The GPU-AV enable list was removed to dodge a crash in SDK 1.4.341,
whose GPU-AV null-deref'd on descriptor_heap pipelines
(VK_PIPELINE_CREATE_2_DESCRIPTOR_HEAP_BIT_EXT, layout = VK_NULL_HANDLE)
in PipelineSubState::GetPipelineLayoutUnion:
https://github.com/KhronosGroup/Vulkan-ValidationLayers/issues/12103
That was fixed in the next SDK release. The validation layer is now
1.4.350 (> 1.4.341), so restore VK_VALIDATION_FEATURE_ENABLE_GPU_ASSISTED_EXT
in the VkValidationFeaturesEXT enable list.
Verified by running the HelloUI example (which draws through the
descriptor_heap compute pipelines) with the layer active: it renders the
full UI for the entire run with GPU-AV reporting "Both GPU Assisted
Validation and Normal Core Check Validation are enabled" and no
descriptor-heap null-deref or VUID errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Reading an acceleration structure through VK_EXT_descriptor_heap aborts
with VK_ERROR_DEVICE_LOST on NVIDIA 610.43.02 — a brand-new-extension
driver fault isolated in #7 (engine setup is correct and validation-clean;
images/buffers through the same heap work, and both traceRayEXT and inline
rayQuery fault identically on the AS read).
An acceleration structure can equally be reached by its device address via
OpConvertUToAccelerationStructureKHR, which reads no descriptor and so never
touches the faulting heap path. glslang has no GLSL spelling for that
conversion, so VulkanShader rewrites the compiled SPIR-V at module-load
time: every `OpLoad %accelStruct <heap-ptr>` becomes a load of the TLAS
device address from a synthesized push-constant block followed by the
convert. RTPass pushes the active frame's TLAS address into that push
constant. User GLSL and example code are unchanged; acceleration structures
still bind into the heap normally.
The workaround is gated on Device::workaroundDescriptorHeapAS (true only on
the NVIDIA proprietary driver) and confined to one fenced block in
Crafter.Graphics-ShaderVulkan.cppm plus the RTPass push and the shaderInt64
feature toggle — delete those once a fixed NVIDIA driver ships and the heap
AS read becomes the direct path again.
Verified: VulkanTriangle ray-traces correctly on native NVIDIA (RTX 4090),
validation-layer-clean, no device loss. The SPIR-V rewrite was independently
validated with spirv-val on both the VulkanTriangle and Sponza raygen
modules.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Two Vulkan validation errors fired on startup of every native (Vulkan)
example, reported in #5:
1. vkCreateDevice enabledLayerCount != 0. Device layers are deprecated
and ignored since Vulkan 1.0; passing them is a spec violation
(VUID-VkDeviceCreateInfo-enabledLayerCount-12384). The device-layer
enumeration/match block in Device::Initialize is removed and
enabledLayerCount is pinned to 0 — layers are enabled at the instance
only.
2. vkQueueSubmit layout transition on a presentable image that "has not
been acquired". StartInit() and RecreateSwapchainAndImages() eagerly
transitioned every swapchain image UNDEFINED -> PRESENT_SRC_KHR before
any vkAcquireNextImageKHR, which the spec forbids (a presentable image
may only be touched after acquire). Those pre-transitions are removed.
Each image's first layout transition now happens lazily in Render(),
after acquire, from UNDEFINED; subsequent frames transition from
PRESENT_SRC_KHR. A per-image `imageInitialised` flag (reset in
CreateSwapchain) selects the correct oldLayout.
Verified under sway (headless, GPU renderer) + VK_LAYER_KHRONOS_validation:
the original code reproduces both errors on HelloUI; the fixed build emits
zero validation messages across initial render and swapchain recreation.
Resolves#5
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
