diff --git a/java/2-9-HitTest/ClosestPoint.java b/java/2-9-HitTest/ClosestPoint.java
new file mode 100644
index 0000000000000000000000000000000000000000..0d1242476664ac882ccca1520bfbf35748df9c83
--- /dev/null
+++ b/java/2-9-HitTest/ClosestPoint.java
@@ -0,0 +1,153 @@
+/*
+* CS 349 Java Code Examples
+*
+* ClosestPoint Uses two methods to compute distance from
+ mouse to closest point on line. Double click
+ to generate new line.
+*
+*/
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+
+import java.awt.event.MouseMotionAdapter;
+import java.awt.event.MouseAdapter;
+
+import java.awt.*;
+import java.awt.event.MouseEvent;
+import java.awt.geom.*;
+import java.util.ArrayList;
+import javax.vecmath.*;
+import java.lang.Math.*;
+import java.util.Random;
+
+// create the window and run the demo
+public class ClosestPoint extends JPanel {
+
+ Point P0 = new Point();
+ Point P1 = null;
+ Point M = new Point(); // mouse point
+
+ public static void main(String[] args) {
+ // create the window
+ ClosestPoint canvas = new ClosestPoint();
+ JFrame f = new JFrame("ClosestPoint"); // jframe is the app window
+ f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+ f.setSize(400, 400); // window size
+ f.setContentPane(canvas); // add canvas to jframe
+ f.setVisible(true); // show the window
+ }
+
+ ClosestPoint() {
+ setBackground(Color.WHITE);
+ // add listeners
+ addMouseListener(new MouseAdapter(){
+ public void mouseClicked(MouseEvent arg0) {
+ // generate new line on double click
+ if (arg0.getClickCount() == 2)
+ randomLine();
+ repaint();
+ }
+ });
+
+ addMouseMotionListener(new MouseMotionAdapter(){
+ public void mouseMoved(MouseEvent arg0) {
+ // TODO Auto-generated method stub
+ M.x = arg0.getX();
+ M.y = arg0.getY();
+ repaint();
+ }
+ });
+ }
+
+ // custom graphics drawing
+ public void paintComponent(Graphics g) {
+ super.paintComponent(g); // JPanel paint
+ Graphics2D g2 = (Graphics2D)g;
+
+ if (P1 == null) {
+ P1 = new Point();
+ randomLine();
+ }
+
+ // antiliasing
+ g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
+ RenderingHints.VALUE_ANTIALIAS_ON);
+
+ g2.setStroke(new BasicStroke(2));
+
+ // draw line
+ g2.setColor(Color.BLACK);
+ g2.drawLine(P0.x, P0.y, P1.x, P1.y);
+
+ // draw mouse point
+ g2.setColor(Color.BLACK);
+ int s = 7;
+ g2.drawOval(M.x - s, M.y - s, 2 * s, 2 * s );
+
+ // get closest point using the vector projection method
+ Point2d M2 = new Point2d(M.x, M.y);
+ Point2d I1 = closestPoint(M2,
+ new Point2d(P0.x, P0.y),
+ new Point2d(P1.x, P1.y));
+
+ // draw closest point
+ g2.setColor(Color.RED);
+ g2.drawOval((int)I1.x - s, (int)I1.y - s, 2 * s, 2 * s );
+
+ // use that to get distance
+ double d1 = M2.distance(I1);
+
+ // get distance using Java2D method
+ double d2 = Line2D.ptSegDist(P0.x, P0.y, P1.x, P1.y, M.x, M.y);
+
+ g2.setColor(Color.BLACK);
+ g2.drawString(String.format("%.1f %.1f", d1, d2), M.x + 10,M.y);
+ }
+
+ // find closest point using projection method
+ static Point2d closestPoint(Point2d M, Point2d P0, Point2d P1) {
+ Vector2d v = new Vector2d();
+ v.sub(P1,P0); // v = P1 - P0
+
+ // early out if line is less than 1 pixel long
+ if (v.lengthSquared() < 0.5)
+ return P0;
+
+ Vector2d u = new Vector2d();
+ u.sub(M,P0); // u = M - P1
+
+ // scalar of vector projection ...
