/*
 * Copyright (c) 2009-2016 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 com.jme3.audio;

import com.jme3.app.Application;
import com.jme3.app.state.BaseAppState;
import com.jme3.math.Quaternion;
import com.jme3.math.Vector3f;
import com.jme3.renderer.Camera;
import com.jme3.renderer.RenderManager;

/**
 * <code>AudioListenerState</code> updates the audio listener's position,
 * orientation, and velocity from a {@link Camera}.
 *
 * @author Kirill Vainer
 */
public class AudioListenerState extends BaseAppState {

    private Listener listener;
    private Camera camera;
    private float lastTpf;

    public AudioListenerState() {
    }

    @Override
    protected void initialize(Application app) {
        this.camera = app.getCamera();
        this.listener = app.getListener();
    }

    @Override
    protected void cleanup(Application app) {
    }

    @Override
    public void update(float tpf) {
        lastTpf = tpf;
    }

    @Override
    public void render(RenderManager rm) {
        if (!isEnabled()) {
            return;
        }

        Vector3f lastLocation = listener.getLocation();
        Vector3f currentLocation = camera.getLocation();
        Vector3f velocity = listener.getVelocity();

        if (!lastLocation.equals(currentLocation)) {
            velocity.set(currentLocation).subtractLocal(lastLocation);
            velocity.multLocal(1f / lastTpf);
            listener.setLocation(currentLocation);
            listener.setVelocity(velocity);
        } else if (!velocity.equals(Vector3f.ZERO)) {
            listener.setVelocity(Vector3f.ZERO);
        }

        Quaternion lastRotation = listener.getRotation();
        Quaternion currentRotation = camera.getRotation();
        if (!lastRotation.equals(currentRotation)) {
            listener.setRotation(currentRotation);
        }
    }

    @Override
    protected void onEnable() {
    }

    @Override
    protected void onDisable() {
    }
}

@@ -2532,16 +2532,36 @@
 nabled()
+ %7C%7C listener == null
 ) %7B%0A    

Fix issue #479