コード例 #1
0
ファイル: Monster.cpp プロジェクト: gjzskyland/cuberite
void cMonster::InStateIdle(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
{
	if (m_PathfinderActivated)
	{
		return;  // Still getting there
	}

	m_IdleInterval += a_Dt;

	if (m_IdleInterval > std::chrono::seconds(1))
	{
		// At this interval the results are predictable
		int rem = m_World->GetTickRandomNumber(6) + 1;
		m_IdleInterval -= std::chrono::seconds(1);  // So nothing gets dropped when the server hangs for a few seconds

		Vector3d Dist;
		Dist.x = static_cast<double>(m_World->GetTickRandomNumber(10)) - 5.0;
		Dist.z = static_cast<double>(m_World->GetTickRandomNumber(10)) - 5.0;

		if ((Dist.SqrLength() > 2)  && (rem >= 3))
		{

			Vector3d Destination(GetPosX() + Dist.x, GetPosition().y, GetPosZ() + Dist.z);

			cChunk * Chunk = a_Chunk.GetNeighborChunk(static_cast<int>(Destination.x), static_cast<int>(Destination.z));
			if ((Chunk == nullptr) || !Chunk->IsValid())
			{
				return;
			}

			BLOCKTYPE BlockType;
			NIBBLETYPE BlockMeta;
			int RelX = static_cast<int>(Destination.x) - Chunk->GetPosX() * cChunkDef::Width;
			int RelZ = static_cast<int>(Destination.z) - Chunk->GetPosZ() * cChunkDef::Width;
			int YBelowUs = static_cast<int>(Destination.y) - 1;
			if (YBelowUs >= 0)
			{
				Chunk->GetBlockTypeMeta(RelX, YBelowUs, RelZ, BlockType, BlockMeta);
				if (BlockType != E_BLOCK_STATIONARY_WATER)  // Idle mobs shouldn't enter water on purpose
				{
					MoveToPosition(Destination);
				}
			}
		}
	}
}
コード例 #2
0
ファイル: Monster.cpp プロジェクト: 4264/cuberite
bool cMonster::WouldBurnAt(Vector3d a_Location, cChunk & a_Chunk)
{
	cChunk * Chunk = a_Chunk.GetNeighborChunk(FloorC(a_Location.x), FloorC(a_Location.z));
	if ((Chunk == nullptr) || (!Chunk->IsValid()))
	{
		return false;
	}

	int RelX = FloorC(a_Location.x) - Chunk->GetPosX() * cChunkDef::Width;
	int RelY = FloorC(a_Location.y);
	int RelZ = FloorC(a_Location.z) - Chunk->GetPosZ() * cChunkDef::Width;

	if (
		(Chunk->GetSkyLight(RelX, RelY, RelZ) == 15) &&             // In the daylight
		(Chunk->GetBlock(RelX, RelY, RelZ) != E_BLOCK_SOULSAND) &&  // Not on soulsand
		(GetWorld()->GetTimeOfDay() < (12000 + 1000)) &&             // It is nighttime
		GetWorld()->IsWeatherSunnyAt(POSX_TOINT, POSZ_TOINT)         // Not raining
	)
	{
		return true;
	}
	return false;
}
コード例 #3
0
ファイル: Monster.cpp プロジェクト: 4264/cuberite
bool cMonster::EnsureProperDestination(cChunk & a_Chunk)
{
	cChunk * Chunk = a_Chunk.GetNeighborChunk(FloorC(m_FinalDestination.x), FloorC(m_FinalDestination.z));
	BLOCKTYPE BlockType;
	NIBBLETYPE BlockMeta;

	if ((Chunk == nullptr) || !Chunk->IsValid())
	{
		return false;
	}

	int RelX = FloorC(m_FinalDestination.x) - Chunk->GetPosX() * cChunkDef::Width;
	int RelZ = FloorC(m_FinalDestination.z) - Chunk->GetPosZ() * cChunkDef::Width;

