wfAccum becomes array<atomic<u32>> (4 slots/pixel, f32 bit patterns — same
16 B/pixel footprint) and rtAccumulate CASes each channel, so N rays for one
pixel may resolve in the same SHADE pass without the read-modify-write
racing. GENERATE clears with atomicStore (bitcast(0.0) == 0u); RESOLVE
atomicLoads + bitcasts the vec4 it hands runResolve.
Capacity half: RTPass::raysPerPixel (default 1) scales the wavefront
ray/hit/payload buffers to raysPerPixel·W·H rays per bounce so the
per-light emits actually fit instead of being dropped by rtEmitRay's
capacity guard. The accumulator stays per-pixel.
No flag-gating: uncontended the CAS succeeds first try — RTStress SHADE
stays at its documented ~1.0 ms and master-vs-branch renders are
byte-identical, so single-ray consumers pay nothing.
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>
Extends the cross-backend RT type surface for procedural geometry +
any-hit on the WebGPU path:
- RTShaderGroupType::ProceduralHitGroup + RTShaderGroup::intersectionShader
(mirror VK_RAY_TRACING_SHADER_GROUP_TYPE_PROCEDURAL_HIT_GROUP_KHR).
- WebGPURTStage::Intersection for AABB intersection shaders.
- Mesh::BuildProcedural(span<RTAabb>, opaque) — the WebGPU analog of a
VK_GEOMETRY_TYPE_AABBS_KHR geometry.
- wgpuRegisterMeshBLAS gains geomType / opaqueFlag / primCount.
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>
