,
+        &bytes,
+        vk::BufferUsageFlags::INDEX_BUFFER,
+        "triangle index buffer",
+    )
+}
+
+fn create_host_visible_buffer(
+    instance: &VulkanInstanceProbe,
+    device: &VulkanLogicalDeviceProbe,
+    bytes: &[u8],
+    usage: vk::BufferUsageFlags,
+    context: &'static str,
+) -> Result<VulkanAllocatedBuffer, VulkanSmokeRendererError> {
+    let create_info = vk::BufferCreateInfo::default()
+        .size(bytes.len().try_into().unwrap_or(u64::MAX))
+        .usage(usage)
+        .sharing_mode(vk::SharingMode::EXCLUSIVE);
+    // SAFETY: The create info is stack-owned and references no external memory.
+    let buffer = unsafe { device.device().create_buffer(&create_info, None) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context,
+            result: format!("{error:?}"),
+        }
+    })?;
+    // SAFETY: The buffer belongs to this device and is queried immediately after creation.
+    let requirements = unsafe { device.device().get_buffer_memory_requirements(buffer) };
+    let memory_type_index = find_memory_type(
+        instance,
+        device.physical_device,
+        requirements.memory_type_bits,
+        vk::MemoryPropertyFlags::HOST_VISIBLE | vk::MemoryPropertyFlags::HOST_COHERENT,
+    )
+    .ok_or(VulkanSmokeRendererError::MissingMemoryType { context })?;
+    let allocate_info = vk::MemoryAllocateInfo::default()
+        .allocation_size(requirements.size)
+        .memory_type_index(memory_type_index);
+    let memory =
+        // SAFETY: Allocation uses a memory type index selected from the physical-device requirements above.
+        unsafe { device.device().allocate_memory(&allocate_info, None) }.map_err(|error| {
+            VulkanSmokeRendererError::VulkanOperation {
+                context,
+                result: format!("{error:?}"),
+            }
+        })?;
+    // SAFETY: The buffer and allocation belong to the same live logical device.
+    unsafe { device.device().bind_buffer_memory(buffer, memory, 0) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context,
+            result: format!("{error:?}"),
+        }
+    })?;
+    // SAFETY: The allocation is HOST_VISIBLE, mapped for the full buffer size and unmapped before return.
+    let mapped = unsafe {
+        device
+            .device()
+            .map_memory(memory, 0, requirements.size, vk::MemoryMapFlags::empty())
+    }
+    .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+        context,
+        result: format!("{error:?}"),
+    })?;
+    // SAFETY: The mapped pointer is valid for `bytes.len()` bytes and non-overlapping with the source slice.
+    unsafe {
+        std::ptr::copy_nonoverlapping(bytes.as_ptr(), mapped.cast::<u8>(), bytes.len());
+        device.device().unmap_memory(memory);
+    }
+    Ok(VulkanAllocatedBuffer { buffer, memory })
+}
+
+fn find_memory_type(
+    instance: &VulkanInstanceProbe,
+    physical_device: vk::PhysicalDevice,
+    memory_type_bits: u32,
+    required_properties: vk::MemoryPropertyFlags,
+) -> Option<u32> {
+    // SAFETY: Physical-device memory properties are queried from a live instance-owned physical device.
+    let memory_properties = unsafe {
+        instance
+            .instance
+            .get_physical_device_memory_properties(physical_device)
+    };
+    memory_properties
+        .memory_types
+        .iter()
+        .enumerate()
+        .find_map(|(index, memory_type)| {
+            let supported = (memory_type_bits & (1_u32 << index)) != 0;
+            let has_properties = memory_type.property_flags.contains(required_properties);
+            (supported && has_properties).then(|| index.try_into().unwrap_or(u32::MAX))
+        })
+}
+
+fn create_swapchain_resources(
+    device: &VulkanLogicalDeviceProbe,
+    swapchain: &VulkanSwapchainProbe,
+    command_pool: vk::CommandPool,
+    _vertex_buffer: &VulkanAllocatedBuffer,
+    _index_buffer: &VulkanAllocatedBuffer,
+    _reuse_command_pool: bool,
+) -> Result<VulkanSwapchainResources, VulkanSmokeRendererError> {
+    // SAFETY: The swapchain is live and owned by this renderer for the duration of the query.
+    let images = unsafe {
+        swapchain
+            .loader()
+            .get_swapchain_images(swapchain.swapchain())
+    }
+    .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+        context: "vkGetSwapchainImagesKHR",
+        result: format!("{error:?}"),
+    })?;
+    let image_views = images
+        .iter()
+        .map(|image| create_image_view(device, *image, swapchain.report.plan.format.format))
+        .collect::<Result<Vec<_>, _>>()?;
+    let render_pass = create_render_pass(device, swapchain.report.plan.format.format)?;
+    let pipeline_layout = create_pipeline_layout(device)?;
+    let pipeline = create_graphics_pipeline(
+        device,
+        render_pass,
+        pipeline_layout,
+        swapchain.report.plan.extent,
+    )?;
+    let framebuffers = image_views
+        .iter()
+        .map(|image_view| {
+            create_framebuffer(
+                device,
+                render_pass,
+                *image_view,
+                swapchain.report.plan.extent,
+            )
+        })
+        .collect::<Result<Vec<_>, _>>()?;
+    let command_buffers = allocate_command_buffers(
+        device,
+        command_pool,
+        image_views.len().try_into().unwrap_or(u32::MAX),
+    )?;
+    Ok(VulkanSwapchainResources {
+        image_views,
+        render_pass,
+        pipeline_layout,
+        pipeline,
+        framebuffers,
+        command_buffers,
+    })
+}
+
+fn create_image_view(
+    device: &VulkanLogicalDeviceProbe,
+    image: vk::Image,
+    format: i32,
+) -> Result<vk::ImageView, VulkanSmokeRendererError> {
+    let create_info = vk::ImageViewCreateInfo::default()
+        .image(image)
+        .view_type(vk::ImageViewType::TYPE_2D)
+        .format(vk::Format::from_raw(format))
+        .subresource_range(color_subresource_range());
+    // SAFETY: The image comes from the live swapchain and the subresource range covers its color aspect.
+    unsafe { device.device().create_image_view(&create_info, None) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context: "vkCreateImageView",
+            result: format!("{error:?}"),
