Gfx GX Fn GXLoadNrmMtxIndx3x3 - wowjinxy/libPorpoise GitHub Wiki

GXLoadNrmMtxIndx3x3

  • Category: Transformation and Matrix
  • Matrix Status: Implemented
  • Matrix Notes: Verified indexed 3x3 load from GX_NRM_MTX_ARRAY; removed non-doc fallback from position-matrix array.
  • 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/GXLoadNrmMtxIndx3x3.html and SDK source in reference/gx/GXTransform.c.
  • Runtime checked in src/gx/pc_gx.c:
    • Sources matrix data from GX_NRM_MTX_ARRAY only (no fallback to position-matrix array).
    • Uses documented default 3x3 stride when array stride is zero (9 * sizeof(f32)).
    • Loads all 9 matrix elements into the destination normal-matrix slot selected by id.
    • Marks modelview state dirty so subsequent draws consume updated normal matrix.
    • Safe no-op when array base is not configured or destination slot mapping is invalid.
  • Result: function-level parity is correct for indexed 3x3 normal-matrix loading semantics; no runtime code changes needed.