Added to various functions a check whether an OpenAL source exists on which OpenAL functions can be called.

Playback of background music starts now with the previously set volume, independent of the OpenAL source state.
Added a delete on the SimpleSoundEngine object within CocosDenshionTest::onExit() so that alutExit() gets called to release allocated resources by OpenAL.

CocosDenshion/include/SimpleAudioEngine.h

@@ -57,6 +57,8 @@ static inline unsigned int getHashCodeByString(const char *key)
 /**
   @class          SimpleAudioEngine
   @brief          Offers a VERY simple interface to play background music & sound effects.
+  @note           Make sure to call SimpleAudioEngine::end() when the sound engine is not needed anymore
+                  to release allocated resources.
  */
 
 class EXPORT_DLL SimpleAudioEngine : public TypeInfo
@@ -76,26 +78,26 @@ public:
 
     /**
     @brief Release the shared Engine object
-    @warning It must be called before the application exit, or a memroy leak will be caused.
+    @warning It must be called before the application exit, or a memory leak will be caused.
      */
     static void end();
 
     /**
      @brief Preload background music
-     @param pszFilePath The path of the background music file, or the FileName of T_SoundResInfo
+     @param pszFilePath The path of the background music file.
      */
     void preloadBackgroundMusic(const char* pszFilePath);
     
     /**
     @brief Play background music
-    @param pszFilePath The path of the background music file, or the FileName of T_SoundResInfo
+    @param pszFilePath The path of the background music file.
-    @param bLoop Determines whether the background music should loop or not
+    @param bLoop Determines whether the background music should loop or not.
      */
     void playBackgroundMusic(const char* pszFilePath, bool bLoop);
 
     /**
     @brief Play background music once
-    @param pszFilePath The path of the background music file, or the FileName of T_SoundResInfo
+    @param pszFilePath The path of the background music file.
     @see CocosDenshion::playBackgroundMusic(const char* pszFilePath, bool bLoop)
      */
     void playBackgroundMusic(const char* pszFilePath) {
@@ -134,7 +136,6 @@ public:
     /**
      @brief Indicates whether any background music can be played or not.
      @return <i>true</i> if background music can be played, otherwise <i>false</i>.
-     @remark Returns currently always true.
      */
     bool willPlayBackgroundMusic();
 
@@ -155,7 +156,7 @@ public:
 
     /**
     @brief Set the volume of background music
-    @param volume must be within the range of 0.0 as the minimum and 1.0 as the maximum
+    @param volume must be within the range of 0.0 as the minimum and 1.0 as the maximum.
     */
     void setBackgroundMusicVolume(float volume);
 
@@ -166,7 +167,7 @@ public:
 
     /**
     @brief Set the volume of sound effects
-    @param volume must be within the range of 0.0 as the minimum and 1.0 as the maximum
+    @param volume must be within the range of 0.0 as the minimum and 1.0 as the maximum.
     */
     void setEffectsVolume(float volume);
 
@@ -176,7 +177,7 @@ public:
 
     /**
     @brief Play sound effect
-    @param pszFilePath The path of the effect file, or the FileName of T_SoundResInfo
+    @param pszFilePath The path of the effect file.
     @param bLoop Determines whether to loop the effect playing or not. The default value is false.
     */
     unsigned int playEffect(const char* pszFilePath, bool bLoop) {
@@ -185,7 +186,7 @@ public:
 
     /**
     @brief Play sound effect once
-    @param pszFilePath The path of the effect file, or the FileName of T_SoundResInfo
+    @param pszFilePath The path of the effect file.
     @see CocosDenshion::playEffect(const char* pszFilePath, bool bLoop)
     */
     unsigned int playEffect(const char* pszFilePath) {
@@ -194,7 +195,7 @@ public:
 
     /**
     @brief Play sound effect with a file path, pitch, pan and gain
-    @param pszFilePath The path of the effect file, or the FileName of T_SoundResInfo
+    @param pszFilePath The path of the effect file.
     @param bLoop Determines whether to loop the effect playing or not. The default value is false.
     @param pitch Frequency, normal value is 1.0. Will also change effect play time.
     @param pan   Stereo effect, in the range of [-1..1] where -1 enables only left channel.
@@ -246,13 +247,13 @@ public:
     /**
     @brief          preload a compressed audio file
     @details        the compressed audio will be decoded to wave, then written into an internal buffer in SimpleAudioEngine
-    @param pszFilePath The path of the effect file, or the FileName of T_SoundResInfo
+    @param pszFilePath The path of the effect file
     */
     void preloadEffect(const char* pszFilePath);
 
     /**
     @brief          unload the preloaded effect from internal buffer
-    @param pszFilePath        The path of the effect file, or the FileName of T_SoundResInfo
+    @param pszFilePath        The path of the effect file
     */
     void unloadEffect(const char* pszFilePath);
 };