+        }
+    })
+}
+
+fn create_render_pass(
+    device: &VulkanLogicalDeviceProbe,
+    format: i32,
+) -> Result<vk::RenderPass, VulkanSmokeRendererError> {
+    let color_attachment = vk::AttachmentDescription::default()
+        .format(vk::Format::from_raw(format))
+        .samples(vk::SampleCountFlags::TYPE_1)
+        .load_op(vk::AttachmentLoadOp::CLEAR)
+        .store_op(vk::AttachmentStoreOp::STORE)
+        .initial_layout(vk::ImageLayout::COLOR_ATTACHMENT_OPTIMAL)
+        .final_layout(vk::ImageLayout::COLOR_ATTACHMENT_OPTIMAL);
+    let color_attachment_ref = vk::AttachmentReference::default()
+        .attachment(0)
+        .layout(vk::ImageLayout::COLOR_ATTACHMENT_OPTIMAL);
+    let color_attachments = [color_attachment_ref];
+    let subpass = vk::SubpassDescription::default()
+        .pipeline_bind_point(vk::PipelineBindPoint::GRAPHICS)
+        .color_attachments(&color_attachments);
+    let dependency = vk::SubpassDependency::default()
+        .src_subpass(vk::SUBPASS_EXTERNAL)
+        .dst_subpass(0)
+        .src_stage_mask(vk::PipelineStageFlags::COLOR_ATTACHMENT_OUTPUT)
+        .dst_stage_mask(vk::PipelineStageFlags::COLOR_ATTACHMENT_OUTPUT)
+        .dst_access_mask(vk::AccessFlags::COLOR_ATTACHMENT_WRITE);
+    let attachments = [color_attachment];
+    let subpasses = [subpass];
+    let dependencies = [dependency];
+    let create_info = vk::RenderPassCreateInfo::default()
+        .attachments(&attachments)
+        .subpasses(&subpasses)
+        .dependencies(&dependencies);
+    // SAFETY: The render-pass create info only references stack-owned descriptors.
+    unsafe { device.device().create_render_pass(&create_info, None) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context: "vkCreateRenderPass",
+            result: format!("{error:?}"),
+        }
+    })
+}
+
+fn create_pipeline_layout(
+    device: &VulkanLogicalDeviceProbe,
+) -> Result<vk::PipelineLayout, VulkanSmokeRendererError> {
+    let create_info = vk::PipelineLayoutCreateInfo::default();
+    // SAFETY: The pipeline layout contains no descriptor sets or push constants.
+    unsafe { device.device().create_pipeline_layout(&create_info, None) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context: "vkCreatePipelineLayout",
+            result: format!("{error:?}"),
+        }
+    })
+}
+
+fn extent_component_to_f32(value: u32) -> f32 {
+    u16::try_from(value).map_or(f32::from(u16::MAX), f32::from)
+}
+
+fn create_graphics_pipeline(
+    device: &VulkanLogicalDeviceProbe,
+    render_pass: vk::RenderPass,
+    pipeline_layout: vk::PipelineLayout,
+    extent: (u32, u32),
+) -> Result<vk::Pipeline, VulkanSmokeRendererError> {
+    let entry_point = c"main";
+    let vertex_module = create_shader_module(device, TRIANGLE_VERTEX_SHADER_WORDS)?;
+    let fragment_module = create_shader_module(device, TRIANGLE_FRAGMENT_SHADER_WORDS)?;
+    let stage_create_infos = [
+        vk::PipelineShaderStageCreateInfo::default()
+            .stage(vk::ShaderStageFlags::VERTEX)
+            .module(vertex_module)
+            .name(entry_point),
+        vk::PipelineShaderStageCreateInfo::default()
+            .stage(vk::ShaderStageFlags::FRAGMENT)
+            .module(fragment_module)
+            .name(entry_point),
+    ];
+    let binding_descriptions = [vk::VertexInputBindingDescription {
+        binding: 0,
+        stride: 20,
+        input_rate: vk::VertexInputRate::VERTEX,
+    }];
+    let attribute_descriptions = [
+        vk::VertexInputAttributeDescription {
+            location: 0,
+            binding: 0,
+            format: vk::Format::R32G32_SFLOAT,
+            offset: 0,
+        },
+        vk::VertexInputAttributeDescription {
+            location: 1,
+            binding: 0,
+            format: vk::Format::R32G32B32_SFLOAT,
+            offset: 8,
+        },
+    ];
+    let vertex_input_state = vk::PipelineVertexInputStateCreateInfo::default()
+        .vertex_binding_descriptions(&binding_descriptions)
+        .vertex_attribute_descriptions(&attribute_descriptions);
+    let input_assembly_state = vk::PipelineInputAssemblyStateCreateInfo::default()
+        .topology(vk::PrimitiveTopology::TRIANGLE_LIST);
+    let viewports = [vk::Viewport {
+        x: 0.0,
+        y: 0.0,
+        width: extent_component_to_f32(extent.0),
+        height: extent_component_to_f32(extent.1),
+        min_depth: 0.0,
+        max_depth: 1.0,
+    }];
+    let scissors = [vk::Rect2D {
+        offset: vk::Offset2D { x: 0, y: 0 },
+        extent: vk::Extent2D {
+            width: extent.0,
+            height: extent.1,
+        },
+    }];
+    let viewport_state = vk::PipelineViewportStateCreateInfo::default()
+        .viewports(&viewports)
+        .scissors(&scissors);
+    let rasterization_state = vk::PipelineRasterizationStateCreateInfo::default()
+        .polygon_mode(vk::PolygonMode::FILL)
+        .cull_mode(vk::CullModeFlags::BACK)
+        .front_face(vk::FrontFace::CLOCKWISE)
+        .line_width(1.0);
+    let multisample_state = vk::PipelineMultisampleStateCreateInfo::default()
+        .rasterization_samples(vk::SampleCountFlags::TYPE_1);
+    let color_blend_attachment = [vk::PipelineColorBlendAttachmentState::default()
+        .color_write_mask(
+            vk::ColorComponentFlags::R
+                | vk::ColorComponentFlags::G
+                | vk::ColorComponentFlags::B
+                | vk::ColorComponentFlags::A,
+        )];
+    let color_blend_state =
+        vk::PipelineColorBlendStateCreateInfo::default().attachments(&color_blend_attachment);
+    let create_info = [vk::GraphicsPipelineCreateInfo::default()
+        .stages(&stage_create_infos)
+        .vertex_input_state(&vertex_input_state)
+        .input_assembly_state(&input_assembly_state)
+        .viewport_state(&viewport_state)
+        .rasterization_state(&rasterization_state)
+        .multisample_state(&multisample_state)
+        .color_blend_state(&color_blend_state)
+        .layout(pipeline_layout)
+        .render_pass(render_pass)
+        .subpass(0)];
+    // SAFETY: The pipeline creation references live shader modules and stack-owned fixed-function descriptors.
+    let pipeline = unsafe {
+        device
+            .device()
