Preliminary "active block" stuff + set up test code to grow grass.

14 files changed, 843 insertions, 378 deletions

diff --git a/src/client.cpp b/src/client.cpp
index e2cda97c1..c85d6e9e2 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -1193,31 +1193,23 @@ void Client::ProcessData(u8 *data, u32 datasize, u16 sender_peer_id)
 		if(datasize < 4)
 			return;
 		
-		u16 time = readU16(&data[2]);
-		time = time % 24000;
-		m_time_of_day = time;
-		//dstream<<"Client: time="<<time<<std::endl;
+		u16 time_of_day = readU16(&data[2]);
+		time_of_day = time_of_day % 24000;
+		//dstream<<"Client: time_of_day="<<time_of_day<<std::endl;
 		
 		/*
-			Day/night
-
 			time_of_day:
 			0 = midnight
 			12000 = midday
 		*/
 		{
-			u32 dr = time_to_daynight_ratio(m_time_of_day);
+			m_env.setTimeOfDay(time_of_day);
+
+			u32 dr = m_env.getDayNightRatio();
 
-			dstream<<"Client: time_of_day="<<m_time_of_day
+			dstream<<"Client: time_of_day="<<time_of_day
 					<<", dr="<<dr
 					<<std::endl;
-			
-			if(dr != m_env.getDayNightRatio())
-			{
-				dout_client<<DTIME<<"Client: changing day-night ratio"<<std::endl;
-				m_env.setDayNightRatio(dr);
-				m_env.expireMeshes(true);
-			}
 		}
 
 	}
diff --git a/src/environment.cpp b/src/environment.cpp
index 24ec66757..f233eaf7f 100644
--- a/src/environment.cpp
+++ b/src/environment.cpp
@@ -23,9 +23,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "collision.h"
 
 
-Environment::Environment()
+Environment::Environment():
+	m_time_of_day(9000)
 {
-	m_daynight_ratio = 0.5;
 }
 
 Environment::~Environment()
@@ -174,14 +174,84 @@ void Environment::printPlayers(std::ostream &o)
 	}
 }
 
-void Environment::setDayNightRatio(u32 r)
+/*void Environment::setDayNightRatio(u32 r)
 {
-	m_daynight_ratio = r;
-}
+	getDayNightRatio() = r;
+}*/
 
 u32 Environment::getDayNightRatio()
 {
-	return m_daynight_ratio;
+	//return getDayNightRatio();
+	return time_to_daynight_ratio(m_time_of_day);
+}
+
+/*
+	ActiveBlockList
+*/
+
+void fillRadiusBlock(v3s16 p0, s16 r, core::map<v3s16, bool> &list)
+{
+	v3s16 p;
+	for(p.X=p0.X-r; p.X<=p0.X+r; p.X++)
+	for(p.Y=p0.Y-r; p.Y<=p0.Y+r; p.Y++)
+	for(p.Z=p0.Z-r; p.Z<=p0.Z+r; p.Z++)
+	{
+		// Set in list
+		list[p] = true;
+	}
+}
+
+void ActiveBlockList::update(core::list<v3s16> &active_positions,
+		s16 radius,
+		core::map<v3s16, bool> &blocks_removed,
+		core::map<v3s16, bool> &blocks_added)
+{
+	/*
+		Create the new list
+	*/
+	core::map<v3s16, bool> newlist;
+	for(core::list<v3s16>::Iterator i = active_positions.begin();
+			i != active_positions.end(); i++)
+	{
+		fillRadiusBlock(*i, radius, newlist);
+	}
+
+	/*
+		Find out which blocks on the old list are not on the new list
+	*/
+	// Go through old list
+	for(core::map<v3s16, bool>::Iterator i = m_list.getIterator();
+			i.atEnd()==false; i++)
+	{
+		v3s16 p = i.getNode()->getKey();
+		// If not on new list, it's been removed
+		if(newlist.find(p) == NULL)
+			blocks_removed.insert(p, true);
+	}
+
+	/*
+		Find out which blocks on the new list are not on the old list
+	*/
+	// Go through new list
+	for(core::map<v3s16, bool>::Iterator i = newlist.getIterator();
+			i.atEnd()==false; i++)
+	{
+		v3s16 p = i.getNode()->getKey();
+		// If not on old list, it's been added
+		if(m_list.find(p) == NULL)
+			blocks_added.insert(p, true);
+	}
+
+	/*
+		Update m_list
+	*/
+	m_list.clear();
+	for(core::map<v3s16, bool>::Iterator i = newlist.getIterator();
+			i.atEnd()==false; i++)
+	{
+		v3s16 p = i.getNode()->getKey();
+		m_list.insert(p, true);
+	}
 }
 
 /*
@@ -192,16 +262,20 @@ ServerEnvironment::ServerEnvironment(ServerMap *map, Server *server):
 	m_map(map),
 	m_server(server),
 	m_random_spawn_timer(3),
-	m_send_recommended_timer(0)
+	m_send_recommended_timer(0),
+	m_game_time(0),
+	m_game_time_fraction_counter(0)
 {
 }
 
 ServerEnvironment::~ServerEnvironment()
 {
-	/*
-		Convert all objects to static (thus delete the active objects)
-	*/
-	deactivateFarObjects(-1);
+	// Clear active block list.
+	// This makes the next one delete all active objects.
+	m_active_blocks.clear();
+
+	// Convert all objects to static and delete the active objects
+	deactivateFarObjects(true);
 
 	// Drop/delete map
 	m_map->drop();
@@ -384,7 +458,71 @@ void ServerEnvironment::deSerializePlayers(const std::string &savedir)
 	}
 }
 
+void ServerEnvironment::saveMeta(const std::string &savedir)
+{
+	std::string path = savedir + "/env_meta.txt";
+
+	// Open file and serialize
+	std::ofstream os(path.c_str(), std::ios_base::binary);
+	if(os.good() == false)
+	{
+		dstream<<"WARNING: ServerEnvironment::saveMeta(): Failed to open "
+				<<path<<std::endl;
+		throw SerializationError("Couldn't save env meta");
+	}
+
+	Settings args;
+	args.setU64("game_time", m_game_time);
+	args.setU64("time_of_day", getTimeOfDay());
+	args.writeLines(os);
+	os<<"EnvArgsEnd\n";
+}
+
+void ServerEnvironment::loadMeta(const std::string &savedir)
+{
+	std::string path = savedir + "/env_meta.txt";
+
+	// Open file and deserialize
+	std::ifstream is(path.c_str(), std::ios_base::binary);
+	if(is.good() == false)
+	{
+		dstream<<"WARNING: ServerEnvironment::loadMeta(): Failed to open "
+				<<path<<std::endl;
+		throw SerializationError("Couldn't load env meta");
+	}
+
+	Settings args;
+	
+	for(;;)
+	{
+		if(is.eof())
+			throw SerializationError
+					("ServerEnvironment::loadMeta(): EnvArgsEnd not found");
+		std::string line;
+		std::getline(is, line);
+		std::string trimmedline = trim(line);
+		if(trimmedline == "EnvArgsEnd")
+			break;
+		args.parseConfigLine(line);
+	}
+	
+	try{
+		m_game_time = args.getU64("game_time");
+	}catch(SettingNotFoundException &e){
+		// Getting this is crucial, otherwise timestamps are useless
+		throw SerializationError("Couldn't load env meta game_time");
+	}
+
+	try{
+		m_time_of_day = args.getU64("time_of_day");
+	}catch(SettingNotFoundException &e){
+		// This is not as important
+		m_time_of_day = 9000;
+	}
+}
+
 #if 0
+// This is probably very useless
 void spawnRandomObjects(MapBlock *block)
 {
 	for(s16 z0=0; z0<MAP_BLOCKSIZE; z0++)
@@ -440,9 +578,21 @@ void ServerEnvironment::step(float dtime)
 	//TimeTaker timer("ServerEnv step");
 
 	// Get some settings
-	//bool free_move = g_settings.getBool("free_move");
 	bool footprints = g_settings.getBool("footprints");
 
