[minetest.git] / src / environment.cpp

/*
Minetest-c55
Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include <set>
#include <list>
#include <map>
#include "environment.h"
#include "filesys.h"
#include "porting.h"
#include "collision.h"
#include "content_mapnode.h"
#include "mapblock.h"
#include "serverobject.h"
#include "content_sao.h"
#include "mapgen.h"
#include "settings.h"
#include "log.h"
#include "profiler.h"
#include "scriptapi.h"
#include "nodedef.h"
#include "nodemetadata.h"
#include "main.h" // For g_settings, g_profiler
#include "gamedef.h"

#define PP(x) "("<<(x).X<<","<<(x).Y<<","<<(x).Z<<")"

Environment::Environment():
        m_time_of_day(9000)
{
}

Environment::~Environment()
{
        // Deallocate players
        for(core::list<Player*>::Iterator i = m_players.begin();
                        i != m_players.end(); i++)
        {
                delete (*i);
        }
}

void Environment::addPlayer(Player *player)
{
        DSTACK(__FUNCTION_NAME);
        /*
                Check that peer_ids are unique.
                Also check that names are unique.
                Exception: there can be multiple players with peer_id=0
        */
        // If peer id is non-zero, it has to be unique.
        if(player->peer_id != 0)
                assert(getPlayer(player->peer_id) == NULL);
        // Name has to be unique.
        assert(getPlayer(player->getName()) == NULL);
        // Add.
        m_players.push_back(player);
}

void Environment::removePlayer(u16 peer_id)
{
        DSTACK(__FUNCTION_NAME);
re_search:
        for(core::list<Player*>::Iterator i = m_players.begin();
                        i != m_players.end(); i++)
        {
                Player *player = *i;
                if(player->peer_id != peer_id)
                        continue;
                
                delete player;
                m_players.erase(i);
                // See if there is an another one
                // (shouldn't be, but just to be sure)
                goto re_search;
        }
}

Player * Environment::getPlayer(u16 peer_id)
{
        for(core::list<Player*>::Iterator i = m_players.begin();
                        i != m_players.end(); i++)
        {
                Player *player = *i;
                if(player->peer_id == peer_id)
                        return player;
        }
        return NULL;
}

Player * Environment::getPlayer(const char *name)
{
        for(core::list<Player*>::Iterator i = m_players.begin();
                        i != m_players.end(); i++)
        {
                Player *player = *i;
                if(strcmp(player->getName(), name) == 0)
                        return player;
        }
        return NULL;
}

Player * Environment::getRandomConnectedPlayer()
{
        core::list<Player*> connected_players = getPlayers(true);
        u32 chosen_one = myrand() % connected_players.size();
        u32 j = 0;
        for(core::list<Player*>::Iterator
                        i = connected_players.begin();
                        i != connected_players.end(); i++)
        {
                if(j == chosen_one)
                {
                        Player *player = *i;
                        return player;
                }
                j++;
        }
        return NULL;
}

Player * Environment::getNearestConnectedPlayer(v3f pos)
{
        core::list<Player*> connected_players = getPlayers(true);
        f32 nearest_d = 0;
        Player *nearest_player = NULL;
        for(core::list<Player*>::Iterator
                        i = connected_players.begin();
                        i != connected_players.end(); i++)
        {
                Player *player = *i;
                f32 d = player->getPosition().getDistanceFrom(pos);
                if(d < nearest_d || nearest_player == NULL)
                {
                        nearest_d = d;
                        nearest_player = player;
                }
        }
        return nearest_player;
}

core::list<Player*> Environment::getPlayers()
{
        return m_players;
}

core::list<Player*> Environment::getPlayers(bool ignore_disconnected)
{
        core::list<Player*> newlist;
        for(core::list<Player*>::Iterator
                        i = m_players.begin();
                        i != m_players.end(); i++)
        {
                Player *player = *i;
                
                if(ignore_disconnected)
                {
                        // Ignore disconnected players
                        if(player->peer_id == 0)
                                continue;
                }

                newlist.push_back(player);
        }
        return newlist;
}

void Environment::printPlayers(std::ostream &o)
{
        o<<"Players in environment:"<<std::endl;
        for(core::list<Player*>::Iterator i = m_players.begin();
                        i != m_players.end(); i++)
        {
                Player *player = *i;
                o<<"Player peer_id="<<player->peer_id<<std::endl;
        }
}

/*void Environment::setDayNightRatio(u32 r)
{
        getDayNightRatio() = r;
}*/

u32 Environment::getDayNightRatio()
{
        //return getDayNightRatio();
        return time_to_daynight_ratio(m_time_of_day);
}

/*
        ActiveBlockList
*/

void fillRadiusBlock(v3s16 p0, s16 r, core::map<v3s16, bool> &list)
{
        v3s16 p;
        for(p.X=p0.X-r; p.X<=p0.X+r; p.X++)
        for(p.Y=p0.Y-r; p.Y<=p0.Y+r; p.Y++)
        for(p.Z=p0.Z-r; p.Z<=p0.Z+r; p.Z++)
        {
                // Set in list
                list[p] = true;
        }
}

void ActiveBlockList::update(core::list<v3s16> &active_positions,
                s16 radius,
                core::map<v3s16, bool> &blocks_removed,
                core::map<v3s16, bool> &blocks_added)
{
        /*
                Create the new list
        */
        core::map<v3s16, bool> newlist;
        for(core::list<v3s16>::Iterator i = active_positions.begin();
                        i != active_positions.end(); i++)
        {
                fillRadiusBlock(*i, radius, newlist);
        }

        /*
                Find out which blocks on the old list are not on the new list
        */
        // Go through old list
        for(core::map<v3s16, bool>::Iterator i = m_list.getIterator();
                        i.atEnd()==false; i++)
        {
                v3s16 p = i.getNode()->getKey();
                // If not on new list, it's been removed
                if(newlist.find(p) == NULL)
                        blocks_removed.insert(p, true);
        }

        /*
                Find out which blocks on the new list are not on the old list
        */
        // Go through new list
        for(core::map<v3s16, bool>::Iterator i = newlist.getIterator();
                        i.atEnd()==false; i++)
        {
                v3s16 p = i.getNode()->getKey();
                // If not on old list, it's been added
                if(m_list.find(p) == NULL)
                        blocks_added.insert(p, true);
        }

        /*
                Update m_list
        */
        m_list.clear();
        for(core::map<v3s16, bool>::Iterator i = newlist.getIterator();
                        i.atEnd()==false; i++)
        {
                v3s16 p = i.getNode()->getKey();
                m_list.insert(p, true);
        }
}

/*
        ServerEnvironment
*/

ServerEnvironment::ServerEnvironment(ServerMap *map, lua_State *L,
                IGameDef *gamedef, IBackgroundBlockEmerger *emerger):
        m_map(map),
        m_lua(L),
        m_gamedef(gamedef),
        m_emerger(emerger),
        m_random_spawn_timer(3),
        m_send_recommended_timer(0),
        m_game_time(0),
        m_game_time_fraction_counter(0)
{
}

ServerEnvironment::~ServerEnvironment()
{
        // Clear active block list.
        // This makes the next one delete all active objects.
        m_active_blocks.clear();

        // Convert all objects to static and delete the active objects
        deactivateFarObjects(true);

        // Drop/delete map
        m_map->drop();

        // Delete ActiveBlockModifiers
        for(core::list<ABMWithState>::Iterator
                        i = m_abms.begin(); i != m_abms.end(); i++){
                delete i->abm;
        }
}

void ServerEnvironment::serializePlayers(const std::string &savedir)
{
        std::string players_path = savedir + "/players";
        fs::CreateDir(players_path);

        core::map<Player*, bool> saved_players;

        std::vector<fs::DirListNode> player_files = fs::GetDirListing(players_path);
        for(u32 i=0; i<player_files.size(); i++)
        {
                if(player_files[i].dir)
                        continue;
                
                // Full path to this file
                std::string path = players_path + "/" + player_files[i].name;

                //infostream<<"Checking player file "<<path<<std::endl;

