utility.h: Change Buffer's interface to be more compatible with SharedBuffer's interf...
[oweals/minetest.git] / src / map.cpp
index dd32e55ba83dd9c4937f6910719460502f5ef2ca..d4eefc737ffbc2bdc35c96ea1428d57342a868cd 100644 (file)
@@ -21,20 +21,40 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapsector.h"
 #include "mapblock.h"
 #include "main.h"
+#ifndef SERVER
 #include "client.h"
+#endif
 #include "filesys.h"
 #include "utility.h"
 #include "voxel.h"
 #include "porting.h"
 #include "mapgen.h"
 #include "nodemetadata.h"
+#include "content_mapnode.h"
+#ifndef SERVER
+#include <IMaterialRenderer.h>
+#endif
+#include "settings.h"
+#include "log.h"
+#include "profiler.h"
+
+#define PP(x) "("<<(x).X<<","<<(x).Y<<","<<(x).Z<<")"
 
-extern "C" {
-       #include "sqlite3.h"
-}
 /*
        SQLite format specification:
        - Initially only replaces sectors/ and sectors2/
+       
+       If map.sqlite does not exist in the save dir
+       or the block was not found in the database
+       the map will try to load from sectors folder.
+       In either case, map.sqlite will be created
+       and all future saves will save there.
+       
+       Structure of map.sqlite:
+       Tables:
+               blocks
+                       (PK) INT pos
+                       BLOB data
 */
 
 /*
@@ -332,7 +352,7 @@ void Map::unspreadLight(enum LightBank bank,
                                                */
                                                /*if(light_sources.find(n2pos))
                                                {
-                                                       std::cout<<"Removed from light_sources"<<std::endl;
+                                                       infostream<<"Removed from light_sources"<<std::endl;
                                                        light_sources.remove(n2pos);
                                                }*/
                                        }
@@ -363,7 +383,7 @@ void Map::unspreadLight(enum LightBank bank,
                }
        }
 
-       /*dstream<<"unspreadLight(): Changed block "
+       /*infostream<<"unspreadLight(): Changed block "
                        <<blockchangecount<<" times"
                        <<" for "<<from_nodes.size()<<" nodes"
                        <<std::endl;*/
@@ -425,7 +445,7 @@ void Map::spreadLight(enum LightBank bank,
        {
                v3s16 pos = j.getNode()->getKey();
                //v3s16 pos = *j;
-               //dstream<<"pos=("<<pos.X<<","<<pos.Y<<","<<pos.Z<<")"<<std::endl;
+               //infostream<<"pos=("<<pos.X<<","<<pos.Y<<","<<pos.Z<<")"<<std::endl;
                v3s16 blockpos = getNodeBlockPos(pos);
 
                // Only fetch a new block if the block position has changed
@@ -530,7 +550,7 @@ void Map::spreadLight(enum LightBank bank,
                }
        }
 
-       /*dstream<<"spreadLight(): Changed block "
+       /*infostream<<"spreadLight(): Changed block "
                        <<blockchangecount<<" times"
                        <<" for "<<from_nodes.size()<<" nodes"
                        <<std::endl;*/
@@ -714,7 +734,7 @@ void Map::updateLighting(enum LightBank bank,
                                                dummy block.
                                        */
                                        //assert(0);
-                                       dstream<<"updateLighting(): InvalidPositionException"
+                                       infostream<<"updateLighting(): InvalidPositionException"
                                                        <<std::endl;
                                }
                        }
@@ -738,7 +758,7 @@ void Map::updateLighting(enum LightBank bank,
                                assert(0);
                        }
 
-                       /*dstream<<"Bottom for sunlight-propagated block ("
+                       /*infostream<<"Bottom for sunlight-propagated block ("
                                        <<pos.X<<","<<pos.Y<<","<<pos.Z<<") not valid"
                                        <<std::endl;*/
 
@@ -761,7 +781,7 @@ void Map::updateLighting(enum LightBank bank,
                generation for testing or whatever
        */
 #if 0
-       //if(g_settings.get(""))
+       //if(g_settings->get(""))
        {
                core::map<v3s16, MapBlock*>::Iterator i;
                i = blocks_to_update.getIterator();
@@ -785,7 +805,7 @@ void Map::updateLighting(enum LightBank bank,
        {
                u32 diff = modified_blocks.size() - count_was;
                count_was = modified_blocks.size();
-               dstream<<"unspreadLight modified "<<diff<<std::endl;
+               infostream<<"unspreadLight modified "<<diff<<std::endl;
        }
 
        {
@@ -797,7 +817,7 @@ void Map::updateLighting(enum LightBank bank,
        {
                u32 diff = modified_blocks.size() - count_was;
                count_was = modified_blocks.size();
-               dstream<<"spreadLight modified "<<diff<<std::endl;
+               infostream<<"spreadLight modified "<<diff<<std::endl;
        }
 #endif
 
@@ -853,7 +873,7 @@ void Map::updateLighting(enum LightBank bank,
                        //TimeTaker timer("blitBack");
                        vmanip.blitBack(modified_blocks);
                }
-               /*dstream<<"emerge_time="<<emerge_time<<std::endl;
+               /*infostream<<"emerge_time="<<emerge_time<<std::endl;
                emerge_time = 0;*/
        }
 
@@ -881,7 +901,7 @@ void Map::updateLighting(core::map<v3s16, MapBlock*> & a_blocks,
 /*
 */
 void Map::addNodeAndUpdate(v3s16 p, MapNode n,
-               core::map<v3s16, MapBlock*> &modified_blocks)
+               core::map<v3s16, MapBlock*> &modified_blocks, std::string &player_name)
 {
        /*PrintInfo(m_dout);
        m_dout<<DTIME<<"Map::addNodeAndUpdate(): p=("
@@ -1005,6 +1025,7 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
        if(meta_proto)
        {
                NodeMetadata *meta = meta_proto->clone();
+               meta->setOwner(player_name);
                setNodeMetadata(p, meta);
        }
 
@@ -1086,7 +1107,7 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
                v3s16 p2 = p + dirs[i];
 
                MapNode n2 = getNode(p2);
-               if(content_liquid(n2.getContent()))
+               if(content_liquid(n2.getContent()) || n2.getContent() == CONTENT_AIR)
                {
                        m_transforming_liquid.push_back(p2);
                }
@@ -1240,17 +1261,19 @@ void Map::removeNodeAndUpdate(v3s16 p,
        }
 
        /*
-               Add neighboring liquid nodes to transform queue.
+               Add neighboring liquid nodes and this node to transform queue.
+               (it's vital for the node itself to get updated last.)
        */
-       v3s16 dirs[6] = {
+       v3s16 dirs[7] = {
                v3s16(0,0,1), // back
                v3s16(0,1,0), // top
                v3s16(1,0,0), // right
                v3s16(0,0,-1), // front
                v3s16(0,-1,0), // bottom
                v3s16(-1,0,0), // left
+               v3s16(0,0,0), // self
        };
-       for(u16 i=0; i<6; i++)
+       for(u16 i=0; i<7; i++)
        {
                try
                {
@@ -1258,7 +1281,7 @@ void Map::removeNodeAndUpdate(v3s16 p,
                v3s16 p2 = p + dirs[i];
 
                MapNode n2 = getNode(p2);
-               if(content_liquid(n2.getContent()))
+               if(content_liquid(n2.getContent()) || n2.getContent() == CONTENT_AIR)
                {
                        m_transforming_liquid.push_back(p2);
                }
@@ -1279,7 +1302,8 @@ bool Map::addNodeWithEvent(v3s16 p, MapNode n)
        bool succeeded = true;
        try{
                core::map<v3s16, MapBlock*> modified_blocks;
-               addNodeAndUpdate(p, n, modified_blocks);
+               std::string st = std::string("");
+               addNodeAndUpdate(p, n, modified_blocks, st);
 
                // Copy modified_blocks to event
                for(core::map<v3s16, MapBlock*>::Iterator
@@ -1397,6 +1421,7 @@ void Map::timerUpdate(float dtime, float unload_timeout,
 
        core::map<v2s16, MapSector*>::Iterator si;
 
+       beginSave();
        si = m_sectors.getIterator();
        for(; si.atEnd() == false; si++)
        {
@@ -1406,6 +1431,7 @@ void Map::timerUpdate(float dtime, float unload_timeout,
 
                core::list<MapBlock*> blocks;
                sector->getBlocks(blocks);
+               
                for(core::list<MapBlock*>::Iterator i = blocks.begin();
                                i != blocks.end(); i++)
                {
@@ -1444,18 +1470,19 @@ void Map::timerUpdate(float dtime, float unload_timeout,
                        sector_deletion_queue.push_back(si.getNode()->getKey());
                }
        }
+       endSave();
        
        // Finally delete the empty sectors
        deleteSectors(sector_deletion_queue);
        
        if(deleted_blocks_count != 0)
        {
-               PrintInfo(dstream); // ServerMap/ClientMap:
-               dstream<<"Unloaded "<<deleted_blocks_count
+               PrintInfo(infostream); // ServerMap/ClientMap:
+               infostream<<"Unloaded "<<deleted_blocks_count
                                <<" blocks from memory";
                if(save_before_unloading)
-                       dstream<<", of which "<<saved_blocks_count<<" were written";
-               dstream<<"."<<std::endl;
+                       infostream<<", of which "<<saved_blocks_count<<" were written";
+               infostream<<"."<<std::endl;
        }
 }
 
@@ -1522,7 +1549,7 @@ void Map::unloadUnusedData(float timeout,
 
        deleteSectors(sector_deletion_queue);
 
-       dstream<<"Map: Unloaded "<<deleted_blocks_count<<" blocks from memory"
+       infostream<<"Map: Unloaded "<<deleted_blocks_count<<" blocks from memory"
                        <<", of which "<<saved_blocks_count<<" were wr."
                        <<std::endl;
 
@@ -1538,6 +1565,17 @@ void Map::PrintInfo(std::ostream &out)
 
 #define WATER_DROP_BOOST 4
 
+enum NeighborType {
+       NEIGHBOR_UPPER,
+       NEIGHBOR_SAME_LEVEL,
+       NEIGHBOR_LOWER
+};
+struct NodeNeighbor {
+       MapNode n;
+       NeighborType t;
+       v3s16 p;
+};
+
 void Map::transformLiquids(core::map<v3s16, MapBlock*> & modified_blocks)
 {
        DSTACK(__FUNCTION_NAME);
@@ -1547,10 +1585,21 @@ void Map::transformLiquids(core::map<v3s16, MapBlock*> & modified_blocks)
        u32 initial_size = m_transforming_liquid.size();
 
        /*if(initial_size != 0)
-               dstream<<"transformLiquids(): initial_size="<<initial_size<<std::endl;*/
+               infostream<<"transformLiquids(): initial_size="<<initial_size<<std::endl;*/
+
+       // list of nodes that due to viscosity have not reached their max level height
+       UniqueQueue<v3s16> must_reflow;
+       
+       // List of MapBlocks that will require a lighting update (due to lava)
+       core::map<v3s16, MapBlock*> lighting_modified_blocks;
 
        while(m_transforming_liquid.size() != 0)
        {
+               // This should be done here so that it is done when continue is used
+               if(loopcount >= initial_size * 3)
+                       break;
+               loopcount++;
+
                /*
                        Get a queued transforming liquid node
                */
@@ -1558,241 +1607,216 @@ void Map::transformLiquids(core::map<v3s16, MapBlock*> & modified_blocks)
 
                MapNode n0 = getNodeNoEx(p0);
 
