GXGetVtxAttrFmt

• Category: Geometry and Vertex
• Matrix Status: Implemented
• Matrix Notes: Returns VAT (cnt/type/frac) for attribute in selected vertex format.
• Matrix Link: Gfx-GX-API-Matrix

Official SDK (Reference)

• Manual root: reference/rvlsdk/man/en_US/gx
• Primary SDK source area: demos/PikminDemo/src/gx (GC-style Dolphin GX source)
• Notes:
  • Confirm official signature/prototype
  • Confirm documented side effects (register/state updates)
  • Confirm special behavior and edge cases from manual

libPorpoise Implementation

• Runtime implementation area: src/gx
• Public API surface: include/dolphin/gx
• Notes:
  • Confirm API signature matches SDK
  • Confirm state writes match SDK semantics
  • Confirm backend behavior in PC renderer path

SDK vs Porpoise Diff

• Signature parity:
  • SDK:
  • Porpoise:
• Behavioral parity:
  • SDK:
  • Porpoise:

• Known divergence:

Validation Checklist

• GX demo coverage checked
• Pikmin usage path checked
• Matrix status updated if needed
• Notes updated with concrete file/function references

Working Notes

• Docs checked against reference/man/gfx/gx/Geometry/GXGetVtxAttrFmt.html and SDK source in reference/gx/GXAttr.c.
• Runtime parity updates in src/gx/pc_gx.c:
  • NRM/NBT now return implied normal fixed-point fraction based on type (GX_S8 -> 6, GX_S16 -> 14, else 0).
  • Default branch now matches SDK style fallback for non-VAT attrs (cnt=1, type=GX_U8, frac=0).
  • Supported VAT attrs remain GX_VA_POS, GX_VA_NRM/GX_VA_NBT, GX_VA_CLR0/1, GX_VA_TEX0..7.