Handle failing openal init properly, add enable_sound and sound_volume settings

minetest.conf.example

@@ -107,6 +107,9 @@
 #console_color = (0,0,0)
 # In-game chat console background alpha (opaqueness, between 0 and 255)
 #console_alpha = 200
+# Sound settings
+#enable_sound = true
+#sound_volume = 0.7
 
 #
 # Server stuff

src/defaultsettings.cpp

@@ -98,6 +98,8 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("opaque_water", "false");
 	settings->setDefault("console_color", "(0,0,0)");
 	settings->setDefault("console_alpha", "200");
+	settings->setDefault("enable_sound", "true");
+	settings->setDefault("sound_volume", "0.8");
 
 	// Server stuff
 	// "map-dir" doesn't exist by default.

src/game.cpp

@@ -955,10 +955,14 @@ void the_game(
 	ISoundManager *sound = NULL;
 	bool sound_is_dummy = false;
 #if USE_SOUND
-	infostream<<"Attempting to use OpenAL audio"<<std::endl;
-	sound = createOpenALSoundManager(&soundfetcher);
-	if(!sound)
-		infostream<<"Failed to initialize OpenAL audio"<<std::endl;
+	if(g_settings->getBool("enable_sound")){
+		infostream<<"Attempting to use OpenAL audio"<<std::endl;
+		sound = createOpenALSoundManager(&soundfetcher);
+		if(!sound)
+			infostream<<"Failed to initialize OpenAL audio"<<std::endl;
+	} else {
+		infostream<<"Sound disabled."<<std::endl;
+	}
 #endif
 	if(!sound){
 		infostream<<"Using dummy audio."<<std::endl;
@@ -2082,6 +2086,7 @@ void the_game(
 				v3f(0,0,0), // velocity
 				camera.getDirection(),
 				camera.getCameraNode()->getUpVector());
+		sound->setListenerGain(g_settings->getFloat("sound_volume"));
 
 		/*
 			Update sound maker

src/sound.h

@@ -58,6 +58,7 @@ public:
 			const std::string &filedata) = 0;
 
 	virtual void updateListener(v3f pos, v3f vel, v3f at, v3f up) = 0;
+	virtual void setListenerGain(float gain) = 0;
 
 	// playSound functions return -1 on failure, otherwise a handle to the
 	// sound. If name=="", call should be ignored without error.
@@ -83,6 +84,7 @@ public:
 	virtual bool loadSoundData(const std::string &name,
 			const std::string &filedata) {return true;}
 	void updateListener(v3f pos, v3f vel, v3f at, v3f up) {}
+	void setListenerGain(float gain) {}
 	int playSound(const std::string &name, bool loop,
 			float volume) {return 0;}
 	int playSoundAt(const std::string &name, bool loop,

src/sound_openal.cpp

@@ -198,12 +198,14 @@ private:
 	std::map<int, PlayingSound*> m_sounds_playing;
 	v3f m_listener_pos;
 public:
+	bool m_is_initialized;
 	OpenALSoundManager(OnDemandSoundFetcher *fetcher):
 		m_fetcher(fetcher),
 		m_device(NULL),
 		m_context(NULL),
 		m_can_vorbis(false),
-		m_next_id(1)
+		m_next_id(1),
+		m_is_initialized(false)
 	{
 		ALCenum error = ALC_NO_ERROR;
 		
@@ -252,6 +254,8 @@ public:
 		infostream<<"Audio: Initialized: OpenAL "<<alGetString(AL_VERSION)
 				<<", using "<<alcGetString(m_device, ALC_DEVICE_SPECIFIER)
 				<<std::endl;
+
+		m_is_initialized = true;
 	}
 
 	~OpenALSoundManager()
@@ -466,6 +470,11 @@ public:
 		warn_if_error(alGetError(), "updateListener");
 	}
 	
+	void setListenerGain(float gain)
+	{
+		alListenerf(AL_GAIN, gain);
+	}
+
 	int playSound(const std::string &name, bool loop, float volume)
 	{
 		maintain();
@@ -519,6 +528,10 @@ public:
 
 ISoundManager *createOpenALSoundManager(OnDemandSoundFetcher *fetcher)
 {
-	return new OpenALSoundManager(fetcher);
+	OpenALSoundManager *m = new OpenALSoundManager(fetcher);
+	if(m->m_is_initialized)
+		return m;
+	delete m;
+	return NULL;
 };