-               // Don't deal with non-liquids
-               if(content_liquid(n0.getContent()) == false)
-                       continue;
-
-               bool is_source = !content_flowing_liquid(n0.getContent());
-
-               u8 liquid_level = 8;
-               if(is_source == false)
-                       liquid_level = n0.param2 & 0x0f;
-
-               // Turn possible source into non-source
-               u8 nonsource_c = make_liquid_flowing(n0.getContent());
-
                /*
-                       If not source, check that some node flows into this one
-                       and what is the level of liquid in this one
-               */
-               if(is_source == false)
-               {
-                       s8 new_liquid_level_max = -1;
-
-                       v3s16 dirs_from[5] = {
-                               v3s16(0,1,0), // top
-                               v3s16(0,0,1), // back
-                               v3s16(1,0,0), // right
-                               v3s16(0,0,-1), // front
-                               v3s16(-1,0,0), // left
-                       };
-                       for(u16 i=0; i<5; i++)
-                       {
-                               bool from_top = (i==0);
-
-                               v3s16 p2 = p0 + dirs_from[i];
-                               MapNode n2 = getNodeNoEx(p2);
-
-                               if(content_liquid(n2.getContent()))
-                               {
-                                       u8 n2_nonsource_c = make_liquid_flowing(n2.getContent());
-                                       // Check that the liquids are the same type
-                                       if(n2_nonsource_c != nonsource_c)
-                                       {
-                                               dstream<<"WARNING: Not handling: different liquids"
-                                                               " collide"<<std::endl;
-                                               continue;
-                                       }
-                                       bool n2_is_source = !content_flowing_liquid(n2.getContent());
-                                       s8 n2_liquid_level = 8;
-                                       if(n2_is_source == false)
-                                               n2_liquid_level = n2.param2 & 0x07;
+                       Collect information about current node
+                */
+               s8 liquid_level = -1;
+               u8 liquid_kind = CONTENT_IGNORE;
+               LiquidType liquid_type = content_features(n0.getContent()).liquid_type;
+               switch (liquid_type) {
+                       case LIQUID_SOURCE:
+                               liquid_level = LIQUID_LEVEL_SOURCE;
+                               liquid_kind = content_features(n0.getContent()).liquid_alternative_flowing;
+                               break;
+                       case LIQUID_FLOWING:
+                               liquid_level = (n0.param2 & LIQUID_LEVEL_MASK);
+                               liquid_kind = n0.getContent();
+                               break;
+                       case LIQUID_NONE:
+                               // if this is an air node, it *could* be transformed into a liquid. otherwise,
+                               // continue with the next node.
+                               if (n0.getContent() != CONTENT_AIR)
+                                       continue;
+                               liquid_kind = CONTENT_AIR;
+                               break;
+               }
 
-                                       s8 new_liquid_level = -1;
-                                       if(from_top)
-                                       {
-                                               //new_liquid_level = 7;
-                                               if(n2_liquid_level >= 7 - WATER_DROP_BOOST)
-                                                       new_liquid_level = 7;
-                                               else
-                                                       new_liquid_level = n2_liquid_level + WATER_DROP_BOOST;
+               /*
+                       Collect information about the environment
+                */
+               const v3s16 *dirs = g_6dirs;
+               NodeNeighbor sources[6]; // surrounding sources
+               int num_sources = 0;
+               NodeNeighbor flows[6]; // surrounding flowing liquid nodes
+               int num_flows = 0;
+               NodeNeighbor airs[6]; // surrounding air
+               int num_airs = 0;
+               NodeNeighbor neutrals[6]; // nodes that are solid or another kind of liquid
+               int num_neutrals = 0;
+               bool flowing_down = false;
+               for (u16 i = 0; i < 6; i++) {
+                       NeighborType nt = NEIGHBOR_SAME_LEVEL;
+                       switch (i) {
+                               case 1:
+                                       nt = NEIGHBOR_UPPER;
+                                       break;
+                               case 4:
+                                       nt = NEIGHBOR_LOWER;
+                                       break;
+                       }
+                       v3s16 npos = p0 + dirs[i];
+                       NodeNeighbor nb = {getNodeNoEx(npos), nt, npos};
+                       switch (content_features(nb.n.getContent()).liquid_type) {
+                               case LIQUID_NONE:
+                                       if (nb.n.getContent() == CONTENT_AIR) {
+                                               airs[num_airs++] = nb;
+                                               // if the current node is a water source the neighbor
+                                               // should be enqueded for transformation regardless of whether the
+                                               // current node changes or not.
+                                               if (nb.t != NEIGHBOR_UPPER && liquid_type != LIQUID_NONE)
+                                                       m_transforming_liquid.push_back(npos);
+                                               // if the current node happens to be a flowing node, it will start to flow down here.
+                                               if (nb.t == NEIGHBOR_LOWER) {
+                                                       flowing_down = true;
+                                               }
+                                       } else {
+                                               neutrals[num_neutrals++] = nb;
                                        }
-                                       else if(n2_liquid_level > 0)
-                                       {
-                                               new_liquid_level = n2_liquid_level - 1;
+                                       break;
+                               case LIQUID_SOURCE:
+                                       // if this node is not (yet) of a liquid type, choose the first liquid type we encounter 
+                                       if (liquid_kind == CONTENT_AIR)
+                                               liquid_kind = content_features(nb.n.getContent()).liquid_alternative_flowing;
+                                       if (content_features(nb.n.getContent()).liquid_alternative_flowing !=liquid_kind) {
+                                               neutrals[num_neutrals++] = nb;
+                                       } else {
+                                               sources[num_sources++] = nb;
                                        }
-
-                                       if(new_liquid_level > new_liquid_level_max)
-                                               new_liquid_level_max = new_liquid_level;
-                               }
-                       } //for
-
-                       /*
-                               If liquid level should be something else, update it and
-                               add all the neighboring water nodes to the transform queue.
-                       */
-                       if(new_liquid_level_max != liquid_level)
-                       {
-                               if(new_liquid_level_max == -1)
-                               {
-                                       // Remove water alltoghether
-                                       n0.setContent(CONTENT_AIR);
-                                       n0.param2 = 0;
-                                       setNode(p0, n0);
-                               }
-                               else
-                               {
-                                       n0.param2 = new_liquid_level_max;
-                                       setNode(p0, n0);
-                               }
-
-                               // Block has been modified
-                               {
-                                       v3s16 blockpos = getNodeBlockPos(p0);
-                                       MapBlock *block = getBlockNoCreateNoEx(blockpos);
-                                       if(block != NULL)
-                                               modified_blocks.insert(blockpos, block);
-                               }
-
-                               /*
-                                       Add neighboring non-source liquid nodes to transform queue.
-                               */
-                               v3s16 dirs[6] = {
-                                       v3s16(0,0,1), // back
-                                       v3s16(0,1,0), // top
-                                       v3s16(1,0,0), // right
-                                       v3s16(0,0,-1), // front
-                                       v3s16(0,-1,0), // bottom
-                                       v3s16(-1,0,0), // left
-                               };
-                               for(u16 i=0; i<6; i++)
-                               {
-                                       v3s16 p2 = p0 + dirs[i];
-
-                                       MapNode n2 = getNodeNoEx(p2);
-                                       if(content_flowing_liquid(n2.getContent()))
-                                       {
-                                               m_transforming_liquid.push_back(p2);
+                                       break;
+                               case LIQUID_FLOWING:
+                                       // if this node is not (yet) of a liquid type, choose the first liquid type we encounter
+                                       if (liquid_kind == CONTENT_AIR)
+                                               liquid_kind = content_features(nb.n.getContent()).liquid_alternative_flowing;
+                                       if (content_features(nb.n.getContent()).liquid_alternative_flowing != liquid_kind) {
+                                               neutrals[num_neutrals++] = nb;
+                                       } else {
+                                               flows[num_flows++] = nb;
+                                               if (nb.t == NEIGHBOR_LOWER)
+                                                       flowing_down = true;
                                        }
-                               }
+                                       break;
                        }
                }
 
-               // Get a new one from queue if the node has turned into non-water
-               if(content_liquid(n0.getContent()) == false)
-                       continue;
-
                /*
-                       Flow water from this node
-               */
-               v3s16 dirs_to[5] = {
-                       v3s16(0,-1,0), // bottom
-                       v3s16(0,0,1), // back
-                       v3s16(1,0,0), // right
-                       v3s16(0,0,-1), // front
-                       v3s16(-1,0,0), // left
-               };
-               for(u16 i=0; i<5; i++)
-               {
-                       bool to_bottom = (i == 0);
-
-                       // If liquid is at lowest possible height, it's not going
-                       // anywhere except down
-                       if(liquid_level == 0 && to_bottom == false)
-                               continue;
-
-                       u8 liquid_next_level = 0;
-                       // If going to bottom
-                       if(to_bottom)
-                       {
-                               //liquid_next_level = 7;
-                               if(liquid_level >= 7 - WATER_DROP_BOOST)
-                                       liquid_next_level = 7;
-                               else
-                                       liquid_next_level = liquid_level + WATER_DROP_BOOST;
-                       }
-                       else
-                               liquid_next_level = liquid_level - 1;
-
-                       bool n2_changed = false;
-                       bool flowed = false;
-
-                       v3s16 p2 = p0 + dirs_to[i];
-
-                       MapNode n2 = getNodeNoEx(p2);
-                       //dstream<<"[1] n2.param="<<(int)n2.param<<std::endl;
-
-                       if(content_liquid(n2.getContent()))
-                       {
-                               u8 n2_nonsource_c = make_liquid_flowing(n2.getContent());
-                               // Check that the liquids are the same type
-                               if(n2_nonsource_c != nonsource_c)
-                               {
-                                       dstream<<"WARNING: Not handling: different liquids"
-                                                       " collide"<<std::endl;
-                                       continue;
-                               }
-                               bool n2_is_source = !content_flowing_liquid(n2.getContent());
-                               u8 n2_liquid_level = 8;
-                               if(n2_is_source == false)
-                                       n2_liquid_level = n2.param2 & 0x07;
-
-                               if(to_bottom)
-                               {
-                                       flowed = true;
-                               }
-
-                               if(n2_is_source)
-                               {
-                                       // Just flow into the source, nothing changes.
-                                       // n2_changed is not set because destination didn't change
-                                       flowed = true;
-                               }
-                               else
-                               {
-                                       if(liquid_next_level > liquid_level)
-                                       {
-                                               n2.param2 = liquid_next_level;
-                                               setNode(p2, n2);
-
-                                               n2_changed = true;
-                                               flowed = true;
-                                       }
+                       decide on the type (and possibly level) of the current node
+                */
+               content_t new_node_content;
+               s8 new_node_level = -1;
+               s8 max_node_level = -1;
+               if (num_sources >= 2 || liquid_type == LIQUID_SOURCE) {
+                       // liquid_kind will be set to either the flowing alternative of the node (if it's a liquid)
+                       // or the flowing alternative of the first of the surrounding sources (if it's air), so
+                       // it's perfectly safe to use liquid_kind here to determine the new node content.
+                       new_node_content = content_features(liquid_kind).liquid_alternative_source;
+               } else if (num_sources == 1 && sources[0].t != NEIGHBOR_LOWER) {
+                       // liquid_kind is set properly, see above
+                       new_node_content = liquid_kind;
+                       max_node_level = new_node_level = LIQUID_LEVEL_MAX;
+               } else {
+                       // no surrounding sources, so get the maximum level that can flow into this node
+                       for (u16 i = 0; i < num_flows; i++) {
+                               u8 nb_liquid_level = (flows[i].n.param2 & LIQUID_LEVEL_MASK);
+                               switch (flows[i].t) {
+                                       case NEIGHBOR_UPPER:
+                                               if (nb_liquid_level + WATER_DROP_BOOST > max_node_level) {
+                                                       max_node_level = LIQUID_LEVEL_MAX;
+                                                       if (nb_liquid_level + WATER_DROP_BOOST < LIQUID_LEVEL_MAX)
+                                                               max_node_level = nb_liquid_level + WATER_DROP_BOOST;
+                                               } else if (nb_liquid_level > max_node_level)
+                                                       max_node_level = nb_liquid_level;
+                                               break;
+                                       case NEIGHBOR_LOWER:
+                                               break;
+                                       case NEIGHBOR_SAME_LEVEL:
+                                               if ((flows[i].n.param2 & LIQUID_FLOW_DOWN_MASK) != LIQUID_FLOW_DOWN_MASK &&
+                                                       nb_liquid_level > 0 && nb_liquid_level - 1 > max_node_level) {
+                                                       max_node_level = nb_liquid_level - 1;
+                                               }
+                                               break;
                                }
                        }
-                       else if(n2.getContent() == CONTENT_AIR)
-                       {
-                               n2.setContent(nonsource_c);
-                               n2.param2 = liquid_next_level;
-                               setNode(p2, n2);
 
