Core/Maps: Implemented loading swapped maps

13 files changed, 184 insertions, 75 deletions

diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index 68d5024e959..ffe6349e161 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -2132,7 +2132,7 @@ GameObject* Player::GetGameObjectIfCanInteractWith(ObjectGuid const& guid, Gameo
 bool Player::IsUnderWater() const
 {
     return IsInWater() &&
-        GetPositionZ() < (GetBaseMap()->GetWaterLevel(GetPositionX(), GetPositionY())-2);
+        GetPositionZ() < (GetBaseMap()->GetWaterLevel(GetPhaseShift(), GetPositionX(), GetPositionY()) - 2);
 }
 
 void Player::SetInWater(bool apply)
@@ -6946,7 +6946,7 @@ uint32 Player::GetZoneIdFromDB(ObjectGuid guid)
         if (!sMapStore.LookupEntry(map))
             return 0;
 
-        zone = sMapMgr->GetZoneId(PhaseShift(), map, posx, posy, posz);
+        zone = sMapMgr->GetZoneId(PhasingHandler::GetEmptyPhaseShift(), map, posx, posy, posz);
 
         if (zone > 0)
         {
diff --git a/src/server/game/Globals/ObjectMgr.cpp b/src/server/game/Globals/ObjectMgr.cpp
index 737f1952348..dc8604fa2e8 100644
--- a/src/server/game/Globals/ObjectMgr.cpp
+++ b/src/server/game/Globals/ObjectMgr.cpp
@@ -6252,7 +6252,7 @@ WorldSafeLocsEntry const* ObjectMgr::GetClosestGraveYard(WorldLocation const& lo
     uint32 MapId = location.GetMapId();
 
     // search for zone associated closest graveyard
-    uint32 zoneId = sMapMgr->GetZoneId(PhaseShift(), MapId, x, y, z);
+    uint32 zoneId = sMapMgr->GetZoneId(PhasingHandler::GetEmptyPhaseShift(), MapId, x, y, z);
 
     if (!zoneId)
     {
diff --git a/src/server/game/Maps/Map.cpp b/src/server/game/Maps/Map.cpp
index 6ece7791b6e..c3e1aa744d3 100644
--- a/src/server/game/Maps/Map.cpp
+++ b/src/server/game/Maps/Map.cpp
@@ -85,6 +85,9 @@ Map::~Map()
     if (!m_scriptSchedule.empty())
         sMapMgr->DecreaseScheduledScriptCount(m_scriptSchedule.size());
 
+    if (m_parentMap == this)
+        delete m_childTerrainMaps;
+
     MMAP::MMapFactory::createOrGetMMapManager()->unloadMapInstance(GetId(), i_InstanceId);
 }
 
@@ -171,42 +174,65 @@ void Map::LoadVMap(int gx, int gy)
 
 void Map::LoadMap(int gx, int gy, bool reload)
 {
-    if (i_InstanceId != 0)
+    LoadMapImpl(this, gx, gy, reload);
+    for (Map* childBaseMap : *m_childTerrainMaps)
+        LoadMapImpl(childBaseMap, gx, gy, reload);
+}
+
+void Map::LoadMapImpl(Map* map, int gx, int gy, bool reload)
+{
+    if (map->i_InstanceId != 0)
     {
-        if (GridMaps[gx][gy])
+        if (map->GridMaps[gx][gy])
             return;
 
         // load grid map for base map
-        if (!m_parentMap->GridMaps[gx][gy])
-            m_parentMap->EnsureGridCreated(GridCoord((MAX_NUMBER_OF_GRIDS - 1) - gx, (MAX_NUMBER_OF_GRIDS - 1) - gy));
+        if (!map->m_parentMap->GridMaps[gx][gy])
+            map->m_parentMap->EnsureGridCreated(GridCoord((MAX_NUMBER_OF_GRIDS - 1) - gx, (MAX_NUMBER_OF_GRIDS - 1) - gy));
 
-        ((MapInstanced*)(m_parentMap))->AddGridMapReference(GridCoord(gx, gy));
-        GridMaps[gx][gy] = m_parentMap->GridMaps[gx][gy];
+        map->m_parentMap->ToMapInstanced()->AddGridMapReference(GridCoord(gx, gy));
+        map->GridMaps[gx][gy] = map->m_parentMap->GridMaps[gx][gy];
         return;
     }
 
-    if (GridMaps[gx][gy] && !reload)
+    if (map->GridMaps[gx][gy] && !reload)
         return;
 