+            .create_graphics_pipelines(vk::PipelineCache::null(), &create_info, None)
+    }
+    .map_err(|(_, error)| VulkanSmokeRendererError::VulkanOperation {
+        context: "vkCreateGraphicsPipelines",
+        result: format!("{error:?}"),
+    })?[0];
+    // SAFETY: Shader modules are no longer needed after pipeline creation completes.
+    unsafe {
+        device.device().destroy_shader_module(vertex_module, None);
+        device.device().destroy_shader_module(fragment_module, None);
+    }
+    Ok(pipeline)
+}
+
+fn create_shader_module(
+    device: &VulkanLogicalDeviceProbe,
+    words: &[u32],
+) -> Result<vk::ShaderModule, VulkanSmokeRendererError> {
+    let create_info = vk::ShaderModuleCreateInfo::default().code(words);
+    // SAFETY: SPIR-V words are immutable and valid for the duration of the call.
+    unsafe { device.device().create_shader_module(&create_info, None) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context: "vkCreateShaderModule",
+            result: format!("{error:?}"),
+        }
+    })
+}
+
+fn create_framebuffer(
+    device: &VulkanLogicalDeviceProbe,
+    render_pass: vk::RenderPass,
+    image_view: vk::ImageView,
+    extent: (u32, u32),
+) -> Result<vk::Framebuffer, VulkanSmokeRendererError> {
+    let attachments = [image_view];
+    let create_info = vk::FramebufferCreateInfo::default()
+        .render_pass(render_pass)
+        .attachments(&attachments)
+        .width(extent.0)
+        .height(extent.1)
+        .layers(1);
+    // SAFETY: The framebuffer attachments and render pass remain live for the duration of the call.
+    unsafe { device.device().create_framebuffer(&create_info, None) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context: "vkCreateFramebuffer",
+            result: format!("{error:?}"),
+        }
+    })
+}
+
+fn allocate_command_buffers(
+    device: &VulkanLogicalDeviceProbe,
+    command_pool: vk::CommandPool,
+    count: u32,
+) -> Result<Vec<vk::CommandBuffer>, VulkanSmokeRendererError> {
+    let allocate_info = vk::CommandBufferAllocateInfo::default()
+        .command_pool(command_pool)
+        .level(vk::CommandBufferLevel::PRIMARY)
+        .command_buffer_count(count);
+    // SAFETY: Command buffers are allocated from a live resettable pool owned by this device.
+    unsafe { device.device().allocate_command_buffers(&allocate_info) }.map_err(|error| {
+        VulkanSmokeRendererError::VulkanOperation {
+            context: "vkAllocateCommandBuffers",
+            result: format!("{error:?}"),
+        }
+    })
+}
+
+fn create_frame_sync(
+    device: &VulkanLogicalDeviceProbe,
+) -> Result<Vec<VulkanFrameSync>, VulkanSmokeRendererError> {
+    let semaphore_info = vk::SemaphoreCreateInfo::default();
+    let fence_info = vk::FenceCreateInfo::default().flags(vk::FenceCreateFlags::SIGNALED);
+    let mut sync = Vec::with_capacity(2);
+    for _ in 0..2 {
+        // SAFETY: The sync objects belong to this live logical device and are destroyed at teardown.
+        let image_available = unsafe { device.device().create_semaphore(&semaphore_info, None) }
+            .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+                context: "vkCreateSemaphore(image_available)",
+                result: format!("{error:?}"),
+            })?;
+        // SAFETY: The sync objects belong to this live logical device and are destroyed at teardown.
+        let render_finished = unsafe { device.device().create_semaphore(&semaphore_info, None) }
+            .map_err(|error| VulkanSmokeRendererError::VulkanOperation {
+                context: "vkCreateSemaphore(render_finished)",
+                result: format!("{error:?}"),
+            })?;
+        let fence =
+            // SAFETY: The fence belongs to this live logical device and is destroyed at teardown.
+            unsafe { device.device().create_fence(&fence_info, None) }.map_err(|error| {
+                VulkanSmokeRendererError::VulkanOperation {
+                    context: "vkCreateFence",
+                    result: format!("{error:?}"),
+                }
+            })?;
+        sync.push(VulkanFrameSync {
+            image_available,
+            render_finished,
+            fence,
+        });
+    }
+    Ok(sync)
+}
+
+fn destroy_swapchain_resources(
+    device: &VulkanLogicalDeviceProbe,
+    command_pool: vk::CommandPool,
+    resources: VulkanSwapchainResources,
+) {
+    // SAFETY: All swapchain-dependent objects belong to this device and are destroyed once.
+    unsafe {
+        device
+            .device()
+            .free_command_buffers(command_pool, &resources.command_buffers);
+        for framebuffer in resources.framebuffers {
+            device.device().destroy_framebuffer(framebuffer, None);
+        }
+        device.device().destroy_pipeline(resources.pipeline, None);
+        device
+            .device()
+            .destroy_pipeline_layout(resources.pipeline_layout, None);
+        device
+            .device()
+            .destroy_render_pass(resources.render_pass, None);
+        for image_view in resources.image_views {
+            device.device().destroy_image_view(image_view, None);
+        }
+    }
+}
+
+fn color_subresource_range() -> vk::ImageSubresourceRange {
+    vk::ImageSubresourceRange::default()
+        .aspect_mask(vk::ImageAspectFlags::COLOR)
+        .base_mip_level(0)
+        .level_count(1)
+        .base_array_layer(0)
+        .layer_count(1)
+}
+
 /// Runtime swapchain creation report.
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct VulkanSwapchainReport {
@@ -879,6 +2585,28 @@ pub fn create_vulkan_swapchain_probe(
     surface: &VulkanSurfaceProbe,
     device: &VulkanLogicalDeviceProbe,
 ) -> Result<VulkanSwapchainProbe, VulkanSwapchainProbeError> {
+    create_vulkan_swapchain_probe_for_extent(
+        instance,
+        surface,
+        device,
+        device.runtime.swapchain.extent,
+        vk::SwapchainKHR::null(),
+    )
+}
+
+/// Creates a Vulkan swapchain for the live logical device and surface at a specific extent.
+///
+/// # Errors
+///
+/// Returns [`VulkanSwapchainProbeError`] when live surface capability queries,
+/// swapchain creation, or swapchain image enumeration fails.