-                               n2_changed = true;
-                               flowed = true;
-                       }
+                       u8 viscosity = content_features(liquid_kind).liquid_viscosity;
+                       if (viscosity > 1 && max_node_level != liquid_level) {
+                               // amount to gain, limited by viscosity
+                               // must be at least 1 in absolute value
+                               s8 level_inc = max_node_level - liquid_level;
+                               if (level_inc < -viscosity || level_inc > viscosity)
+                                       new_node_level = liquid_level + level_inc/viscosity;
+                               else if (level_inc < 0)
+                                       new_node_level = liquid_level - 1;
+                               else if (level_inc > 0)
+                                       new_node_level = liquid_level + 1;
+                               if (new_node_level != max_node_level)
+                                       must_reflow.push_back(p0);
+                       } else
+                               new_node_level = max_node_level;
+
+                       if (new_node_level >= 0)
+                               new_node_content = liquid_kind;
+                       else
+                               new_node_content = CONTENT_AIR;
 
-                       //dstream<<"[2] n2.param="<<(int)n2.param<<std::endl;
+               }
 
-                       if(n2_changed)
-                       {
-                               m_transforming_liquid.push_back(p2);
+               /*
+                       check if anything has changed. if not, just continue with the next node.
+                */
+               if (new_node_content == n0.getContent() && (content_features(n0.getContent()).liquid_type != LIQUID_FLOWING ||
+                                                                                ((n0.param2 & LIQUID_LEVEL_MASK) == (u8)new_node_level &&
+                                                                                ((n0.param2 & LIQUID_FLOW_DOWN_MASK) == LIQUID_FLOW_DOWN_MASK)
+                                                                                == flowing_down)))
+                       continue;
 
-                               v3s16 blockpos = getNodeBlockPos(p2);
-                               MapBlock *block = getBlockNoCreateNoEx(blockpos);
-                               if(block != NULL)
-                                       modified_blocks.insert(blockpos, block);
-                       }
 
-                       // If n2_changed to bottom, don't flow anywhere else
-                       if(to_bottom && flowed && !is_source)
-                               break;
+               /*
+                       update the current node
+                */
+               bool flow_down_enabled = (flowing_down && ((n0.param2 & LIQUID_FLOW_DOWN_MASK) != LIQUID_FLOW_DOWN_MASK));
+               if (content_features(new_node_content).liquid_type == LIQUID_FLOWING) {
+                       // set level to last 3 bits, flowing down bit to 4th bit
+                       n0.param2 = (flowing_down ? LIQUID_FLOW_DOWN_MASK : 0x00) | (new_node_level & LIQUID_LEVEL_MASK);
+               } else {
+                       // set the liquid level and flow bit to 0
+                       n0.param2 = ~(LIQUID_LEVEL_MASK | LIQUID_FLOW_DOWN_MASK);
+               }
+               n0.setContent(new_node_content);
+               setNode(p0, n0);
+               v3s16 blockpos = getNodeBlockPos(p0);
+               MapBlock *block = getBlockNoCreateNoEx(blockpos);
+               if(block != NULL) {
+                       modified_blocks.insert(blockpos, block);
+                       // If node emits light, MapBlock requires lighting update
+                       if(content_features(n0).light_source != 0)
+                               lighting_modified_blocks[block->getPos()] = block;
                }
 
-               loopcount++;
-               //if(loopcount >= 100000)
-               if(loopcount >= initial_size * 1)
-                       break;
+               /*
+                       enqueue neighbors for update if neccessary
+                */
+               switch (content_features(n0.getContent()).liquid_type) {
+                       case LIQUID_SOURCE:
+                       case LIQUID_FLOWING:
+                               // make sure source flows into all neighboring nodes
+                               for (u16 i = 0; i < num_flows; i++)
+                                       if (flows[i].t != NEIGHBOR_UPPER)
+                                               m_transforming_liquid.push_back(flows[i].p);
+                               for (u16 i = 0; i < num_airs; i++)
+                                       if (airs[i].t != NEIGHBOR_UPPER)
+                                               m_transforming_liquid.push_back(airs[i].p);
+                               break;
+                       case LIQUID_NONE:
+                               // this flow has turned to air; neighboring flows might need to do the same
+                               for (u16 i = 0; i < num_flows; i++)
+                                       m_transforming_liquid.push_back(flows[i].p);
+                               break;
+               }
        }
-       //dstream<<"Map::transformLiquids(): loopcount="<<loopcount<<std::endl;
+       //infostream<<"Map::transformLiquids(): loopcount="<<loopcount<<std::endl;
+       while (must_reflow.size() > 0)
+               m_transforming_liquid.push_back(must_reflow.pop_front());
+       updateLighting(lighting_modified_blocks, modified_blocks);
 }
 
 NodeMetadata* Map::getNodeMetadata(v3s16 p)
@@ -1800,9 +1824,14 @@ NodeMetadata* Map::getNodeMetadata(v3s16 p)
        v3s16 blockpos = getNodeBlockPos(p);
        v3s16 p_rel = p - blockpos*MAP_BLOCKSIZE;
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
-       if(block == NULL)
+       if(!block){
+               infostream<<"Map::getNodeMetadata(): Need to emerge "
+                               <<PP(blockpos)<<std::endl;
+               block = emergeBlock(blockpos, false);
+       }
+       if(!block)
        {
-               dstream<<"WARNING: Map::setNodeMetadata(): Block not found"
+               infostream<<"WARNING: Map::getNodeMetadata(): Block not found"
                                <<std::endl;
                return NULL;
        }
@@ -1815,9 +1844,14 @@ void Map::setNodeMetadata(v3s16 p, NodeMetadata *meta)
        v3s16 blockpos = getNodeBlockPos(p);
        v3s16 p_rel = p - blockpos*MAP_BLOCKSIZE;
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
-       if(block == NULL)
+       if(!block){
+               infostream<<"Map::setNodeMetadata(): Need to emerge "
+                               <<PP(blockpos)<<std::endl;
+               block = emergeBlock(blockpos, false);
+       }
+       if(!block)
        {
-               dstream<<"WARNING: Map::setNodeMetadata(): Block not found"
+               infostream<<"WARNING: Map::setNodeMetadata(): Block not found"
                                <<std::endl;
                return;
        }
@@ -1831,7 +1865,7 @@ void Map::removeNodeMetadata(v3s16 p)
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
        if(block == NULL)
        {
-               dstream<<"WARNING: Map::removeNodeMetadata(): Block not found"
+               infostream<<"WARNING: Map::removeNodeMetadata(): Block not found"
                                <<std::endl;
                return;
        }
@@ -1874,16 +1908,26 @@ void Map::nodeMetadataStep(float dtime,
 ServerMap::ServerMap(std::string savedir):
        Map(dout_server),
        m_seed(0),
-       m_map_metadata_changed(true)
+       m_map_metadata_changed(true),
+       m_database(NULL),
+       m_database_read(NULL),
+       m_database_write(NULL)
 {
-       dstream<<__FUNCTION_NAME<<std::endl;
+       infostream<<__FUNCTION_NAME<<std::endl;
 
        //m_chunksize = 8; // Takes a few seconds
 
-       m_seed = (((u64)(myrand()%0xffff)<<0)
-                       + ((u64)(myrand()%0xffff)<<16)
-                       + ((u64)(myrand()%0xffff)<<32)
-                       + ((u64)(myrand()%0xffff)<<48));
+       if (g_settings->get("fixed_map_seed").empty())
+       {
+               m_seed = (((u64)(myrand()%0xffff)<<0)
+                               + ((u64)(myrand()%0xffff)<<16)
+                               + ((u64)(myrand()%0xffff)<<32)
+                               + ((u64)(myrand()%0xffff)<<48));
+       }
+       else
+       {
+               m_seed = g_settings->getU64("fixed_map_seed");
+       }
 
        /*
                Experimental and debug stuff
@@ -1907,7 +1951,7 @@ ServerMap::ServerMap(std::string savedir):
                        // If directory is empty, it is safe to save into it.
                        if(fs::GetDirListing(m_savedir).size() == 0)
                        {
-                               dstream<<DTIME<<"Server: Empty save directory is valid."
+                               infostream<<"Server: Empty save directory is valid."
                                                <<std::endl;
                                m_map_saving_enabled = true;
                        }
@@ -1918,7 +1962,7 @@ ServerMap::ServerMap(std::string savedir):
                                        loadMapMeta();
                                }
                                catch(FileNotGoodException &e){
-                                       dstream<<DTIME<<"WARNING: Could not load map metadata"
+                                       infostream<<"WARNING: Could not load map metadata"
                                                        //<<" Disabling chunk-based generator."
                                                        <<std::endl;
                                        //m_chunksize = 0;
@@ -1929,18 +1973,18 @@ ServerMap::ServerMap(std::string savedir):
                                        loadChunkMeta();
                                }
                                catch(FileNotGoodException &e){
-                                       dstream<<DTIME<<"WARNING: Could not load chunk metadata."
+                                       infostream<<"WARNING: Could not load chunk metadata."
                                                        <<" Disabling chunk-based generator."
                                                        <<std::endl;
                                        m_chunksize = 0;
                                }*/
 
-                               /*dstream<<DTIME<<"Server: Successfully loaded chunk "
+                               /*infostream<<"Server: Successfully loaded chunk "
                                                "metadata and sector (0,0) from "<<savedir<<
                                                ", assuming valid save directory."
                                                <<std::endl;*/
 
-                               dstream<<DTIME<<"INFO: Server: Successfully loaded map "
+                               infostream<<"Server: Successfully loaded map "
                                                <<"and chunk metadata from "<<savedir
                                                <<", assuming valid save directory."
                                                <<std::endl;
@@ -1957,13 +2001,13 @@ ServerMap::ServerMap(std::string savedir):
        }
        catch(std::exception &e)
        {
-               dstream<<DTIME<<"WARNING: Server: Failed to load map from "<<savedir
+               infostream<<"WARNING: Server: Failed to load map from "<<savedir
                                <<", exception: "<<e.what()<<std::endl;
-               dstream<<"Please remove the map or fix it."<<std::endl;
-               dstream<<"WARNING: Map saving will be disabled."<<std::endl;
+               infostream<<"Please remove the map or fix it."<<std::endl;
+               infostream<<"WARNING: Map saving will be disabled."<<std::endl;
        }
 
-       dstream<<DTIME<<"INFO: Initializing new map."<<std::endl;
+       infostream<<"Initializing new map."<<std::endl;
 
        // Create zero sector
        emergeSector(v2s16(0,0));
@@ -1974,7 +2018,7 @@ ServerMap::ServerMap(std::string savedir):
 
 ServerMap::~ServerMap()
 {
-       dstream<<__FUNCTION_NAME<<std::endl;
+       infostream<<__FUNCTION_NAME<<std::endl;
 
        try
        {
@@ -1982,19 +2026,29 @@ ServerMap::~ServerMap()
                {
                        // Save only changed parts
                        save(true);
-                       dstream<<DTIME<<"Server: saved map to "<<m_savedir<<std::endl;
+                       infostream<<"Server: saved map to "<<m_savedir<<std::endl;
                }
                else
                {
-                       dstream<<DTIME<<"Server: map not saved"<<std::endl;
+                       infostream<<"Server: map not saved"<<std::endl;
                }
        }
        catch(std::exception &e)
        {
-               dstream<<DTIME<<"Server: Failed to save map to "<<m_savedir
+               infostream<<"Server: Failed to save map to "<<m_savedir
                                <<", exception: "<<e.what()<<std::endl;
        }
 
