add methods to Audio class to mute/unmute and change volume per channel

src/audio.cpp

@@ -43,5 +43,32 @@ void Audio::Setup(int channels)
 #endif
 }
 
+void Audio::SetVolume(int channel, int volume)
+{
+#if defined USE_SDL_MIXER
+    Mix_Volume(channel,volume);
+#else
+    UNUSED(channel);
+#endif
+}
+
+void Audio::MuteAll()
+{
+#if defined USE_SDL_MIXER
+    Mix_Volume(-1,0);
+#else
+    UNUSED(false);
+#endif
+}
+
+void Audio::UnmuteAll()
+{
+#if defined USE_SDL_MIXER
+    Mix_Volume(-1,MIX_MAX_VOLUME);
+#else
+    UNUSED(false);
+#endif
+}
+
 } /* namespace lol */
 

src/audio.h

@@ -26,6 +26,9 @@ class Audio
 {
 public:
     static void Setup(int channels);
+    static void SetVolume(int channel,int volume);
+    static void MuteAll();
+    static void UnmuteAll();
 
 private:
     Audio() {}