+ double s = u.dot(v) / v.dot(v);
+
+ // find point for constrained line segment
+ if (s < 0)
+ return P0;
+ else if (s > 1)
+ return P1;
+ else {
+ Point2d I = P0;
+ Vector2d w = new Vector2d();
+ w.scale(s, v); // w = s * v
+ I.add(w); // I = P0 + w
+ return I;
+ }
+ }
+
+ // random numbers
+ static Random rand = new Random();
+
+ int random(int min, int max) {
+ return rand.nextInt(max - min + 1) + min;
+ }
+
+ void randomLine()
+ {
+ // create random line
+ int m = 50; // margin
+ P0.x = m;
+ P0.y = random(m, getHeight() - m);
+ P1.x = getWidth() - m;
+ P1.y = random(m, getHeight() - m);
+ }
+
+}
diff --git a/java/2-9-HitTest/PolygonHittest.java b/java/2-9-HitTest/PolygonHittest.java
new file mode 100644
index 0000000000000000000000000000000000000000..97da3a017b3ee4e0b00656721255984d8a612def
--- /dev/null
+++ b/java/2-9-HitTest/PolygonHittest.java
@@ -0,0 +1,58 @@
+/*
+* CS 349 Java Code Examples
+*
+* PolygonHittest Uses built-in method to hit-test closed polygon.
+*
+*/
+import java.awt.*;
+import java.awt.event.*;
+import java.awt.geom.*;
+import javax.swing.*;
+
+public class PolygonHittest extends JPanel{
+
+ Point M = new Point(); // mouse point
+ Polygon poly = new Polygon();
+
+ public static void main(String args[]){
+ JFrame window = new JFrame("PolygonHittest");
+ window.setSize(300, 300);
+ window.setContentPane(new PolygonHittest());
+ window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+ window.setVisible(true);
+ }
+
+ public PolygonHittest(){
+ this.addMouseListener(new MouseAdapter(){
+ public void mouseClicked(MouseEvent e){
+ poly.addPoint(e.getX(), e.getY());
+ repaint();
+ }
+ });
+
+ this.addMouseMotionListener(new MouseAdapter(){
+ public void mouseMoved(MouseEvent e){
+ M.x = e.getX();
+ M.y = e.getY();
+ repaint();
+ }
+ });
+
+ }
+
+ public void paintComponent(Graphics g) {
+ super.paintComponent(g);
+ Graphics2D g2 = (Graphics2D) g;
+
+ if (poly.contains(M.x, M.y))
+ g2.setColor(Color.BLUE);
+ else
+ g2.setColor(Color.RED);
+
+ g2.fillPolygon(poly);
+
+ g2.setColor(Color.BLACK);
+ g.drawPolyline(poly.xpoints, poly.ypoints, poly.npoints);
+
+ }
+}
diff --git a/java/2-9-HitTest/TransformHittest.java b/java/2-9-HitTest/TransformHittest.java
new file mode 100644
index 0000000000000000000000000000000000000000..a433079f1301496d2e3eff8b10e01d88de2d0f18
--- /dev/null
+++ b/java/2-9-HitTest/TransformHittest.java
@@ -0,0 +1,130 @@
+/*
+* CS 349 Java Code Examples
+*
+* CompositionOrder Demo of different concatenation orders of matrix transforms.
+* Click the window to change the order.