+       /*
+               Close database if it was opened
+       */
+       if(m_database_read)
+               sqlite3_finalize(m_database_read);
+       if(m_database_write)
+               sqlite3_finalize(m_database_write);
+       if(m_database)
+               sqlite3_close(m_database);
+
 #if 0
        /*
                Free all MapChunks
@@ -2010,8 +2064,10 @@ ServerMap::~ServerMap()
 
 void ServerMap::initBlockMake(mapgen::BlockMakeData *data, v3s16 blockpos)
 {
-       /*dstream<<"initBlockMake(): ("<<blockpos.X<<","<<blockpos.Y<<","
-                       <<blockpos.Z<<")"<<std::endl;*/
+       bool enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
+       if(enable_mapgen_debug_info)
+               infostream<<"initBlockMake(): ("<<blockpos.X<<","<<blockpos.Y<<","
+                               <<blockpos.Z<<")"<<std::endl;
        
        // Do nothing if not inside limits (+-1 because of neighbors)
        if(blockpos_over_limit(blockpos - v3s16(1,1,1)) ||
@@ -2041,25 +2097,28 @@ void ServerMap::initBlockMake(mapgen::BlockMakeData *data, v3s16 blockpos)
 
                        for(s16 y=-1; y<=1; y++)
                        {
-                               //MapBlock *block = createBlock(blockpos);
+                               v3s16 p(blockpos.X+x, blockpos.Y+y, blockpos.Z+z);
+                               //MapBlock *block = createBlock(p);
                                // 1) get from memory, 2) load from disk
-                               MapBlock *block = emergeBlock(blockpos, false);
+                               MapBlock *block = emergeBlock(p, false);
                                // 3) create a blank one
                                if(block == NULL)
-                                       block = createBlock(blockpos);
+                               {
+                                       block = createBlock(p);
+
+                                       /*
+                                               Block gets sunlight if this is true.
+
+                                               Refer to the map generator heuristics.
+                                       */
+                                       bool ug = mapgen::block_is_underground(data->seed, p);
+                                       block->setIsUnderground(ug);
+                               }
 
                                // Lighting will not be valid after make_chunk is called
                                block->setLightingExpired(true);
                                // Lighting will be calculated
                                //block->setLightingExpired(false);
-
-                               /*
-                                       Block gets sunlight if this is true.
-
-                                       This should be set to true when the top side of a block
-                                       is completely exposed to the sky.
-                               */
-                               block->setIsUnderground(false);
                        }
                }
        }
@@ -2091,19 +2150,19 @@ MapBlock* ServerMap::finishBlockMake(mapgen::BlockMakeData *data,
                core::map<v3s16, MapBlock*> &changed_blocks)
 {
        v3s16 blockpos = data->blockpos;
-       /*dstream<<"finishBlockMake(): ("<<blockpos.X<<","<<blockpos.Y<<","
+       /*infostream<<"finishBlockMake(): ("<<blockpos.X<<","<<blockpos.Y<<","
                        <<blockpos.Z<<")"<<std::endl;*/
 
        if(data->no_op)
        {
-               //dstream<<"finishBlockMake(): no-op"<<std::endl;
+               //infostream<<"finishBlockMake(): no-op"<<std::endl;
                return NULL;
        }
 
-       bool enable_mapgen_debug_info = g_settings.getBool("enable_mapgen_debug_info");
+       bool enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
 
-       /*dstream<<"Resulting vmanip:"<<std::endl;
-       data->vmanip.print(dstream);*/
+       /*infostream<<"Resulting vmanip:"<<std::endl;
+       data->vmanip.print(infostream);*/
        
        /*
                Blit generated stuff to map
@@ -2116,7 +2175,7 @@ MapBlock* ServerMap::finishBlockMake(mapgen::BlockMakeData *data,
        }
 
        if(enable_mapgen_debug_info)
-               dstream<<"finishBlockMake: changed_blocks.size()="
+               infostream<<"finishBlockMake: changed_blocks.size()="
                                <<changed_blocks.size()<<std::endl;
 
        /*
@@ -2135,10 +2194,14 @@ MapBlock* ServerMap::finishBlockMake(mapgen::BlockMakeData *data,
        assert(block);
 
        /*
-               Set is_underground flag for lighting with sunlight
+               Set is_underground flag for lighting with sunlight.
+
+               Refer to map generator heuristics.
+
+               NOTE: This is done in initChunkMake
        */
+       //block->setIsUnderground(mapgen::block_is_underground(data->seed, blockpos));
 
-       block->setIsUnderground(mapgen::block_is_underground(data->seed, blockpos));
 
        /*
                Add sunlight to central block.
@@ -2169,6 +2232,13 @@ MapBlock* ServerMap::finishBlockMake(mapgen::BlockMakeData *data,
 #if 1
                // Center block
                lighting_update_blocks.insert(block->getPos(), block);
+
+               /*{
+                       s16 x = 0;
+                       s16 z = 0;
+                       v3s16 p = block->getPos()+v3s16(x,1,z);
+                       lighting_update_blocks[p] = getBlockNoCreateNoEx(p);
+               }*/
 #endif
 #if 0
                // All modified blocks
@@ -2185,8 +2255,28 @@ MapBlock* ServerMap::finishBlockMake(mapgen::BlockMakeData *data,
                        lighting_update_blocks.insert(i.getNode()->getKey(),
                                        i.getNode()->getValue());
                }
+               /*// Also force-add all the upmost blocks for proper sunlight
+               for(s16 x=-1; x<=1; x++)
+               for(s16 z=-1; z<=1; z++)
+               {
+                       v3s16 p = block->getPos()+v3s16(x,1,z);
+                       lighting_update_blocks[p] = getBlockNoCreateNoEx(p);
+               }*/
 #endif
                updateLighting(lighting_update_blocks, changed_blocks);
+               
+               /*
+                       Set lighting to non-expired state in all of them.
+                       This is cheating, but it is not fast enough if all of them
+                       would actually be updated.
+               */
+               for(s16 x=-1; x<=1; x++)
+               for(s16 y=-1; y<=1; y++)
+               for(s16 z=-1; z<=1; z++)
+               {
+                       v3s16 p = block->getPos()+v3s16(x,y,z);
+                       getBlockNoCreateNoEx(p)->setLightingExpired(false);
+               }
 
                if(enable_mapgen_debug_info == false)
                        t.stop(true); // Hide output
@@ -2226,9 +2316,28 @@ MapBlock* ServerMap::finishBlockMake(mapgen::BlockMakeData *data,
        */
        //save(true);
 
-       /*dstream<<"finishBlockMake() done for ("<<blockpos.X<<","<<blockpos.Y<<","
+       /*infostream<<"finishBlockMake() done for ("<<blockpos.X<<","<<blockpos.Y<<","
                        <<blockpos.Z<<")"<<std::endl;*/
-       
+#if 0
+       if(enable_mapgen_debug_info)
+       {
+               /*
+                       Analyze resulting blocks
+               */
+               for(s16 x=-1; x<=1; x++)
+               for(s16 y=-1; y<=1; y++)
+               for(s16 z=-1; z<=1; z++)
+               {
+                       v3s16 p = block->getPos()+v3s16(x,y,z);
+                       MapBlock *block = getBlockNoCreateNoEx(p);
+                       char spos[20];
+                       snprintf(spos, 20, "(%2d,%2d,%2d)", x, y, z);
+                       infostream<<"Generated "<<spos<<": "
+                                       <<analyze_block(block)<<std::endl;
+               }
+       }
+#endif
+
        return block;
 }
 
@@ -2253,17 +2362,18 @@ ServerMapSector * ServerMap::createSector(v2s16 p2d)
        /*
                Try to load metadata from disk
        */
+#if 0
        if(loadSectorMeta(p2d) == true)
        {
                ServerMapSector *sector = (ServerMapSector*)getSectorNoGenerateNoEx(p2d);
                if(sector == NULL)
                {
-                       dstream<<"ServerMap::createSector(): loadSectorFull didn't make a sector"<<std::endl;
+                       infostream<<"ServerMap::createSector(): loadSectorFull didn't make a sector"<<std::endl;
                        throw InvalidPositionException("");
                }
                return sector;
        }
-
+#endif
        /*
                Do not create over-limit
        */
@@ -2300,11 +2410,11 @@ MapBlock * ServerMap::generateBlock(
 {
        DSTACKF("%s: p=(%d,%d,%d)", __FUNCTION_NAME, p.X, p.Y, p.Z);
        
-       /*dstream<<"generateBlock(): "
+       /*infostream<<"generateBlock(): "
                        <<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
                        <<std::endl;*/
        
-       bool enable_mapgen_debug_info = g_settings.getBool("enable_mapgen_debug_info");
+       bool enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
 
        TimeTaker timer("generateBlock");
        
@@ -2318,7 +2428,7 @@ MapBlock * ServerMap::generateBlock(
        */
        if(blockpos_over_limit(p))
        {
-               dstream<<__FUNCTION_NAME<<": Block position over limit"<<std::endl;
+               infostream<<__FUNCTION_NAME<<": Block position over limit"<<std::endl;
                throw InvalidPositionException("generateBlock(): pos. over limit");
        }
 
@@ -2364,7 +2474,7 @@ MapBlock * ServerMap::generateBlock(
                        MapNode n = block->getNode(p);
                        if(n.getContent() == CONTENT_IGNORE)
                        {
-                               dstream<<"CONTENT_IGNORE at "
+                               infostream<<"CONTENT_IGNORE at "
                                                <<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
                                                <<std::endl;
                                erroneus_content = true;
@@ -2438,7 +2548,7 @@ MapBlock * ServerMap::createBlock(v3s16 p)
        }
        catch(InvalidPositionException &e)
        {
-               dstream<<"createBlock: createSector() failed"<<std::endl;
+               infostream<<"createBlock: createSector() failed"<<std::endl;
                throw e;
        }
        /*
@@ -2448,7 +2558,7 @@ MapBlock * ServerMap::createBlock(v3s16 p)
        */
        /*catch(std::exception &e)
        {
-               dstream<<"createBlock: createSector() failed: "
+               infostream<<"createBlock: createSector() failed: "
                                <<e.what()<<std::endl;
                throw e;
        }*/
@@ -2477,7 +2587,7 @@ MapBlock * ServerMap::emergeBlock(v3s16 p, bool allow_generate)
        
        {
                MapBlock *block = getBlockNoCreateNoEx(p);
-               if(block)
+               if(block && block->isDummy() == false)
                        return block;
        }
 
@@ -2515,194 +2625,123 @@ MapBlock * ServerMap::emergeBlock(v3s16 p, bool allow_generate)
        return NULL;
 }
 
