path: root/source/cChunkMap.cpp

#include "Globals.h"  // NOTE: MSVC stupidness requires this to be the same across all modules

#include "cChunkMap.h"
#include "cWorld.h"
#include "cRoot.h"
#include "cMakeDir.h"
#include "cPlayer.h"
#include "BlockID.h"
#include "cItem.h"
#include "cPickup.h"

#ifndef _WIN32
	#include <cstdlib> // abs
#endif

#include "zlib.h"
#include <json/json.h>





#define RECI_RAND_MAX (1.f/RAND_MAX)
inline float fRadRand( float a_Radius )
{
	MTRand r1;
	return ((float)r1.rand() * RECI_RAND_MAX)*a_Radius - a_Radius*0.5f;
}





////////////////////////////////////////////////////////////////////////////////
// cChunkMap:

cChunkMap::cChunkMap(cWorld * a_World )
	: m_World( a_World )
{
}





cChunkMap::~cChunkMap()
{
	cCSLock Lock(m_CSLayers);
	for (cChunkLayerList::iterator itr = m_Layers.begin(); itr != m_Layers.end(); ++itr)
	{
		delete *itr;
	}  // for itr - m_Layers[]
}





void cChunkMap::RemoveLayer( cChunkLayer* a_Layer )
{
	cCSLock Lock(m_CSLayers);
	m_Layers.remove(a_Layer);
}





cChunkMap::cChunkLayer * cChunkMap::GetLayer(int a_LayerX, int a_LayerZ)
{
	cCSLock Lock(m_CSLayers);
	for (cChunkLayerList::const_iterator itr = m_Layers.begin(); itr != m_Layers.end(); ++itr)
	{
		if (((*itr)->GetX() == a_LayerX) && ((*itr)->GetZ() == a_LayerZ))
		{
			return *itr;
		}
	}
	
	// Not found, create new:
	cChunkLayer * Layer = new cChunkLayer(a_LayerX, a_LayerZ, this);
	if (Layer == NULL)
	{
		LOGERROR("cChunkMap: Cannot create new layer, server out of memory?");
		return NULL;
	}
	m_Layers.push_back(Layer);
	return Layer;
}





cChunkMap::cChunkLayer * cChunkMap::GetLayerForChunk( int a_ChunkX, int a_ChunkZ )
{
	const int LayerX = (int)(floorf((float)a_ChunkX / (float)(LAYER_SIZE)));
	const int LayerZ = (int)(floorf((float)a_ChunkZ / (float)(LAYER_SIZE)));
	return GetLayer( LayerX, LayerZ );
}





cChunkPtr cChunkMap::GetChunk( int a_ChunkX, int a_ChunkY, int a_ChunkZ )
{
	// No need to lock m_CSLayers, since it's already locked by the operation that called us
	cChunkLayer * Layer = GetLayerForChunk( a_ChunkX, a_ChunkZ );
	if (Layer == NULL)
	{
		// An error must have occurred, since layers are automatically created if they don't exist
		return NULL;
	}
	
	cChunkPtr Chunk = Layer->GetChunk(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (Chunk == NULL)
	{
		return NULL;
	}
	if (!(Chunk->IsValid()))
	{
		m_World->GetStorage().QueueLoadChunk(a_ChunkX, a_ChunkY, a_ChunkZ, true);
	}
	return Chunk;
}





cChunkPtr cChunkMap::GetChunkNoGen( int a_ChunkX, int a_ChunkY, int a_ChunkZ )
{
	// No need to lock m_CSLayers, since it's already locked by the operation that called us
	cChunkLayer * Layer = GetLayerForChunk( a_ChunkX, a_ChunkZ );
	if (Layer == NULL)
	{
		// An error must have occurred, since layers are automatically created if they don't exist
		return NULL;
	}
	