+*
+*/
+import javax.swing.JFrame;
+import javax.swing.JComponent;
+import java.awt.*;
+import java.awt.geom.*;
+import java.lang.Math.*;
+import java.awt.event.*;
+
+// create the window and run the demo
+public class TransformHittest {
+
+ public static void main(String[] args) {
+ // create the window
+ Canvas canvas = new Canvas();
+ JFrame f = new JFrame("CompositionOrder"); // jframe is the app window
+ f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+ f.setSize(500, 700); // window size
+ f.setContentPane(canvas); // add canvas to jframe
+ f.setBackground(Color.WHITE);
+ f.setVisible(true); // show the window
+ }
+}
+
+class Canvas extends JComponent {
+
+ Point M = new Point(); // mouse point
+
+ AffineTransform AT1;
+ AffineTransform AT2;
+
+
+ // the house shape (model position is centred at top left corner)
+ private Polygon shape = new Polygon(new int[] { -50, 50, 50, 0, -50},
+ new int[] { 75, 75, -25, -75, -25}, 5);
+
+ // a larger font for displaying the concatenation order
+ private Font font = new Font("SansSerif", Font.PLAIN, 30);
+
+ // the concatenation order
+ private int order = 0;
+
+ Canvas() {
+
+ // create transformation matrices
+ AT1 = new AffineTransform();
+ AT1.translate(350, 100);
+ AT1.rotate(Math.toRadians(30));
+ AT1.scale(1, 1);
+
+ // create another transformation matrices
+ AT2 = new AffineTransform();
+ AT2.translate(200, 300);
+ AT2.rotate(Math.toRadians(30));
+ AT2.scale(2, 2);
+
+ this.addMouseMotionListener(new MouseAdapter(){
+ public void mouseMoved(MouseEvent e){
+ M.x = e.getX();
+ M.y = e.getY();
+ repaint();
+ }
+ });
+
+ System.out.println("click to change transformation composition order");
+ }
+
+ // custom graphics drawing
+ public void paintComponent(Graphics g) {
+ super.paintComponent(g); // JPanel paint
+ Graphics2D g2 = (Graphics2D)g;
+
+ // save the current transform matrix
+ AffineTransform ATG = g2.getTransform();
+
+ // draw the original shape in "model" coordinates
+ g2.setColor(Color.BLACK);
+ g2.setStroke(new BasicStroke(3));
+ g2.drawPolygon(shape.xpoints, shape.ypoints, shape.npoints);
+
+
+ // Transformed Shape 1
+ g2.setTransform(AT1); // Use Transform Matrix AT1 for shape1
+ g2.setColor(Color.RED);
+ g2.drawPolygon(shape.xpoints, shape.ypoints, shape.npoints);
+ // hit test
+ Point MT = new Point();
+ try{
+ AffineTransform IAT1 = AT1.createInverse();
+ IAT1.transform(M, MT);
+ if (shape.contains(MT.x, MT.y))
+ g2.setColor(Color.RED);
+ else
+ g2.setColor(Color.WHITE);
+
+ } catch (NoninvertibleTransformException e){
+ // error
+ }
+ g2.fillPolygon(shape);
+
+
+ // Transformed Shape 1
+ g2.setTransform(AT2); // Use Transform Matrix AT2 for shape2
+ g2.setColor(Color.BLUE);
+ g2.drawPolygon(shape.xpoints, shape.ypoints, shape.npoints);
+ // hit test
+ try{
+ AffineTransform IAT2 = AT2.createInverse();
+ IAT2.transform(M, MT);
+ if (shape.contains(MT.x, MT.y))
+ g2.setColor(Color.BLUE);
+ else
+ g2.setColor(Color.WHITE);
+ } catch (NoninvertibleTransformException e){
+ // error
+ }
+ g2.fillPolygon(shape);
+
+ // reset to transform
+ g2.setTransform(ATG);
+
+ }
+
+
+}
diff --git a/java/2-9-HitTest/makefile b/java/2-9-HitTest/makefile
new file mode 100644
index 0000000000000000000000000000000000000000..f5ae3b5c4501fef12a31d0df6d9a89303c022fb9
--- /dev/null
+++ b/java/2-9-HitTest/makefile
@@ -0,0 +1,25 @@
+# super simple makefile
+# call it using 'make NAME=name_of_code_file_without_extension'
+# (assumes a .java extension)
+NAME = ClosestPoint
+# you may need to pass OS=win to run on windows
+OS =
+
+# HACK: vecmath is included regardless if needed
+all:
+ @echo "Compiling..."
+ javac -cp vecmath.jar $(NAME).java
+
+run: all
+# windows needs a semicolon
+ifeq ($(OS),win)
+ @echo "Running on windows ..."
+ java -cp "vecmath.jar;." $(NAME)
+# everyone else likes a colon
+else
+ @echo "Running ..."
+ java -cp "vecmath.jar:." $(NAME)
+endif
+
+clean:
+ rm -rf *.class