     //map already load, delete it before reloading (Is it necessary? Do we really need the ability the reload maps during runtime?)
-    if (GridMaps[gx][gy])
+    if (map->GridMaps[gx][gy])
     {
-        TC_LOG_DEBUG("maps", "Unloading previously loaded map %u before reloading.", GetId());
-        sScriptMgr->OnUnloadGridMap(this, GridMaps[gx][gy], gx, gy);
+        TC_LOG_DEBUG("maps", "Unloading previously loaded map %u before reloading.", map->GetId());
+        sScriptMgr->OnUnloadGridMap(map, map->GridMaps[gx][gy], gx, gy);
 
-        delete (GridMaps[gx][gy]);
-        GridMaps[gx][gy]=NULL;
+        delete map->GridMaps[gx][gy];
+        map->GridMaps[gx][gy] = nullptr;
     }
 
     // map file name
-    std::string fileName = Trinity::StringFormat("%smaps/%04u_%02u_%02u.map", sWorld->GetDataPath().c_str(), GetId(), gx, gy);
+    std::string fileName = Trinity::StringFormat("%smaps/%04u_%02u_%02u.map", sWorld->GetDataPath().c_str(), map->GetId(), gx, gy);
     TC_LOG_DEBUG("maps", "Loading map %s", fileName.c_str());
     // loading data
-    GridMaps[gx][gy] = new GridMap();
-    if (!GridMaps[gx][gy]->loadData(fileName.c_str()))
+    map->GridMaps[gx][gy] = new GridMap();
+    if (!map->GridMaps[gx][gy]->loadData(fileName.c_str()))
         TC_LOG_ERROR("maps", "Error loading map file: %s", fileName.c_str());
 
-    sScriptMgr->OnLoadGridMap(this, GridMaps[gx][gy], gx, gy);
+    sScriptMgr->OnLoadGridMap(map, map->GridMaps[gx][gy], gx, gy);
+}
+
+void Map::UnloadMap(Map* map, int gx, int gy)
+{
+    if (map->i_InstanceId == 0)
+    {
+        if (map->GridMaps[gx][gy])
+        {
+            map->GridMaps[gx][gy]->unloadData();
+            delete map->GridMaps[gx][gy];
+        }
+    }
+    else
+        static_cast<MapInstanced*>(map->m_parentMap)->RemoveGridMapReference(GridCoord(gx, gy));
+
+    map->GridMaps[gx][gy] = nullptr;
 }
 
 void Map::LoadMapAndVMap(int gx, int gy)
@@ -229,10 +255,10 @@ void Map::LoadAllCells()
 
 void Map::InitStateMachine()
 {
-    si_GridStates[GRID_STATE_INVALID] = new InvalidState;
-    si_GridStates[GRID_STATE_ACTIVE] = new ActiveState;
-    si_GridStates[GRID_STATE_IDLE] = new IdleState;
-    si_GridStates[GRID_STATE_REMOVAL] = new RemovalState;
+    si_GridStates[GRID_STATE_INVALID] = new InvalidState();
+    si_GridStates[GRID_STATE_ACTIVE] = new ActiveState();
+    si_GridStates[GRID_STATE_IDLE] = new IdleState();
+    si_GridStates[GRID_STATE_REMOVAL] = new RemovalState();
 }
 
 void Map::DeleteStateMachine()
@@ -252,14 +278,24 @@ m_activeNonPlayersIter(m_activeNonPlayers.end()), _transportsUpdateIter(_transpo
 i_gridExpiry(expiry),
 i_scriptLock(false), _defaultLight(DB2Manager::GetDefaultMapLight(id))
 {
-    m_parentMap = (_parent ? _parent : this);
-    for (unsigned int idx=0; idx < MAX_NUMBER_OF_GRIDS; ++idx)
+    if (_parent)
     {
-        for (unsigned int j=0; j < MAX_NUMBER_OF_GRIDS; ++j)
+        m_parentMap = _parent;
+        m_childTerrainMaps = m_parentMap->m_childTerrainMaps;
+    }
+    else
+    {
+        m_parentMap = this;
+        m_childTerrainMaps = new std::vector<Map*>();
+    }
+
+    for (uint32 x = 0; x < MAX_NUMBER_OF_GRIDS; ++x)
+    {
+        for (uint32 y = 0; y < MAX_NUMBER_OF_GRIDS; ++y)
         {
             //z code
-            GridMaps[idx][j] =NULL;
-            setNGrid(NULL, idx, j);
+            GridMaps[x][y] = nullptr;
+            setNGrid(nullptr, x, y);
         }
     }
 
