commit before some radicallish changes to water behavior

14 files changed, 1420 insertions, 166 deletions

diff --git a/src/exceptions.h b/src/exceptions.h
index 80bdbeb36..0f95bd07a 100644
--- a/src/exceptions.h
+++ b/src/exceptions.h
@@ -116,6 +116,14 @@ public:
 	{}
 };
 
+class ProcessingLimitException : public BaseException
+{
+public:
+	ProcessingLimitException(const char *s):
+		BaseException(s)
+	{}
+};
+
 /*
 	Some "old-style" interrupts:
 */
diff --git a/src/main.cpp b/src/main.cpp
index 938eb14ef..73ef37951 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -173,9 +173,12 @@ TODO: Remove LazyMeshUpdater. It is not used as supposed.
 FIXME: Rats somehow go underground sometimes (you can see it in water)

        - Does their position get saved to a border value or something?

 

-TODO: MovingObject::move and Player::move are basically the same.

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

       combine them.

 

+TODO: Transfer sign texts as metadata of block and not as data of

+      object

+

 Doing now:

 ======================================================================

 

diff --git a/src/map.cpp b/src/map.cpp
index 050299bc9..88cb0f3f7 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -47,10 +47,10 @@ MapBlockPointerCache::~MapBlockPointerCache()
 {
 	m_map->m_blockcachelock.cacheRemoved();
 
-	dstream<<"MapBlockPointerCache:"
+	/*dstream<<"MapBlockPointerCache:"
 			<<" from_cache_count="<<m_from_cache_count
 			<<" from_map_count="<<m_from_map_count
-			<<std::endl;
+			<<std::endl;*/
 }
 
 MapBlock * MapBlockPointerCache::getBlockNoCreate(v3s16 p)
@@ -1050,6 +1050,8 @@ void Map::removeNodeAndUpdate(v3s16 p,
 	// Node will be replaced with this
 	u8 replace_material = MATERIAL_AIR;
 	
+	// NOTE: Water is now managed elsewhere
+#if 0
 	{
 		/*
 			Find out with what material the node will be replaced.
@@ -1107,6 +1109,8 @@ void Map::removeNodeAndUpdate(v3s16 p,
 		}
 	}
 
+#endif
+
 	/*
 		If there is a node at top and it doesn't have sunlight,
 		there will be no sunlight going down.
@@ -3143,3 +3147,144 @@ void ClientMap::PrintInfo(std::ostream &out)
 }
 
 
+/*
+	MapVoxelManipulator
+*/
+
+MapVoxelManipulator::MapVoxelManipulator(Map *map)
+{
+	m_map = map;
+}
+
+MapVoxelManipulator::~MapVoxelManipulator()
+{
+	dstream<<"MapVoxelManipulator: blocks: "<<m_loaded_blocks.size()
+			<<std::endl;
+}
+
+void MapVoxelManipulator::emerge(VoxelArea a)
+{
+	TimeTaker timer1("emerge", g_device, &emerge_time);
+
+	// Units of these are MapBlocks
+	v3s16 p_min = getNodeBlockPos(a.MinEdge);
+	v3s16 p_max = getNodeBlockPos(a.MaxEdge);
+
+	VoxelArea block_area_nodes
+			(p_min*MAP_BLOCKSIZE, (p_max+1)*MAP_BLOCKSIZE-v3s16(1,1,1));
+
+	addArea(block_area_nodes);
+
+	for(s32 z=p_min.Z; z<=p_max.Z; z++)
+	for(s32 y=p_min.Y; y<=p_max.Y; y++)
+	for(s32 x=p_min.X; x<=p_max.X; x++)
+	{
+		v3s16 p(x,y,z);
+		core::map<v3s16, bool>::Node *n;
+		n = m_loaded_blocks.find(p);
+		if(n != NULL)
+			continue;
+		
+		bool block_data_inexistent = false;
+		try
+		{
+			TimeTaker timer1("emerge load", g_device, &emerge_load_time);
+
+			dstream<<"Loading block ("<<p.X<<","<<p.Y<<","<<p.Z<<")"
+					<<std::endl;
+			
+			MapBlock *block = m_map->getBlockNoCreate(p);
+			if(block->isDummy())
+				block_data_inexistent = true;
+			else
+				block->copyTo(*this);
+		}
+		catch(InvalidPositionException &e)
+		{
+			block_data_inexistent = true;
+		}
+
+		if(block_data_inexistent)
+		{
+			VoxelArea a(p*MAP_BLOCKSIZE, (p+1)*MAP_BLOCKSIZE-v3s16(1,1,1));
+			// Fill with VOXELFLAG_INEXISTENT
+			for(s32 z=a.MinEdge.Z; z<=a.MaxEdge.Z; z++)
+			for(s32 y=a.MinEdge.Y; y<=a.MaxEdge.Y; y++)
+			{
+				s32 i = m_area.index(a.MinEdge.X,y,z);
+				memset(&m_flags[i], VOXELFLAG_INEXISTENT, MAP_BLOCKSIZE);
+			}
+		}
+
+		m_loaded_blocks.insert(p, true);
+	}
+
+	//dstream<<"emerge done"<<std::endl;
+}
+
+/*
+	TODO: Add an option to only update eg. water and air nodes.
+	      This will make it interfere less with important stuff if
+		  run on background.
+*/
+void MapVoxelManipulator::blitBack
+		(core::map<v3s16, MapBlock*> & modified_blocks)
+{
+	TimeTaker timer1("blitBack", g_device);
+	
+	/*
+		Initialize block cache
+	*/
+	v3s16 blockpos_last;
+	MapBlock *block = NULL;
+	bool block_checked_in_modified = false;
+
+	for(s32 z=m_area.MinEdge.Z; z<=m_area.MaxEdge.Z; z++)
+	for(s32 y=m_area.MinEdge.Y; y<=m_area.MaxEdge.Y; y++)
+	for(s32 x=m_area.MinEdge.X; x<=m_area.MaxEdge.X; x++)
+	{
+		v3s16 p(x,y,z);
+
+		u8 f = m_flags[m_area.index(p)];
+		if(f & (VOXELFLAG_NOT_LOADED|VOXELFLAG_INEXISTENT))
+			continue;
+
+		MapNode &n = m_data[m_area.index(p)];
+			
+		v3s16 blockpos = getNodeBlockPos(p);
+		
+		try
+		{
+			// Get block
+			if(block == NULL || blockpos != blockpos_last){
+				block = m_map->getBlockNoCreate(blockpos);
+				blockpos_last = blockpos;
+				block_checked_in_modified = false;
+			}
+			
+			// Calculate relative position in block
+			v3s16 relpos = p - blockpos * MAP_BLOCKSIZE;
+
+			// Don't continue if nothing has changed here
+			if(block->getNode(relpos) == n)
+				continue;
+
+			//m_map->setNode(m_area.MinEdge + p, n);
+			block->setNode(relpos, n);
+			
+			/*
+				Make sure block is in modified_blocks
+			*/
+			if(block_checked_in_modified == false)
+			{
+				modified_blocks[blockpos] = block;
+				block_checked_in_modified = true;
+			}
+		}
+		catch(InvalidPositionException &e)
+		{
+		}
+	}
+}
+
+//END
diff --git a/src/map.h b/src/map.h
index 7f791ffad..62d1f8aee 100644
--- a/src/map.h
+++ b/src/map.h
@@ -40,6 +40,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapblock.h"
 #include "mapsector.h"
 #include "constants.h"
+#include "voxel.h"
 
 class Map;
 
@@ -49,6 +50,7 @@ class Map;
 	NOTE: This doesn't really make anything more efficient
 	NOTE: Use VoxelManipulator, if possible
 	TODO: Get rid of this?
+	NOTE: CONFIRMED: THIS CACHE DOESN'T MAKE ANYTHING ANY FASTER
 */
 class MapBlockPointerCache : public NodeContainer
 {
@@ -121,7 +123,7 @@ public:
 
 	void cacheCreated()
 	{
-		dstream<<"cacheCreated() begin"<<std::endl;
+		//dstream<<"cacheCreated() begin"<<std::endl;
 		JMutexAutoLock waitcachelock(m_waitcache_mutex);
 		JMutexAutoLock countlock(m_count_mutex);
 
@@ -131,12 +133,12 @@ public:
 			
 		m_count++;
 
-		dstream<<"cacheCreated() end"<<std::endl;
+		//dstream<<"cacheCreated() end"<<std::endl;
 	}
 
 	void cacheRemoved()
 	{
-		dstream<<"cacheRemoved() begin"<<std::endl;
+		//dstream<<"cacheRemoved() begin"<<std::endl;
 		JMutexAutoLock countlock(m_count_mutex);
 
 		assert(m_count > 0);
@@ -147,7 +149,7 @@ public:
 		if(m_count == 0)
 			m_cache_mutex.Unlock();
 
