Add test to trigger the inconsistent compare function detection in the sorting algorithm.

It modifies a texture on a material from another thread, which changes the material's sort ID,
thus causing the OpaqueComparator's compare method to violate the compare method contract.

jme3-examples/src/main/java/jme3test/renderer/TestInconsistentCompareDetection.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2009-2014 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package jme3test.renderer;
+
+import com.jme3.app.SimpleApplication;
+import com.jme3.material.Material;
+import com.jme3.math.ColorRGBA;
+import com.jme3.math.FastMath;
+import com.jme3.math.Quaternion;
+import com.jme3.math.Vector3f;
+import com.jme3.scene.Geometry;
+import com.jme3.scene.Node;
+import com.jme3.scene.Spatial;
+import com.jme3.scene.shape.Box;
+import com.jme3.texture.Texture;
+
+/**
+ * Changes a material's texture from another thread while it is rendered.
+ * This should trigger the sorting function's inconsistent compare detection.
+ * 
+ * @author Kirill Vainer
+ */
+public class TestInconsistentCompareDetection extends SimpleApplication {
+
+    private static Texture t1, t2;
+    
+    public static void main(String[] args){
+        TestInconsistentCompareDetection app = new TestInconsistentCompareDetection();
+        app.start();
+    }
+    
+    @Override
+    public void simpleInitApp() {
+        cam.setLocation(new Vector3f(-11.441693f, 6.7038045f, 28.274843f));
+        cam.setRotation(new Quaternion(0.059138592f, 0.9084308f, -0.13765986f, 0.3902638f));
+        
+        Material m = new Material(assetManager, "Common/MatDefs/Misc/ColoredTextured.j3md");
+        m.setColor("Color", ColorRGBA.White);
+        
+        t1 = assetManager.loadTexture("Textures/Terrain/BrickWall/BrickWall.jpg");
+        t2 = assetManager.loadTexture("Textures/Terrain/Pond/Pond.jpg");
+        
+        Box b = new Box(1, 1, 1);
+
+        for (int x = 0; x < 10; x++) {
+            for (int y = 0; y < 10; y++) {
+                Geometry g = new Geometry("g_" + x + "_" + y, b);
+                Node monkey = new Node("n_" + x + "_" + y);
+                monkey.attachChild(g);
+                monkey.move(x * 2, 0, y * 2);
+
+                Material newMat = m.clone();
+                g.setMaterial(newMat);
+
+                if (FastMath.rand.nextBoolean()) {
+                    newMat.setTexture("ColorMap", t1);
+                } else {
+                    newMat.setTexture("ColorMap", t2);
+                }
+
+                rootNode.attachChild(monkey);
+            }
+        }
+        
+        Thread evilThread = new Thread(new Runnable() {
+            public void run() {
+                try {
+                    Thread.sleep(1000);
+                } catch (InterruptedException ex) {
+                }
+                
+                // begin randomly changing textures after 1 sec.
+                while (true) {
+                    for (Spatial child : rootNode.getChildren()) {
+                        Geometry g = (Geometry) (((Node)child).getChild(0));
+                        Material m = g.getMaterial();
+                        Texture curTex = m.getTextureParam("ColorMap").getTextureValue();
+                        if (curTex == t1) {
+                            m.setTexture("ColorMap", t2);
+                        } else {
+                            m.setTexture("ColorMap", t1);
+                        }
+                    }
+                }
+            }
+        });
+        evilThread.setDaemon(true);
+        evilThread.start();
+    }
+}
+