Gfx GX Fn GXSetCurrentMtx - wowjinxy/libPorpoise GitHub Wiki

GXSetCurrentMtx

  • Category: Transformation and Matrix
  • Matrix Status: Implemented
  • Matrix Notes: Verified current PN matrix selection with documented GXPosNrmMtx validation.
  • 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/GXSetCurrentMtx.html and SDK source in reference/gx/GXTransform.c.
  • Runtime checked in src/gx/pc_gx.c:
    • Maps GXPosNrmMtx-style id to internal PN matrix slot and updates current matrix selection.
    • Marks modelview state dirty so subsequent draws use the new current PN matrix.
    • Safe no-op for invalid/non-mappable IDs in PC fail-soft behavior.
    • Behavior matches docs note that explicit per-vertex GX_VA_PNMTXIDX (when present) can override this default.
  • Result: function-level parity is correct for current PN matrix selection semantics; no runtime code changes needed.