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#include "image.h"
#include <stdlib.h>
image_t *imagecreate( int width, int height )
{
int i;
image_t *image;
image = (image_t*)malloc( sizeof(image_t) );
image->width = width;
image->height = height;
image->xbytes = (width + 7) / 8;
image->bitmap = (png_bytep)calloc( image->xbytes, height );
image->rowps = (png_bytep*)malloc( sizeof( png_bytep ) * height );
for( i = 0; i < height; i ++ )
{
image->rowps[i] = image->bitmap + (i * image->xbytes);
}
return image;
}
void imagedestroy( image_t *image )
{
free( image->bitmap );
free( image->rowps );
free( image );
image = NULL;
}
static inline int imagegetpixel( image_t *image, int x, int y )
{
return (image->bitmap[image->xbytes * y + (x/8)] & (0x80 >> (x & 7))) ? 1 : 0;
}
static inline void imagesetpixel( image_t *image, int x, int y, int c )
{
if( c )
{
image->bitmap[image->xbytes * y + (x/8)] |= (0x80 >> (x & 7));
}
else
{
image->bitmap[image->xbytes * y + (x/8)] &= ~(0x80 >> (x & 7));
}
}
/* flip image 180 degrees */
void imageflip( image_t *image )
{
int x, x2, y, y2, c, c2;
for( y = 0; y < (image->height) >> 1; ++y )
{
y2 = image->height - 1 - y;
for( x = 0; x < image->width; ++x )
{
/* exchage pixel from top left with bottom right and so on */
x2 = image->width - 1 - x;
c = imagegetpixel( image, x, y );
c2 = imagegetpixel( image, x2, y2 );
imagesetpixel( image, x, y, c2 );
imagesetpixel( image, x2, y2, c );
}
}
if( image->height & 1 )
{
/* odd number of lines, so mirror center line */
y = image->height/2;
for( x = 0; x < (image->width) >> 1; ++x )
{
x2 = image->width - 1 - x;
c = imagegetpixel( image, x, y );
c2 = imagegetpixel( image, x2, y );
imagesetpixel( image, x, y, c2 );
imagesetpixel( image, x2, y, c );
}
}
}
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