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>
Font::GetLineWidth called stbtt_GetCodepointHMetrics for every glyph on
every invocation. InputField_HitTestCursor rescans the whole field once
per character, making caret hit-testing O(n²) in HMetrics lookups.
Memoise advances per Font via Font::AdvanceUnits: ASCII in a flat array,
the rest in a map. Advances are cached in unscaled font *units* and
rescaled per call — Glyph::advance in the FontAtlas is baked at kBaseSize
and is wrong at any other size, so it cannot be reused. The per-glyph
(int) truncation in GetLineWidth is preserved exactly.
Adds the FontAdvanceCache CPU-only regression test covering size
independence of the cached unit advance, the per-glyph-truncated rescale
pipeline, cache-hit determinism, width scaling with size, and the
non-ASCII map path.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
uiResolveScreenPixel ran four float compares against hdr.clipRectPx for
every pixel of every UI dispatch, even though the clip rect is the
full-surface default {0,0,1e9,1e9} in the overwhelmingly common case.
Reserve the high bit of the header flags word (UI_FLAG_CLIP) and have
FillHeader set it only when the clip rect is narrower than the surface
(extracted into the unit-testable UIRenderer::ClipFlags). The shader
gates the compares on the bit; the branch is push-constant-uniform so it
never diverges. When the rect covers the surface the skipped compares
could never reject an in-surface pixel, so output is pixel-identical.
Mirrored on the WebGPU/WGSL path (dom-webgpu.js) for parity. Adds the
UIClipFlag CPU test covering the gate decision.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
InputField_HitTestCursor mapped a click x to a cursor byte offset by
calling Font::GetLineWidth on every prefix value[0..i] for i=1..size.
Each call re-walks from byte 0, so the hit test was O(n^2) glyph-metric
lookups (each an uncached stbtt cmap binary search). It also iterated
raw byte boundaries, so on multibyte UTF-8 input it could return an
offset splitting a codepoint — an invalid position for the byte-based
cursorPos.
Add Font::NearestCursorByte: one left-to-right cumulative-advance pass
(O(n) metrics, scale computed once) over codepoint boundaries, returning
the byte offset of the boundary nearest the target. Cumulative advance is
monotonic, so the scan stops past the closest boundary. The hit test now
delegates to it.
Adds tests/InputFieldHitTest, a pure-CPU regression test (no Vulkan
device/window): a px sweep across ASCII and multibyte strings compared
against an independent brute-force nearest-boundary oracle, plus the
left/right/empty/end-of-text edge cases and a codepoint-boundary invariant.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
GetMemoryType was a bare first-superset match that threw whenever no
memory type satisfied the requested property flags. Callers combining a
mandatory flag with a perf-only one (HOST_VISIBLE | DEVICE_LOCAL for the
descriptor heaps) would then fail allocation on any device without a
host-visible device-local heap (no resizable BAR).
It now takes a `preferred` mask distinct from `required`: a type
satisfying both is chosen first, falling back to a required-only match
when the preference is unavailable, and throwing only when even
`required` cannot be met. VulkanBuffer::Create/Resize gain an optional
trailing `preferredPropertyFlags`, and the descriptor heaps now treat
DEVICE_LOCAL as a preference on top of mandatory HOST_VISIBLE.
This does not touch any flush/barrier behaviour — coherency is not
assumed anywhere here.
Adds tests/MemoryTypeFallback, a pure-CPU test that installs synthetic
memory layouts and exercises selection, preference, fallback, and the
unsatisfiable-required throw.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
ShapeText re-decoded UTF-8, re-looked-up every glyph, and recomputed
layout every frame for static strings (DrawText / EmitCenteredLabel run
inside per-frame onBuild). DrawText and EmitCenteredLabel also did a
second full pass over the glyphs to apply alignment.
Memoize the shaped run, keyed by (Font*, pxSize, color, utf8), as an
origin-relative vector<GlyphItem>. A cache hit skips decode/lookup/layout
and just translates the cached run into the output buffer by
(x + alignShift, baselineY). The alignment shift (Center = -advance/2,
Right = -advance) is folded into ShapeText's single pass, dropping the
second loop in both callers. TextAlign moves to the :UI partition so
ShapeText can take it.
Pure CPU memoization — the glyph buffer is fully rewritten and re-flushed
every frame, so a hit is byte-equivalent. A miss still calls Ensure so new
glyphs rasterise and dirty the atlas; hits don't (atlas entries are never
evicted). InvalidateFont drops a font's runs before it is destroyed (the
cache, like FontAtlas's glyph cache, keys on the Font pointer). A soft cap
bounds memory against pathological per-frame-unique text.
Adds the ShapeTextCache test (15 checks): hit == miss byte-for-byte, hits
don't touch the atlas, translate/alignment/truncation/InvalidateFont.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
FontAtlas::Update re-uploaded the entire 1024x1024 R8 atlas (1 MiB)
whenever a single glyph was rasterized, so warm-up / language-switch /
size-churn cost roughly one full-atlas copy per frame that added a
codepoint.