-		dstream<<"cacheRemoved() end"<<std::endl;
+		//dstream<<"cacheRemoved() end"<<std::endl;
 	}
 
 	/*
@@ -589,5 +591,29 @@ private:
 	JMutex mesh_mutex;
 };
 
+class MapVoxelManipulator : public VoxelManipulator
+{
+public:
+	MapVoxelManipulator(Map *map);
+	virtual ~MapVoxelManipulator();
+	
+	virtual void clear()
+	{
+		VoxelManipulator::clear();
+		m_loaded_blocks.clear();
+	}
+
+	virtual void emerge(VoxelArea a);
+
+	void blitBack(core::map<v3s16, MapBlock*> & modified_blocks);
+
+private:
+	Map *m_map;
+	// bool is dummy value
+	// SUGG: How 'bout an another VoxelManipulator for storing the
+	//       information about which block is loaded?
+	core::map<v3s16, bool> m_loaded_blocks;
+};
+
 #endif
 
diff --git a/src/mapblock.cpp b/src/mapblock.cpp
index a4da657d1..d2c323291 100644
--- a/src/mapblock.cpp
+++ b/src/mapblock.cpp
@@ -696,6 +696,15 @@ bool MapBlock::propagateSunlight(core::map<v3s16, bool> & light_sources)
 	return block_below_is_valid;
 }
 
+void MapBlock::copyTo(VoxelManipulator &dst)
+{
+	v3s16 data_size(MAP_BLOCKSIZE, MAP_BLOCKSIZE, MAP_BLOCKSIZE);
+	VoxelArea data_area(v3s16(0,0,0), data_size - v3s16(1,1,1));
+	
+	dst.copyFrom(data, data_area, v3s16(0,0,0),
+			getPosRelative(), data_size);
+}
+
 /*
 	Serialization
 */
@@ -755,6 +764,17 @@ void MapBlock::serialize(std::ostream &os, u8 version)
 			paramdata[i] = data[i].param;
 		}
 		compress(paramdata, os, version);
+		
+		if(version >= 10)
+		{
+			// Get and compress pressure
+			SharedBuffer<u8> pressuredata(nodecount);
+			for(u32 i=0; i<nodecount; i++)
+			{
+				pressuredata[i] = data[i].pressure;
+			}
+			compress(pressuredata, os, version);
+		}
 	}
 }
 
@@ -819,6 +839,21 @@ void MapBlock::deSerialize(std::istream &is, u8 version)
 				data[i].param = s[i];
 			}
 		}
+	
+		if(version >= 10)
+		{
+			// Uncompress and set pressure data
+			std::ostringstream os(std::ios_base::binary);
+			decompress(is, os, version);
+			std::string s = os.str();
+			if(s.size() != nodecount)
+				throw SerializationError
+						("MapBlock::deSerialize: invalid format");
+			for(u32 i=0; i<s.size(); i++)
+			{
+				data[i].pressure = s[i];
+			}
+		}
 	}
 }
 
diff --git a/src/mapblock.h b/src/mapblock.h
index 2c04343de..c18bbb2b4 100644
--- a/src/mapblock.h
+++ b/src/mapblock.h
@@ -30,6 +30,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "serialization.h"
 #include "constants.h"
 #include "mapblockobject.h"
+#include "voxel.h"
 
 #define MAP_BLOCKSIZE 16
 
@@ -69,31 +70,6 @@ public:
 
 class MapBlock : public NodeContainer
 {
-private:
-
-	NodeContainer *m_parent;
-	// Position in blocks on parent
-	v3s16 m_pos;
-	/*
-		If NULL, block is a dummy block.
-		Dummy blocks are used for caching not-found-on-disk blocks.
-	*/
-	MapNode * data;
-	/*
-		- On the client, this is used for checking whether to
-		  recalculate the face cache. (Is it anymore?)
-		- On the server, this is used for telling whether the
-		  block has been changed from the one on disk.
-	*/
-	bool changed;
-	/*
-		Used for some initial lighting stuff.
-		At least /has been/ used. 8)
-	*/
-	bool is_underground;
-	
-	MapBlockObjectList m_objects;
-	
 public:
 
 	/*
@@ -333,10 +309,12 @@ public:
 
 	bool propagateSunlight(core::map<v3s16, bool> & light_sources);
 	
-	// Doesn't write version by itself
-	void serialize(std::ostream &os, u8 version);
+	// Copies data to VoxelManipulator to getPosRelative()
+	void copyTo(VoxelManipulator &dst);
 
-	void deSerialize(std::istream &is, u8 version);
+	/*
+		Object stuff
+	*/
 	
 	void serializeObjects(std::ostream &os, u8 version)
 	{
@@ -403,6 +381,15 @@ public:
 		return m_objects.getCount();
 	}
 
+	/*
+		Serialization
+	*/
+	
+	// Doesn't write version by itself
+	void serialize(std::ostream &os, u8 version);
+
+	void deSerialize(std::istream &is, u8 version);
+
 private:
 
 	/*
@@ -420,6 +407,31 @@ private:
 	{
 		return getNodeRef(p.X, p.Y, p.Z);
 	}
+
+	
+	NodeContainer *m_parent;
+	// Position in blocks on parent
+	v3s16 m_pos;
+	/*
+		If NULL, block is a dummy block.
+		Dummy blocks are used for caching not-found-on-disk blocks.
+	*/
+	MapNode * data;
+	/*
+		- On the client, this is used for checking whether to
+		  recalculate the face cache. (Is it anymore?)
+		- On the server, this is used for telling whether the
+		  block has been changed from the one on disk.
+	*/
+	bool changed;
+	/*
+		Used for some initial lighting stuff.
+		At least /has been/ used. 8)
+	*/
+	bool is_underground;
+	
+	MapBlockObjectList m_objects;
+	
 };
 
 inline bool blockpos_over_limit(v3s16 p)
diff --git a/src/mapnode.h b/src/mapnode.h
index 02abe4e52..7502c42d7 100644
--- a/src/mapnode.h
+++ b/src/mapnode.h
@@ -205,10 +205,11 @@ struct MapNode
 		*this = n;
 	}
 	
-	MapNode(u8 data=MATERIAL_AIR, u8 a_param=0)
+	MapNode(u8 data=MATERIAL_AIR, u8 a_param=0, u8 a_pressure=0)
 	{
 		d = data;
 		param = a_param;
+		pressure = a_pressure;
 	}
 
 	bool operator==(const MapNode &other)
@@ -261,6 +262,11 @@ struct MapNode
 		param = a_light;
 	}
 
+	/*
+		These serialization functions are used when informing client
+		of a single node add
+	*/
+
 	static u32 serializedLength(u8 version)
 	{
 		if(!ser_ver_supported(version))
@@ -268,8 +274,10 @@ struct MapNode
 			
 		if(version == 0)
 			return 1;
-		else
+		else if(version <= 9)
 			return 2;
+		else
+			return 3;
 	}
 	void serialize(u8 *dest, u8 version)
 	{
@@ -280,10 +288,16 @@ struct MapNode
 		{
 			dest[0] = d;
 		}
+		else if(version <= 9)
+		{
+			dest[0] = d;
+			dest[1] = param;
+		}
 		else
 		{
 			dest[0] = d;
 			dest[1] = param;
+			dest[2] = pressure;
 		}
 	}
 	void deSerialize(u8 *source, u8 version)
@@ -304,10 +318,16 @@ struct MapNode
 			else
 				param = source[1];
 		}
+		else if(version <= 9)
+		{
+			d = source[0];
+			param = source[1];
+		}
 		else
 		{
 			d = source[0];
 			param = source[1];
+			pressure = source[2];
 		}
 	}
 };
diff --git a/src/serialization.h b/src/serialization.h
index 6e18497cf..8d3c5fee2 100644
--- a/src/serialization.h
+++ b/src/serialization.h
@@ -46,11 +46,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	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
 */
 // This represents an uninitialized or invalid format
 #define SER_FMT_VER_INVALID 255
 // Highest supported serialization version
-#define SER_FMT_VER_HIGHEST 9
+#define SER_FMT_VER_HIGHEST 10
 // Lowest supported serialization version
 #define SER_FMT_VER_LOWEST 2
 
diff --git a/src/server.cpp b/src/server.cpp
index f8248acb4..8bcfe5216 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -29,6 +29,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "jmutexautolock.h"
 #include "main.h"
 #include "constants.h"
+#include "voxel.h"
 
