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copied!<p>Absent a clear question, a simple animation using your coordinate arrays is shown below. In general you can transform the graphics context (<code>g2d</code>) or the polygonal <code>Shape</code> itself (<code>p3</code>); the example shows both. Resize the window to see the effect of each.</p> <p>Note the <em>last-specified-first-applied</em> order of the transformations in <code>at</code>. First, a suitable point on <code>p3</code> is translated to the origin, then <code>p3</code> is scaled, and then <code>p3</code> is translated to the center of the panel. The <code>+ 10</code> fudge factor applied to <code>p3</code> is an artifact of having no symmetric rotation point. It may be easier to define your polygons relative to the origin, as shown in this <a href="http://sites.google.com/site/drjohnbmatthews/point-in-polygon" rel="nofollow noreferrer">example</a>.</p> <p><img src="https://i.stack.imgur.com/o1Yrw.png" alt="AffineTest"></p> <pre><code>import java.awt.*; import java.awt.event.*; import java.awt.geom.AffineTransform; import javax.swing.*; /** @see http://stackoverflow.com/questions/3405799 */ public class AffineTest extends JPanel implements ActionListener { private static final double DELTA_THETA = Math.PI / 45; // 4° private static final double DELTA_SCALE = 0.1; private int[] p1x = {200, 200, 240, 240, 220, 220, 200}; private int[] p1y = {200, 260, 260, 240, 240, 200, 200}; private int[] p2x = {600, 600, 620, 620, 640, 640, 660, 660, 600}; private int[] p2y = {400, 420, 420, 460, 460, 420, 420, 400, 400}; private int[] p3x = {400, 400, 460, 460, 440, 440, 420, 420, 400}; private int[] p3y = {400, 460, 460, 400, 400, 440, 440, 400, 400}; private Polygon p1 = new Polygon(p1x, p1y, p1x.length); private Polygon p2 = new Polygon(p2x, p2y, p2x.length); private Polygon p3 = new Polygon(p3x, p3y, p3x.length); private AffineTransform at = new AffineTransform(); private double dt = DELTA_THETA; private double theta; private double ds = DELTA_SCALE; private double scale = 1; private Timer timer = new Timer(100, this); public AffineTest() { this.setPreferredSize(new Dimension(700, 700)); this.setBackground(Color.white); p1.translate(-50, +100); p2.translate(-100, -100); } @Override public void actionPerformed(ActionEvent event) { theta += dt; scale += ds; if (scale < .5 || scale > 4) { ds = -ds; } repaint(); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g; g2d.setRenderingHint( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); int w = this.getWidth(); int h = this.getHeight(); g2d.drawLine(w / 2, 0, w / 2, h); g2d.drawLine(0, h / 2, w, h / 2); g2d.rotate(theta, w / 2, h / 2); g2d.drawPolygon(p1); g2d.drawPolygon(p2); at.setToIdentity(); at.translate(w / 2, h / 2); at.scale(scale, scale); at.translate(-p3x[5] + 10, -p3y[5]); g2d.setPaint(Color.blue); g2d.fill(at.createTransformedShape(p3)); } public void start() { timer.start(); } public static void main(String[] args) { JFrame frame = new JFrame("Affine Test"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); AffineTest sl = new AffineTest(); frame.add(sl); frame.pack(); frame.setVisible(true); sl.start(); } } </code></pre>

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