IMG_tif.c
author Sam Lantinga <slouken@libsdl.org>
Wed, 18 Jul 2007 07:32:56 +0000
changeset 167 338c85983115
parent 154 201cc5c1b373
child 186 5fbbeabf647f
permissions -rw-r--r--
* PNG and TIFF images are correctly identified even if dynamic libraries
to load them aren't available.
* Fixed loading of TIFF images using libtiff 3.6
     1 /*
     2     SDL_image:  An example image loading library for use with SDL
     3     Copyright (C) 1997-2006 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 /* This is a TIFF image file loading framework */
    24 
    25 #include <stdio.h>
    26 
    27 #include "SDL_image.h"
    28 
    29 #ifdef LOAD_TIF
    30 
    31 #include <tiffio.h>
    32 
    33 static struct {
    34 	int loaded;
    35 	void *handle;
    36 	TIFF* (*TIFFClientOpen)(const char*, const char*, thandle_t, TIFFReadWriteProc, TIFFReadWriteProc, TIFFSeekProc, TIFFCloseProc, TIFFSizeProc, TIFFMapFileProc, TIFFUnmapFileProc);
    37 	void (*TIFFClose)(TIFF*);
    38 	int (*TIFFGetField)(TIFF*, ttag_t, ...);
    39 	int (*TIFFReadRGBAImage)(TIFF*, uint32, uint32, uint32*, int);
    40 	TIFFErrorHandler (*TIFFSetErrorHandler)(TIFFErrorHandler);
    41 } lib;
    42 
    43 #ifdef LOAD_TIF_DYNAMIC
    44 int IMG_InitTIF()
    45 {
    46 	if ( lib.loaded == 0 ) {
    47 		lib.handle = SDL_LoadObject(LOAD_TIF_DYNAMIC);
    48 		if ( lib.handle == NULL ) {
    49 			return -1;
    50 		}
    51 		lib.TIFFClientOpen =
    52 			(TIFF* (*)(const char*, const char*, thandle_t, TIFFReadWriteProc, TIFFReadWriteProc, TIFFSeekProc, TIFFCloseProc, TIFFSizeProc, TIFFMapFileProc, TIFFUnmapFileProc))
    53 			SDL_LoadFunction(lib.handle, "TIFFClientOpen");
    54 		if ( lib.TIFFClientOpen == NULL ) {
    55 			SDL_UnloadObject(lib.handle);
    56 			return -1;
    57 		}
    58 		lib.TIFFClose =
    59 			(void (*)(TIFF*))
    60 			SDL_LoadFunction(lib.handle, "TIFFClose");
    61 		if ( lib.TIFFClose == NULL ) {
    62 			SDL_UnloadObject(lib.handle);
    63 			return -1;
    64 		}
    65 		lib.TIFFGetField =
    66 			(int (*)(TIFF*, ttag_t, ...))
    67 			SDL_LoadFunction(lib.handle, "TIFFGetField");
    68 		if ( lib.TIFFGetField == NULL ) {
    69 			SDL_UnloadObject(lib.handle);
    70 			return -1;
    71 		}
    72 		lib.TIFFReadRGBAImage =
    73 			(int (*)(TIFF*, uint32, uint32, uint32*, int))
    74 			SDL_LoadFunction(lib.handle, "TIFFReadRGBAImage");
    75 		if ( lib.TIFFReadRGBAImage == NULL ) {
    76 			SDL_UnloadObject(lib.handle);
    77 			return -1;
    78 		}
    79 		lib.TIFFSetErrorHandler =
    80 			(TIFFErrorHandler (*)(TIFFErrorHandler))
    81 			SDL_LoadFunction(lib.handle, "TIFFSetErrorHandler");
    82 		if ( lib.TIFFSetErrorHandler == NULL ) {
    83 			SDL_UnloadObject(lib.handle);
    84 			return -1;
    85 		}
    86 	}
    87 	++lib.loaded;
    88 
    89 	return 0;
    90 }
    91 void IMG_QuitTIF()
    92 {
    93 	if ( lib.loaded == 0 ) {
    94 		return;
    95 	}
    96 	if ( lib.loaded == 1 ) {
    97 		SDL_UnloadObject(lib.handle);
    98 	}
    99 	--lib.loaded;
   100 }
   101 #else
   102 int IMG_InitTIF()
   103 {
   104 	if ( lib.loaded == 0 ) {
   105 		lib.TIFFClientOpen = TIFFClientOpen;
   106 		lib.TIFFClose = TIFFClose;
   107 		lib.TIFFGetField = TIFFGetField;
   108 		lib.TIFFReadRGBAImage = TIFFReadRGBAImage;
   109 		lib.TIFFSetErrorHandler = TIFFSetErrorHandler;
   110 	}
   111 	++lib.loaded;
   112 
   113 	return 0;
   114 }
   115 void IMG_QuitTIF()
   116 {
   117 	if ( lib.loaded == 0 ) {
   118 		return;
   119 	}
   120 	if ( lib.loaded == 1 ) {
   121 	}
   122 	--lib.loaded;
   123 }
   124 #endif /* LOAD_TIF_DYNAMIC */
   125 
   126 /*
   127  * These are the thunking routine to use the SDL_RWops* routines from
   128  * libtiff's internals.