	cChunkPtr Chunk = Layer->GetChunk(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (Chunk == NULL)
	{
		return NULL;
	}
	if (!(Chunk->IsValid()))
	{
		m_World->GetStorage().QueueLoadChunk(a_ChunkX, a_ChunkY, a_ChunkZ, false);
	}
	
	return Chunk;
}





cChunkPtr cChunkMap::GetChunkNoLoad( int a_ChunkX, int a_ChunkY, int a_ChunkZ )
{
	// No need to lock m_CSLayers, since it's already locked by the operation that called us
	cChunkLayer * Layer = GetLayerForChunk( a_ChunkX, a_ChunkZ );
	if (Layer == NULL)
	{
		// An error must have occurred, since layers are automatically created if they don't exist
		return NULL;
	}
	
	return Layer->GetChunk(a_ChunkX, a_ChunkY, a_ChunkZ);
}





void cChunkMap::BroadcastToChunk(int a_ChunkX, int a_ChunkY, int a_ChunkZ, const cPacket & a_Packet, cClientHandle * a_Exclude)
{
	// Broadcasts a_Packet to all clients in the chunk where block [x, y, z] is, except to client a_Exclude
	
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (Chunk == NULL)
	{
		return;
	}
	// It's perfectly legal to broadcast packets even to invalid chunks!
	Chunk->Broadcast(a_Packet, a_Exclude);
}





void cChunkMap::BroadcastToChunkOfBlock(int a_X, int a_Y, int a_Z, const cPacket * a_Packet, cClientHandle * a_Exclude)
{
	// Broadcasts a_Packet to all clients in the chunk where block [x, y, z] is, except to client a_Exclude
	
	cCSLock Lock(m_CSLayers);
	int ChunkX, ChunkZ;
	BlockToChunk(a_X, a_Y, a_Z, ChunkX, ChunkZ);
	cChunkPtr Chunk = GetChunkNoGen(ChunkX, ZERO_CHUNK_Y, ChunkZ);
	if (Chunk == NULL)
	{
		return;
	}
	// It's perfectly legal to broadcast packets even to invalid chunks!
	Chunk->Broadcast(a_Packet, a_Exclude);
}





void cChunkMap::UseBlockEntity(cPlayer * a_Player, int a_X, int a_Y, int a_Z)
{
	// a_Player rclked block entity at the coords specified, handle it
	cCSLock Lock(m_CSLayers);
	int ChunkX, ChunkZ;
	BlockToChunk(a_X, a_Y, a_Z, ChunkX, ChunkZ);
	cChunkPtr Chunk = GetChunkNoGen(ChunkX, 0, ChunkZ);
	if ((Chunk == NULL) || !Chunk->IsValid())
	{
		return;
	}
	Chunk->UseBlockEntity(a_Player, a_X, a_Y, a_Z);
}





void cChunkMap::MarkChunkDirty (int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if ((Chunk == NULL) || !Chunk->IsValid())
	{
		return;
	}
	Chunk->MarkDirty();
}





void cChunkMap::MarkChunkSaving(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if ((Chunk == NULL) || !Chunk->IsValid())
	{
		return;
	}
	Chunk->MarkSaving();
}





void cChunkMap::MarkChunkSaved (int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if ((Chunk == NULL) || !Chunk->IsValid())
	{
		return;
	}
	Chunk->MarkSaved();
}





void cChunkMap::ChunkDataLoaded(int a_ChunkX, int a_ChunkY, int a_ChunkZ, const char * a_BlockData, cEntityList & a_Entities, cBlockEntityList & a_BlockEntities)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoLoad(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (Chunk == NULL)
	{
		return;
	}
	Chunk->SetAllData(a_BlockData, a_Entities, a_BlockEntities);
	Chunk->MarkLoaded();
}





void cChunkMap::ChunkDataGenerated(int a_ChunkX, int a_ChunkY, int a_ChunkZ, const char * a_BlockData, cEntityList & a_Entities, cBlockEntityList & a_BlockEntities)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoLoad(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (Chunk == NULL)
	{
		return;
	}
	Chunk->SetAllData(a_BlockData, a_Entities, a_BlockEntities);

