Added Sound.clone(), implemented with OpenAL.

sound/output.h

@@ -17,6 +17,11 @@ namespace Sound {
     may be connected to a SampleSource or read directly from a file,
     and they may support 3d sounds, looping and other features
     depending on the capabilities of the backend system.
+
+    To create multiple instances of one sound, it is recommended to
+    'clone' an existing instance instead of reloading it from
+    file. Cloned sounds will often (depending on the back-end) use
+    less memory due to shared buffers.
 */
 class Sound
 {
@@ -31,14 +36,33 @@ class Sound
   virtual void pause() = 0;
 
   /// Check if the sound is still playing
-  virtual bool isPlaying() = 0;
+  virtual bool isPlaying() = 0 const;
 
   /// Set the volume. The parameter must be between 0.0 and 1.0.
   virtual void setVolume(float) = 0;
 
-  /// Set the position. May not have any effect on 2D sounds.
+  /// Set left/right pan. -1.0 is left, 0.0 is center and 1.0 is right.
+  virtual void setPan(float) = 0;
+
+  /// Set the position. May not work with all backends.
   virtual void setPos(float x, float y, float z) = 0;
 
+  /// Set loop mode
+  virtual void setRepeat(bool) = 0;
+
+  /// Set streaming mode.
+  /** This may be used by implementations to optimize for very large
+      files. If streaming mode is off (default), most implementations
+      will load the entire file into memory before starting playback.
+   */
+  virtual void setStreaming(bool) = 0;
+
+  /// Create a new instance of this sound.
+  /** Playback status is not cloned, only the sound data
+      itself. Back-ends can use this as a means of sharing data and
+      saving memory. */
+  virtual Sound* clone() const = 0;
+
   /// Virtual destructor
   virtual ~Sound() {}
 };
@@ -71,12 +95,6 @@ class SoundFactory
   */
   bool has3D;
 
-  /** @brief true if 'repeat' and 'stream' can be used simultaneously.
-      If false, repeating a streamed sound will give undefined
-      behavior.
-  */
-  bool canRepeatStream;
-
   /// true if we can load sounds directly from file (containing encoded data)
   bool canLoadFile;
 
@@ -99,7 +117,7 @@ class SoundFactory
             large files, but they are not required to.
      @return a new Sound object
   */
-  virtual Sound *load(SampleSource *input, bool stream=false) = 0;
+  virtual Sound *load(SampleSource *input) = 0;
 
   /**
      @brief Load a sound file from stream. Only valid if canLoadStream
@@ -109,7 +127,7 @@ class SoundFactory
      @param stream true if the file should be streamed
      @see load(InputSource*,bool)
   */
-  virtual Sound *load(Stream::Stream *input, bool stream=false) = 0;
+  virtual Sound *load(Stream::Stream *input) = 0;
 
   /**
      @brief Load a sound directly from file. Only valid if canLoadFile
@@ -119,7 +137,7 @@ class SoundFactory
      @param stream true if the file should be streamed
      @see load(InputSource*,bool)
   */
-  virtual Sound *load(const std::string &file, bool stream=false) = 0;
+  virtual Sound *load(const std::string &file) = 0;
 
   /// Call this every frame if needsUpdate is true
   /**

sound/outputs/openal_out.cpp

@@ -103,6 +103,28 @@ void OpenAL_Sound::setPos(float x, float y, float z)
   checkALError("setting position");
 }
 
+void OpenAL_Sound::setRepeat(bool rep)
+{
+  alSourcei(Source, AL_LOOPING, rep?AL_TRUE:AL_FALSE);
+}
+
+void OpenAL_Sound::setup()
+{
+}
+
+// Constructor used for cloned sounds
+OpenAL_Sound::OpenAL_Sound(ALuint buf, int *ref)
+  : refCnt(ref), bufferID(buf)
+{
+  // Increase the reference count
+  assert(ref != NULL);
+  *refCnt++;
+
+  // Create a source
+  alGenSources(1, &inst);
+  alSourcei(inst, AL_BUFFER, bufferID);
+}
+
 OpenAL_Sound::OpenAL_Sound(SampleSource *input)
 {
   // Get the format
@@ -120,7 +142,11 @@ OpenAL_Sound::OpenAL_Sound(SampleSource *input)
 
   // Create a source
   alGenSources(1, &inst);
-  alSourcei(inst, AL_BUFFER, buf);
+  alSourcei(inst, AL_BUFFER, bufferID);
+
+  // Create a cheap reference counter for the buffer
+  refCnt = new int;
+  *refCnt = 1;
 }
 
 OpenAL_Sound::~OpenAL_Sound()
@@ -131,6 +157,12 @@ OpenAL_Sound::~OpenAL_Sound()
   // Return sound
   alDeleteSources(1, &inst);
 
-  // Delete buffer
-  alDeleteBuffers(1, &bufferID);
+  // Decrease the reference
+  if(--(*refCnt))
+    {
+      // We're the last owner. Delete the buffer and the counter
+      // itself.
+      alDeleteBuffers(1, &bufferID);
+      delete refCnt;
+    }
 }

sound/outputs/openal_out.h

@@ -18,27 +18,26 @@ class OpenAL_Sound : public Sound
   ALuint inst;
   ALuint bufferID;
 
+  // Poor mans reference counting. Might improve this later.
+  int *refCnt;
+
  public:
   OpenAL_Sound(SampleSource *input);
+  OpenAL_Sound(ALuint buf, int *ref); // Used for cloning
   ~OpenAL_Sound();
 
-  /// Play or resume the sound
   void play();
-
-  /// Stop the sound
   void stop();
-
-  /// Pause the sound, may be resumed later
   void pause();
-
-  /// Check if the sound is still playing
-  bool isPlaying();
-
-  /// Set the volume. The parameter must be between 0.0 and 1.0.
+  bool isPlaying() const;
   void setVolume(float);
-
-  /// Set the 3D position.
   void setPos(float x, float y, float z);
+  void setRepeat(bool);
+  void setStreaming(bool) {} // Not implemented yet
+  Sound* clone() const;
+
+  /// Not implemented
+  void setPan(float) {}
 };
 
 class OpenAL_Factory : public SoundFactory
@@ -56,7 +55,6 @@ class OpenAL_Factory : public SoundFactory
     {
       needsUpdate = false;
       has3D = true;
-      canRepeatStream = false;
       canLoadFile = false;
       canLoadStream = false;
       canLoadSource = true;