   129 */
   130 
   131 static tsize_t tiff_read(thandle_t fd, tdata_t buf, tsize_t size)
   132 {
   133 	return SDL_RWread((SDL_RWops*)fd, buf, 1, size);
   134 }
   135 
   136 static toff_t tiff_seek(thandle_t fd, toff_t offset, int origin)
   137 {
   138 	return SDL_RWseek((SDL_RWops*)fd, offset, origin);
   139 }
   140 
   141 static tsize_t tiff_write(thandle_t fd, tdata_t buf, tsize_t size)
   142 {
   143 	return SDL_RWwrite((SDL_RWops*)fd, buf, 1, size);
   144 }
   145 
   146 static int tiff_close(thandle_t fd)
   147 {
   148 	/*
   149 	 * We don't want libtiff closing our SDL_RWops*, but if it's not given
   150          * a routine to try, and if the image isn't a TIFF, it'll segfault.
   151 	 */
   152 	return 0;
   153 }
   154 
   155 static int tiff_map(thandle_t fd, tdata_t* pbase, toff_t* psize)
   156 {
   157 	return (0);
   158 }
   159 
   160 static void tiff_unmap(thandle_t fd, tdata_t base, toff_t size)
   161 {
   162 	return;
   163 }
   164 
   165 static toff_t tiff_size(thandle_t fd)
   166 {
   167 	Uint32 save_pos;
   168 	toff_t size;
   169 
   170 	save_pos = SDL_RWtell((SDL_RWops*)fd);
   171 	SDL_RWseek((SDL_RWops*)fd, 0, SEEK_END);
   172         size = SDL_RWtell((SDL_RWops*)fd);
   173 	SDL_RWseek((SDL_RWops*)fd, save_pos, SEEK_SET);
   174 	return size;
   175 }
   176 
   177 int IMG_isTIF(SDL_RWops* src)
   178 {
   179 	int start;
   180 	int is_TIF;
   181 	Uint8 magic[4];
   182 
   183 	if ( !src )
   184 		return 0;
   185 	start = SDL_RWtell(src);
   186 	is_TIF = 0;
   187 	if ( SDL_RWread(src, magic, 1, sizeof(magic)) == sizeof(magic) ) {
   188 		if ( (magic[0] == 'I' &&
   189                       magic[1] == 'I' &&
   190 		      magic[2] == 0x2a &&
   191                       magic[3] == 0x00) ||
   192 		     (magic[0] == 'M' &&
   193                       magic[1] == 'M' &&
   194 		      magic[2] == 0x00 &&
   195                       magic[3] == 0x2a) ) {
   196 			is_TIF = 1;
   197 		}
   198 	}
   199 	SDL_RWseek(src, start, SEEK_SET);
   200 	return(is_TIF);
   201 }
   202 
   203 SDL_Surface* IMG_LoadTIF_RW(SDL_RWops* src)
   204 {
   205 	int start;
   206 	TIFF* tiff;
   207 	SDL_Surface* surface = NULL;
   208 	Uint32 img_width, img_height;
   209 	Uint32 Rmask, Gmask, Bmask, Amask;
   210 	Uint32 x, y;
   211 	Uint32 half;
   212 
   213 	if ( !src ) {
   214 		/* The error message has been set in SDL_RWFromFile */
   215 		return NULL;
   216 	}
   217 	start = SDL_RWtell(src);
   218 
   219 	if ( IMG_InitTIF() < 0 ) {
   220 		return NULL;
   221 	}
   222 
   223 	/* turn off memory mapped access with the m flag */
   224 	tiff = lib.TIFFClientOpen("SDL_image", "rm", (thandle_t)src, 
   225 		tiff_read, tiff_write, tiff_seek, tiff_close, tiff_size, tiff_map, tiff_unmap);
   226 	if(!tiff)
   227 		goto error;
   228 
   229 	/* Retrieve the dimensions of the image from the TIFF tags */
   230 	lib.TIFFGetField(tiff, TIFFTAG_IMAGEWIDTH, &img_width);
   231 	lib.TIFFGetField(tiff, TIFFTAG_IMAGELENGTH, &img_height);
   232 
   233 	Rmask = 0x000000FF;
   234 	Gmask = 0x0000FF00;
   235 	Bmask = 0x00FF0000;
   236 	Amask = 0xFF000000;
   237 	surface = SDL_AllocSurface(SDL_SWSURFACE, img_width, img_height, 32,
   238 		Rmask, Gmask, Bmask, Amask);
   239 	if(!surface)
   240 		goto error;
   241 	
   242 	if(!lib.TIFFReadRGBAImage(tiff, img_width, img_height, surface->pixels, 0))
   243 		goto error;
   244 
   245 	/* libtiff loads the image upside-down, flip it back */
   246 	half = img_height / 2;
   247 	for(y = 0; y < half; y++)
   248 	{
   249 	        Uint32 *top = (Uint32 *)surface->pixels + y * surface->pitch/4;
   250 	        Uint32 *bot = (Uint32 *)surface->pixels
   251 		              + (img_height - y - 1) * surface->pitch/4;
   252 		for(x = 0; x < img_width; x++)
   253 		{
   254 		        Uint32 tmp = top[x];
   255 			top[x] = bot[x];
   256 			bot[x] = tmp;
   257 		}
   258 	}
   259 	lib.TIFFClose(tiff);
   260 	IMG_QuitTIF();
   261 	
   262 	return surface;
   263 
   264 error:
   265 	SDL_RWseek(src, start, SEEK_SET);
   266 	if ( surface ) {
   267 		SDL_FreeSurface(surface);
   268 	}
   269 	IMG_QuitTIF();
   270 	return NULL;
   271 }
   272 
   273 #else
   274 
   275 /* See if an image is contained in a data source */
   276 int IMG_isTIF(SDL_RWops *src)
   277 {
   278 	return(0);
   279 }
   280 
   281 /* Load a TIFF type image from an SDL datasource */
   282 SDL_Surface *IMG_LoadTIF_RW(SDL_RWops *src)
   283 {
   284 	return(NULL);
   285 }
   286 
   287 #endif /* LOAD_TIF */