@@ -1782,20 +1818,16 @@ bool Map::UnloadGrid(NGridType& ngrid, bool unloadAll)
     // delete grid map, but don't delete if it is from parent map (and thus only reference)
     //+++if (GridMaps[gx][gy]) don't check for GridMaps[gx][gy], we might have to unload vmaps
     {
+        for (Map* childBaseMap : *m_childTerrainMaps)
+            UnloadMap(childBaseMap, gx, gy);
+
+        UnloadMap(this, gx, gy);
+
         if (i_InstanceId == 0)
         {
-            if (GridMaps[gx][gy])
-            {
-                GridMaps[gx][gy]->unloadData();
-                delete GridMaps[gx][gy];
-            }
             VMAP::VMapFactory::createOrGetVMapManager()->unloadMap(GetId(), gx, gy);
             MMAP::MMapFactory::createOrGetMMapManager()->unloadMap(GetId(), gx, gy);
         }
-        else
-            ((MapInstanced*)m_parentMap)->RemoveGridMapReference(GridCoord(gx, gy));
-
-        GridMaps[gx][gy] = NULL;
     }
     TC_LOG_DEBUG("maps", "Unloading grid[%u, %u] for map %u finished", x, y, GetId());
     return true;
@@ -1881,6 +1913,7 @@ GridMap::GridMap()
     _liquidEntry = nullptr;
     _liquidFlags = nullptr;
     _liquidMap  = nullptr;
+    _fileExists = false;
 }
 
 GridMap::~GridMap()
@@ -1899,6 +1932,7 @@ bool GridMap::loadData(const char* filename)
     if (!in)
         return true;
 
+    _fileExists = true;
     if (fread(&header, sizeof(header), 1, in) != 1)
     {
         fclose(in);
@@ -1957,6 +1991,7 @@ void GridMap::unloadData()
     _liquidFlags = nullptr;
     _liquidMap  = nullptr;
     _gridGetHeight = &GridMap::getHeightFromFlat;
+    _fileExists = false;
 }
 
 bool GridMap::loadAreaData(FILE* in, uint32 offset, uint32 /*size*/)
@@ -2500,6 +2535,26 @@ inline GridMap* Map::GetGrid(float x, float y)
     return GridMaps[gx][gy];
 }
 
+GridMap* Map::GetGrid(uint32 mapId, float x, float y)
+{
+    if (GetId() == mapId)
+        return GetGrid(x, y);
+
+    // half opt method
+    int gx = (int)(CENTER_GRID_ID - x / SIZE_OF_GRIDS);                   //grid x
+    int gy = (int)(CENTER_GRID_ID - y / SIZE_OF_GRIDS);                   //grid y
+
+    // ensure GridMap is loaded
+    EnsureGridCreated(GridCoord((MAX_NUMBER_OF_GRIDS - 1) - gx, (MAX_NUMBER_OF_GRIDS - 1) - gy));
+
+    GridMap* grid = GridMaps[gx][gy];
+    auto childMapItr = std::find_if(m_childTerrainMaps->begin(), m_childTerrainMaps->end(), [mapId](Map* childTerrainMap) {return childTerrainMap->GetId() == mapId; });
+    if (childMapItr != m_childTerrainMaps->end() && (*childMapItr)->GridMaps[gx][gy]->fileExists())
+        grid = (*childMapItr)->GridMaps[gx][gy];
+
+    return grid;
+}
+
 float Map::GetWaterOrGroundLevel(PhaseShift const& phaseShift, float x, float y, float z, float* ground /*= nullptr*/, bool /*swim = false*/) const
 {
     if (const_cast<Map*>(this)->GetGrid(x, y))
@@ -2522,7 +2577,8 @@ float Map::GetStaticHeight(PhaseShift const& phaseShift, float x, float y, float
 {
     // find raw .map surface under Z coordinates
     float mapHeight = VMAP_INVALID_HEIGHT_VALUE;
-    if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(x, y))
+    uint32 terrainMapId = phaseShift.GetTerrainMapId(GetId(), x, y);
+    if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(terrainMapId, x, y))
     {
         float gridHeight = gmap->getHeight(x, y);
         // look from a bit higher pos to find the floor, ignore under surface case
@@ -2535,7 +2591,7 @@ float Map::GetStaticHeight(PhaseShift const& phaseShift, float x, float y, float
     {
         VMAP::IVMapManager* vmgr = VMAP::VMapFactory::createOrGetVMapManager();
         if (vmgr->isHeightCalcEnabled())
-            vmapHeight = vmgr->getHeight(phaseShift.GetTerrainMapId(GetId(), x, y), x, y, z + 2.0f, maxSearchDist);   // look from a bit higher pos to find the floor
+            vmapHeight = vmgr->getHeight(terrainMapId, x, y, z + 2.0f, maxSearchDist);   // look from a bit higher pos to find the floor
     }
 
