DescriptorHeapVulkan
- The buffer region started at images * imageDescriptorSize /
bufferDescriptorSize, rounded down. A descriptor_heap array indexes
the heap from byte 0 in strides of its descriptor size, so buffer slot
0 has to sit on a whole buffer descriptor past the images. Where the
image descriptors were not a whole number of buffer descriptors, the
first buffer descriptors overwrote the last image descriptors. Where
they were less than one, the start was bumped to descriptor 1, but the
heap was still sized as if the buffers began right after the images,
so the last buffer descriptors went into the implementation's reserved
range. Every descriptor size is a power of two, so both cases need
image descriptors smaller than buffer descriptors, which NVIDIA (32
and 16 bytes) and llvmpipe (64 and 16) do not have. The start now
rounds up and the heap is sized from it (#163).
- The reserved range sat at a multiple of imageDescriptorAlignment only,
where vkCmdBindResourceHeapEXT also wants bufferDescriptorAlignment
(VUID-vkCmdBindResourceHeapEXT-pBindInfo-11435 and -11436). It now
starts on a multiple of the larger. The buffer descriptors need no more
than the rounding: each alignment is at most its descriptor size, so a
whole number of descriptors is aligned.
- bufferStartElement is 16 bits and took the division unchecked, so an
image region past 65535 buffer descriptors (16384 images on llvmpipe)
wrapped the buffer region around onto the images. Slot counts whose
buffer indices do not fit 16 bits, 0xFFFF being the empty slot, now
throw, naming the counts. A heap without buffer slots has no buffer
region, which starts at 0 as in descriptor-set mode, so image-only
heaps have no index to fit.
- On a driver that reserves nothing (llvmpipe), a heap without sampler
slots was a zero-size buffer, which every Initialize(1, 1, 0) made,
and Window::Render bound its address each frame. Each heap now holds at
least one descriptor, as each binding does in descriptor-set mode. That
grows NVIDIA's sampler heap by one descriptor when no sampler slots are
asked for; the resource heaps of the slot counts in the tree keep their
layouts byte for byte.
- ComputeLayout holds the arithmetic, pure over the descriptor-heap
properties, and Initialize goes through it. GetBufferOffset and
GetBufferOffsetElement, which had their own copies of the old
arithmetic and never had a caller, are gone.
- Bind(cmd, frame) binds a frame's heaps with the reserved ranges
Initialize stored, or in descriptor-set mode the frame's descriptor
set. Window::Render and the RTVolume example worked the reserved-range
offset out from the heap's size with the image-alignment mask, and
call Bind now. The window's per-heap cache of bind structs goes with
it: keyed on the heap pointer, it kept binding the old buffers after a
re-Initialize that reallocated them. The heap still ends with its
reserved range, so code that derives the offset from the size keeps
getting the right one.
Tests
- DescriptorHeapLayout: the issue's two layouts, the reserved range where
buffer descriptors are aligned more strictly than image ones, every
legal combination of descriptor sizes and alignments up to 256 bytes,
no heap empty, the NVIDIA and llvmpipe layouts, the 16-bit limit and
image-only heaps. Pure CPU, no device. Against the old arithmetic it
fails 12 of its 18 checks.
Docs
- README.md's heap bullet and AGENTS.consumer.md say how to bind the
heap outside the frame loop, and the consumer notes that Initialize
throws when buffer indices would pass 16 bits. AGENTS.md lists
ComputeLayout among the functions the pure-logic tests drive.
Closes#163.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
examples/Sponza no longer built natively (#164). Its closest-hit declared a
descriptor_heap sampler2D, which glslang has rejected since c8253623
("Reject descriptor_heap combined image samplers"), and main.cpp wrote it
through VkResourceDescriptorDataEXT::pCombinedImageSampler, which that union
no longer has: the descriptor heap has no combined image samplers. Both went
unnoticed because nothing builds the examples.