	// If destination in the air, first try to go 1 block north, or east, or west.
	// This fixes the player leaning issue.
	// If that failed, we instead go down to the lowest air block.
	Chunk->GetBlockTypeMeta(RelX, FloorC(m_FinalDestination.y) - 1, RelZ, BlockType, BlockMeta);
	if (!cBlockInfo::IsSolid(BlockType))
	{
		bool InTheAir = true;
		int x, z;
		for (z = -1; z <= 1; ++z)
		{
			for (x = -1; x <= 1; ++x)
			{
				if ((x==0) && (z==0))
				{
					continue;
				}
				Chunk = a_Chunk.GetNeighborChunk(FloorC(m_FinalDestination.x+x), FloorC(m_FinalDestination.z+z));
				if ((Chunk == nullptr) || !Chunk->IsValid())
				{
					return false;
				}
				RelX = FloorC(m_FinalDestination.x+x) - Chunk->GetPosX() * cChunkDef::Width;
				RelZ = FloorC(m_FinalDestination.z+z) - Chunk->GetPosZ() * cChunkDef::Width;
				Chunk->GetBlockTypeMeta(RelX, FloorC(m_FinalDestination.y) - 1, RelZ, BlockType, BlockMeta);
				if (cBlockInfo::IsSolid(BlockType))
				{
					m_FinalDestination.x += x;
					m_FinalDestination.z += z;
					InTheAir = false;
					goto breakBothLoops;
				}
			}
		}
		breakBothLoops:

		// Go down to the lowest air block.
		if (InTheAir)
		{
			while (m_FinalDestination.y > 0)
			{
				Chunk->GetBlockTypeMeta(RelX, FloorC(m_FinalDestination.y) - 1, RelZ, BlockType, BlockMeta);
				if (cBlockInfo::IsSolid(BlockType))
				{
					break;
				}
				m_FinalDestination.y -= 1;
			}
		}
	}

	// If destination in water, go up to the highest water block.
	// If destination in solid, go up to first air block.
	bool InWater = false;
	while (m_FinalDestination.y < cChunkDef::Height)
	{
		Chunk->GetBlockTypeMeta(RelX, FloorC(m_FinalDestination.y), RelZ, BlockType, BlockMeta);
		if (BlockType == E_BLOCK_STATIONARY_WATER)
		{
			InWater = true;
		}
		else if (cBlockInfo::IsSolid(BlockType))
		{
			InWater = false;
		}
		else
		{
			break;
		}
		m_FinalDestination.y += 1;
	}
	if (InWater)
	{
		m_FinalDestination.y -= 1;
	}


	return true;
}
コード例 #4
0
ファイル: Pickup.cpp プロジェクト: crexalbo/MCServer
void cPickup::Tick(float a_Dt, cChunk & a_Chunk)
{
	super::Tick(a_Dt, a_Chunk);
	BroadcastMovementUpdate(); //Notify clients of position

	m_Timer += a_Dt;
	
	if (!m_bCollected)
	{
		int BlockY = (int) floor(GetPosY());
		if ((BlockY >= 0) && (BlockY < cChunkDef::Height))  // Don't do anything except for falling when outside the world
		{
			int BlockX = (int) floor(GetPosX());
			int BlockZ = (int) floor(GetPosZ());
			// Position might have changed due to physics. So we have to make sure we have the correct chunk.
			cChunk * CurrentChunk = a_Chunk.GetNeighborChunk(BlockX, BlockZ);
			if (CurrentChunk != NULL)  // Make sure the chunk is loaded
			{
				int RelBlockX = BlockX - (CurrentChunk->GetPosX() * cChunkDef::Width);
				int RelBlockZ = BlockZ - (CurrentChunk->GetPosZ() * cChunkDef::Width);
				
				// If the pickup is on the bottommost block position, make it think the void is made of air: (#131)
				BLOCKTYPE BlockBelow = (BlockY > 0) ? CurrentChunk->GetBlock(RelBlockX, BlockY - 1, RelBlockZ) : E_BLOCK_AIR;
				BLOCKTYPE BlockIn = CurrentChunk->GetBlock(RelBlockX, BlockY, RelBlockZ);

				if (
					IsBlockLava(BlockBelow) || (BlockBelow == E_BLOCK_FIRE) ||
					IsBlockLava(BlockIn) || (BlockIn == E_BLOCK_FIRE)
				)
				{
					m_bCollected = true;
					m_Timer = 0;  // We have to reset the timer.
					m_Timer += a_Dt;  // In case we have to destroy the pickup in the same tick.
					if (m_Timer > 500.f)  
					{
						Destroy(true);
						return;
					}
				}