     // mapHeight set for any above raw ground Z or <= INVALID_HEIGHT
@@ -2614,11 +2670,12 @@ bool Map::IsOutdoors(PhaseShift const& phaseShift, float x, float y, float z) co
 bool Map::GetAreaInfo(PhaseShift const& phaseShift, float x, float y, float z, uint32 &flags, int32 &adtId, int32 &rootId, int32 &groupId) const
 {
     float vmap_z = z;
+    uint32 terrainMapId = phaseShift.GetTerrainMapId(GetId(), x, y);
     VMAP::IVMapManager* vmgr = VMAP::VMapFactory::createOrGetVMapManager();
-    if (vmgr->getAreaInfo(phaseShift.GetTerrainMapId(GetId(), x, y), x, y, vmap_z, flags, adtId, rootId, groupId))
+    if (vmgr->getAreaInfo(terrainMapId, x, y, vmap_z, flags, adtId, rootId, groupId))
     {
         // check if there's terrain between player height and object height
-        if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(x, y))
+        if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(terrainMapId, x, y))
         {
             float _mapheight = gmap->getHeight(x, y);
             // z + 2.0f condition taken from GetHeight(), not sure if it's such a great choice...
@@ -2652,7 +2709,7 @@ uint32 Map::GetAreaId(PhaseShift const& phaseShift, float x, float y, float z, b
 
     if (!areaId)
     {
-        if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(x, y))
+        if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(phaseShift.GetTerrainMapId(GetId(), x, y), x, y))
             areaId = gmap->getArea(x, y);
 
         // this used while not all *.map files generated (instances)
@@ -2693,9 +2750,9 @@ void Map::GetZoneAndAreaId(PhaseShift const& phaseShift, uint32& zoneid, uint32&
             zoneid = area->ParentAreaID;
 }
 
-uint8 Map::GetTerrainType(float x, float y) const
+uint8 Map::GetTerrainType(PhaseShift const& phaseShift, float x, float y) const
 {
-    if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(x, y))
+    if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(phaseShift.GetTerrainMapId(GetId(), x, y), x, y))
         return gmap->getTerrainType(x, y);
     else
         return 0;
@@ -2708,7 +2765,8 @@ ZLiquidStatus Map::getLiquidStatus(PhaseShift const& phaseShift, float x, float
     float liquid_level = INVALID_HEIGHT;
     float ground_level = INVALID_HEIGHT;
     uint32 liquid_type = 0;
-    if (vmgr->GetLiquidLevel(phaseShift.GetTerrainMapId(GetId(), x, y), x, y, z, ReqLiquidType, liquid_level, ground_level, liquid_type))
+    uint32 terrainMapId = phaseShift.GetTerrainMapId(GetId(), x, y);
+    if (vmgr->GetLiquidLevel(terrainMapId, x, y, z, ReqLiquidType, liquid_level, ground_level, liquid_type))
     {
         TC_LOG_DEBUG("maps", "getLiquidStatus(): vmap liquid level: %f ground: %f type: %u", liquid_level, ground_level, liquid_type);
         // Check water level and ground level
@@ -2765,7 +2823,7 @@ ZLiquidStatus Map::getLiquidStatus(PhaseShift const& phaseShift, float x, float
         }
     }
 
-    if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(x, y))
+    if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(terrainMapId, x, y))
     {
         LiquidData map_data;
         ZLiquidStatus map_result = gmap->getLiquidStatus(x, y, z, ReqLiquidType, &map_data);
@@ -2786,9 +2844,9 @@ ZLiquidStatus Map::getLiquidStatus(PhaseShift const& phaseShift, float x, float
     return result;
 }
 