Sponza
- closesthit.glsl declares texture2D and sampler heap arrays and joins them
where it samples, as ui-shared.glsl and HeapDynamicIndexHit do. The
sampler slot is a second spec constant beside the image slot, so the
shader assumes nothing about where the host put it, and a constant index
keeps the example running on NVIDIA 610.43.02 (see its README). The
comment no longer says the image slot is offset by bufferStartElement;
only buffer slots are.
- main.cpp gives the heap a sampler slot, writes the albedo as a
SAMPLED_IMAGE from a view create-info, and writes the sampler into the
sampler heap from a VkSamplerCreateInfo with vkWriteSamplerDescriptorsEXT,
as UIRenderer::RegisterSampler does. SamplerVulkan's VkSampler had no use
left. The sampler keeps its linear filtering and repeat addressing and
drops anisotropy, which a hit shader cannot use: it samples at LOD 0,
without derivatives.
Docs
- README.md and examples/Sponza/README.md quote the new declarations, and
the Sponza README says why the texture and the sampler are two
descriptors. Its texture2DArray materials pattern declared a
descriptor_heap sampler2DArray, which glslang rejects as well; it now
joins a texture2DArray and a sampler.
- examples/SponzaBench/README.md drops its caveat that Sponza does not
compile.
Tests
- ExampleShaders compiles every GLSL shader under examples/ with glslang as
crafter-build does for the example (Vulkan rules, SPIR-V 1.4, shaders/ on
the include path, and the descriptor-set build where the example
registers one), so a glslang that starts rejecting one fails a test
rather than an example build nobody runs. It fails on Sponza's old
closest-hit and needs glslang only.
Closes#164.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Examples
- CustomShader did not build for wasm32-wasip1: its DOM branch still set
UICustomBinding::_pad, which 097cc37 (#27) turned into format. The
invalid designator left the bindings array of incomplete type, so the
Load call after it found no overload either. The designator is dropped
rather than renamed, as HDRBloom does: format is 0 for anything but a
StorageTexture binding, and a buffer binding has no texel format to
give. The native branch was never affected.
- Every other example with a DOM path (HelloUI, HelloDom, HDRBloom,
RayQueryPick, RTMultiShadow, RTStress, RTVolume, VulkanTriangle,
Sponza) builds for wasm at this commit. Nothing builds them
otherwise, which is how this one fell behind.
Closes#158.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Device
- Device::Initialize(required, optional) takes DeviceFeatures, the five
core feature structs vulkan10 to vulkan14. The library enables only what
its own shaders and code use. Device::enabledFeatures says what was
enabled, supportedFeatures what the GPU has, apiVersion the version in
use.
- shaderInt16, shaderFloat16, storageBuffer16BitAccess, scalarBlockLayout
and the uniform-buffer, storage-buffer and storage-image non-uniform
indexing bits are no longer enabled for everyone. An application whose
shaders take uint16_t spec constants passes
{.vulkan10 = {.shaderInt16 = VK_TRUE}}. scalarBlockLayout stays on with
the NVIDIA workaround, whose TLAS address may sit in a struct's tail
padding.
- Every GPU is weighed before one is chosen: Vulkan 1.3, the swapchain and,
below 1.4, maintenance5 extensions, the library's needs, the required
features. One that can't run the application is skipped, saying why when
it ranks higher. A CPU device runs it only when nothing else is listed,
and CRAFTER_GRAPHICS_DEVICE never falls back. A GPU two drivers both list
is tried through each.
- When no GPU qualifies, Initialize throws naming each GPU's gaps. It
destroys the instance it made, before any Wayland connection, so it can
be called again asking for less.
- maintenance5 is vulkan14's on a 1.4 GPU and VK_KHR_maintenance5's below.
CRAFTER_GRAPHICS_NO_VULKAN_1_4 runs as a 1.3 application, to exercise
that path on a 1.4 GPU.
- VK_KHR_spirv_1_4 and VK_KHR_shader_float_controls, core since 1.2, are no
longer enabled, nor VK_EXT_shader_atomic_float, which was enabled without
its feature struct. memoryDecompression's feature bit is queried before
it is enabled.
