UIRenderer::Dispatch built a fresh std::vector<uint32_t> with reserve on
every call, paying one malloc+free per dispatch. Custom compute dispatches
run per-frame, so make the vector thread_local and clear() it each call:
capacity grows to the high-water mark once and is reused thereafter,
eliminating the per-frame allocation churn. Behavior is identical.
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>
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>
