import java.awt.*;

public class NewBounce extends java.applet.Applet implements Runnable {

    Image ball;
    float current = (float) 0;
    float strength = (float) 1;
    Thread runner;
    int xPosition = 10;
    int xMove = 1;
    int yPosition = -1;
    int ballHeight = 102;
    int ballWidth = 111;
    int height;
    Image workspace;
    Graphics offscreen;

    public void init() {
        workspace = createImage(size().width, size().height);
        offscreen = workspace.getGraphics();
        setBackground(Color.white);
        ball = getImage(getCodeBase(), "tennis.jpg");
    }

    public void paint(Graphics screen) {
        height = size().height - ballHeight;
        if (yPosition == -1)
            yPosition = height;
        offscreen.setColor(Color.white);
        offscreen.fillRect(0,0,size().width,size().height);
        offscreen.drawImage(ball,
            (int) xPosition,
            (int) yPosition,
            this);
        screen.drawImage(workspace, 0, 0, this);
    }

    public void start() {
        if (runner == null) {
            runner = new Thread(this);
            runner.start();
        }
    }

    public void run() {
        while (true) {
            repaint();
            current += (float) 0.1;
            if (current > 3) {
                current = (float) 0;
                strength = (float)(strength * 0.9);
            }
            xPosition += xMove;
            if (xPosition > (size().width - 111))
                xMove *= -1;
            if (xPosition < 1)
                xMove *= -1;
            double bounce = Math.sin(current) * height * strength;
            yPosition = (int) (height - bounce);
            try { Thread.sleep(200); }
            catch (InterruptedException e) { }
        }
    }

    public void stop() {
        if (runner != null) {
            runner.stop();
            runner = null;
        }
    }

    public void update(Graphics screen) {
        paint(screen);
    }
}