	// TODO: This has to go - lighting takes way too long to execute in a locked ChunkMap!
	Chunk->CalculateLighting();
	
	Chunk->SetValid();
	Chunk->MarkDirty();
}





void cChunkMap::GetChunkData(int a_ChunkX, int a_ChunkY, int a_ChunkZ, cChunkDataCallback * a_Callback)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if ((Chunk == NULL) || !Chunk->IsValid())
	{
		return;
	}
	Chunk->GetAllData(a_Callback);
}





bool cChunkMap::GetChunkBlocks(int a_ChunkX, int a_ChunkY, int a_ChunkZ, char * a_Blocks)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if ((Chunk == NULL) || !Chunk->IsValid())
	{
		return false;
	}
	Chunk->GetBlocks(a_Blocks);
	return true;
}





bool cChunkMap::IsChunkValid(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoLoad(a_ChunkX, a_ChunkY, a_ChunkZ);
	return (Chunk != NULL) && Chunk->IsValid();
}





bool cChunkMap::HasChunkAnyClients(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	return (Chunk != NULL) && Chunk->HasAnyClients();
}





void cChunkMap::SpreadChunkLighting(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if ((Chunk != NULL) && Chunk->IsValid())
	{
		// TODO: Rewrite this to call Chunk's lighting without any parameters
		Chunk->SpreadLight( Chunk->pGetSkyLight() );
		Chunk->SpreadLight( Chunk->pGetLight() );
	}
}





int  cChunkMap::GetHeight(int a_BlockX, int a_BlockZ)
{
	cCSLock Lock(m_CSLayers);
	int ChunkX, ChunkZ, BlockY = 0;
	AbsoluteToRelative(a_BlockX, BlockY, a_BlockZ, ChunkX, ChunkZ);
	cChunkPtr Chunk = GetChunk(ChunkX, ZERO_CHUNK_Y, ChunkZ);
	if (Chunk == NULL)
	{
		return 0;
	}
	
	// Wait for the chunk to become valid:
	while (!Chunk->IsValid())
	{
		GetChunk(ChunkX, ZERO_CHUNK_Y, ChunkZ);  // Re-queue (in case it managed to get unloaded before we caught it
		cCSUnlock Unlock(Lock);
		m_evtChunkValid.Wait();
	}
	
	return Chunk->GetHeight(a_BlockX, a_BlockZ);
}





void cChunkMap::FastSetBlocks(sSetBlockList & a_BlockList)
{
	sSetBlockList Failed;
	
	// Process all items from a_BlockList, either successfully or by placing into Failed
	while (!a_BlockList.empty())
	{
		int ChunkX = a_BlockList.front().ChunkX;
		int ChunkZ = a_BlockList.front().ChunkZ;
		cCSLock Lock(m_CSLayers);
		cChunkPtr Chunk = GetChunkNoGen(ChunkX, ZERO_CHUNK_Y, ChunkZ);
		if ((Chunk != NULL) && Chunk->IsValid())
		{
			for (sSetBlockList::iterator itr = a_BlockList.begin(); itr != a_BlockList.end();)
			{
				if ((itr->ChunkX == ChunkX) && (itr->ChunkZ == ChunkZ))
				{
					Chunk->FastSetBlock(itr->x, itr->y, itr->z, itr->BlockType, itr->BlockMeta);
					itr = a_BlockList.erase(itr);
				}
				else
				{
					++itr;
				}
			}  // for itr - a_BlockList[]
		}
		else
		{
			// The chunk is not valid, move all blocks within this chunk to Failed
			for (sSetBlockList::iterator itr = a_BlockList.begin(); itr != a_BlockList.end();)
			{
				if ((itr->ChunkX == ChunkX) && (itr->ChunkZ == ChunkZ))
				{
					Failed.push_back(*itr);
					itr = a_BlockList.erase(itr);
				}
				else
				{
					++itr;
				}
			}  // for itr - a_BlockList[]
		}
	}
	