Shaders
- VulkanShader checks a module's capabilities, declared directly or
implicitly, against the enabled core features, the GPU's subgroup
operations and the optional groups, and throws naming the field to pass,
or saying the GPU lacks it. The tables are generated from vk.xml and
SPIR-V's grammar.
- WorkaroundNvidiaAS::Patch sized a row-major matrix push member by its
columns, so the TLAS address could land inside it.
Window
- The swapchain format is one whose own feature flags allow storage reads
and writes without a format, which since Vulkan 1.3 each format says for
itself; shaderStorageImageRead/WriteWithoutFormat are no longer required.
Tests
- DeviceFeatures: ResolveFeatures, ChooseDevice and CheckShaderCapabilities,
without a GPU.
- FeatureRequests: required and optional features end to end, the 1.3
path, and a retry after a refusal.
- PushConstantRewrite: a row-major mat3x4 push member.
- HeapASRead, HeapDynamicIndexHit, RTPassPushData and the ray-tracing
examples ask for the features their shaders use.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Window
- updateInterval runs Update on the window's own clock while the
compositor sends no frame callbacks (hidden, minimized): the Wayland loop
is a poll() loop, and the Win32 loop sleeps until the next update. Both
read the interval each pass.
- SetPresentMode (FIFO, Mailbox, Immediate). A mode the surface lacks, or
whose swapchain has other than numFrames images (Mesa's Mailbox has four),
falls back to FIFO until the mode is set again.
- AddPollFd / RemovePollFd wake the Wayland loop on the app's descriptors.
- The swapchain has TRANSFER_DST where the surface allows it.
- CaptureNextFrame replaces SaveFrame: it records the copy in the frame,
before the present, where SaveFrame read an image already presented. A
frame unwound past before the write still frees the readback buffer.
- Inter-pass barriers on the swapchain image carry the access masks of the
stages the passes use.
Deferred deletion (issue #101)
- VulkanBuffer, Mesh, VulkanShader, ComputeShader and PipelineRTVulkan hand
their handles to the deletion queue from their destructors and moves, as
a frame in flight may still use them; a static owner goes after the
driver has torn down. VulkanShader and PipelineRTVulkan move and can't be
copied; re-Load and re-Init queue the old pipeline.
- The queue and its mutex are never destroyed, and the queue takes handles
from any thread; Device::frameCounter is atomic. Both the queue and the
staging rings count frames as one window renders them (documented).
- DrainDeletions also lets every buffer's staging ring start over: without
a Window nothing else reclaims either, so an app without one calls it
after waiting for its work.
Meshes and buffers
- A Mesh rebuild queues the old acceleration structure and builds into the
same storage after a barrier, so the BLAS address stays put when it fits.
The refit and rebuild barriers cover compute ray queries too.
- RTBuildOptions::noDuplicateAnyHit. Mesh::geometryFlags replaces opaque,
and the refit and rebuild fallbacks keep the flags.
- A re-upload into a buffer a frame in flight may read (UploadDeviceLocal
of the same size, UploadDeviceLocalRange) copies on the GPU, after those
reads, through a per-frame staging ring; on ReBAR it used to write the
buffer in place. Empty uploads record nothing.
- A compressed Mesh::Build that keeps its buffers decompresses into them
after the reads of frames in flight, and the hit shaders and ray queries
wait for the decompress as well as the BLAS build. Its vertex buffer
takes a ranged refit's copies.
- Mesh move-assigns (queueing the BLAS it replaces), so it can be replaced
in place or erased from a vector.
- VulkanBuffer::Create asks for a device address only for buffers with
SHADER_DEVICE_ADDRESS usage, as vkGetBufferDeviceAddress requires; the
others have address 0. UIRenderer::RegisterBuffer refuses those.
- Build inputs are synchronized as shader reads.
Other
- RTPass pushes the app's own push data and traces at an explicit size.
- DescriptorHeapVulkan hands freed slot ranges out again (they leaked), and
keeps its free lists sorted.
- ImageVulkan's mip chain clamps each level to 1 texel: a non-square
image's shorter side went to 0.
- VulkanShader throws on a missing file instead of failing in bad_alloc.
