GXInitLightColor

• Category: Lighting
• Matrix Status: Implemented
• Matrix Notes: Verified color storage/packing in light object.
• Matrix Link: Gfx-GX-API-Matrix

Official SDK (Reference)

• Manual page: reference/man/gfx/gx/Lighting/GXInitLightColor.html
• Reference source: reference/gx/GXLight.c (GXInitLightColor)
• SDK behavior:
  • Signature: void GXInitLightColor(GXLightObj* lt_obj, GXColor color).
  • Writes the light color into the light object only (no hardware register load).
  • Reference implementation stores GXColor bytes as a packed u32 in object color storage.

libPorpoise Implementation

• Public API declaration: include/dolphin/gx/GXLighting.h
• Runtime implementation: src/gx/pc_gx.c (GXInitLightColor)
• Behavior:
  • Packs GXColor {r,g,b,a} into internal 32-bit color storage and writes into light object state.
  • Loaded to active backend light state later via GXLoadLightObjImm/Indx.
  • Getter path (GXGetLightColor) returns the stored bytes back to GXColor.

SDK vs Porpoise Diff

• Signature parity:
  • SDK: typed GXLightObj*.
  • Porpoise: typed in public header; runtime definition uses internal void* ABI-equivalent pointer.
• Behavioral parity:
  • SDK: store RGBA color in light object memory.
  • Porpoise: same RGBA storage semantics.
• Known divergence:
  • Porpoise calls pc_gx_lightobj_sanitize before setting color; SDK reference path directly writes color field.

Validation Checklist

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

Working Notes

• Verified manual semantics in reference/man/gfx/gx/Lighting/GXInitLightColor.html.
• Verified reference storage behavior in reference/gx/GXLight.c (obj->Color = *(u32*)(&color)).