	// Return the failed:
	std::swap(Failed, a_BlockList);
}





void cChunkMap::CollectPickupsByPlayer(cPlayer * a_Player)
{
	int BlockX = (int)(a_Player->GetPosX());  // Truncating doesn't matter much; we're scanning entire chunks anyway
	int BlockY = (int)(a_Player->GetPosY());
	int BlockZ = (int)(a_Player->GetPosZ());
	int ChunkX, ChunkZ, ChunkY = ZERO_CHUNK_Y;
	AbsoluteToRelative(BlockX, BlockY, BlockZ, ChunkX, ChunkZ);
	int OtherChunkX = ChunkX + ((BlockX > 8) ? 1 : -1);
	int OtherChunkZ = ChunkZ + ((BlockZ > 8) ? 1 : -1);
	
	cCSLock Lock(m_CSLayers);
	GetChunkNoGen(ChunkX, ChunkY, ChunkZ)->CollectPickupsByPlayer(a_Player);

	// Check the neighboring chunks as well:
	GetChunkNoGen(OtherChunkX, ChunkY, ChunkZ     )->CollectPickupsByPlayer(a_Player);
	GetChunkNoGen(OtherChunkX, ChunkY, OtherChunkZ)->CollectPickupsByPlayer(a_Player);
	GetChunkNoGen(ChunkX,      ChunkY, ChunkZ     )->CollectPickupsByPlayer(a_Player);
	GetChunkNoGen(ChunkX,      ChunkY, OtherChunkZ)->CollectPickupsByPlayer(a_Player);
}





char cChunkMap::GetBlock(int a_X, int a_Y, int a_Z)
{
	int ChunkX, ChunkZ;
	AbsoluteToRelative( a_X, a_Y, a_Z, ChunkX, ChunkZ );
	
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunk(ChunkX, ZERO_CHUNK_Y, ChunkZ);
	if ((Chunk != NULL) && Chunk->IsValid())
	{
		return Chunk->GetBlock(a_X, a_Y, a_Z);
	}
	return 0;
}





char cChunkMap::GetBlockMeta(int a_X, int a_Y, int a_Z)
{
	int ChunkX, ChunkZ;
	AbsoluteToRelative( a_X, a_Y, a_Z, ChunkX, ChunkZ );
	
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunk( ChunkX, ZERO_CHUNK_Y, ChunkZ );
	if ((Chunk != NULL) && Chunk->IsValid() )
	{
		// Although it is called GetLight(), it actually gets meta when passed the Meta field
		return Chunk->GetLight( Chunk->pGetMeta(), a_X, a_Y, a_Z );
	}
	return 0;
}





void cChunkMap::SetBlockMeta(int a_X, int a_Y, int a_Z, char a_BlockMeta)
{
	int ChunkX, ChunkZ;
	AbsoluteToRelative( a_X, a_Y, a_Z, ChunkX, ChunkZ );

	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunk( ChunkX, ZERO_CHUNK_Y, ChunkZ );
	if ((Chunk != NULL) && Chunk->IsValid() )	
	{
		// Although it is called SetLight(), it actually sets meta when passed the Meta field
		Chunk->SetLight( Chunk->pGetMeta(), a_X, a_Y, a_Z, a_BlockMeta );
		Chunk->SendBlockTo( a_X, a_Y, a_Z, NULL );
	}
}





void cChunkMap::SetBlock(int a_X, int a_Y, int a_Z, char a_BlockType, char a_BlockMeta)
{
	int ChunkX, ChunkZ, X = a_X, Y = a_Y, Z = a_Z;
	AbsoluteToRelative( X, Y, Z, ChunkX, ChunkZ );

