com.jme3.audio.Listener: format code + javadoc

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2012 jMonkeyEngine
+ * Copyright (c) 2009-2025 jMonkeyEngine
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,6 +34,11 @@ package com.jme3.audio;
 import com.jme3.math.Quaternion;
 import com.jme3.math.Vector3f;
 
+/**
+ * Represents the audio listener in the 3D sound scene.
+ * The listener defines the point of view from which sound is heard,
+ * influencing spatial audio effects like panning and Doppler shift.
+ */
 public class Listener {
 
     private final Vector3f location;
@@ -42,72 +47,161 @@ public class Listener {
     private float volume = 1;
     private AudioRenderer renderer;
 
+    /**
+     * Constructs a new {@code Listener} with default parameters.
+     */
     public Listener() {
         location = new Vector3f();
         velocity = new Vector3f();
         rotation = new Quaternion();
     }
 
+    /**
+     * Constructs a new {@code Listener} by copying the properties of another {@code Listener}.
+     *
+     * @param source The {@code Listener} to copy the properties from.
+     */
     public Listener(Listener source) {
-        location = source.location.clone();
-        velocity = source.velocity.clone();
-        rotation = source.rotation.clone();
-        volume = source.volume;
+        this.location = source.location.clone();
+        this.velocity = source.velocity.clone();
+        this.rotation = source.rotation.clone();
+        this.volume = source.volume;
+        this.renderer = source.renderer; // Note: Renderer is also copied
     }
 
+    /**
+     * Sets the {@link AudioRenderer} associated with this listener.
+     * The renderer is responsible for applying the listener's parameters
+     * to the audio output.
+     *
+     * @param renderer The {@link AudioRenderer} to associate with.
+     */
     public void setRenderer(AudioRenderer renderer) {
         this.renderer = renderer;
     }
 
+    /**
+     * Gets the current volume of the listener.
+     *
+     * @return The current volume.
+     */
     public float getVolume() {
         return volume;
     }
 
+    /**
+     * Sets the volume of the listener.
+     * If an {@link AudioRenderer} is set, it will be notified of the volume change.
+     *
+     * @param volume The new volume.
+     */
     public void setVolume(float volume) {
         this.volume = volume;
-        if (renderer != null)
-            renderer.updateListenerParam(this, ListenerParam.Volume);
+        updateListenerParam(ListenerParam.Volume);
     }
 
+    /**
+     * Gets the current location of the listener in world space.
+     *
+     * @return The listener's location as a {@link Vector3f}.
+     */
     public Vector3f getLocation() {
         return location;
     }
 
+    /**
+     * Gets the current rotation of the listener in world space.
+     *
+     * @return The listener's rotation as a {@link Quaternion}.
+     */
     public Quaternion getRotation() {
         return rotation;
     }
 
+    /**
+     * Gets the current velocity of the listener.
+     * This is used for Doppler effect calculations.
+     *
+     * @return The listener's velocity as a {@link Vector3f}.
+     */
     public Vector3f getVelocity() {
         return 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);
     }
 
+    /**
+     * Gets the up direction vector of the listener.
+     * This vector is derived from the listener's rotation.
+     *
+     * @return The listener's up direction as a {@link Vector3f}.
+     */
     public Vector3f getUp() {
         return rotation.getRotationColumn(1);
     }
 
+    /**
+     * Gets the forward direction vector of the listener.
+     * This vector is derived from the listener's rotation.
+     *
+     * @return The listener's forward direction.
+     */
     public Vector3f getDirection() {
         return rotation.getRotationColumn(2);
     }
 
+    /**
+     * Sets the location of the listener in world space.
+     * If an {@link AudioRenderer} is set, it will be notified of the position change.
+     *
+     * @param location The new location of the listener.
+     */
     public void setLocation(Vector3f location) {
         this.location.set(location);
-        if (renderer != null)
-            renderer.updateListenerParam(this, ListenerParam.Position);
+        updateListenerParam(ListenerParam.Position);
     }
 
+    /**
+     * Sets the rotation of the listener.
+     * This defines the listener's orientation in world space.
+     * If an {@link AudioRenderer} is set, it will be notified of the rotation change.
+     *
+     * @param rotation The new rotation of the listener.
+     */
     public void setRotation(Quaternion rotation) {
         this.rotation.set(rotation);
-        if (renderer != null)
-            renderer.updateListenerParam(this, ListenerParam.Rotation);
+        updateListenerParam(ListenerParam.Rotation);
     }
 
+    /**
+     * Sets the velocity of the listener.
+     * This is used for Doppler effect calculations.
+     * If an {@link AudioRenderer} is set, it will be notified of the velocity change.
+     *
+     * @param velocity The new velocity of the listener.
+     */
     public void setVelocity(Vector3f velocity) {
         this.velocity.set(velocity);
-        if (renderer != null)
-            renderer.updateListenerParam(this, ListenerParam.Velocity);
+        updateListenerParam(ListenerParam.Velocity);
+    }
+
+    /**
+     * Updates the associated {@link AudioRenderer} with the specified listener parameter.
+     * This method checks if a renderer is set before attempting to update it.
+     *
+     * @param param The {@link ListenerParam} to update on the renderer.
+     */
+    private void updateListenerParam(ListenerParam param) {
+        if (renderer != null) {
+            renderer.updateListenerParam(this, param);
+        }
     }
 }