Ellipses.java  
/*
 * @(#)Ellipses.java    1.21 04/07/26
 * 
 * Copyright (c) 2004 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 * 
 * -Redistribution in binary form must reproduce the above copyright notice, 
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL 
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST 
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, 
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY 
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, 
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */

/*
 * @(#)Ellipses.java    1.21 04/07/26
 */

package java2d.demos.Arcs_Curves;

import java.awt.*;
import java.awt.geom.Ellipse2D;
import java2d.AnimatingSurface;


/**
 * Ellipse2D 25 animated expanding ellipses.
 */
public class Ellipses extends AnimatingSurface {

    private static Color colors[] = { Color.blue, Color.cyan, Color.green,
                Color.magenta, Color.orange, Color.pink, Color.red, 
                Color.yellow, Color.lightGray, Color.white };
    private Ellipse2D.Float[] ellipses;
    private double esize[];
    private float estroke[];
    private double maxSize;


    public Ellipses() {
        setBackground(Color.black);
        ellipses = new Ellipse2D.Float[25];
        esize = new double[ellipses.length];
        estroke = new float[ellipses.length];
        for (int i = 0; i < ellipses.length; i++) {
            ellipses[i] = new Ellipse2D.Float();
            getRandomXY(i, 20 * Math.random(), 200, 200);
        }
    }


    public void getRandomXY(int i, double size, int w, int h) {
        esize[i] = size;
        estroke[i] = 1.0f;
        double x = Math.random() * (w-(maxSize/2));
        double y = Math.random() * (h-(maxSize/2));
        ellipses[i].setFrame(x, y, size, size);
    }


    public void reset(int w, int h) {
        maxSize = w/10;
        for (int i = 0; i < ellipses.length; i++ ) {
            getRandomXY(i, maxSize * Math.random(), w, h);
        }
    }


    public void step(int w, int h) {
        for (int i = 0; i < ellipses.length; i++) {
            estroke[i] += 0.025f;
            esize[i]++;
            if (esize[i] > maxSize) {
                getRandomXY(i, 1, w, h);
            } else {
                ellipses[i].setFrame(ellipses[i].getX(), ellipses[i].getY(),
                                     esize[i], esize[i]);
            }
        }
    }


    public void render(int w, int h, Graphics2D g2) {
        for (int i = 0; i < ellipses.length; i++) {
            g2.setColor(colors[i%colors.length]);
            g2.setStroke(new BasicStroke(estroke[i]));
            g2.draw(ellipses[i]);
        }
    }


    public static void main(String argv[]) {
        createDemoFrame(new Ellipses());
    }
}