This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
SDL_blit_1.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2011 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"
#include "SDL_sysvideo.h"
#include "SDL_endian.h"
/* Functions to blit from 8-bit surfaces to other surfaces */
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static void
Blit1to1(SDL_BlitInfo * info)
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{
#ifndef USE_DUFFS_LOOP
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#endif
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int width, height;
Uint8 *src, *map, *dst;
int srcskip, dstskip;
/* Set up some basic variables */
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width = info->dst_w;
height = info->dst_h;
src = info->src;
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srcskip = info->src_skip;
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dst = info->dst;
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dstskip = info->dst_skip;
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map = info->table;
while (height--) {
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#ifdef USE_DUFFS_LOOP
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/* *INDENT-OFF* */
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DUFFS_LOOP(
{
*dst = map[*src];
}
dst++;
src++;
, width);
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/* *INDENT-ON* */
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#else
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for (c = width; c; --c) {
*dst = map[*src];
dst++;
src++;
}
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#endif
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src += srcskip;
dst += dstskip;
}
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/* This is now endian dependent */
#if ( SDL_BYTEORDER == SDL_LIL_ENDIAN )
#define HI 1
#define LO 0
#else /* ( SDL_BYTEORDER == SDL_BIG_ENDIAN ) */
#define HI 0
#define LO 1
#endif
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static void
Blit1to2(SDL_BlitInfo * info)
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{
#ifndef USE_DUFFS_LOOP
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#endif
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int width, height;
Uint8 *src, *dst;
Uint16 *map;
int srcskip, dstskip;
/* Set up some basic variables */
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width = info->dst_w;
height = info->dst_h;
src = info->src;
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srcskip = info->src_skip;
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dst = info->dst;
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dstskip = info->dst_skip;
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map = (Uint16 *) info->table;
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#ifdef USE_DUFFS_LOOP
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while (height--) {
/* *INDENT-OFF* */
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DUFFS_LOOP(
{
*(Uint16 *)dst = map[*src++];
dst += 2;
},
width);
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/* *INDENT-ON* */
src += srcskip;
dst += dstskip;
}
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#else
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/* Memory align at 4-byte boundary, if necessary */
if ((long) dst & 0x03) {
/* Don't do anything if width is 0 */
if (width == 0) {
return;
}
--width;
while (height--) {
/* Perform copy alignment */
*(Uint16 *) dst = map[*src++];
dst += 2;
/* Copy in 4 pixel chunks */
for (c = width / 4; c; --c) {
*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
src += 2;
dst += 4;
*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
src += 2;
dst += 4;
}
/* Get any leftovers */
switch (width & 3) {
case 3:
*(Uint16 *) dst = map[*src++];
dst += 2;
case 2:
*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
src += 2;
dst += 4;
break;
case 1:
*(Uint16 *) dst = map[*src++];
dst += 2;
break;
}
src += srcskip;
dst += dstskip;
}
} else {
while (height--) {
/* Copy in 4 pixel chunks */
for (c = width / 4; c; --c) {
*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
src += 2;
dst += 4;
*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
src += 2;
dst += 4;
}
/* Get any leftovers */
switch (width & 3) {
case 3:
*(Uint16 *) dst = map[*src++];
dst += 2;
case 2:
*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
src += 2;
dst += 4;
break;
case 1:
*(Uint16 *) dst = map[*src++];
dst += 2;
break;
}
src += srcskip;
dst += dstskip;
}
}
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#endif /* USE_DUFFS_LOOP */
}
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static void
Blit1to3(SDL_BlitInfo * info)
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{
#ifndef USE_DUFFS_LOOP
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#endif
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int o;
int width, height;
Uint8 *src, *map, *dst;
int srcskip, dstskip;
/* Set up some basic variables */
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width = info->dst_w;
height = info->dst_h;
src = info->src;
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srcskip = info->src_skip;
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dst = info->dst;
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dstskip = info->dst_skip;
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map = info->table;
while (height--) {
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#ifdef USE_DUFFS_LOOP
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/* *INDENT-OFF* */
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DUFFS_LOOP(
{
o = *src * 4;
dst[0] = map[o++];
dst[1] = map[o++];
dst[2] = map[o++];
}
src++;
dst += 3;
, width);