                // Load player to see what is its name
                ServerRemotePlayer testplayer(this);
                {
                        // Open file and deserialize
                        std::ifstream is(path.c_str(), std::ios_base::binary);
                        if(is.good() == false)
                        {
                                infostream<<"Failed to read "<<path<<std::endl;
                                continue;
                        }
                        testplayer.deSerialize(is);
                }

                //infostream<<"Loaded test player with name "<<testplayer.getName()<<std::endl;
                
                // Search for the player
                std::string playername = testplayer.getName();
                Player *player = getPlayer(playername.c_str());
                if(player == NULL)
                {
                        infostream<<"Didn't find matching player, ignoring file "<<path<<std::endl;
                        continue;
                }

                //infostream<<"Found matching player, overwriting."<<std::endl;

                // OK, found. Save player there.
                {
                        // Open file and serialize
                        std::ofstream os(path.c_str(), std::ios_base::binary);
                        if(os.good() == false)
                        {
                                infostream<<"Failed to overwrite "<<path<<std::endl;
                                continue;
                        }
                        player->serialize(os);
                        saved_players.insert(player, true);
                }
        }

        for(core::list<Player*>::Iterator i = m_players.begin();
                        i != m_players.end(); i++)
        {
                Player *player = *i;
                if(saved_players.find(player) != NULL)
                {
                        /*infostream<<"Player "<<player->getName()
                                        <<" was already saved."<<std::endl;*/
                        continue;
                }
                std::string playername = player->getName();
                // Don't save unnamed player
                if(playername == "")
                {
                        //infostream<<"Not saving unnamed player."<<std::endl;
                        continue;
                }
                /*
                        Find a sane filename
                */
                if(string_allowed(playername, PLAYERNAME_ALLOWED_CHARS) == false)
                        playername = "player";
                std::string path = players_path + "/" + playername;
                bool found = false;
                for(u32 i=0; i<1000; i++)
                {
                        if(fs::PathExists(path) == false)
                        {
                                found = true;
                                break;
                        }
                        path = players_path + "/" + playername + itos(i);
                }
                if(found == false)
                {
                        infostream<<"Didn't find free file for player"<<std::endl;
                        continue;
                }

                {
                        /*infostream<<"Saving player "<<player->getName()<<" to "
                                        <<path<<std::endl;*/
                        // Open file and serialize
                        std::ofstream os(path.c_str(), std::ios_base::binary);
                        if(os.good() == false)
                        {
                                infostream<<"Failed to overwrite "<<path<<std::endl;
                                continue;
                        }
                        player->serialize(os);
                        saved_players.insert(player, true);
                }
        }

        //infostream<<"Saved "<<saved_players.size()<<" players."<<std::endl;
}

void ServerEnvironment::deSerializePlayers(const std::string &savedir)
{
        std::string players_path = savedir + "/players";

        core::map<Player*, bool> saved_players;

        std::vector<fs::DirListNode> player_files = fs::GetDirListing(players_path);
        for(u32 i=0; i<player_files.size(); i++)
        {
                if(player_files[i].dir)
                        continue;
                
                // Full path to this file
                std::string path = players_path + "/" + player_files[i].name;

                infostream<<"Checking player file "<<path<<std::endl;

                // Load player to see what is its name
                ServerRemotePlayer testplayer(this);
                {
                        // Open file and deserialize
                        std::ifstream is(path.c_str(), std::ios_base::binary);
                        if(is.good() == false)
                        {
                                infostream<<"Failed to read "<<path<<std::endl;
                                continue;
                        }
                        testplayer.deSerialize(is);
                }

                if(!string_allowed(testplayer.getName(), PLAYERNAME_ALLOWED_CHARS))
                {
                        infostream<<"Not loading player with invalid name: "
                                        <<testplayer.getName()<<std::endl;
                }

                infostream<<"Loaded test player with name "<<testplayer.getName()
                                <<std::endl;
                
                // Search for the player
                std::string playername = testplayer.getName();
                Player *player = getPlayer(playername.c_str());
                bool newplayer = false;
                if(player == NULL)
                {
                        infostream<<"Is a new player"<<std::endl;
                        player = new ServerRemotePlayer(this);
                        newplayer = true;
                }

                // Load player
                {
                        infostream<<"Reading player "<<testplayer.getName()<<" from "
                                        <<path<<std::endl;
                        // Open file and deserialize
                        std::ifstream is(path.c_str(), std::ios_base::binary);
                        if(is.good() == false)
                        {
                                infostream<<"Failed to read "<<path<<std::endl;
                                continue;
                        }
                        player->deSerialize(is);
                }

                if(newplayer)
                        addPlayer(player);
        }
}

void ServerEnvironment::saveMeta(const std::string &savedir)
{
        std::string path = savedir + "/env_meta.txt";

        // Open file and serialize
        std::ofstream os(path.c_str(), std::ios_base::binary);
        if(os.good() == false)
        {
                infostream<<"ServerEnvironment::saveMeta(): Failed to open "
                                <<path<<std::endl;
                throw SerializationError("Couldn't save env meta");
        }

        Settings args;
        args.setU64("game_time", m_game_time);
        args.setU64("time_of_day", getTimeOfDay());
        args.writeLines(os);
        os<<"EnvArgsEnd\n";
}

void ServerEnvironment::loadMeta(const std::string &savedir)
{
        std::string path = savedir + "/env_meta.txt";

        // Open file and deserialize
        std::ifstream is(path.c_str(), std::ios_base::binary);
        if(is.good() == false)
        {
                infostream<<"ServerEnvironment::loadMeta(): Failed to open "
                                <<path<<std::endl;
                throw SerializationError("Couldn't load env meta");
        }

        Settings args;
        
        for(;;)
        {
                if(is.eof())
                        throw SerializationError
                                        ("ServerEnvironment::loadMeta(): EnvArgsEnd not found");
                std::string line;
                std::getline(is, line);
                std::string trimmedline = trim(line);
                if(trimmedline == "EnvArgsEnd")
                        break;
                args.parseConfigLine(line);
        }
        
        try{
                m_game_time = args.getU64("game_time");
        }catch(SettingNotFoundException &e){
                // Getting this is crucial, otherwise timestamps are useless
                throw SerializationError("Couldn't load env meta game_time");
        }

        try{
                m_time_of_day = args.getU64("time_of_day");
        }catch(SettingNotFoundException &e){
                // This is not as important
                m_time_of_day = 9000;
        }
}

struct ActiveABM
{
        ActiveBlockModifier *abm;
        int chance;
};

class ABMHandler
{
private:
        ServerEnvironment *m_env;
        std::map<content_t, std::list<ActiveABM> > m_aabms;
public:
        ABMHandler(core::list<ABMWithState> &abms,
                        float dtime_s, ServerEnvironment *env,
                        bool use_timers):
                m_env(env)
        {
                if(dtime_s < 0.001)
                        return;
                INodeDefManager *ndef = env->getGameDef()->ndef();
                for(core::list<ABMWithState>::Iterator
                                i = abms.begin(); i != abms.end(); i++){
                        ActiveBlockModifier *abm = i->abm;
                        float trigger_interval = abm->getTriggerInterval();
                        if(trigger_interval < 0.001)
                                trigger_interval = 0.001;
                        if(use_timers){
                                i->timer += dtime_s;
                                if(i->timer < trigger_interval)
                                        continue;
                                i->timer -= trigger_interval;
                        }
                        ActiveABM aabm;
                        aabm.abm = abm;
                        float intervals = dtime_s / trigger_interval;
                        float chance = abm->getTriggerChance();
                        if(chance == 0)
                                chance = 1;
                        aabm.chance = 1.0 / pow((float)1.0/chance, (float)intervals);
                        if(aabm.chance == 0)
                                aabm.chance = 1;
                        std::set<std::string> contents_s = abm->getTriggerContents();
                        for(std::set<std::string>::iterator
                                        i = contents_s.begin(); i != contents_s.end(); i++){
                                content_t c = ndef->getId(*i);
                                if(c == CONTENT_IGNORE)
                                        continue;
                                std::map<content_t, std::list<ActiveABM> >::iterator j;
                                j = m_aabms.find(c);
                                if(j == m_aabms.end()){
                                        std::list<ActiveABM> aabmlist;
                                        m_aabms[c] = aabmlist;
                                        j = m_aabms.find(c);
                                }
                                j->second.push_back(aabm);
                        }
                }
        }
        void apply(MapBlock *block)
        {
                if(m_aabms.empty())
                        return;

