Added volume setting to Sound

include/Sound.h

     int registeredSources();
 
     /*!
+     * \brief Remove all loaded sounds
+     */
+    void clear();
+
+    /*!
+     * \brief Set the volume
+     * \param vol new source gain
+     */
+    void setVolume(float vol);
+
+    /*!
      * \brief Move listener and repositions them
      * \param pos New position for listener
      * \param angle New orientation for listener
     int addWave(unsigned char *wav, unsigned int length, int *source, unsigned int flags);
 
     /*!
-     * \brief Remove all loaded sounds
-     */
-    void clear();
-
-    /*!
      * \brief Play sound source
      * \param source sound source to play
      */
 private:
 
     bool mInit;                        //!< Guard to ensure ausio system is active
+    float mVolume;                     //!< Listener gain
     std::vector<unsigned int> mBuffer; //!< Audio buffer id list
     std::vector<unsigned int> mSource; //!< Audio source id list
 };

src/Sound.cpp

 
 Sound::Sound() {
     mInit = false;
+    mVolume = 1.0f;
 }
 
 Sound::~Sound() {
 }
 
 int Sound::init() {
+    assert(mInit == false);
+
 #ifndef __APPLE__
     int fd;
 
     return mSource.size();
 }
 
+void Sound::clear() {
+    assert(mInit == true);
+    assert(mSource.size() == mBuffer.size());
+
+    for (size_t i = 0; i < mSource.size(); i++) {
+        alDeleteSources(1, &mSource[i]);
+        alDeleteBuffers(1, &mBuffer[i]);
+    }
+
+    mSource.clear();
+    mBuffer.clear();
+}
+
+void Sound::setVolume(float vol) {
+    assert(mInit == true);
+    assert(mSource.size() == mBuffer.size());
+
+    if ((mSource.size() > 0) && (mVolume != vol)) {
+        // Apply new volume to old sources if needed
+        for (size_t i = 0; i < mSource.size(); i++)
+            alSourcef(mSource[i], AL_GAIN, vol);
+    }
+
+    mVolume = vol;
+}
+
 void Sound::listenAt(float pos[3], float angle[3]) {
     assert(mInit == true);
     assert(mSource.size() == mBuffer.size());
         alSourcei(mSource[id], AL_LOOPING, 1);
     }
 
+    alSourcef(mSource[id], AL_GAIN, mVolume);
+
     *source = id;
 
     return 0;
         alSourcei(mSource[id], AL_LOOPING, 1);
     }
 
+    alSourcef(mSource[id], AL_GAIN, mVolume);
+
     *source = id;
 
     //! \fixme Should free alut buffer?
     return 0;
 }
 
-void Sound::clear() {
-    assert(mInit == true);
-    assert(mSource.size() == mBuffer.size());
-
-    for (size_t i = 0; i < mSource.size(); i++) {
-        alDeleteSources(1, &mSource[i]);
-        alDeleteBuffers(1, &mBuffer[i]);
-    }
-
-    mSource.clear();
-    mBuffer.clear();
-}
-
 void Sound::play(int source) {
     assert(mInit == true);
     assert(mSource.size() == mBuffer.size());