				if (!IsDestroyed()) // Don't try to combine if someone has tried to combine me
				{
					cPickupCombiningCallback PickupCombiningCallback(GetPosition(), this);
					m_World->ForEachEntity(PickupCombiningCallback); // Not ForEachEntityInChunk, otherwise pickups don't combine across chunk boundaries
					if (PickupCombiningCallback.FoundMatchingPickup())
					{
						m_World->BroadcastEntityMetadata(*this);
					}
				}
			}
		}
	}
	else
	{
		if (m_Timer > 500.f)  // 0.5 second
		{
			Destroy(true);
			return;
		}
	}

	if (m_Timer > 1000 * 60 * 5)  // 5 minutes
	{
		Destroy(true);
		return;
	}

	if (GetPosY() < -8) // Out of this world and no more visible!
	{
		Destroy(true);
		return;
	}
}
コード例 #5
0
ファイル: Pickup.cpp プロジェクト: ravenscroftj/MCServer
void cPickup::Tick(float a_Dt, cChunk & a_Chunk)
{
	super::Tick(a_Dt, a_Chunk);
	BroadcastMovementUpdate(); //Notify clients of position

	m_Timer += a_Dt;
	
	if (!m_bCollected)
	{
		int BlockY = (int) floor(GetPosY());
		if (BlockY < cChunkDef::Height)  // Don't do anything except for falling when above the world
		{
			int BlockX = (int) floor(GetPosX());
			int BlockZ = (int) floor(GetPosZ());
			//Position might have changed due to physics. So we have to make sure we have the correct chunk.
			cChunk * CurrentChunk = a_Chunk.GetNeighborChunk(BlockX, BlockZ);
			if (CurrentChunk != NULL)  // Make sure the chunk is loaded
			{
				int RelBlockX = BlockX - (CurrentChunk->GetPosX() * cChunkDef::Width);
				int RelBlockZ = BlockZ - (CurrentChunk->GetPosZ() * cChunkDef::Width);
				
				BLOCKTYPE BlockBelow = CurrentChunk->GetBlock(RelBlockX, BlockY - 1, RelBlockZ);
				BLOCKTYPE BlockIn = CurrentChunk->GetBlock(RelBlockX, BlockY, RelBlockZ);

				if (
					IsBlockLava(BlockBelow) || (BlockBelow == E_BLOCK_FIRE) ||
					IsBlockLava(BlockIn) || (BlockIn == E_BLOCK_FIRE)
				)
				{
					m_bCollected = true;
					m_Timer = 0;  // We have to reset the timer.
					m_Timer += a_Dt;  // In case we have to destroy the pickup in the same tick.
					if (m_Timer > 500.f)  
					{
						Destroy(true);
						return;
					}
				}
			}
		}
	}
	else
	{
		if (m_Timer > 500.f)  // 0.5 second
		{
			Destroy(true);
			return;
		}
	}

	if (m_Timer > 1000 * 60 * 5)  // 5 minutes
	{
		Destroy(true);
		return;
	}

	if (GetPosY() < -8) // Out of this world and no more visible!
	{
		Destroy(true);
		return;
	}
}
コード例 #6
0
ファイル: PathFinder.cpp プロジェクト: AddictXQ/cuberite
bool cPathFinder::EnsureProperPoint(Vector3d & a_Vector, cChunk & a_Chunk)
{
	cChunk * Chunk = a_Chunk.GetNeighborChunk(FloorC(a_Vector.x), FloorC(a_Vector.z));
	BLOCKTYPE BlockType;
	NIBBLETYPE BlockMeta;

	if ((Chunk == nullptr) || !Chunk->IsValid())
	{
		return false;
	}

	int RelX = FloorC(a_Vector.x) - Chunk->GetPosX() * cChunkDef::Width;
	int RelZ = FloorC(a_Vector.z) - Chunk->GetPosZ() * cChunkDef::Width;