                ServerMap *map = &m_env->getServerMap();
                // Find out how many objects the block contains
                u32 active_object_count = block->m_static_objects.m_active.size();
                // Find out how many objects this and all the neighbors contain
                u32 active_object_count_wider = 0;
                for(s16 x=-1; x<=1; x++)
                for(s16 y=-1; y<=1; y++)
                for(s16 z=-1; z<=1; z++)
                {
                        MapBlock *block2 = map->getBlockNoCreateNoEx(
                                        block->getPos() + v3s16(x,y,z));
                        if(block2==NULL)
                                continue;
                        active_object_count_wider +=
                                        block2->m_static_objects.m_active.size()
                                        + block2->m_static_objects.m_stored.size();
                }

                v3s16 p0;
                for(p0.X=0; p0.X<MAP_BLOCKSIZE; p0.X++)
                for(p0.Y=0; p0.Y<MAP_BLOCKSIZE; p0.Y++)
                for(p0.Z=0; p0.Z<MAP_BLOCKSIZE; p0.Z++)
                {
                        MapNode n = block->getNodeNoEx(p0);
                        content_t c = n.getContent();
                        v3s16 p = p0 + block->getPosRelative();

                        std::map<content_t, std::list<ActiveABM> >::iterator j;
                        j = m_aabms.find(c);
                        if(j == m_aabms.end())
                                continue;

                        for(std::list<ActiveABM>::iterator
                                        i = j->second.begin(); i != j->second.end(); i++){
                                if(myrand() % i->chance != 0)
                                        continue;
                                // Call all the trigger variations
                                i->abm->trigger(m_env, p, n);
                                i->abm->trigger(m_env, p, n,
                                                active_object_count, active_object_count_wider);
                        }
                }
        }
};

void ServerEnvironment::activateBlock(MapBlock *block, u32 additional_dtime)
{
        // Get time difference
        u32 dtime_s = 0;
        u32 stamp = block->getTimestamp();
        if(m_game_time > stamp && stamp != BLOCK_TIMESTAMP_UNDEFINED)
                dtime_s = m_game_time - block->getTimestamp();
        dtime_s += additional_dtime;

        /*infostream<<"ServerEnvironment::activateBlock(): block timestamp: "
                        <<stamp<<", game time: "<<m_game_time<<std::endl;*/

        // Set current time as timestamp
        block->setTimestampNoChangedFlag(m_game_time);

        /*infostream<<"ServerEnvironment::activateBlock(): block is "
                        <<dtime_s<<" seconds old."<<std::endl;*/
        
        // Activate stored objects
        activateObjects(block);

        // Run node metadata
        bool changed = block->m_node_metadata->step((float)dtime_s);
        if(changed)
        {
                MapEditEvent event;
                event.type = MEET_BLOCK_NODE_METADATA_CHANGED;
                event.p = block->getPos();
                m_map->dispatchEvent(&event);

                block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                "node metadata modified in activateBlock");
        }

        /* Handle ActiveBlockModifiers */
        ABMHandler abmhandler(m_abms, dtime_s, this, false);
        abmhandler.apply(block);
}

void ServerEnvironment::addActiveBlockModifier(ActiveBlockModifier *abm)
{
        m_abms.push_back(ABMWithState(abm));
}

void ServerEnvironment::clearAllObjects()
{
        infostream<<"ServerEnvironment::clearAllObjects(): "
                        <<"Removing all active objects"<<std::endl;
        core::list<u16> objects_to_remove;
        for(core::map<u16, ServerActiveObject*>::Iterator
                        i = m_active_objects.getIterator();
                        i.atEnd()==false; i++)
        {
                ServerActiveObject* obj = i.getNode()->getValue();
                u16 id = i.getNode()->getKey();         
                v3f objectpos = obj->getBasePosition(); 
                // Delete static object if block is loaded
                if(obj->m_static_exists){
                        MapBlock *block = m_map->getBlockNoCreateNoEx(obj->m_static_block);
                        if(block){
                                block->m_static_objects.remove(id);
                                block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                                "clearAllObjects");
                                obj->m_static_exists = false;
                        }
                }
                // If known by some client, don't delete immediately
                if(obj->m_known_by_count > 0){
                        obj->m_pending_deactivation = true;
                        obj->m_removed = true;
                        continue;
                }
                // Deregister in scripting api
                scriptapi_rm_object_reference(m_lua, obj);
                // Delete active object
                delete obj;
                // Id to be removed from m_active_objects
                objects_to_remove.push_back(id);
        }
        // Remove references from m_active_objects
        for(core::list<u16>::Iterator i = objects_to_remove.begin();
                        i != objects_to_remove.end(); i++)
        {
                m_active_objects.remove(*i);
        }

        core::list<v3s16> loadable_blocks;
        infostream<<"ServerEnvironment::clearAllObjects(): "
                        <<"Listing all loadable blocks"<<std::endl;
        m_map->listAllLoadableBlocks(loadable_blocks);
        infostream<<"ServerEnvironment::clearAllObjects(): "
                        <<"Done listing all loadable blocks: "
                        <<loadable_blocks.size()
                        <<", now clearing"<<std::endl;
        u32 report_interval = loadable_blocks.size() / 10;
        u32 num_blocks_checked = 0;
        u32 num_blocks_cleared = 0;
        u32 num_objs_cleared = 0;
        for(core::list<v3s16>::Iterator i = loadable_blocks.begin();
                        i != loadable_blocks.end(); i++)
        {
                v3s16 p = *i;
                MapBlock *block = m_map->emergeBlock(p, false);
                if(!block){
                        errorstream<<"ServerEnvironment::clearAllObjects(): "
                                        <<"Failed to emerge block "<<PP(p)<<std::endl;
                        continue;
                }
                u32 num_stored = block->m_static_objects.m_stored.size();
                u32 num_active = block->m_static_objects.m_active.size();
                if(num_stored != 0 || num_active != 0){
                        block->m_static_objects.m_stored.clear();
                        block->m_static_objects.m_active.clear();
                        block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                        "clearAllObjects");
                        num_objs_cleared += num_stored + num_active;
                        num_blocks_cleared++;
                }
                num_blocks_checked++;

                if(num_blocks_checked % report_interval == 0){
                        float percent = 100.0 * (float)num_blocks_checked /
                                        loadable_blocks.size();
                        infostream<<"ServerEnvironment::clearAllObjects(): "
                                        <<"Cleared "<<num_objs_cleared<<" objects"
                                        <<" in "<<num_blocks_cleared<<" blocks ("
                                        <<percent<<"%)"<<std::endl;
                }
        }
        infostream<<"ServerEnvironment::clearAllObjects(): "
                        <<"Finished: Cleared "<<num_objs_cleared<<" objects"
                        <<" in "<<num_blocks_cleared<<" blocks"<<std::endl;
}

void ServerEnvironment::step(float dtime)
{
        DSTACK(__FUNCTION_NAME);
        
        //TimeTaker timer("ServerEnv step");

        // Get some settings
        bool footprints = g_settings->getBool("footprints");

        /*
                Increment game time
        */
        {
                m_game_time_fraction_counter += dtime;
                u32 inc_i = (u32)m_game_time_fraction_counter;
                m_game_time += inc_i;
                m_game_time_fraction_counter -= (float)inc_i;
        }
        
        /*
                Handle players
        */
        {
                ScopeProfiler sp(g_profiler, "SEnv: handle players avg", SPT_AVG);
                for(core::list<Player*>::Iterator i = m_players.begin();
                                i != m_players.end(); i++)
                {
                        Player *player = *i;
                        
                        // Ignore disconnected players
                        if(player->peer_id == 0)
                                continue;

                        v3f playerpos = player->getPosition();
                        
                        // Move
                        player->move(dtime, *m_map, 100*BS);
                        