- CRAFTER_GRAPHICS_DEVICE picks the GPU by its number among the distinct
GPUs Vulkan lists; anything but such a number is an error.
- The debug messenger prints info messages only with
CRAFTER_GRAPHICS_VALIDATION set.
- Windows: the WinRT gamepad code moved to a C file (mingw-w64's WinRT
headers don't compile as C++), -lcombase dropped, a reference leak fixed.
- project.cpp honours --local for Crafter.Event, Math and Asset, as Asset
does for Math, and builds every test through one helper, projectArgs
included.
- Tests: DebugMessengerSeverity, DeletionQueueThreads, DeviceSelection,
HeapSlotReuse, MeshLifetime, MipChainNonSquare, PipelineLifetime,
RTPassPushData, SwapchainTransferDst, UploadInFlight, VulkanBufferAddress,
VulkanShaderLifetime, WindowUpdateClock; others extended.
Breaking: SaveFrame is CaptureNextFrame; Mesh::opaque is geometryFlags; a
buffer without SHADER_DEVICE_ADDRESS usage has no address; frameCounter is
std::atomic.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The heap acceleration-structure read still needs the rewrite on
615.78.08; the READMEs say so and point at HeapASRead --no-workaround
for checking a newer driver. Dynamic descriptor indexing in hit shaders
is fixed there, which the README and the Sponza and SponzaBench notes
now say, and the VulkanTriangle investigation no longer contradicts
itself about llvmpipe, which advertises VK_EXT_descriptor_heap now.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Device::Initialize required twelve device extensions with no capability
check. Mesa Turnip (Adreno) lacks six of them: VK_EXT_descriptor_heap,
VK_KHR_shader_untyped_pointers, VK_EXT_device_fault and the three ray
tracing extensions. vkCreateDevice failed there, so not even a UI-only
program could start, although the UI path is compute-only and needs
nothing else that Turnip is missing.
The descriptor heap, ray tracing and device fault are now optional
groups, detected at start-up from the extension list and the feature
bits (Device::descriptorHeapSupported, rayTracingSupported,
deviceFaultSupported). Ray tracing needs the heap; on a device without
it the ray tracing entry points throw a message naming the cause.
Without the heap the same bindless slots live in one update-after-bind
descriptor set per frame, owned by DescriptorHeapVulkan: binding 0
storage images, 1 sampled images, 2 samplers, 3 storage buffers. Slot
allocation, the slot handles, UIDispatchHeader and the UIRenderer API
are unchanged; buffer slots simply stop being offset. Window::Render
binds that frame's set where it binds the heap, every compute pipeline
shares the heap object's pipeline layout, and push data travels as push
constants.
Each UI kernel is built twice from one source. ui-shared.glsl declares
its resources through UI_HEAP_* macros that expand to descriptor_heap
or, with CRAFTER_GRAPHICS_DESCRIPTOR_SETS defined, to set/binding.
<name>.comp.spv and <name>.comp.sets.spv ship side by side and
ComputeShader::Load picks one. The heap build of every shader is
byte-identical to before.
Breaking:
- ComputeShader::Load takes the heap as a second argument.
- DescriptorHeapVulkan is no longer copyable or movable.
- Custom UI shaders declare heap resources with the UI_HEAP_* macros
and are registered twice in project.cpp (see the README).
- project.cpp uses Shader::defines and Shader::variant, so it needs a
crafter-build that has them (Crafter.Build master, fe38cc1 or later).
Also:
- maintenance5 is enabled as a feature, not only as an extension:
every VulkanBuffer already relied on VkBufferUsageFlags2CreateInfo.
- Barrier stage masks drop RAY_TRACING_SHADER on devices without ray
tracing, and ImageVulkan::Create resolves its default consumer stage
to COMPUTE_SHADER there.
- Window refuses a swapchain whose image count is not numFrames
instead of writing past images[]. The limitation itself is #160.
- CRAFTER_GRAPHICS_NO_DESCRIPTOR_HEAP forces the fallback on a driver
that has the heap, so it can be exercised on a desktop GPU.
