SDL_blit_0.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
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slouken@libsdl.org
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*/
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#include "SDL_config.h"
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#include "SDL_video.h"
#include "SDL_blit.h"
/* Functions to blit from bitmaps to other surfaces */
static void BlitBto1(SDL_BlitInfo *info)
{
int c;
int width, height;
Uint8 *src, *map, *dst;
int srcskip, dstskip;
/* Set up some basic variables */
width = info->d_width;
height = info->d_height;
src = info->s_pixels;
srcskip = info->s_skip;
dst = info->d_pixels;
dstskip = info->d_skip;
map = info->table;
srcskip += width-(width+7)/8;
if ( map ) {
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( 1 ) {
*dst = map[bit];
}
dst++;
byte <<= 1;
}
src += srcskip;
dst += dstskip;
}
} else {
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( 1 ) {
*dst = bit;
}
dst++;
byte <<= 1;
}
src += srcskip;
dst += dstskip;
}
}
}
static void BlitBto2(SDL_BlitInfo *info)
{
int c;
int width, height;
Uint8 *src;
Uint16 *map, *dst;
int srcskip, dstskip;
/* Set up some basic variables */
width = info->d_width;
height = info->d_height;
src = info->s_pixels;
srcskip = info->s_skip;
dst = (Uint16 *)info->d_pixels;
dstskip = info->d_skip/2;
map = (Uint16 *)info->table;
srcskip += width-(width+7)/8;
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( 1 ) {
*dst = map[bit];
}
byte <<= 1;
dst++;
}
src += srcskip;
dst += dstskip;
}
}
static void BlitBto3(SDL_BlitInfo *info)
{
int c, o;
int width, height;
Uint8 *src, *map, *dst;
int srcskip, dstskip;
/* Set up some basic variables */
width = info->d_width;
height = info->d_height;
src = info->s_pixels;
srcskip = info->s_skip;
dst = info->d_pixels;
dstskip = info->d_skip;
map = info->table;
srcskip += width-(width+7)/8;
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( 1 ) {
o = bit * 4;
dst[0] = map[o++];
dst[1] = map[o++];
dst[2] = map[o++];
}
byte <<= 1;
dst += 3;
}
src += srcskip;
dst += dstskip;
}
}
static void BlitBto4(SDL_BlitInfo *info)
{
int width, height;
Uint8 *src;
Uint32 *map, *dst;
int srcskip, dstskip;
int c;
/* Set up some basic variables */
width = info->d_width;
height = info->d_height;
src = info->s_pixels;
srcskip = info->s_skip;
dst = (Uint32 *)info->d_pixels;
dstskip = info->d_skip/4;
map = (Uint32 *)info->table;
srcskip += width-(width+7)/8;
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( 1 ) {
*dst = map[bit];
}
byte <<= 1;
dst++;
}
src += srcskip;
dst += dstskip;
}
}
static void BlitBto1Key(SDL_BlitInfo *info)
{
int width = info->d_width;
int height = info->d_height;
Uint8 *src = info->s_pixels;
Uint8 *dst = info->d_pixels;
int srcskip = info->s_skip;
int dstskip = info->d_skip;
Uint32 ckey = info->src->colorkey;
Uint8 *palmap = info->table;
int c;
/* Set up some basic variables */
srcskip += width-(width+7)/8;
if ( palmap ) {
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( bit != ckey ) {
*dst = palmap[bit];
}
dst++;
byte <<= 1;
}
src += srcskip;
dst += dstskip;
}
} else {
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( bit != ckey ) {
*dst = bit;
}
dst++;
byte <<= 1;
}
src += srcskip;
dst += dstskip;
}
}
}
static void BlitBto2Key(SDL_BlitInfo *info)
{
int width = info->d_width;
int height = info->d_height;
Uint8 *src = info->s_pixels;
Uint16 *dstp = (Uint16 *)info->d_pixels;
int srcskip = info->s_skip;
int dstskip = info->d_skip;
Uint32 ckey = info->src->colorkey;
Uint8 *palmap = info->table;
int c;
/* Set up some basic variables */
srcskip += width-(width+7)/8;
dstskip /= 2;
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( bit != ckey ) {
*dstp=((Uint16 *)palmap)[bit];
}
byte <<= 1;
dstp++;
}
src += srcskip;
dstp += dstskip;
}
}
static void BlitBto3Key(SDL_BlitInfo *info)