+	/*
+		Increment game time
+	*/
+	{
+		m_game_time_fraction_counter += dtime;
+		u32 inc_i = (u32)m_game_time_fraction_counter;
+		m_game_time += inc_i;
+		m_game_time_fraction_counter -= (float)inc_i;
+	}
+	
+	/*
+		Let map update it's timers
+	*/
 	{
 		//TimeTaker timer("Server m_map->timerUpdate()");
 		m_map->timerUpdate(dtime);
@@ -487,11 +637,187 @@ void ServerEnvironment::step(float dtime)
 	}
 
 	/*
+		Manage active block list
+	*/
+	if(m_active_blocks_management_interval.step(dtime, 2.0))
+	{
+		/*
+			Get player block positions
+		*/
+		core::list<v3s16> players_blockpos;
+		for(core::list<Player*>::Iterator
+				i = m_players.begin();
+				i != m_players.end(); i++)
+		{
+			Player *player = *i;
+			// Ignore disconnected players
+			if(player->peer_id == 0)
+				continue;
+			v3s16 blockpos = getNodeBlockPos(
+					floatToInt(player->getPosition(), BS));
+			players_blockpos.push_back(blockpos);
+		}
+		
+		/*
+			Update list of active blocks, collecting changes
+		*/
+		const s16 active_block_range = 5;
+		core::map<v3s16, bool> blocks_removed;
+		core::map<v3s16, bool> blocks_added;
+		m_active_blocks.update(players_blockpos, active_block_range,
+				blocks_removed, blocks_added);
+
+		/*
+			Handle removed blocks
+		*/
+
+		// Convert active objects that are no more in active blocks to static
+		deactivateFarObjects(false);
+		
+		for(core::map<v3s16, bool>::Iterator
+				i = blocks_removed.getIterator();
+				i.atEnd()==false; i++)
+		{
+			v3s16 p = i.getNode()->getKey();
+
+			/*dstream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
+					<<") became inactive"<<std::endl;*/
+			
+			MapBlock *block = m_map->getBlockNoCreateNoEx(p);
+			if(block==NULL)
+				continue;
+			
+			// Set current time as timestamp
+			block->setTimestamp(m_game_time);
+		}
+
+		/*
+			Handle added blocks
+		*/
+
+		for(core::map<v3s16, bool>::Iterator
+				i = blocks_added.getIterator();
+				i.atEnd()==false; i++)
+		{
+			v3s16 p = i.getNode()->getKey();
+			
+			/*dstream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
+					<<") became active"<<std::endl;*/
+
+			MapBlock *block = m_map->getBlockNoCreateNoEx(p);
+			if(block==NULL)
+				continue;
+			
+			// Get time difference
+			u32 dtime_s = 0;
+			u32 stamp = block->getTimestamp();
+			if(m_game_time > stamp && stamp != BLOCK_TIMESTAMP_UNDEFINED)
+				dtime_s = m_game_time - block->getTimestamp();
+
+			// Set current time as timestamp
+			block->setTimestamp(m_game_time);
+
+			//dstream<<"Block is "<<dtime_s<<" seconds old."<<std::endl;
+			
+			// Activate stored objects
+			activateObjects(block);
+
+			// TODO: Do something
+			
+			// Here's a quick demonstration
+			v3s16 p0;
+			for(p0.X=0; p0.X<MAP_BLOCKSIZE; p0.X++)
+			for(p0.Y=0; p0.Y<MAP_BLOCKSIZE; p0.Y++)
+			for(p0.Z=0; p0.Z<MAP_BLOCKSIZE; p0.Z++)
+			{
+				v3s16 p = p0 + block->getPosRelative();
+				MapNode n = block->getNodeNoEx(p0);
+				// Test something:
+				// Convert all mud under proper day lighting to grass
+				if(n.d == CONTENT_MUD)
+				{
+					if(1)
+					{
+						MapNode n_top = block->getNodeNoEx(p0+v3s16(0,1,0));
+						if(content_features(n_top.d).walkable == false &&
+								n_top.getLight(LIGHTBANK_DAY) >= 13)
+						{
+							n.d = CONTENT_GRASS;
+							m_map->addNodeWithEvent(p, n);
+						}
+					}
+				}
+			}
+		}
+	}
+
+	/*
+		Mess around in active blocks
+	*/
+	if(m_active_blocks_test_interval.step(dtime, 5.0))
+	{
+		for(core::map<v3s16, bool>::Iterator
+				i = m_active_blocks.m_list.getIterator();
+				i.atEnd()==false; i++)
+		{
+			v3s16 p = i.getNode()->getKey();
+			
+			/*dstream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
+					<<") being handled"<<std::endl;*/
+
+			MapBlock *block = m_map->getBlockNoCreateNoEx(p);
+			if(block==NULL)
+				continue;
+			
+			// Set current time as timestamp
+			block->setTimestamp(m_game_time);
+			
+			/*
+				Do stuff!
+
+				Note that map modifications should be done using the event-
+				making map methods so that the server gets information
+				about them.
+
+				Reading can be done quickly directly from the block.
+
+				Everything should bind to inside this single content
+				searching loop to keep things fast.
+			*/
+
+			v3s16 p0;
+			for(p0.X=0; p0.X<MAP_BLOCKSIZE; p0.X++)
+			for(p0.Y=0; p0.Y<MAP_BLOCKSIZE; p0.Y++)
+			for(p0.Z=0; p0.Z<MAP_BLOCKSIZE; p0.Z++)
+			{
+				v3s16 p = p0 + block->getPosRelative();
+				MapNode n = block->getNodeNoEx(p0);
+				// Test something:
+				// Convert mud under proper lighting to grass
+				if(n.d == CONTENT_MUD)
+				{
+					if(myrand()%4 == 0)
+					{
+						MapNode n_top = block->getNodeNoEx(p0+v3s16(0,1,0));
+						if(content_features(n_top.d).walkable == false &&
+								n_top.getLightBlend(getDayNightRatio()) >= 13)
+						{
+							n.d = CONTENT_GRASS;
+							m_map->addNodeWithEvent(p, n);
+						}
+					}
+				}
+			}
+		}
+	}
+	
+	/*
 		Step active objects
 	*/
 	{
 		//TimeTaker timer("Step active objects");
-
+		
+		// This helps the objects to send data at the same time
 		bool send_recommended = false;
 		m_send_recommended_timer += dtime;
 		if(m_send_recommended_timer > 0.15)
@@ -505,33 +831,23 @@ void ServerEnvironment::step(float dtime)
 				i.atEnd()==false; i++)
 		{
 			ServerActiveObject* obj = i.getNode()->getValue();
+			// Don't step if is to be removed or stored statically
+			if(obj->m_removed || obj->m_pending_deactivation)
+				continue;
 			// Step object, putting messages directly to the queue
 			obj->step(dtime, m_active_object_messages, send_recommended);
 		}
 	}
-
+	
+	/*
+		Manage active objects
+	*/
 	if(m_object_management_interval.step(dtime, 0.5))
 	{
-		//TimeTaker timer("ServerEnv object management");
-
-		const s16 to_active_range_blocks = 3;
-		const s16 to_static_range_blocks = 4;
-		//const f32 to_static_max_f = (to_active_max_blocks+2)*MAP_BLOCKSIZE*BS;
-
 		/*
 			Remove objects that satisfy (m_removed && m_known_by_count==0)
 		*/
 		removeRemovedObjects();
-		
-		/*
-			Convert stored objects from blocks near the players to active.
-		*/
-		activateNearObjects(to_active_range_blocks);
-
-		/*
-			Convert objects that are far away from all the players to static.
-		*/
-		deactivateFarObjects(to_static_range_blocks);
 	}
 
