Sound API: Add fading sounds

doc/lua_api.txt

@@ -456,11 +456,13 @@ Examples of sound parameter tables:
     -- Play locationless on all clients
     {
         gain = 1.0, -- default
+        fade = 0.0, -- default, change to a value > 0 to fade the sound in
     }
     -- Play locationless to one player
     {
         to_player = name,
         gain = 1.0, -- default
+        fade = 0.0, -- default, change to a value > 0 to fade the sound in
     }
     -- Play locationless to one player, looped
     {
@@ -2587,6 +2589,11 @@ These functions return the leftover itemstack.
     * `spec` is a `SimpleSoundSpec`
     * `parameters` is a sound parameter table
 * `minetest.sound_stop(handle)`
+* `minetest.sound_fade(handle, step, gain)`
+    * `handle` is a handle returned by minetest.sound_play
+    * `step` determines how fast a sound will fade.
+      Negative step will lower the sound volume, positive step will increase the sound volume
+    * `gain` the target gain for the fade.
 
 ### Timing
 * `minetest.after(time, func, ...)`

src/client.cpp

@@ -407,6 +407,7 @@ void Client::step(float dtime)
 
 	// Step environment
 	m_env.step(dtime);
+	m_sound->step(dtime);
 
 	/*
 		Get events

src/client.h

@@ -328,6 +328,7 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 	void handleCommand_ItemDef(NetworkPacket* pkt);
 	void handleCommand_PlaySound(NetworkPacket* pkt);
 	void handleCommand_StopSound(NetworkPacket* pkt);
+	void handleCommand_FadeSound(NetworkPacket *pkt);
 	void handleCommand_Privileges(NetworkPacket* pkt);
 	void handleCommand_InventoryFormSpec(NetworkPacket* pkt);
 	void handleCommand_DetachedInventory(NetworkPacket* pkt);

src/network/clientopcodes.cpp

@@ -109,7 +109,7 @@ const ToClientCommandHandler toClientCommandTable[TOCLIENT_NUM_MSG_TYPES] =
 	{ "TOCLIENT_EYE_OFFSET",               TOCLIENT_STATE_CONNECTED, &Client::handleCommand_EyeOffset }, // 0x52
 	{ "TOCLIENT_DELETE_PARTICLESPAWNER",   TOCLIENT_STATE_CONNECTED, &Client::handleCommand_DeleteParticleSpawner }, // 0x53
 	{ "TOCLIENT_CLOUD_PARAMS",             TOCLIENT_STATE_CONNECTED, &Client::handleCommand_CloudParams }, // 0x54
-	null_command_handler,
+	{ "TOCLIENT_FADE_SOUND",               TOCLIENT_STATE_CONNECTED, &Client::handleCommand_FadeSound }, // 0x55
 	null_command_handler,
 	null_command_handler,
 	null_command_handler,

src/network/clientpackethandler.cpp

@@ -755,21 +755,39 @@ void Client::handleCommand_ItemDef(NetworkPacket* pkt)
 
 void Client::handleCommand_PlaySound(NetworkPacket* pkt)
 {
+	/*
+		[0] u32 server_id
+		[4] u16 name length
+		[6] char name[len]
+		[ 6 + len] f32 gain
+		[10 + len] u8 type
+		[11 + len] (f32 * 3) pos
+		[23 + len] u16 object_id
+		[25 + len] bool loop
+		[26 + len] f32 fade
+	*/
+
 	s32 server_id;
 	std::string name;
+
 	float gain;
 	u8 type; // 0=local, 1=positional, 2=object
 	v3f pos;
 	u16 object_id;
 	bool loop;
+	float fade = 0;
 
 	*pkt >> server_id >> name >> gain >> type >> pos >> object_id >> loop;
 
