0,0 → 1,174 |
/* |
IMGLIB: An example image loading library for use with SDL |
Copyright (C) 1999 Sam Lantinga |
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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. |
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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 |
Library General Public License for more details. |
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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 |
5635-34 Springhouse Dr. |
Pleasanton, CA 94588 (USA) |
slouken@devolution.com |
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5/29/2000: TIFF loader written. Mark Baker (mbaker@0x7a69.net) |
2000-07-28: Fixed two off-by one bugs in reversal loop and made it work on |
big-endian machines (Mattias) |
2000-08-09: Removed alpha inversion (Mattias) |
*/ |
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/* This is a TIFF image file loading framework */ |
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#include <stdio.h> |
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#include "SDL_image.h" |
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#ifdef LOAD_TIF |
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#include <tiffio.h> |
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/* |
* These are the thunking routine to use the SDL_RWops* routines from |
* libtiff's internals. |
*/ |
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static tsize_t tiff_read(thandle_t fd, tdata_t buf, tsize_t size) |
{ |
return SDL_RWread((SDL_RWops*)fd, buf, 1, size); |
} |
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static toff_t tiff_seek(thandle_t fd, toff_t offset, int origin) |
{ |
return SDL_RWseek((SDL_RWops*)fd, offset, origin); |
} |
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static tsize_t tiff_write(thandle_t fd, tdata_t buf, tsize_t size) |
{ |
return SDL_RWwrite((SDL_RWops*)fd, buf, 1, size); |
} |
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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; |
} |
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static toff_t tiff_size(thandle_t fd) |
{ |
Uint32 save_pos; |
toff_t size; |
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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; |
} |
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int IMG_isTIF(SDL_RWops* src) |
{ |
TIFF* tiff; |
TIFFErrorHandler prev_handler; |
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/* Suppress output from libtiff */ |
prev_handler = TIFFSetErrorHandler(NULL); |
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/* 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); |
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/* Reset the default error handler, since it can be useful for info */ |
TIFFSetErrorHandler(prev_handler); |
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/* If it's not a TIFF, then tiff will be NULL. */ |
if(!tiff) |
return 0; |
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/* Free up any dynamically allocated memory libtiff uses */ |
TIFFClose(tiff); |
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return 1; |
} |
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SDL_Surface* IMG_LoadTIF_RW(SDL_RWops* src) |
{ |
TIFF* tiff; |
SDL_Surface* surface = NULL; |
Uint32 img_width, img_height; |
Uint32 Rmask, Gmask, Bmask, Amask, mask; |
Uint32 x, y; |
Uint32 half; |
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/* 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; |
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/* Retrieve the dimensions of the image from the TIFF tags */ |
TIFFGetField(tiff, TIFFTAG_IMAGEWIDTH, &img_width); |
TIFFGetField(tiff, TIFFTAG_IMAGELENGTH, &img_height); |
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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; |
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if(!TIFFReadRGBAImage(tiff, img_width, img_height, surface->pixels, 0)) |
return NULL; |
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/* libtiff loads the image upside-down, flip it back */ |
half = img_height / 2; |
for(y = 0; y < half; y++) |
{ |
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); |
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return surface; |
} |
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#else |
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/* See if an image is contained in a data source */ |
int IMG_isTIF(SDL_RWops *src) |
{ |
return(0); |
} |
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/* Load a TIFF type image from an SDL datasource */ |
SDL_Surface *IMG_LoadTIF_RW(SDL_RWops *src) |
{ |
return(NULL); |
} |
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#endif /* LOAD_TIF */ |