Verified against the running game (freeze-fixed Canary title screen) that
T8aD colours are correct (no R↔B swap) and that wide textures were garbled
by an unreversed tile layout, not a colour bug.
Reversed the layout: large T8aD are stored as 256×256 raster tiles in
row-major order, each tile raster internally, edge tiles clipped to the
image (payload is exactly w*h*4, no padding). Surfaces ≤256px wide are a
single tile column, identical to plain linear — which is why small UI
textures always decoded correctly.
- t8ad.rs: add detile_256() + apply in parse(). Single tile-row / single
tile-column textures now decode exactly (ptcopyright, ptbtn, ptlogo1 =
clean "PROJECT" logo, previously pure noise). Known residual: ≥2×2-tile
textures (>256 in both dims, e.g. the 8AX background) come out coherent
but with boundary seams — the multi-tile order is a subtle swizzle, TBD.
- sylpheed-cli: new `pak textures <pak> <out>` command — decodes every
T8aD (direct, RATC-nested, LSTA frames) to PNG for A/B against the game.
Env debug knobs for layout RE: XTILE/XDESTRIP/XDETILE_W/XREINTERPRET_PITCH
/XSCORE (TV-ranked tile sweep), plus --verbose size classification.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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