+	try {
+		*pkt >> fade;
+	} catch (SerializationError &e) {};
+
 	// Start playing
 	int client_id = -1;
 	switch(type) {
 		case 0: // local
-			client_id = m_sound->playSound(name, loop, gain);
+			client_id = m_sound->playSound(name, loop, gain, fade);
 			break;
 		case 1: // positional
 			client_id = m_sound->playSoundAt(name, loop, gain, pos);
@@ -808,6 +826,21 @@ void Client::handleCommand_StopSound(NetworkPacket* pkt)
 	}
 }
 
+void Client::handleCommand_FadeSound(NetworkPacket *pkt)
+{
+	s32 sound_id;
+	float step;
+	float gain;
+
+	*pkt >> sound_id >> step >> gain;
+
+	UNORDERED_MAP<s32, int>::iterator i =
+			m_sounds_server_to_client.find(sound_id);
+
+	if (i != m_sounds_server_to_client.end())
+		m_sound->fadeSound(i->second, step, gain);
+}
+
 void Client::handleCommand_Privileges(NetworkPacket* pkt)
 {
 	m_privileges.clear();

src/network/networkprotocol.h

@@ -153,9 +153,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	PROTOCOL VERSION 31:
 		Add tile overlay
 		Stop sending TOSERVER_CLIENT_READY
+	PROTOCOL VERSION 32:
+		Add fading sounds
 */
 
-#define LATEST_PROTOCOL_VERSION 31
+#define LATEST_PROTOCOL_VERSION 32
 
 // Server's supported network protocol range
 #define SERVER_PROTOCOL_VERSION_MIN 24
@@ -620,6 +622,13 @@ enum ToClientCommand
 		v2f1000 speed
 	*/
 
+	TOCLIENT_FADE_SOUND = 0x55,
+	/*
+		s32 sound_id
+		float step
+		float gain
+	*/
+
 	TOCLIENT_SRP_BYTES_S_B = 0x60,
 	/*
 		Belonging to AUTH_MECHANISM_LEGACY_PASSWORD and AUTH_MECHANISM_SRP.

src/script/common/c_content.cpp

@@ -680,6 +680,7 @@ void read_server_sound_params(lua_State *L, int index,
 	if(lua_istable(L, index)){
 		getfloatfield(L, index, "gain", params.gain);
 		getstringfield(L, index, "to_player", params.to_player);
+		getfloatfield(L, index, "fade", params.fade);
 		lua_getfield(L, index, "pos");
 		if(!lua_isnil(L, -1)){
 			v3f p = read_v3f(L, -1)*BS;
@@ -712,6 +713,7 @@ void read_soundspec(lua_State *L, int index, SimpleSoundSpec &spec)
 	} else if(lua_istable(L, index)){
 		getstringfield(L, index, "name", spec.name);
 		getfloatfield(L, index, "gain", spec.gain);
+		getfloatfield(L, index, "fade", spec.fade);
 	} else if(lua_isstring(L, index)){
 		spec.name = lua_tostring(L, index);
 	}

src/script/common/c_converter.h

@@ -77,6 +77,8 @@ void               setfloatfield(lua_State *L, int table,
                              const char *fieldname, float value);
 void               setboolfield(lua_State *L, int table,
                              const char *fieldname, bool value);
+void               setstringfield(lua_State *L, int table,
+                             const char *fieldname, const char *value);
 
 v3f                 checkFloatPos       (lua_State *L, int index);
 v2f                 check_v2f           (lua_State *L, int index);

src/script/lua_api/l_server.cpp

@@ -455,6 +455,16 @@ int ModApiServer::l_sound_stop(lua_State *L)
 	return 0;
 }
 
+int ModApiServer::l_sound_fade(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	s32 handle = luaL_checkinteger(L, 1);
+	float step = luaL_checknumber(L, 2);
+	float gain = luaL_checknumber(L, 3);
+	getServer(L)->fadeSound(handle, step, gain);
+	return 0;
+}
+
 // is_singleplayer()
 int ModApiServer::l_is_singleplayer(lua_State *L)
 {
@@ -518,6 +528,7 @@ void ModApiServer::Initialize(lua_State *L, int top)
 	API_FCT(show_formspec);
 	API_FCT(sound_play);
 	API_FCT(sound_stop);
+	API_FCT(sound_fade);
 
