package sample.svg;
import static util.SVGUtil.*;

public class SpaceFillingTree {
	private static int color;
	private static int dcolor = 1;

	private static double aux(int n) {
	    double r = 1;
	    int i;
	    for (i=0; i<n; i++) {
	        r /= 2;
	    }
	    return r;
	}

	private static void spaceFillingTree(int n, double x0, double y0, double x2, double y2) {
	    if (n==0) {
	        return;
	    }  else {
	        double d = aux(n+1);
	        double xA = (0.5+d)*x0+(0.5-d)*x2, yA = (0.5+d)*y0+(0.5-d)*y2;
	        double xB = (0.5-d)*x0+(0.5+d)*x2, yB = (0.5-d)*y0+(0.5+d)*y2;
	        double x1 = (x0+x2)/2, y1 = (y0+y2)/2;
	        line(xA, yA, xB, yB);
	        stroke(color = rotateH360(color, dcolor));
	        line(xA, yB, xB, yA);
	        stroke(color = rotateH360(color, dcolor));
	        spaceFillingTree(n-1, x0, y0, x1, y1);
	        spaceFillingTree(n-1, x1, y0, x2, y1);
	        spaceFillingTree(n-1, x0, y1, x1, y2);
	        spaceFillingTree(n-1, x1, y1, x2, y2);
	    }
	}

	public static void main(String[] args) {
	    start();
	    stroke(color = hsb360(0, 100, 100));
	    strokeWeight(0.5);
	    noFill();
	    spaceFillingTree(6, 40, 30, 257, 180);
	    finish();
	}
}