Reduce object allocations in AudioListener (#2501)

* Update Listener.java

* preserve backward compatibility

* reduce allocations in ALAudioRenderer

* Refactor getLeft, getUp, and getDirection methods

---------

Co-authored-by: Riccardo Balbo <os@rblb.it>

Author: capdevon

jme3-core/src/main/java/com/jme3/audio/Listener.java

@@ -41,19 +41,17 @@
  */
 public class Listener {
 
-    private final Vector3f location;
-    private final Vector3f velocity;
-    private final Quaternion rotation;
-    private float volume = 1;
+    private final Vector3f location = new Vector3f();
+    private final Vector3f velocity = new Vector3f();
+    private final Quaternion rotation = new Quaternion();
+    private float volume = 1f;
     private AudioRenderer renderer;
 
+
     /**
      * Constructs a new {@code Listener} with default parameters.
      */
     public Listener() {
-        location = new Vector3f();
-        velocity = new Vector3f();
-        rotation = new Quaternion();
     }
 
     /**
@@ -62,9 +60,9 @@ public Listener() {
      * @param source The {@code Listener} to copy the properties from.
      */
     public Listener(Listener source) {
-        this.location = source.location.clone();
-        this.velocity = source.velocity.clone();
-        this.rotation = source.rotation.clone();
+        this.location.set(source.location);
+        this.velocity.set(source.velocity);
+        this.rotation.set(source.rotation);
         this.volume = source.volume;
         this.renderer = source.renderer; // Note: Renderer is also copied
     }
@@ -109,6 +107,17 @@ public Vector3f getLocation() {
         return location;
     }
 
+    /**
+     * Gets the current location of the listener in world space.
+     * 
+     * @param store The vector to store the result in.
+     * @return The listener's location as a {@link Vector3f}.
+     */
+    public Vector3f getLocation(Vector3f store) {
+        if (store == null) store = new Vector3f();
+        return store.set(location);
+    }
+
     /**
      * Gets the current rotation of the listener in world space.
      *
@@ -118,6 +127,17 @@ public Quaternion getRotation() {
         return rotation;
     }
 
+    /**
+     * Gets the current rotation of the listener in world space.
+     * 
+     * @param store The quaternion to store the result in.
+     * @return The listener's rotation as a {@link Quaternion}.
+     */
+    public Quaternion getRotation(Quaternion store) {
+        if (store == null) store = new Quaternion();
+        return store.set(rotation);
+    }
+
     /**
      * Gets the current velocity of the listener.
      * This is used for Doppler effect calculations.
@@ -128,14 +148,35 @@ public Vector3f getVelocity() {
         return velocity;
     }
 
+    /**
+     * Gets the current velocity of the listener.
+     * 
+     * @param store The vector to store the result in.
+     * @return The listener's velocity as a {@link Vector3f}.
+     */
+    public Vector3f getVelocity(Vector3f store) {
+        if (store == null) store = new Vector3f();
+        return store.set(velocity);
+    }
+
     /**
      * Gets the left direction vector of the listener.
      * This vector is derived from the listener's rotation.
      *
      * @return The listener's left direction as a {@link Vector3f}.
      */
     public Vector3f getLeft() {
-        return rotation.getRotationColumn(0);
+        return getLeft(null);
+    }
+
+    /**
+     * Gets the left direction vector of the listener. This vector is derived from the listener's rotation.
+     *
+     * @param store The vector to store the result in.
+     * @return The listener's left direction as a {@link Vector3f}.
+     */
+    public Vector3f getLeft(Vector3f store) {
+        return rotation.getRotationColumn(0, store);
     }
 
     /**
@@ -145,7 +186,18 @@ public Vector3f getLeft() {
      * @return The listener's up direction as a {@link Vector3f}.
      */
     public Vector3f getUp() {
-        return rotation.getRotationColumn(1);
+        return getUp(null);
+    }
+
+    /**
+     * Gets the up direction vector of the listener. 
+     * This vector is derived from the listener's rotation.
+     *
+     * @param store The vector to store the result in.
+     * @return The listener's up direction as a {@link Vector3f}.
+     */
+    public Vector3f getUp(Vector3f store) {
+        return rotation.getRotationColumn(1, store);
     }
 
     /**
@@ -155,7 +207,18 @@ public Vector3f getUp() {
      * @return The listener's forward direction.
      */
     public Vector3f getDirection() {
-        return rotation.getRotationColumn(2);
+        return getDirection(null);
+    }
+
+    /**
+     * Gets the forward direction vector of the listener. 
+     * This vector is derived from the listener's rotation.
+     *
+     * @param store The vector to store the result in.
+     * @return The listener's forward direction.
+     */
+    public Vector3f getDirection(Vector3f store) {
+        return rotation.getRotationColumn(2, store);
     }
 
     /**

jme3-core/src/main/java/com/jme3/audio/openal/ALAudioRenderer.java

@@ -50,6 +50,8 @@
 import com.jme3.math.Vector3f;
 import com.jme3.util.BufferUtils;
 import com.jme3.util.NativeObjectManager;
+import com.jme3.util.TempVars;
+
 import java.nio.ByteBuffer;
 import java.nio.FloatBuffer;
 import java.nio.IntBuffer;
@@ -766,14 +768,16 @@ private void applyListenerPosition(Listener listener) {
     }
 
     private void applyListenerRotation(Listener listener) {
-        Vector3f dir = listener.getDirection();
-        Vector3f up = listener.getUp();
+        TempVars vars = TempVars.get();
+        Vector3f dir = listener.getDirection(vars.vect1);
+        Vector3f up = listener.getUp(vars.vect2);
         // Use the shared FloatBuffer fb
         fb.rewind();
         fb.put(dir.x).put(dir.y).put(dir.z);
         fb.put(up.x).put(up.y).put(up.z);
         fb.flip();
         al.alListener(AL_ORIENTATION, fb);
+        vars.release();
     }
 
     private void applyListenerVelocity(Listener listener) {