+s16 ServerMap::findGroundLevel(v2s16 p2d)
+{
 #if 0
        /*
-               Do not generate over-limit
-       */
-       if(p.X < -MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.X > MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.Y < -MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.Y > MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.Z < -MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.Z > MAP_GENERATION_LIMIT / MAP_BLOCKSIZE)
-               throw InvalidPositionException("emergeBlock(): pos. over limit");
-       
-       v2s16 p2d(p.X, p.Z);
-       s16 block_y = p.Y;
-       /*
-               This will create or load a sector if not found in memory.
-               If block exists on disk, it will be loaded.
+               Uh, just do something random...
        */
-       ServerMapSector *sector;
-       try{
-               sector = createSector(p2d);
-               //sector = emergeSector(p2d, changed_blocks);
-       }
-       catch(InvalidPositionException &e)
+       // Find existing map from top to down
+       s16 max=63;
+       s16 min=-64;
+       v3s16 p(p2d.X, max, p2d.Y);
+       for(; p.Y>min; p.Y--)
        {
-               dstream<<"emergeBlock: createSector() failed: "
-                               <<e.what()<<std::endl;
-               dstream<<"Path to failed sector: "<<getSectorDir(p2d)
-                               <<std::endl
-                               <<"You could try to delete it."<<std::endl;
-               throw e;
+               MapNode n = getNodeNoEx(p);
+               if(n.getContent() != CONTENT_IGNORE)
+                       break;
        }
-       catch(VersionMismatchException &e)
+       if(p.Y == min)
+               goto plan_b;
+       // If this node is not air, go to plan b
+       if(getNodeNoEx(p).getContent() != CONTENT_AIR)
+               goto plan_b;
+       // Search existing walkable and return it
+       for(; p.Y>min; p.Y--)
        {
-               dstream<<"emergeBlock: createSector() failed: "
-                               <<e.what()<<std::endl;
-               dstream<<"Path to failed sector: "<<getSectorDir(p2d)
-                               <<std::endl
-                               <<"You could try to delete it."<<std::endl;
-               throw e;
+               MapNode n = getNodeNoEx(p);
+               if(content_walkable(n.d) && n.getContent() != CONTENT_IGNORE)
+                       return p.Y;
        }
 
+       // Move to plan b
+plan_b:
+#endif
+
        /*
-               Try to get a block from the sector
+               Determine from map generator noise functions
        */
+       
+       s16 level = mapgen::find_ground_level_from_noise(m_seed, p2d, 1);
+       return level;
 
-       bool does_not_exist = false;
-       bool lighting_expired = false;
-       MapBlock *block = sector->getBlockNoCreateNoEx(block_y);
+       //double level = base_rock_level_2d(m_seed, p2d) + AVERAGE_MUD_AMOUNT;
+       //return (s16)level;
+}
+
+void ServerMap::createDatabase() {
+       int e;
+       assert(m_database);
+       e = sqlite3_exec(m_database,
+               "CREATE TABLE IF NOT EXISTS `blocks` ("
+                       "`pos` INT NOT NULL PRIMARY KEY,"
+                       "`data` BLOB"
+               ");"
+       , NULL, NULL, NULL);
+       if(e == SQLITE_ABORT)
+               throw FileNotGoodException("Could not create database structure");
+       else
+               infostream<<"Server: Database structure was created";
+}
+
+void ServerMap::verifyDatabase() {
+       if(m_database)
+               return;
        
-       // If not found, try loading from disk
-       if(block == NULL)
        {
-               block = loadBlock(p);
-       }
+               std::string dbp = m_savedir + DIR_DELIM + "map.sqlite";
+               bool needs_create = false;
+               int d;
+               
+               /*
+                       Open the database connection
+               */
        
-       // Handle result
-       if(block == NULL)
-       {
-               does_not_exist = true;
-       }
-       else if(block->isDummy() == true)
-       {
-               does_not_exist = true;
-       }
-       else if(block->getLightingExpired())
-       {
-               lighting_expired = true;
-       }
-       else
-       {
-               // Valid block
-               //dstream<<"emergeBlock(): Returning already valid block"<<std::endl;
-               return block;
-       }
+               createDirs(m_savedir);
        
-       /*
-               If block was not found on disk and not going to generate a
-               new one, make sure there is a dummy block in place.
-       */
-       if(only_from_disk && (does_not_exist || lighting_expired))
-       {
-               //dstream<<"emergeBlock(): Was not on disk but not generating"<<std::endl;
-
-               if(block == NULL)
-               {
-                       // Create dummy block
-                       block = new MapBlock(this, p, true);
-
-                       // Add block to sector
-                       sector->insertBlock(block);
+               if(!fs::PathExists(dbp))
+                       needs_create = true;
+       
+               d = sqlite3_open_v2(dbp.c_str(), &m_database, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, NULL);
+               if(d != SQLITE_OK) {
+                       infostream<<"WARNING: Database failed to open: "<<sqlite3_errmsg(m_database)<<std::endl;
+                       throw FileNotGoodException("Cannot open database file");
                }
-               // Done.
-               return block;
-       }
-
-       //dstream<<"Not found on disk, generating."<<std::endl;
-       // 0ms
-       //TimeTaker("emergeBlock() generate");
-
-       //dstream<<"emergeBlock(): Didn't find valid block -> making one"<<std::endl;
-
-       /*
-               If the block doesn't exist, generate the block.
-       */
-       if(does_not_exist)
-       {
-               block = generateBlock(p, block, sector, changed_blocks,
-                               lighting_invalidated_blocks); 
-       }
-
-       if(lighting_expired)
-       {
-               lighting_invalidated_blocks.insert(p, block);
-       }
-
-#if 0
-       /*
-               Initially update sunlight
-       */
-       {
-               core::map<v3s16, bool> light_sources;
-               bool black_air_left = false;
-               bool bottom_invalid =
-                               block->propagateSunlight(light_sources, true,
-                               &black_air_left);
-
-               // If sunlight didn't reach everywhere and part of block is
-               // above ground, lighting has to be properly updated
-               //if(black_air_left && some_part_underground)
-               if(black_air_left)
-               {
-                       lighting_invalidated_blocks[block->getPos()] = block;
+               
+               if(needs_create)
+                       createDatabase();
+       
+               d = sqlite3_prepare(m_database, "SELECT `data` FROM `blocks` WHERE `pos`=? LIMIT 1", -1, &m_database_read, NULL);
+               if(d != SQLITE_OK) {
+                       infostream<<"WARNING: Database read statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
+                       throw FileNotGoodException("Cannot prepare read statement");
                }
-
-               if(bottom_invalid)
-               {
-                       lighting_invalidated_blocks[block->getPos()] = block;
+               
+               d = sqlite3_prepare(m_database, "REPLACE INTO `blocks` VALUES(?, ?)", -1, &m_database_write, NULL);
+               if(d != SQLITE_OK) {
+                       infostream<<"WARNING: Database write statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
+                       throw FileNotGoodException("Cannot prepare write statement");
+               }
+               
+               d = sqlite3_prepare(m_database, "SELECT `pos` FROM `blocks`", -1, &m_database_list, NULL);
+               if(d != SQLITE_OK) {
+                       infostream<<"WARNING: Database list statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
+                       throw FileNotGoodException("Cannot prepare read statement");
                }
+               
+               infostream<<"Server: Database opened"<<std::endl;
        }
-#endif
-       
-       return block;
 }
-#endif
-
-s16 ServerMap::findGroundLevel(v2s16 p2d)
-{
-#if 0
-       /*
-               Uh, just do something random...
-       */
-       // Find existing map from top to down
-       s16 max=63;
-       s16 min=-64;
-       v3s16 p(p2d.X, max, p2d.Y);
-       for(; p.Y>min; p.Y--)
-       {
-               MapNode n = getNodeNoEx(p);
-               if(n.getContent() != CONTENT_IGNORE)
-                       break;
-       }
-       if(p.Y == min)
-               goto plan_b;
-       // If this node is not air, go to plan b
-       if(getNodeNoEx(p).getContent() != CONTENT_AIR)
-               goto plan_b;
-       // Search existing walkable and return it
-       for(; p.Y>min; p.Y--)
-       {
-               MapNode n = getNodeNoEx(p);
-               if(content_walkable(n.d) && n.getContent() != CONTENT_IGNORE)
-                       return p.Y;
-       }
-
-       // Move to plan b
-plan_b:
-#endif
 
-       /*
-               Determine from map generator noise functions
-       */
-       
-       s16 level = mapgen::find_ground_level_from_noise(m_seed, p2d, 1);
-       return level;
+bool ServerMap::loadFromFolders() {
+       if(!m_database && !fs::PathExists(m_savedir + DIR_DELIM + "map.sqlite"))
+               return true;
+       return false;
+}
 
-       //double level = base_rock_level_2d(m_seed, p2d) + AVERAGE_MUD_AMOUNT;
-       //return (s16)level;
+sqlite3_int64 ServerMap::getBlockAsInteger(const v3s16 pos) {
+       return (sqlite3_int64)pos.Z*16777216 +
+               (sqlite3_int64)pos.Y*4096 + (sqlite3_int64)pos.X;
 }
 
 void ServerMap::createDirs(std::string path)
@@ -2725,13 +2764,13 @@ std::string ServerMap::getSectorDir(v2s16 pos, int layout)
                                (unsigned int)pos.X&0xffff,
                                (unsigned int)pos.Y&0xffff);
 
-                       return m_savedir + "/sectors/" + cc;
+                       return m_savedir + DIR_DELIM + "sectors" + DIR_DELIM + cc;
                case 2:
-                       snprintf(cc, 9, "%.3x/%.3x",
+                       snprintf(cc, 9, "%.3x" DIR_DELIM "%.3x",
                                (unsigned int)pos.X&0xfff,
                                (unsigned int)pos.Y&0xfff);
 
-                       return m_savedir + "/sectors2/" + cc;
+                       return m_savedir + DIR_DELIM + "sectors2" + DIR_DELIM + cc;
                default:
                        assert(false);
        }
@@ -2741,7 +2780,7 @@ v2s16 ServerMap::getSectorPos(std::string dirname)
 {
        unsigned int x, y;
        int r;
-       size_t spos = dirname.rfind('/') + 1;
+       size_t spos = dirname.rfind(DIR_DELIM_C) + 1;
        assert(spos != std::string::npos);
        if(dirname.size() - spos == 8)
        {
@@ -2751,7 +2790,7 @@ v2s16 ServerMap::getSectorPos(std::string dirname)
        else if(dirname.size() - spos == 3)
        {
                // New layout
-               r = sscanf(dirname.substr(spos-4).c_str(), "%3x/%3x", &x, &y);
+               r = sscanf(dirname.substr(spos-4).c_str(), "%3x" DIR_DELIM "%3x", &x, &y);
                // Sign-extend the 12 bit values up to 16 bits...
                if(x&0x800) x|=0xF000;
                if(y&0x800) y|=0xF000;
@@ -2791,12 +2830,12 @@ void ServerMap::save(bool only_changed)
        DSTACK(__FUNCTION_NAME);
        if(m_map_saving_enabled == false)
        {
-               dstream<<DTIME<<"WARNING: Not saving map, saving disabled."<<std::endl;
+               infostream<<"WARNING: Not saving map, saving disabled."<<std::endl;
                return;
        }
        
        if(only_changed == false)
-               dstream<<DTIME<<"ServerMap: Saving whole map, this can take time."
+               infostream<<"ServerMap: Saving whole map, this can take time."
                                <<std::endl;
        
        if(only_changed == false || m_map_metadata_changed)
@@ -2808,6 +2847,7 @@ void ServerMap::save(bool only_changed)
        u32 block_count = 0;
        u32 block_count_all = 0; // Number of blocks in memory
        
+       beginSave();
        core::map<v2s16, MapSector*>::Iterator i = m_sectors.getIterator();
        for(; i.atEnd() == false; i++)
        {
@@ -2822,6 +2862,8 @@ void ServerMap::save(bool only_changed)
                core::list<MapBlock*> blocks;
                sector->getBlocks(blocks);
                core::list<MapBlock*>::Iterator j;
+               
+               //sqlite3_exec(m_database, "BEGIN;", NULL, NULL, NULL);
                for(j=blocks.begin(); j!=blocks.end(); j++)
                {
                        MapBlock *block = *j;
@@ -2834,14 +2876,16 @@ void ServerMap::save(bool only_changed)
                                saveBlock(block);
                                block_count++;
 
-                               /*dstream<<"ServerMap: Written block ("
+                               /*infostream<<"ServerMap: Written block ("
                                                <<block->getPos().X<<","
                                                <<block->getPos().Y<<","
                                                <<block->getPos().Z<<")"
                                                <<std::endl;*/
                        }
+               //sqlite3_exec(m_database, "COMMIT;", NULL, NULL, NULL);
                }
        }
+       endSave();
 