Verified on an RTX 4090 in both modes under the validation layer, and
on a Fairphone 6 (Turnip, Adreno 810, postmarketOS), where the fallback
is the only path.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Headless benchmark around the native Sponza RT scene: times setup and a
measured Render() loop over the full multi-mesh atrium, prints BENCH
metrics, and exits. Includes run-bench.sh and a README documenting the
methodology and the measured net gain from #40 to current master.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
WebGPUBuffer::EnqueueReadback / PollReadback always copied the full
buffer `size` GPU→staging→wasm. Over-provisioned event-queue buffers
(e.g. Forts3D's GPU physics event drain) paid the full-capacity copy
every drain even when only a small live prefix held data.
Add an optional `byteCount` parameter (default 0 = whole buffer, so the
existing full-buffer callers are unchanged) bounding the readback to the
live prefix. Pass the same byteCount to the paired PollReadback so the
matching number of bytes lands in `.value`.
JS bridge: the staging buffer is now sized to the full device-buffer
capacity (not the first call's byteSize) so a varying prefix length never
overflows it, while the copyBufferToBuffer + mapAsync/getMappedRange are
bounded to the requested prefix — that's where the copy saving lands.
Verified end-to-end in the browser via RayQueryPick: the full readback
still resolves correctly, and a follow-up 8-byte prefix read copies only
hit+customIndex while primitiveIndex keeps its poison sentinel, proving
the copy was bounded. Native `crafter-build test` suite: 24 passed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add a fifth UI compute path — DispatchFused — alongside the four
per-element Dispatch* calls. It composites quads → circles → images →
text (canonical back-to-front order) in ONE dispatch that loads the
destination image once and stores once, eliminating the per-pass
load+store and the inter-pass VkMemoryBarriers a run of consecutive
Dispatch* calls would pay. The win materialises at >= 2 non-empty
categories; an absent category is a zero-trip, push-constant-uniform
loop (~free).
The new uber-kernel (shaders/ui-fused.comp.glsl) reuses each category's
exact cooperative shared-memory tile-cull + per-pixel accumulate, so a
fused category is pixel-identical to its standalone pass. Categories run
sequentially per thread and share one set of shared-memory scratch, so
the VGPR/shared high-water mark stays at the per-category level, not the
sum.
Additive and non-breaking: the per-element Dispatch* calls and the
frozen 48-byte UIDispatchHeader are untouched. DispatchFused gets its own
128-byte push-constant layout (UIFusedHeader: four uvec4 headers + four
per-category clip vec4s). To interleave a custom ui.Dispatch() between
standard passes, bracket it with two DispatchFused calls — the dispatch
boundary is the explicit, app-declared flush point.
WebGPU (Vulkan-second): DispatchFused falls back to the per-element
Dispatch* calls in canonical order — one texture/sampler per dispatch
there can't feed the bindless image phase — so the result matches; only
the load/store fusion is Vulkan-only.
HelloUI now composites its background quads, mouse circle, and label
text in a single DispatchFused. Verified rendering identical on a live
Vulkan/Wayland session.
Resolves#47
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A compute shader (aabbs.comp.{glsl,wgsl}) writes the procedural box into a
device buffer that BuildProcedural consumes by device address/handle with no
host copy; the WebGPU path also refits from it each frame so the box breathes.
