Bouncing shapes

[David JonesK]

hi, I really hope someone can help me with this, i'm trying to create a program which draws a triangle and then the triangle bounces around within a box, for example the shape keeps moving up till it hits the top of the frame then moves in another direction.
I have a program which bounces a ball but I can't change it to bounce any other shape, please can someone help me with this!
Here is the ball program:
import java.awt.*;
import java.applet.Applet;
public class OriginalBall extends Applet
{
/*
Written November 2001
Illustrates simple animation of a grapics object and uses
Thread.sleep () for producing a simple time delay
*/
private int x = 52, xChange = 5; // initial positions plus movement increment
private int y = 12, yChange = 5;
private int diameter = 10; // diameter of ball
private int rectLeftX = 50, rectRightX = 250; // board border coordinates
private int rectTopY = 10, rectBottomY = 180;
public void paint (Graphics g)
{
// draw a board for the game
g.drawRect (rectLeftX, rectTopY, rectRightX - rectLeftX, rectBottomY - rectTopY);
g.setColor (Color.lightGray);
g.fillRect ((rectLeftX+1), (rectTopY+1), (rectRightX-rectLeftX-1), (rectBottomY-rectTopY-1));
for (int n = 1; n < 120; n++) // set up game period loop
{
g.setColor (Color.lightGray); // make ball invisible at original position
g.fillOval(x, y, diameter, diameter);
// check for boundaries and reverse direction if reached
if (x + xChange <= rectLeftX) // left border reached
xChange = -xChange;
else if (x + xChange + diameter >= rectRightX) // right border reached
xChange = -xChange;
else if (y + yChange <= rectTopY) // top border reached
yChange = -yChange;
else if (y + yChange + diameter >= rectBottomY) // bottom border reached
yChange = -yChange;
x = x + xChange; // move ball
y = y + yChange;
g.setColor(Color.red); // make ball visible at new position
g.fillOval (x, y, diameter, diameter);
try
{
Thread.sleep (50); // delay for n ticks
}
catch (InterruptedException e) // must have this exception handler
{
// do nothing
}
}
}
}

[Craig Wood]

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.Timer;
 
public class MotionTest
{
    public static void main(String[] args)
    {
         BouncingTriangle triangle = new BouncingTriangle();
         JFrame f = new JFrame("Bouncing Triangle");
         f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         f.getContentPane().add(triangle.getUIPanel(), "North");
         f.getContentPane().add(triangle);
         f.setSize(400,300);
         f.setLocation(200,200);
         f.setVisible(true);
    }
}
 
class BouncingTriangle extends JPanel
{
    Animator animator;
    Polygon triangle;
    Ellipse2D pointOfImpact;
    Color impactColor;
    Timer timer;
    boolean firstTime, collision;
 
    public BouncingTriangle()
    {
        firstTime = true;
        impactColor = new Color(190,150,10,75);
        animator = new Animator();
        timer = new Timer(25, animator);
        setBackground(Color.white);
    }
 
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        int width = getWidth();
        int height = getHeight();
        if(firstTime)
            createTriangle(width, height);
        g2.draw(triangle);
        if(collision)
        {
            g2.setPaint(impactColor);
            g2.fill(pointOfImpact);
        }
    }
 
    private class Animator implements ActionListener
    {
        int xSpeed = 2;
        int ySpeed = 3;
 
        public void actionPerformed(ActionEvent e)
        {
            checkBoundries();
            triangle.translate(xSpeed, ySpeed);
            repaint();
        }
 
        private void checkBoundries()
        {
            collision = false;
            Rectangle r = triangle.getBounds();
            if(r.x + xSpeed < 0 || r.x + r.width + xSpeed > getWidth())
            {
                xSpeed *= -1;
                collision = true;
            }
            if(r.y + ySpeed < 0 || r.y + r.height + ySpeed > getHeight())
            {
                ySpeed *= -1;
                collision = true;
            }
            if(collision)
                processCollision(r);
        }
 
        private void processCollision(Rectangle r)
        {
            int xDia = 25, yDia = 25;
            int x = r.x + r.width/2;
            int y = r.y;
            if(r.x - xSpeed < 0)
            {
                x = r.x;
                y = r.y + r.height;
            }
            if(r.x + r.width - xSpeed > getWidth())
            {
                x = r.x + r.width;
                y = r.y + r.height;
            }
            if(r.y + r.height - ySpeed > getHeight())
            {
                y = r.y + r.height;
                xDia = r.width;
            }
            pointOfImpact = new Ellipse2D.Double(x - xDia/2 + xSpeed,
                                                 y - yDia/2 + ySpeed, xDia, yDia);
            Toolkit.getDefaultToolkit().beep();
        }
    }
 
    private void createTriangle(int w, int h)
    {
        int R = Math.min(w, h)/5;
        int[][] xy = generateShapeArrays(R, w/2, h/2);
        triangle = new Polygon(xy[0], xy[1], 3);
        firstTime = false;
        timer.start();
    }
 
    private int[][] generateShapeArrays(int R, int cx, int cy)
    {
        int[] x = new int[3];
        int[] y = new int[3];
        int radians = 0;
        for(int i = 0; i < 3; i++)
        {
            x[i] = cx + (int)(R * Math.sin(radians*Math.PI/3));
            y[i] = cy - (int)(R * Math.cos(radians*Math.PI/3));
            radians += 2;
        }
        y[2] = y[1];                  // ensure base is level
        return new int[][] {x,y};
    }
 
    public JPanel getUIPanel()
    {
        SpinnerNumberModel timerModel = new SpinnerNumberModel(25, 10, 150, 1);
        final JSpinner timerSpinner = new JSpinner(timerModel);
        SpinnerNumberModel xSpeedModel = new SpinnerNumberModel(2, 1, 5, 1);
        final JSpinner xSpeedSpinner = new JSpinner(xSpeedModel);
        SpinnerNumberModel ySpeedModel = new SpinnerNumberModel(3, 1, 5, 1);
        final JSpinner ySpeedSpinner = new JSpinner(ySpeedModel);
        ChangeListener l = new ChangeListener()
        {
            public void stateChanged(ChangeEvent e)
            {
                JSpinner spinner = (JSpinner)e.getSource();
                int value = ((Integer)spinner.getValue()).intValue();
                if(spinner == timerSpinner)
                    timer.setDelay(value);
                if(spinner == xSpeedSpinner)
                    animator.xSpeed = value;
                if(spinner == ySpeedSpinner)
                    animator.ySpeed = value;
                repaint();
            }
        };
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.weightx = 1.0;
        gbc.insets = new Insets(2,2,2,2);
        addToPanel(new JLabel("delay"),  timerSpinner,  l, panel, gbc);
        addToPanel(new JLabel("xSpeed"), xSpeedSpinner, l, panel, gbc);
        addToPanel(new JLabel("ySpeed"), ySpeedSpinner, l, panel, gbc);
        return panel;
    }
 
    private void addToPanel(JLabel label, JSpinner s, ChangeListener l,
                            JPanel p, GridBagConstraints gbc)
    {
        gbc.anchor = gbc.EAST;
        p.add(label, gbc);
        gbc.anchor = gbc.WEST;
        p.add(s, gbc);
        s.addChangeListener(l);
    }
}

[ March 11, 2004: Message edited by: Craig Wood ]
[ March 11, 2004: Message edited by: Craig Wood ]

[David JonesK]

Thanks a lot, that was great