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/passthrough_effect.cc | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'src/gpu/effects/passthrough_effect.cc') diff --git a/src/gpu/effects/passthrough_effect.cc b/src/gpu/effects/passthrough_effect.cc index d567caf..93cf948 100644 --- a/src/gpu/effects/passthrough_effect.cc +++ b/src/gpu/effects/passthrough_effect.cc @@ -7,17 +7,19 @@ // --- PassthroughEffect --- PassthroughEffect::PassthroughEffect(const GpuContext& ctx) : PostProcessEffect(ctx) { - uniforms_ = - gpu_create_buffer(ctx_.device, sizeof(float) * 6, - WGPUBufferUsage_Uniform | WGPUBufferUsage_CopyDst); + uniforms_.init(ctx_.device); pipeline_ = create_post_process_pipeline(ctx_.device, ctx_.format, passthrough_shader_wgsl); } void PassthroughEffect::update_bind_group(WGPUTextureView input_view) { - struct { - float t, b, i, a, w, h; - } u = {0, 0, 0, 0, (float)width_, (float)height_}; - wgpuQueueWriteBuffer(ctx_.queue, uniforms_.buffer, 0, &u, sizeof(u)); + const CommonPostProcessUniforms u = { + .resolution = {(float)width_, (float)height_}, + .aspect_ratio = 1.0f, + .time = 0.0f, + .beat = 0.0f, + .audio_intensity = 0.0f, + }; + uniforms_.update(ctx_.queue, u); pp_update_bind_group(ctx_.device, pipeline_, &bind_group_, input_view, - uniforms_); + uniforms_.get(), {}); } -- cgit v1.2.3