Commit d5ba5bb05f60f922306265539ae264a9bad6c9a3
2023-10-04T21:17:13
blit_slow: don't read destination pixel when you're going to discard it anyways (cherry picked from commit 4cd0c13823551cce279c9ff3d284c41c28deb3d8) (cherry picked from commit 2d5c05a69cca65e0eb01b4bae23737fe970f7bb1)
diff --git a/src/video/SDL_blit_slow.c b/src/video/SDL_blit_slow.c
index 9ea5c38..fb8516b 100644
--- a/src/video/SDL_blit_slow.c
+++ b/src/video/SDL_blit_slow.c
@@ -106,15 +106,20 @@ void SDL_Blit_Slow(SDL_BlitInfo *info)
continue;
}
}
- if (FORMAT_HAS_ALPHA(dstfmt_val)) {
- DISEMBLE_RGBA(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG, dstB, dstA);
- } else if (FORMAT_HAS_NO_ALPHA(dstfmt_val)) {
- DISEMBLE_RGB(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG, dstB);
- dstA = 0xFF;
+ if ((flags & (SDL_COPY_BLEND | SDL_COPY_ADD | SDL_COPY_MOD | SDL_COPY_MUL))) {
+ if (FORMAT_HAS_ALPHA(dstfmt_val)) {
+ DISEMBLE_RGBA(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG, dstB, dstA);
+ } else if (FORMAT_HAS_NO_ALPHA(dstfmt_val)) {
+ DISEMBLE_RGB(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG, dstB);
+ dstA = 0xFF;
+ } else {
+ /* SDL_PIXELFORMAT_ARGB2101010 */
+ dstpixel = *((Uint32 *) (dst));
+ RGBA_FROM_ARGB2101010(dstpixel, dstR, dstG, dstB, dstA);
+ }
} else {
- /* SDL_PIXELFORMAT_ARGB2101010 */
- dstpixel = *((Uint32 *)(dst));
- RGBA_FROM_ARGB2101010(dstpixel, dstR, dstG, dstB, dstA);
+ /* don't care */
+ dstR = dstG = dstB = dstA = 0;
}
if (flags & SDL_COPY_MODULATE_COLOR) {