	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunk( ChunkX, ZERO_CHUNK_Y, ChunkZ );
	if ((Chunk != NULL) && Chunk->IsValid())
	{
		Chunk->SetBlock(X, Y, Z, a_BlockType, a_BlockMeta );
	}
}





bool cChunkMap::DigBlock(int a_X, int a_Y, int a_Z, cItem & a_PickupItem)
{
	int PosX = a_X, PosY = a_Y, PosZ = a_Z, ChunkX, ChunkZ;

	AbsoluteToRelative( PosX, PosY, PosZ, ChunkX, ChunkZ );

	{
		cCSLock Lock(m_CSLayers);
		cChunkPtr DestChunk = GetChunk( ChunkX, ZERO_CHUNK_Y, ChunkZ );
		if ((DestChunk == NULL) || !DestChunk->IsValid())
		{
			return false;
		}
		
		DestChunk->SetBlock(PosX, PosY, PosZ, E_BLOCK_AIR, 0 );
	}

	m_World->GetSimulatorManager()->WakeUp(a_X, a_Y, a_Z);

	if ( !a_PickupItem.IsEmpty() )
	{
		cPickup * Pickup = new cPickup( a_X * 32 + 16 + (int)fRadRand(16.f), a_Y * 32 + 16 + (int)fRadRand(16.f), a_Z * 32 + 16 + (int)fRadRand(16.f), a_PickupItem );
		Pickup->Initialize(m_World);
	}
	return true;
}





void cChunkMap::SendBlockTo(int a_X, int a_Y, int a_Z, cPlayer * a_Player)
{
	int ChunkX, ChunkZ;
	AbsoluteToRelative(a_X, a_Y, a_Z, ChunkX, ChunkZ);
	
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunk(ChunkX, ZERO_CHUNK_Y, ChunkZ);
	if (Chunk->IsValid())
	{
		Chunk->SendBlockTo(a_X, a_Y, a_Z, a_Player->GetClientHandle());
	}
}





void cChunkMap::CompareChunkClients(int a_ChunkX1, int a_ChunkY1, int a_ChunkZ1, int a_ChunkX2, int a_ChunkY2, int a_ChunkZ2, cClientDiffCallback & a_Callback)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk1 = GetChunkNoGen(a_ChunkX1, a_ChunkY1, a_ChunkZ1);
	if (Chunk1 == NULL)
	{
		return;
	}
	cChunkPtr Chunk2 = GetChunkNoGen(a_ChunkX2, a_ChunkY2, a_ChunkZ2);
	if (Chunk2 == NULL)
	{
		return;
	}

	cClientHandleList Clients1(Chunk1->GetAllClients());
	cClientHandleList Clients2(Chunk2->GetAllClients());
	
	// Find "removed" clients:
	for (cClientHandleList::iterator itr1 = Clients1.begin(); itr1 != Clients1.end(); ++itr1)
	{
		bool Found = false;
		for (cClientHandleList::iterator itr2 = Clients2.begin(); itr2 != Clients2.end(); ++itr2)
		{
			if (*itr1 == *itr2)
			{
				Found = true;
				break;
			}
		}  // for itr2 - Clients2[]
		if (!Found)
		{
			a_Callback.Removed(*itr1);
		}
	}  // for itr1 - Clients1[]
	
	// Find "added" clients:
	for (cClientHandleList::iterator itr2 = Clients2.begin(); itr2 != Clients2.end(); ++itr2)
	{
		bool Found = false;
		for (cClientHandleList::iterator itr1 = Clients1.begin(); itr1 != Clients1.end(); ++itr1)
		{
			if (*itr1 == *itr2)
			{
				Found = true;
				break;
			}
		}  // for itr1 - Clients1[]
		if (!Found)
		{
			a_Callback.Added(*itr2);
		}
	}  // for itr2 - Clients2[]
}





bool cChunkMap::AddChunkClient(int a_ChunkX, int a_ChunkY, int a_ChunkZ, cClientHandle * a_Client)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunk(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (Chunk == NULL)
	{
		return false;
	}
	return Chunk->AddClient(a_Client);
}