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/* *INDENT-ON* */
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#else
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for (c = width; c; --c) {
o = *src * 4;
dst[0] = map[o++];
dst[1] = map[o++];
dst[2] = map[o++];
src++;
dst += 3;
}
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#endif /* USE_DUFFS_LOOP */
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src += srcskip;
dst += dstskip;
}
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}
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static void
Blit1to4(SDL_BlitInfo * info)
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{
#ifndef USE_DUFFS_LOOP
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#endif
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int width, height;
Uint8 *src;
Uint32 *map, *dst;
int srcskip, dstskip;
/* Set up some basic variables */
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width = info->dst_w;
height = info->dst_h;
src = info->src;
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srcskip = info->src_skip;
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dst = (Uint32 *) info->dst;
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dstskip = info->dst_skip / 4;
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map = (Uint32 *) info->table;
while (height--) {
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#ifdef USE_DUFFS_LOOP
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/* *INDENT-OFF* */
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DUFFS_LOOP(
*dst++ = map[*src++];
, width);
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/* *INDENT-ON* */
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#else
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for (c = width / 4; c; --c) {
*dst++ = map[*src++];
*dst++ = map[*src++];
*dst++ = map[*src++];
*dst++ = map[*src++];
}
switch (width & 3) {
case 3:
*dst++ = map[*src++];
case 2:
*dst++ = map[*src++];
case 1:
*dst++ = map[*src++];
}
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#endif /* USE_DUFFS_LOOP */
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src += srcskip;
dst += dstskip;
}
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}
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static void
Blit1to1Key(SDL_BlitInfo * info)
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{
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int width = info->dst_w;
int height = info->dst_h;
Uint8 *src = info->src;
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int srcskip = info->src_skip;
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Uint8 *dst = info->dst;
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int dstskip = info->dst_skip;
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Uint8 *palmap = info->table;
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Uint32 ckey = info->colorkey;
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if (palmap) {
while (height--) {
/* *INDENT-OFF* */
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DUFFS_LOOP(
{
if ( *src != ckey ) {
*dst = palmap[*src];
}
dst++;
src++;
},
width);
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/* *INDENT-ON* */
src += srcskip;
dst += dstskip;
}
} else {
while (height--) {
/* *INDENT-OFF* */
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DUFFS_LOOP(
{
if ( *src != ckey ) {
*dst = *src;
}
dst++;
src++;
},
width);
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/* *INDENT-ON* */
src += srcskip;
dst += dstskip;
}
}
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}
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static void
Blit1to2Key(SDL_BlitInfo * info)
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{
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int width = info->dst_w;
int height = info->dst_h;
Uint8 *src = info->src;
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int srcskip = info->src_skip;
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Uint16 *dstp = (Uint16 *) info->dst;
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int dstskip = info->dst_skip;
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Uint16 *palmap = (Uint16 *) info->table;
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Uint32 ckey = info->colorkey;
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/* Set up some basic variables */
dstskip /= 2;
while (height--) {
/* *INDENT-OFF* */
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DUFFS_LOOP(
{
if ( *src != ckey ) {
*dstp=palmap[*src];
}
src++;
dstp++;
},
width);
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/* *INDENT-ON* */
src += srcskip;
dstp += dstskip;
}
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}
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static void
Blit1to3Key(SDL_BlitInfo * info)
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{
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int width = info->dst_w;
int height = info->dst_h;
Uint8 *src = info->src;
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int srcskip = info->src_skip;
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Uint8 *dst = info->dst;
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int dstskip = info->dst_skip;
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Uint8 *palmap = info->table;
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Uint32 ckey = info->colorkey;
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int o;
while (height--) {
/* *INDENT-OFF* */
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DUFFS_LOOP(
{
if ( *src != ckey ) {
o = *src * 4;
dst[0] = palmap[o++];
dst[1] = palmap[o++];
dst[2] = palmap[o++];
}
src++;
dst += 3;
},
width);
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/* *INDENT-ON* */