 void * ServerThread::Thread()
 {
@@ -990,6 +991,76 @@ void Server::AsyncRunStep()
 	/*
 		Do background stuff
 	*/
+
+	/*
+		Flow water
+	*/
+	{
+		static float counter = 0.0;
+		counter += dtime;
+		if(counter >= 1.0)
+		{
+		
+		counter = 0.0;
+
+		core::map<v3s16, MapBlock*> modified_blocks;
+
+		{
+
+			JMutexAutoLock lock(m_env_mutex);
+			
+			MapVoxelManipulator v(&m_env.getMap());
+			
+			/*try{
+				v.flowWater(m_flow_active_nodes, 0, false, 20);
+				//v.flowWater(p_under, 0, true, 100);
+			}
+			catch(ProcessingLimitException &e)
+			{
+				dstream<<"Processing limit reached"<<std::endl;
+			}*/
+
+			v.flowWater(m_flow_active_nodes, 0, false, 20);
+
+			v.blitBack(modified_blocks);
+
+			ServerMap &map = ((ServerMap&)m_env.getMap());
+			
+			// Update lighting
+			core::map<v3s16, MapBlock*> lighting_modified_blocks;
+			map.updateLighting(modified_blocks, lighting_modified_blocks);
+			
+			// Add blocks modified by lighting to modified_blocks
+			for(core::map<v3s16, MapBlock*>::Iterator
+					i = lighting_modified_blocks.getIterator();
+					i.atEnd() == false; i++)
+			{
+				MapBlock *block = i.getNode()->getValue();
+				modified_blocks.insert(block->getPos(), block);
+			}
+		}
+
+		/*
+			Set the modified blocks unsent for all the clients
+		*/
+		
+		JMutexAutoLock lock2(m_con_mutex);
+
+		for(core::map<u16, RemoteClient*>::Iterator
+				i = m_clients.getIterator();
+				i.atEnd() == false; i++)
+		{
+			RemoteClient *client = i.getNode()->getValue();
+			
+			if(modified_blocks.size() > 0)
+			{
+				// Remove block from sent history
+				client->SetBlocksNotSent(modified_blocks);
+			}
+		}
+
+		}
+	}
 	
 	// Periodically print some info
 	{
@@ -1458,6 +1529,31 @@ void Server::ProcessData(u8 *data, u32 datasize, u16 peer_id)
 				(this takes some time so it is done after the quick stuff)
 			*/
 			m_env.getMap().removeNodeAndUpdate(p_under, modified_blocks);
+			
+			/*
+				Update water
+			*/
+			
+			// Update water pressure around modification
+			// This also adds it to m_flow_active_nodes if appropriate
+
+			MapVoxelManipulator v(&m_env.getMap());
+			
+			VoxelArea area(p_under-v3s16(1,1,1), p_under+v3s16(1,1,1));
+
+			try
+			{
+				v.updateAreaWaterPressure(area, m_flow_active_nodes);
+			}
+			catch(ProcessingLimitException &e)
+			{
+				dstream<<"Processing limit reached"<<std::endl;
+			}
+			
+			v.blitBack(modified_blocks);
+			
+			// Add the node to m_flow_active_nodes.
+			//m_flow_active_nodes[p_under] = 1;
 
 		} // button == 0
 		/*
diff --git a/src/server.h b/src/server.h
index a48f88805..82e9136b5 100644
--- a/src/server.h
+++ b/src/server.h
@@ -469,6 +469,9 @@ private:
 
 	BlockEmergeQueue m_emerge_queue;
 	
+	// Nodes that are destinations of flowing liquid at the moment
+	core::map<v3s16, u8> m_flow_active_nodes;
+	
 	friend class EmergeThread;
 	friend class RemoteClient;
 };
diff --git a/src/test.cpp b/src/test.cpp
index 6b285e3a4..ebefb8e32 100644
--- a/src/test.cpp
+++ b/src/test.cpp
@@ -148,10 +148,45 @@ struct TestVoxelManipulator
 {
 	void Run()
 	{
+		/*
+			VoxelArea
+		*/
+
 		VoxelArea a(v3s16(-1,-1,-1), v3s16(1,1,1));
 		assert(a.index(0,0,0) == 1*3*3 + 1*3 + 1);
 		assert(a.index(-1,-1,-1) == 0);
+		
+		VoxelArea c(v3s16(-2,-2,-2), v3s16(2,2,2));
+		// An area that is 1 bigger in x+ and z-
+		VoxelArea d(v3s16(-2,-2,-3), v3s16(3,2,2));
+		
+		core::list<VoxelArea> aa;
+		d.diff(c, aa);
+		
+		// Correct results
+		core::array<VoxelArea> results;
+		results.push_back(VoxelArea(v3s16(-2,-2,-3),v3s16(3,2,-3)));
+		results.push_back(VoxelArea(v3s16(3,-2,-2),v3s16(3,2,2)));
+
+		assert(aa.size() == results.size());
+		
+		dstream<<"Result of diff:"<<std::endl;
+		for(core::list<VoxelArea>::Iterator
+				i = aa.begin(); i != aa.end(); i++)
+		{
+			i->print(dstream);
+			dstream<<std::endl;
+			
+			s32 j = results.linear_search(*i);
+			assert(j != -1);
+			results.erase(j, 1);
+		}
+
 
+		/*
+			VoxelManipulator
+		*/
+		
 		VoxelManipulator v;
 
 		v.print(dstream);
@@ -186,18 +221,19 @@ struct TestVoxelManipulator
 		v.clear();
 
 		const char *content =
-			"#...######"
-			"#...##..##"
-			"#........ "
-			"##########"
-
-			"#...######"
-			"#...##..##"
-			"#........ "
-			"##########"
+			"#...######  "
+			"#...##..##  "
+			"#........ .."
+			"############"
+
+			"#...######  "
+			"#...##..##  "
+			"#........#  "
+			"############"
 		;
 
-		v3s16 size(10, 4, 2);
+		v3s16 size(12, 4, 2);
+		VoxelArea area(v3s16(0,0,0), size-v3s16(1,1,1));
 		
 		const char *p = content;
 		for(s16 z=0; z<size.Z; z++)
@@ -205,7 +241,7 @@ struct TestVoxelManipulator
 		for(s16 x=0; x<size.X; x++)
 		{
 			MapNode n;
-			n.pressure = size.Y - y;
+			//n.pressure = size.Y - y;
 			if(*p == '#')
 				n.d = MATERIAL_STONE;
 			else if(*p == '.')
@@ -218,7 +254,24 @@ struct TestVoxelManipulator
 			p++;
 		}
 
-		v.print(dstream);
+		v.print(dstream, VOXELPRINT_WATERPRESSURE);
+		
+		core::map<v3s16, u8> active_nodes;
+		v.updateAreaWaterPressure(area, active_nodes);
+
+		v.print(dstream, VOXELPRINT_WATERPRESSURE);
+		
+		s16 highest_y = -32768;
+		assert(v.getWaterPressure(v3s16(7, 1, 1), highest_y, 0) == -1);
+		assert(highest_y == 3);
+		
+		active_nodes.clear();
+		active_nodes[v3s16(9,1,0)] = 1;
+		//v.flowWater(active_nodes, 0, false);
+		v.flowWater(active_nodes, 0, true);
+		
+		dstream<<"Final result of flowWater:"<<std::endl;
+		v.print(dstream, VOXELPRINT_WATERPRESSURE);
 		
 		//assert(0);
 	}
diff --git a/src/utility.h b/src/utility.h
index 93fd9d4a7..c9b13546c 100644
--- a/src/utility.h
+++ b/src/utility.h
@@ -394,12 +394,18 @@ private:
 class TimeTaker
 {
 public:
-	TimeTaker(const char *name, IrrlichtDevice *dev)
+	TimeTaker(const char *name, IrrlichtDevice *dev, u32 *result=NULL)
 	{
 		m_name = name;
 		m_dev = dev;
-		m_time1 = m_dev->getTimer()->getRealTime();
+		m_result = result;
 		m_running = true;
+		if(dev == NULL)
+		{
+			m_time1 = 0;
+			return;
+		}
+		m_time1 = m_dev->getTimer()->getRealTime();
 	}
 	~TimeTaker()
 	{
@@ -409,10 +415,24 @@ public:
 	{
 		if(m_running)
 		{
+			if(m_dev == NULL)
+			{
+				/*if(quiet == false)
+					std::cout<<"Couldn't measure time for "<<m_name
+							<<": dev==NULL"<<std::endl;*/
+				return 0;
+			}
 			u32 time2 = m_dev->getTimer()->getRealTime();
 			u32 dtime = time2 - m_time1;
-			if(quiet == false)
-				std::cout<<m_name<<" took "<<dtime<<"ms"<<std::endl;
+			if(m_result != NULL)
+			{
+				(*m_result) += dtime;
+			}
+			else
+			{
+				if(quiet == false)
+					std::cout<<m_name<<" took "<<dtime<<"ms"<<std::endl;
+			}
 			m_running = false;
 			return dtime;
 		}
@@ -423,6 +443,7 @@ private:
 	IrrlichtDevice *m_dev;
 	u32 m_time1;
 	bool m_running;
+	u32 *m_result;
 };
 