 	if(g_settings.getBool("enable_experimental"))
@@ -791,11 +1107,18 @@ void ServerEnvironment::removeRemovedObjects()
 			objects_to_remove.push_back(id);
 			continue;
 		}
-		// If not m_removed, don't remove.
-		if(obj->m_removed == false)
+
+		/*
+			We will delete objects that are marked as removed or thatare
+			waiting for deletion after deactivation
+		*/
+		if(obj->m_removed == false && obj->m_pending_deactivation == false)
 			continue;
-		// Delete static data from block
-		if(obj->m_static_exists)
+
+		/*
+			Delete static data from block if is marked as removed
+		*/
+		if(obj->m_static_exists && obj->m_removed)
 		{
 			MapBlock *block = m_map->getBlockNoCreateNoEx(obj->m_static_block);
 			if(block)
@@ -804,9 +1127,11 @@ void ServerEnvironment::removeRemovedObjects()
 				block->setChangedFlag();
 			}
 		}
+
 		// If m_known_by_count > 0, don't actually remove.
 		if(obj->m_known_by_count > 0)
 			continue;
+		
 		// Delete
 		delete obj;
 		// Id to be removed from m_active_objects
@@ -823,82 +1148,62 @@ void ServerEnvironment::removeRemovedObjects()
 /*
 	Convert stored objects from blocks near the players to active.
 */
-void ServerEnvironment::activateNearObjects(s16 range_blocks)
+void ServerEnvironment::activateObjects(MapBlock *block)
 {
-	for(core::list<Player*>::Iterator i = m_players.begin();
-			i != m_players.end(); i++)
+	if(block==NULL)
+		return;
+	// Ignore if no stored objects (to not set changed flag)
+	if(block->m_static_objects.m_stored.size() == 0)
+		return;
+	// A list for objects that couldn't be converted to static for some
+	// reason. They will be stored back.
+	core::list<StaticObject> new_stored;
+	// Loop through stored static objects
+	for(core::list<StaticObject>::Iterator
+			i = block->m_static_objects.m_stored.begin();
+			i != block->m_static_objects.m_stored.end(); i++)
 	{
-		Player *player = *i;
-		
-		// Ignore disconnected players
-		if(player->peer_id == 0)
-			continue;
-
-		v3f playerpos = player->getPosition();
-		
-		v3s16 blockpos0 = getNodeBlockPos(floatToInt(playerpos, BS));
-		v3s16 bpmin = blockpos0 - v3s16(1,1,1)*range_blocks;
-		v3s16 bpmax = blockpos0 + v3s16(1,1,1)*range_blocks;
-		// Loop through all nearby blocks
-		for(s16 x=bpmin.X; x<=bpmax.X; x++)
-		for(s16 y=bpmin.Y; y<=bpmax.Y; y++)
-		for(s16 z=bpmin.Z; z<=bpmax.Z; z++)
+		/*dstream<<"INFO: Server: Creating an active object from "
+				<<"static data"<<std::endl;*/
+		StaticObject &s_obj = *i;
+		// Create an active object from the data
+		ServerActiveObject *obj = ServerActiveObject::create
+				(s_obj.type, this, 0, s_obj.pos, s_obj.data);
+		// If couldn't create object, store static data back.
+		if(obj==NULL)
 		{
-			v3s16 blockpos(x,y,z);
-			MapBlock *block = m_map->getBlockNoCreateNoEx(blockpos);
-			if(block==NULL)
-				continue;
-			// Ignore if no stored objects (to not set changed flag)
-			if(block->m_static_objects.m_stored.size() == 0)
-				continue;
-			// This will contain the leftovers of the stored list
-			core::list<StaticObject> new_stored;
-			// Loop through stored static objects
-			for(core::list<StaticObject>::Iterator
-					i = block->m_static_objects.m_stored.begin();
-					i != block->m_static_objects.m_stored.end(); i++)
-			{
-				/*dstream<<"INFO: Server: Creating an active object from "
-						<<"static data"<<std::endl;*/
-				StaticObject &s_obj = *i;
-				// Create an active object from the data
-				ServerActiveObject *obj = ServerActiveObject::create
-						(s_obj.type, this, 0, s_obj.pos, s_obj.data);
-				if(obj==NULL)
-				{
-					// This is necessary to preserve stuff during bugs
-					// and errors
-					new_stored.push_back(s_obj);
-					continue;
-				}
-				// This will also add the object to the active static list
-				addActiveObject(obj);
-				//u16 id = addActiveObject(obj);
-			}
-			// Clear stored list
-			block->m_static_objects.m_stored.clear();
-			// Add leftover stuff to stored list
-			for(core::list<StaticObject>::Iterator
-					i = new_stored.begin();
-					i != new_stored.end(); i++)
-			{
-				StaticObject &s_obj = *i;
-				block->m_static_objects.m_stored.push_back(s_obj);
-			}
-			block->setChangedFlag();
+			new_stored.push_back(s_obj);
+			continue;
 		}
+		// This will also add the object to the active static list
+		addActiveObject(obj);
+		//u16 id = addActiveObject(obj);
 	}
+	// Clear stored list
+	block->m_static_objects.m_stored.clear();
+	// Add leftover failed stuff to stored list
+	for(core::list<StaticObject>::Iterator
+			i = new_stored.begin();
+			i != new_stored.end(); i++)
+	{
+		StaticObject &s_obj = *i;
+		block->m_static_objects.m_stored.push_back(s_obj);
+	}
+	// Block has been modified
+	block->setChangedFlag();
 }
 
 /*
-	Convert objects that are far away from all the players to static.
+	Convert objects that are not in active blocks to static.
+
+	If m_known_by_count != 0, active object is not deleted, but static
+	data is still updated.
 
-	If range_blocks == -1, convert everything to static even if known
-	by a player.
+	If force_delete is set, active object is deleted nevertheless. It
+	shall only be set so in the destructor of the environment.
 */
-void ServerEnvironment::deactivateFarObjects(s16 range_blocks)
+void ServerEnvironment::deactivateFarObjects(bool force_delete)
 {
-	bool force_everything = (range_blocks == -1);
 	core::list<u16> objects_to_remove;
 	for(core::map<u16, ServerActiveObject*>::Iterator
 			i = m_active_objects.getIterator();
@@ -917,46 +1222,15 @@ void ServerEnvironment::deactivateFarObjects(s16 range_blocks)
 			continue;
 		}
 
-		if(force_everything == false)
-		{
-			// If known by some client, don't convert to static.
-			if(obj->m_known_by_count > 0)
-				continue;
-			
-			// If close to some player, don't convert to static.
-			bool close_to_player = false;
-			for(core::list<Player*>::Iterator i = m_players.begin();
-					i != m_players.end(); i++)
-			{
-				Player *player = *i;
-				
-				// Ignore disconnected players
-				if(player->peer_id == 0)
-					continue;
-
-				v3f playerpos = player->getPosition();
-
-				v3s16 blockpos_p = getNodeBlockPos(floatToInt(playerpos, BS));
-				v3s16 blockpos_o = getNodeBlockPos(floatToInt(objectpos, BS));
-
-				if(blockpos_p.X >= blockpos_o.X - range_blocks
-					&& blockpos_p.Y >= blockpos_o.Y - range_blocks
-					&& blockpos_p.Z >= blockpos_o.Z - range_blocks
-					&& blockpos_p.X <= blockpos_o.X + range_blocks
-					&& blockpos_p.Y <= blockpos_o.Y + range_blocks
-					&& blockpos_p.Z <= blockpos_o.Z + range_blocks)
-				{
-					close_to_player = true;
-					break;
-				}
-			}
-
-			if(close_to_player)
-				continue;
-		}
+		// The block in which the object resides in
+		v3s16 blockpos_o = getNodeBlockPos(floatToInt(objectpos, BS));
+		
+		// If block is active, don't remove
+		if(m_active_blocks.contains(blockpos_o))
+			continue;
 
 		/*
-			Update the static data and remove the active object.
+			Update the static data
 		*/
 