Verified rendering on both Vulkan (native) and WebGPU (browser).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Regression test for the procedural BLAS path: the same 3x3x3 grid of
unit-box AABBs runs through a PROCEDURAL_HIT_GROUP_KHR group whose GLSL
intersection shader (reportIntersectionEXT) turns each box into a
radius-1 sphere, the any-hit shader punches the spherical-checkerboard
cut-out (visible proof non-opaque geometry runs any-hit), and the
closest-hit shades per-instance tints — the WebGPU example behavior
reproduced natively. Fixed camera in raygen.glsl; the WebGPU/DOM path is
unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Five pillars, four colored point lights; closest-hit emits one shadow ray
per light from the same invocation (raysPerPixel = 4, maxDepth = 2), so up
to four rays per pixel rtAccumulate in a single SHADE pass — the contention
case #30 exists for. Each pillar casts four separable colored shadows; an
accumulator race or capacity drop shows as flickering dark noise or a
missing shadow color. Two frames a second apart diff at 2 px / 1.85 M
(last-ulp CAS ordering), confirming no lost updates.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
RT→rgba16float→threshold→blur→composite, end-to-end proof of the three
primitives. threshold/blur run from onBeforeUpdate (one submit each) so the
storage-write→sampled-read dependency gets WebGPU's per-submit barrier
(there is none between dispatches within a compute pass); the composite is a
UI custom shader so it owns the canvas ping-pong. Documents the Vulkan
symmetry (gap 4): the native present path records passes generically and
barriers between them, so the same chain is wireable today.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds the minimal WebGPU-backend surface an HDR bloom/post chain needs:
1. wgpuCreateStorageImage2D + StorageImage2D<>: runtime rgba16float (or
other format) textures with STORAGE_BINDING|TEXTURE_BINDING usage, no
CompressedTextureAsset upload — GPU-produced HDR targets.
2. UICustomBindingKind::StorageTexture (kind 5): write-only storage-texture
binding carrying a texel format (the freed UICustomBinding::format byte),
wired through all three binding paths (UI custom / RT / plain compute).
Float textures already sample via SampledTexture (sampleType float).
3. PipelineRTWebGPU::Init(..., hdrOutputFormat): RESOLVE writes the linear
accumulator into a user rgba16float texture (RTPass::outTexHandle)
instead of the rgba8unorm canvas, leaving the composite→swapchain pass to
the app. Default RGBA8Unorm keeps the canvas path byte-identical.
Existing RT examples updated for the _pad→format field rename; the default
paths are unchanged (verified RTStress builds + renders).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds an 8^3 = 512-instance TLAS pick test that shoots one analytically
determined ray through a rayQuery=true PlainComputeShader and checks the
read-back committed hit (customIndex 484, t 40.75). 512 instances sit in
the < 8193 regime that the hardcoded 16384-leaf start used to miss, so the
example fails fast if the shim regresses. Verified in Firefox/WebGPU:
"[RayQueryPick] PASS".
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Indexing a `layout(descriptor_heap)` array with a runtime (non-constant)
index inside a ray-tracing hit shader device-losts on NVIDIA 610.43.02,
for both SSBO and sampled-image descriptors. A constant/spec-constant
index is fine, and the same dynamic pattern works in fragment shaders, so
it's an RT-stage-specific driver fault — the same family as #7/#15
(descriptor-heap AS reads) and #21/#22 (RT recursion + compute TLAS push).
Unlike the AS-read fault, this cannot be worked around transparently: a
sampled image has no device-address escape hatch the way an acceleration
structure does (OpConvertUToAccelerationStructureKHR), and a buffer-only
buffer_reference rewrite would need a whole address-table architecture
while still leaving the texture half broken. So the resolution is the
documented-limitation path (the precedent set by #7).
Records the fault and its isolation in README's Native RT status and in
the Sponza example README (the textured-closest-hit example, which already
reads its albedo through a spec-constant slot for exactly this reason).
Documents the recommended consumer pattern: bind one resource and index
*within* it dynamically (single geometry SSBO / buffer_reference at a
spec-constant slot; one texture2DArray indexed by layer) rather than
selecting a descriptor dynamically — what the WebGPU path already does.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The NVIDIA descriptor-heap AS-read workaround (#15) rewrote heap
acceleration-structure reads into a load of the TLAS device address from
a push-constant block. It always *synthesized a new* push-constant block,
so any ray-tracing shader that already declared one ended up with two —
which SPIR-V forbids ("at most one push constant block statically used per
entry point"), and vkCreateShaderModule's spirv-val check rejected:
Entry point id '4' uses more than one PushConstant interface.
