GXSetIndTexCoordScale

• Category: Indirect Texturing
• Matrix Status: Implemented
• Matrix Notes: Parity-checked per-stage indirect S/T scale programming, with begin-safe state update and fail-soft scale clamp.
• Matrix Link: Gfx-GX-API-Matrix

Official SDK (Reference)

• Manual page: reference/man/gfx/gx/Indirect/GXSetIndTexCoordScale.html
• SDK source: reference/gx/GXBump.c (GXSetIndTexCoordScale, around lines 247+)
• Verified SDK behavior:
  • Programs S/T indirect-coordinate scale for stages GX_INDTEXSTAGE0..3.
  • Uses CHECK_IN_BGN guard (state update not allowed inside active begin).
  • Switches on stage and writes to one of two packed scale registers (RAS1_SS0 / RAS1_SS1).

libPorpoise Implementation

• Runtime implementation area: src/gx
• Public API surface: include/dolphin/gx
• Current implementation:
  • src/gx/pc_gx.c: GXSetIndTexCoordScale now flushes pending begin state, validates stage against GX_MAX_INDTEXSTAGE, and writes scale selectors into per-stage runtime state used by the shader upload path.
  • Scale values outside documented enum range are clamped fail-soft to GX_ITS_256.

SDK vs Porpoise Diff

• Signature parity:
  • SDK: void GXSetIndTexCoordScale(GXIndTexStageID ind_stage, GXIndTexScale scale_s, GXIndTexScale scale_t)
  • Porpoise: same
• Behavioral parity:
  • SDK: stage-based indirect scale programming with begin guard.
  • Porpoise: same stage mapping semantics and begin-safe update behavior.
• Known divergence:
  • SDK relies on debug asserts / enum-typed values; Porpoise applies fail-soft scale clamping for out-of-range inputs.

Validation Checklist

• GX demo coverage checked (indirect scaling path)
• Pikmin usage path checked (indirect texcoord sampling scales)
• Matrix status updated if needed
• Notes updated with concrete file/function references

Working Notes

• Build sanity target after update: pikmin_demo (Win32 Debug).