	// If destination in the air, first try to go 1 block north, or east, or west.
	// This fixes the player leaning issue.
	// If that failed, we instead go down to the lowest air block.
	Chunk->GetBlockTypeMeta(RelX, FloorC(a_Vector.y) - 1, RelZ, BlockType, BlockMeta);
	if (!(IsWaterOrSolid(BlockType)))
	{
		bool InTheAir = true;
		int x, z;
		for (z = -1; z <= 1; ++z)
		{
			for (x = -1; x <= 1; ++x)
			{
				if ((x == 0) && (z == 0))
				{
					continue;
				}
				Chunk = a_Chunk.GetNeighborChunk(FloorC(a_Vector.x+x), FloorC(a_Vector.z+z));
				if ((Chunk == nullptr) || !Chunk->IsValid())
				{
					return false;
				}
				RelX = FloorC(a_Vector.x+x) - Chunk->GetPosX() * cChunkDef::Width;
				RelZ = FloorC(a_Vector.z+z) - Chunk->GetPosZ() * cChunkDef::Width;
				Chunk->GetBlockTypeMeta(RelX, FloorC(a_Vector.y) - 1, RelZ, BlockType, BlockMeta);
				if (IsWaterOrSolid((BlockType)))
				{
					a_Vector.x += x;
					a_Vector.z += z;
					InTheAir = false;
					goto breakBothLoops;
				}
			}
		}
		breakBothLoops:

		// Go down to the lowest air block.
		if (InTheAir)
		{
			while (a_Vector.y > 0)
			{
				Chunk->GetBlockTypeMeta(RelX, FloorC(a_Vector.y) - 1, RelZ, BlockType, BlockMeta);
				if (IsWaterOrSolid(BlockType))
				{
					break;
				}
				a_Vector.y -= 1;
			}
		}
	}

	// If destination in water or solid, go up to the first air block.
	while (a_Vector.y < cChunkDef::Height)
	{
		Chunk->GetBlockTypeMeta(RelX, FloorC(a_Vector.y), RelZ, BlockType, BlockMeta);
		if (!IsWaterOrSolid(BlockType))
		{
			break;
		}
		a_Vector.y += 1;
	}

	return true;
}
コード例 #7
0
ファイル: Entity.cpp プロジェクト: ravenscroftj/MCServer
void cEntity::HandlePhysics(float a_Dt, cChunk & a_Chunk)
{
	// TODO Add collision detection with entities.
	a_Dt /= 1000;
	Vector3d NextPos = Vector3d(GetPosX(),GetPosY(),GetPosZ());
	Vector3d NextSpeed = Vector3d(GetSpeedX(),GetSpeedY(),GetSpeedZ());
	int BlockX = (int) floor(NextPos.x);
	int BlockY = (int) floor(NextPos.y);
	int BlockZ = (int) floor(NextPos.z);
	
	if ((BlockY >= cChunkDef::Height) || (BlockY < 0))
	{
		// Outside of the world
		// TODO: Current speed should still be added to the entity position
		// Otherwise TNT explosions in the void will still effect the bottommost layers of the world
		return;
	}
	
	// Make sure we got the correct chunk and a valid one. No one ever knows...
	cChunk * NextChunk = a_Chunk.GetNeighborChunk(BlockX,BlockZ);
	if (NextChunk != NULL)
	{
		int RelBlockX = BlockX - (NextChunk->GetPosX() * cChunkDef::Width);
		int RelBlockZ = BlockZ - (NextChunk->GetPosZ() * cChunkDef::Width);
		BLOCKTYPE BlockIn = NextChunk->GetBlock( RelBlockX, BlockY, RelBlockZ );
		if (!g_BlockIsSolid[BlockIn])  // Making sure we are not inside a solid block
		{
			if (m_bOnGround)  // check if it's still on the ground
			{
				BLOCKTYPE BlockBelow = NextChunk->GetBlock( RelBlockX, BlockY - 1, RelBlockZ );
				if (!g_BlockIsSolid[BlockBelow])  // Check if block below is air or water.
				{
					m_bOnGround = false;
				}
			}
		}
		else
		{
			//Push out entity.
			m_bOnGround = true;
			NextPos.y += 0.2;
			LOGD("Entity #%d (%s) is inside a block at {%d,%d,%d}",
				m_UniqueID, GetClass(), BlockX, BlockY, BlockZ);
		}

		if (!m_bOnGround)
		{
			float fallspeed;
			if (IsBlockWater(BlockIn))
			{
				fallspeed = -3.0f * a_Dt; //Fall slower in water.
			}
			else if (BlockIn == E_BLOCK_COBWEB)
			{
				NextSpeed.y *= 0.05; //Reduce overall falling speed
				fallspeed = 0; //No falling.
			}
			else
			{
				//Normal gravity
				fallspeed = m_Gravity * a_Dt;
			}
			NextSpeed.y += fallspeed;
		}
		else
		{
			//Friction
			if (NextSpeed.SqrLength() > 0.0004f)
			{
				NextSpeed.x *= 0.7f/(1+a_Dt);
				if ( fabs(NextSpeed.x) < 0.05 ) NextSpeed.x = 0;
				NextSpeed.z *= 0.7f/(1+a_Dt);
				if ( fabs(NextSpeed.z) < 0.05 ) NextSpeed.z = 0;
			}
		}

