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>