void cChunkMap::RemoveChunkClient(int a_ChunkX, int a_ChunkY, int a_ChunkZ, cClientHandle * a_Client)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (Chunk == NULL)
	{
		return;
	}
	Chunk->RemoveClient(a_Client);
}





void cChunkMap::RemoveClientFromChunks(cClientHandle * a_Client, const cChunkCoordsList & a_Chunks)
{
	cCSLock Lock(m_CSLayers);
	
	for (cChunkCoordsList::const_iterator itr = a_Chunks.begin(); itr != a_Chunks.end(); ++itr)
	{
		GetChunkNoGen(itr->m_ChunkX, itr->m_ChunkY, itr->m_ChunkZ)->RemoveClient(a_Client);
	}
}





bool cChunkMap::SendChunkTo(int a_ChunkX, int a_ChunkY, int a_ChunkZ, cClientHandle * a_Client)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if ((Chunk == NULL) || !Chunk->IsValid())
	{
		return false;
	}
	Chunk->SendTo(a_Client);
	return true;
}





void cChunkMap::MoveEntityToChunk(cEntity * a_Entity, int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr OldChunk = GetChunkNoGen(a_Entity->GetChunkX(), a_Entity->GetChunkY(), a_Entity->GetChunkZ());
	if (OldChunk != NULL)
	{
		OldChunk->RemoveEntity(a_Entity);
	}
	cChunkPtr NewChunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (NewChunk != NULL)
	{
		NewChunk->AddEntity(a_Entity);
	}
}





void cChunkMap::RemoveEntityFromChunk(cEntity * a_Entity, int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
	if ((Chunk == NULL) && !Chunk->IsValid())
	{
		return;
	}
	Chunk->RemoveEntity(a_Entity);
}





void cChunkMap::TouchChunk(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	GetChunk(a_ChunkX, a_ChunkY, a_ChunkZ);
}





/// Loads the chunk synchronously, if not already loaded. Doesn't generate. Returns true if chunk valid (even if already loaded before)
bool cChunkMap::LoadChunk(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	{
		cCSLock Lock(m_CSLayers);
		cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
		if (Chunk == NULL)
		{
			// Internal error
			return false;
		}
		if (Chunk->IsValid())
		{
			// Already loaded
			return true;
		}
		if (Chunk->HasLoadFailed())
		{
			// Already tried loading and it failed
			return false;
		}
	}
	return m_World->GetStorage().LoadChunk(a_ChunkX, a_ChunkY, a_ChunkZ);
}





/// Loads the chunks specified. Doesn't report failure, other than chunks being !IsValid()
void cChunkMap::LoadChunks(const cChunkCoordsList & a_Chunks)
{
	for (cChunkCoordsList::const_iterator itr = a_Chunks.begin(); itr != a_Chunks.end(); ++itr)
	{
		LoadChunk(itr->m_ChunkX, itr->m_ChunkY, itr->m_ChunkZ);
	}  // for itr - a_Chunks[]
}





void cChunkMap::ChunkLoadFailed(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	cCSLock Lock(m_CSLayers);
	cChunkPtr Chunk = GetChunkNoLoad(a_ChunkX, a_ChunkY, a_ChunkZ);
	if (Chunk == NULL)
	{
		return;
	}
	Chunk->MarkLoadFailed();
}





void cChunkMap::UpdateSign(int a_X, int a_Y, int a_Z, const AString & a_Line1, const AString & a_Line2, const AString & a_Line3, const AString & a_Line4)
{
	cCSLock Lock(m_CSLayers);
	int ChunkX, ChunkZ;
	BlockToChunk(a_X, a_Y, a_Z, ChunkX, ChunkZ);
	cChunkPtr Chunk = GetChunkNoGen(ChunkX, ZERO_CHUNK_Y, ChunkZ);
	if ((Chunk == NULL) || !Chunk->IsValid())
	{
		return;
	}
	Chunk->UpdateSign(a_X, a_Y, a_Z, a_Line1, a_Line2, a_Line3, a_Line4);
}