 // Calculates the borders of a "d-radius" cube
diff --git a/src/voxel.cpp b/src/voxel.cpp
index fe176a27a..15624feed 100644
--- a/src/voxel.cpp
+++ b/src/voxel.cpp
@@ -20,6 +20,23 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "voxel.h"
 #include "map.h"
 
+// For TimeTaker
+#include "main.h"
+#include "utility.h"
+
+/*
+	Debug stuff
+*/
+u32 addarea_time = 0;
+u32 emerge_time = 0;
+u32 emerge_load_time = 0;
+u32 clearflag_time = 0;
+//u32 getwaterpressure_time = 0;
+//u32 spreadwaterpressure_time = 0;
+u32 updateareawaterpressure_time = 0;
+u32 flowwater_pre_time = 0;
+
+
 VoxelManipulator::VoxelManipulator():
 	m_data(NULL),
 	m_flags(NULL)
@@ -47,7 +64,7 @@ void VoxelManipulator::clear()
 	m_flags = NULL;
 }
 
-void VoxelManipulator::print(std::ostream &o)
+void VoxelManipulator::print(std::ostream &o, VoxelPrintMode mode)
 {
 	v3s16 em = m_area.getExtent();
 	v3s16 of = m_area.MinEdge;
@@ -78,8 +95,29 @@ void VoxelManipulator::print(std::ostream &o)
 				{
 					c = 'X';
 					u8 m = m_data[m_area.index(x,y,z)].d;
-					if(m <= 9)
-						c = m + '0';
+					u8 pr = m_data[m_area.index(x,y,z)].pressure;
+					if(mode == VOXELPRINT_MATERIAL)
+					{
+						if(m <= 9)
+							c = m + '0';
+					}
+					else if(mode == VOXELPRINT_WATERPRESSURE)
+					{
+						if(m == MATERIAL_WATER)
+						{
+							c = 'w';
+							if(pr <= 9)
+								c = pr + '0';
+						}
+						else if(m == MATERIAL_AIR)
+						{
+							c = ' ';
+						}
+						else
+						{
+							c = '#';
+						}
+					}
 				}
 				o<<c;
 			}
@@ -99,6 +137,8 @@ void VoxelManipulator::addArea(VoxelArea area)
 	if(m_area.contains(area))
 		return;
 	
+	TimeTaker timer("addArea", g_device, &addarea_time);
+
 	// Calculate new area
 	VoxelArea new_area;
 	// New area is the requested area if m_area has zero volume
@@ -163,6 +203,21 @@ void VoxelManipulator::addArea(VoxelArea area)
 		delete[] old_data;
 	if(old_flags)
 		delete[] old_flags;
+
+	//dstream<<"addArea done"<<std::endl;
+}
+
+void VoxelManipulator::copyFrom(MapNode *src, VoxelArea src_area,
+		v3s16 from_pos, v3s16 to_pos, v3s16 size)
+{
+	for(s16 z=0; z<size.Z; z++)
+	for(s16 y=0; y<size.Y; y++)
+	{
+		s32 i_src = src_area.index(from_pos.X, from_pos.Y+y, from_pos.Z+z);
+		s32 i_local = m_area.index(to_pos.X, to_pos.Y+y, to_pos.Z+z);
+		memcpy(&m_data[i_local], &src[i_src], size.X*sizeof(MapNode));
+		memset(&m_flags[i_local], 0, size.X);
+	}
 }
 
 void VoxelManipulator::interpolate(VoxelArea area)
@@ -230,7 +285,318 @@ void VoxelManipulator::interpolate(VoxelArea area)
 	}
 }
 
-void VoxelManipulator::flowWater(v3s16 removed_pos)
+
+void VoxelManipulator::clearFlag(u8 flags)
+{
+	// 0-1ms on moderate area
+	TimeTaker timer("clearFlag", g_device, &clearflag_time);
+
+	v3s16 s = m_area.getExtent();
+
+	/*dstream<<"clearFlag clearing area of size "
+			<<""<<s.X<<"x"<<s.Y<<"x"<<s.Z<<""
+			<<std::endl;*/
+
+	//s32 count = 0;
+
+	/*for(s32 z=m_area.MinEdge.Z; z<=m_area.MaxEdge.Z; z++)
+	for(s32 y=m_area.MinEdge.Y; y<=m_area.MaxEdge.Y; y++)
+	for(s32 x=m_area.MinEdge.X; x<=m_area.MaxEdge.X; x++)
+	{
+		u8 f = m_flags[m_area.index(x,y,z)];
+		m_flags[m_area.index(x,y,z)] &= ~flags;
+		if(m_flags[m_area.index(x,y,z)] != f)
+			count++;
+	}*/
+
+	s32 volume = m_area.getVolume();
+	for(s32 i=0; i<volume; i++)
+	{
+		m_flags[i] &= ~flags;
+	}
+
+	/*s32 volume = m_area.getVolume();
+	for(s32 i=0; i<volume; i++)
+	{
+		u8 f = m_flags[i];
+		m_flags[i] &= ~flags;
+		if(m_flags[i] != f)
+			count++;
+	}
+
+	dstream<<"clearFlag changed "<<count<<" flags out of "
+			<<volume<<" nodes"<<std::endl;*/
+}
+
+int VoxelManipulator::getWaterPressure(v3s16 p, s16 &highest_y, int recur_count)
+{
+	m_flags[m_area.index(p)] |= VOXELFLAG_CHECKED2;
+
+	if(p.Y > highest_y)
+		highest_y = p.Y;
+	
+	recur_count++;
+	if(recur_count > 30)
+		throw ProcessingLimitException
+				("getWaterPressure recur_count limit reached");
+
+	v3s16 dirs[6] = {
+		v3s16(0,1,0), // top
+		v3s16(-1,0,0), // left
+		v3s16(1,0,0), // right
+		v3s16(0,0,-1), // front
+		v3s16(0,0,1), // back
+		v3s16(0,-1,0), // bottom
+	};
+
+	// Load neighboring nodes
+	// TODO: A bigger area would be better
+	emerge(VoxelArea(p - v3s16(1,1,1), p + v3s16(1,1,1)));
+
+	s32 i;
+	for(i=0; i<6; i++)
+	{
+		v3s16 p2 = p + dirs[i];
+		u8 f = m_flags[m_area.index(p2)];
+		// Ignore inexistent or checked nodes
+		if(f & (VOXELFLAG_INEXISTENT | VOXELFLAG_CHECKED2))
+			continue;
+		MapNode &n = m_data[m_area.index(p2)];
+		// Ignore non-liquid nodes
+		if(material_liquid(n.d) == false)
+			continue;
+
+		int pr;
+		
+		// If at surface
+		/*if(n.pressure == 1)
+		{
+			pr = 1;
+		}
+		// Otherwise recurse more
+		else*/
+		{
+			pr = getWaterPressure(p2, highest_y, recur_count);
+			if(pr == -1)
+				continue;
+		}
+
+		// If block is at top, pressure here is one higher
+		if(i == 0)
+		{
+			if(pr < 255)
+				pr++;
+		}
+		// If block is at bottom, pressure here is one lower
+		else if(i == 5)
+		{
+			if(pr > 1)
+				pr--;
+		}
+		
+		// Node is on the pressure route
+		m_flags[m_area.index(p)] |= VOXELFLAG_CHECKED4;
+
+		// Got pressure
+		return pr;
+	}
+	
+	// Nothing useful found
+	return -1;
+}
+
+void VoxelManipulator::spreadWaterPressure(v3s16 p, int pr,
+		VoxelArea request_area,
+		core::map<v3s16, u8> &active_nodes,
+		int recur_count)
+{
+	recur_count++;
+	if(recur_count > 10000)
+		throw ProcessingLimitException
+				("spreadWaterPressure recur_count limit reached");
+
+	m_flags[m_area.index(p)] |= VOXELFLAG_CHECKED3;
+	m_data[m_area.index(p)].pressure = pr;
+
+	v3s16 dirs[6] = {
+		v3s16(0,1,0), // top
+		v3s16(-1,0,0), // left
+		v3s16(1,0,0), // right
+		v3s16(0,0,-1), // front
+		v3s16(0,0,1), // back
+		v3s16(0,-1,0), // bottom
+	};
+
+	// Load neighboring nodes
+	emerge(VoxelArea(p - v3s16(1,1,1), p + v3s16(1,1,1)));
+
+	s32 i;
+	for(i=0; i<6; i++)
+	{
+		v3s16 p2 = p + dirs[i];
+		
+		u8 f = m_flags[m_area.index(p2)];
+
+		// Ignore inexistent and checked nodes
+		if(f & (VOXELFLAG_INEXISTENT | VOXELFLAG_CHECKED3))
+			continue;
+
+		MapNode &n = m_data[m_area.index(p2)];
+		
+		/*
+			If material is air:
+				add to active_nodes if there is flow-causing pressure.
+			NOTE: Do not remove anything from there. We cannot know
+			      here if some other neighbor of it causes flow.
+		*/
+		if(n.d == MATERIAL_AIR)
+		{
+			bool pressure_causes_flow = false;
+			// If block is at top
+			if(i == 0)
+			{
+				if(pr >= 3)
+					pressure_causes_flow = true;
+			}
+			// If block is at bottom
+			else if(i == 5)
+			{
+				pressure_causes_flow = true;
+			}
+			// If block is at side
+			else
+			{
+				if(pr >= 2)
+					pressure_causes_flow = true;
+			}
+			
+			if(pressure_causes_flow)
+			{
+				active_nodes[p2] = 1;
+			}
+
+			continue;
+		}
+
+		// Ignore non-liquid nodes
+		if(material_liquid(n.d) == false)
+			continue;
+
+		int pr2 = pr;
+		// If block is at top, pressure there is lower
+		if(i == 0)
+		{
+			if(pr2 > 0)
+				pr2--;
+		}
+		// If block is at bottom, pressure there is higher
+		else if(i == 5)
+		{
+			if(pr2 < 255)
+				pr2++;
+		}
+		
+		// Ignore if correct pressure is already set and is not on
+		// request_area
+		if(n.pressure == pr2 && request_area.contains(p2) == false)
+			continue;
+
+		spreadWaterPressure(p2, pr2, request_area, active_nodes, recur_count);
+	}
+}
+
+void VoxelManipulator::updateAreaWaterPressure(VoxelArea a,
+		core::map<v3s16, u8> &active_nodes,
+		bool checked3_is_clear)
+{
+	TimeTaker timer("updateAreaWaterPressure", g_device,
+			&updateareawaterpressure_time);
+
+	emerge(a);
+	
+	bool checked2_clear = false;
+	
+	if(checked3_is_clear == false)
+	{
+		//clearFlag(VOXELFLAG_CHECKED3);
+
+		clearFlag(VOXELFLAG_CHECKED3 | VOXELFLAG_CHECKED2);
+		checked2_clear = true;
+	}
+	
+
+	for(s32 z=a.MinEdge.Z; z<=a.MaxEdge.Z; z++)
+	for(s32 y=a.MinEdge.Y; y<=a.MaxEdge.Y; y++)
+	for(s32 x=a.MinEdge.X; x<=a.MaxEdge.X; x++)
+	{
+		v3s16 p(x,y,z);
+
+		u8 f = m_flags[m_area.index(p)];
+		// Ignore inexistent or checked nodes
+		if(f & (VOXELFLAG_INEXISTENT | VOXELFLAG_CHECKED3))
+			continue;
+		MapNode &n = m_data[m_area.index(p)];
+		// Ignore non-liquid nodes
+		if(material_liquid(n.d) == false)
+			continue;
+		
+		if(checked2_clear == false)
+		{
+			clearFlag(VOXELFLAG_CHECKED2);
+			checked2_clear = true;
+		}
+
+		checked2_clear = false;
+
+		s16 highest_y = -32768;
+		int recur_count = 0;
+		int pr = -1;
+
+		try
+		{
+			// 0-1ms @ recur_count <= 100
+			//TimeTaker timer("getWaterPressure", g_device);
+			pr = getWaterPressure(p, highest_y, recur_count);
+		}
+		catch(ProcessingLimitException &e)
+		{
+			//dstream<<"getWaterPressure ProcessingLimitException"<<std::endl;
+		}
+
+		if(pr == -1)
+		{
+			assert(highest_y != -32768);
+
+			pr = highest_y - p.Y + 1;
+			if(pr > 255)
+				pr = 255;
+
+			/*dstream<<"WARNING: Pressure at ("
+					<<p.X<<","<<p.Y<<","<<p.Z<<")"
+					<<" = "<<pr
+					//<<" and highest_y == -32768"
+					<<std::endl;
+			assert(highest_y != -32768);
+			continue;*/
+		}
+		
+		try
+		{
+			// 0ms
+			//TimeTaker timer("spreadWaterPressure", g_device);
+			spreadWaterPressure(p, pr, a, active_nodes, 0);
+		}
+		catch(ProcessingLimitException &e)
+		{
+			//dstream<<"getWaterPressure ProcessingLimitException"<<std::endl;
+		}
+	}
+}
+
+bool VoxelManipulator::flowWater(v3s16 removed_pos,
+		core::map<v3s16, u8> &active_nodes,
+		int recursion_depth, bool debugprint,
+		int *counter, int counterlimit)
 {
 	v3s16 dirs[6] = {
 		v3s16(0,1,0), // top
@@ -241,16 +607,43 @@ void VoxelManipulator::flowWater(v3s16 removed_pos)
 		v3s16(0,-1,0), // bottom
 	};
 