-float Map::GetWaterLevel(float x, float y) const
+float Map::GetWaterLevel(PhaseShift const& phaseShift, float x, float y) const
 {
-    if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(x, y))
+    if (GridMap* gmap = const_cast<Map*>(this)->GetGrid(phaseShift.GetTerrainMapId(GetId(), x, y), x, y))
         return gmap->getLiquidLevel(x, y);
     else
         return 0;
diff --git a/src/server/game/Maps/Map.h b/src/server/game/Maps/Map.h
index 065efc203ad..b2a0cb91551 100644
--- a/src/server/game/Maps/Map.h
+++ b/src/server/game/Maps/Map.h
@@ -198,7 +198,7 @@ class TC_GAME_API GridMap
     uint8 _liquidOffY;
     uint8 _liquidWidth;
     uint8 _liquidHeight;
-
+    bool _fileExists;
 
     bool loadAreaData(FILE* in, uint32 offset, uint32 size);
     bool loadHeightData(FILE* in, uint32 offset, uint32 size);
@@ -224,6 +224,7 @@ public:
     float getLiquidLevel(float x, float y) const;
     uint8 getTerrainType(float x, float y) const;
     ZLiquidStatus getLiquidStatus(float x, float y, float z, uint8 ReqLiquidType, LiquidData* data = 0);
+    bool fileExists() const { return _fileExists; }
 };
 
 #pragma pack(push, 1)
@@ -330,6 +331,8 @@ class TC_GAME_API Map : public GridRefManager<NGridType>
         static void DeleteStateMachine();
 
         Map const* GetParent() const { return m_parentMap; }
+        void AddChildTerrainMap(Map* map) { m_childTerrainMaps->push_back(map); }
+        void UnlinkAllChildTerrainMaps() { m_childTerrainMaps->clear(); }
 
         // some calls like isInWater should not use vmaps due to processor power
         // can return INVALID_HEIGHT if under z+2 z coord not found height
@@ -346,8 +349,8 @@ class TC_GAME_API Map : public GridRefManager<NGridType>
 
         bool IsOutdoors(PhaseShift const& phaseShift, float x, float y, float z) const;
 
-        uint8 GetTerrainType(float x, float y) const;
-        float GetWaterLevel(float x, float y) const;
+        uint8 GetTerrainType(PhaseShift const& phaseShift, float x, float y) const;
+        float GetWaterLevel(PhaseShift const& phaseShift, float x, float y) const;
         bool IsInWater(PhaseShift const& phaseShift, float x, float y, float z, LiquidData* data = nullptr) const;
         bool IsUnderWater(PhaseShift const& phaseShift, float x, float y, float z) const;
 
@@ -571,8 +574,11 @@ class TC_GAME_API Map : public GridRefManager<NGridType>
         void LoadMapAndVMap(int gx, int gy);
         void LoadVMap(int gx, int gy);
         void LoadMap(int gx, int gy, bool reload = false);
+        static void LoadMapImpl(Map* map, int gx, int gy, bool reload);
+        static void UnloadMap(Map* map, int gx, int gy);
         void LoadMMap(int gx, int gy);
         GridMap* GetGrid(float x, float y);
+        GridMap* GetGrid(uint32 mapId, float x, float y);
 
         void SetTimer(uint32 t) { i_gridExpiry = t < MIN_GRID_DELAY ? MIN_GRID_DELAY : t; }
 
@@ -672,6 +678,7 @@ class TC_GAME_API Map : public GridRefManager<NGridType>
         //used for fast base_map (e.g. MapInstanced class object) search for
         //InstanceMaps and BattlegroundMaps...
         Map* m_parentMap;
+        std::vector<Map*>* m_childTerrainMaps;
 
         NGridType* i_grids[MAX_NUMBER_OF_GRIDS][MAX_NUMBER_OF_GRIDS];
         GridMap* GridMaps[MAX_NUMBER_OF_GRIDS][MAX_NUMBER_OF_GRIDS];
diff --git a/src/server/game/Maps/MapManager.cpp b/src/server/game/Maps/MapManager.cpp
index d380e1be018..0b6bec91781 100644
--- a/src/server/game/Maps/MapManager.cpp
+++ b/src/server/game/Maps/MapManager.cpp
@@ -55,10 +55,15 @@ void MapManager::Initialize()
         m_updater.activate(num_threads);
 }
 
+void MapManager::InitializeParentMapData(std::unordered_map<uint32, std::vector<uint32>> const& mapData)
+{
+    _parentMapData = mapData;
+}
+
 void MapManager::InitializeVisibilityDistanceInfo()
 {
-    for (MapMapType::iterator iter=i_maps.begin(); iter != i_maps.end(); ++iter)
-        (*iter).second->InitVisibilityDistance();
+    for (auto iter = i_maps.begin(); iter != i_maps.end(); ++iter)
+        iter->second->InitVisibilityDistance();
 }
 
