From efe01faa8e6597392aacae946e140d84ad8fae4c Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Fri, 16 Sep 2022 10:08:31 -0700
Subject: [PATCH] Replaced Blit4to4CopyAlpha() with optimized SDL_BlitCopy()
Fixes https://github.com/libsdl-org/SDL/issues/6241
---
src/video/SDL_blit_N.c | 30 ++----------------------------
1 file changed, 2 insertions(+), 28 deletions(-)
diff --git a/src/video/SDL_blit_N.c b/src/video/SDL_blit_N.c
index ae9c308829d..3efa917d68f 100644
--- a/src/video/SDL_blit_N.c
+++ b/src/video/SDL_blit_N.c
@@ -26,6 +26,7 @@
#include "SDL_endian.h"
#include "SDL_cpuinfo.h"
#include "SDL_blit.h"
+#include "SDL_blit_copy.h"
/* General optimized routines that write char by char */
@@ -2246,33 +2247,6 @@ Blit4to4MaskAlpha(SDL_BlitInfo * info)
}
}
-/* blits 32 bit RGBA<->RGBA with both surfaces having the same R,G,B,A fields */
-static void
-Blit4to4CopyAlpha(SDL_BlitInfo * info)
-{
- int width = info->dst_w;
- int height = info->dst_h;
- Uint32 *src = (Uint32 *) info->src;
- int srcskip = info->src_skip;
- Uint32 *dst = (Uint32 *) info->dst;
- int dstskip = info->dst_skip;
-
- /* RGBA->RGBA, COPY_ALPHA */
- while (height--) {
- /* *INDENT-OFF* */ /* clang-format off */
- DUFFS_LOOP(
- {
- *dst = *src;
- ++dst;
- ++src;
- },
- width);
- /* *INDENT-ON* */ /* clang-format on */
- src = (Uint32 *) ((Uint8 *) src + srcskip);
- dst = (Uint32 *) ((Uint8 *) dst + dstskip);
- }
-}
-
/* permutation for mapping srcfmt to dstfmt, overloading or not the alpha channel */
static void
get_permutation(SDL_PixelFormat *srcfmt, SDL_PixelFormat *dstfmt,
@@ -3457,7 +3431,7 @@ SDL_CalculateBlitN(SDL_Surface * surface)
if (a_need == COPY_ALPHA) {
if (srcfmt->Amask == dstfmt->Amask) {
/* Fastpath C fallback: 32bit RGBA<->RGBA blit with matching RGBA */
- blitfun = Blit4to4CopyAlpha;
+ blitfun = SDL_BlitCopy;
} else {
blitfun = BlitNtoNCopyAlpha;
}