CocosDenshion/openal/SimpleAudioEngineOpenAL.cpp

@@ -111,7 +111,12 @@ namespace CocosDenshion
 
     static void stopBackground(bool bReleaseData)
     {
-		alSourceStop(s_backgroundSource);
+        // The background music might have been already stopped
+        // Stop request can come from 
+        //   - stopBackgroundMusic(..)
+        //   - end(..)
+        if (s_backgroundSource != AL_NONE)
+            alSourceStop(s_backgroundSource);
 
 		if (bReleaseData)
 		{
@@ -130,7 +135,7 @@ namespace CocosDenshion
 			}
 		}
 
-		s_backgroundSource = AL_NONE;
+        s_backgroundSource = AL_NONE;
     }
 
     static void setBackgroundVolume(float volume)
@@ -246,6 +251,7 @@ namespace CocosDenshion
 
 	void SimpleAudioEngine::playBackgroundMusic(const char* pszFilePath, bool bLoop)
 	{
+        // If there is already a background music source we stop it first
 		if (s_backgroundSource != AL_NONE)
 			stopBackgroundMusic(false);
 
@@ -263,6 +269,7 @@ namespace CocosDenshion
 		{
 			s_backgroundSource = it->second->source;
 			alSourcei(s_backgroundSource, AL_LOOPING, bLoop ? AL_TRUE : AL_FALSE);
+            setBackgroundVolume(s_volume);
 			alSourcePlay(s_backgroundSource);
 			checkALError("playBackgroundMusic:alSourcePlay");
 		}
@@ -270,6 +277,10 @@ namespace CocosDenshion
 
 	void SimpleAudioEngine::stopBackgroundMusic(bool bReleaseData)
 	{
+        // If there is no source, then there is nothing that can be stopped
+        if (s_backgroundSource == AL_NONE)
+            return;
+
         ALint state;
         alGetSourcei(s_backgroundSource, AL_SOURCE_STATE, &state);
         if (state == AL_PLAYING)
@@ -278,27 +289,43 @@ namespace CocosDenshion
 
 	void SimpleAudioEngine::pauseBackgroundMusic()
 	{
+        // If there is no source, then there is nothing that can be paused
+        if (s_backgroundSource == AL_NONE)
+            return;
+
 		ALint state;
 		alGetSourcei(s_backgroundSource, AL_SOURCE_STATE, &state);
 		if (state == AL_PLAYING)
 			alSourcePause(s_backgroundSource);
+
 		checkALError("pauseBackgroundMusic:alSourcePause");
 	}
 
 	void SimpleAudioEngine::resumeBackgroundMusic()
 	{
+        // If there is no source, then there is nothing that can be resumed
+        if (s_backgroundSource == AL_NONE)
+            return;
+
 		ALint state;
 		alGetSourcei(s_backgroundSource, AL_SOURCE_STATE, &state);
 		if (state == AL_PAUSED)
 			alSourcePlay(s_backgroundSource);
-		checkALError("resumeBackgroundMusic:alSourcePlay");
+		
+        checkALError("resumeBackgroundMusic:alSourcePlay");
     }
 
     void SimpleAudioEngine::rewindBackgroundMusic()
     {
+        // If there is no source, then there is nothing that can be rewinded
+        if (s_backgroundSource == AL_NONE)
+            return;
+
+        // Rewind and prevent the last state the source had
         ALint state;
         alGetSourcei(s_backgroundSource, AL_SOURCE_STATE, &state);
         alSourceRewind(s_backgroundSource);
+
         if (state == AL_PLAYING)
         {
             alSourcePlay(s_backgroundSource);
@@ -313,13 +340,23 @@ namespace CocosDenshion
 
 	bool SimpleAudioEngine::willPlayBackgroundMusic()
 	{
-		return true;
+        // We are able to play background music 
+        // if we have a valid background source
+        if (s_backgroundSource == AL_NONE)
+            return false;
+
+		return (alIsSource(s_backgroundSource) == AL_TRUE ? true : false);
 	}
 
 	bool SimpleAudioEngine::isBackgroundMusicPlaying()
 	{
+        // If there is no source, then there is nothing that is playing
+        if (s_backgroundSource == AL_NONE)
+            return false;
+
 	    ALint play_status;
 	    alGetSourcei(s_backgroundSource, AL_SOURCE_STATE, &play_status);
+        checkALError("isBackgroundMusicPlaying:alGetSourcei");
 
 		return (play_status == AL_PLAYING);
 	}
@@ -331,11 +368,17 @@ namespace CocosDenshion
 
 	void SimpleAudioEngine::setBackgroundMusicVolume(float volume)
 	{
+        
+
 		if (s_volume != volume && volume >= -0.0001 && volume <= 1.0001)
 		{
-    		s_volume = volume;
+            s_volume = volume;
 
-			setBackgroundVolume(volume);
+            // No source, no background music, no volume adjustment
+            if (s_backgroundSource != AL_NONE)
+            {
+                setBackgroundVolume(volume);
+            }
 		}
 	}
 

samples/Cpp/TestCpp/Classes/CocosDenshionTest/CocosDenshionTest.cpp

@@ -247,6 +247,7 @@ void CocosDenshionTest::onExit()
     Layer::onExit();
 
     SimpleAudioEngine::sharedEngine()->end();
+    delete SimpleAudioEngine::sharedEngine();
 }
 
 void CocosDenshionTest::addButtons()