- Inline calcColor: eliminates function call, allows OoO overlap of
cache misses on colorCtx with vertex math. Pow path falls back to
game function.
- Inline mat*vec3 transform: V4 FMA chain replaces call to 0x7BCA80.
- VBState: cache VB pointers/strides in locals, write back once after
4 vertices. Eliminates ~80 pointer re-reads per particle.
- @mulAdd throughout vertex loops for FMA codegen.
- A/B verified: BASELINE ~470ms → CUSTOM ~382ms (~20% reduction).
Full recreation of RenderParticleSprites (0x7B2A50, 2688 bytes) in
particle_sse.zig. All 5 code paths: 2D billboard, 3D billboard,
2D+rotation (sin/cos), 3D+rotation (axis-angle matrix), tail particles.
Key fixes during verification:
- colorCtx address: removed Ghidra's spurious -0x12 offset
- calcColor arg2: pass raw u32 from emitter+0x1A8, not truncated
- Texture coord lookups: +8 offset to match assembly's eax increment
between position and texcoord reads in the vertex loop
Verified in-game: particles render identically in CUSTOM vs BASELINE.
Next: optimize with SSE (inline calcColor, V4 vertex math).
- Ghidra C decompilation of RenderParticleSprites (422 lines) and 5
helper functions (calculateColorValues, matVec3Transform, etc.)
- particle_sse.zig with calcColorValues_SSE (10.7x bench but cache-miss
bound in-game — needs inlining into full function replacement)
- Bench harness for calcColorValues with correctness check
- build.zig: particle_sse as separate ReleaseFast compilation unit
- colorDetour reverted to pass-through (SSE has no in-game effect due
to L1 cache misses on scattered ColorCtx structs)
MarcelineVQ