forked from 50m30n3/QTC
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ppm.c
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ppm.c
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/*
* QTC: ppm.c (c) 2011, 2012 50m30n3
*
* This file is part of QTC.
*
* QTC is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* QTC 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with QTC. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "image.h"
#include "ppm.h"
/*******************************************************************************
* Function to load a ppm file into an image structure *
* *
* image is the uninitialized image structure to load into *
* filename is the file name of the image file *
* *
* Returns 0 on failure, 1 on success *
*******************************************************************************/
int ppm_read( struct image *image, char *filename )
{
FILE *ppm;
char buffer[256];
int width, height, maxval;
int i, j;
unsigned char *rawpixels;
unsigned int *pixels;
if( filename == NULL )
{
ppm = stdin;
}
else
{
if( strcmp( filename, "-" ) == 0 )
{
ppm = stdin;
}
else
{
ppm = fopen( filename, "rb" );
}
}
if( ppm != NULL )
{
if( fgets( buffer, sizeof( buffer ) - 1, ppm ) == NULL )
{
fputs( "ppm_read: Cannot read file\n", stderr );
if( ppm != stdin )
fclose( ppm );
return 0;
}
if( strcmp( buffer, "P6\n" ) != 0 )
{
fputs( "ppm_read: File is not a ppm file\n", stderr );
if( ppm != stdin )
fclose( ppm );
return 0;
}
do
{
if( fgets( buffer, sizeof( buffer ) - 1, ppm ) == NULL )
{
fputs( "ppm_read: Cannot read file\n", stderr );
if( ppm != stdin )
fclose( ppm );
return 0;
}
}
while( buffer[0] == '#' );
if( sscanf( buffer, "%i %i\n", &width, &height ) != 2 )
{
fputs( "ppm_read: Cannot read image dimension\n", stderr );
if( ppm != stdin )
fclose( ppm );
return 0;
}
do
{
if( fgets( buffer, sizeof( buffer ) - 1, ppm ) == NULL )
{
fputs( "ppm_read: Cannot read file\n", stderr );
if( ppm != stdin )
fclose( ppm );
return 0;
}
}
while( buffer[0] == '#' );
if( sscanf( buffer, "%i\n", &maxval ) != 1 )
{
fputs( "ppm_read: Cannot read maximum pixel value\n", stderr );
if( ppm != stdin )
fclose( ppm );
return 0;
}
if( maxval != 255 )
{
fputs( "ppm_read: Unsupported bitdepth\n", stderr );
if( ppm != stdin )
fclose( ppm );
return 0;
}
image->width = width;
image->height = height;
image->colordiff = 0;
image->transform = 0;
image->bgra = 0;
rawpixels = malloc( sizeof( unsigned char ) * width * height * 3 + 1 );
if( rawpixels != NULL )
{
if( fread( rawpixels, sizeof( *(rawpixels) ), width*height*3, ppm ) != (unsigned int)(width*height*3) )
{
fputs( "ppm_read: Short read on image data\n", stderr );
free( rawpixels );
if( ppm != stdin )
fclose( ppm );
return 0;
}
}
else
{
perror( "ppm_read" );
if( ppm != stdin )
fclose( ppm );
return 0;
}
image->pixels = malloc( sizeof( unsigned char ) * width * height * 4 );
if( image->pixels == NULL )
{
perror( "ppm_read" );
free( rawpixels );
if( ppm != stdin )
fclose( ppm );
return 0;
}
pixels = (unsigned int *)image->pixels;
j = 0;
for( i=0; i<width*height*3; i+=3 )
{
pixels[j++] = (*((unsigned int *)(rawpixels+i)))&0x00FFFFFF;
}
free( rawpixels );
if( ppm != stdin )
fclose( ppm );
return 1;
}
else
{
perror( "ppm_read" );
return 0;
}
}
/*******************************************************************************
* Function to write an image structure into a ppm file *
* *
* image is the image to be written *
* filename is the file name of the new image file *
* *
* Returns 0 on failure, 1 on success *
*******************************************************************************/
int ppm_write( struct image *image, char *filename )
{
FILE *ppm;
int i, j;
unsigned char *rawpixels;
unsigned int *pixels;
if( filename == NULL )
{
ppm = stdout;
}
else
{
if( strcmp( filename, "-" ) == 0 )
{
ppm = stdout;
}
else
{
ppm = fopen( filename, "wb" );
}
}
if( ppm != NULL )
{
rawpixels = malloc( sizeof( unsigned char ) * image->width * image->height * 3 + 1 );
if( rawpixels == NULL )
{
perror( "ppm_write" );
if( ppm != stdin )
fclose( ppm );
return 0;
}
pixels = (unsigned int *)image->pixels;
j = 0;
for( i=0; i<image->width*image->height*3; i+=3 )
{
(*((unsigned int *)(rawpixels+i))) = pixels[j++];
}
fprintf( ppm, "P6\n%i %i\n255\n", image->width, image->height );
if( fwrite( rawpixels, sizeof( *(rawpixels) ), image->width*image->height*3, ppm ) != (unsigned int)(image->width*image->height*3) )
{
fputs( "ppm_write: Short write on image data\n", stderr );
free( rawpixels );
if( ppm != stdout )
fclose( ppm );
return 0;
}
free( rawpixels );
if( ppm != stdout )
fclose( ppm );
return 1;
}
else
{
perror( "ppm_write" );
return 0;
}
}