Accumulate a dirty bounding box (FontAtlas::DirtyRect) in MarkDirty as
glyphs are placed, and copy only that sub-rect. On Vulkan this is a new
ImageVulkan::UpdateRegion: the staging buffer keeps the full atlas row
stride, so bufferRowLength stays the atlas width and bufferOffset points
at the rect origin while imageOffset/imageExtent carve out the rect.
Layout transitions stay whole-image (cheap); only the copy extent
shrinks. WebGPU passes the rect straight to wgpuWriteAtlasRegion, which
already took x/y/w/h.
The freshly-zeroed atlas marks its whole extent dirty in Initialize so
the first Update clears the image once; thereafter every untouched texel
stays the zero it was uploaded as, keeping the image byte-identical to
the staging copy.
Tested: new FontAtlasDirtyRect unit test covers the accumulation /
clamp / lockstep-with-`dirty` math (no GPU needed); HelloUI renders text
correctly on both Vulkan (NVIDIA, validation-clean) and WebGPU.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The renderer was effectively single-buffered despite allocating
triple-buffered infrastructure: Render() ended with an unconditional
vkQueueWaitIdle, and a single (presentComplete, renderComplete)
semaphore pair with zero fences was shared for the Window's lifetime.
Rework the pacing model so up to numFrames frames overlap:
- Per-swapchain-image VkFence, signaled by the submit and waited+reset
before that image's command buffer / descriptor-heap slot is
re-recorded. Keyed by acquired image index (drawCmdBuffers, the heap
slots, and the swapchain images are all image-indexed — see
WriteSwapchainDescriptors). Created signaled so first use passes.
- Per-image render-finished (present) semaphore: the presentation engine
holds it until the image is re-acquired, so per-image is the only safe
key (per-CPU-frame trips VUID-vkQueueSubmit-pSignalSemaphores-00067).
- Per-CPU-frame acquire semaphores (image index unknown until acquire
returns), sized numFrames+1: in-flight depth is bounded by the
per-image fences, so numFrames+1 distinct acquire semaphores guarantee
the reused one has no pending op (VUID-vkAcquireNextImageKHR-01779).
- Drop the steady-state vkQueueWaitIdle; keep it on resize / OUT_OF_DATE
/ teardown.
Add tests/FrameLoopSync: drives the real frame loop against a live
Wayland compositor for 60 frames (>> in-flight slots) and asserts the
CPU frame counter advanced, the swapchain rotated across multiple
images, and the validation layer stayed silent — the load-bearing check,
since the old single-pair design only avoided being an active race
because the wait-idle masked it.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Extend BLASBuildOptions with a device-local AABB buffer filled via a staging
copy + barrier (standing in for a GPU compute producer) fed into the new
device-address BuildProcedural/RefitProcedural. Asserts the build/refit
succeed, the in-place UPDATE keeps the AS handle + blasAddr, the host
aabbBuffer is never allocated (proof of zero-copy), and the validation layer
reports no errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Exercises the real hardware AS-build path: builds and refits triangle
and procedural BLASes with fast-build/fast-trace + allow-update flags
via one-time command buffers, asserting the requested flags land, that
an allowUpdate refit keeps the same AS handle/blasAddr (in-place
UPDATE), that the no-update / topology-change fallback still produces a
valid BLAS, and that the validation layer reports zero errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Window::onMouseScroll now fires on every backend and speaks one unit:
signed whole detents packed in the uint32 payload, +1 = wheel down
(DOM deltaY sign).
- Wayland: implement the previously-stubbed PointerListenerHandleAxis —
vertical axis only, wl_fixed_to_double / 15 (libinput's units-per-
detent), sub-detent remainder accumulated and reset on pointer leave.
- Win32: add the missing WM_MOUSEWHEEL case — -GET_WHEEL_DELTA_WPARAM /
WHEEL_DELTA with a remainder accumulator for free-spinning wheels.
- DOM: dom-env.js normalizes WheelEvent.deltaY per deltaMode (100px /
3 lines / 1 page per detent) with the same remainder scheme, so wasm
delivers the identical unit instead of raw browser-specific deltas.
- Document the contract on Window::onMouseScroll.
- tests/MouseScroll: compositor-free regression test driving the
Wayland axis handler directly.
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>
Adds tests/PushConstantRewrite, a host test that compiles representative
ray-generation shaders with glslang, runs the real WorkaroundNvidiaAS::Patch
over them, and asserts with spirv-val (the same invocation vkCreateShaderModule
uses) that the result is valid and contains exactly one push-constant block —
covering both the merge path (shaders that already declare a push constant,
including mat4/vec3/uint, a lone uint, and an array layout) and the synthesize
path, plus a no-op case (push constant but no AS read). It also checks the
published TLAS push offset for each layout.
The workaround namespace is exported so the test can drive Patch directly; both
go away with the rest of the workaround. project.cpp wires the test as an
executable that recompiles the module and requires glslang + spirv-val.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