+	recursion_depth++;
+
 	v3s16 p;
+	
+	// Randomize horizontal order
+	static s32 cs = 0;
+	if(cs < 3)
+		cs++;
+	else
+		cs = 0;
+	s16 s1 = (cs & 1) ? 1 : -1;
+	s16 s2 = (cs & 2) ? 1 : -1;
+	//dstream<<"s1="<<s1<<", s2="<<s2<<std::endl;
 
+	{
+	TimeTaker timer1("flowWater pre", g_device, &flowwater_pre_time);
+	
 	// Load neighboring nodes
-	// TODO: A bigger area would be better
 	emerge(VoxelArea(removed_pos - v3s16(1,1,1), removed_pos + v3s16(1,1,1)));
-
+	
+	// Ignore incorrect removed_pos
+	{
+		u8 f = m_flags[m_area.index(removed_pos)];
+		// Ignore inexistent or checked node
+		if(f & (VOXELFLAG_INEXISTENT | VOXELFLAG_CHECKED))
+			return false;
+		MapNode &n = m_data[m_area.index(removed_pos)];
+		// Water can move only to air
+		if(n.d != MATERIAL_AIR)
+			return false;
+	}
+	
 	s32 i;
 	for(i=0; i<6; i++)
 	{
-		p = removed_pos + dirs[i];
+		p = removed_pos + v3s16(s1*dirs[i].X, dirs[i].Y, s2*dirs[i].Z);
+
 		u8 f = m_flags[m_area.index(p)];
 		// Inexistent or checked nodes can't move
 		if(f & (VOXELFLAG_INEXISTENT | VOXELFLAG_CHECKED))
@@ -280,30 +673,66 @@ void VoxelManipulator::flowWater(v3s16 removed_pos)
 
 	// If there is nothing to move, return
 	if(i==6)
-		return;
-	
+		return false;
+
 	// Switch nodes at p and removed_pos
-	MapNode n = m_data[m_area.index(p)];
+	u8 m = m_data[m_area.index(p)].d;
 	u8 f = m_flags[m_area.index(p)];
-	m_data[m_area.index(p)] = m_data[m_area.index(removed_pos)];
+	m_data[m_area.index(p)].d = m_data[m_area.index(removed_pos)].d;
 	m_flags[m_area.index(p)] = m_flags[m_area.index(removed_pos)];
-	m_data[m_area.index(removed_pos)] = n;
+	m_data[m_area.index(removed_pos)].d = m;
 	m_flags[m_area.index(removed_pos)] = f;
 
-	// Mark p checked
-	m_flags[m_area.index(p)] |= VOXELFLAG_CHECKED;
+	// Mark removed_pos checked
+	m_flags[m_area.index(removed_pos)] |= VOXELFLAG_CHECKED;
+	// If block was dropped from surface, increase pressure
+	if(i == 0 && m_data[m_area.index(removed_pos)].pressure == 1)
+	{
+		m_data[m_area.index(removed_pos)].pressure = 2;
+	}
 	
+	/*if(debugprint)
+	{
+		dstream<<"VoxelManipulator::flowWater(): Moved bubble:"<<std::endl;
+		print(dstream, VOXELPRINT_WATERPRESSURE);
+	}*/
+
 	// Update pressure
-	//TODO
+	VoxelArea a;
+	a.addPoint(p - v3s16(1,1,1));
+	a.addPoint(p + v3s16(1,1,1));
+	a.addPoint(removed_pos - v3s16(1,1,1));
+	a.addPoint(removed_pos + v3s16(1,1,1));
+	updateAreaWaterPressure(a, active_nodes);
+	
+	/*if(debugprint)
+	{
+		dstream<<"VoxelManipulator::flowWater(): Pressure updated:"<<std::endl;
+		print(dstream, VOXELPRINT_WATERPRESSURE);
+		//std::cin.get();
+	}*/
+
+	if(debugprint)
+	{
+		dstream<<"VoxelManipulator::flowWater(): step done:"<<std::endl;
+		print(dstream, VOXELPRINT_WATERPRESSURE);
+		//std::cin.get();
+	}
+	
+	}//timer1
 