+pub fn create_vulkan_swapchain_probe_for_extent(
+    instance: &VulkanInstanceProbe,
+    surface: &VulkanSurfaceProbe,
+    device: &VulkanLogicalDeviceProbe,
+    drawable_extent: (u32, u32),
+    old_swapchain: vk::SwapchainKHR,
+) -> Result<VulkanSwapchainProbe, VulkanSwapchainProbeError> {
     let raw_capabilities = {
         // SAFETY: The physical device and surface are live query inputs and no handles are retained.
         unsafe {
@@ -892,7 +2620,35 @@ pub fn create_vulkan_swapchain_probe(
             result: format!("{error:?}"),
         },
     )?;
-    let plan = &device.runtime.swapchain;
+    let surface_formats =
+        live_surface_formats(surface, device.physical_device, &device.report.device_name).map_err(
+            |error| VulkanSwapchainProbeError::CreateFailed {
+                result: error.to_string(),
+            },
+        )?;
+    let present_modes =
+        live_present_modes(surface, device.physical_device, &device.report.device_name).map_err(
+            |error| VulkanSwapchainProbeError::CreateFailed {
+                result: error.to_string(),
+            },
+        )?;
+    let capabilities =
+        live_surface_capabilities(surface, device.physical_device, &device.report.device_name)
+            .map_err(
+                |error| VulkanSwapchainProbeError::SurfaceCapabilitiesFailed {
+                    result: error.to_string(),
+                },
+            )?;
+    let plan = plan_vulkan_swapchain(&VulkanSwapchainRequest {
+        drawable_extent,
+        formats: surface_formats,
+        present_modes,
+        capabilities,
+        preferred_present_mode: vk::PresentModeKHR::MAILBOX.as_raw(),
+    })
+    .map_err(|error| VulkanSwapchainProbeError::CreateFailed {
+        result: error.to_string(),
+    })?;
     let queue_family_indices = unique_queue_families(
         device.runtime.capability.graphics_queue_family,
         device.runtime.capability.present_queue_family,
@@ -920,6 +2676,7 @@ pub fn create_vulkan_swapchain_probe(
             raw_capabilities.supported_composite_alpha,
         ))
         .present_mode(vk::PresentModeKHR::from_raw(plan.present_mode))
+        .old_swapchain(old_swapchain)
         .clipped(true);
     let loader = swapchain::Device::new(&instance.instance, &device.device);
     // SAFETY: The create info references live instance/device/surface handles for this call.
@@ -939,7 +2696,7 @@ pub fn create_vulkan_swapchain_probe(
         swapchain,
         report: VulkanSwapchainReport {
             schema: 1,
-            plan: plan.clone(),
+            plan,
             image_count: images.len().try_into().unwrap_or(u32::MAX),
         },
     })
@@ -959,8 +2716,15 @@ 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 = live_device_candidate(instance, surface, device, index)?;
+        let candidate = match live_device_candidate(instance, surface, device, index) {
+            Ok(candidate) => candidate,
+            Err(err) => {
+                last_error = Some(err);
+                continue;
+            }
+        };
         match &best {
             Some(existing)
                 if compare_reports(&candidate.capability, &existing.capability)
@@ -968,9 +2732,11 @@ fn select_live_device_candidate(
             _ => best = Some(candidate),
         }
     }
-    let best = best.ok_or(VulkanRuntimeCapabilityError::Capability(
-        VulkanCapabilityError::NoPhysicalDevice,
-    ))?;
+    let best = best.ok_or_else(|| {
+        last_error.unwrap_or(VulkanRuntimeCapabilityError::Capability(
+            VulkanCapabilityError::NoPhysicalDevice,
+        ))
+    })?;
     let swapchain = plan_vulkan_swapchain(&VulkanSwapchainRequest {
         drawable_extent,
         formats: best.surface_formats,
@@ -1259,6 +3025,8 @@ pub enum VulkanInstanceError {
         /// Invalid extension name.
         extension: String,
     },
+    /// Validation layers were requested but unavailable.
+    MissingValidationLayer,
     /// Instance creation failed.
     CreateFailed {
         /// Vulkan result.
@@ -1279,6 +3047,12 @@ impl std::fmt::Display for VulkanInstanceError {
                     "Vulkan instance extension name contains an interior NUL byte: {extension:?}"
                 )
             }
+            Self::MissingValidationLayer => {
+                write!(
+                    f,
+                    "Vulkan validation layer VK_LAYER_KHRONOS_validation is unavailable"
+                )
+            }
             Self::CreateFailed { result } => write!(f, "Vulkan instance creation failed: {result}"),
         }
     }
@@ -1290,6 +3064,13 @@ impl std::error::Error for VulkanInstanceError {}
 #[must_use]
 pub fn plan_vulkan_instance(config: &VulkanInstanceConfig) -> VulkanInstancePlan {
     let mut enabled_extensions = config.required_extensions.clone();
+    if config.enable_validation
+        && !enabled_extensions
+            .iter()
+            .any(|extension| extension == EXT_DEBUG_UTILS_EXTENSION)
+    {
+        enabled_extensions.push(EXT_DEBUG_UTILS_EXTENSION.to_string());
+    }
     if config.enable_portability_enumeration
         && !enabled_extensions
             .iter()
@@ -1332,6 +3113,8 @@ pub fn create_vulkan_instance_probe(
     let plan = plan_vulkan_instance(config);
     let extension_names = cstring_vec(&plan.enabled_extensions)?;
     let extension_ptrs = cstring_ptrs(&extension_names);
+    let layer_names = validation_layer_cstrings(&entry, config.enable_validation)?;
+    let layer_ptrs = cstring_ptrs(&layer_names);
     let app_info = vk::ApplicationInfo::default()
         .application_name(&app_name)
         .application_version(0)
@@ -1341,6 +3124,7 @@ pub fn create_vulkan_instance_probe(
     let create_info = vk::InstanceCreateInfo::default()
         .application_info(&app_info)
         .enabled_extension_names(&extension_ptrs)
+        .enabled_layer_names(&layer_ptrs)
         .flags(vk::InstanceCreateFlags::from_raw(plan.create_flags));
     // SAFETY: `create_info` points to stack-owned Vulkan create data that lives for the call.
     let instance = unsafe { entry.create_instance(&create_info, None) }.map_err(|error| {
@@ -1355,6 +3139,35 @@ pub fn create_vulkan_instance_probe(
     })
 }
 