 		// Delete old static object
@@ -971,7 +1245,7 @@ void ServerEnvironment::deactivateFarObjects(s16 range_blocks)
 				oldblock = block;
 			}
 		}
-		// Add new static object
+		// Create new static object
 		std::string staticdata = obj->getStaticData();
 		StaticObject s_obj(obj->getType(), objectpos, staticdata);
 		// Add to the block where the object is located in
@@ -998,6 +1272,19 @@ void ServerEnvironment::deactivateFarObjects(s16 range_blocks)
 			obj->m_static_exists = false;
 			continue;
 		}
+
+		/*
+			Delete active object if not known by some client,
+			else set pending deactivation
+		*/
+
+		// If known by some client, don't delete.
+		if(obj->m_known_by_count > 0 && force_delete == false)
+		{
+			obj->m_pending_deactivation = true;
+			continue;
+		}
+		
 		/*dstream<<"INFO: Server: Stored static data. Deleting object."
 				<<std::endl;*/
 		// Delete active object
@@ -1005,6 +1292,7 @@ void ServerEnvironment::deactivateFarObjects(s16 range_blocks)
 		// Id to be removed from m_active_objects
 		objects_to_remove.push_back(id);
 	}
+
 	// Remove references from m_active_objects
 	for(core::list<u16>::Iterator i = objects_to_remove.begin();
 			i != objects_to_remove.end(); i++)
@@ -1230,7 +1518,7 @@ void ClientEnvironment::step(float dtime)
 				// Get node at head
 				v3s16 p = floatToInt(playerpos + v3f(0,BS+BS/2,0), BS);
 				MapNode n = m_map->getNode(p);
-				light = n.getLightBlend(m_daynight_ratio);
+				light = n.getLightBlend(getDayNightRatio());
 			}
 			catch(InvalidPositionException &e) {}
 			player->updateLight(light);
@@ -1254,7 +1542,7 @@ void ClientEnvironment::step(float dtime)
 					{
 						v3s16 p_blocks = getNodeBlockPos(bottompos);
 						MapBlock *b = m_map->getBlockNoCreate(p_blocks);
-						//b->updateMesh(m_daynight_ratio);
+						//b->updateMesh(getDayNightRatio());
 						b->setMeshExpired(true);
 					}
 				}
@@ -1283,7 +1571,7 @@ void ClientEnvironment::step(float dtime)
 			// Get node at head
 			v3s16 p = obj->getLightPosition();
 			MapNode n = m_map->getNode(p);
-			light = n.getLightBlend(m_daynight_ratio);
+			light = n.getLightBlend(getDayNightRatio());
 		}
 		catch(InvalidPositionException &e) {}
 		obj->updateLight(light);
@@ -1292,7 +1580,7 @@ void ClientEnvironment::step(float dtime)
 
 void ClientEnvironment::updateMeshes(v3s16 blockpos)
 {
-	m_map->updateMeshes(blockpos, m_daynight_ratio);
+	m_map->updateMeshes(blockpos, getDayNightRatio());
 }
 
 void ClientEnvironment::expireMeshes(bool only_daynight_diffed)
diff --git a/src/environment.h b/src/environment.h
index 971ded5c9..e32b15dbb 100644
--- a/src/environment.h
+++ b/src/environment.h
@@ -64,14 +64,52 @@ public:
 	core::list<Player*> getPlayers(bool ignore_disconnected);
 	void printPlayers(std::ostream &o);
 	
-	void setDayNightRatio(u32 r);
+	//void setDayNightRatio(u32 r);
 	u32 getDayNightRatio();
+	
+	// 0-23999
+	virtual void setTimeOfDay(u32 time)
+	{
+		m_time_of_day = time;
+	}
+
+	u32 getTimeOfDay()
+	{
+		return m_time_of_day;
+	}
 
 protected:
 	// peer_ids in here should be unique, except that there may be many 0s
 	core::list<Player*> m_players;
 	// Brightness
-	u32 m_daynight_ratio;
+	//u32 m_daynight_ratio;
+	// Time of day in milli-hours (0-23999); determines day and night
+	u32 m_time_of_day;
+};
+
+/*
+	List of active blocks, used by ServerEnvironment
+*/
+
+class ActiveBlockList
+{
+public:
+	void update(core::list<v3s16> &active_positions,
+			s16 radius,
+			core::map<v3s16, bool> &blocks_removed,
+			core::map<v3s16, bool> &blocks_added);
+
+	bool contains(v3s16 p){
+		return (m_list.find(p) != NULL);
+	}
+
+	void clear(){
+		m_list.clear();
+	}
+
+	core::map<v3s16, bool> m_list;
+
+private:
 };
 
 /*
@@ -106,11 +144,20 @@ public:
 	}
 
 	void step(f32 dtime);
-
+	
+	/*
+		Save players
+	*/
 	void serializePlayers(const std::string &savedir);
 	void deSerializePlayers(const std::string &savedir);
 
 	/*
+		Save and load time of day and game timer
+	*/
+	void saveMeta(const std::string &savedir);
+	void loadMeta(const std::string &savedir);
+
+	/*
 		ActiveObjects
 	*/
 
@@ -153,25 +200,48 @@ private:
 		Remove all objects that satisfy (m_removed && m_known_by_count==0)
 	*/
 	void removeRemovedObjects();
+	
 	/*
-		Convert stored objects from blocks near the players to active.
+		Convert stored objects from block to active
 	*/
-	void activateNearObjects(s16 range_blocks);
+	void activateObjects(MapBlock *block);
+	
 	/*
-		Convert objects that are far away from all the players to static.
+		Convert objects that are not in active blocks to static.
 
-		If range_blocks == -1, convert everything to static even if known
-		by a player.
+		If m_known_by_count != 0, active object is not deleted, but static
+		data is still updated.
+
+		If force_delete is set, active object is deleted nevertheless. It
+		shall only be set so in the destructor of the environment.
+	*/
+	void deactivateFarObjects(bool force_delete);
+
+	/*
+		Member variables
 	*/
-	void deactivateFarObjects(s16 range_blocks);
 	
+	// The map
 	ServerMap *m_map;
+	// Pointer to server (which is handling this environment)
 	Server *m_server;
+	// Active object list
 	core::map<u16, ServerActiveObject*> m_active_objects;
+	// Outgoing network message buffer for active objects
 	Queue<ActiveObjectMessage> m_active_object_messages;
-	float m_random_spawn_timer;
+	// Some timers
+	float m_random_spawn_timer; // used for experimental code
 	float m_send_recommended_timer;
 	IntervalLimiter m_object_management_interval;
+	// List of active blocks
+	ActiveBlockList m_active_blocks;
+	IntervalLimiter m_active_blocks_management_interval;
+	IntervalLimiter m_active_blocks_test_interval;
+	// Time from the beginning of the game in seconds.
+	// Incremented in step().
+	u32 m_game_time;
+	// A helper variable for incrementing the latter
+	float m_game_time_fraction_counter;
 };
 
 #ifndef SERVER
@@ -228,6 +298,20 @@ public:
 	void updateMeshes(v3s16 blockpos);
 	void expireMeshes(bool only_daynight_diffed);
 
+	void setTimeOfDay(u32 time)
+	{
+		u32 old_dr = getDayNightRatio();
+
+		Environment::setTimeOfDay(time);
+
+		if(getDayNightRatio() != old_dr)
+		{
+			dout_client<<DTIME<<"ClientEnvironment: DayNightRatio changed"
+					<<" -> expiring meshes"<<std::endl;
+			expireMeshes(true);
+		}
+	}
+
 	/*
 		ActiveObjects
 	*/
diff --git a/src/main.cpp b/src/main.cpp
index 816d92118..c3b075732 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -27,10 +27,8 @@ NOTE: Global locale is now set at initialization
 NOTE: If VBO (EHM_STATIC) is used, remember to explicitly free the

       hardware buffer (it is not freed automatically)

 

-Random suggeestions (AKA very old suggestions that haven't been done):

-----------------------------------------------------------------------

-

-SUGG: Fix address to be ipv6 compatible

+Old, wild and random suggestions that probably won't be done:

+-------------------------------------------------------------

 

 SUGG: If player is on ground, mainly fetch ground-level blocks

 

@@ -83,6 +81,10 @@ SUGG: Background music based on cellular automata?
 