 	API_FCT(get_player_information);
 	API_FCT(get_player_privs);

src/script/lua_api/l_server.h

@@ -68,6 +68,9 @@ class ModApiServer : public ModApiBase
 	// sound_stop(handle)
 	static int l_sound_stop(lua_State *L);
 
+	// sound_fade(handle, step, gain)
+	static int l_sound_fade(lua_State *L);
+
 	// get_player_privs(name, text)
 	static int l_get_player_privs(lua_State *L);
 

src/server.cpp

@@ -2100,15 +2100,23 @@ s32 Server::playSound(const SimpleSoundSpec &spec,
 	m_playing_sounds[id] = ServerPlayingSound();
 	ServerPlayingSound &psound = m_playing_sounds[id];
 	psound.params = params;
+	psound.spec = spec;
 
+	float gain = params.gain * spec.gain;
 	NetworkPacket pkt(TOCLIENT_PLAY_SOUND, 0);
-	pkt << id << spec.name << (float) (spec.gain * params.gain)
-			<< (u8) params.type << pos << params.object << params.loop;
+	pkt << id << spec.name << gain
+			<< (u8) params.type << pos << params.object
+			<< params.loop << params.fade;
 
-	for(std::vector<u16>::iterator i = dst_clients.begin();
+	// Backwards compability
+	bool play_sound = gain > 0;
+
+	for (std::vector<u16>::iterator i = dst_clients.begin();
 			i != dst_clients.end(); ++i) {
-		psound.clients.insert(*i);
-		m_clients.send(*i, 0, &pkt, true);
+		if (play_sound || m_clients.getProtocolVersion(*i) >= 32) {
+			psound.clients.insert(*i);
+			m_clients.send(*i, 0, &pkt, true);
+		}
 	}
 	return id;
 }
@@ -2132,6 +2140,52 @@ void Server::stopSound(s32 handle)
 	m_playing_sounds.erase(i);
 }
 
+void Server::fadeSound(s32 handle, float step, float gain)
+{
+	// Get sound reference
+	UNORDERED_MAP<s32, ServerPlayingSound>::iterator i =
+			m_playing_sounds.find(handle);
+	if (i == m_playing_sounds.end())
+		return;
+
+	ServerPlayingSound &psound = i->second;
+	psound.params.gain = gain;
+
+	NetworkPacket pkt(TOCLIENT_FADE_SOUND, 4);
+	pkt << handle << step << gain;
+
+	// Backwards compability
+	bool play_sound = gain > 0;
+	ServerPlayingSound compat_psound = psound;
+	compat_psound.clients.clear();
+
+	NetworkPacket compat_pkt(TOCLIENT_STOP_SOUND, 4);
+	compat_pkt << handle;
+
+	for (UNORDERED_SET<u16>::iterator it = psound.clients.begin();
+			it != psound.clients.end();) {
+		if (m_clients.getProtocolVersion(*it) >= 32) {
+			// Send as reliable
+			m_clients.send(*it, 0, &pkt, true);
+			++it;
+		} else {
+			compat_psound.clients.insert(*it);
+			// Stop old sound
+			m_clients.send(*it, 0, &compat_pkt, true);
+			psound.clients.erase(it++);
+		}
+	}
+
+	// Remove sound reference
+	if (!play_sound || psound.clients.size() == 0)
+		m_playing_sounds.erase(i);
+
+	if (play_sound && compat_psound.clients.size() > 0) {
+		// Play new sound volume on older clients
+		playSound(compat_psound.spec, compat_psound.params);
+	}
+}
+
 void Server::sendRemoveNode(v3s16 p, u16 ignore_id,
 	std::vector<u16> *far_players, float far_d_nodes)
 {

src/server.h

@@ -115,6 +115,7 @@ struct ServerSoundParams
 	u16 object;
 	float max_hear_distance;
 	bool loop;
+	float fade;
 