                        /*
                                Add footsteps to grass
                        */
                        if(footprints)
                        {
                                // Get node that is at BS/4 under player
                                v3s16 bottompos = floatToInt(playerpos + v3f(0,-BS/4,0), BS);
                                try{
                                        MapNode n = m_map->getNode(bottompos);
                                        if(n.getContent() == LEGN(m_gamedef->ndef(), "CONTENT_GRASS"))
                                        {
                                                n.setContent(LEGN(m_gamedef->ndef(), "CONTENT_GRASS_FOOTSTEPS"));
                                                m_map->setNode(bottompos, n);
                                        }
                                }
                                catch(InvalidPositionException &e)
                                {
                                }
                        }
                }
        }

        /*
                Manage active block list
        */
        if(m_active_blocks_management_interval.step(dtime, 2.0))
        {
                ScopeProfiler sp(g_profiler, "SEnv: manage act. block list avg /2s", SPT_AVG);
                /*
                        Get player block positions
                */
                core::list<v3s16> players_blockpos;
                for(core::list<Player*>::Iterator
                                i = m_players.begin();
                                i != m_players.end(); i++)
                {
                        Player *player = *i;
                        // Ignore disconnected players
                        if(player->peer_id == 0)
                                continue;
                        v3s16 blockpos = getNodeBlockPos(
                                        floatToInt(player->getPosition(), BS));
                        players_blockpos.push_back(blockpos);
                }
                
                /*
                        Update list of active blocks, collecting changes
                */
                const s16 active_block_range = g_settings->getS16("active_block_range");
                core::map<v3s16, bool> blocks_removed;
                core::map<v3s16, bool> blocks_added;
                m_active_blocks.update(players_blockpos, active_block_range,
                                blocks_removed, blocks_added);

                /*
                        Handle removed blocks
                */

                // Convert active objects that are no more in active blocks to static
                deactivateFarObjects(false);
                
                for(core::map<v3s16, bool>::Iterator
                                i = blocks_removed.getIterator();
                                i.atEnd()==false; i++)
                {
                        v3s16 p = i.getNode()->getKey();

                        /*infostream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
                                        <<") became inactive"<<std::endl;*/
                        
                        MapBlock *block = m_map->getBlockNoCreateNoEx(p);
                        if(block==NULL)
                                continue;
                        
                        // Set current time as timestamp (and let it set ChangedFlag)
                        block->setTimestamp(m_game_time);
                }

                /*
                        Handle added blocks
                */

                for(core::map<v3s16, bool>::Iterator
                                i = blocks_added.getIterator();
                                i.atEnd()==false; i++)
                {
                        v3s16 p = i.getNode()->getKey();
                        
                        /*infostream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
                                        <<") became active"<<std::endl;*/

                        MapBlock *block = m_map->getBlockNoCreateNoEx(p);
                        if(block==NULL){
                                // Block needs to be fetched first
                                m_emerger->queueBlockEmerge(p, false);
                                m_active_blocks.m_list.remove(p);
                                continue;
                        }

                        activateBlock(block);
                }
        }

        /*
                Mess around in active blocks
        */
        if(m_active_blocks_nodemetadata_interval.step(dtime, 1.0))
        {
                ScopeProfiler sp(g_profiler, "SEnv: mess in act. blocks avg /1s", SPT_AVG);
                
                float dtime = 1.0;

                for(core::map<v3s16, bool>::Iterator
                                i = m_active_blocks.m_list.getIterator();
                                i.atEnd()==false; i++)
                {
                        v3s16 p = i.getNode()->getKey();
                        
                        /*infostream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
                                        <<") being handled"<<std::endl;*/

                        MapBlock *block = m_map->getBlockNoCreateNoEx(p);
                        if(block==NULL)
                                continue;

                        // Reset block usage timer
                        block->resetUsageTimer();
                        
                        // Set current time as timestamp
                        block->setTimestampNoChangedFlag(m_game_time);
                        // If time has changed much from the one on disk,
                        // set block to be saved when it is unloaded
                        if(block->getTimestamp() > block->getDiskTimestamp() + 60)
                                block->raiseModified(MOD_STATE_WRITE_AT_UNLOAD,
                                                "Timestamp older than 60s (step)");

                        // Run node metadata
                        bool changed = block->m_node_metadata->step(dtime);
                        if(changed)
                        {
                                MapEditEvent event;
                                event.type = MEET_BLOCK_NODE_METADATA_CHANGED;
                                event.p = p;
                                m_map->dispatchEvent(&event);

                                block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                                "node metadata modified in step");
                        }
                }
        }
        
        const float abm_interval = 1.0;
        if(m_active_block_modifier_interval.step(dtime, abm_interval))
        {
                ScopeProfiler sp(g_profiler, "SEnv: modify in blocks avg /1s", SPT_AVG);
                TimeTaker timer("modify in active blocks");
                
                // Initialize handling of ActiveBlockModifiers
                ABMHandler abmhandler(m_abms, abm_interval, this, true);

                for(core::map<v3s16, bool>::Iterator
                                i = m_active_blocks.m_list.getIterator();
                                i.atEnd()==false; i++)
                {
                        v3s16 p = i.getNode()->getKey();
                        
                        /*infostream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
                                        <<") being handled"<<std::endl;*/

                        MapBlock *block = m_map->getBlockNoCreateNoEx(p);
                        if(block==NULL)
                                continue;
                        
                        // Set current time as timestamp
                        block->setTimestampNoChangedFlag(m_game_time);

                        /* Handle ActiveBlockModifiers */
                        abmhandler.apply(block);
                }

                u32 time_ms = timer.stop(true);
                u32 max_time_ms = 200;
                if(time_ms > max_time_ms){
                        infostream<<"WARNING: active block modifiers took "
                                        <<time_ms<<"ms (longer than "
                                        <<max_time_ms<<"ms)"<<std::endl;
                }
        }
        
        /*
                Step script environment (run global on_step())
        */
        scriptapi_environment_step(m_lua, dtime);

        /*
                Step active objects
        */
        {
                ScopeProfiler sp(g_profiler, "SEnv: step act. objs avg", SPT_AVG);
                //TimeTaker timer("Step active objects");

                g_profiler->avg("SEnv: num of objects", m_active_objects.size());
                
                // This helps the objects to send data at the same time
                bool send_recommended = false;
                m_send_recommended_timer += dtime;
                if(m_send_recommended_timer > getSendRecommendedInterval())
                {
                        m_send_recommended_timer -= getSendRecommendedInterval();
                        send_recommended = true;
                }

                for(core::map<u16, ServerActiveObject*>::Iterator
                                i = m_active_objects.getIterator();
                                i.atEnd()==false; i++)
                {
                        ServerActiveObject* obj = i.getNode()->getValue();
                        // Remove non-peaceful mobs on peaceful mode
                        if(g_settings->getBool("only_peaceful_mobs")){
                                if(!obj->isPeaceful())
                                        obj->m_removed = true;
                        }
                        // Don't step if is to be removed or stored statically
                        if(obj->m_removed || obj->m_pending_deactivation)
                                continue;
                        // Step object
                        obj->step(dtime, send_recommended);
                        // Read messages from object
                        while(obj->m_messages_out.size() > 0)
                        {
                                m_active_object_messages.push_back(
                                                obj->m_messages_out.pop_front());
                        }
                }
        }
        
        /*
                Manage active objects
        */
        if(m_object_management_interval.step(dtime, 0.5))
        {
                ScopeProfiler sp(g_profiler, "SEnv: remove removed objs avg /.5s", SPT_AVG);
                /*
                        Remove objects that satisfy (m_removed && m_known_by_count==0)
                */
                removeRemovedObjects();
        }
}

ServerActiveObject* ServerEnvironment::getActiveObject(u16 id)
{
        core::map<u16, ServerActiveObject*>::Node *n;
        n = m_active_objects.find(id);
        if(n == NULL)
                return NULL;
        return n->getValue();
}

bool isFreeServerActiveObjectId(u16 id,
                core::map<u16, ServerActiveObject*> &objects)
{
        if(id == 0)
                return false;
        
        for(core::map<u16, ServerActiveObject*>::Iterator
                        i = objects.getIterator();
                        i.atEnd()==false; i++)
        {
                if(i.getNode()->getKey() == id)
                        return false;
        }
        return true;
}

u16 getFreeServerActiveObjectId(
                core::map<u16, ServerActiveObject*> &objects)
{
        u16 new_id = 1;
        for(;;)
        {
                if(isFreeServerActiveObjectId(new_id, objects))
                        return new_id;
                
                if(new_id == 65535)
                        return 0;

                new_id++;
        }
}

u16 ServerEnvironment::addActiveObject(ServerActiveObject *object)
{
        assert(object);
        u16 id = addActiveObjectRaw(object, true);
        return id;
}

bool ServerEnvironment::addActiveObjectAsStatic(ServerActiveObject *obj)
{
        assert(obj);

        v3f objectpos = obj->getBasePosition(); 