void cChunkMap::ChunksStay(const cChunkCoordsList & a_Chunks, bool a_Stay)
{
	cCSLock Lock(m_CSLayers);
	for (cChunkCoordsList::const_iterator itr = a_Chunks.begin(); itr != a_Chunks.end(); ++itr)
	{
		cChunkPtr Chunk = GetChunkNoLoad(itr->m_ChunkX, itr->m_ChunkY, itr->m_ChunkZ);
		if (Chunk == NULL)
		{
			continue;
		}
		Chunk->Stay(a_Stay);
	}
}





void cChunkMap::Tick( float a_Dt, MTRand & a_TickRandom )
{
	cCSLock Lock(m_CSLayers);
	for (cChunkLayerList::iterator itr = m_Layers.begin(); itr != m_Layers.end(); ++itr)
	{
		(*itr)->Tick(a_Dt, a_TickRandom);
	}  // for itr - m_Layers
}





void cChunkMap::UnloadUnusedChunks()
{
	cCSLock Lock(m_CSLayers);
	for (cChunkLayerList::iterator itr = m_Layers.begin(); itr != m_Layers.end(); ++itr)
	{
		(*itr)->UnloadUnusedChunks();
	}  // for itr - m_Layers
}





void cChunkMap::SaveAllChunks(void)
{
	cCSLock Lock(m_CSLayers);
	for (cChunkLayerList::iterator itr = m_Layers.begin(); itr != m_Layers.end(); ++itr)
	{
		(*itr)->Save();
	}  // for itr - m_Layers[]
}





////////////////////////////////////////////////////////////////////////////////
// cChunkMap::cChunkLayer:

cChunkMap::cChunkLayer::cChunkLayer(int a_LayerX, int a_LayerZ, cChunkMap * a_Parent)
	: m_LayerX( a_LayerX )
	, m_LayerZ( a_LayerZ )
	, m_Parent( a_Parent )
	, m_NumChunksLoaded( 0 )
{
	memset(m_Chunks, 0, sizeof(m_Chunks));
}





cChunkMap::cChunkLayer::~cChunkLayer()
{
	for (int i = 0; i < ARRAYCOUNT(m_Chunks); ++i)
	{
		delete m_Chunks[i];
	}  // for i - m_Chunks[]
}





cChunkPtr cChunkMap::cChunkLayer::GetChunk( int a_ChunkX, int a_ChunkY, int a_ChunkZ )
{
	// Always returns an assigned chunkptr, but the chunk needn't be valid (loaded / generated) - callers must check

	const int LocalX = a_ChunkX - m_LayerX * LAYER_SIZE;
	const int LocalZ = a_ChunkZ - m_LayerZ * LAYER_SIZE;
	
	
	if (!((LocalX < LAYER_SIZE) && (LocalZ < LAYER_SIZE) && (LocalX > -1) && (LocalZ > -1)))
	{
		ASSERT(!"Asking a cChunkLayer for a chunk that doesn't belong to it!");
		return NULL;
	}
	
	int Index = LocalX + LocalZ * LAYER_SIZE;
	if (m_Chunks[Index] == NULL)
	{
		m_Chunks[Index] = new cChunk(a_ChunkX, 0, a_ChunkZ, m_Parent, m_Parent->GetWorld());
	}
	return m_Chunks[Index];
}





void cChunkMap::cChunkLayer::Tick(float a_Dt, MTRand & a_TickRand)
{
	for (int i = 0; i < ARRAYCOUNT(m_Chunks); i++)
	{
		// Only tick chunks that are valid and have clients:
		if ((m_Chunks[i] != NULL) && m_Chunks[i]->IsValid() && m_Chunks[i]->HasAnyClients())
		{
			m_Chunks[i]->Tick(a_Dt, a_TickRand);
		}
	}  // for i - m_Chunks[]
}