        /*
                Only print if something happened or saved whole map
@@ -2849,7 +2893,7 @@ void ServerMap::save(bool only_changed)
        if(only_changed == false || sector_meta_count != 0
                        || block_count != 0)
        {
-               dstream<<DTIME<<"ServerMap: Written: "
+               infostream<<"ServerMap: Written: "
                                <<sector_meta_count<<" sector metadata files, "
                                <<block_count<<" block files"
                                <<", "<<block_count_all<<" blocks in memory."
@@ -2857,21 +2901,67 @@ void ServerMap::save(bool only_changed)
        }
 }
 
+static s32 unsignedToSigned(s32 i, s32 max_positive)
+{
+       if(i < max_positive)
+               return i;
+       else
+               return i - 2*max_positive;
+}
+
+// modulo of a negative number does not work consistently in C
+static sqlite3_int64 pythonmodulo(sqlite3_int64 i, sqlite3_int64 mod)
+{
+       if(i >= 0)
+               return i % mod;
+       return mod - ((-i) % mod);
+}
+
+v3s16 ServerMap::getIntegerAsBlock(sqlite3_int64 i)
+{
+       s32 x = unsignedToSigned(pythonmodulo(i, 4096), 2048);
+       i = (i - x) / 4096;
+       s32 y = unsignedToSigned(pythonmodulo(i, 4096), 2048);
+       i = (i - y) / 4096;
+       s32 z = unsignedToSigned(pythonmodulo(i, 4096), 2048);
+       return v3s16(x,y,z);
+}
+
+void ServerMap::listAllLoadableBlocks(core::list<v3s16> &dst)
+{
+       if(loadFromFolders()){
+               errorstream<<"Map::listAllLoadableBlocks(): Result will be missing "
+                               <<"all blocks that are stored in flat files"<<std::endl;
+       }
+       
+       {
+               verifyDatabase();
+               
+               while(sqlite3_step(m_database_list) == SQLITE_ROW)
+               {
+                       sqlite3_int64 block_i = sqlite3_column_int64(m_database_list, 0);
+                       v3s16 p = getIntegerAsBlock(block_i);
+                       //dstream<<"block_i="<<block_i<<" p="<<PP(p)<<std::endl;
+                       dst.push_back(p);
+               }
+       }
+}
+
 void ServerMap::saveMapMeta()
 {
        DSTACK(__FUNCTION_NAME);
        
-       dstream<<"INFO: ServerMap::saveMapMeta(): "
+       infostream<<"ServerMap::saveMapMeta(): "
                        <<"seed="<<m_seed
                        <<std::endl;
 
        createDirs(m_savedir);
        
-       std::string fullpath = m_savedir + "/map_meta.txt";
+       std::string fullpath = m_savedir + DIR_DELIM + "map_meta.txt";
        std::ofstream os(fullpath.c_str(), std::ios_base::binary);
        if(os.good() == false)
        {
-               dstream<<"ERROR: ServerMap::saveMapMeta(): "
+               infostream<<"ERROR: ServerMap::saveMapMeta(): "
                                <<"could not open"<<fullpath<<std::endl;
                throw FileNotGoodException("Cannot open chunk metadata");
        }
@@ -2890,14 +2980,14 @@ void ServerMap::loadMapMeta()
 {
        DSTACK(__FUNCTION_NAME);
        
-       dstream<<"INFO: ServerMap::loadMapMeta(): Loading map metadata"
+       infostream<<"ServerMap::loadMapMeta(): Loading map metadata"
                        <<std::endl;
 
-       std::string fullpath = m_savedir + "/map_meta.txt";
+       std::string fullpath = m_savedir + DIR_DELIM + "map_meta.txt";
        std::ifstream is(fullpath.c_str(), std::ios_base::binary);
        if(is.good() == false)
        {
-               dstream<<"ERROR: ServerMap::loadMapMeta(): "
+               infostream<<"ERROR: ServerMap::loadMapMeta(): "
                                <<"could not open"<<fullpath<<std::endl;
                throw FileNotGoodException("Cannot open map metadata");
        }
@@ -2919,9 +3009,7 @@ void ServerMap::loadMapMeta()
 
        m_seed = params.getU64("seed");
 
-       dstream<<"INFO: ServerMap::loadMapMeta(): "
-                       <<"seed="<<m_seed
-                       <<std::endl;
+       infostream<<"ServerMap::loadMapMeta(): "<<"seed="<<m_seed<<std::endl;
 }
 
 void ServerMap::saveSectorMeta(ServerMapSector *sector)
@@ -2934,7 +3022,7 @@ void ServerMap::saveSectorMeta(ServerMapSector *sector)
        std::string dir = getSectorDir(pos);
        createDirs(dir);
        
-       std::string fullpath = dir + "/meta";
+       std::string fullpath = dir + DIR_DELIM + "meta";
        std::ofstream o(fullpath.c_str(), std::ios_base::binary);
        if(o.good() == false)
                throw FileNotGoodException("Cannot open sector metafile");
@@ -2952,7 +3040,7 @@ MapSector* ServerMap::loadSectorMeta(std::string sectordir, bool save_after_load
 
        ServerMapSector *sector = NULL;
 
-       std::string fullpath = sectordir + "/meta";
+       std::string fullpath = sectordir + DIR_DELIM + "meta";
        std::ifstream is(fullpath.c_str(), std::ios_base::binary);
        if(is.good() == false)
        {
@@ -2960,7 +3048,7 @@ MapSector* ServerMap::loadSectorMeta(std::string sectordir, bool save_after_load
                // format. Just go ahead and create the sector.
                if(fs::PathExists(sectordir))
                {
-                       /*dstream<<"ServerMap::loadSectorMeta(): Sector metafile "
+                       /*infostream<<"ServerMap::loadSectorMeta(): Sector metafile "
                                        <<fullpath<<" doesn't exist but directory does."
                                        <<" Continuing with a sector with no metadata."
                                        <<std::endl;*/
@@ -3091,7 +3179,7 @@ bool ServerMap::loadSectorFull(v2s16 p2d)
 
        if(loadlayout != 2)
        {
-               dstream<<"Sector converted to new layout - deleting "<<
+               infostream<<"Sector converted to new layout - deleting "<<
                        sectordir1<<std::endl;
                fs::RecursiveDelete(sectordir1);
        }
@@ -3100,6 +3188,18 @@ bool ServerMap::loadSectorFull(v2s16 p2d)
 }
 #endif
 
+void ServerMap::beginSave() {
+       verifyDatabase();
+       if(sqlite3_exec(m_database, "BEGIN;", NULL, NULL, NULL) != SQLITE_OK)
+               infostream<<"WARNING: beginSave() failed, saving might be slow.";
+}
+
+void ServerMap::endSave() {
+       verifyDatabase();
+       if(sqlite3_exec(m_database, "COMMIT;", NULL, NULL, NULL) != SQLITE_OK)
+               infostream<<"WARNING: endSave() failed, map might not have saved.";
+}
+
 void ServerMap::saveBlock(MapBlock *block)
 {
        DSTACK(__FUNCTION_NAME);
@@ -3109,7 +3209,7 @@ void ServerMap::saveBlock(MapBlock *block)
        if(block->isDummy())
        {
                /*v3s16 p = block->getPos();
-               dstream<<"ServerMap::saveBlock(): WARNING: Not writing dummy block "
+               infostream<<"ServerMap::saveBlock(): WARNING: Not writing dummy block "
                                <<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/
                return;
        }
@@ -3119,20 +3219,27 @@ void ServerMap::saveBlock(MapBlock *block)
        // Get destination
        v3s16 p3d = block->getPos();
        
+       
+#if 0
        v2s16 p2d(p3d.X, p3d.Z);
        std::string sectordir = getSectorDir(p2d);
 
        createDirs(sectordir);
 
-       std::string fullpath = sectordir+"/"+getBlockFilename(p3d);
+       std::string fullpath = sectordir+DIR_DELIM+getBlockFilename(p3d);
        std::ofstream o(fullpath.c_str(), std::ios_base::binary);
        if(o.good() == false)
                throw FileNotGoodException("Cannot open block data");
-
+#endif
        /*
                [0] u8 serialization version
                [1] data
        */
+       
+       verifyDatabase();
+       
+       std::ostringstream o(std::ios_base::binary);
+       
        o.write((char*)&version, 1);
        
        // Write basic data
@@ -3140,7 +3247,23 @@ void ServerMap::saveBlock(MapBlock *block)
        
        // Write extra data stored on disk
        block->serializeDiskExtra(o, version);
-
+       
+       // Write block to database
+       
+       std::string tmp = o.str();
+       const char *bytes = tmp.c_str();
+       
+       if(sqlite3_bind_int64(m_database_write, 1, getBlockAsInteger(p3d)) != SQLITE_OK)
+               infostream<<"WARNING: Block position failed to bind: "<<sqlite3_errmsg(m_database)<<std::endl;
+       if(sqlite3_bind_blob(m_database_write, 2, (void *)bytes, o.tellp(), NULL) != SQLITE_OK) // TODO this mught not be the right length
+               infostream<<"WARNING: Block data failed to bind: "<<sqlite3_errmsg(m_database)<<std::endl;
+       int written = sqlite3_step(m_database_write);
+       if(written != SQLITE_DONE)
+               infostream<<"WARNING: Block failed to save ("<<p3d.X<<", "<<p3d.Y<<", "<<p3d.Z<<") "
+               <<sqlite3_errmsg(m_database)<<std::endl;
+       // Make ready for later reuse
+       sqlite3_reset(m_database_write);
+       
        // We just wrote it to the disk so clear modified flag
        block->resetModified();
 }
@@ -3149,7 +3272,7 @@ void ServerMap::loadBlock(std::string sectordir, std::string blockfile, MapSecto
 {
        DSTACK(__FUNCTION_NAME);
 
-       std::string fullpath = sectordir+"/"+blockfile;
+       std::string fullpath = sectordir+DIR_DELIM+blockfile;
        try{
 
                std::ifstream is(fullpath.c_str(), std::ios_base::binary);
@@ -3201,6 +3324,9 @@ void ServerMap::loadBlock(std::string sectordir, std::string blockfile, MapSecto
                if(version < SER_FMT_VER_HIGHEST || save_after_load)
                {
                        saveBlock(block);
+                       
+                       // Should be in database now, so delete the old file
+                       fs::RecursiveDelete(fullpath);
                }
                
                // We just loaded it from the disk, so it's up-to-date.
@@ -3209,7 +3335,7 @@ void ServerMap::loadBlock(std::string sectordir, std::string blockfile, MapSecto
        }
        catch(SerializationError &e)
        {
-               dstream<<"WARNING: Invalid block data on disk "
+               infostream<<"WARNING: Invalid block data on disk "
                                <<"fullpath="<<fullpath
                                <<" (SerializationError). "
                                <<"what()="<<e.what()
@@ -3221,12 +3347,111 @@ void ServerMap::loadBlock(std::string sectordir, std::string blockfile, MapSecto
        }
 }
 
+void ServerMap::loadBlock(std::string *blob, v3s16 p3d, MapSector *sector, bool save_after_load)
+{
+       DSTACK(__FUNCTION_NAME);
+
+       try {
+               std::istringstream is(*blob, std::ios_base::binary);
+               
+               u8 version = SER_FMT_VER_INVALID;
+               is.read((char*)&version, 1);
+
+               if(is.fail())
+                       throw SerializationError("ServerMap::loadBlock(): Failed"
+                                       " to read MapBlock version");
+
+               /*u32 block_size = MapBlock::serializedLength(version);
+               SharedBuffer<u8> data(block_size);
+               is.read((char*)*data, block_size);*/
+
+               // This will always return a sector because we're the server
+               //MapSector *sector = emergeSector(p2d);
+
+               MapBlock *block = NULL;
+               bool created_new = false;
+               block = sector->getBlockNoCreateNoEx(p3d.Y);
+               if(block == NULL)
+               {
+                       block = sector->createBlankBlockNoInsert(p3d.Y);
+                       created_new = true;
+               }
+               
+               // Read basic data
+               block->deSerialize(is, version);
+
+               // 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);
+               
+               /*
+                       Save blocks loaded in old format in new format
+               */
+
+               if(version < SER_FMT_VER_HIGHEST || save_after_load)
+               {
+                       saveBlock(block);
+               }
+               
+               // We just loaded it from, so it's up-to-date.
+               block->resetModified();
+
+       }
+       catch(SerializationError &e)
+       {
+               infostream<<"WARNING: Invalid block data in database "
+                               <<" (SerializationError). "
+                               <<"what()="<<e.what()
+                               <<std::endl;
+                               //" Ignoring. A new one will be generated.
+               assert(0);
+
+               // TODO: Copy to a backup database.
+       }
+}
+
 MapBlock* ServerMap::loadBlock(v3s16 blockpos)
 {
        DSTACK(__FUNCTION_NAME);
 
        v2s16 p2d(blockpos.X, blockpos.Z);
 