 MapManager* MapManager::instance()
@@ -71,29 +76,46 @@ Map* MapManager::CreateBaseMap(uint32 id)
 {
     Map* map = FindBaseMap(id);
 
-    if (map == NULL)
+    if (!map)
     {
-        std::lock_guard<std::mutex> lock(_mapsLock);
-
-        MapEntry const* entry = sMapStore.LookupEntry(id);
-        ASSERT(entry);
-
-        if (entry->Instanceable())
-            map = new MapInstanced(id, i_gridCleanUpDelay);
-        else
+        MapEntry const* entry = sMapStore.AssertEntry(id);
+        if (entry->ParentMapID != -1)
         {
-            map = new Map(id, i_gridCleanUpDelay, 0, DIFFICULTY_NONE);
-            map->LoadRespawnTimes();
-            map->LoadCorpseData();
+            CreateBaseMap(entry->ParentMapID);
+
+            // must have been created by parent map
+            map = FindBaseMap(id);
+            return ASSERT_NOTNULL(map);
         }
 
-        i_maps[id] = map;
+        std::lock_guard<std::mutex> lock(_mapsLock);
+        map = CreateBaseMap_i(entry);
     }
 
     ASSERT(map);
     return map;
 }
 
+Map* MapManager::CreateBaseMap_i(MapEntry const* mapEntry)
+{
+    Map* map;
+    if (mapEntry->Instanceable())
+        map = new MapInstanced(mapEntry->ID, i_gridCleanUpDelay);
+    else
+    {
+        map = new Map(mapEntry->ID, i_gridCleanUpDelay, 0, DIFFICULTY_NONE);
+        map->LoadRespawnTimes();
+        map->LoadCorpseData();
+    }
+
+    i_maps[mapEntry->ID] = map;
+
+    for (uint32 childMapId : _parentMapData[mapEntry->ID])
+        map->AddChildTerrainMap(CreateBaseMap_i(sMapStore.AssertEntry(childMapId)));
+
+    return map;
+}
+
 Map* MapManager::FindBaseNonInstanceMap(uint32 mapId) const
 {
     Map* map = FindBaseMap(mapId);
@@ -257,6 +279,10 @@ bool MapManager::IsValidMAP(uint32 mapid, bool startUp)
 
 void MapManager::UnloadAll()
 {
+    // first unlink child maps
+    for (auto iter = i_maps.begin(); iter != i_maps.end(); ++iter)
+        iter->second->UnlinkAllChildTerrainMaps();
+
     for (MapMapType::iterator iter = i_maps.begin(); iter != i_maps.end();)
     {
         iter->second->UnloadAll();
diff --git a/src/server/game/Maps/MapManager.h b/src/server/game/Maps/MapManager.h
index 892756db0d4..a8c4007118e 100644
--- a/src/server/game/Maps/MapManager.h
+++ b/src/server/game/Maps/MapManager.h
@@ -56,6 +56,7 @@ class TC_GAME_API MapManager
         }
 
         void Initialize(void);
+        void InitializeParentMapData(std::unordered_map<uint32, std::vector<uint32>> const& mapData);
         void Update(uint32);
 
         void SetGridCleanUpDelay(uint32 t)
@@ -145,8 +146,10 @@ class TC_GAME_API MapManager
             return (iter == i_maps.end() ? NULL : iter->second);
         }
 
-        MapManager(const MapManager &);
-        MapManager& operator=(const MapManager &);
+        Map* CreateBaseMap_i(MapEntry const* mapEntry);
+
+        MapManager(MapManager const&) = delete;
+        MapManager& operator=(MapManager const&) = delete;
 
         std::mutex _mapsLock;
         uint32 i_gridCleanUpDelay;
@@ -159,6 +162,9 @@ class TC_GAME_API MapManager
 
         // atomic op counter for active scripts amount
         std::atomic<std::size_t> _scheduledScripts;
+
+        // parent map links
+        std::unordered_map<uint32, std::vector<uint32>> _parentMapData;
 };
 
 template<typename Worker>
diff --git a/src/server/game/Phasing/PhasingHandler.cpp b/src/server/game/Phasing/PhasingHandler.cpp
index 08ed3f729b0..44f0a9ff753 100644
--- a/src/server/game/Phasing/PhasingHandler.cpp
+++ b/src/server/game/Phasing/PhasingHandler.cpp
@@ -31,6 +31,8 @@
 
 namespace
 {
+PhaseShift const Empty;
+
 inline PhaseFlags GetPhaseFlags(uint32 phaseId)
 {
     if (PhaseEntry const* phase = sPhaseStore.LookupEntry(phaseId))
@@ -420,6 +422,11 @@ void PhasingHandler::FillPartyMemberPhase(WorldPackets::Party::PartyMemberPhaseS
         [](PhaseShift::PhaseRef const& phase) -> WorldPackets::Party::PartyMemberPhase { return { phase.Flags.AsUnderlyingType(), phase.Id }; });
 }
 
