static void Blit1toNAlphaKey(SDL_BlitInfo *info)
{
int width = info->d_width;
int height = info->d_height;
int srcskip = info->s_skip;
int dstskip = info->d_skip;
SDL_PixelFormat *srcfmt = info->src;
SDL_PixelFormat *dstfmt = info->dst;
const SDL_Color *srcpal = info->src->palette->colors;
uint32_t ckey = srcfmt->colorkey;
const int A = srcfmt->alpha;
int dstbpp = dstfmt->BytesPerPixel;
uint8_t *src = info->s_pixels;
uint8_t *dst = info->d_pixels;
while ( height-- )
{
int dR, dG, dB;
int n;
for (n = width; n > 0; --n)
{
if ( *src != ckey )
{
uint32_t pixel;
int sR = srcpal[*src].r;
int sG = srcpal[*src].g;
int sB = srcpal[*src].b;
DISEMBLE_RGB(dst, dstbpp, dstfmt,
&pixel, &dR, &dG, &dB);
ALPHA_BLEND(sR, sG, sB, A, &dR, &dG, &dB);
ASSEMBLE_RGB(dst, dstbpp, dstfmt, dR, dG, dB);
}
src++;
dst += dstbpp;
}
src += srcskip;
dst += dstskip;
}
}
/* N->1 blending with per-surface alpha */
static void
BlitNto1SurfaceAlpha(SDL_BlitInfo * info)
{
int width = info->dst_w;
int height = info->dst_h;
Uint8 *src = info->src;
int srcskip = info->src_skip;
Uint8 *dst = info->dst;
int dstskip = info->dst_skip;
Uint8 *palmap = info->table;
SDL_PixelFormat *srcfmt = info->src_fmt;
SDL_PixelFormat *dstfmt = info->dst_fmt;
int srcbpp = srcfmt->BytesPerPixel;
Uint32 Pixel;
unsigned sR, sG, sB;
unsigned dR, dG, dB;
const unsigned A = info->a;
while (height--) {
/* *INDENT-OFF* */
DUFFS_LOOP4(
{
DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel, sR, sG, sB);
dR = dstfmt->palette->colors[*dst].r;
dG = dstfmt->palette->colors[*dst].g;
dB = dstfmt->palette->colors[*dst].b;
ALPHA_BLEND_RGB(sR, sG, sB, A, dR, dG, dB);
dR &= 0xff;
dG &= 0xff;
dB &= 0xff;
/* Pack RGB into 8bit pixel */
if ( palmap == NULL ) {
*dst =((dR>>5)<<(3+2))|((dG>>5)<<(2))|((dB>>6)<<(0));
} else {
*dst = palmap[((dR>>5)<<(3+2))|((dG>>5)<<(2))|((dB>>6)<<(0))];
}
dst++;
src += srcbpp;
},
/* The ONE TRUE BLITTER
* This puppy has to handle all the unoptimized cases - yes, it's slow.
*/
void
SDL_Blit_Slow(SDL_BlitInfo * info)
{
const int flags = info->flags;
const Uint32 modulateR = info->r;
const Uint32 modulateG = info->g;
const Uint32 modulateB = info->b;
const Uint32 modulateA = info->a;
Uint32 srcpixel;
Uint32 srcR, srcG, srcB, srcA;
Uint32 dstpixel;
Uint32 dstR, dstG, dstB, dstA;
int srcy, srcx;
int posy, posx;
int incy, incx;
SDL_PixelFormat *src_fmt = info->src_fmt;
SDL_PixelFormat *dst_fmt = info->dst_fmt;
int srcbpp = src_fmt->BytesPerPixel;
int dstbpp = dst_fmt->BytesPerPixel;
srcy = 0;
posy = 0;
incy = (info->src_h << 16) / info->dst_h;
incx = (info->src_w << 16) / info->dst_w;
while (info->dst_h--) {
Uint8 *src = 0;
Uint8 *dst = (Uint8 *) info->dst;
int n = info->dst_w;
srcx = -1;
posx = 0x10000L;
while (posy >= 0x10000L) {
++srcy;
posy -= 0x10000L;
}
while (n--) {
if (posx >= 0x10000L) {
while (posx >= 0x10000L) {
++srcx;
posx -= 0x10000L;
}
src =
(info->src + (srcy * info->src_pitch) + (srcx * srcbpp));
}
if (src_fmt->Amask) {
DISEMBLE_RGBA(src, srcbpp, src_fmt, srcpixel, srcR, srcG,
srcB, srcA);
} else {
DISEMBLE_RGB(src, srcbpp, src_fmt, srcpixel, srcR, srcG,
srcB);
srcA = 0xFF;
}
if (flags & SDL_COPY_COLORKEY) {
/* srcpixel isn't set for 24 bpp */
if (srcbpp == 3) {
srcpixel = (srcR << src_fmt->Rshift) |
(srcG << src_fmt->Gshift) | (srcB << src_fmt->Bshift);
}
if (srcpixel == info->colorkey) {
posx += incx;
dst += dstbpp;
continue;
}
}
if (dst_fmt->Amask) {
DISEMBLE_RGBA(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG,
dstB, dstA);
} else {
DISEMBLE_RGB(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG,
dstB);
dstA = 0xFF;
}
if (flags & SDL_COPY_MODULATE_COLOR) {
srcR = (srcR * modulateR) / 255;
srcG = (srcG * modulateG) / 255;
srcB = (srcB * modulateB) / 255;
}
if (flags & SDL_COPY_MODULATE_ALPHA) {
srcA = (srcA * modulateA) / 255;
}
if (flags & (SDL_COPY_BLEND | SDL_COPY_ADD)) {
/* This goes away if we ever use premultiplied alpha */
if (srcA < 255) {
srcR = (srcR * srcA) / 255;
srcG = (srcG * srcA) / 255;
srcB = (srcB * srcA) / 255;
}
}
switch (flags & (SDL_COPY_BLEND | SDL_COPY_ADD | SDL_COPY_MOD)) {
case 0:
dstR = srcR;
dstG = srcG;
dstB = srcB;
dstA = srcA;
break;
case SDL_COPY_BLEND:
dstR = srcR + ((255 - srcA) * dstR) / 255;
dstG = srcG + ((255 - srcA) * dstG) / 255;
dstB = srcB + ((255 - srcA) * dstB) / 255;
break;
case SDL_COPY_ADD:
dstR = srcR + dstR;
if (dstR > 255)
dstR = 255;
dstG = srcG + dstG;
if (dstG > 255)
dstG = 255;
dstB = srcB + dstB;
if (dstB > 255)
dstB = 255;
break;
case SDL_COPY_MOD:
dstR = (srcR * dstR) / 255;
dstG = (srcG * dstG) / 255;
dstB = (srcB * dstB) / 255;
break;
}
if (dst_fmt->Amask) {
ASSEMBLE_RGBA(dst, dstbpp, dst_fmt, dstR, dstG, dstB, dstA);
} else {
ASSEMBLE_RGB(dst, dstbpp, dst_fmt, dstR, dstG, dstB);
}
posx += incx;
dst += dstbpp;
}
posy += incy;
info->dst += info->dst_pitch;
}
}