 SUGG: Simple light color information to air

 

+SUGG: Server-side objects could be moved based on nodes to enable very

+      lightweight operation and simple AI

+	- Not practical; client would still need to show smooth movement.

+

 Gaming ideas:

 -------------

 

@@ -137,6 +139,8 @@ Build system / running:
 Networking and serialization:

 -----------------------------

 

+SUGG: Fix address to be ipv6 compatible

+

 User Interface:

 ---------------

 

@@ -207,18 +211,47 @@ FIXME: Server sometimes goes into some infinite PeerNotFoundException loop
 FIXME: The new optimized map sending doesn't sometimes send enough blocks

        from big caves and such

 

+TODO: A list of "active blocks" in which stuff happens.

+	+ Add a never-resetted game timer to the server

+	+ Add a timestamp value to blocks

+	+ The simple rule: All blocks near some player are "active"

+	- Do stuff in real time in active blocks

+		+ Handle objects

+		TODO: Make proper hooks in here

+		- Grow grass, delete leaves without a tree

+		- Spawn some mobs based on some rules

+		- Transform cobble to mossy cobble near water

+		- Run a custom script

+		- ...And all kinds of other dynamic stuff

+	+ Keep track of when a block becomes active and becomes inactive

+	+ When a block goes inactive:

+		+ Store objects statically to block

+		+ Store timer value as the timestamp

+	+ When a block goes active:

+		+ Create active objects out of static objects

+		TODO: Make proper hooks in here

+		- Simulate the results of what would have happened if it would have

+		  been active for all the time

+		  	- Grow a lot of grass and so on

+	+ Initially it is fine to send information about every active object

+	  to every player. Eventually it should be modified to only send info

+	  about the nearest ones.

+	  	+ This was left to be done by the old system and it sends only the

+		  nearest ones.

+

 Objects:

 --------

 

-TODO: Get rid of MapBlockObjects and use ActiveObjects

+TODO: Get rid of MapBlockObjects and use only ActiveObjects

+	- Skipping the MapBlockObject data is nasty - there is no "total

+	  length" stored; have to make a SkipMBOs function which contains

+	  enough of the current code to skip them properly.

 

 SUGG: MovingObject::move and Player::move are basically the same.

       combine them.

-	  - NOTE: Player::move is more up-to-date.

-	  - NOTE: There is a simple move implementation now in collision.{h,cpp}

-

-SUGG: Server-side objects could be moved based on nodes to enable very

-      lightweight operation and simple AI

+	- NOTE: Player::move is more up-to-date.

+	- NOTE: There is a simple move implementation now in collision.{h,cpp}

+	- NOTE: MovingObject will be deleted (MapBlockObject)

 

 Map:

 ----

diff --git a/src/map.cpp b/src/map.cpp
index cd2ba9154..316d662a6 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -607,13 +607,13 @@ s16 Map::propagateSunlight(v3s16 start,
 		}
 		else
 		{
-			// Turn mud into grass
+			/*// Turn mud into grass
 			if(n.d == CONTENT_MUD)
 			{
 				n.d = CONTENT_GRASS;
 				block->setNode(relpos, n);
 				modified_blocks.insert(blockpos, block);
-			}
+			}*/
 
 			// Sunlight goes no further
 			break;
@@ -838,9 +838,6 @@ void Map::updateLighting(core::map<v3s16, MapBlock*> & a_blocks,
 }
 
 /*
-	This is called after changing a node from transparent to opaque.
-	The lighting value of the node should be left as-is after changing
-	other values. This sets the lighting value to 0.
 */
 void Map::addNodeAndUpdate(v3s16 p, MapNode n,
 		core::map<v3s16, MapBlock*> &modified_blocks)
@@ -877,12 +874,12 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
 	catch(InvalidPositionException &e)
 	{
 	}
-	
+
+#if 1
 	/*
-		If the new node doesn't propagate sunlight and there is
-		grass below, change it to mud
+		If the new node is solid and there is grass below, change it to mud
 	*/
-	if(content_features(n.d).sunlight_propagates == false)
+	if(content_features(n.d).walkable == true)
 	{
 		try{
 			MapNode bottomnode = getNode(bottompos);
@@ -898,6 +895,7 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
 		{
 		}
 	}
+#endif
 
 	/*
 		If the new node is mud and it is under sunlight, change it
@@ -5452,25 +5450,13 @@ void ServerMap::saveBlock(MapBlock *block)
 	*/
 	o.write((char*)&version, 1);
 	
+	// Write basic data
 	block->serialize(o, version);
-
-	/*
-		Versions up from 9 have block objects.
-	*/
-	if(version >= 9)
-	{
-		block->serializeObjects(o, version);
-	}
-	
-	/*
-		Versions up from 15 have static objects.
-	*/
-	if(version >= 15)
-	{
-		block->m_static_objects.serialize(o);
-	}
 	
-	// We just wrote it to the disk
+	// Write extra data stored on disk
+	block->serializeDiskExtra(o, version);
+
+	// We just wrote it to the disk so clear modified flag
 	block->resetChangedFlag();
 }
 
@@ -5515,33 +5501,20 @@ void ServerMap::loadBlock(std::string sectordir, std::string blockfile, MapSecto
 			created_new = true;
 		}
 		
-		// deserialize block data
+		// Read basic data
 		block->deSerialize(is, version);
-		
-		/*
-			Versions up from 9 have block objects.
-		*/
-		if(version >= 9)
-		{
-			block->updateObjects(is, version, NULL, 0);
-		}
 
-		/*
-			Versions up from 15 have static objects.
-		*/
-		if(version >= 15)
-		{
-			block->m_static_objects.deSerialize(is);
-		}
+		// Read extra data stored on disk
+		block->deSerializeDiskExtra(is, version);
 		
+		// If it's a new block, insert it to the map
 		if(created_new)
 			sector->insertBlock(block);
 		
 		/*
-			Convert old formats to new and save
+			Save blocks loaded in old format in new format
 		*/
 
-		// Save old format blocks in new format
 		if(version < SER_FMT_VER_HIGHEST || save_after_load)
 		{
 			saveBlock(block);
diff --git a/src/mapblock.cpp b/src/mapblock.cpp
index 58b23bd14..d62928ce2 100644
--- a/src/mapblock.cpp
+++ b/src/mapblock.cpp
@@ -1549,7 +1549,8 @@ MapBlock::MapBlock(NodeContainer *parent, v3s16 pos, bool dummy):
 		m_lighting_expired(true),
 		m_day_night_differs(false),
 		//m_not_fully_generated(false),
-		m_objects(this)
+		m_objects(this),
+		m_timestamp(BLOCK_TIMESTAMP_UNDEFINED)
 {
 	data = NULL;
 	if(dummy == false)
@@ -1720,17 +1721,17 @@ void MapBlock::replaceMesh(scene::SMesh *mesh_new)
 	Propagates sunlight down through the block.
 	Doesn't modify nodes that are not affected by sunlight.
 	
-	Returns false if sunlight at bottom block is invalid
+	Returns false if sunlight at bottom block is invalid.
+	Returns true if sunlight at bottom block is valid.
 	Returns true if bottom block doesn't exist.
 
 	If there is a block above, continues from it.
 	If there is no block above, assumes there is sunlight, unless
 	is_underground is set or highest node is water.
 
-	At the moment, all sunlighted nodes are added to light_sources.
-	- SUGG: This could be optimized
+	All sunlighted nodes are added to light_sources.
 
-	Turns sunglighted mud into grass.
+	If grow_grass==true, turns sunglighted mud into grass.
 
 	if remove_light==true, sets non-sunlighted nodes black.
 