src += srcskip;
dst += dstskip;
}
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}
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static void
Blit1to4Key(SDL_BlitInfo * info)
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{
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int width = info->dst_w;
int height = info->dst_h;
Uint8 *src = info->src;
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int srcskip = info->src_skip;
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Uint32 *dstp = (Uint32 *) info->dst;
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int dstskip = info->dst_skip;
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Uint32 *palmap = (Uint32 *) info->table;
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Uint32 ckey = info->colorkey;
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/* Set up some basic variables */
dstskip /= 4;
while (height--) {
/* *INDENT-OFF* */
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DUFFS_LOOP(
{
if ( *src != ckey ) {
*dstp = palmap[*src];
}
src++;
dstp++;
},
width);
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/* *INDENT-ON* */
src += srcskip;
dstp += dstskip;
}
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}
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static void
Blit1toNAlpha(SDL_BlitInfo * info)
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{
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int width = info->dst_w;
int height = info->dst_h;
Uint8 *src = info->src;
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int srcskip = info->src_skip;
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Uint8 *dst = info->dst;
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int dstskip = info->dst_skip;
SDL_PixelFormat *dstfmt = info->dst_fmt;
const SDL_Color *srcpal = info->src_fmt->palette->colors;
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const int A = info->a;
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/* Set up some basic variables */
dstbpp = dstfmt->BytesPerPixel;
while (height--) {
int sR, sG, sB;
int dR, dG, dB;
/* *INDENT-OFF* */
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DUFFS_LOOP4(
{
Uint32 pixel;
sR = srcpal[*src].r;
sG = srcpal[*src].g;
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;
},
width);
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/* *INDENT-ON* */
src += srcskip;
dst += dstskip;
}
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}
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static void
Blit1toNAlphaKey(SDL_BlitInfo * info)
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{
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int width = info->dst_w;
int height = info->dst_h;
Uint8 *src = info->src;
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int srcskip = info->src_skip;
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Uint8 *dst = info->dst;
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int dstskip = info->dst_skip;
SDL_PixelFormat *srcfmt = info->src_fmt;
SDL_PixelFormat *dstfmt = info->dst_fmt;
const SDL_Color *srcpal = info->src_fmt->palette->colors;
Uint32 ckey = info->colorkey;
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const int A = info->a;
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/* Set up some basic variables */
dstbpp = dstfmt->BytesPerPixel;
while (height--) {
int sR, sG, sB;
int dR, dG, dB;
/* *INDENT-OFF* */
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DUFFS_LOOP(
{
if ( *src != ckey ) {
Uint32 pixel;
sR = srcpal[*src].r;
sG = srcpal[*src].g;
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;
},
width);
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/* *INDENT-ON* */
src += srcskip;
dst += dstskip;
}
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}
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static const SDL_BlitFunc one_blit[] = {
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NULL, Blit1to1, Blit1to2, Blit1to3, Blit1to4
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};
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static const SDL_BlitFunc one_blitkey[] = {
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NULL, Blit1to1Key, Blit1to2Key, Blit1to3Key, Blit1to4Key
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};
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SDL_BlitFunc
SDL_CalculateBlit1(SDL_Surface * surface)
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{
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int which;
SDL_PixelFormat *dstfmt;
dstfmt = surface->map->dst->format;
if (dstfmt->BitsPerPixel < 8) {
which = 0;
} else {
which = dstfmt->BytesPerPixel;
}
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switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {
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return one_blit[which];
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case SDL_COPY_COLORKEY:
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return one_blitkey[which];
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case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
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/* Supporting 8bpp->8bpp alpha is doable but requires lots of
tables which consume space and takes time to precompute,
so is better left to the user */
return which >= 2 ? Blit1toNAlpha : NULL;
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case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
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return which >= 2 ? Blit1toNAlphaKey : NULL;
}
return NULL;
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}
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/* vi: set ts=4 sw=4 expandtab: */