        // The block in which the object resides in
        v3s16 blockpos_o = getNodeBlockPos(floatToInt(objectpos, BS));

        /*
                Update the static data
        */

        // Create new static object
        std::string staticdata = obj->getStaticData();
        StaticObject s_obj(obj->getType(), objectpos, staticdata);
        // Add to the block where the object is located in
        v3s16 blockpos = getNodeBlockPos(floatToInt(objectpos, BS));
        // Get or generate the block
        MapBlock *block = m_map->emergeBlock(blockpos);

        bool succeeded = false;

        if(block)
        {
                block->m_static_objects.insert(0, s_obj);
                block->raiseModified(MOD_STATE_WRITE_AT_UNLOAD,
                                "addActiveObjectAsStatic");
                succeeded = true;
        }
        else{
                infostream<<"ServerEnvironment::addActiveObjectAsStatic: "
                                <<"Could not find or generate "
                                <<"a block for storing static object"<<std::endl;
                succeeded = false;
        }

        delete obj;

        return succeeded;
}

/*
        Finds out what new objects have been added to
        inside a radius around a position
*/
void ServerEnvironment::getAddedActiveObjects(v3s16 pos, s16 radius,
                core::map<u16, bool> &current_objects,
                core::map<u16, bool> &added_objects)
{
        v3f pos_f = intToFloat(pos, BS);
        f32 radius_f = radius * BS;
        /*
                Go through the object list,
                - discard m_removed objects,
                - discard objects that are too far away,
                - discard objects that are found in current_objects.
                - add remaining objects to added_objects
        */
        for(core::map<u16, ServerActiveObject*>::Iterator
                        i = m_active_objects.getIterator();
                        i.atEnd()==false; i++)
        {
                u16 id = i.getNode()->getKey();
                // Get object
                ServerActiveObject *object = i.getNode()->getValue();
                if(object == NULL)
                        continue;
                // Discard if removed
                if(object->m_removed)
                        continue;
                // Discard if too far
                f32 distance_f = object->getBasePosition().getDistanceFrom(pos_f);
                if(distance_f > radius_f)
                        continue;
                // Discard if already on current_objects
                core::map<u16, bool>::Node *n;
                n = current_objects.find(id);
                if(n != NULL)
                        continue;
                // Add to added_objects
                added_objects.insert(id, false);
        }
}

/*
        Finds out what objects have been removed from
        inside a radius around a position
*/
void ServerEnvironment::getRemovedActiveObjects(v3s16 pos, s16 radius,
                core::map<u16, bool> &current_objects,
                core::map<u16, bool> &removed_objects)
{
        v3f pos_f = intToFloat(pos, BS);
        f32 radius_f = radius * BS;
        /*
                Go through current_objects; object is removed if:
                - object is not found in m_active_objects (this is actually an
                  error condition; objects should be set m_removed=true and removed
                  only after all clients have been informed about removal), or
                - object has m_removed=true, or
                - object is too far away
        */
        for(core::map<u16, bool>::Iterator
                        i = current_objects.getIterator();
                        i.atEnd()==false; i++)
        {
                u16 id = i.getNode()->getKey();
                ServerActiveObject *object = getActiveObject(id);
                if(object == NULL)
                {
                        infostream<<"ServerEnvironment::getRemovedActiveObjects():"
                                        <<" object in current_objects is NULL"<<std::endl;
                }
                else if(object->m_removed == false)
                {
                        f32 distance_f = object->getBasePosition().getDistanceFrom(pos_f);
                        /*infostream<<"removed == false"
                                        <<"distance_f = "<<distance_f
                                        <<", radius_f = "<<radius_f<<std::endl;*/
                        if(distance_f < radius_f)
                        {
                                // Not removed
                                continue;
                        }
                }
                removed_objects.insert(id, false);
        }
}

ActiveObjectMessage ServerEnvironment::getActiveObjectMessage()
{
        if(m_active_object_messages.size() == 0)
                return ActiveObjectMessage(0);
        
        return m_active_object_messages.pop_front();
}

/*
        ************ Private methods *************
*/

u16 ServerEnvironment::addActiveObjectRaw(ServerActiveObject *object,
                bool set_changed)
{
        assert(object);
        if(object->getId() == 0){
                u16 new_id = getFreeServerActiveObjectId(m_active_objects);
                if(new_id == 0)
                {
                        errorstream<<"ServerEnvironment::addActiveObjectRaw(): "
                                        <<"no free ids available"<<std::endl;
                        delete object;
                        return 0;
                }
                object->setId(new_id);
        }
        else{
                verbosestream<<"ServerEnvironment::addActiveObjectRaw(): "
                                <<"supplied with id "<<object->getId()<<std::endl;
        }
        if(isFreeServerActiveObjectId(object->getId(), m_active_objects) == false)
        {
                errorstream<<"ServerEnvironment::addActiveObjectRaw(): "
                                <<"id is not free ("<<object->getId()<<")"<<std::endl;
                delete object;
                return 0;
        }
        /*infostream<<"ServerEnvironment::addActiveObjectRaw(): "
                        <<"added (id="<<object->getId()<<")"<<std::endl;*/
                        
        m_active_objects.insert(object->getId(), object);
  
        verbosestream<<"ServerEnvironment::addActiveObjectRaw(): "
                        <<"Added id="<<object->getId()<<"; there are now "
                        <<m_active_objects.size()<<" active objects."
                        <<std::endl;
        
        // Add static object to active static list of the block
        v3f objectpos = object->getBasePosition();
        std::string staticdata = object->getStaticData();
        StaticObject s_obj(object->getType(), objectpos, staticdata);
        // Add to the block where the object is located in
        v3s16 blockpos = getNodeBlockPos(floatToInt(objectpos, BS));
        MapBlock *block = m_map->getBlockNoCreateNoEx(blockpos);
        if(block)
        {
                block->m_static_objects.m_active.insert(object->getId(), s_obj);
                object->m_static_exists = true;
                object->m_static_block = blockpos;

                if(set_changed)
                        block->raiseModified(MOD_STATE_WRITE_NEEDED, 
                                        "addActiveObjectRaw");
        }
        else{
                errorstream<<"ServerEnvironment::addActiveObjectRaw(): "
                                <<"could not find block for storing id="<<object->getId()
                                <<" statically"<<std::endl;
        }
        
        // Register reference in scripting api (must be done before post-init)
        scriptapi_add_object_reference(m_lua, object);
        // Post-initialize object
        object->addedToEnvironment();

        return object->getId();
}

/*
        Remove objects that satisfy (m_removed && m_known_by_count==0)
*/
void ServerEnvironment::removeRemovedObjects()
{
        core::list<u16> objects_to_remove;
        for(core::map<u16, ServerActiveObject*>::Iterator
                        i = m_active_objects.getIterator();
                        i.atEnd()==false; i++)
        {
                u16 id = i.getNode()->getKey();
                ServerActiveObject* obj = i.getNode()->getValue();
                // This shouldn't happen but check it
                if(obj == NULL)
                {
                        infostream<<"NULL object found in ServerEnvironment"
                                        <<" while finding removed objects. id="<<id<<std::endl;
                        // Id to be removed from m_active_objects
                        objects_to_remove.push_back(id);
                        continue;
                }

                /*
                        We will delete objects that are marked as removed or thatare
                        waiting for deletion after deactivation
                */
                if(obj->m_removed == false && obj->m_pending_deactivation == false)
                        continue;

                /*
                        Delete static data from block if is marked as removed
                */
                if(obj->m_static_exists && obj->m_removed)
                {
                        MapBlock *block = m_map->emergeBlock(obj->m_static_block);
                        if(block)
                        {
                                block->m_static_objects.remove(id);
                                block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                                "removeRemovedObjects");
                                obj->m_static_exists = false;
                        }
                }