{
int width = info->d_width;
int height = info->d_height;
Uint8 *src = info->s_pixels;
Uint8 *dst = info->d_pixels;
int srcskip = info->s_skip;
int dstskip = info->d_skip;
Uint32 ckey = info->src->colorkey;
Uint8 *palmap = info->table;
int c;
/* Set up some basic variables */
srcskip += width-(width+7)/8;
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( bit != ckey ) {
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SDL_memcpy(dst, &palmap[bit*4], 3);
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}
byte <<= 1;
dst += 3;
}
src += srcskip;
dst += dstskip;
}
}
static void BlitBto4Key(SDL_BlitInfo *info)
{
int width = info->d_width;
int height = info->d_height;
Uint8 *src = info->s_pixels;
Uint32 *dstp = (Uint32 *)info->d_pixels;
int srcskip = info->s_skip;
int dstskip = info->d_skip;
Uint32 ckey = info->src->colorkey;
Uint8 *palmap = info->table;
int c;
/* Set up some basic variables */
srcskip += width-(width+7)/8;
dstskip /= 4;
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( bit != ckey ) {
*dstp=((Uint32 *)palmap)[bit];
}
byte <<= 1;
dstp++;
}
src += srcskip;
dstp += dstskip;
}
}
static void BlitBtoNAlpha(SDL_BlitInfo *info)
{
int width = info->d_width;
int height = info->d_height;
Uint8 *src = info->s_pixels;
Uint8 *dst = info->d_pixels;
int srcskip = info->s_skip;
int dstskip = info->d_skip;
const SDL_Color *srcpal = info->src->palette->colors;
SDL_PixelFormat *dstfmt = info->dst;
int dstbpp;
int c;
const int A = info->src->alpha;
/* Set up some basic variables */
dstbpp = dstfmt->BytesPerPixel;
srcskip += width-(width+7)/8;
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( 1 ) {
Uint32 pixel;
unsigned sR, sG, sB;
unsigned dR, dG, dB;
sR = srcpal[bit].r;
sG = srcpal[bit].g;
sB = srcpal[bit].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);
}
byte <<= 1;
dst += dstbpp;
}
src += srcskip;
dst += dstskip;
}
}
static void BlitBtoNAlphaKey(SDL_BlitInfo *info)
{
int width = info->d_width;
int height = info->d_height;
Uint8 *src = info->s_pixels;
Uint8 *dst = info->d_pixels;
int srcskip = info->s_skip;
int dstskip = info->d_skip;
SDL_PixelFormat *srcfmt = info->src;
SDL_PixelFormat *dstfmt = info->dst;
const SDL_Color *srcpal = srcfmt->palette->colors;
int dstbpp;
int c;
const int A = srcfmt->alpha;
Uint32 ckey = srcfmt->colorkey;
/* Set up some basic variables */
dstbpp = dstfmt->BytesPerPixel;
srcskip += width-(width+7)/8;
while ( height-- ) {
Uint8 byte = 0, bit;
for ( c=0; c<width; ++c ) {
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if ( (c&7) == 0 ) {
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byte = *src++;
}
bit = (byte&0x80)>>7;
if ( bit != ckey ) {
int sR, sG, sB;
int dR, dG, dB;
Uint32 pixel;
sR = srcpal[bit].r;
sG = srcpal[bit].g;
sB = srcpal[bit].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);
}
byte <<= 1;
dst += dstbpp;
}
src += srcskip;
dst += dstskip;
}
}
static SDL_loblit bitmap_blit[] = {
NULL, BlitBto1, BlitBto2, BlitBto3, BlitBto4
};
static SDL_loblit colorkey_blit[] = {
NULL, BlitBto1Key, BlitBto2Key, BlitBto3Key, BlitBto4Key
};
SDL_loblit SDL_CalculateBlit0(SDL_Surface *surface, int blit_index)
{
int which;
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if ( surface->format->BitsPerPixel != 1 ) {
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/* We don't support sub 8-bit packed pixel modes */
return NULL;
}
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if ( surface->map->dst->format->BitsPerPixel < 8 ) {
which = 0;
} else {
which = surface->map->dst->format->BytesPerPixel;
}
switch(blit_index) {
case 0: /* copy */
return bitmap_blit[which];
case 1: /* colorkey */
return colorkey_blit[which];
case 2: /* alpha */
return which >= 2 ? BlitBtoNAlpha : NULL;
case 4: /* alpha + colorkey */
return which >= 2 ? BlitBtoNAlphaKey : NULL;
}
return NULL;
}