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Added optimized C 32bit RGB<->RGBA alpha masking blitter from Alex Volkov.

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Fixes Bugzilla #11.
This commit is contained in:
Ryan C. Gordon
2006-01-05 16:40:51 +00:00
parent d9f58b2f88
commit c5326df6e2
1 changed files with 58 additions and 2 deletions
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60
src/video/SDL_blit_N.c
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@@ -1991,6 +1991,52 @@ static void BlitNto1(SDL_BlitInfo *info)
}
}
}
/* blits 32 bit RGB<->RGBA with both surfaces having the same R,G,B fields */
static void Blit4to4MaskAlpha(SDL_BlitInfo *info)
{
int width = info->d_width;
int height = info->d_height;
Uint32 *src = (Uint32 *)info->s_pixels;
int srcskip = info->s_skip;
Uint32 *dst = (Uint32 *)info->d_pixels;
int dstskip = info->d_skip;
SDL_PixelFormat *srcfmt = info->src;
SDL_PixelFormat *dstfmt = info->dst;
if (dstfmt->Amask) {
/* RGB->RGBA, SET_ALPHA */
Uint32 mask = (srcfmt->alpha >> dstfmt->Aloss) << dstfmt->Ashift;
while ( height-- ) {
DUFFS_LOOP(
{
*dst = *src | mask;
++dst;
++src;
},
width);
src = (Uint32*)((Uint8*)src + srcskip);
dst = (Uint32*)((Uint8*)dst + dstskip);
}
} else {
/* RGBA->RGB, NO_ALPHA */
Uint32 mask = srcfmt->Rmask | srcfmt->Gmask | srcfmt->Bmask;
while ( height-- ) {
DUFFS_LOOP(
{
*dst = *src & mask;
++dst;
++src;
},
width);
src = (Uint32*)((Uint8*)src + srcskip);
dst = (Uint32*)((Uint8*)dst + dstskip);
}
}
}
static void BlitNtoN(SDL_BlitInfo *info)
{
int width = info->d_width;
@@ -2414,8 +2460,18 @@ SDL_loblit SDL_CalculateBlitN(SDL_Surface *surface, int blit_index)
}
sdata->aux_data = table[which].aux_data;
blitfun = table[which].blitfunc;
if(a_need == COPY_ALPHA && blitfun == BlitNtoN)
blitfun = BlitNtoNCopyAlpha;
if(blitfun == BlitNtoN) { /* default C fallback catch-all. Slow! */
/* Fastpath C fallback: 32bit RGB<->RGBA blit with matching RGB */
if ( srcfmt->BytesPerPixel == 4 && dstfmt->BytesPerPixel == 4 &&
srcfmt->Rmask == dstfmt->Rmask &&
srcfmt->Gmask == dstfmt->Gmask &&
srcfmt->Bmask == dstfmt->Bmask ) {
blitfun = Blit4to4MaskAlpha;
} else if ( a_need == COPY_ALPHA ) {
blitfun = BlitNtoNCopyAlpha;
}
}
}
#ifdef DEBUG_ASM