From 1be717f362353e558a260329545cebcb8efddcc1 Mon Sep 17 00:00:00 2001
From: Andrzej Kapolka <andrzej@threerings.net>
Date: Thu, 12 Aug 2010 20:54:12 +0000
Subject: [PATCH] Notify sounds (via their groups) when the base gain changes.

git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@980 ed5b42cb-e716-0410-a449-f6a68f950b19
---
 src/java/com/threerings/openal/Sound.java     | 16 +++++++---
 .../com/threerings/openal/SoundGroup.java     | 20 +++++++++++++
 .../com/threerings/openal/SoundManager.java   | 29 +++++++++++++++++++
 3 files changed, 61 insertions(+), 4 deletions(-)

diff --git a/src/java/com/threerings/openal/Sound.java b/src/java/com/threerings/openal/Sound.java
index 4a811ae2..a6126eaa 100644
--- a/src/java/com/threerings/openal/Sound.java
+++ b/src/java/com/threerings/openal/Sound.java
@@ -89,10 +89,8 @@ public class Sound
      */
     public void setGain (float gain)
     {
-        if (_source != null) {
-            _source.setGain(gain * _group.getBaseGain());
-        }
         _gain = gain;
+        updateSourceGain();
     }
 
     /**
@@ -366,7 +364,7 @@ public class Sound
             // configure the source with our ephemera
             _source.setPosition(_px, _py, _pz);
             _source.setVelocity(_vx, _vy, _vz);
-            _source.setGain(_gain * _group.getBaseGain());
+            updateSourceGain();
             _source.setSourceRelative(_sourceRelative);
             _source.setMinGain(_minGain);
             _source.setMaxGain(_maxGain);
@@ -389,6 +387,16 @@ public class Sound
         return true;
     }
 
+    /**
+     * Updates the source gain according to our configured gain and the base gain.
+     */
+    protected void updateSourceGain ()
+    {
+        if (_source != null) {
+            _source.setGain(_gain * _group.getBaseGain());
+        }
+    }
+
     /**
      * Called by the {@link SoundGroup} when it wants to reclaim our source.
      *
diff --git a/src/java/com/threerings/openal/SoundGroup.java b/src/java/com/threerings/openal/SoundGroup.java
index 944d1010..9dd65e36 100644
--- a/src/java/com/threerings/openal/SoundGroup.java
+++ b/src/java/com/threerings/openal/SoundGroup.java
@@ -69,6 +69,9 @@ public class SoundGroup
             pooled.source.delete();
         }
         _sources.clear();
+
+        // remove from the manager
+        _manager.removeGroup(this);
     }
 
     /**
@@ -91,6 +94,9 @@ public class SoundGroup
         _manager = manager;
         _provider = provider;
 
+        // register with the manager
+        _manager.addGroup(this);
+
         // if we were unable to initialize the sound system at all, just
         // stop here and we'll behave as if we have no available sources
         if (!_manager.isInitialized()) {
@@ -139,6 +145,20 @@ public class SoundGroup
         return _manager.getBaseGain();
     }
 
+    /**
+     * Called by the manager when the base gain has changed.
+     */
+    protected void baseGainChanged (float gain)
+    {
+        // notify any sound currently holding a source
+        for (int ii = 0, nn = _sources.size(); ii < nn; ii++) {
+            Sound holder = _sources.get(ii).holder;
+            if (holder != null) {
+                holder.updateSourceGain();
+            }
+        }
+    }
+
     /** Used to track which sources are in use. */
     protected static class PooledSource
     {
diff --git a/src/java/com/threerings/openal/SoundManager.java b/src/java/com/threerings/openal/SoundManager.java
index 58c0c164..40e99ca5 100644
--- a/src/java/com/threerings/openal/SoundManager.java
+++ b/src/java/com/threerings/openal/SoundManager.java
@@ -23,6 +23,7 @@ package com.threerings.openal;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 
 import java.nio.IntBuffer;
 
@@ -114,7 +115,15 @@ public class SoundManager
      */
     public void setBaseGain (float gain)
     {
+        if (_baseGain == gain) {
+            return;
+        }
         _baseGain = gain;
+
+        // alert the groups
+        for (int ii = 0, nn = _groups.size(); ii < nn; ii++) {
+            _groups.get(ii).baseGainChanged(gain);
+        }
     }
 
     /**
@@ -316,6 +325,23 @@ public class SoundManager
         _streams.remove(stream);
     }
 
+    /**
+     * Adds a group to the list maintained by the manager.  Called by groups when they are created.
+     */
+    protected void addGroup (SoundGroup group)
+    {
+        _groups.add(group);
+    }
+
+    /**
+     * Removes a group from the list maintained by the manager.  Called by groups when they are
+     * disposed.
+     */
+    protected void removeGroup (SoundGroup group)
+    {
+        _groups.remove(group);
+    }
+
     /**
      * Called when a source has been finalized.
      */
@@ -406,6 +432,9 @@ public class SoundManager
     /** The list of active streams. */
     protected ArrayList<Stream> _streams = Lists.newArrayList();
 
+    /** The list of active groups. */
+    protected List<SoundGroup> _groups = Lists.newArrayList();
+
     /** The list of sources to be deleted. */
     protected int[] _finalizedSources;