GXLoadPosMtxIndx

• Category: Transformation and Matrix
• Matrix Status: Implemented
• Matrix Notes: Verified indexed 3x4 load from GX_POS_MTX_ARRAY with documented default stride behavior.
• 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/Transform/GXLoadPosMtxIndx.html and SDK source in reference/gx/GXTransform.c.
• Runtime checked in src/gx/pc_gx.c:
  • Reads matrix data from GX_POS_MTX_ARRAY (g_gx.array_base[GX_POS_MTX_ARRAY]) using mtx_indx * stride.
  • Uses documented default 3x4 stride when array stride is zero (12 * sizeof(f32)).
  • Forwards loaded 3x4 matrix to GXLoadPosMtxImm for slot install at id.
  • Safe no-op when matrix array base is not configured.
• Result: function-level parity is correct for indexed position-matrix loading semantics; no runtime code changes needed.