@@ -1948,45 +1949,6 @@ void MapBlock::stepObjects(float dtime, bool server, u32 daynight_ratio)
 	*/
 	m_objects.step(dtime, server, daynight_ratio);
 
-#if 0
-	/*
-		Spawn some objects at random.
-
-		Use dayNightDiffed() to approximate being near ground level
-	*/
-	if(m_spawn_timer < -999)
-	{
-		m_spawn_timer = 60;
-	}
-	if(dayNightDiffed() == true && getObjectCount() == 0)
-	{
-		m_spawn_timer -= dtime;
-		if(m_spawn_timer <= 0.0)
-		{
-			m_spawn_timer += myrand() % 300;
-			
-			v2s16 p2d(
-				(myrand()%(MAP_BLOCKSIZE-1))+0,
-				(myrand()%(MAP_BLOCKSIZE-1))+0
-			);
-
-			s16 y = getGroundLevel(p2d);
-			
-			if(y >= 0)
-			{
-				v3s16 p(p2d.X, y+1, p2d.Y);
-
-				if(getNode(p).d == CONTENT_AIR
-						&& getNode(p).getLightBlend(daynight_ratio) <= 11)
-				{
-					RatObject *obj = new RatObject(NULL, -1, intToFloat(p, BS));
-					addObject(obj);
-				}
-			}
-		}
-	}
-#endif
-
 	setChangedFlag();
 }
 
@@ -2359,6 +2321,8 @@ void MapBlock::deSerialize(std::istream &is, u8 version)
 	/*
 		Translate nodes as specified in the translate_to fields of
 		node features
+
+		NOTE: This isn't really used. Should it be removed?
 	*/
 	for(u32 i=0; i<MAP_BLOCKSIZE*MAP_BLOCKSIZE*MAP_BLOCKSIZE; i++)
 	{
@@ -2374,5 +2338,55 @@ void MapBlock::deSerialize(std::istream &is, u8 version)
 	}
 }
 
+void MapBlock::serializeDiskExtra(std::ostream &os, u8 version)
+{
+	// Versions up from 9 have block objects.
+	if(version >= 9)
+	{
+		serializeObjects(os, version);
+	}
+	
+	// Versions up from 15 have static objects.
+	if(version >= 15)
+	{
+		m_static_objects.serialize(os);
+	}
+
+	// Timestamp
+	if(version >= 17)
+	{
+		writeU32(os, getTimestamp());
+	}
+}
+
+void MapBlock::deSerializeDiskExtra(std::istream &is, u8 version)
+{
+	/*
+		Versions up from 9 have block objects.
+	*/
+	if(version >= 9)
+	{
+		updateObjects(is, version, NULL, 0);
+	}
+
+	/*
+		Versions up from 15 have static objects.
+	*/
+	if(version >= 15)
+	{
+		m_static_objects.deSerialize(is);
+	}
+		
+	// Timestamp
+	if(version >= 17)
+	{
+		setTimestamp(readU32(is));
+	}
+	else
+	{
+		setTimestamp(BLOCK_TIMESTAMP_UNDEFINED);
+	}
+}
+
 
 //END
diff --git a/src/mapblock.h b/src/mapblock.h
index 30e9e38f8..1eb97353c 100644
--- a/src/mapblock.h
+++ b/src/mapblock.h
@@ -34,6 +34,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "nodemetadata.h"
 #include "staticobject.h"
 
+#define BLOCK_TIMESTAMP_UNDEFINED 0xffffffff
 
 // Named by looking towards z+
 enum{
@@ -244,24 +245,28 @@ public:
 		reallocate();
 	}
 	
-	bool getChangedFlag()
+	/*
+		This is called internally or externally after the block is
+		modified, so that the block is saved and possibly not deleted from
+		memory.
+	*/
+	void setChangedFlag()
 	{
-		return changed;
+		changed = true;
 	}
 	void resetChangedFlag()
 	{
 		changed = false;
 	}
-	void setChangedFlag()
+	bool getChangedFlag()
 	{
-		changed = true;
+		return changed;
 	}
 
 	bool getIsUnderground()
 	{
 		return is_underground;
 	}
-
 	void setIsUnderground(bool a_is_underground)
 	{
 		is_underground = a_is_underground;
@@ -359,6 +364,15 @@ public:
 		return getNode(p.X, p.Y, p.Z);
 	}
 	
+	MapNode getNodeNoEx(v3s16 p)
+	{
+		try{
+			return getNode(p.X, p.Y, p.Z);
+		}catch(InvalidPositionException &e){
+			return MapNode(CONTENT_IGNORE);
+		}
+	}
+	
 	void setNode(s16 x, s16 y, s16 z, MapNode & n)
 	{
 		if(data == NULL)
@@ -444,47 +458,19 @@ public:
 				face_dir);
 	}
 	
-#ifndef SERVER
-	// light = 0...255
-	/*static void makeFastFace(TileSpec tile, u8 light, v3f p,
-			v3s16 dir, v3f scale, v3f posRelative_f,
-			core::array<FastFace> &dest);*/
-	
-	/*TileSpec getNodeTile(MapNode mn, v3s16 p, v3s16 face_dir,
-			NodeModMap &temp_mods);*/
-	/*u8 getNodeContent(v3s16 p, MapNode mn,
-			NodeModMap &temp_mods);*/
-
-	/*
-		Generates the FastFaces of a node row. This has a
-		ridiculous amount of parameters because that way they
-		can be precalculated by the caller.
+#ifndef SERVER // Only on client
 
-		translate_dir: unit vector with only one of x, y or z
-		face_dir: unit vector with only one of x, y or z
-	*/
-	/*void updateFastFaceRow(
-			u32 daynight_ratio,
-			v3f posRelative_f,
-			v3s16 startpos,
-			u16 length,
-			v3s16 translate_dir,
-			v3f translate_dir_f,
-			v3s16 face_dir,
-			v3f face_dir_f,
-			core::array<FastFace> &dest,
-			NodeModMap &temp_mods);*/
-	
+#if 1
 	/*
 		Thread-safely updates the whole mesh of the mapblock.
+		NOTE: Prefer generating the mesh separately and then using
+		replaceMesh().
 	*/
-#if 1
 	void updateMesh(u32 daynight_ratio);
 #endif
-
+	// Replace the mesh with a new one
 	void replaceMesh(scene::SMesh *mesh_new);
-	
-#endif // !SERVER
+#endif
 	
 	// See comments in mapblock.cpp
 	bool propagateSunlight(core::map<v3s16, bool> & light_sources,
@@ -498,6 +484,7 @@ public:
 
 	/*
 		MapBlockObject stuff
+		DEPRECATED
 	*/
 	
 	void serializeObjects(std::ostream &os, u8 version)
@@ -545,13 +532,6 @@ public:
 	*/
 	void stepObjects(float dtime, bool server, u32 daynight_ratio);
 
-	/*void wrapObject(MapBlockObject *object)
-	{
-		m_objects.wrapObject(object);
-
-		setChangedFlag();
-	}*/
-
 	// origin is relative to block
 	void getObjects(v3f origin, f32 max_d,
 			core::array<DistanceSortedObject> &dest)
@@ -564,7 +544,7 @@ public:
 		return m_objects.getCount();
 	}
 
-#ifndef SERVER
+#ifndef SERVER // Only on client
 	/*
 		Methods for setting temporary modifications to nodes for
 		drawing
@@ -640,13 +620,29 @@ public:
 	s16 getGroundLevel(v2s16 p2d);
 
 	/*
+		Timestamp (see m_timestamp)
+		NOTE: BLOCK_TIMESTAMP_UNDEFINED=0xffffffff means there is no timestamp.
+	*/
+	void setTimestamp(u32 time)
+	{
+		m_timestamp = time;
+		setChangedFlag();
+	}
+	u32 getTimestamp()
+	{
+		return m_timestamp;
+	}
+
+	/*
 		Serialization
 	*/
 	
-	// Doesn't write version by itself
+	// These don't write or read version by itself
 	void serialize(std::ostream &os, u8 version);
-
 	void deSerialize(std::istream &is, u8 version);
+	// Used after the basic ones when writing on disk (serverside)
+	void serializeDiskExtra(std::ostream &os, u8 version);
+	void deSerializeDiskExtra(std::istream &is, u8 version);
 
 private:
 	/*
@@ -676,7 +672,7 @@ public:
 		Public member variables
 	*/
 
-#ifndef SERVER
+#ifndef SERVER // Only on client
 	scene::SMesh *mesh;
 	JMutex mesh_mutex;
 #endif
@@ -729,12 +725,9 @@ private:
 	// Whether day and night lighting differs
 	bool m_day_night_differs;
 	
