import java.awt.Rectangle;
import java.awt.Color;
import java.awt.Point;

public class Schleife {

    public static void main(String[] args) {
        GraphicsWindow gw = new GraphicsWindow();

        drawGradient(gw);
        
        gw.mouseClick();
        System.exit(0);
    }

    private static void drawGradient(GraphicsWindow gw) {
        Color fg = gw.getColor();
        for (Point p = new Point(0,0); p.y <= 480; p.move(0, p.y + 1)) // gw.GetWidth would have been nice
            {
                for (;p.x <= 640; p.move(p.x + 1, p.y))
                         {
                             gw.setColor(f(p.x, p.y) <= 0 ? Color.red : color(p.x, p.y));
                             // System.out.format("%s in %s\n", p.toString(), gw.getColor().toString()); // DEBUG
                             gw.drawPoint(p);
                         }
            }
        gw.setColor(fg);
    }

    private static double f(int x, int y) {
        double xprime = (x - 200) / 120.0;
        double yprime = (200 - y) / 100.0;
        return Math.pow(xprime * xprime + yprime * yprime - 1, 3) - (xprime * xprime * yprime * yprime * yprime);
          // pow is comparatively expensive (at least it would be if this were C ;) )
    }

    private static Color color(int x, int y) {
        // System.out.format("(%d, %d)\n", x, y); // DEBUG
        double g = 0.15 * (1200 - x - y);
        double b = 0.15 * (x + y);
        return new Color((int) 0, (int) g, (int) b);
        /* Why can’t we have nice things? Like proper type signatures?
         * We introduce some error by truncating to integer -- We deemed this to be of no moment.
         */
    }

}