Gfx GX Fn GXGetScissor - wowjinxy/libPorpoise GitHub Wiki

GXGetScissor

  • Category: Clipping and Culling
  • Matrix Status: Implemented
  • Matrix Notes: Verified scissor getter returns current GX screen-space rectangle values with SDK-style strict pointer semantics (no fail-soft null handling).
  • 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/Culling/GXGetScissor.html and SDK source in reference/gx/GXTransform.c.
  • SDK behavior:
    • Requires all output pointers (left/top/wd/ht) to be valid (ASSERTMSG contract).
    • Returns screen-space scissor origin and dimensions.
  • Runtime parity update in src/gx/pc_gx.c:
    • Removed per-pointer null guards in GXGetScissor.
    • Function now writes all four outputs unconditionally, matching strict SDK pointer contract.