fix(wow-blp): palettized BLP palette is BGRX, not 0xBBGGRR — swap R↔B#59
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The BLP2 palette colour map is stored as BGRX on disk (byte 0 = B, byte 2 = R). As a little-endian u32 this is 0x00RRGGBB. The encoder packed it as 0x00BBGGRR (R in byte 0, B in byte 2) and the decoder extracted channels to match, so round-tripping wow-blp's own output worked — but reading real Blizzard BLPs swapped red and blue. Verified against 3.3.5a client RE analysis: DecompPalFastPath copies 3 bytes from each palette entry as BGR, confirming the BGRX layout. Also corrects the doc comments on BlpRaw1 and BlpRaw3 which described the layout as 0xBBGGRR. Supersedes #52 and #58 (BLP portion). Closes #52, Closes #58
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Problem
The BLP2 palette colour map is stored as BGRX on disk (byte 0 = B, byte 1 = G, byte 2 = R, byte 3 = padding). As a little-endian u32 this is
0x00RRGGBB.The encoder packed it as
0x00BBGGRR(R in byte 0, B in byte 2) and the decoder extracted channels to match. Round-tripping wow-blp's own output worked, but reading real Blizzard BLPs swapped red and blue.Evidence
Verified against 3.3.5a client (build 12340) reverse engineering analysis:
Changes
palette.rs): Pack palette entries as0x00RRGGBB(B in byte 0, R in byte 2) matching the BGRX disk layoutraw1.rs): Extract R from bits 16–23 and B from bits 0–7 of each palette u32BlpRaw1,BlpRaw3): Corrected0xBBGGRR→0x00RRGGBBand clarified alpha is in a separate arraySupersedes