Allow a custom root node to be created.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4071 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/jme/JmeApp.java

@@ -384,12 +384,22 @@ public class JmeApp
         _iface = new Node("Interface");
         _root.attachChild(_iface);
 
-        _rnode = new PolledRootNode(_timer, _input);
+        // create our root node
+        _rnode = createRootNode();
         _iface.attachChild(_rnode);
+
         // we don't hide the cursor
         MouseInput.get().setCursorVisible(true);
     }
 
+    /**
+     * Allows a customized root node to be created.
+     */
+    protected BRootNode createRootNode ()
+    {
+        return new PolledRootNode(_timer, _input);
+    }
+
     /**
      * Called when initialization fails to give the application a chance
      * to report the failure to the user.