+       if(!loadFromFolders()) {
+               verifyDatabase();
+               
+               if(sqlite3_bind_int64(m_database_read, 1, getBlockAsInteger(blockpos)) != SQLITE_OK)
+                       infostream<<"WARNING: Could not bind block position for load: "
+                               <<sqlite3_errmsg(m_database)<<std::endl;
+               if(sqlite3_step(m_database_read) == SQLITE_ROW) {
+                       /*
+                               Make sure sector is loaded
+                       */
+                       MapSector *sector = createSector(p2d);
+                       
+                       /*
+                               Load block
+                       */
+                       const char * data = (const char *)sqlite3_column_blob(m_database_read, 0);
+                       size_t len = sqlite3_column_bytes(m_database_read, 0);
+                       
+                       std::string datastr(data, len);
+                       
+                       loadBlock(&datastr, blockpos, sector, false);
+
+                       sqlite3_step(m_database_read);
+                       // We should never get more than 1 row, so ok to reset
+                       sqlite3_reset(m_database_read);
+
+                       return getBlockNoCreateNoEx(blockpos);
+               }
+               sqlite3_reset(m_database_read);
+               
+               // Not found in database, try the files
+       }
+
        // The directory layout we're going to load from.
        //  1 - original sectors/xxxxzzzz/
        //  2 - new sectors2/xxx/zzz/
@@ -3273,13 +3498,13 @@ MapBlock* ServerMap::loadBlock(v3s16 blockpos)
        */
 
        std::string blockfilename = getBlockFilename(blockpos);
-       if(fs::PathExists(sectordir+"/"+blockfilename) == false)
+       if(fs::PathExists(sectordir+DIR_DELIM+blockfilename) == false)
                return NULL;
 
        /*
-               Load block
+               Load block and save it to the database
        */
-       loadBlock(sectordir, blockfilename, sector, loadlayout != 2);
+       loadBlock(sectordir, blockfilename, sector, true);
        return getBlockNoCreateNoEx(blockpos);
 }
 
@@ -3306,7 +3531,8 @@ ClientMap::ClientMap(
        m_client(client),
        m_control(control),
        m_camera_position(0,0,0),
-       m_camera_direction(0,0,1)
+       m_camera_direction(0,0,1),
+       m_camera_fov(PI)
 {
        m_camera_mutex.Init();
        assert(m_camera_mutex.IsInitialized());
@@ -3387,6 +3613,35 @@ void ClientMap::OnRegisterSceneNode()
        ISceneNode::OnRegisterSceneNode();
 }
 
+static bool isOccluded(Map *map, v3s16 p0, v3s16 p1, float step, float stepfac,
+               float start_off, float end_off, u32 needed_count)
+{
+       float d0 = (float)BS * p0.getDistanceFrom(p1);
+       v3s16 u0 = p1 - p0;
+       v3f uf = v3f(u0.X, u0.Y, u0.Z) * BS;
+       uf.normalize();
+       v3f p0f = v3f(p0.X, p0.Y, p0.Z) * BS;
+       u32 count = 0;
+       for(float s=start_off; s<d0+end_off; s+=step){
+               v3f pf = p0f + uf * s;
+               v3s16 p = floatToInt(pf, BS);
+               MapNode n = map->getNodeNoEx(p);
+               bool is_transparent = false;
+               ContentFeatures &f = content_features(n);
+               if(f.solidness == 0)
+                       is_transparent = (f.visual_solidness != 2);
+               else
+                       is_transparent = (f.solidness != 2);
+               if(!is_transparent){
+                       count++;
+                       if(count >= needed_count)
+                               return true;
+               }
+               step *= stepfac;
+       }
+       return false;
+}
+
 void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)
 {
        //m_dout<<DTIME<<"Rendering map..."<<std::endl;
@@ -3394,6 +3649,12 @@ void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)
 
        bool is_transparent_pass = pass == scene::ESNRP_TRANSPARENT;
        
+       std::string prefix;
+       if(pass == scene::ESNRP_SOLID)
+               prefix = "CM: solid: ";
+       else
+               prefix = "CM: transparent: ";
+
        /*
                This is called two times per frame, reset on the non-transparent one
        */
@@ -3415,61 +3676,66 @@ void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)
        m_camera_mutex.Lock();
        v3f camera_position = m_camera_position;
        v3f camera_direction = m_camera_direction;
+       f32 camera_fov = m_camera_fov;
        m_camera_mutex.Unlock();
 
        /*
                Get all blocks and draw all visible ones
        */
 
-       v3s16 cam_pos_nodes(
-                       camera_position.X / BS,
-                       camera_position.Y / BS,
-                       camera_position.Z / BS);
-
+       v3s16 cam_pos_nodes = floatToInt(camera_position, BS);
+       
        v3s16 box_nodes_d = m_control.wanted_range * v3s16(1,1,1);
 
        v3s16 p_nodes_min = cam_pos_nodes - box_nodes_d;
        v3s16 p_nodes_max = cam_pos_nodes + box_nodes_d;
 
        // Take a fair amount as we will be dropping more out later
+       // Umm... these additions are a bit strange but they are needed.
        v3s16 p_blocks_min(
-                       p_nodes_min.X / MAP_BLOCKSIZE - 2,
-                       p_nodes_min.Y / MAP_BLOCKSIZE - 2,
-                       p_nodes_min.Z / MAP_BLOCKSIZE - 2);
+                       p_nodes_min.X / MAP_BLOCKSIZE - 3,
+                       p_nodes_min.Y / MAP_BLOCKSIZE - 3,
+                       p_nodes_min.Z / MAP_BLOCKSIZE - 3);
        v3s16 p_blocks_max(
                        p_nodes_max.X / MAP_BLOCKSIZE + 1,
                        p_nodes_max.Y / MAP_BLOCKSIZE + 1,
                        p_nodes_max.Z / MAP_BLOCKSIZE + 1);
        
        u32 vertex_count = 0;
+       u32 meshbuffer_count = 0;
        
        // For limiting number of mesh updates per frame
        u32 mesh_update_count = 0;
        
+       // Number of blocks in rendering range
+       u32 blocks_in_range = 0;
+       // Number of blocks occlusion culled
+       u32 blocks_occlusion_culled = 0;
+       // Number of blocks in rendering range but don't have a mesh
+       u32 blocks_in_range_without_mesh = 0;
+       // Blocks that had mesh that would have been drawn according to
+       // rendering range (if max blocks limit didn't kick in)
        u32 blocks_would_have_drawn = 0;
+       // Blocks that were drawn and had a mesh
        u32 blocks_drawn = 0;
+       // Blocks which had a corresponding meshbuffer for this pass
+       u32 blocks_had_pass_meshbuf = 0;
+       // Blocks from which stuff was actually drawn
+       u32 blocks_without_stuff = 0;
+
+       /*
+               Collect a set of blocks for drawing
+       */
+       
+       core::map<v3s16, MapBlock*> drawset;
 
-       int timecheck_counter = 0;
-       core::map<v2s16, MapSector*>::Iterator si;
-       si = m_sectors.getIterator();
-       for(; si.atEnd() == false; si++)
        {
-               {
-                       timecheck_counter++;
-                       if(timecheck_counter > 50)
-                       {
-                               timecheck_counter = 0;
-                               int time2 = time(0);
-                               if(time2 > time1 + 4)
-                               {
-                                       dstream<<"ClientMap::renderMap(): "
-                                               "Rendering takes ages, returning."
-                                               <<std::endl;
-                                       return;
-                               }
-                       }
-               }
+       ScopeProfiler sp(g_profiler, prefix+"collecting blocks for drawing", SPT_AVG);
 
+       for(core::map<v2s16, MapSector*>::Iterator
+                       si = m_sectors.getIterator();
+                       si.atEnd() == false; si++)
+       {
                MapSector *sector = si.getNode()->getValue();
                v2s16 sp = sector->getPos();
                
@@ -3486,11 +3752,11 @@ void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)
                sector->getBlocks(sectorblocks);
                
                /*
-                       Draw blocks
+                       Loop through blocks in sector
                */
-               
-               u32 sector_blocks_drawn = 0;
 
+               u32 sector_blocks_drawn = 0;
+               
                core::list< MapBlock * >::Iterator i;
                for(i=sectorblocks.begin(); i!=sectorblocks.end(); i++)
                {
@@ -3504,22 +3770,25 @@ void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)
                        float range = 100000 * BS;
                        if(m_control.range_all == false)
                                range = m_control.wanted_range * BS;
-                       
+
                        float d = 0.0;
                        if(isBlockInSight(block->getPos(), camera_position,
-                                       camera_direction, range, &d) == false)
+                                       camera_direction, camera_fov,
+                                       range, &d) == false)
                        {
                                continue;
                        }
 
-                       // Okay, this block will be drawn. Reset usage timer.
-                       block->resetUsageTimer();
-                       
                        // This is ugly (spherical distance limit?)
                        /*if(m_control.range_all == false &&
                                        d - 0.5*BS*MAP_BLOCKSIZE > range)
                                continue;*/
 
+                       blocks_in_range++;
+                       
+                       // This block is in range. Reset usage timer.
+                       block->resetUsageTimer();
+
 #if 1
                        /*
                                Update expired mesh (used for day/night change)
@@ -3537,8 +3806,10 @@ void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)
 
                                // Mesh has not been expired and there is no mesh:
                                // block has no content
-                               if(block->mesh == NULL && mesh_expired == false)
+                               if(block->mesh == NULL && mesh_expired == false){
+                                       blocks_in_range_without_mesh++;
                                        continue;
+                               }
                        }
 
                        f32 faraway = BS*50;
@@ -3567,66 +3838,208 @@ void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)
 
                                mesh_expired = false;
                        }
-                       
 #endif
+
+                       /*
+                               Occlusion culling
+                       */
+
+                       v3s16 cpn = block->getPos() * MAP_BLOCKSIZE;
+                       cpn += v3s16(MAP_BLOCKSIZE/2, MAP_BLOCKSIZE/2, MAP_BLOCKSIZE/2);
+                       float step = BS*1;
+                       float stepfac = 1.1;
+                       float startoff = BS*1;
+                       float endoff = -BS*MAP_BLOCKSIZE*1.42*1.42;
+                       v3s16 spn = cam_pos_nodes + v3s16(0,0,0);
+                       s16 bs2 = MAP_BLOCKSIZE/2 + 1;
+                       u32 needed_count = 1;
+                       if(
+                               isOccluded(this, spn, cpn + v3s16(0,0,0),
+                                               step, stepfac, startoff, endoff, needed_count) &&
+                               isOccluded(this, spn, cpn + v3s16(bs2,bs2,bs2),
+                                               step, stepfac, startoff, endoff, needed_count) &&
+                               isOccluded(this, spn, cpn + v3s16(bs2,bs2,-bs2),
+                                               step, stepfac, startoff, endoff, needed_count) &&
+                               isOccluded(this, spn, cpn + v3s16(bs2,-bs2,bs2),
+                                               step, stepfac, startoff, endoff, needed_count) &&
+                               isOccluded(this, spn, cpn + v3s16(bs2,-bs2,-bs2),
+                                               step, stepfac, startoff, endoff, needed_count) &&
+                               isOccluded(this, spn, cpn + v3s16(-bs2,bs2,bs2),
+                                               step, stepfac, startoff, endoff, needed_count) &&
+                               isOccluded(this, spn, cpn + v3s16(-bs2,bs2,-bs2),
+                                               step, stepfac, startoff, endoff, needed_count) &&
+                               isOccluded(this, spn, cpn + v3s16(-bs2,-bs2,bs2),
+                                               step, stepfac, startoff, endoff, needed_count) &&
+                               isOccluded(this, spn, cpn + v3s16(-bs2,-bs2,-bs2),
+                                               step, stepfac, startoff, endoff, needed_count)
+                       )
+                       {
+                               blocks_occlusion_culled++;
+                               continue;
+                       }
+                       
                        /*
-                               Draw the faces of the block
+                               Ignore if mesh doesn't exist
                        */
                        {
                                JMutexAutoLock lock(block->mesh_mutex);
 
