Help with getting new points

Hi guys,

I am doing a project that needs me to draw a triangle on the screen and rotate it. The rotate part is fine but after i rotate the shape i could not get the new cordinates of the new triangle.Please advice thanks.

i tried to cast the shape back to polygon and get the points but i had a cast class exception and that is the last solution i have got please help thanks in advance
this is the code:

regards
Huatz

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
 
public class Xpoints extends JPanel {
    Rectangle r = new Rectangle(75,90,240,160);
    JLabel xLabel;
    JLabel yLabel;
 
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setPaint(Color.blue);
        g2.draw(r);
        double x = r.getCenterX();
        double y = r.getCenterY();
        AffineTransform at =
            AffineTransform.getRotateInstance(Math.PI/4, x, y);
        g2.setPaint(Color.red);
        g2.draw(at.createTransformedShape(r));
        showXpoints(at);
    }
 
    private void showXpoints(AffineTransform at) {
        // Transform all/any vertex coordinates of r with at.
        double[] coords = {
            r.x, r.y,                  r.getMaxX(), r.y,
            r.getMaxX(), r.getMaxY(),  r.x, r.getMaxY()
        };
        double[] xformCoords = new double[coords.length];
        at.transform(coords, 0, xformCoords, 0, coords.length/2);
        System.out.println("Transformed coordinates for vertices of r:");
        for(int i = 0; i < xformCoords.length; i += 2) {
            System.out.printf("[%5.1f, %5.1f]%n",
                               xformCoords[i], xformCoords[i+1]);
        }
 
        // Another way to get the vertices of the transformed shape.
        System.out.println("Show vertices of transformed shape:");
        PathIterator pit = r.getPathIterator(at);
        coords = new double[2];
        while(!pit.isDone()) {
            int type = pit.currentSegment(coords);
            switch(type) {
                case PathIterator.SEG_MOVETO:
                case PathIterator.SEG_LINETO:
                    System.out.printf("[%5.1f, %5.1f]%n",
                                       coords[0], coords[1]);
            }
            pit.next();
        }
        System.out.println("Cast for transformedShape = " +
                            at.createTransformedShape(r).getClass().getName());
    }
 
    private JPanel getUIpanel() {
        xLabel = new JLabel();
        yLabel = new JLabel();
        Dimension d = new Dimension(45,25);
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(2,2,2,2);
        gbc.weightx = 1.0;
        addComponents("x =", xLabel, panel, gbc, d);
        addComponents("x =", yLabel, panel, gbc, d);
        return panel;
    }
 
    private void addComponents(String s, JLabel label, Container c,
                               GridBagConstraints gbc, Dimension d) {
        gbc.anchor = GridBagConstraints.EAST;
        c.add(new JLabel(s), gbc);
        label.setPreferredSize(d);
        gbc.anchor = GridBagConstraints.WEST;
        c.add(label, gbc);
    }
 
    public static void main(String[] args) {
        Xpoints test = new Xpoints();
        test.addMouseMotionListener(test.mml);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(test);
        f.add(test.getUIpanel(), "Last");
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
 
    private MouseMotionListener mml = new MouseMotionAdapter() {
        public void mouseMoved(MouseEvent e) {
            xLabel.setText(String.valueOf(e.getX()));
            yLabel.setText(String.valueOf(e.getY()));
        }
    };
}

thanks for the help

thanks for the help