+PhaseShift const& PhasingHandler::GetEmptyPhaseShift()
+{
+    return Empty;
+}
+
 void PhasingHandler::InitDbPhaseShift(PhaseShift& phaseShift, uint8 phaseUseFlags, uint16 phaseId, uint32 phaseGroupId)
 {
     phaseShift.ClearPhases();
diff --git a/src/server/game/Phasing/PhasingHandler.h b/src/server/game/Phasing/PhasingHandler.h
index e759f2e68e1..9ee408ad26c 100644
--- a/src/server/game/Phasing/PhasingHandler.h
+++ b/src/server/game/Phasing/PhasingHandler.h
@@ -55,6 +55,7 @@ public:
     static void SendToPlayer(Player const* player);
     static void FillPartyMemberPhase(WorldPackets::Party::PartyMemberPhaseStates* partyMemberPhases, PhaseShift const& phaseShift);
 
+    static PhaseShift const& GetEmptyPhaseShift();
     static void InitDbPhaseShift(PhaseShift& phaseShift, uint8 phaseUseFlags, uint16 phaseId, uint32 phaseGroupId);
     static void InitDbVisibleMapId(PhaseShift& phaseShift, int32 visibleMapId);
     static bool InDbPhaseShift(WorldObject const* object, uint8 phaseUseFlags, uint16 phaseId, uint32 phaseGroupId);
diff --git a/src/server/game/World/World.cpp b/src/server/game/World/World.cpp
index 125e9036e64..9e73cc8d532 100644
--- a/src/server/game/World/World.cpp
+++ b/src/server/game/World/World.cpp
@@ -1585,6 +1585,8 @@ void World::SetInitialWorldSettings()
             mapData[mapEntry->ParentMapID].push_back(mapEntry->ID);
     }
 
+    sMapMgr->InitializeParentMapData(mapData);
+
     if (VMAP::VMapManager2* vmmgr2 = dynamic_cast<VMAP::VMapManager2*>(VMAP::VMapFactory::createOrGetVMapManager()))
         vmmgr2->InitializeThreadUnsafe(mapData);
 
diff --git a/src/server/scripts/Commands/cs_go.cpp b/src/server/scripts/Commands/cs_go.cpp
index 09a31c885b7..cbd594f6682 100644
--- a/src/server/scripts/Commands/cs_go.cpp
+++ b/src/server/scripts/Commands/cs_go.cpp
@@ -29,6 +29,7 @@ EndScriptData */
 #include "MapManager.h"
 #include "MotionMaster.h"
 #include "ObjectMgr.h"
+#include "PhasingHandler.h"
 #include "Player.h"
 #include "RBAC.h"
 #include "SupportMgr.h"
@@ -247,7 +248,7 @@ public:
             player->SaveRecallPosition();
 
         Map const* map = sMapMgr->CreateBaseMap(mapId);
-        float z = std::max(map->GetStaticHeight(PhaseShift(), x, y, MAX_HEIGHT), map->GetWaterLevel(x, y));
+        float z = std::max(map->GetStaticHeight(PhasingHandler::GetEmptyPhaseShift(), x, y, MAX_HEIGHT), map->GetWaterLevel(PhasingHandler::GetEmptyPhaseShift(), x, y));
 
         player->TeleportTo(mapId, x, y, z, player->GetOrientation());
         return true;
@@ -369,7 +370,7 @@ public:
             player->SaveRecallPosition();
 
         Map const* map = sMapMgr->CreateBaseMap(mapId);
-        z = std::max(map->GetStaticHeight(PhaseShift(), x, y, MAX_HEIGHT), map->GetWaterLevel(x, y));
+        z = std::max(map->GetStaticHeight(PhasingHandler::GetEmptyPhaseShift(), x, y, MAX_HEIGHT), map->GetWaterLevel(PhasingHandler::GetEmptyPhaseShift(), x, y));
 
         player->TeleportTo(mapId, x, y, z, 0.0f);
         return true;
@@ -532,7 +533,7 @@ public:
         else
             player->SaveRecallPosition();
 