		//Adjust X and Z speed for COBWEB temporary. This speed modification should be handled inside block handlers since we
		//might have different speed modifiers according to terrain.
		if (BlockIn == E_BLOCK_COBWEB)
		{
			NextSpeed.x *= 0.25;
			NextSpeed.z *= 0.25;
		}
					
		//Get water direction
		Direction WaterDir = m_World->GetWaterSimulator()->GetFlowingDirection(BlockX, BlockY, BlockZ);

		m_WaterSpeed *= 0.9f;		//Reduce speed each tick

		switch(WaterDir)
		{
			case X_PLUS:
				m_WaterSpeed.x = 1.f;
				m_bOnGround = false;
				break;
			case X_MINUS:
				m_WaterSpeed.x = -1.f;
				m_bOnGround = false;
				break;
			case Z_PLUS:
				m_WaterSpeed.z = 1.f;
				m_bOnGround = false;
				break;
			case Z_MINUS:
				m_WaterSpeed.z = -1.f;
				m_bOnGround = false;
				break;
			
		default:
			break;
		}

		if (fabs(m_WaterSpeed.x) < 0.05)
		{
			m_WaterSpeed.x = 0;
		}

		if (fabs(m_WaterSpeed.z) < 0.05)
		{
			m_WaterSpeed.z = 0;
		}

		NextSpeed += m_WaterSpeed;

		if( NextSpeed.SqrLength() > 0.f )
		{
			cTracer Tracer( GetWorld() );
			int Ret = Tracer.Trace( NextPos, NextSpeed, 2 );
			if( Ret ) // Oh noez! we hit something
			{
				// Set to hit position
				if( (Tracer.RealHit - NextPos).SqrLength() <= ( NextSpeed * a_Dt ).SqrLength() )
				{
					if( Ret == 1 )
					{

						if( Tracer.HitNormal.x != 0.f ) NextSpeed.x = 0.f;
						if( Tracer.HitNormal.y != 0.f ) NextSpeed.y = 0.f;
						if( Tracer.HitNormal.z != 0.f ) NextSpeed.z = 0.f;

						if( Tracer.HitNormal.y > 0 ) // means on ground
						{
							m_bOnGround = true;
						}
					}
					NextPos.Set(Tracer.RealHit.x,Tracer.RealHit.y,Tracer.RealHit.z);
					NextPos.x += Tracer.HitNormal.x * 0.5f;
					NextPos.z += Tracer.HitNormal.z * 0.5f;
				}
				else
					NextPos += (NextSpeed * a_Dt);
			}
			else
			{
				// We didn't hit anything, so move =]
				NextPos += (NextSpeed * a_Dt);
			}
		}
		BlockX = (int) floor(NextPos.x);
		BlockZ = (int) floor(NextPos.z);
		NextChunk = NextChunk->GetNeighborChunk(BlockX,BlockZ);
		// See if we can commit our changes. If not, we will discard them.
		if (NextChunk != NULL)
		{
			if (NextPos.x != GetPosX()) SetPosX(NextPos.x);
			if (NextPos.y != GetPosY()) SetPosY(NextPos.y);
			if (NextPos.z != GetPosZ()) SetPosZ(NextPos.z);
			if (NextSpeed.x != GetSpeedX()) SetSpeedX(NextSpeed.x);
			if (NextSpeed.y != GetSpeedY()) SetSpeedY(NextSpeed.y);
			if (NextSpeed.z != GetSpeedZ()) SetSpeedZ(NextSpeed.z);
		}
	}
}
コード例 #8
0
ファイル: Entity.cpp プロジェクト: straemer/MCServer
void cEntity::HandlePhysics(float a_Dt, cChunk & a_Chunk)
{
	// TODO Add collision detection with entities.
	a_Dt /= 1000;  // Convert from msec to sec
	Vector3d NextPos = Vector3d(GetPosX(),GetPosY(),GetPosZ());
	Vector3d NextSpeed = Vector3d(GetSpeedX(),GetSpeedY(),GetSpeedZ());
	int BlockX = (int) floor(NextPos.x);
	int BlockY = (int) floor(NextPos.y);
	int BlockZ = (int) floor(NextPos.z);
	