WorkaroundNvidiaAS::Patch now detects an existing PushConstant variable and,
when present, appends a single ulong member (the TLAS address) to that
block instead of adding a second one, reading the address through the
shader's own push-constant variable. The append offset is the end of the
user's block, computed from the members' explicit Offset/ArrayStride/
MatrixStride decorations (correct under both scalar and std140 layout) and
rounded up to 8. Shaders with no push constant of their own keep getting a
freshly synthesized single-member block at offset 0, exactly as before.
That offset is published via Device::workaroundTlasPushOffset and RTPass
feeds it to vkCmdPushDataEXT so the address lands where the rewritten load
reads it (0 for the synthesized case, preserving prior behaviour).
Verified on the affected driver (NVIDIA 610.43.02, RTX 4090): VulkanTriangle
ray-traces correctly and validation-clean both with and without a
user-declared raygen push constant.
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>
A 3x3x3 grid of AABB-geometry spheres rendered through an analytic
ray-sphere intersection shader, with an any-hit spherical-checkerboard
cut-out so the background shows through. Exercises both features end to
end on the WebGPU wavefront tracer.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Investigated the VK_ERROR_DEVICE_LOST on the native VulkanTriangle (#7).
Verified the engine side is correct and validation-clean: the BLAS/TLAS
build finishes before render (FinishInit waits), the built instance is
well-formed (identity transform, mask=0xFF, correct BLAS ref), and
vkWriteResourceDescriptorsEXT stores the TLAS device address at the
expected heap offset (confirmed by dumping the heap bytes). Khronos
validation 1.4.350 reports zero errors.
The fault is isolated to reading the acceleration structure through
VK_EXT_descriptor_heap:
- images/buffers via the same heap render fine (trace disabled -> the
raygen imageStore path renders a full gradient);
- both traceRayEXT and inline rayQueryEXT (no SBT) fault identically on
the AS read;
- reproduces with the AS descriptor at heap byte 0 / shader index 0 (no
offset/stride ambiguity) and regardless of pAddressRange size.
NVIDIA 610.43.02 is the only descriptor_heap implementation available
(llvmpipe lacks the extension), so there is no second implementation to
cross-check. Conclusion: driver-side fault in NVIDIA's brand-new
VK_EXT_descriptor_heap acceleration-structure path; should be reported to
NVIDIA. The traceRayEXT call is left active so the example stays a
faithful reproducer. Documented in both READMEs.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Restructure Sponza for the wavefront model: raygen emits the primary ray;
closesthit (in SHADE) gathers albedo/normal, accumulates ambient, and
emits a shadow ray carrying the pending direct term; miss adds the sky
(primary) or the direct term (shadow miss). resolve.wgsl applies the same
Reinhard+gamma the megakernel raygen did inline. User bindings moved to
group 3 (groups 0..2 reserved). RTPass maxDepth=2.
Renders the atrium correctly through the wavefront pipeline (textures,
two-sided shading, sun+ambient, shadows, tonemap).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Replace the megakernel @compute entry with five wavefront kernels sharing
one module, connected by GPU ray/hit/payload buffers and a GPU-driven
indirect bounce loop:
GENERATE -> (PREP -> TRACE -> SHADE) x maxDepth -> RESOLVE
- TRACE contains zero user code (pure _rtwTraverseTlas/Blas, opaque-only).
- PREP publishes dispatchWorkgroupsIndirect args from the live ray count;
the indirect-args buffer lives in its own bind group so it is never
bound read-write in the same dispatch that consumes it as INDIRECT.
- New emit/accumulate API: rtEmitPrimaryRay / rtEmitRay / rtAccumulate,
plus an optional user Resolve stage (tonemap hook; identity by default).
- Per-pass WfParams via a dynamic-offset uniform ring (curIsA/bounce vary
between passes within one submit).
- Payload-typed wfPayload binding emitted in the codegen region after the
user's struct Payload; payload travels with each ray (2*W*H slots).
- Request maxBufferSize / maxStorageBufferBindingSize / maxComputeWorkgroups
PerDimension so the W*H-sized work buffers fit past the 128MB baseline.
VulkanTriangle ported to the new API and renders bit-identical to the
megakernel baseline at maxDepth=1.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