 	// Flow water to the newly created empty position
-	flowWater(p);
+	flowWater(p, active_nodes, recursion_depth,
+			debugprint, counter, counterlimit);
 	
+find_again:
 	// Try flowing water to empty positions around removed_pos.
 	// They are checked in reverse order compared to the previous loop.
-	for(i=5; i>=0; i--)
+	for(s32 i=5; i>=0; i--)
 	{
-		p = removed_pos + dirs[i];
+		//v3s16 p = removed_pos + dirs[i];
+		p = removed_pos + v3s16(s1*dirs[i].X, dirs[i].Y, s2*dirs[i].Z);
+
 		u8 f = m_flags[m_area.index(p)];
 		// Water can't move to inexistent nodes
 		if(f & VOXELFLAG_INEXISTENT)
@@ -312,102 +741,291 @@ void VoxelManipulator::flowWater(v3s16 removed_pos)
 		// Water can only move to air
 		if(n.d != MATERIAL_AIR)
 			continue;
-		flowWater(p);
+			
+		// Flow water to node
+		bool moved =
+		flowWater(p, active_nodes, recursion_depth,
+				debugprint, counter, counterlimit);
+		
+		if(moved)
+		{
+			// Search again from all neighbors
+			goto find_again;
+		}
 	}
-}
 
-/*
-	MapVoxelManipulator
-*/
+	if(counter != NULL)
+	{
+		(*counter)++;
+		if((*counter) % 10 == 0)
+			dstream<<"flowWater(): moved "<<(*counter)<<" nodes"
+					<<std::endl;
 
-MapVoxelManipulator::MapVoxelManipulator(Map *map)
-{
-	m_map = map;
+		if(counterlimit != -1 && (*counter) > counterlimit)
+		{
+			dstream<<"Counter limit reached; returning"<<std::endl;
+			throw ProcessingLimitException("flowWater counterlimit reached");
+		}
+	}
+	
+	return true;
 }
-
-void MapVoxelManipulator::emerge(VoxelArea a)
+bool VoxelManipulator::flowWater(v3s16 removed_pos,
+		core::map<v3s16, u8> &active_nodes,
+		int recursion_depth, bool debugprint,
+		int *counter, int counterlimit)
 {
-	v3s16 size = a.getExtent();
+	v3s16 dirs[6] = {
+		v3s16(0,1,0), // top
+		v3s16(-1,0,0), // left
+		v3s16(1,0,0), // right
+		v3s16(0,0,-1), // front
+		v3s16(0,0,1), // back
+		v3s16(0,-1,0), // bottom
+	};
 
-	addArea(a);
+	recursion_depth++;
+
+	v3s16 p;
+	
+	// Randomize horizontal order
+	static s32 cs = 0;
+	if(cs < 3)
+		cs++;
+	else
+		cs = 0;
+	s16 s1 = (cs & 1) ? 1 : -1;
+	s16 s2 = (cs & 2) ? 1 : -1;
+	//dstream<<"s1="<<s1<<", s2="<<s2<<std::endl;
 
-	for(s16 z=0; z<size.Z; z++)
-	for(s16 y=0; y<size.Y; y++)
-	for(s16 x=0; x<size.X; x++)
 	{
-		v3s16 p(x,y,z);
-		s32 i = m_area.index(a.MinEdge + p);
-		// Don't touch nodes that have already been loaded
-		if(!(m_flags[i] & VOXELFLAG_NOT_LOADED))
+	TimeTaker timer1("flowWater pre", g_device, &flowwater_pre_time);
+	
+	// Load neighboring nodes
+	emerge(VoxelArea(removed_pos - v3s16(1,1,1), removed_pos + v3s16(1,1,1)));
+	
+	// Ignore incorrect removed_pos
+	{
+		u8 f = m_flags[m_area.index(removed_pos)];
+		// Ignore inexistent or checked node
+		if(f & (VOXELFLAG_INEXISTENT | VOXELFLAG_CHECKED))
+			return false;
+		MapNode &n = m_data[m_area.index(removed_pos)];
+		// Water can move only to air
+		if(n.d != MATERIAL_AIR)
+			return false;
+	}
+	
+	s32 i;
+	for(i=0; i<6; i++)
+	{
+		p = removed_pos + v3s16(s1*dirs[i].X, dirs[i].Y, s2*dirs[i].Z);
+
+		u8 f = m_flags[m_area.index(p)];
+		// Inexistent or checked nodes can't move
+		if(f & (VOXELFLAG_INEXISTENT | VOXELFLAG_CHECKED))
+			continue;
+		MapNode &n = m_data[m_area.index(p)];
+		// Only liquid nodes can move
+		if(material_liquid(n.d) == false)
+			continue;
+		// If block is at top, select it always
+		if(i == 0)
+		{
+			break;
+		}
+		// If block is at bottom, select it if it has enough pressure
+		if(i == 5)
+		{
+			if(n.pressure >= 3)
+				break;
 			continue;
-		try{
-			MapNode n = m_map->getNode(a.MinEdge + p);
-			m_data[i] = n;
-			m_flags[i] = 0;
 		}
-		catch(InvalidPositionException &e)
+		// Else block is at some side. Select it if it has enough pressure
+		if(n.pressure >= 2)
 		{
-			m_flags[i] = VOXELFLAG_INEXISTENT;
+			break;
 		}
 	}
-}
 
-void MapVoxelManipulator::blitBack
-		(core::map<v3s16, MapBlock*> & modified_blocks)
-{
-	/*
-		Initialize block cache
-	*/
-	v3s16 blockpos_last;
-	MapBlock *block = NULL;
-	bool block_checked_in_modified = false;
+	// If there is nothing to move, return
+	if(i==6)
+		return false;
 
-	for(s32 z=m_area.MinEdge.Z; z<=m_area.MaxEdge.Z; z++)
-	for(s32 y=m_area.MinEdge.Y; y<=m_area.MaxEdge.Y; y++)
-	for(s32 x=m_area.MinEdge.X; x<=m_area.MaxEdge.X; x++)
+	// Switch nodes at p and removed_pos
+	u8 m = m_data[m_area.index(p)].d;
+	u8 f = m_flags[m_area.index(p)];
+	m_data[m_area.index(p)].d = m_data[m_area.index(removed_pos)].d;
+	m_flags[m_area.index(p)] = m_flags[m_area.index(removed_pos)];
+	m_data[m_area.index(removed_pos)].d = m;
+	m_flags[m_area.index(removed_pos)] = f;
+
+	// Mark removed_pos checked
+	m_flags[m_area.index(removed_pos)] |= VOXELFLAG_CHECKED;
+	// If block was dropped from surface, increase pressure
+	if(i == 0 && m_data[m_area.index(removed_pos)].pressure == 1)
 	{
-		v3s16 p(x,y,z);
+		m_data[m_area.index(removed_pos)].pressure = 2;
+	}
+	
+	/*if(debugprint)
+	{
+		dstream<<"VoxelManipulator::flowWater(): Moved bubble:"<<std::endl;
+		print(dstream, VOXELPRINT_WATERPRESSURE);
+	}*/
+
+	// Update pressure
+	VoxelArea a;
+	a.addPoint(p - v3s16(1,1,1));
+	a.addPoint(p + v3s16(1,1,1));
+	a.addPoint(removed_pos - v3s16(1,1,1));
+	a.addPoint(removed_pos + v3s16(1,1,1));
+	updateAreaWaterPressure(a, active_nodes);
+	
+	/*if(debugprint)
+	{
+		dstream<<"VoxelManipulator::flowWater(): Pressure updated:"<<std::endl;
+		print(dstream, VOXELPRINT_WATERPRESSURE);
+		//std::cin.get();
+	}*/
+
+	if(debugprint)
+	{
+		dstream<<"VoxelManipulator::flowWater(): step done:"<<std::endl;
+		print(dstream, VOXELPRINT_WATERPRESSURE);
+		//std::cin.get();
+	}
+	
+	}//timer1
+
+	// Flow water to the newly created empty position
+	flowWater(p, active_nodes, recursion_depth,
+			debugprint, counter, counterlimit);
+	
+find_again:
+	// Try flowing water to empty positions around removed_pos.
+	// They are checked in reverse order compared to the previous loop.
+	for(s32 i=5; i>=0; i--)
+	{
+		//v3s16 p = removed_pos + dirs[i];
+		p = removed_pos + v3s16(s1*dirs[i].X, dirs[i].Y, s2*dirs[i].Z);
 
 		u8 f = m_flags[m_area.index(p)];
-		if(f & (VOXELFLAG_NOT_LOADED|VOXELFLAG_INEXISTENT))
+		// Water can't move to inexistent nodes
+		if(f & VOXELFLAG_INEXISTENT)
 			continue;
-
 		MapNode &n = m_data[m_area.index(p)];
+		// Water can only move to air
+		if(n.d != MATERIAL_AIR)
+			continue;
 			