                // If m_known_by_count > 0, don't actually remove.
                if(obj->m_known_by_count > 0)
                        continue;
                
                // Deregister in scripting api
                scriptapi_rm_object_reference(m_lua, obj);

                // Delete
                delete obj;
                // Id to be removed from m_active_objects
                objects_to_remove.push_back(id);
        }
        // Remove references from m_active_objects
        for(core::list<u16>::Iterator i = objects_to_remove.begin();
                        i != objects_to_remove.end(); i++)
        {
                m_active_objects.remove(*i);
        }
}

static void print_hexdump(std::ostream &o, const std::string &data)
{
        const int linelength = 16;
        for(int l=0; ; l++){
                int i0 = linelength * l;
                bool at_end = false;
                int thislinelength = linelength;
                if(i0 + thislinelength > (int)data.size()){
                        thislinelength = data.size() - i0;
                        at_end = true;
                }
                for(int di=0; di<linelength; di++){
                        int i = i0 + di;
                        char buf[4];
                        if(di<thislinelength)
                                snprintf(buf, 4, "%.2x ", data[i]);
                        else
                                snprintf(buf, 4, "   ");
                        o<<buf;
                }
                o<<" ";
                for(int di=0; di<thislinelength; di++){
                        int i = i0 + di;
                        if(data[i] >= 32)
                                o<<data[i];
                        else
                                o<<".";
                }
                o<<std::endl;
                if(at_end)
                        break;
        }
}

/*
        Convert stored objects from blocks near the players to active.
*/
void ServerEnvironment::activateObjects(MapBlock *block)
{
        if(block==NULL)
                return;
        // Ignore if no stored objects (to not set changed flag)
        if(block->m_static_objects.m_stored.size() == 0)
                return;
        verbosestream<<"ServerEnvironment::activateObjects(): "
                        <<"activating objects of block "<<PP(block->getPos())
                        <<" ("<<block->m_static_objects.m_stored.size()
                        <<" objects)"<<std::endl;
        bool large_amount = (block->m_static_objects.m_stored.size() > 49);
        if(large_amount){
                errorstream<<"suspiciously large amount of objects detected: "
                                <<block->m_static_objects.m_stored.size()<<" in "
                                <<PP(block->getPos())
                                <<"; removing all of them."<<std::endl;
                // Clear stored list
                block->m_static_objects.m_stored.clear();
                block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                "stored list cleared in activateObjects due to "
                                "large amount of objects");
                return;
        }
        // A list for objects that couldn't be converted to static for some
        // reason. They will be stored back.
        core::list<StaticObject> new_stored;
        // Loop through stored static objects
        for(core::list<StaticObject>::Iterator
                        i = block->m_static_objects.m_stored.begin();
                        i != block->m_static_objects.m_stored.end(); i++)
        {
                /*infostream<<"Server: Creating an active object from "
                                <<"static data"<<std::endl;*/
                StaticObject &s_obj = *i;
                // Create an active object from the data
                ServerActiveObject *obj = ServerActiveObject::create
                                (s_obj.type, this, 0, s_obj.pos, s_obj.data);
                // If couldn't create object, store static data back.
                if(obj==NULL)
                {
                        errorstream<<"ServerEnvironment::activateObjects(): "
                                        <<"failed to create active object from static object "
                                        <<"in block "<<PP(s_obj.pos/BS)
                                        <<" type="<<(int)s_obj.type<<" data:"<<std::endl;
                        print_hexdump(verbosestream, s_obj.data);
                        
                        new_stored.push_back(s_obj);
                        continue;
                }
                verbosestream<<"ServerEnvironment::activateObjects(): "
                                <<"activated static object pos="<<PP(s_obj.pos/BS)
                                <<" type="<<(int)s_obj.type<<std::endl;
                // This will also add the object to the active static list
                addActiveObjectRaw(obj, false);
        }
        // Clear stored list
        block->m_static_objects.m_stored.clear();
        // Add leftover failed stuff to stored list
        for(core::list<StaticObject>::Iterator
                        i = new_stored.begin();
                        i != new_stored.end(); i++)
        {
                StaticObject &s_obj = *i;
                block->m_static_objects.m_stored.push_back(s_obj);
        }
        /*
                Note: Block hasn't really been modified here.
                The objects have just been activated and moved from the stored
                static list to the active static list.
                As such, the block is essentially the same.
                Thus, do not call block->raiseModified(MOD_STATE_WRITE_NEEDED).
                Otherwise there would be a huge amount of unnecessary I/O.
        */
}

/*
        Convert objects that are not standing inside active blocks to static.

        If m_known_by_count != 0, active object is not deleted, but static
        data is still updated.

        If force_delete is set, active object is deleted nevertheless. It
        shall only be set so in the destructor of the environment.
*/
void ServerEnvironment::deactivateFarObjects(bool force_delete)
{
        core::list<u16> objects_to_remove;
        for(core::map<u16, ServerActiveObject*>::Iterator
                        i = m_active_objects.getIterator();
                        i.atEnd()==false; i++)
        {
                ServerActiveObject* obj = i.getNode()->getValue();

                // This shouldn't happen but check it
                if(obj == NULL)
                {
                        errorstream<<"NULL object found in ServerEnvironment"
                                        <<std::endl;
                        assert(0);
                        continue;
                }

                // If pending deactivation, let removeRemovedObjects() do it
                if(obj->m_pending_deactivation)
                        continue;

                u16 id = i.getNode()->getKey();         
                v3f objectpos = obj->getBasePosition(); 

                // The block in which the object resides in
                v3s16 blockpos_o = getNodeBlockPos(floatToInt(objectpos, BS));

                // If block is active, don't remove
                if(m_active_blocks.contains(blockpos_o))
                        continue;

                verbosestream<<"ServerEnvironment::deactivateFarObjects(): "
                                <<"deactivating object id="<<id<<" on inactive block "
                                <<PP(blockpos_o)<<std::endl;

                // If known by some client, don't immediately delete.
                bool pending_delete = (obj->m_known_by_count > 0 && !force_delete);

                /*
                        Update the static data
                */

                // Create new static object
                std::string staticdata_new = obj->getStaticData();
                StaticObject s_obj(obj->getType(), objectpos, staticdata_new);
                
                bool stays_in_same_block = false;
                bool data_changed = true;

                if(obj->m_static_exists){
                        if(obj->m_static_block == blockpos_o)
                                stays_in_same_block = true;

                        MapBlock *block = m_map->emergeBlock(obj->m_static_block, false);
                        
                        core::map<u16, StaticObject>::Node *n =
                                        block->m_static_objects.m_active.find(id);
                        if(n){
                                StaticObject static_old = n->getValue();

                                float save_movem = obj->getMinimumSavedMovement();

                                if(static_old.data == staticdata_new &&
                                                (static_old.pos - objectpos).getLength() < save_movem)
                                        data_changed = false;
                        } else {
                                errorstream<<"ServerEnvironment::deactivateFarObjects(): "
                                                <<"id="<<id<<" m_static_exists=true but "
                                                <<"static data doesn't actually exist in "
                                                <<PP(obj->m_static_block)<<std::endl;
                        }
                }

                bool shall_be_written = (!stays_in_same_block || data_changed);
                
                // Delete old static object
                if(obj->m_static_exists)
                {
                        MapBlock *block = m_map->emergeBlock(obj->m_static_block, false);
                        if(block)
                        {
                                block->m_static_objects.remove(id);
                                obj->m_static_exists = false;
                                // Only mark block as modified if data changed considerably
                                if(shall_be_written)
                                        block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                                        "deactivateFarObjects: Static data "
                                                        "changed considerably");
                        }
                }

