flow_code/C/colortest.cpp

// colortest.cpp

// create a test image showing the color encoding

static char usage[] = "usage: %s range outimage [size]\n";

# include <stdio.h>
# include <math.h>
#include "imageLib.h"
#include "colorcode.h"

int main(int argc, char **argv)
{
    int verbose = 1;
    if (argc < 3) {
	fprintf(stderr, usage, argv[0]);
	exit(1);
    }
    int optind = 1;
    float truerange = atof(argv[optind++]);
    char *outname = argv[optind++];
    int size = optind < argc ? atoi(argv[optind++]) : 151;

    float range = 1.04 * truerange; // make picture a bit bigger to show out-of-range coding
    try {
	CShape sh(size, size, 3);
	CByteImage out(sh);

	int s2 = size/2;
	for (int y = 0; y < size; y++) {
	    for (int x = 0; x < size; x++) {
		float fx = (float)x / (float)s2 * range - range;
		float fy = (float)y / (float)s2 * range - range;
		if (x == s2 || y == s2) // make black coordinate axes
		    continue;
		uchar *pix = &out.Pixel(x, y, 0);
		//fx = rintf(fx);
		//fy = rintf(fy);
		computeColor(fx/truerange, fy/truerange, pix);
	    }
	}
	int ir = (int)truerange;
	int ticksize = size < 120 ? 1 : 2;
	for (int k = -ir; k <= ir; k++) {
	    int ik = (int)(k / range * s2) + s2;
	    for (int t = -ticksize; t <= ticksize; t++) {
		uchar *pix;
		pix = &out.Pixel(ik, s2 + t, 0); pix[0] = pix[1] = pix[2] = 0;
		pix = &out.Pixel(s2 + t, ik, 0); pix[0] = pix[1] = pix[2] = 0;
	    }
	}

	WriteImageVerb(out, outname, verbose);
    }
    catch (CError &err) {
	fprintf(stderr, err.message);
	fprintf(stderr, "\n");
	exit(1);
    }
    return 0;
}