Getting a sequence of Point2D objects from a PathIterator?

Question

I would like to be able to take an arc or some other non-straight shape and convert it's geometry into a series of points that (roughly) traverse it. I attempted the following, as an example to see how it would work:
     arc = new Arc2D.Double(50,50,150,150,135,-270,Arc2D.OPEN);
     PathIterator pi = arc.getPathIterator(null);
     double[] coords = new double[6];
     int code;
     while (!pi.isDone()) {
          code = pi.currentSegment(coords);
          switch (code) {
          case PathIterator.SEG_CLOSE:
               System.out.print("Close: ");
               break;
          case PathIterator.SEG_CUBICTO:
               System.out.print("Cubic To: ");
               break;
          case PathIterator.SEG_LINETO:
               System.out.print("Line To: ");
               break;
          case PathIterator.SEG_MOVETO:
               System.out.print("Move To: ");
               break;
          case PathIterator.SEG_QUADTO:
               System.out.print("Quad To: ");
               break;
          default:
               break;
          System.out.println(coords[0] + "," + coords[1] + "   " + coords[2] + "," + coords[3] + "   " + coords[4] + "," + coords[5]);
          pi.next();
     }The output was this:
Move To: 71.96699141100893,71.96699141100893   0.0,0.0   0.0,0.0
Cubic To: 101.25631329235418,42.6776695296637   148.74368670764582,42.6776695296637   178.03300858899107,71.96699141100893
Cubic To: 207.32233047033628,101.25631329235418   207.32233047033628,148.74368670764582   178.03300858899107,178.03300858899107
Cubic To: 148.74368670764582,207.32233047033628   101.25631329235418,207.32233047033628   71.96699141100893,178.03300858899107Clearly this isn't what I'm looking for. Does anyone have any suggestions on how I might go about doing this?
Any input is appreciated.

Answer 1

import java.awt.*;
import java.awt.geom.*;
import java.util.List;
import java.util.*;
import javax.swing.*;
public class TraversePoints extends JPanel {
    Arc2D.Double arc = new Arc2D.Double(50,50,150,150,135,-270,Arc2D.OPEN);
    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(arc);
        g2.setPaint(Color.red);
        AffineTransform at = AffineTransform.getTranslateInstance(150, 100);
        Point2D.Double[] points = getTraversalPoints(at, 1.0);
        for(int j = 0; j < points.length; j++)
            g2.fill(new Ellipse2D.Double(points[j].x-2, points[j].y-2, 4, 4));
    private Point2D.Double[] getTraversalPoints(AffineTransform at,
                                                double flatness) {
        List<Point2D.Double> list = new ArrayList<Point2D.Double>();
        PathIterator pit = arc.getPathIterator(at, flatness);
        double[] coords = new double[6];
        int count = 0;
        while(!pit.isDone()) {
            int type = pit.currentSegment(coords);
            switch(type) {
                case PathIterator.SEG_MOVETO:
                    // fall through
                case PathIterator.SEG_LINETO:
                    list.add(new Point2D.Double(coords[0], coords[1]));
                    break;
                case PathIterator.SEG_CLOSE:
                    System.out.println("CLOSE");
                    break;
                default:
                    System.out.println("unexpected type = : " + type);
            count++;
            pit.next();
        System.out.printf("%d points at flatness = %.1f%n",
                           count, flatness);
        return list.toArray(new Point2D.Double[list.size()]);
    public static void main(String[] args) {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new TraversePoints());
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
}