+fn validation_layer_cstrings(
+    entry: &ash::Entry,
+    enable_validation: bool,
+) -> Result<Vec<CString>, VulkanInstanceError> {
+    if !enable_validation {
+        return Ok(Vec::new());
+    }
+    let available_layers =
+        // SAFETY: Enumerating instance layers reads loader-owned immutable metadata.
+        unsafe { entry.enumerate_instance_layer_properties() }.map_err(|error| {
+            VulkanInstanceError::CreateFailed {
+                result: format!("{error:?}"),
+            }
+        })?;
+    let validation_available = available_layers.iter().any(|layer| {
+        // SAFETY: Vulkan layer names are fixed-size NUL-terminated strings from the loader.
+        unsafe { CStr::from_ptr(layer.layer_name.as_ptr()) }
+            .to_string_lossy()
+            .as_ref()
+            == VALIDATION_LAYER_NAME
+    });
+    if !validation_available {
+        return Err(VulkanInstanceError::MissingValidationLayer);
+    }
+    Ok(vec![CString::new(VALIDATION_LAYER_NAME).map_err(|_| {
+        VulkanInstanceError::InvalidApplicationName
+    })?])
+}
+
 /// Renders a deterministic JSON Vulkan instance plan.
 #[must_use]
 pub fn render_instance_plan_json(plan: &VulkanInstancePlan) -> String {
@@ -1901,15 +3714,22 @@ pub fn select_physical_device(
     }
 
