175 lines
4.4 KiB
C
175 lines
4.4 KiB
C
/*
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IMGLIB: An example image loading library for use with SDL
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Copyright (C) 1999 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 Library General Public
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License as published by the Free Software Foundation; either
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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,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with this library; if not, write to the Free
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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Sam Lantinga
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5635-34 Springhouse Dr.
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Pleasanton, CA 94588 (USA)
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slouken@devolution.com
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5/29/2000: TIFF loader written. Mark Baker (mbaker@0x7a69.net)
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2000-07-28: Fixed two off-by one bugs in reversal loop and made it work on
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big-endian machines (Mattias)
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2000-08-09: Removed alpha inversion (Mattias)
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*/
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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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/*
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* These are the thunking routine to use the SDL_RWops* routines from
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* libtiff's internals.
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*/
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static tsize_t tiff_read(thandle_t fd, tdata_t buf, tsize_t size)
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{
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return SDL_RWread((SDL_RWops*)fd, buf, 1, size);
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}
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static toff_t tiff_seek(thandle_t fd, toff_t offset, int origin)
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{
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return SDL_RWseek((SDL_RWops*)fd, offset, origin);
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}
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static tsize_t tiff_write(thandle_t fd, tdata_t buf, tsize_t size)
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{
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return SDL_RWwrite((SDL_RWops*)fd, buf, 1, size);
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}
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static int tiff_close(thandle_t fd)
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{
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/*
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* We don't want libtiff closing our SDL_RWops*, but if it's not given
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* a routine to try, and if the image isn't a TIFF, it'll segfault.
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*/
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return 0;
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}
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static toff_t tiff_size(thandle_t fd)
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{
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Uint32 save_pos;
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toff_t size;
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save_pos = SDL_RWtell((SDL_RWops*)fd);
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SDL_RWseek((SDL_RWops*)fd, 0, SEEK_END);
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size = SDL_RWtell((SDL_RWops*)fd);
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SDL_RWseek((SDL_RWops*)fd, save_pos, SEEK_SET);
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return size;
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}
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int IMG_isTIF(SDL_RWops* src)
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{
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TIFF* tiff;
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TIFFErrorHandler prev_handler;
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/* Suppress output from libtiff */
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prev_handler = TIFFSetErrorHandler(NULL);
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/* Attempt to process the given file data */
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/* turn off memory mapped access with the m flag */
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tiff = TIFFClientOpen("SDL_image", "rm", (thandle_t)src,
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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 */
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TIFFSetErrorHandler(prev_handler);
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/* If it's not a TIFF, then tiff will be NULL. */
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if(!tiff)
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return 0;
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/* Free up any dynamically allocated memory libtiff uses */
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TIFFClose(tiff);
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return 1;
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}
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SDL_Surface* IMG_LoadTIF_RW(SDL_RWops* src)
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{
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TIFF* tiff;
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SDL_Surface* surface = NULL;
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Uint32 img_width, img_height;
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Uint32 Rmask, Gmask, Bmask, Amask, mask;
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Uint32 x, y;
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Uint32 half;
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/* turn off memory mapped access with the m flag */
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tiff = TIFFClientOpen("SDL_image", "rm", (thandle_t)src,
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tiff_read, tiff_write, tiff_seek, tiff_close, tiff_size, NULL, NULL);
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if(!tiff)
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return NULL;
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/* Retrieve the dimensions of the image from the TIFF tags */
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TIFFGetField(tiff, TIFFTAG_IMAGEWIDTH, &img_width);
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TIFFGetField(tiff, TIFFTAG_IMAGELENGTH, &img_height);
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Rmask = 0x000000FF;
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Gmask = 0x0000FF00;
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Bmask = 0x00FF0000;
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Amask = 0xFF000000;
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surface = SDL_AllocSurface(SDL_SWSURFACE, img_width, img_height, 32,
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Rmask, Gmask, Bmask, Amask);
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if(!surface)
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return NULL;
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if(!TIFFReadRGBAImage(tiff, img_width, img_height, surface->pixels, 0))
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return NULL;
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/* libtiff loads the image upside-down, flip it back */
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half = img_height / 2;
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for(y = 0; y < half; y++)
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{
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Uint32 *top = (Uint32 *)surface->pixels + y * surface->pitch/4;
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Uint32 *bot = (Uint32 *)surface->pixels
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+ (img_height - y - 1) * surface->pitch/4;
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for(x = 0; x < img_width; x++)
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{
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Uint32 tmp = top[x];
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top[x] = bot[x];
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bot[x] = tmp;
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}
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}
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TIFFClose(tiff);
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return surface;
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}
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#else
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/* See if an image is contained in a data source */
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int IMG_isTIF(SDL_RWops *src)
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{
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return(0);
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}
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/* Load a TIFF type image from an SDL datasource */
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SDL_Surface *IMG_LoadTIF_RW(SDL_RWops *src)
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{
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return(NULL);
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}
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#endif /* LOAD_TIF */
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