Archived from Ken Turkowski Open Source Repository http://www.worldserver.com/turk/opensource/

ZonePlate.c

/* Copyright (C) 1978-1995 Ken Turkowski. <turk@computer.org>
 *
 * All rights reserved.
 *
 * Warranty Information
 *  Even though I have reviewed this software, I make no warranty
 *  or representation, either express or implied, with respect to this
 *  software, its quality, accuracy, merchantability, or fitness for a
 *  particular purpose.  As a result, this software is provided "as is,"
 *  and you, its user, are assuming the entire risk as to its quality
 *  and accuracy.
 *
 * This code may be used and freely distributed as long as it includes
 * this copyright notice and the above warranty information.
 */

#include <stdio.h>
#include <stdlib.h>
#include <fp.h>
#define PI 3.1415926535898

unsigned char sineTab[256];


/*******************************************************************************
 * ZonePlate
 *******************************************************************************/

static void
ZonePlate(FILE *fd, long width, long height, long scale)
{
	long cX, cY;
	long i, j;
	long x, y;
	long d;
	
	cX = width / 2;
	cY = height / 2;
	
	for (i = height, y = -cY; i--; y++) {
		for (j = width, x = -cX; j--; x++) {
			d = ((x * x + y * y) * scale) >> 8;
			putc(sineTab[d & 0xFF], fd);
		}
	}
}


/*******************************************************************************
 * MakeSineTab
 *******************************************************************************/

static void
MakeSineTab(void) {
	long i;
	for (i = 0; i < 256; i++) {
		sineTab[i] = 127.5 * sin(PI * (i - 127.5) / 127.5) + 127.5;
	}
}


/*******************************************************************************
 * main
 *******************************************************************************/

int
main(int argc, char **argv)
{
	long width = 0;
	long height = 0;
	long scale = 0;
	char *outFile = NULL;
	FILE *fd;
	
	for (argc--, argv++; argc-- > 0; argv++) {
		if (argv[0][0] == '-') {
			switch (argv[0][1]) {
				case 'w':
					argc--; argv++;
					width = atoi(argv[0]);
					break;
				case 'h':
					argc--; argv++;
					height = atoi(argv[0]);
					break;
				case 's':
					argc--; argv++;
					scale = atoi(argv[0]);
					break;
				case 'o':
					argc--; argv++;
					outFile = argv[0];
					break;
			}
		}
		else {
		}
	}
	
	if (width == 0 || height == 0 || scale == 0 || outFile == NULL) {
		printf("Usage: ZonePlate -w <width> -h <height> -s <scale> -o <outFile>\n");
		exit(1);
	}
	
	if ((fd = fopen(outFile, "wb")) == NULL) {
		printf("Can't open \"%s\"\n", outFile);
		exit(2);
	}
	
	MakeSineTab();
	
	ZonePlate(fd, width, height, scale);
	
	fclose(fd);
	
	return(0);
}