GXGetLightDirv

• Category: Lighting
• Matrix Status: Implemented
• Matrix Notes: Verified macro-only API that forwards to GXGetLightDir with vector component pointers.
• Matrix Link: Gfx-GX-API-Matrix

Official SDK (Reference)

• Manual page: reference/man/gfx/gx/Lighting/GXGetLightDirv.html
• Reference header: reference/gx/GXGet.h
• SDK behavior:
  • C spec is a macro, not a function symbol:
    • #define GXGetLightDirv(lo, vec) (GXGetLightDir((lo), (f32*)(vec), (f32*)(vec)+1, (f32*)(vec)+2))
  • Writes light direction into vector-compatible storage (f32[3] or compatible struct).
  • No additional GX state side effects beyond GXGetLightDir.

libPorpoise Implementation

• Public API declaration: include/dolphin/gx/GXGet.h
• Runtime implementation: macro in header; uses GXGetLightDir implementation in src/gx/pc_gx.c.
• Behavior:
  • Macro expansion shape matches SDK.
  • There is no standalone GXGetLightDirv runtime symbol (expected).
  • Runtime behavior inherits SDK-compatible sign convention from GXGetLightDir.

SDK vs Porpoise Diff

• Signature parity:
  • SDK: macro wrapper API.
  • Porpoise: macro wrapper API (same argument mapping).
• Behavioral parity:
  • SDK: forwards to GXGetLightDir with (vec), (vec)+1, (vec)+2.
  • Porpoise: same forwarding behavior.
• Known divergence:
  • None for macro contract/expansion shape.
  • Underlying GXGetLightDir constness differs by header flavor (SDK references often use const GXLightObj*; Porpoise public header uses non-const pointer type).

Validation Checklist

• GX demo coverage checked
• Pikmin usage path checked
• Matrix status updated if needed
• Notes updated with concrete file/function references

Working Notes

• Confirmed official manual explicitly defines GXGetLightDirv as macro text.
• Confirmed reference header macro and Porpoise macro use identical pointer arithmetic.