     let mut best = None;
+    let mut last_error = None;
     for device in devices {
-        let report = validate_device(device)?;
+        let report = match validate_device(device) {
+            Ok(report) => report,
+            Err(err) => {
+                last_error = Some(err);
+                continue;
+            }
+        };
         match &best {
             Some(existing) if compare_reports(&report, existing) != std::cmp::Ordering::Greater => {
             }
             _ => best = Some(report),
         }
     }
-    best.ok_or(VulkanCapabilityError::NoPhysicalDevice)
+    best.ok_or_else(|| last_error.unwrap_or(VulkanCapabilityError::NoPhysicalDevice))
 }
 
 /// Builds a deterministic swapchain plan from surface capabilities.
@@ -2072,22 +3892,7 @@ fn validate_device(
             device: device.name.clone(),
         });
     }
-    let graphics_queue_family = device
-        .queue_families
-        .iter()
-        .find(|family| family.graphics)
-        .ok_or_else(|| VulkanCapabilityError::NoGraphicsQueue {
-            device: device.name.clone(),
-        })?
-        .index;
-    let present_queue_family = device
-        .queue_families
-        .iter()
-        .find(|family| family.present)
-        .ok_or_else(|| VulkanCapabilityError::NoPresentQueue {
-            device: device.name.clone(),
-        })?
-        .index;
+    let (graphics_queue_family, present_queue_family) = select_queue_families(device)?;
 
