Patch for http://www.cs.cornell.edu/home/chew/Delaunay.html that adds a background image.

backgroundimage.patch

This patch displays the background.png image as background of the drawing area

If no image can be loaded, the previous behavior is kept.

diff -Npru delaunay 2/DelaunayAp.java delaunay/DelaunayAp.java
--- delaunay 2/DelaunayAp.java	2007-12-14 14:51:28.000000000 +0100
+++ delaunay/DelaunayAp.java	2015-02-14 16:03:21.000000000 +0100
@@ -22,6 +22,7 @@ package delaunay;
 
 import java.awt.*;
 import java.awt.event.*;
+import java.io.*;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -29,6 +30,7 @@ import java.util.Map;
 import java.util.Random;
 
 import javax.swing.*;
+import javax.imageio.ImageIO;
 
 /**
  * The Delauany applet.
@@ -339,13 +341,21 @@ class DelaunayPanel extends JPanel {
         super.paintComponent(g);
         this.g = g;
 
-        // Flood the drawing area with a "background" color
-        Color temp = g.getColor();
-        if (!controller.isVoronoi()) g.setColor(delaunayColor);
-        else if (dt.contains(initialTriangle)) g.setColor(this.getBackground());
-        else g.setColor(voronoiColor);
-        g.fillRect(0, 0, this.getWidth(), this.getHeight());
-        g.setColor(temp);
+
+        try
+        {
+            // Draw a background image
+            Image bgImage = ImageIO.read(new File("delaunay/background.png"));
+            g.drawImage(bgImage, 0, 0, null);
+        } catch (IOException e) {
+            // Flood the drawing area with a "background" color
+            Color bgColor = g.getColor();
+            if (!controller.isVoronoi()) g.setColor(delaunayColor);
+            else if (dt.contains(initialTriangle)) g.setColor(this.getBackground());
+            else g.setColor(voronoiColor);
+            g.fillRect(0, 0, this.getWidth(), this.getHeight());
+            g.setColor(bgColor);
+        }
 
         // If no colors then we can clear the color table
         if (!controller.isColorful()) colorTable.clear();
@@ -356,7 +366,7 @@ class DelaunayPanel extends JPanel {
         else drawAllDelaunay(controller.isColorful());
 
         // Draw any extra info due to the mouse-entry switches
-        temp = g.getColor();
+        Color temp = g.getColor();
         g.setColor(Color.white);
         if (controller.showingCircles()) drawAllCircles();
         if (controller.showingDelaunay()) drawAllDelaunay(false);