Exemplo n.º 1
0
void Rotation::getValue(Vector3d & axis, double & rfAngle) const
{
    // Taken from <http://de.wikipedia.org/wiki/Quaternionen>
    //
    // Note: -1 < w < +1 (|w| == 1 not allowed, with w:=quat[3]) 
    if((this->quat[3] > -1.0) && (this->quat[3] < 1.0)) {
        rfAngle = double(acos(this->quat[3])) * 2.0;
        double scale = (double)sin(rfAngle / 2.0);
        // Get a normalized vector 
        axis.x = this->quat[0] / scale;
        axis.y = this->quat[1] / scale;
        axis.z = this->quat[2] / scale;
    }
    else {
        // The quaternion doesn't describe a rotation, so we can setup any value we want 
        axis.Set(0.0, 0.0, 1.0);
        rfAngle = 0.0;
    }
}
Exemplo n.º 2
0
void ScannerConfigSingle::CreateDefault()
{
	m_brightnessthreshold = 128;
	SetLaserPosition(200,0,0); // 200 mm to the left of the camera
	m_assumelaservertical = false;
	
	m_usecanny = false;
	m_canny_threshold1 = 10;
	m_canny_threshold2 = 100;
	m_canny_apertureSize = 3;

	point_3d lookat;
	Vector3d up;

	m_reference.Set(0,-1,0,300);
	m_camera.global_view.Initialize();		
	m_camera.viewing_distance = 500;
	lookat.Set(0,100,0); // look down the world y axis
	up.Set(0,0,1);
	m_camera.LookAt(&lookat,&up);
	m_camera.global_view.Rotate(.5,.5,0); // need to make this askew because of a matix pivot / inverse issue
	/*
		In this alg, the wall is at the walldist away, and the camera
		is considered to be 0,0,0 origin.
		------------------------------ +X (reference plane)
		|				|
		|				V
		|
		|
		|
		|				^
		|				|
		-Y			(camera)
					 origin (0,0,0)
	*/

}
Exemplo n.º 3
0
void Chunk::Init() {
	int width = g_BoxWidth;
	int depth = g_BoxDepth;
	int height = g_BoxHeight;

	int nCount = 0;

	float xLimit = 0;
	float yLimit = 0;
	float zLimit = 0;
	
	CPerformanceCounter counter;
	counter.Start();

	m_ChunkPrim.Init();

	m_pPhysContainer = new PhysContainer;
	m_GameObjects = new GameObject[g_BoxWidth * g_BoxDepth * g_BoxHeight];
	m_pBoxGrid = NULL;//new Prim_t*[g_BoxWidth * g_BoxDepth * g_BoxHeight];

	//m_pPhysContainer->halfwidths.Set(width * 4.0f + 0.01f, height * 4.0f + 0.01f, depth * 4.0f + 0.01f);
	//m_pPhysContainer->center.Set( );
	
	Vector3d transPos;
	transPos.Set( m_Pos );//-128.0f, -10.0f, -128.0f);

	for ( int h = 0; h < height; ++h ){
		for ( int i = 0; i < depth; ++i ){
			for ( int j = 0; j < width; ++j ){
				int idx = (h*(depth*width)) + (i*width) + j;
				//printf("idx: %d\n", idx);
				
				int r = rand() % 100;
				
				if( r > 65 ) {
					float x = transPos.x + (j*8);
					float y = transPos.y + (h*8);
					float z = transPos.z + (i*8);
					
					float xFabs = fabs(x);
					float yFabs = fabs(y);
					float zFabs = fabs(z);
					
					if( xFabs > xLimit) xLimit = xFabs;
					if( yFabs > yLimit) yLimit = yFabs;
					if( zFabs > zLimit) zLimit = zFabs;

					/*
					if( r > 75) {
						m_pBoxGrid[ idx ] = CreateBox( "dirt.raw", 4 );
					} else {
						m_pBoxGrid[ idx ] = CreateBox( "test.raw", 4 );
					}
					*/
					//m_pBoxGrid[ idx ] = CreateBox( "test.raw", 4 );
					
					//m_pBoxGrid[ idx ]->vPos.Set( x, y, z );
					m_GameObjects[ idx ].renderable = NULL;
					
					Vector3d boxPos;
					boxPos.Set( transPos.x * -1.0f, transPos.y * -1.0f, transPos.z * -1.0f );
					boxPos.x += x;
					boxPos.y += y;
					boxPos.z += z;
					#if CHUNK_OPTIMIZATIONS
					m_ChunkPrim.AddBoxOpt(boxPos);
					#else
					m_ChunkPrim.AddBox(boxPos);
					#endif
					
					//if(m_pBoxGrid[ idx ] == NULL) {
						//printf("Box call failed\n");
					//}
					
					//printf("Box Pos: %f %f %f\n", g_pBoxGrid[ idx ]->vPos.x, g_pBoxGrid[ idx ]->vPos.y, g_pBoxGrid[ idx ]->vPos.z);
		
					//m_GameObjects[ idx ].renderable = m_pBoxGrid[ idx ];
					m_GameObjects[ idx ].phys = new PhysObject;
		
