From 6bcf70dc6da17321690651e968d070be7b17f2f6 Mon Sep 17 00:00:00 2001 From: rogerman Date: Sat, 19 Jul 2025 18:53:07 -0700 Subject: [PATCH] Colorspace Handler: Fix RGBA8888 to RGBA5551 color conversions in AltiVec. --- .../colorspacehandler_AltiVec.cpp | 25 +++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/desmume/src/utils/colorspacehandler/colorspacehandler_AltiVec.cpp b/desmume/src/utils/colorspacehandler/colorspacehandler_AltiVec.cpp index 752154b6d..9c20dbd5e 100644 --- a/desmume/src/utils/colorspacehandler/colorspacehandler_AltiVec.cpp +++ b/desmume/src/utils/colorspacehandler/colorspacehandler_AltiVec.cpp @@ -207,7 +207,19 @@ FORCEINLINE v128u16 _ConvertColorBaseTo5551_AltiVec(const v128u32 &srcLo, const // Convert alpha dstAlpha = vec_packsu( vec_and(srcLo, ((v128u32){0x000000FF,0x000000FF,0x000000FF,0x000000FF})), vec_and(srcHi, ((v128u32){0x000000FF,0x000000FF,0x000000FF,0x000000FF})) ); dstAlpha = vec_cmpgt( dstAlpha, vec_splat_u16(0) ); - dstAlpha = vec_and( dstAlpha, ((v128u16){0x8000,0x8000,0x8000,0x8000,0x8000,0x8000,0x8000,0x8000}) ); + + if (COLORFORMAT == NDSColorFormat_BGR666_Rev) + { + dstAlpha = vec_and( dstAlpha, ((v128u16){0x8000,0x8000,0x8000,0x8000,0x8000,0x8000,0x8000,0x8000}) ); + } + else if (COLORFORMAT == NDSColorFormat_BGR888_Rev) + { + // TODO: Don't know why RGBA8888 colors need to swap bytes for the final 16-bit color + // when RGBA6665 colors don't need to, but real-world testing shows that RGBA8888 colors + // need to do this. Further testing is needed to find out why this byte swap is necessary. + // - rogerman, 2025/07/19 + dstAlpha = vec_and( dstAlpha, ((v128u16){0x0080,0x0080,0x0080,0x0080,0x0080,0x0080,0x0080,0x0080}) ); + } // Convert RGB if (SWAP_RB) @@ -221,8 +233,17 @@ FORCEINLINE v128u16 _ConvertColorBaseTo5551_AltiVec(const v128u32 &srcLo, const rgbHi = vec_perm( (v128u8)rgbHi, (v128u8)rgbHi, ((v128u8){3,2,1,0, 7,6,5,4, 11,10,9,8, 15,14,13,12}) ); } + // Convert from 32-bit color to 16-bit color using the built-in AltiVec instruction vpkpx. dstColor = (v128u16)vec_packpx(rgbLo, rgbHi); - dstColor = vec_and( dstColor, ((v128u16){0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF}) ); + + if (COLORFORMAT == NDSColorFormat_BGR666_Rev) + { + dstColor = vec_and( dstColor, ((v128u16){0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF}) ); + } + else if (COLORFORMAT == NDSColorFormat_BGR888_Rev) + { + dstColor = vec_and( dstColor, ((v128u16){0xFF7F,0xFF7F,0xFF7F,0xFF7F,0xFF7F,0xFF7F,0xFF7F,0xFF7F}) ); + } return (v128u16)vec_or( (v128u8)dstColor, (v128u8)dstAlpha ); }