-        float z = std::max(map->GetStaticHeight(PhaseShift(), x, y, MAX_HEIGHT), map->GetWaterLevel(x, y));
+        float z = std::max(map->GetStaticHeight(PhasingHandler::GetEmptyPhaseShift(), x, y, MAX_HEIGHT), map->GetWaterLevel(PhasingHandler::GetEmptyPhaseShift(), x, y));
 
         player->TeleportTo(zoneEntry->ContinentID, x, y, z, player->GetOrientation());
         return true;
@@ -580,7 +581,7 @@ public:
                 return false;
             }
             Map const* map = sMapMgr->CreateBaseMap(mapId);
-            z = std::max(map->GetStaticHeight(PhaseShift(), x, y, MAX_HEIGHT), map->GetWaterLevel(x, y));
+            z = std::max(map->GetStaticHeight(PhasingHandler::GetEmptyPhaseShift(), x, y, MAX_HEIGHT), map->GetWaterLevel(PhasingHandler::GetEmptyPhaseShift(), x, y));
         }
 
         // stop flight if need
diff --git a/src/server/scripts/Commands/cs_tele.cpp b/src/server/scripts/Commands/cs_tele.cpp
index 79113971fe4..658a0ed446b 100644
--- a/src/server/scripts/Commands/cs_tele.cpp
+++ b/src/server/scripts/Commands/cs_tele.cpp
@@ -31,6 +31,7 @@ EndScriptData */
 #include "MapManager.h"
 #include "MotionMaster.h"
 #include "ObjectMgr.h"
+#include "PhasingHandler.h"
 #include "Player.h"
 #include "RBAC.h"
 #include "WorldSession.h"
@@ -207,7 +208,7 @@ public:
 
             SQLTransaction dummy;
             Player::SavePositionInDB(WorldLocation(tele->mapId, tele->position_x, tele->position_y, tele->position_z, tele->orientation),
-                sMapMgr->GetZoneId(PhaseShift(), tele->mapId, tele->position_x, tele->position_y, tele->position_z), target_guid, dummy);
+                sMapMgr->GetZoneId(PhasingHandler::GetEmptyPhaseShift(), tele->mapId, tele->position_x, tele->position_y, tele->position_z), target_guid, dummy);
         }
 
         return true;
diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/instance_the_black_morass.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/instance_the_black_morass.cpp
index 1bfd96f0e35..7154bd11a9d 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/instance_the_black_morass.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/instance_the_black_morass.cpp
@@ -272,7 +272,7 @@ public:
             Position pos = me->GetRandomNearPosition(10.0f);
 
             //normalize Z-level if we can, if rift is not at ground level.
-            pos.m_positionZ = std::max(me->GetMap()->GetHeight(me->GetPhaseShift(), pos.m_positionX, pos.m_positionY, MAX_HEIGHT), me->GetMap()->GetWaterLevel(pos.m_positionX, pos.m_positionY));
+            pos.m_positionZ = std::max(me->GetMap()->GetHeight(me->GetPhaseShift(), pos.m_positionX, pos.m_positionY, MAX_HEIGHT), me->GetMap()->GetWaterLevel(me->GetPhaseShift(), pos.m_positionX, pos.m_positionY));
 
             if (Creature* summon = me->SummonCreature(entry, pos, TEMPSUMMON_TIMED_OR_DEAD_DESPAWN, 600000))
                 return summon;
diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
index 64c8bb0db1d..2f6b624bc08 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
@@ -309,7 +309,7 @@ public:
             Position pos = me->GetRandomNearPosition(10.0f);
 
             //normalize Z-level if we can, if rift is not at ground level.
-            pos.m_positionZ = std::max(me->GetMap()->GetHeight(me->GetPhaseShift(), pos.m_positionX, pos.m_positionY, MAX_HEIGHT), me->GetMap()->GetWaterLevel(pos.m_positionX, pos.m_positionY));
+            pos.m_positionZ = std::max(me->GetMap()->GetHeight(me->GetPhaseShift(), pos.m_positionX, pos.m_positionY, MAX_HEIGHT), me->GetMap()->GetWaterLevel(me->GetPhaseShift(), pos.m_positionX, pos.m_positionY));
 
             if (Unit* Summon = DoSummon(creature_entry, pos, 30000, TEMPSUMMON_TIMED_DESPAWN_OUT_OF_COMBAT))
                 if (Unit* temp = ObjectAccessor::GetUnit(*me, instance->GetGuidData(DATA_MEDIVH)))