/*******************************************************************

    Program:  a2ppm.c            Eric Weeks  8-1-96


6-18-95:  a2ps.c started from mat2las.c; designed for (perhaps) CA's
          added in -xy options
8-01-96:  a2ppm.c started from a2ps.c

http://www.physics.emory.edu/~weeks/

 *******************************************************************/
#include <stdio.h>

char *prgname;

main(argc,argv)
int argc;
char **argv;
{
	int i,j,c,count;
	double atof(),blah;
	int hres,vres,invert;
	unsigned char pixel;
	FILE *fp, *fopen();
	extern int optind;
	extern char *optarg;

	invert = 0;
	count = 0;
	while ((c = getopt(argc, argv, "hi")) != EOF)
		switch (c)
		{
        case 'h':
fprintf(stderr,"Usage: a2ppm [options] [<] [file] > file.ppm\n");
fprintf(stderr,"  -h   : this help message\n");
fprintf(stderr,"  -i   : invert colors [default:no]\n");
                   exit(1);
                   break;
	case 'i': invert = 1;
			break;
        }

	argc -= (optind-1) ; argv += (optind-1) ;
	fp = (argc > 1) ? fopen(*++argv, "r") : stdin;


	fscanf(fp,"%ld %ld",&hres,&vres);

	/*  Write the necessary starting junk  */
	printf("P5\n#Created by a2ppm, written by Eric R. Weeks\n");
	printf("%d %d\n255\n",hres,vres);

/*  Now, read in the rest of the file, converting each character
    to hexadecimal and punching to std. output.  */

	for(j=0;j<vres;++j)  {
		for(i=0;i<hres;++i)  {
			if (fscanf(fp,"%ld",&c) != 1)  {
				fprintf(stderr,"file ended suddenly!");
				j = vres; i = hres;
			}
			pixel = c;
			if (invert==1)  pixel = 255-pixel;
			if (pixel<10)  count++;
			fputc((char)pixel,stdout);
			/* pixel = 255 means white (no ink) */
		}
	}

	blah = (1.0*count/(1.0*hres*vres));
	if (blah>.3)  {
		fprintf(stderr,"%5.1f percent of picture is black,\nyou might want to consider using -i option!\n\nUse 'cancel' command to stop laserwriter output.\n",blah*100.0);
	}


}