                // Add to the block where the object is located in
                v3s16 blockpos = getNodeBlockPos(floatToInt(objectpos, BS));
                // Get or generate the block
                MapBlock *block = m_map->emergeBlock(blockpos);

                if(block)
                {
                        if(block->m_static_objects.m_stored.size() >= 49){
                                errorstream<<"ServerEnv: Trying to store id="<<obj->getId()
                                                <<" statically but block "<<PP(blockpos)
                                                <<" already contains "
                                                <<block->m_static_objects.m_stored.size()
                                                <<" (over 49) objects."
                                                <<" Forcing delete."<<std::endl;
                                force_delete = true;
                        } else {
                                u16 new_id = pending_delete ? id : 0;
                                block->m_static_objects.insert(new_id, s_obj);
                                
                                // Only mark block as modified if data changed considerably
                                if(shall_be_written)
                                        block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                                        "deactivateFarObjects: Static data "
                                                        "changed considerably");
                                
                                obj->m_static_exists = true;
                                obj->m_static_block = block->getPos();
                        }
                }
                else{
                        errorstream<<"ServerEnv: Could not find or generate "
                                        <<"a block for storing id="<<obj->getId()
                                        <<" statically"<<std::endl;
                        continue;
                }

                /*
                        If known by some client, set pending deactivation.
                        Otherwise delete it immediately.
                */

                if(pending_delete)
                {
                        verbosestream<<"ServerEnvironment::deactivateFarObjects(): "
                                        <<"object id="<<id<<" is known by clients"
                                        <<"; not deleting yet"<<std::endl;

                        obj->m_pending_deactivation = true;
                        continue;
                }
                
                verbosestream<<"ServerEnvironment::deactivateFarObjects(): "
                                <<"object id="<<id<<" is not known by clients"
                                <<"; deleting"<<std::endl;

                // Deregister in scripting api
                scriptapi_rm_object_reference(m_lua, obj);

                // Delete active object
                delete obj;
                // Id to be removed from m_active_objects
                objects_to_remove.push_back(id);
        }

        // Remove references from m_active_objects
        for(core::list<u16>::Iterator i = objects_to_remove.begin();
                        i != objects_to_remove.end(); i++)
        {
                m_active_objects.remove(*i);
        }
}


#ifndef SERVER

/*
        ClientEnvironment
*/

ClientEnvironment::ClientEnvironment(ClientMap *map, scene::ISceneManager *smgr,
                ITextureSource *texturesource, IGameDef *gamedef):
        m_map(map),
        m_smgr(smgr),
        m_texturesource(texturesource),
        m_gamedef(gamedef)
{
        assert(m_map);
        assert(m_smgr);
}

ClientEnvironment::~ClientEnvironment()
{
        // delete active objects
        for(core::map<u16, ClientActiveObject*>::Iterator
                        i = m_active_objects.getIterator();
                        i.atEnd()==false; i++)
        {
                delete i.getNode()->getValue();
        }

        // Drop/delete map
        m_map->drop();
}

void ClientEnvironment::addPlayer(Player *player)
{
        DSTACK(__FUNCTION_NAME);
        /*
                It is a failure if player is local and there already is a local
                player
        */
        assert(!(player->isLocal() == true && getLocalPlayer() != NULL));

        Environment::addPlayer(player);
}

LocalPlayer * ClientEnvironment::getLocalPlayer()
{
        for(core::list<Player*>::Iterator i = m_players.begin();
                        i != m_players.end(); i++)
        {
                Player *player = *i;
                if(player->isLocal())
                        return (LocalPlayer*)player;
        }
        return NULL;
}

void ClientEnvironment::step(float dtime)
{
        DSTACK(__FUNCTION_NAME);

        // Get some settings
        bool free_move = g_settings->getBool("free_move");
        bool footprints = g_settings->getBool("footprints");

        // Get local player
        LocalPlayer *lplayer = getLocalPlayer();
        assert(lplayer);
        // collision info queue
        core::list<CollisionInfo> player_collisions;
        
        /*
                Get the speed the player is going
        */
        bool is_climbing = lplayer->is_climbing;
        
        f32 player_speed = lplayer->getSpeed().getLength();
        
        /*
                Maximum position increment
        */
        //f32 position_max_increment = 0.05*BS;
        f32 position_max_increment = 0.1*BS;

        // Maximum time increment (for collision detection etc)
        // time = distance / speed
        f32 dtime_max_increment = 1;
        if(player_speed > 0.001)
                dtime_max_increment = position_max_increment / player_speed;
        
        // Maximum time increment is 10ms or lower
        if(dtime_max_increment > 0.01)
                dtime_max_increment = 0.01;
        
        // Don't allow overly huge dtime
        if(dtime > 0.5)
                dtime = 0.5;
        
        f32 dtime_downcount = dtime;

        /*
                Stuff that has a maximum time increment
        */

        u32 loopcount = 0;
        do
        {
                loopcount++;

                f32 dtime_part;
                if(dtime_downcount > dtime_max_increment)
                {
                        dtime_part = dtime_max_increment;
                        dtime_downcount -= dtime_part;
                }
                else
                {
                        dtime_part = dtime_downcount;
                        /*
                                Setting this to 0 (no -=dtime_part) disables an infinite loop
                                when dtime_part is so small that dtime_downcount -= dtime_part
                                does nothing
                        */
                        dtime_downcount = 0;
                }
                
                /*
                        Handle local player
                */
                
                {
                        v3f lplayerpos = lplayer->getPosition();
                        
                        // Apply physics
                        if(free_move == false && is_climbing == false)
                        {
                                // Gravity
                                v3f speed = lplayer->getSpeed();
                                if(lplayer->swimming_up == false)
                                        speed.Y -= 9.81 * BS * dtime_part * 2;

                                // Water resistance
                                if(lplayer->in_water_stable || lplayer->in_water)
                                {
                                        f32 max_down = 2.0*BS;
                                        if(speed.Y < -max_down) speed.Y = -max_down;

                                        f32 max = 2.5*BS;
                                        if(speed.getLength() > max)
                                        {
                                                speed = speed / speed.getLength() * max;
                                        }
                                }

                                lplayer->setSpeed(speed);
                        }

                        /*
                                Move the lplayer.
                                This also does collision detection.
                        */
                        lplayer->move(dtime_part, *m_map, position_max_increment,
                                        &player_collisions);
                }
        }
        while(dtime_downcount > 0.001);
                
        //std::cout<<"Looped "<<loopcount<<" times."<<std::endl;
        
        for(core::list<CollisionInfo>::Iterator
                        i = player_collisions.begin();
                        i != player_collisions.end(); i++)
        {
                CollisionInfo &info = *i;
                if(info.t == COLLISION_FALL)
                {
                        //f32 tolerance = BS*10; // 2 without damage
                        f32 tolerance = BS*12; // 3 without damage
                        f32 factor = 1;
                        if(info.speed > tolerance)
                        {
                                f32 damage_f = (info.speed - tolerance)/BS*factor;
                                u16 damage = (u16)(damage_f+0.5);
                                if(lplayer->hp > damage)
                                        lplayer->hp -= damage;
                                else
                                        lplayer->hp = 0;

                                ClientEnvEvent event;
                                event.type = CEE_PLAYER_DAMAGE;
                                event.player_damage.amount = damage;
                                m_client_event_queue.push_back(event);
                        }
                }
        }
        
        /*
                A quick draft of lava damage
        */
        if(m_lava_hurt_interval.step(dtime, 1.0))
        {
                v3f pf = lplayer->getPosition();
                
                // Feet, middle and head
                v3s16 p1 = floatToInt(pf + v3f(0, BS*0.1, 0), BS);
                MapNode n1 = m_map->getNodeNoEx(p1);
                v3s16 p2 = floatToInt(pf + v3f(0, BS*0.8, 0), BS);
                MapNode n2 = m_map->getNodeNoEx(p2);
                v3s16 p3 = floatToInt(pf + v3f(0, BS*1.6, 0), BS);
                MapNode n3 = m_map->getNodeNoEx(p2);

                u32 damage_per_second = 0;
                damage_per_second = MYMAX(damage_per_second,
                                m_gamedef->ndef()->get(n1).damage_per_second);
                damage_per_second = MYMAX(damage_per_second,
                                m_gamedef->ndef()->get(n2).damage_per_second);
                damage_per_second = MYMAX(damage_per_second,
                                m_gamedef->ndef()->get(n3).damage_per_second);
                
                if(damage_per_second != 0)
                {
                        ClientEnvEvent event;
                        event.type = CEE_PLAYER_DAMAGE;
                        event.player_damage.amount = damage_per_second;
                        m_client_event_queue.push_back(event);
                }
        }
        