     let portability_subset = device.supports_extension(KHR_PORTABILITY_SUBSET_EXTENSION);
     let mut enabled_extensions = vec![KHR_SWAPCHAIN_EXTENSION.to_string()];
@@ -2107,6 +3912,36 @@ fn validate_device(
     })
 }
 
+fn select_queue_families(
+    device: &VulkanPhysicalDeviceRecord,
+) -> Result<(u32, u32), VulkanCapabilityError> {
+    if let Some(unified) = device
+        .queue_families
+        .iter()
+        .find(|family| family.graphics && family.present)
+    {
+        return Ok((unified.index, unified.index));
+    }
+
+    let graphics_queue_family = device
+        .queue_families
+        .iter()
+        .find(|family| family.graphics)
+        .ok_or_else(|| VulkanCapabilityError::NoGraphicsQueue {
+            device: device.name.clone(),
+        })?
+        .index;
+    let present_queue_family = device
+        .queue_families
+        .iter()
+        .find(|family| family.present)
+        .ok_or_else(|| VulkanCapabilityError::NoPresentQueue {
+            device: device.name.clone(),
+        })?
+        .index;
+    Ok((graphics_queue_family, present_queue_family))
+}
+
 fn score_device(
     device: &VulkanPhysicalDeviceRecord,
     graphics_queue_family: u32,
@@ -2266,9 +4101,9 @@ fn push_json_string(out: &mut String, value: &str) {
     out.push('"');
 }
 
