libgd/src/gdparttopng.c

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>		/* For atoi */
#include "gd.h"

/* A short program which converts a .png file into a .gd file, for
   your convenience in creating images on the fly from a
   basis image that must be loaded quickly. The .gd format
   is not intended to be a general-purpose format. */

int
main (int argc, char **argv)
{
	gdImagePtr im;
	FILE *in, *out;
	int x, y, w, h;

	if (argc != 7) {
		fprintf (stderr,
		         "Usage: gdparttopng filename.gd filename.png x y w h\n");
		exit (1);
	}
	in = fopen (argv[1], "rb");
	if (!in) {
		fprintf(stderr, "Input file does not exist!\n");
		exit (1);
	}

	x = atoi (argv[3]);
	y = atoi (argv[4]);
	w = atoi (argv[5]);
	h = atoi (argv[6]);

	printf ("Extracting from (%d, %d), size is %dx%d\n", x, y, w, h);

	im = gdImageCreateFromGd2Part (in, x, y, w, h);
	fclose (in);
	if (!im) {
		fprintf(stderr, "Input is not in GD2 format!\n");
		exit (1);
	}
	out = fopen (argv[2], "wb");
	if (!out) {
		fprintf(stderr, "Output file cannot be written to!\n");
		gdImageDestroy (im);
		exit (1);
	}
	gdImagePng (im, out);
	fclose (out);
	gdImageDestroy (im);

	return 0;
}