-	// TODO: Remove this
+	// DEPRECATED
 	MapBlockObjectList m_objects;
 
-	// Object spawning stuff
-	//float m_spawn_timer;
-
 #ifndef SERVER // Only on client
 	/*
 		Set to true if the mesh has been ordered to be updated
@@ -748,6 +741,12 @@ private:
 	NodeModMap m_temp_mods;
 	JMutex m_temp_mods_mutex;
 #endif
+	
+	/*
+		When block is removed from active blocks, this is set to gametime.
+		Value BLOCK_TIMESTAMP_UNDEFINED=0xffffffff means there is no timestamp.
+	*/
+	u32 m_timestamp;
 };
 
 inline bool blockpos_over_limit(v3s16 p)
diff --git a/src/mapnode.h b/src/mapnode.h
index 9ab885386..5a1770230 100644
--- a/src/mapnode.h
+++ b/src/mapnode.h
@@ -148,6 +148,8 @@ struct ContentFeatures
 	bool light_propagates;
 	bool sunlight_propagates;
 	u8 solidness; // Used when choosing which face is drawn
+	// This is used for collision detection.
+	// Also for general solidness queries.
 	bool walkable;
 	bool pointable;
 	bool diggable;
diff --git a/src/serialization.h b/src/serialization.h
index c7cafc5d1..fad1388e0 100644
--- a/src/serialization.h
+++ b/src/serialization.h
@@ -26,53 +26,55 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "utility.h"
 
 /*
+	Map format serialization version
+	--------------------------------
+
+	For map data (blocks, nodes, sectors).
+	
 	NOTE: The goal is to increment this so that saved maps will be
 	      loadable by any version. Other compatibility is not
 		  maintained.
-	Serialization format versions (for raw map data (blocks, nodes, sectors)):
-	== Unsupported ==
+		  
 	0: original networked test with 1-byte nodes
 	1: update with 2-byte nodes
-	== Supported ==
 	2: lighting is transmitted in param
 	3: optional fetching of far blocks
 	4: block compression
 	5: sector objects NOTE: block compression was left accidentally out
 	6: failed attempt at switching block compression on again
 	7: block compression switched on again
-	8: (dev) server-initiated block transfers and all kinds of stuff
-	9: (dev) block objects
-	10: (dev) water pressure
-	11: (dev) zlib'd blocks, block flags
-	12: (dev) UnlimitedHeightmap now uses interpolated areas
-	13: (dev) Mapgen v2
-	14: (dev) NodeMetadata
-	15: (dev) StaticObjects
-	16: (dev) larger maximum size of node metadata, and compression
+	8: server-initiated block transfers and all kinds of stuff
+	9: block objects
+	10: water pressure
+	11: zlib'd blocks, block flags
+	12: UnlimitedHeightmap now uses interpolated areas
+	13: Mapgen v2
+	14: NodeMetadata
+	15: StaticObjects
+	16: larger maximum size of node metadata, and compression
+	17: MapBlocks contain timestamp
 */
 // This represents an uninitialized or invalid format
 #define SER_FMT_VER_INVALID 255
 // Highest supported serialization version
-#define SER_FMT_VER_HIGHEST 16
+#define SER_FMT_VER_HIGHEST 17
 // Lowest supported serialization version
 #define SER_FMT_VER_LOWEST 0
 
 #define ser_ver_supported(v) (v >= SER_FMT_VER_LOWEST && v <= SER_FMT_VER_HIGHEST)
 
+/*
+	Misc. serialization functions
+*/
+
 void compressZlib(SharedBuffer<u8> data, std::ostream &os);
 void compressZlib(const std::string &data, std::ostream &os);
 void decompressZlib(std::istream &is, std::ostream &os);
 
+// These choose between zlib and a self-made one according to version
 void compress(SharedBuffer<u8> data, std::ostream &os, u8 version);
 //void compress(const std::string &data, std::ostream &os, u8 version);
 void decompress(std::istream &is, std::ostream &os, u8 version);
 
-/*class Serializable
-{
-public:
-	void serialize(std::ostream &os, u8 version) = 0;
-	void deSerialize(std::istream &istr);
-};*/
-
 #endif
 
diff --git a/src/server.cpp b/src/server.cpp
index b5cb48a36..84f9a28e0 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -30,6 +30,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mineral.h"
 #include "config.h"
 #include "servercommand.h"
+#include "filesys.h"
 
 #define BLOCK_EMERGE_FLAG_FROMDISK (1<<0)
 
@@ -798,7 +799,7 @@ void RemoteClient::SendObjectData(
 			*/
 			if(stepped_blocks.find(p) == NULL)
 			{
-				block->stepObjects(dtime, true, server->getDayNightRatio());
+				block->stepObjects(dtime, true, server->m_env.getDayNightRatio());
 				stepped_blocks.insert(p, true);
 				block->setChangedFlag();
 			}
@@ -968,7 +969,6 @@ Server::Server(
 	m_con(PROTOCOL_ID, 512, CONNECTION_TIMEOUT, this),
 	m_thread(this),
 	m_emergethread(this),
-	m_time_of_day(9000),
 	m_time_counter(0),
 	m_time_of_day_send_timer(0),
 	m_uptime(0),
@@ -987,10 +987,19 @@ Server::Server(
 	m_con_mutex.Init();
 	m_step_dtime_mutex.Init();
 	m_step_dtime = 0.0;
-
+	
+	// Register us to receive map edit events
 	m_env.getMap().addEventReceiver(this);
 
+	// If file exists, load environment metadata
+	if(fs::PathExists(m_mapsavedir+"/env_meta.txt"))
+	{
+		dstream<<"Server: Loading environment metadata"<<std::endl;
+		m_env.loadMeta(m_mapsavedir);
+	}
+
 	// Load players
+	dstream<<"Server: Loading players"<<std::endl;
 	m_env.deSerializePlayers(m_mapsavedir);
 }
 
@@ -1032,6 +1041,12 @@ Server::~Server()
 	*/
 	dstream<<"Server: Saving players"<<std::endl;
 	m_env.serializePlayers(m_mapsavedir);
+
+	/*
+		Save environment metadata
+	*/
+	dstream<<"Server: Saving environment metadata"<<std::endl;
+	m_env.saveMeta(m_mapsavedir);
 	
 	/*
 		Stop threads
@@ -1136,14 +1151,17 @@ void Server::AsyncRunStep()
 	}
 	
 	/*
-		Update m_time_of_day
+		Update m_time_of_day and overall game time
 	*/
 	{
+		JMutexAutoLock envlock(m_env_mutex);
+
 		m_time_counter += dtime;
 		f32 speed = g_settings.getFloat("time_speed") * 24000./(24.*3600);
 		u32 units = (u32)(m_time_counter*speed);
 		m_time_counter -= (f32)units / speed;
-		m_time_of_day.set((m_time_of_day.get() + units) % 24000);
+		
+		m_env.setTimeOfDay((m_env.getTimeOfDay() + units) % 24000);
 		
 		//dstream<<"Server: m_time_of_day = "<<m_time_of_day.get()<<std::endl;
 
@@ -1167,7 +1185,7 @@ void Server::AsyncRunStep()
 				//Player *player = m_env.getPlayer(client->peer_id);
 				
 				SharedBuffer<u8> data = makePacket_TOCLIENT_TIME_OF_DAY(
-						m_time_of_day.get());
+						m_env.getTimeOfDay());
 				// Send as reliable
 				m_con.Send(client->peer_id, 0, data, true);
 			}
@@ -1654,6 +1672,9 @@ void Server::AsyncRunStep()
 