-/// Diagnostics for Vulkan backend setup and frame progression.
+/// Diagnostics for Vulkan planning backend setup and frame progression.
 #[derive(Clone, Debug, PartialEq)]
-pub struct VulkanBackendReport {
+pub struct VulkanPlanningBackendReport {
     /// Unix time at initialization.
     pub initialized_at: u64,
     /// Total frames executed.
@@ -2287,7 +4122,7 @@ pub struct VulkanBackendReport {
     pub last_frame_submission: Option<VulkanFrameSubmissionPlan>,
 }
 
-impl Default for VulkanBackendReport {
+impl Default for VulkanPlanningBackendReport {
     fn default() -> Self {
         Self {
             initialized_at: SystemTime::now()
@@ -2304,27 +4139,27 @@ impl Default for VulkanBackendReport {
     }
 }
 
-/// Vulkan backend façade used by the game entrypoint.
+/// Vulkan planning backend façade used by the game entrypoint.
 #[derive(Debug)]
-pub struct VulkanBackend {
+pub struct VulkanPlanningBackend {
     state: VulkanBackendState,
-    report: VulkanBackendReport,
+    report: VulkanPlanningBackendReport,
     swapchain_plan: VulkanSwapchainPlan,
 }
 
-impl Default for VulkanBackend {
+impl Default for VulkanPlanningBackend {
     fn default() -> Self {
         Self::new()
     }
 }
 
-impl VulkanBackend {
-    /// Creates a new Vulkan-backed backend façade.
+impl VulkanPlanningBackend {
+    /// Creates a new Vulkan planning backend façade.
     #[must_use]
     pub fn new() -> Self {
         Self {
             state: VulkanBackendState::Ready,
-            report: VulkanBackendReport::default(),
+            report: VulkanPlanningBackendReport::default(),
             swapchain_plan: default_stage0_swapchain_plan(),
         }
     }
@@ -2360,7 +4195,7 @@ impl VulkanBackend {
 
     /// Returns backend report.
     #[must_use]
-    pub fn report(&self) -> &VulkanBackendReport {
+    pub fn report(&self) -> &VulkanPlanningBackendReport {
         &self.report
     }
 
@@ -2369,7 +4204,7 @@ impl VulkanBackend {
     }
 }
 
-impl RenderBackend for VulkanBackend {
+impl RenderBackend for VulkanPlanningBackend {
     fn execute(&mut self, commands: &RenderCommandList) -> Result<FrameOutput, RenderError> {
         if !matches!(
             self.state,
@@ -2410,7 +4245,7 @@ mod tests {
 
     #[test]
     fn backend_tracks_render_request_and_presents() -> Result<(), RenderError> {
-        let mut backend = VulkanBackend::new();
+        let mut backend = VulkanPlanningBackend::new();
         let request = RenderRequest::conservative();
         backend.set_render_request(request);
         assert_eq!(backend.render_request(), request);
@@ -2648,7 +4483,7 @@ mod tests {
 
         assert_eq!(
             render_instance_plan_json(&plan),
-            "{\"schema\":1,\"create_flags\":1,\"validation_requested\":true,\"enabled_extensions\":[\"VK_KHR_portability_enumeration\",\"VK_KHR_surface\"]}"
+            "{\"schema\":1,\"create_flags\":1,\"validation_requested\":true,\"enabled_extensions\":[\"VK_EXT_debug_utils\",\"VK_KHR_portability_enumeration\",\"VK_KHR_surface\"]}"
         );
     }
 
@@ -2794,18 +4629,18 @@ mod tests {
         assert_eq!(report.modules.len(), 2);
         assert_eq!(report.modules[0].name, "triangle.vert");
         assert_eq!(report.modules[0].stage, VulkanShaderStage::Vertex);
-        assert_eq!(report.modules[0].word_count, 12);
+        assert_eq!(report.modules[0].word_count, 253);
         assert_eq!(
             report.modules[0].sha256,
-            "f0dc7b3388e59e94a0e1d5d82c97f103d47ab703145fdf44acb3b7cdf0d6087f"
+            "9023b1cc856c98ecd21755596c4e9d1e62cc63e1787f8c43ada2101544e8d0d1"
         );
         assert_eq!(
             report.modules[1].sha256,
-            "bd5e45e96505076efea674c38214e0ee479030d239b52bdc8ffe9835674d14d5"
+            "6efe2c9716ae845c471ecbaac2c83e56a17a37dc017dd63f0a05f0d9161f44ba"
         );
         assert_eq!(
             report.manifest_hash,
-            "dd293e4ff08ffca1c037900d08b0ffd415db39f238b4fcdde46468fa049b679c"
+            "849ffae9681f5ff2fc145d7b98f19f69b478d9ea73207efdf5f1748e8d51045c"
         );
     }