int cChunkMap::cChunkLayer::GetNumChunksLoaded(void) const
{
	int NumChunks = 0;
	for ( int i = 0; i < ARRAYCOUNT(m_Chunks); ++i )
	{
		if (m_Chunks[i] != NULL)
		{
			NumChunks++;
		}
	}  // for i - m_Chunks[]
	return NumChunks; 
}





void cChunkMap::cChunkLayer::Save(void)
{
	cWorld * World = m_Parent->GetWorld();
	for (int i = 0; i < ARRAYCOUNT(m_Chunks); ++i)
	{
		if ((m_Chunks[i] != NULL) && m_Chunks[i]->IsValid() && m_Chunks[i]->IsDirty())
		{
			World->GetStorage().QueueSaveChunk(m_Chunks[i]->GetPosX(), m_Chunks[i]->GetPosY(), m_Chunks[i]->GetPosZ());
		}
	}  // for i - m_Chunks[]
}





void cChunkMap::cChunkLayer::UnloadUnusedChunks(void)
{
	for (int i = 0; i < ARRAYCOUNT(m_Chunks); i++)
	{
		if ((m_Chunks[i] != NULL) && (m_Chunks[i]->CanUnload()))
		{
			// The cChunk destructor calls our GetChunk() while removing its entities
			// so we still need to be able to return the chunk. Therefore we first delete, then NULLify
			// Doing otherwise results in bug http://forum.mc-server.org/showthread.php?tid=355
			delete m_Chunks[i];
			m_Chunks[i] = NULL;
		}
	}  // for i - m_Chunks[]
}





int cChunkMap::GetNumChunks(void)
{
	cCSLock Lock(m_CSLayers);
	int NumChunks = 0;
	for (cChunkLayerList::iterator itr = m_Layers.begin(); itr != m_Layers.end(); ++itr)
	{
		NumChunks += (*itr)->GetNumChunksLoaded();
	}
	return NumChunks;
}





void cChunkMap::ChunkValidated(void)
{
	m_evtChunkValid.Set();
}





///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// cChunkStay:

cChunkStay::cChunkStay(cWorld * a_World) :
	m_World(a_World),
	m_IsEnabled(false)
{
}





cChunkStay::~cChunkStay()
{
	Clear();
}





void cChunkStay::Clear(void)
{
	if (m_IsEnabled)
	{
		Disable();
	}
	m_Chunks.clear();
}





void cChunkStay::Add(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	ASSERT(!m_IsEnabled);

	for (cChunkCoordsList::const_iterator itr = m_Chunks.begin(); itr != m_Chunks.end(); ++itr)
	{
		if ((itr->m_ChunkX == a_ChunkX) && (itr->m_ChunkY == a_ChunkY) && (itr->m_ChunkZ == a_ChunkZ))
		{
			// Already present
			return;
		}
	}  // for itr - Chunks[]
	m_Chunks.push_back(cChunkCoords(a_ChunkX, a_ChunkY, a_ChunkZ));
}





void cChunkStay::Remove(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
{
	ASSERT(!m_IsEnabled);

	for (cChunkCoordsList::const_iterator itr = m_Chunks.begin(); itr != m_Chunks.end(); ++itr)
	{
		if ((itr->m_ChunkX == a_ChunkX) && (itr->m_ChunkY == a_ChunkY) && (itr->m_ChunkZ == a_ChunkZ))
		{
			// Found, un-"stay"
			m_Chunks.erase(itr);
			return;
		}
	}  // for itr - Chunks[]
}





void cChunkStay::Enable(void)
{
	ASSERT(!m_IsEnabled);
	
	m_World->ChunksStay(*this, true);
	m_IsEnabled = true;
}





void cChunkStay::Disable(void)
{
	ASSERT(m_IsEnabled);
	
	m_World->ChunksStay(*this, false);
	m_IsEnabled = false;
}