-		v3s16 blockpos = getNodeBlockPos(p);
+		// Flow water to node
+		bool moved =
+		flowWater(p, active_nodes, recursion_depth,
+				debugprint, counter, counterlimit);
 		
-		try
+		if(moved)
 		{
-			// Get block
-			if(block == NULL || blockpos != blockpos_last){
-				block = m_map->getBlockNoCreate(blockpos);
-				blockpos_last = blockpos;
-				block_checked_in_modified = false;
-			}
-			
-			// Calculate relative position in block
-			v3s16 relpos = p - blockpos * MAP_BLOCKSIZE;
+			// Search again from all neighbors
+			goto find_again;
+		}
+	}
 
-			// Don't continue if nothing has changed here
-			if(block->getNode(relpos) == n)
-				continue;
+	if(counter != NULL)
+	{
+		(*counter)++;
+		if((*counter) % 10 == 0)
+			dstream<<"flowWater(): moved "<<(*counter)<<" nodes"
+					<<std::endl;
 
-			//m_map->setNode(m_area.MinEdge + p, n);
-			block->setNode(relpos, n);
-			
-			/*
-				Make sure block is in modified_blocks
-			*/
-			if(block_checked_in_modified == false)
-			{
-				modified_blocks[blockpos] = block;
-				block_checked_in_modified = true;
-			}
+		if(counterlimit != -1 && (*counter) > counterlimit)
+		{
+			dstream<<"Counter limit reached; returning"<<std::endl;
+			throw ProcessingLimitException("flowWater counterlimit reached");
 		}
-		catch(InvalidPositionException &e)
+	}
+	
+	return true;
+}
+
+void VoxelManipulator::flowWater(
+		core::map<v3s16, u8> &active_nodes,
+		int recursion_depth, bool debugprint,
+		int counterlimit)
+{
+	addarea_time = 0;
+	emerge_time = 0;
+	emerge_load_time = 0;
+	clearflag_time = 0;
+	updateareawaterpressure_time = 0;
+	flowwater_pre_time = 0;
+
+	TimeTaker timer1("flowWater (active_nodes)", g_device);
+
+	dstream<<"active_nodes.size() = "<<active_nodes.size()<<std::endl;
+
+	int counter = 0;
+
+	try
+	{
+
+	// Flow water to active nodes
+	for(;;)
+	{
+		// Clear check flags
+		clearFlag(VOXELFLAG_CHECKED);
+		
+		if(active_nodes.size() == 0)
+			break;
+
+		dstream<<"Selecting a new active_node"<<std::endl;
+
+#if 0
+		// Take first one
+		core::map<v3s16, u8>::Node
+				*n = active_nodes.getIterator().getNode();
+#endif
+
+#if 1
+		// Take random one
+		s32 k = (s32)rand() % (s32)active_nodes.size();
+		//s32 k = 0;
+		core::map<v3s16, u8>::Iterator
+				i = active_nodes.getIterator().getNode();
+		for(s32 j=0; j<k; j++)
 		{
+			i++;
 		}
+		core::map<v3s16, u8>::Node *n = i.getNode();
+#endif
+
+		v3s16 p = n->getKey();
+		active_nodes.remove(p);
+		flowWater(p, active_nodes, recursion_depth,
+				debugprint, &counter, counterlimit);
+	}
+
 	}
+	catch(ProcessingLimitException &e)
+	{
+		//dstream<<"getWaterPressure ProcessingLimitException"<<std::endl;
+	}
+	
+	v3s16 e = m_area.getExtent();
+	s32 v = m_area.getVolume();
+	dstream<<"flowWater (active): moved "<<counter<<" nodes, "
+			<<"area ended up as "
+			<<e.X<<"x"<<e.Y<<"x"<<e.Z<<" = "<<v
+			<<std::endl;
+	
+	dstream<<"addarea_time: "<<addarea_time
+			<<", emerge_time: "<<emerge_time
+			<<", emerge_load_time: "<<emerge_load_time
+			<<", clearflag_time: "<<clearflag_time
+			<<", flowwater_pre_time: "<<flowwater_pre_time
+			<<", updateareawaterpressure_time: "<<updateareawaterpressure_time
+			<<std::endl;
 }
 
+
 //END
diff --git a/src/voxel.h b/src/voxel.h
index 3a4dacd49..74c0a00e5 100644
--- a/src/voxel.h
+++ b/src/voxel.h
@@ -21,8 +21,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define VOXEL_HEADER
 
 #include "common_irrlicht.h"
-#include "mapblock.h"
 #include <iostream>
+#include "debug.h"
+#include "mapnode.h"
 
 /*
 	A fast voxel manipulator class
@@ -31,6 +32,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 */
 
 /*
+	Debug stuff
+*/
+extern u32 emerge_time;
+extern u32 emerge_load_time;
+
+/*
 	This class resembles aabbox3d<s16> a lot, but has inclusive
 	edges for saner handling of integer sizes
 */
@@ -53,8 +60,18 @@ public:
 		MaxEdge(p)
 	{
 	}
+	
+	/*
+		Modifying methods
+	*/
+
 	void addArea(VoxelArea &a)
 	{
+		if(getExtent() == v3s16(0,0,0))
+		{
+			*this = a;
+			return;
+		}
 		if(a.MinEdge.X < MinEdge.X) MinEdge.X = a.MinEdge.X;
 		if(a.MinEdge.Y < MinEdge.Y) MinEdge.Y = a.MinEdge.Y;
 		if(a.MinEdge.Z < MinEdge.Z) MinEdge.Z = a.MinEdge.Z;
@@ -64,6 +81,12 @@ public:
 	}
 	void addPoint(v3s16 p)
 	{
+		if(getExtent() == v3s16(0,0,0))
+		{
+			MinEdge = p;
+			MaxEdge = p;
+			return;
+		}
 		if(p.X < MinEdge.X) MinEdge.X = p.X;
 		if(p.Y < MinEdge.Y) MinEdge.Y = p.Y;
 		if(p.Z < MinEdge.Z) MinEdge.Z = p.Z;
@@ -71,6 +94,30 @@ public:
 		if(p.Y > MaxEdge.Y) MaxEdge.Y = p.Y;
 		if(p.Z > MaxEdge.Z) MaxEdge.Z = p.Z;
 	}
+	
+	// Pad with d nodes
+	void pad(v3s16 d)
+	{
+		MinEdge -= d;
+		MaxEdge += d;
+	}
+	
+	/*void operator+=(v3s16 off)
+	{
+		MinEdge += off;
+		MaxEdge += off;
+	}
+
+	void operator-=(v3s16 off)
+	{
+		MinEdge -= off;
+		MaxEdge -= off;
+	}*/
+
+	/*
+		const methods
+	*/
+
 	v3s16 getExtent() const
 	{
 		return MaxEdge - MinEdge + v3s16(1,1,1);
@@ -80,8 +127,13 @@ public:
 		v3s16 e = getExtent();
 		return (s32)e.X * (s32)e.Y * (s32)e.Z;
 	}
-	bool contains(VoxelArea &a) const
+	bool contains(const VoxelArea &a) const
 	{
+		// No area contains an empty area
+		// NOTE: Algorithms depend on this, so do not change.
+		if(a.getExtent() == v3s16(0,0,0))
+			return false;
+
 		return(
 			a.MinEdge.X >= MinEdge.X && a.MaxEdge.X <= MaxEdge.X &&
 			a.MinEdge.Y >= MinEdge.Y && a.MaxEdge.Y <= MaxEdge.Y &&
@@ -101,6 +153,95 @@ public:
 		return (MinEdge == other.MinEdge
 				&& MaxEdge == other.MaxEdge);
 	}
+
+	VoxelArea operator+(v3s16 off) const
+	{
+		return VoxelArea(MinEdge+off, MaxEdge+off);
+	}
+
+	VoxelArea operator-(v3s16 off) const
+	{
+		return VoxelArea(MinEdge-off, MaxEdge-off);
+	}
+
+	/*
+		Returns 0-6 non-overlapping areas that can be added to
+		a to make up this area.
+
+		a: area inside *this
+	*/
+	void diff(const VoxelArea &a, core::list<VoxelArea> &result)
+	{
+		/*
+			This can result in a maximum of 6 areas
+		*/
+
+		// If a is an empty area, return the current area as a whole
+		if(a.getExtent() == v3s16(0,0,0))
+		{
+			VoxelArea b = *this;
+			if(b.getVolume() != 0)
+				result.push_back(b);
+			return;
+		}
+
+		assert(contains(a));
+		
+		// Take back area, XY inclusive
+		{
+			v3s16 min(MinEdge.X, MinEdge.Y, a.MaxEdge.Z+1);
+			v3s16 max(MaxEdge.X, MaxEdge.Y, MaxEdge.Z);
+			VoxelArea b(min, max);
+			if(b.getVolume() != 0)
+				result.push_back(b);
+		}
+
+		// Take front area, XY inclusive
+		{
+			v3s16 min(MinEdge.X, MinEdge.Y, MinEdge.Z);
+			v3s16 max(MaxEdge.X, MaxEdge.Y, a.MinEdge.Z-1);
+			VoxelArea b(min, max);
+			if(b.getVolume() != 0)
+				result.push_back(b);
+		}
+
+		// Take top area, X inclusive
+		{
+			v3s16 min(MinEdge.X, a.MaxEdge.Y+1, a.MinEdge.Z);
+			v3s16 max(MaxEdge.X, MaxEdge.Y, a.MaxEdge.Z);
+			VoxelArea b(min, max);
+			if(b.getVolume() != 0)
+				result.push_back(b);
+		}
+
+		// Take bottom area, X inclusive
+		{
+			v3s16 min(MinEdge.X, MinEdge.Y, a.MinEdge.Z);
+			v3s16 max(MaxEdge.X, a.MinEdge.Y-1, a.MaxEdge.Z);
+			VoxelArea b(min, max);
+			if(b.getVolume() != 0)
+				result.push_back(b);
+		}
+
+		// Take left area, non-inclusive
+		{
+			v3s16 min(MinEdge.X, a.MinEdge.Y, a.MinEdge.Z);
+			v3s16 max(a.MinEdge.X-1, a.MaxEdge.Y, a.MaxEdge.Z);
+			VoxelArea b(min, max);
+			if(b.getVolume() != 0)
+				result.push_back(b);
+		}
+
+		// Take right area, non-inclusive
+		{
+			v3s16 min(a.MaxEdge.X+1, a.MinEdge.Y, a.MinEdge.Z);
+			v3s16 max(MaxEdge.X, a.MaxEdge.Y, a.MaxEdge.Z);
+			VoxelArea b(min, max);
+			if(b.getVolume() != 0)
+				result.push_back(b);
+		}
+
+	}
 	
