GXProject

• Category: Transformation and Matrix
• Matrix Status: Implemented
• Matrix Notes: Verified modelview+projection+viewport projection math using GXGetProjectionv and GXGetViewportv parameter formats.
• 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/GXProject.html and SDK source in reference/gx/GXTransform.c.
• Runtime checked in src/gx/pc_gx.c:
  • Performs model->eye transform via 3x4 modelview matrix.
  • Branches on pm[0] (GX_PERSPECTIVE vs GX_ORTHOGRAPHIC) with SDK-equivalent clip-space formulas.
  • Computes screen coordinates using viewport scale/offset exactly in GXGetViewportv parameter layout.
  • Uses null guards in PC path for all input/output pointers (fail-soft behavior).
• Result: function-level parity is correct for projection math and parameter conventions; no runtime code changes needed.