Mercurial > sdl-ios-xcode
changeset 1232:0aa0000081d5
Added optimized C 32bit RGB<->RGBA alpha masking blitter from Alex Volkov.
Fixes Bugzilla #11.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Thu, 05 Jan 2006 16:40:51 +0000 |
| parents | cf59e7b91ed4 |
| children | 228c94f0b5dc |
| files | src/video/SDL_blit_N.c |
| diffstat | 1 files changed, 58 insertions(+), 2 deletions(-) [+] |
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--- a/src/video/SDL_blit_N.c Thu Jan 05 16:37:46 2006 +0000 +++ b/src/video/SDL_blit_N.c Thu Jan 05 16:40:51 2006 +0000 @@ -1991,6 +1991,52 @@ } } } + +/* 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 @@ } 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