/*    SDL_image:  An example image loading library for use with SDL    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*//* * PCX file reader: * Supports: *  1..4 bits/pixel in multiplanar format (1 bit/plane/pixel) *  8 bits/pixel in single-planar format (8 bits/plane/pixel) *  24 bits/pixel in 3-plane format (8 bits/plane/pixel) * * (The <8bpp formats are expanded to 8bpp surfaces) * * Doesn't support: *  single-planar packed-pixel formats other than 8bpp *  4-plane 32bpp format with a fourth "intensity" plane */#include <stdio.h>#include <stdlib.h>#include "SDL_endian.h"#include "SDL_image.h"#ifdef LOAD_PCXstruct PCXheader {	Uint8 Manufacturer;	Uint8 Version;	Uint8 Encoding;	Uint8 BitsPerPixel;	Sint16 Xmin, Ymin, Xmax, Ymax;	Sint16 HDpi, VDpi;	Uint8 Colormap[48];	Uint8 Reserved;	Uint8 NPlanes;	Sint16 BytesPerLine;	Sint16 PaletteInfo;	Sint16 HscreenSize;	Sint16 VscreenSize;	Uint8 Filler[54];};/* See if an image is contained in a data source */int IMG_isPCX(SDL_RWops *src){	int start;	int is_PCX;	const int ZSoft_Manufacturer = 10;	const int PC_Paintbrush_Version = 5;	const int PCX_RunLength_Encoding = 1;	struct PCXheader pcxh;	if ( !src )		return 0;	start = SDL_RWtell(src);	is_PCX = 0;	if ( SDL_RWread(src, &pcxh, sizeof(pcxh), 1) == 1 ) {		if ( (pcxh.Manufacturer == ZSoft_Manufacturer) &&		     (pcxh.Version == PC_Paintbrush_Version) &&		     (pcxh.Encoding == PCX_RunLength_Encoding) ) {			is_PCX = 1;		}	}	SDL_RWseek(src, start, SEEK_SET);	return(is_PCX);}/* Load a PCX type image from an SDL datasource */SDL_Surface *IMG_LoadPCX_RW(SDL_RWops *src){	int start;	struct PCXheader pcxh;	Uint32 Rmask;	Uint32 Gmask;	Uint32 Bmask;	Uint32 Amask;	SDL_Surface *surface = NULL;	int width, height;	int y, bpl;	Uint8 *row, *buf = NULL;	char *error = NULL;	int bits, src_bits;	if ( !src ) {		/* The error message has been set in SDL_RWFromFile */		return NULL;	}	start = SDL_RWtell(src);	if ( ! SDL_RWread(src, &pcxh, sizeof(pcxh), 1) ) {		error = "file truncated";		goto done;	}	pcxh.Xmin = SDL_SwapLE16(pcxh.Xmin);	pcxh.Ymin = SDL_SwapLE16(pcxh.Ymin);	pcxh.Xmax = SDL_SwapLE16(pcxh.Xmax);	pcxh.Ymax = SDL_SwapLE16(pcxh.Ymax);	pcxh.BytesPerLine = SDL_SwapLE16(pcxh.BytesPerLine);	/* Create the surface of the appropriate type */	width = (pcxh.Xmax - pcxh.Xmin) + 1;	height = (pcxh.Ymax - pcxh.Ymin) + 1;	Rmask = Gmask = Bmask = Amask = 0;	src_bits = pcxh.BitsPerPixel * pcxh.NPlanes;	if((pcxh.BitsPerPixel == 1 && pcxh.NPlanes >= 1 && pcxh.NPlanes <= 4)	   || (pcxh.BitsPerPixel == 8 && pcxh.NPlanes == 1)) {		bits = 8;	} else if(pcxh.BitsPerPixel == 8 && pcxh.NPlanes == 3) {		bits = 24;		if ( SDL_BYTEORDER == SDL_LIL_ENDIAN ) {			Rmask = 0x000000FF;			Gmask = 0x0000FF00;			Bmask = 0x00FF0000;		} else {			Rmask = 0xFF0000;			Gmask = 0x00FF00;			Bmask = 0x0000FF;		}	} else {		error = "unsupported PCX format";		goto done;	}	surface = SDL_AllocSurface(SDL_SWSURFACE, width, height,				   bits, Rmask, Gmask, Bmask, Amask);	if ( surface == NULL )		goto done;	bpl = pcxh.NPlanes * pcxh.BytesPerLine;	buf = malloc(bpl);	row = surface->pixels;	for ( y=0; y<surface->h; ++y ) {		/* decode a scan line to a temporary buffer first */		int i, count = 0;		Uint8 ch;		Uint8 *dst = (src_bits == 8) ? row : buf;		for(i = 0; i < bpl; i++) {			if(!count) {				if(!SDL_RWread(src, &ch, 1, 1)) {					error = "file truncated";					goto done;				}				if( (ch & 0xc0) == 0xc0) {					count = ch & 0x3f;					if(!SDL_RWread(src, &ch, 1, 1)) {						error = "file truncated";						goto done;					}				} else					count = 1;			}			dst[i] = ch;			count--;		}		if(src_bits <= 4) {			/* expand planes to 1 byte/pixel */			Uint8 *src = buf;			int plane;			for(plane = 0; plane < pcxh.NPlanes; plane++) {				int i, j, x = 0;				for(i = 0; i < pcxh.BytesPerLine; i++) {					Uint8 byte = *src++;					for(j = 7; j >= 0; j--) {						unsigned bit = (byte >> j) & 1;						/* skip padding bits */						if (i * 8 + j >= width)							continue;						row[x++] |= bit << plane;					}				}			} 		} else if(src_bits == 24) {			/* de-interlace planes */			Uint8 *src = buf;			int plane;			for(plane = 0; plane < pcxh.NPlanes; plane++) {				int x;				dst = row + plane;				for(x = 0; x < width; x++) {					*dst = *src++;					dst += pcxh.NPlanes;				}			}		}		row += surface->pitch;	}	if(bits == 8) {		SDL_Color *colors = surface->format->palette->colors;		int nc = 1 << src_bits;		int i;		surface->format->palette->ncolors = nc;		if(src_bits == 8) {			Uint8 ch;			/* look for a 256-colour palette */			do {				if ( !SDL_RWread(src, &ch, 1, 1)) {					error = "file truncated";					goto done;				}			} while ( ch != 12 );			for(i = 0; i < 256; i++) {				SDL_RWread(src, &colors[i].r, 1, 1);				SDL_RWread(src, &colors[i].g, 1, 1);				SDL_RWread(src, &colors[i].b, 1, 1);			}		} else {			for(i = 0; i < nc; i++) {				colors[i].r = pcxh.Colormap[i * 3];				colors[i].g = pcxh.Colormap[i * 3 + 1];				colors[i].b = pcxh.Colormap[i * 3 + 2];			}		}	}done:	free(buf);	if ( error ) {		SDL_RWseek(src, start, SEEK_SET);		if ( surface ) {			SDL_FreeSurface(surface);			surface = NULL;		}		IMG_SetError(error);	}	return(surface);}#else/* See if an image is contained in a data source */int IMG_isPCX(SDL_RWops *src){	return(0);}/* Load a PCX type image from an SDL datasource */SDL_Surface *IMG_LoadPCX_RW(SDL_RWops *src){	return(NULL);}#endif /* LOAD_PCX */