 	/*
 		Translates position from virtual coordinates to array index
@@ -120,13 +261,15 @@ public:
 
 	void print(std::ostream &o) const
 	{
+		v3s16 e = getExtent();
 		o<<"("<<MinEdge.X
 		 <<","<<MinEdge.Y
 		 <<","<<MinEdge.Z
 		 <<")("<<MaxEdge.X
 		 <<","<<MaxEdge.Y
 		 <<","<<MaxEdge.Z
-		 <<")";
+		 <<")"
+		 <<"="<<e.X<<"x"<<e.Y<<"x"<<e.Z<<"="<<getVolume();
 	}
 
 	// Edges are inclusive
@@ -139,18 +282,35 @@ public:
 // Checked as being inexistent in source
 #define VOXELFLAG_INEXISTENT (1<<1)
 // Algorithm-dependent
+// flowWater: "visited"
 #define VOXELFLAG_CHECKED (1<<2)
+// Algorithm-dependent
+// getWaterPressure: "visited"
+#define VOXELFLAG_CHECKED2 (1<<3)
+// Algorithm-dependent
+// spreadWaterPressure: "visited"
+#define VOXELFLAG_CHECKED3 (1<<4)
+// Algorithm-dependent
+// water: "pressure check route node"
+#define VOXELFLAG_CHECKED4 (1<<5)
 
-class VoxelManipulator : public NodeContainer
+enum VoxelPrintMode
+{
+	VOXELPRINT_NOTHING,
+	VOXELPRINT_MATERIAL,
+	VOXELPRINT_WATERPRESSURE,
+};
+
+class VoxelManipulator /*: public NodeContainer*/
 {
 public:
 	VoxelManipulator();
-	~VoxelManipulator();
+	virtual ~VoxelManipulator();
 	
 	/*
 		Virtuals from NodeContainer
 	*/
-	virtual u16 nodeContainerId() const
+	/*virtual u16 nodeContainerId() const
 	{
 		return NODECONTAINER_ID_VOXELMANIPULATOR;
 	}
@@ -158,7 +318,7 @@ public:
 	{
 		emerge(p);
 		return !(m_flags[m_area.index(p)] & VOXELFLAG_INEXISTENT);
-	}
+	}*/
 	// These are a bit slow and shouldn't be used internally
 	MapNode getNode(v3s16 p)
 	{
@@ -166,7 +326,7 @@ public:
 
 		if(m_flags[m_area.index(p)] & VOXELFLAG_INEXISTENT)
 		{
-			dstream<<"ERROR: VoxelManipulator::getNode(): "
+			dstream<<"EXCEPT: VoxelManipulator::getNode(): "
 					<<"p=("<<p.X<<","<<p.Y<<","<<p.Z<<")"
 					<<", index="<<m_area.index(p)
 					<<", flags="<<(int)m_flags[m_area.index(p)]
@@ -214,19 +374,80 @@ public:
 		Control
 	*/
 
-	void clear();
-	
-	void print(std::ostream &o);
+	virtual void clear();
+
+	void print(std::ostream &o, VoxelPrintMode mode=VOXELPRINT_MATERIAL);
 	
 	void addArea(VoxelArea area);
 
 	/*
+		Copy data and set flags to 0
+		dst_area.getExtent() <= src_area.getExtent()
+	*/
+	void copyFrom(MapNode *src, VoxelArea src_area,
+			v3s16 from_pos, v3s16 to_pos, v3s16 size);
+
+	/*
 		Algorithms
 	*/
 
 	void interpolate(VoxelArea area);
 
-	void flowWater(v3s16 removed_pos);
+	void clearFlag(u8 flag);
+	
+	// VOXELFLAG_CHECKED2s must usually be cleared before calling
+	// -1: dead end, 0-255: pressure
+	// highest_y: Highest found water y is stored here.
+	//            Must be initialized to -32768
+	int getWaterPressure(v3s16 p, s16 &highest_y, int recur_count);
+
+	/*
+		VOXELFLAG_CHECKED3s must usually be cleared before calling.
+
+		active_nodes: surface-touching air nodes with flow-causing
+		pressure. set-like dummy map container.
+
+		Spreads pressure pr at node p to request_area or as far as
+		there is invalid pressure.
+	*/
+	void spreadWaterPressure(v3s16 p, int pr,
+			VoxelArea request_area,
+			core::map<v3s16, u8> &active_nodes,
+			int recur_count);
+	
+	/*
+		VOXELFLAG_CHECKED3s must usually be cleared before calling.
+	*/
+	void updateAreaWaterPressure(VoxelArea a,
+			core::map<v3s16, u8> &active_nodes,
+			bool checked3_is_clear=false);
+	
+	/*
+		Returns true if moved something
+	*/
+	bool flowWater(v3s16 removed_pos,
+			core::map<v3s16, u8> &active_nodes,
+			int recursion_depth=0,
+			bool debugprint=false, int *counter=NULL,
+			int counterlimit=-1
+	);
+
+	/*
+		To flow some water, call this with the target node in
+		active_nodes
+		TODO: Make the active_nodes map to contain some vectors
+		      that are properly sorted according to water flow order.
+			  The current order makes water flow strangely if the
+			  first one is always taken.
+			  No, active_nodes should preserve the order stuff is
+			  added to it, in addition to adhering the water flow
+			  order.
+	*/
+	void flowWater(core::map<v3s16, u8> &active_nodes,
+			int recursion_depth=0,
+			bool debugprint=false,
+			int counterlimit=-1
+	);
 
 	/*
 		Virtual functions
@@ -265,32 +486,24 @@ public:
 		MaxEdge is 1 higher than maximum allowed position
 	*/
 	VoxelArea m_area;
+	
 	/*
 		NULL if data size is 0 (extent (0,0,0))
 		Data is stored as [z*h*w + y*h + x]
 	*/
 	MapNode *m_data;
+
 	/*
 		Flags of all nodes
 	*/
 	u8 *m_flags;
+	
+	//TODO: Use these or remove them
+	//TODO: Would these make any speed improvement?
+	//bool m_pressure_route_valid;
+	//v3s16 m_pressure_route_surface;
 private:
 };
 
-class Map;
-
-class MapVoxelManipulator : public VoxelManipulator
-{
-public:
-	MapVoxelManipulator(Map *map);
-
-	virtual void emerge(VoxelArea a);
-
-	void blitBack(core::map<v3s16, MapBlock*> & modified_blocks);
-
-private:
-	Map *m_map;
-};
-
 #endif