GXLoadPosMtxImm

• Category: Transformation and Matrix
• Matrix Status: Implemented
• Matrix Notes: Verified 3x4 row-major load into PN matrix slot; tightened to documented GXPosNrmMtx IDs.
• 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/GXLoadPosMtxImm.html and SDK source in reference/gx/GXTransform.c.
• Runtime checked in src/gx/pc_gx.c:
  • Accepts mtx pointer + matrix id, then copies 12 floats (3x4 row-major) into the selected position matrix slot.
  • Marks modelview state dirty so subsequent draws consume updated matrix.
  • Uses slot mapping for GXPosNrmMtx IDs (GX_PNMTX0..GX_PNMTX9 style IDs).
• Note on SDK nuance:
  • SDK source comments indicate custom IDs may be used in hardware register space, but manual/API names accepted IDs via GXPosNrmMtx.
  • Current PC backend intentionally tracks the documented PN matrix set only (10 slots), which matches common game/demo usage.