					//center point
					m_GameObjects[ idx ].phys->center.Set(transPos.x + (j*8), (transPos.y *0.5f) + (h*8), transPos.z + (i*8));
					m_GameObjects[ idx ].phys->halfwidths.Set(4.0f,4.0f,4.0f);

					m_pPhysContainer->AddObject( m_GameObjects[ idx ].phys );
					
					nCount++;
				} else {
					m_GameObjects[ idx ].renderable = NULL;
					m_GameObjects[ idx ].phys = NULL;
					//printf("renderable set to NULL\n");
				}
	
			}
		}
	}

	m_pPhysContainer->halfwidths.Set(width * 4.0f + 0.01f, height * 4.0f + 0.01f, depth * 4.0f + 0.01f);
	m_pPhysContainer->center.Set( transPos.x + ((width-1)*4.0f) , (height * 4.0f) + transPos.y, transPos.z + ((depth-1.0f)*4.0f));
	PhysicsManager::GetInstance().AddContainer( m_pPhysContainer );

	//m_pPhysContainer->SetDebug( true );
	//Vector3d boxPos;
	//m_ChunkPrim.AddBox(boxPos);
	
	#if CHUNK_OPTIMIZATIONS
	m_ChunkPrim.AddFaces();
	#endif
	m_ChunkPrim.Bake();
	m_ChunkPrim.m_Prim.vPos.Set( transPos );

	//printf("%d boxes created\n", nCount);
	
	//m_ChunkPrim.PrintFaces();
	counter.Stop();
	
	printf("Chunk generated in %f seconds.\n", counter.TimeInMilliseconds());
}
Exemplo n.º 4
0
void cEntity::HandlePhysics(float a_Dt, cChunk & a_Chunk)
{
	int BlockX = POSX_TOINT;
	int BlockY = POSY_TOINT;
	int BlockZ = POSZ_TOINT;

	// Position changed -> super::HandlePhysics() called
	GET_AND_VERIFY_CURRENT_CHUNK(NextChunk, BlockX, BlockZ)

	// 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());
	
	if ((BlockY >= cChunkDef::Height) || (BlockY < 0))
	{
		// Outside of the world		
		AddSpeedY(m_Gravity * a_Dt);
		AddPosition(GetSpeed() * a_Dt);
		return;
	}
	
	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 (!cBlockInfo::IsSolid(BlockIn))  // Making sure we are not inside a solid block
	{
		if (m_bOnGround)  // check if it's still on the ground
		{
			if (!cBlockInfo::IsSolid(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 (size_t 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 (!cBlockInfo::IsSolid(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;

		/*
		// DEBUG:
		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 (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 = 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());
		// Distance traced is an integer, so we round up from the distance we should go (Speed * Delta), else we will encounter collision detection failurse
		int DistanceToTrace = (int)(ceil((NextSpeed * a_Dt).SqrLength()) * 2);
		bool HasHit = Tracer.Trace(NextPos, NextSpeed, DistanceToTrace);

		if (HasHit)
		{
			// Oh noez! We hit something: verify that the (hit position - current) was smaller or equal to the (position that we should travel without obstacles - current)
			// This is because previously, we traced with a length that was rounded up (due to integer limitations), and in the case that something was hit, we don't want to overshoot our projected movement
			if ((Tracer.RealHit - NextPos).SqrLength() <= (NextSpeed * a_Dt).SqrLength())
			{
				// Block hit was within our projected path
				// Begin by stopping movement in the direction that we hit something. The Normal is the line perpendicular to a 2D face and in this case, stores what block face was hit through either -1 or 1.
				// For example: HitNormal.y = -1 : BLOCK_FACE_YM; HitNormal.y = 1 : BLOCK_FACE_YP
				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 == 1) // Hit BLOCK_FACE_YP, we are on the ground
				{
					m_bOnGround = true;
				}

				// Now, set our position to the hit block (i.e. move part way along our intended trajectory)
				NextPos.Set(Tracer.RealHit.x, Tracer.RealHit.y, Tracer.RealHit.z);
				NextPos.x += Tracer.HitNormal.x * 0.1;
				NextPos.y += Tracer.HitNormal.y * 0.05;
				NextPos.z += Tracer.HitNormal.z * 0.1;
			}
			else
			{
				// We have hit a block but overshot our intended trajectory, move normally, safe in the warm cocoon of knowledge that we won't appear to teleport forwards on clients,
				// and that this piece of software will come to be hailed as the epitome of performance and functionality in C++, never before seen, and of such a like that will never
				// be henceforth seen again in the time of programmers and man alike
				// </&sensationalist>
				NextPos += (NextSpeed * a_Dt);
			}
		}
		else
		{
			// We didn't hit anything, so move =]
			NextPos += (NextSpeed * a_Dt);
		}
	}

	SetPosition(NextPos);
	SetSpeed(NextSpeed);
}
Exemplo n.º 5
0
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);
		}
	}
}
Exemplo n.º 6
0
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);
		}
	}
}