Priority 1: Core Graphics Layer

shachi-gfx (Multi-Pass + Texture Management)

What: The 2 CRITICAL KOS gaps, filled. Why: Multi-pass rendering enables lightmaps, shadow passes, bump mapping, screen-space effects. Texture GC prevents VRAM fragmentation in streaming scenarios. Reference: Kamui KMFLOWCONTROL.C, KMYSTARTRENDER.C, KMLOADTEXTURE.C

Multi-pass (~400 lines C):

shachi_pass_begin(SHACHI_PASS_0);  // Configure OPB, list enables for this pass
  // Submit opaque base geometry
shachi_pass_end();
shachi_pass_begin(SHACHI_PASS_1);  // Second pass config
  // Submit lightmap/bump/shadow overlays with depth-GEQUAL + Z-write disabled
shachi_pass_end();
shachi_render();  // Trigger ISP/TSP

• Up to 4 passes (Kamui does 8 — start conservative)
• Per-pass OPB configuration
• Automatic EOL injection between passes
• Depth comparison mode override per pass

Texture lifecycle (~300 lines C):

shachi_tex_t *tex = shachi_tex_load("texture.pvr");  // Upload to VRAM
shachi_tex_bind(tex);                                   // Make active
shachi_tex_unload(tex);                                 // Free VRAM
shachi_tex_gc();                                        // Defragment

• Track all texture allocations with metadata (size, format, last-used frame)
• LRU eviction for streaming scenarios
• Defragmentation via copy + remap (expensive — call between scenes, not frames)
• SmallVQ-aware loading (reduced codebook for small textures)
• Mipmap-twiddled offset (skip 1 DWORD — KOS misses this)

shachi-clip (Near-Z Clipping)

What: Software near-plane clipping for all submitted geometry. Why: DIV-001 (CRITICAL). Every shipped DC game needed this. PVR2 TA has no near-plane clip. Reference: Kamui/Ninja internal clipping (not in available source — implement from spec). Scope: ~200 lines C. Sutherland-Hodgman against Z=NEAR in camera space. Per-triangle: 3 visible→submit, 0 visible→cull, 2/1 visible→clip to quad/triangle with interpolated vertices.