                                scene::SMesh *mesh = block->mesh;
-
-                               if(mesh == NULL)
-                                       continue;
                                
-                               blocks_would_have_drawn++;
-                               if(blocks_drawn >= m_control.wanted_max_blocks
-                                               && m_control.range_all == false
-                                               && d > m_control.wanted_min_range * BS)
+                               if(mesh == NULL){
+                                       blocks_in_range_without_mesh++;
                                        continue;
+                               }
+                       }
+                       
+                       // Limit block count in case of a sudden increase
+                       blocks_would_have_drawn++;
+                       if(blocks_drawn >= m_control.wanted_max_blocks
+                                       && m_control.range_all == false
+                                       && d > m_control.wanted_min_range * BS)
+                               continue;
+                       
+                       // Add to set
+                       drawset[block->getPos()] = block;
+                       
+                       sector_blocks_drawn++;
+                       blocks_drawn++;
 
-                               blocks_drawn++;
-                               sector_blocks_drawn++;
+               } // foreach sectorblocks
+
+               if(sector_blocks_drawn != 0)
+                       m_last_drawn_sectors[sp] = true;
+       }
+       } // ScopeProfiler
+       
+       /*
+               Draw the selected MapBlocks
+       */
 
-                               u32 c = mesh->getMeshBufferCount();
+       {
+       ScopeProfiler sp(g_profiler, prefix+"drawing blocks", SPT_AVG);
 
-                               for(u32 i=0; i<c; i++)
+       int timecheck_counter = 0;
+       for(core::map<v3s16, MapBlock*>::Iterator
+                       i = drawset.getIterator();
+                       i.atEnd() == false; i++)
+       {
+               {
+                       timecheck_counter++;
+                       if(timecheck_counter > 50)
+                       {
+                               timecheck_counter = 0;
+                               int time2 = time(0);
+                               if(time2 > time1 + 4)
                                {
-                                       scene::IMeshBuffer *buf = mesh->getMeshBuffer(i);
-                                       const video::SMaterial& material = buf->getMaterial();
-                                       video::IMaterialRenderer* rnd =
-                                                       driver->getMaterialRenderer(material.MaterialType);
-                                       bool transparent = (rnd && rnd->isTransparent());
-                                       // Render transparent on transparent pass and likewise.
-                                       if(transparent == is_transparent_pass)
-                                       {
-                                               /*
-                                                       This *shouldn't* hurt too much because Irrlicht
-                                                       doesn't change opengl textures if the old
-                                                       material is set again.
-                                               */
-                                               driver->setMaterial(buf->getMaterial());
-                                               driver->drawMeshBuffer(buf);
-                                               vertex_count += buf->getVertexCount();
-                                       }
+                                       infostream<<"ClientMap::renderMap(): "
+                                               "Rendering takes ages, returning."
+                                               <<std::endl;
+                                       return;
                                }
                        }
-               } // foreach sectorblocks
+               }
+               
+               MapBlock *block = i.getNode()->getValue();
 
-               if(sector_blocks_drawn != 0)
+               /*
+                       Draw the faces of the block
+               */
                {
-                       m_last_drawn_sectors[sp] = true;
+                       JMutexAutoLock lock(block->mesh_mutex);
+
+                       scene::SMesh *mesh = block->mesh;
+                       assert(mesh);
+                       
+                       u32 c = mesh->getMeshBufferCount();
+                       bool stuff_actually_drawn = false;
+                       for(u32 i=0; i<c; i++)
+                       {
+                               scene::IMeshBuffer *buf = mesh->getMeshBuffer(i);
+                               const video::SMaterial& material = buf->getMaterial();
+                               video::IMaterialRenderer* rnd =
+                                               driver->getMaterialRenderer(material.MaterialType);
+                               bool transparent = (rnd && rnd->isTransparent());
+                               // Render transparent on transparent pass and likewise.
+                               if(transparent == is_transparent_pass)
+                               {
+                                       if(buf->getVertexCount() == 0)
+                                               errorstream<<"Block ["<<analyze_block(block)
+                                                               <<"] contains an empty meshbuf"<<std::endl;
+                                       /*
+                                               This *shouldn't* hurt too much because Irrlicht
+                                               doesn't change opengl textures if the old
+                                               material has the same texture.
+                                       */
+                                       driver->setMaterial(buf->getMaterial());
+                                       driver->drawMeshBuffer(buf);
+                                       vertex_count += buf->getVertexCount();
+                                       meshbuffer_count++;
+                                       stuff_actually_drawn = true;
+                               }
+                       }
+                       if(stuff_actually_drawn)
+                               blocks_had_pass_meshbuf++;
+                       else
+                               blocks_without_stuff++;
                }
        }
+       } // ScopeProfiler
+       
+       // Log only on solid pass because values are the same
+       if(pass == scene::ESNRP_SOLID){
+               g_profiler->avg("CM: blocks in range", blocks_in_range);
+               g_profiler->avg("CM: blocks occlusion culled", blocks_occlusion_culled);
+               if(blocks_in_range != 0)
+                       g_profiler->avg("CM: blocks in range without mesh (frac)",
+                                       (float)blocks_in_range_without_mesh/blocks_in_range);
+               g_profiler->avg("CM: blocks drawn", blocks_drawn);
+       }
        
+       g_profiler->avg(prefix+"vertices drawn", vertex_count);
+       if(blocks_had_pass_meshbuf != 0)
+               g_profiler->avg(prefix+"meshbuffers per block",
+                               (float)meshbuffer_count / (float)blocks_had_pass_meshbuf);
+       if(blocks_drawn != 0)
+               g_profiler->avg(prefix+"empty blocks (frac)",
+                               (float)blocks_without_stuff / blocks_drawn);
+
        m_control.blocks_drawn = blocks_drawn;
        m_control.blocks_would_have_drawn = blocks_would_have_drawn;
 
-       /*dstream<<"renderMap(): is_transparent_pass="<<is_transparent_pass
+       /*infostream<<"renderMap(): is_transparent_pass="<<is_transparent_pass
                        <<", rendered "<<vertex_count<<" vertices."<<std::endl;*/
 }
 
+void ClientMap::renderPostFx()
+{
+       // Sadly ISceneManager has no "post effects" render pass, in that case we
+       // could just register for that and handle it in renderMap().
+
+       m_camera_mutex.Lock();
+       v3f camera_position = m_camera_position;
+       m_camera_mutex.Unlock();
+
+       MapNode n = getNodeNoEx(floatToInt(camera_position, BS));
+
+       // - If the player is in a solid node, make everything black.
+       // - If the player is in liquid, draw a semi-transparent overlay.
+       ContentFeatures& features = content_features(n);
+       video::SColor post_effect_color = features.post_effect_color;
+       if(features.solidness == 2 && g_settings->getBool("free_move") == false)
+       {
+               post_effect_color = video::SColor(255, 0, 0, 0);
+       }
+       if (post_effect_color.getAlpha() != 0)
+       {
+               // Draw a full-screen rectangle
+               video::IVideoDriver* driver = SceneManager->getVideoDriver();
+               v2u32 ss = driver->getScreenSize();
+               core::rect<s32> rect(0,0, ss.X, ss.Y);
+               driver->draw2DRectangle(post_effect_color, rect);
+       }
+}
+
 bool ClientMap::setTempMod(v3s16 p, NodeMod mod,
                core::map<v3s16, MapBlock*> *affected_blocks)
 {
@@ -3844,7 +4257,7 @@ MapVoxelManipulator::MapVoxelManipulator(Map *map)
 
 MapVoxelManipulator::~MapVoxelManipulator()
 {
-       /*dstream<<"MapVoxelManipulator: blocks: "<<m_loaded_blocks.size()
+       /*infostream<<"MapVoxelManipulator: blocks: "<<m_loaded_blocks.size()
                        <<std::endl;*/
 }
 
@@ -3876,11 +4289,11 @@ void MapVoxelManipulator::emerge(VoxelArea a, s32 caller_id)
                {
                        TimeTaker timer1("emerge load", &emerge_load_time);
 
-                       /*dstream<<"Loading block (caller_id="<<caller_id<<")"
+                       /*infostream<<"Loading block (caller_id="<<caller_id<<")"
                                        <<" ("<<p.X<<","<<p.Y<<","<<p.Z<<")"
                                        <<" wanted area: ";
-                       a.print(dstream);
-                       dstream<<std::endl;*/
+                       a.print(infostream);
+                       infostream<<std::endl;*/
                        
                        MapBlock *block = m_map->getBlockNoCreate(p);
                        if(block->isDummy())
@@ -3908,7 +4321,7 @@ void MapVoxelManipulator::emerge(VoxelArea a, s32 caller_id)
                m_loaded_blocks.insert(p, !block_data_inexistent);
        }
 
-       //dstream<<"emerge done"<<std::endl;
+       //infostream<<"emerge done"<<std::endl;
 }
 
 /*
@@ -3924,7 +4337,7 @@ void MapVoxelManipulator::blitBack
        
        //TimeTaker timer1("blitBack");
 
-       /*dstream<<"blitBack(): m_loaded_blocks.size()="
+       /*infostream<<"blitBack(): m_loaded_blocks.size()="
                        <<m_loaded_blocks.size()<<std::endl;*/
        
        /*
@@ -4013,10 +4426,10 @@ void ManualMapVoxelManipulator::initialEmerge(
        u32 size_MB = block_area_nodes.getVolume()*4/1000000;
        if(size_MB >= 1)
        {
-               dstream<<"initialEmerge: area: ";
-               block_area_nodes.print(dstream);
-               dstream<<" ("<<size_MB<<"MB)";
-               dstream<<std::endl;
+               infostream<<"initialEmerge: area: ";
+               block_area_nodes.print(infostream);
+               infostream<<" ("<<size_MB<<"MB)";
+               infostream<<std::endl;
        }
 
        addArea(block_area_nodes);
@@ -4079,14 +4492,20 @@ void ManualMapVoxelManipulator::blitBackAll(
                        i = m_loaded_blocks.getIterator();
                        i.atEnd() == false; i++)
        {
+               v3s16 p = i.getNode()->getKey();
                bool existed = i.getNode()->getValue();
                if(existed == false)
+               {
+                       // The Great Bug was found using this
+                       /*infostream<<"ManualMapVoxelManipulator::blitBackAll: "
+                                       <<"Inexistent ("<<p.X<<","<<p.Y<<","<<p.Z<<")"
+                                       <<std::endl;*/
                        continue;
-               v3s16 p = i.getNode()->getKey();
+               }
                MapBlock *block = m_map->getBlockNoCreateNoEx(p);
                if(block == NULL)
                {
-                       dstream<<"WARNING: "<<__FUNCTION_NAME
+                       infostream<<"WARNING: "<<__FUNCTION_NAME
                                        <<": got NULL block "
                                        <<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
                                        <<std::endl;