        /*
                Stuff that can be done in an arbitarily large dtime
        */
        for(core::list<Player*>::Iterator i = m_players.begin();
                        i != m_players.end(); i++)
        {
                Player *player = *i;
                v3f playerpos = player->getPosition();
                
                /*
                        Handle non-local players
                */
                if(player->isLocal() == false)
                {
                        // Move
                        player->move(dtime, *m_map, 100*BS);

                }
                
                // Update lighting on all players on client
                u8 light = LIGHT_MAX;
                try{
                        // Get node at head
                        v3s16 p = player->getLightPosition();
                        MapNode n = m_map->getNode(p);
                        light = n.getLightBlend(getDayNightRatio(), m_gamedef->ndef());
                }
                catch(InvalidPositionException &e) {}
                player->updateLight(light);

                /*
                        Add footsteps to grass
                */
                if(footprints)
                {
                        // Get node that is at BS/4 under player
                        v3s16 bottompos = floatToInt(playerpos + v3f(0,-BS/4,0), BS);
                        try{
                                MapNode n = m_map->getNode(bottompos);
                                if(n.getContent() == LEGN(m_gamedef->ndef(), "CONTENT_GRASS"))
                                {
                                        n.setContent(LEGN(m_gamedef->ndef(), "CONTENT_GRASS_FOOTSTEPS"));
                                        m_map->setNode(bottompos, n);
                                        // Update mesh on client
                                        if(m_map->mapType() == MAPTYPE_CLIENT)
                                        {
                                                v3s16 p_blocks = getNodeBlockPos(bottompos);
                                                MapBlock *b = m_map->getBlockNoCreate(p_blocks);
                                                //b->updateMesh(getDayNightRatio());
                                                b->setMeshExpired(true);
                                        }
                                }
                        }
                        catch(InvalidPositionException &e)
                        {
                        }
                }
        }
        
        /*
                Step active objects and update lighting of them
        */
        
        for(core::map<u16, ClientActiveObject*>::Iterator
                        i = m_active_objects.getIterator();
                        i.atEnd()==false; i++)
        {
                ClientActiveObject* obj = i.getNode()->getValue();
                // Step object
                obj->step(dtime, this);

                if(m_active_object_light_update_interval.step(dtime, 0.21))
                {
                        // Update lighting
                        //u8 light = LIGHT_MAX;
                        u8 light = 0;
                        try{
                                // Get node at head
                                v3s16 p = obj->getLightPosition();
                                MapNode n = m_map->getNode(p);
                                light = n.getLightBlend(getDayNightRatio(), m_gamedef->ndef());
                        }
                        catch(InvalidPositionException &e) {}
                        obj->updateLight(light);
                }
        }
}

void ClientEnvironment::updateMeshes(v3s16 blockpos)
{
        m_map->updateMeshes(blockpos, getDayNightRatio());
}

void ClientEnvironment::expireMeshes(bool only_daynight_diffed)
{
        m_map->expireMeshes(only_daynight_diffed);
}

ClientActiveObject* ClientEnvironment::getActiveObject(u16 id)
{
        core::map<u16, ClientActiveObject*>::Node *n;
        n = m_active_objects.find(id);
        if(n == NULL)
                return NULL;
        return n->getValue();
}

bool isFreeClientActiveObjectId(u16 id,
                core::map<u16, ClientActiveObject*> &objects)
{
        if(id == 0)
                return false;
        
        for(core::map<u16, ClientActiveObject*>::Iterator
                        i = objects.getIterator();
                        i.atEnd()==false; i++)
        {
                if(i.getNode()->getKey() == id)
                        return false;
        }
        return true;
}

u16 getFreeClientActiveObjectId(
                core::map<u16, ClientActiveObject*> &objects)
{
        u16 new_id = 1;
        for(;;)
        {
                if(isFreeClientActiveObjectId(new_id, objects))
                        return new_id;
                
                if(new_id == 65535)
                        return 0;

                new_id++;
        }
}

u16 ClientEnvironment::addActiveObject(ClientActiveObject *object)
{
        assert(object);
        if(object->getId() == 0)
        {
                u16 new_id = getFreeClientActiveObjectId(m_active_objects);
                if(new_id == 0)
                {
                        infostream<<"ClientEnvironment::addActiveObject(): "
                                        <<"no free ids available"<<std::endl;
                        delete object;
                        return 0;
                }
                object->setId(new_id);
        }
        if(isFreeClientActiveObjectId(object->getId(), m_active_objects) == false)
        {
                infostream<<"ClientEnvironment::addActiveObject(): "
                                <<"id is not free ("<<object->getId()<<")"<<std::endl;
                delete object;
                return 0;
        }
        infostream<<"ClientEnvironment::addActiveObject(): "
                        <<"added (id="<<object->getId()<<")"<<std::endl;
        m_active_objects.insert(object->getId(), object);
        object->addToScene(m_smgr, m_texturesource);
        { // Update lighting immediately
                u8 light = 0;
                try{
                        // Get node at head
                        v3s16 p = object->getLightPosition();
                        MapNode n = m_map->getNode(p);
                        light = n.getLightBlend(getDayNightRatio(), m_gamedef->ndef());
                }
                catch(InvalidPositionException &e) {}
                object->updateLight(light);
        }
        return object->getId();
}

void ClientEnvironment::addActiveObject(u16 id, u8 type,
                const std::string &init_data)
{
        ClientActiveObject* obj = ClientActiveObject::create(type, m_gamedef);
        if(obj == NULL)
        {
                infostream<<"ClientEnvironment::addActiveObject(): "
                                <<"id="<<id<<" type="<<type<<": Couldn't create object"
                                <<std::endl;
                return;
        }
        
        obj->setId(id);

        obj->initialize(init_data);
        
        addActiveObject(obj);
}

void ClientEnvironment::removeActiveObject(u16 id)
{
        infostream<<"ClientEnvironment::removeActiveObject(): "
                        <<"id="<<id<<std::endl;
        ClientActiveObject* obj = getActiveObject(id);
        if(obj == NULL)
        {
                infostream<<"ClientEnvironment::removeActiveObject(): "
                                <<"id="<<id<<" not found"<<std::endl;
                return;
        }
        obj->removeFromScene();
        delete obj;
        m_active_objects.remove(id);
}

void ClientEnvironment::processActiveObjectMessage(u16 id,
                const std::string &data)
{
        ClientActiveObject* obj = getActiveObject(id);
        if(obj == NULL)
        {
                infostream<<"ClientEnvironment::processActiveObjectMessage():"
                                <<" got message for id="<<id<<", which doesn't exist."
                                <<std::endl;
                return;
        }
        obj->processMessage(data);
}

/*
        Callbacks for activeobjects
*/

void ClientEnvironment::damageLocalPlayer(u8 damage)
{
        LocalPlayer *lplayer = getLocalPlayer();
        assert(lplayer);

        if(lplayer->hp > damage)
                lplayer->hp -= damage;
        else
                lplayer->hp = 0;

        ClientEnvEvent event;
        event.type = CEE_PLAYER_DAMAGE;
        event.player_damage.amount = damage;
        m_client_event_queue.push_back(event);
}

/*
        Client likes to call these
*/
        
void ClientEnvironment::getActiveObjects(v3f origin, f32 max_d,
                core::array<DistanceSortedActiveObject> &dest)
{
        for(core::map<u16, ClientActiveObject*>::Iterator
                        i = m_active_objects.getIterator();
                        i.atEnd()==false; i++)
        {
                ClientActiveObject* obj = i.getNode()->getValue();

                f32 d = (obj->getPosition() - origin).getLength();

                if(d > max_d)
                        continue;

                DistanceSortedActiveObject dso(obj, d);

                dest.push_back(dso);
        }
}

ClientEnvEvent ClientEnvironment::getClientEvent()
{
        if(m_client_event_queue.size() == 0)
        {
                ClientEnvEvent event;
                event.type = CEE_NONE;
                return event;
        }
        return m_client_event_queue.pop_front();
}

#endif // #ifndef SERVER