added clear_sound_proc method to backend API (this requires all backends to be modified, but can't help it)

svn-id: r8409

3 files changed, 13 insertions, 0 deletions

diff --git a/backends/sdl/sdl-common.cpp b/backends/sdl/sdl-common.cpp
index 34cbdedfb3..3d3acf573e 100644
--- a/backends/sdl/sdl-common.cpp
+++ b/backends/sdl/sdl-common.cpp
@@ -847,6 +847,10 @@ bool OSystem_SDL_Common::set_sound_proc(SoundProc *proc, void *param, SoundForma
 	return true;
 }
 
+void OSystem_SDL_Common::clear_sound_proc() {
+	SDL_CloseAudio();
+}
+
 uint32 OSystem_SDL_Common::property(int param, Property *value) {
 	switch(param) {
 
diff --git a/backends/sdl/sdl-common.h b/backends/sdl/sdl-common.h
index 89d28a8087..c5e6847ffa 100644
--- a/backends/sdl/sdl-common.h
+++ b/backends/sdl/sdl-common.h
@@ -79,6 +79,8 @@ public:
 
 	// Set function that generates samples 
 	bool set_sound_proc(SoundProc *proc, void *param, SoundFormat format);
+	
+	void clear_sound_proc();
 
 	// Poll CD status
 	// Returns true if cd audio is playing
diff --git a/common/system.h b/common/system.h
index d8c06d1ef0..68408a6a13 100644
--- a/common/system.h
+++ b/common/system.h
@@ -258,6 +258,13 @@ public:
 	 * @param format	the sample type format.
 	 */
 	virtual bool set_sound_proc(SoundProc *proc, void *param, SoundFormat format) = 0;
+	
+	/**
+	 * Remove any audio callback previously set via set_sound_proc, thus effectively
+	 * stopping all audio output immediately.
+	 * @see set_sound_proc
+	 */
+	virtual void clear_sound_proc() = 0;
 	//@}