| name | review-webgpu-parity |
| description | Review changes to WebGPU/WebGL dual-backend parity. Use when a PR touches feedback managers, renderer adapters, shader lowering, or any code that affects both WebGPU and WebGL rendering paths. |
Review WebGPU/WebGL Parity
Use this skill when reviewing or authoring changes to src/js/milkdrop/feedback-manager-*, src/js/milkdrop/renderer-adapter*, src/js/milkdrop/backend-behavior.ts, src/js/milkdrop/compiler/gpu-descriptor-plan.ts, or any shader-lowering code.
Why this exists
The most frequent source of fixes in this repo (~22% of fix commits) is parity drift between WebGPU and WebGL — still the #1 category: alpha blending order, feedback color math, wave interpolation, resolution scales, and shader lowering. This skill prevents those regressions at review time.
Pre-merge checklist
1. Both backends must be exercised
2. No hardcoded backend-specific values without comment
3. Blend alpha order verified
4. Reference presets must not shift
5. Shader lowering comments
What to reject in review
- Unconditional
if (isWebGPU) branches that duplicate logic without a shared helper
- New
innerHTML or string-built shader code without a corresponding test fixture
- Changes to
feedback-manager-shared.ts that do not also update feedback-manager-webgpu.ts (or explain why not)
- Missing regression tests for fixed parity bugs
Related skills