/* imgbm_kill_60S.c
 *
 * quick program to read from stdin an imgbm file, and write to stdout
 * only those points that are N of 60S.
 *
 * Used to remove GMT coastline and put in SCAR coastline
 *
 * whfs 10 jun 1997
 */

#include <stdio.h>
#include <math.h>

struct IMGPAIR {
        int     index;
        int     value;
};

main (argc, argv)
int	argc;
char	**argv;
{

	struct IMGPAIR p;
	int	nin = 0, nout = 0;
	int	maxindex = 58665600;	/* 60S index value.  */

	if (argc != 1) {
		fprintf(stderr,"imgbm_kill_60S pass from stdin to stdout imgbm points N of 60S.\n");
		fprintf(stderr,"usage:  imgbm_kill_60S < input.imgbm > output.imgbm\n");
		exit(-1);
	}

	while ( (fread( (char *)&p, 8, 1, stdin)) == 1) {
		nin++;
		if (p.index < maxindex) {
			nout++;
			if ( (fwrite( (char *)&p, 8, 1, stdout)) != 1) {
				fprintf(stderr, "imgbm_kill_60S:  Error writing out at %d %d\n", nin, nout);
				exit(-1);
			}
		}
	}

	fprintf(stderr,"imgbm_kill_60S:  Read %d and wrote %d points.\n", nin, nout);
	exit(0);
}