SDL_image: An example image loading library for use with SDL

Copyright (C) 1999, 2000, 2001 Sam Lantinga

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

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 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

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Sam Lantinga

*/

/* $Id$ */

/* This is a TIFF image file loading framework */

#include <stdio.h>

#include "SDL_image.h"

#ifdef LOAD_TIF

#include <tiffio.h>

/*

* These are the thunking routine to use the SDL_RWops* routines from

* libtiff's internals.

*/

static tsize_t tiff_read(thandle_t fd, tdata_t buf, tsize_t size)

{

return SDL_RWread((SDL_RWops*)fd, buf, 1, size);

}

static toff_t tiff_seek(thandle_t fd, toff_t offset, int origin)

{

return SDL_RWseek((SDL_RWops*)fd, offset, origin);

}

static tsize_t tiff_write(thandle_t fd, tdata_t buf, tsize_t size)

{

return SDL_RWwrite((SDL_RWops*)fd, buf, 1, size);

}

static int tiff_close(thandle_t fd)

{

/*

* We don't want libtiff closing our SDL_RWops*, but if it's not given

* a routine to try, and if the image isn't a TIFF, it'll segfault.

*/

return 0;

}

static toff_t tiff_size(thandle_t fd)

{

Uint32 save_pos;

toff_t size;

save_pos = SDL_RWtell((SDL_RWops*)fd);

SDL_RWseek((SDL_RWops*)fd, 0, SEEK_END);

size = SDL_RWtell((SDL_RWops*)fd);

SDL_RWseek((SDL_RWops*)fd, save_pos, SEEK_SET);

return size;

}

int IMG_isTIF(SDL_RWops* src)

{

TIFF* tiff;

TIFFErrorHandler prev_handler;

/* Suppress output from libtiff */

prev_handler = TIFFSetErrorHandler(NULL);

/* Attempt to process the given file data */

/* turn off memory mapped access with the m flag */

tiff = TIFFClientOpen("SDL_image", "rm", (thandle_t)src,

tiff_read, tiff_write, tiff_seek, tiff_close, tiff_size, NULL, NULL);

/* Reset the default error handler, since it can be useful for info */

TIFFSetErrorHandler(prev_handler);

/* If it's not a TIFF, then tiff will be NULL. */

if(!tiff)

return 0;

/* Free up any dynamically allocated memory libtiff uses */

TIFFClose(tiff);

return 1;

}

SDL_Surface* IMG_LoadTIF_RW(SDL_RWops* src)

{

TIFF* tiff;

SDL_Surface* surface = NULL;

Uint32 img_width, img_height;

Uint32 x, y;

Uint32 half;

/* turn off memory mapped access with the m flag */

tiff = TIFFClientOpen("SDL_image", "rm", (thandle_t)src,

tiff_read, tiff_write, tiff_seek, tiff_close, tiff_size, NULL, NULL);

if(!tiff)

return NULL;

/* Retrieve the dimensions of the image from the TIFF tags */

TIFFGetField(tiff, TIFFTAG_IMAGEWIDTH, &img_width);

TIFFGetField(tiff, TIFFTAG_IMAGELENGTH, &img_height);

Rmask = 0x000000FF;

Gmask = 0x0000FF00;

Bmask = 0x00FF0000;

Amask = 0xFF000000;

surface = SDL_AllocSurface(SDL_SWSURFACE, img_width, img_height, 32,

Rmask, Gmask, Bmask, Amask);

if(!surface)

return NULL;

if(!TIFFReadRGBAImage(tiff, img_width, img_height, surface->pixels, 0))

return NULL;

Uint32 *top = (Uint32 *)surface->pixels + y * surface->pitch/4;

Uint32 *bot = (Uint32 *)surface->pixels

+ (img_height - y - 1) * surface->pitch/4;

for(x = 0; x < img_width; x++)

{

Uint32 tmp = top[x];

top[x] = bot[x];

bot[x] = tmp;

}

}

TIFFClose(tiff);

return surface;

}

#else

/* See if an image is contained in a data source */

int IMG_isTIF(SDL_RWops *src)

{

return(0);

}

/* Load a TIFF type image from an SDL datasource */

SDL_Surface *IMG_LoadTIF_RW(SDL_RWops *src)

{

return(NULL);

}

#endif /* LOAD_TIF */