	if ((BlockY >= cChunkDef::Height) || (BlockY < 0))
	{
		// Outside of the world

		cChunk * NextChunk = a_Chunk.GetNeighborChunk(BlockX, BlockZ);
		// See if we can commit our changes. If not, we will discard them.
		if (NextChunk != NULL)
		{
			SetSpeed(NextSpeed);
			NextPos += (NextSpeed * a_Dt);
			SetPosition(NextPos);
		}
		return;
	}
	
	// Make sure we got the correct chunk and a valid one. No one ever knows...
	cChunk * NextChunk = a_Chunk.GetNeighborChunk(BlockX, BlockZ);
	if (NextChunk != NULL)
	{
		int RelBlockX = BlockX - (NextChunk->GetPosX() * cChunkDef::Width);
		int RelBlockZ = BlockZ - (NextChunk->GetPosZ() * cChunkDef::Width);
		BLOCKTYPE BlockIn = NextChunk->GetBlock( RelBlockX, BlockY, RelBlockZ );
		BLOCKTYPE BlockBelow = (BlockY > 0) ? NextChunk->GetBlock(RelBlockX, BlockY - 1, RelBlockZ) : E_BLOCK_AIR;
		if (!g_BlockIsSolid[BlockIn])  // Making sure we are not inside a solid block
		{
			if (m_bOnGround)  // check if it's still on the ground
			{
				if (!g_BlockIsSolid[BlockBelow])  // Check if block below is air or water.
				{
					m_bOnGround = false;
				}
			}
		}
		else
		{
			// Push out entity.
			BLOCKTYPE GotBlock;

			static const struct
			{
				int x, y, z;
			} gCrossCoords[] =
			{
				{ 1, 0,  0},
				{-1, 0,  0},
				{ 0, 0,  1},
				{ 0, 0, -1},
			} ;

			bool IsNoAirSurrounding = true;
			for (int i = 0; i < ARRAYCOUNT(gCrossCoords); i++)
			{
				if (!NextChunk->UnboundedRelGetBlockType(RelBlockX + gCrossCoords[i].x, BlockY, RelBlockZ + gCrossCoords[i].z, GotBlock))
				{
					// The pickup is too close to an unloaded chunk, bail out of any physics handling
					return;
				}
				if (!g_BlockIsSolid[GotBlock])
				{
					NextPos.x += gCrossCoords[i].x;
					NextPos.z += gCrossCoords[i].z;
					IsNoAirSurrounding = false;
					break;
				}
			}  // for i - gCrossCoords[]
			
			if (IsNoAirSurrounding)
			{
				NextPos.y += 0.5;
			}

			m_bOnGround = true;

			LOGD("Entity #%d (%s) is inside a block at {%d, %d, %d}",
				m_UniqueID, GetClass(), BlockX, BlockY, BlockZ
			);
		}

		if (!m_bOnGround)
		{
			float fallspeed;
			if (IsBlockWater(BlockIn))
			{
				fallspeed = m_Gravity * a_Dt / 3;  // Fall 3x slower in water.
			}
			else if (IsBlockRail(BlockBelow) && IsMinecart())  // Rails aren't solid, except for Minecarts
			{
				fallspeed = 0;
				m_bOnGround = true;
			}
			else if (BlockIn == E_BLOCK_COBWEB)
			{
				NextSpeed.y *= 0.05;  // Reduce overall falling speed
				fallspeed = 0;  // No falling.
			}
			else
			{
				// Normal gravity
				fallspeed = m_Gravity * a_Dt;
			}
			NextSpeed.y += fallspeed;
		}
		else
		{
			if (IsMinecart())
			{
				if (!IsBlockRail(BlockBelow))
				{
					// Friction if minecart is off track, otherwise, Minecart.cpp handles this
					if (NextSpeed.SqrLength() > 0.0004f)
					{
						NextSpeed.x *= 0.7f / (1 + a_Dt);
						if (fabs(NextSpeed.x) < 0.05)
						{
							NextSpeed.x = 0;
						}
						NextSpeed.z *= 0.7f / (1 + a_Dt);
						if (fabs(NextSpeed.z) < 0.05)
						{
							NextSpeed.z = 0;
						}
					}
				}
			}
			else
			{
				// Friction for non-minecarts
				if (NextSpeed.SqrLength() > 0.0004f)
				{
					NextSpeed.x *= 0.7f / (1 + a_Dt);
					if (fabs(NextSpeed.x) < 0.05)
					{
						NextSpeed.x = 0;
					}
					NextSpeed.z *= 0.7f / (1 + a_Dt);
					if (fabs(NextSpeed.z) < 0.05)
					{
						NextSpeed.z = 0;
					}
				}
			}
		}

