/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2006 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

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

Lesser General Public License for more details.

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

Sam Lantinga

slouken@libsdl.org

*/

#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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

byte = *src++;

}

bit = (byte&0x80)>>7;

if ( bit != ckey ) {

SDL_memcpy(dst, &palmap[bit*4], 3);

}

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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 ) {

if ( (c&7) == 0 ) {

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;

if ( surface->format->BitsPerPixel != 1 ) {

/* We don't support sub 8-bit packed pixel modes */

return NULL;

}

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;

}