vkCreateComputePipelines and vkCreateRayTracingPipelinesKHR were passed
VK_NULL_HANDLE, so the driver couldn't reuse compiled shader binaries
across the pipelines built at startup (4 UI shaders + user/RT pipelines)
or across runs.
Add one process-wide Device::pipelineCache. LoadPipelineCache (called
from Initialize) seeds it from pipeline_cache.bin when the file's
VkPipelineCacheHeaderVersionOne header matches this device's
vendorID / deviceID / pipelineCacheUUID; a stale or foreign blob is
discarded so the driver never rejects it. SavePipelineCache is registered
with std::atexit, serialising the cache at process shutdown without any
explicit teardown hook. Both create sites now pass the cache; a null
handle stays valid, so no create-site null check is needed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Two gaps in the Vulkan RT path that fault the device on the NVIDIA
proprietary driver with a non-trivial pipeline (simple VulkanTriangle
never hit them):
1. maxPipelineRayRecursionDepth was hardcoded to 1, so any closest-hit
shader that traces a secondary ray (shadow ray — a very common
pattern) recursed past the pipeline limit (UB → device fault).
PipelineRTVulkan::Init now takes a maxRecursionDepth parameter
(default 1, clamped to the device's maxRayRecursionDepth).
2. The NVIDIA descriptor-heap AS-read workaround rewrites every shader
that reads an accelerationStructureEXT from the heap — including
compute shaders — to read the TLAS device address from a push
constant, but only RTPass pushed that address. A compute shader that
ray-queries the TLAS (rayQueryEXT) therefore ran against an unwritten
push slot → garbage AS handle → VK_ERROR_DEVICE_LOST.
WorkaroundNvidiaAS::Patch now returns a per-shader PatchResult
{patched, tlasPushOffset} instead of writing the clobber-prone global
Device::workaroundTlasPushOffset (removed). VulkanShader stores it;
ShaderBindingTableVulkan/PipelineRTVulkan carry it for RTPass, and
ComputeShader tracks its own offset and pushes the caller-supplied
TLAS address in Dispatch (new defaulted tlasAddress parameter),
mirroring RTPass::Record.
The PushConstantRewrite regression test now asserts Patch's returned
patched/offset and adds two ray-querying compute-shader cases, proving
the rewrite is stage-agnostic and the per-shader offset is correct.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