		// Adjust X and Z speed for COBWEB temporary. This speed modification should be handled inside block handlers since we
		// might have different speed modifiers according to terrain.
		if (BlockIn == E_BLOCK_COBWEB)
		{
			NextSpeed.x *= 0.25;
			NextSpeed.z *= 0.25;
		}
					
		//Get water direction
		Direction WaterDir = m_World->GetWaterSimulator()->GetFlowingDirection(BlockX, BlockY, BlockZ);

		m_WaterSpeed *= 0.9f;		//Reduce speed each tick

		switch(WaterDir)
		{
			case X_PLUS:
				m_WaterSpeed.x = 0.2f;
				m_bOnGround = false;
				break;
			case X_MINUS:
				m_WaterSpeed.x = -0.2f;
				m_bOnGround = false;
				break;
			case Z_PLUS:
				m_WaterSpeed.z = 0.2f;
				m_bOnGround = false;
				break;
			case Z_MINUS:
				m_WaterSpeed.z = -0.2f;
				m_bOnGround = false;
				break;
			
		default:
			break;
		}

		if (fabs(m_WaterSpeed.x) < 0.05)
		{
			m_WaterSpeed.x = 0;
		}

		if (fabs(m_WaterSpeed.z) < 0.05)
		{
			m_WaterSpeed.z = 0;
		}

		NextSpeed += m_WaterSpeed;

		if( NextSpeed.SqrLength() > 0.f )
		{
			cTracer Tracer( GetWorld() );
			int Ret = Tracer.Trace( NextPos, NextSpeed, 2 );
			if( Ret ) // Oh noez! we hit something
			{
				// Set to hit position
				if( (Tracer.RealHit - NextPos).SqrLength() <= ( NextSpeed * a_Dt ).SqrLength() )
				{
					if( Ret == 1 )
					{
						if( Tracer.HitNormal.x != 0.f ) NextSpeed.x = 0.f;
						if( Tracer.HitNormal.y != 0.f ) NextSpeed.y = 0.f;
						if( Tracer.HitNormal.z != 0.f ) NextSpeed.z = 0.f;

						if( Tracer.HitNormal.y > 0 ) // means on ground
						{
							m_bOnGround = true;
						}
					}
					NextPos.Set(Tracer.RealHit.x,Tracer.RealHit.y,Tracer.RealHit.z);
					NextPos.x += Tracer.HitNormal.x * 0.3f;
					NextPos.y += Tracer.HitNormal.y * 0.05f; // Any larger produces entity vibration-upon-the-spot
					NextPos.z += Tracer.HitNormal.z * 0.3f;
				}
				else
				{
					NextPos += (NextSpeed * a_Dt);
				}
			}
			else
			{
				// We didn't hit anything, so move =]
				NextPos += (NextSpeed * a_Dt);
			}
		}
		BlockX = (int) floor(NextPos.x);
		BlockZ = (int) floor(NextPos.z);
		NextChunk = NextChunk->GetNeighborChunk(BlockX,BlockZ);
		// See if we can commit our changes. If not, we will discard them.
		if (NextChunk != NULL)
		{
			if (NextPos.x != GetPosX()) SetPosX(NextPos.x);
			if (NextPos.y != GetPosY()) SetPosY(NextPos.y);
			if (NextPos.z != GetPosZ()) SetPosZ(NextPos.z);
			if (NextSpeed.x != GetSpeedX()) SetSpeedX(NextSpeed.x);
			if (NextSpeed.y != GetSpeedY()) SetSpeedY(NextSpeed.y);
			if (NextSpeed.z != GetSpeedZ()) SetSpeedZ(NextSpeed.z);
		}
	}
}