/*
 * lpscl.c: Log Polar Mapping.
 *
 *   May.15,'94. Oshiro.
 *   Oct. 6,'94. Oshiro. 入力ファイルの形式を ppm にした．
 */

static char rcsid[]="$Id: lpscl.c,v 1.1 1995/05/10 18:19:27 oshiro Exp oshiro $";

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

#define EXIT_SUCCESS 0
#define EXIT_FAILURE 1

int main(int argc, char **argv)
{
	FILE *fp;
	int width, height;
	int trans_length;
	long x, y;
	int uwidth, vwidth;
	int img_type, depth;
	long u, v;
	long len;
	char *data;
	char *fname;
	
	if (argc != 3 && argc != 4) {
		fprintf(stderr, "Usage: lpscl lpwidth lpheight [infile]\n");
		exit(EXIT_FAILURE);
	}
	vwidth=atoi(argv[1]);
	uwidth=atoi(argv[2]);
	if (argc==4) {
		fname=argv[3];
		fp=OpenAndCheckPPMFile(fname, &img_type, &width, &height, &depth);
		if (fp==NULL) {
			fprintf(stderr, "lpscl: Incorrect ppm file (%s).\n",
				fname);
			exit(EXIT_FAILURE);
		}
	} else {
		fp=stdin;
		if (CheckPPMFile(fp, &img_type, &width, &height, &depth)!=0) {
			fprintf(stderr, "lpscl: Incorrect ppm file (stdin).\n");
			exit(EXIT_FAILURE);
		}
	}

	data=malloc(sizeof(char)*(long)width*height*3);
	if (data == NULL) {
		fprintf(stderr, "lpscl: Fatal: Not enough memory.\n");
		fclose(fp);
		exit(EXIT_FAILURE);
	}
	len=fread(data, sizeof(char), (long)width*height*3, fp);
	fclose(fp);
	if (len < width*height) {
		fprintf(stderr, "lpscl: Warning: Not enough data.\n");
	}
	
	trans_length=((width>height)? width:height)/2;
	printf("P6\n%d %d\n255\n", uwidth, vwidth);
	for (v=0; v<vwidth; v++) {
		for (u=0; u<uwidth; u++) {
			x=(int)(exp((double)u/uwidth*log(trans_length))
				*cos(((double)v-vwidth/2)/vwidth*atan2(1,1)*4*2));
			y=(int)(exp((double)u/uwidth*log(trans_length))
				*sin(((double)v-vwidth/2)/vwidth*atan2(1,1)*4*2));
			if (x<=-width/2 || x>=width/2 || y<=-height/2 || y>=height/2) {
				putchar(0);
				putchar(0);
				putchar(0);
				continue;
			}
			y+=height/2;
			y=height-y-1;
			x+=width/2;
			putchar(data[y*(width*3) + x*3  ]);
			putchar(data[y*(width*3) + x*3+1]);
			putchar(data[y*(width*3) + x*3+2]);
		}
	}
	
	return(EXIT_SUCCESS);
}