fix(hal/metal/device.go): [*Device.CreateComputePipeline] and [*Device.CreateRenderPipeline] resolves translated entrypoint name by [naga.TranslationInfo]

[k-chimi]

resolve #168

$ CGO_ENABLED=0 go run ./examples/compute-copy/
=== Compute Shader: Scaled Copy ===

1. Creating instance... OK
2. Requesting adapter... OK (Apple M4 Max)
3. Creating device... OK
4. Input: 1024 float32 elements, scale = 2.5
5. Creating buffers... OK
6. Creating compute pipeline... OK
7. Dispatching compute... OK
8. Reading results... OK

Sample results (first 8):
  [0] 1.0 * 2.5 = 2.5
  [1] 2.0 * 2.5 = 5.0
  [2] 3.0 * 2.5 = 7.5
  [3] 4.0 * 2.5 = 10.0
  [4] 5.0 * 2.5 = 12.5
  [5] 6.0 * 2.5 = 15.0
  [6] 7.0 * 2.5 = 17.5
  [7] 8.0 * 2.5 = 20.0

PASS: all 1024 elements match (tolerance=0.0010)

[kolkov]

Great fix! Correctly identified the root cause — naga MSL renames reserved words like main → main_, and the Metal HAL was using the original name. Matches Rust wgpu-hal pattern (device.rs:231).

Two bugs to fix before merge:

1. Vertex entry point looks up in fragmentModule (line ~607)

entrypointName := desc.Vertex.EntryPoint
if translated, ok := fragmentModule.translatedEntrypointNames[entrypointName]; ok {

Should be vertexModule, not fragmentModule. Works now only because vertex+fragment typically share the same ShaderModule, but breaks with separate modules.

2. getWorkgroupSize receives translated name but map uses original names (line ~842)

workgroupSize := getWorkgroupSize(computeModule, entrypointName)

extractWorkgroupSizes stores ep.Name (original) as key. After translation "main" → "main_", lookup misses → falls back to {64,1,1} instead of the actual workgroup size. Should use desc.Compute.EntryPoint (original name) here, not entrypointName.

Minor

• Field name translatedEntrypointNames → entryPointNames (Go convention, matches naga TranslationInfo.EntryPointNames)
• Non-WGSL path: map[string]string{} → nil (nil map lookup returns false, same behavior, simpler)

[k-chimi]

Thanks! I've fix my code! Please check it when you have a moment 🙏

[kolkov]

Both issues fixed. LGTM! 🎉

• vertexModule correctly used for vertex entry point lookup
• entrypointNames field name is cleaner
• getWorkgroupSize correctly uses original name

Great contribution — solid root cause analysis and clean fix.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!