 	ServerSoundParams():
 		gain(1.0),
@@ -123,7 +124,8 @@ struct ServerSoundParams
 		pos(0,0,0),
 		object(0),
 		max_hear_distance(32*BS),
-		loop(false)
+		loop(false),
+		fade(0)
 	{}
 
 	v3f getPos(ServerEnvironment *env, bool *pos_exists) const;
@@ -132,6 +134,7 @@ struct ServerSoundParams
 struct ServerPlayingSound
 {
 	ServerSoundParams params;
+	SimpleSoundSpec spec;
 	UNORDERED_SET<u16> clients; // peer ids
 };
 
@@ -231,6 +234,7 @@ class Server : public con::PeerHandler, public MapEventReceiver,
 	// Envlock
 	s32 playSound(const SimpleSoundSpec &spec, const ServerSoundParams &params);
 	void stopSound(s32 handle);
+	void fadeSound(s32 handle, float step, float gain);
 
 	// Envlock
 	std::set<std::string> getPlayerEffectivePrivs(const std::string &name);

src/sound.h

@@ -34,22 +34,22 @@ class OnDemandSoundFetcher
 
 struct SimpleSoundSpec
 {
-	SimpleSoundSpec(const std::string &name = "", float gain = 1.0)
-	    : name(name), gain(gain)
+	SimpleSoundSpec(const std::string &name = "", float gain = 1.0, float fade = 0.0)
+	    : name(name), gain(gain), fade(fade)
 	{
 	}
 
 	bool exists() const { return name != ""; }
 
 	std::string name;
 	float gain;
+	float fade;
 };
 
 class ISoundManager
 {
 public:
 	virtual ~ISoundManager() {}
-
 	// Multiple sounds can be loaded per name; when played, the sound
 	// should be chosen randomly from alternatives
 	// Return value determines success/failure
@@ -63,16 +63,21 @@ class ISoundManager
 
 	// playSound functions return -1 on failure, otherwise a handle to the
 	// sound. If name=="", call should be ignored without error.
-	virtual int playSound(const std::string &name, bool loop, float volume) = 0;
-	virtual int playSoundAt(
-			const std::string &name, bool loop, float volume, v3f pos) = 0;
+	virtual int playSound(const std::string &name, bool loop, float volume,
+			float fade = 0) = 0;
+	virtual int playSoundAt(const std::string &name, bool loop, float volume,
+			v3f pos) = 0;
 	virtual void stopSound(int sound) = 0;
 	virtual bool soundExists(int sound) = 0;
 	virtual void updateSoundPosition(int sound, v3f pos) = 0;
+	virtual bool updateSoundGain(int id, float gain) = 0;
+	virtual float getSoundGain(int id) = 0;
+	virtual void step(float dtime) = 0;
+	virtual void fadeSound(int sound, float step, float gain) = 0;
 
 	int playSound(const SimpleSoundSpec &spec, bool loop)
 	{
-		return playSound(spec.name, loop, spec.gain);
+		return playSound(spec.name, loop, spec.gain, spec.fade);
 	}
 	int playSoundAt(const SimpleSoundSpec &spec, bool loop, v3f pos)
 	{
@@ -93,14 +98,21 @@ class DummySoundManager : public ISoundManager
 	}
 	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 playSound(const std::string &name, bool loop, float volume, float fade)
+	{
+		return 0;
+	}
 	int playSoundAt(const std::string &name, bool loop, float volume, v3f pos)
 	{
 		return 0;
 	}
 	void stopSound(int sound) {}
 	bool soundExists(int sound) { return false; }
 	void updateSoundPosition(int sound, v3f pos) {}
+	bool updateSoundGain(int id, float gain) { return false; }
+	float getSoundGain(int id) { return 0; }
+	void step(float dtime) { }
+	void fadeSound(int sound, float step, float gain) { }
 };
 
 // Global DummySoundManager singleton