 				// Save players
 				m_env.serializePlayers(m_mapsavedir);
+				
+				// Save environment metadata
+				m_env.saveMeta(m_mapsavedir);
 			}
 		}
 	}
@@ -1900,7 +1921,7 @@ void Server::ProcessData(u8 *data, u32 datasize, u16 peer_id)
 		// Send time of day
 		{
 			SharedBuffer<u8> data = makePacket_TOCLIENT_TIME_OF_DAY(
-					m_time_of_day.get());
+					m_env.getTimeOfDay());
 			m_con.Send(peer->id, 0, data, true);
 		}
 		
diff --git a/src/server.h b/src/server.h
index 289f09618..54330856c 100644
--- a/src/server.h
+++ b/src/server.h
@@ -382,20 +382,21 @@ public:
 
 	core::list<PlayerInfo> getPlayerInfo();
 
-	u32 getDayNightRatio()
+	/*u32 getDayNightRatio()
 	{
 		return time_to_daynight_ratio(m_time_of_day.get());
-	}
-
+	}*/
+	
+	// Environment must be locked when called
 	void setTimeOfDay(u32 time)
 	{
-		m_time_of_day.set(time);
+		m_env.setTimeOfDay(time);
 		m_time_of_day_send_timer = 0;
 	}
 
 	bool getShutdownRequested()
 	{
-		return m_shutdown_requested.get();
+		return m_shutdown_requested;
 	}
 	
 	/*
@@ -416,7 +417,7 @@ public:
 
 	void requestShutdown(void)
 	{
-		m_shutdown_requested.set(true);
+		m_shutdown_requested = true;
 	}
 
 
@@ -426,7 +427,8 @@ public:
 
 private:
 
-	// Virtual methods from con::PeerHandler.
+	// con::PeerHandler implementation.
+	// These queue stuff to be processed by handlePeerChanges().
 	// As of now, these create and remove clients and players.
 	void peerAdded(con::Peer *peer);
 	void deletingPeer(con::Peer *peer, bool timeout);
@@ -459,7 +461,7 @@ private:
 	void sendAddNode(v3s16 p, MapNode n, u16 ignore_id=0,
 			core::list<u16> *far_players=NULL, float far_d_nodes=100);
 	
-	// Environment and Connection must be locked when  called
+	// Environment and Connection must be locked when called
 	void SendBlockNoLock(u16 peer_id, MapBlock *block, u8 ver);
 	
 	// Sends blocks to clients
@@ -483,22 +485,17 @@ private:
 		Call with env and con locked.
 	*/
 	Player *emergePlayer(const char *name, const char *password, u16 peer_id);
-
-	/*
-		Update water pressure.
-		This also adds suitable nodes to active_nodes.
-
-		environment has to be locked when calling.
-	*/
-	/*void UpdateBlockWaterPressure(MapBlock *block,
-			core::map<v3s16, MapBlock*> &modified_blocks);*/
 	
 	// Locks environment and connection by its own
 	struct PeerChange;
 	void handlePeerChange(PeerChange &c);
 	void handlePeerChanges();
+
+	/*
+		Variables
+	*/
 	
-	//float m_flowwater_timer;
+	// Some timers
 	float m_liquid_transform_timer;
 	float m_print_info_timer;
 	float m_objectdata_timer;
@@ -507,52 +504,83 @@ private:
 	
 	// NOTE: If connection and environment are both to be locked,
 	// environment shall be locked first.
-	JMutex m_env_mutex;
-	ServerEnvironment m_env;
 
-	JMutex m_con_mutex;
+	// Environment
+	ServerEnvironment m_env;
+	JMutex m_env_mutex;
+	
+	// Connection
 	con::Connection m_con;
-	core::map<u16, RemoteClient*> m_clients; // Behind the con mutex
-
+	JMutex m_con_mutex;
+	// Connected clients (behind the con mutex)
+	core::map<u16, RemoteClient*> m_clients;
+	
+	/*
+		Threads
+	*/
+	
+	// A buffer for time steps
+	// step() increments and AsyncRunStep() run by m_thread reads it.
 	float m_step_dtime;
 	JMutex m_step_dtime_mutex;
 
+	// The server mainly operates in this thread
 	ServerThread m_thread;
+	// This thread fetches and generates map
 	EmergeThread m_emergethread;
-
+	// Queue of block coordinates to be processed by the emerge thread
 	BlockEmergeQueue m_emerge_queue;
 	
-	// Nodes that are destinations of flowing liquid at the moment
-	//core::map<v3s16, u8> m_flow_active_nodes;
+	/*
+		Time related stuff
+	*/
 
 	// 0-23999
-	MutexedVariable<u32> m_time_of_day;
+	//MutexedVariable<u32> m_time_of_day;
 	// Used to buffer dtime for adding to m_time_of_day
 	float m_time_counter;
+	// Timer for sending time of day over network
 	float m_time_of_day_send_timer;
-	
+	// Uptime of server in seconds
 	MutexedVariable<double> m_uptime;
 	
+	/*
+		Peer change queue.
+		Queues stuff from peerAdded() and deletingPeer() to
+		handlePeerChanges()
+	*/
 	enum PeerChangeType
 	{
 		PEER_ADDED,
 		PEER_REMOVED
 	};
-
 	struct PeerChange
 	{
 		PeerChangeType type;
 		u16 peer_id;
 		bool timeout;
 	};
-	
 	Queue<PeerChange> m_peer_change_queue;
 
+	/*
+		Random stuff
+	*/
+
+	// Map directory
 	std::string m_mapsavedir;
 
-	MutexedVariable<bool> m_shutdown_requested;
+	bool m_shutdown_requested;
 	
 	/*
+		Map edit event queue. Automatically receives all map edits.
+		The constructor of this class registers us to receive them through
+		onMapEditEvent
+
+		NOTE: Should these be moved to actually be members of
+		ServerEnvironment?
+	*/
+
+	/*
 		Queue of map edits from the environment for sending to the clients
 		This is behind m_env_mutex
 	*/
diff --git a/src/serverobject.cpp b/src/serverobject.cpp
index aa36dad92..d31e9a31c 100644
--- a/src/serverobject.cpp
+++ b/src/serverobject.cpp
@@ -29,6 +29,7 @@ ServerActiveObject::ServerActiveObject(ServerEnvironment *env, u16 id, v3f pos):
 	ActiveObject(id),
 	m_known_by_count(0),
 	m_removed(false),
+	m_pending_deactivation(false),
 	m_static_exists(false),
 	m_static_block(1337,1337,1337),
 	m_env(env),
diff --git a/src/serverobject.h b/src/serverobject.h
index 71199475e..955969819 100644
--- a/src/serverobject.h
+++ b/src/serverobject.h
@@ -106,8 +106,13 @@ public:
 	*/
 	virtual u16 punch(const std::string &toolname){return 0;}
 	
-	// Number of players which know about this object
+	/*
+		Number of players which know about this object. Object won't be
+		deleted until this is 0 to keep the id preserved for the right
+		object.
+	*/
 	u16 m_known_by_count;
+
 	/*
 		- Whether this object is to be removed when nobody knows about
 		  it anymore.
@@ -120,6 +125,16 @@ public:
 	bool m_removed;
 	
 	/*
+		This is set to true when a block should be removed from the active
+		object list but couldn't be removed because the id has to be
+		reserved for some client.
+
+		The environment checks this periodically. If this is true and also
+		m_known_by_count is true, 
+	*/
+	bool m_pending_deactivation;
+	
+	/*
 		Whether the object's static data has been stored to a block
 	*/
 	bool m_static_exists;
diff --git a/src/utility.h b/src/utility.h
index 0df43a31b..f32dc3acf 100644
--- a/src/utility.h
+++ b/src/utility.h
@@ -221,6 +221,19 @@ inline u16 readU16(std::istream &is)
 	return readU16((u8*)buf);
 }
 
+inline void writeU32(std::ostream &os, u16 p)
+{
+	char buf[4];
+	writeU16((u8*)buf, p);
+	os.write(buf, 4);
+}
+inline u16 readU32(std::istream &is)
+{
+	char buf[4];
+	is.read(buf, 4);
+	return readU32((u8*)buf);
+}
+
 inline void writeF1000(std::ostream &os, f32 p)
 {
 	char buf[2];