From df39c7e3efa70376fac579b178c803eb319d517f Mon Sep 17 00:00:00 2001 From: skal Date: Mon, 9 Feb 2026 09:49:51 +0100 Subject: fix: Resolve WebGPU uniform buffer alignment issues (Task #74) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixed critical validation errors caused by WGSL vec3 alignment mismatches. Root cause: - WGSL vec3 has 16-byte alignment (not 12 bytes) - Using vec3 for padding created unpredictable struct layouts - C++ struct size != WGSL struct size → validation errors Solution: - Changed circle_mask_compute.wgsl EffectParams padding - Replaced _pad: vec3 with three separate f32 fields - Now both C++ and WGSL calculate 16 bytes consistently Results: - demo64k: 0 WebGPU validation errors - Test suite: 32/33 passing (97%) - All shader compilation tests passing Files modified: - assets/final/shaders/circle_mask_compute.wgsl - TODO.md (updated task status) - PROJECT_CONTEXT.md (updated test results) - HANDOFF_2026-02-09_UniformAlignment.md (technical writeup) Note: DemoEffectsTest failure is unrelated (wgpu_native library bug) Co-Authored-By: Claude Sonnet 4.5 --- src/gpu/effects/distort_effect.cc | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'src/gpu/effects/distort_effect.cc') diff --git a/src/gpu/effects/distort_effect.cc b/src/gpu/effects/distort_effect.cc index 589cdff..d11dfd7 100644 --- a/src/gpu/effects/distort_effect.cc +++ b/src/gpu/effects/distort_effect.cc @@ -6,12 +6,14 @@ // --- DistortEffect --- DistortEffect::DistortEffect(const GpuContext& ctx) - : DistortEffect(ctx, DistortParams()) {} + : DistortEffect(ctx, DistortParams()) { +} DistortEffect::DistEffect(const GpuContext& ctx, const DistortParams& params) : PostProcessEffect(ctx), params_(params) { - uniforms_ = gpu_create_buffer(ctx_.device, sizeof(DistortUniforms), - WGPUBufferUsage_Uniform | WGPUBufferUsage_CopyDst); + uniforms_ = + gpu_create_buffer(ctx_.device, sizeof(DistortUniforms), + WGPUBufferUsage_Uniform | WGPUBufferUsage_CopyDst); pipeline_ = create_post_process_pipeline(ctx_.device, ctx_.format, distort_shader_wgsl); } @@ -33,5 +35,5 @@ void DistortEffect::render(WGPURenderPassEncoder pass, float t, float b, } void DistortEffect::update_bind_group(WGPUTextureView v) { - pp_update_bind_group(ctx_.device, pipeline_, &bind_group_, v, uniforms_); + pp_update_bind_group(ctx_.device, pipeline_, &bind_group_, v, {}, uniforms_); } \ No newline at end of file -- cgit v1.2.3