hl2sdk/game/server/nav_area.cpp

//========= Copyright <20> 1996-2005, Valve Corporation, All rights reserved. ============//
//
// Purpose: 
//
// $NoKeywords: $
//
//=============================================================================//
// nav_area.cpp
// AI Navigation areas
// Author: Michael S. Booth (mike@turtlerockstudios.com), January 2003

#include "cbase.h"

#include "nav_mesh.h"
#include "nav_node.h"
#include "nav_pathfind.h"
#include "nav_colors.h"
#include "fmtstr.h"
#include "props_shared.h"
#include "func_breakablesurf.h"
#include "Color.h"
#include "collisionutils.h"

// memdbgon must be the last include file in a .cpp file!!!
#include <tier0/memdbgon.h>

#ifdef _WIN32
#pragma warning (disable:4701)				// disable warning that variable *may* not be initialized 
#endif

extern void HintMessageToAllPlayers( const char *message );

unsigned int CNavArea::m_nextID = 1;
NavAreaList TheNavAreaList;

unsigned int CNavArea::m_masterMarker = 1;
CNavArea *CNavArea::m_openList = NULL;

bool CNavArea::m_isReset = false;

ConVar nav_coplanar_slope_limit( "nav_coplanar_slope_limit", "0.99", FCVAR_GAMEDLL );
ConVar nav_split_place_on_ground( "nav_split_place_on_ground", "0", FCVAR_GAMEDLL, "If true, nav areas will be placed flush with the ground when split." );
ConVar nav_area_bgcolor( "nav_area_bgcolor", "0 0 0 30", FCVAR_GAMEDLL, "RGBA color to draw as the background color for nav areas while editing." );
ConVar nav_corner_adjust_adjacent( "nav_corner_adjust_adjacent", "18", FCVAR_GAMEDLL, "radius used to raise/lower corners in nearby areas when raising/lowering corners." );

//--------------------------------------------------------------------------------------------------------------
void CNavArea::CompressIDs( void )
{
	m_nextID = 1;

	FOR_EACH_LL( TheNavAreaList, id )
	{
		CNavArea *area = TheNavAreaList[id];
		area->m_id = m_nextID++;

		// remove and re-add the area from the nav mesh to update the hashed ID
		TheNavMesh->RemoveNavArea( area );
		TheNavMesh->AddNavArea( area );
	}
}


//--------------------------------------------------------------------------------------------------------------
/**
 * To keep constructors consistent
 */
void CNavArea::Initialize( void )
{
	m_marker = 0;
	m_parent = NULL;
	m_parentHow = GO_NORTH;
	m_attributeFlags = 0;
	m_place = TheNavMesh->GetNavPlace();
	m_isBlocked = false;
	m_isUnderwater = false;

	ResetNodes();

	int i;
	for ( i=0; i<MAX_NAV_TEAMS; ++i )
	{
		m_danger[i] = 0.0f;
		m_dangerTimestamp[i] = 0.0f;

		m_clearedTimestamp[i] = 0.0f;

		m_earliestOccupyTime[i] = 0.0f;
	
		m_playerCount[i] = 0;
	}

	m_approachCount = 0;

	// set an ID for splitting and other interactive editing - loads will overwrite this
	m_id = m_nextID++;

	m_prevHash = NULL;
	m_nextHash = NULL;

	m_isBattlefront = false;

	for( i = 0; i<NUM_DIRECTIONS; ++i )
	{
		m_connect[i].RemoveAll();
	}

	for( i=0; i<CNavLadder::NUM_LADDER_DIRECTIONS; ++i )
	{
		m_ladder[i].RemoveAll();
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Constructor used during normal runtime.
 */
CNavArea::CNavArea( void )
{
	Initialize();
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Assumes Z is flat
 */
CNavArea::CNavArea( const Vector &corner, const Vector &otherCorner )
{
	Initialize();

	if (corner.x < otherCorner.x)
	{
		m_extent.lo.x = corner.x;
		m_extent.hi.x = otherCorner.x;
	}
	else
	{
		m_extent.hi.x = corner.x;
		m_extent.lo.x = otherCorner.x;
	}

	if (corner.y < otherCorner.y)
	{
		m_extent.lo.y = corner.y;
		m_extent.hi.y = otherCorner.y;
	}
	else
	{
		m_extent.hi.y = corner.y;
		m_extent.lo.y = otherCorner.y;
	}

	m_extent.lo.z = corner.z;
	m_extent.hi.z = corner.z;

	m_center.x = (m_extent.lo.x + m_extent.hi.x)/2.0f;
	m_center.y = (m_extent.lo.y + m_extent.hi.y)/2.0f;
	m_center.z = (m_extent.lo.z + m_extent.hi.z)/2.0f;

	m_neZ = corner.z;
	m_swZ = otherCorner.z;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * 
 */
CNavArea::CNavArea( const Vector &nwCorner, const Vector &neCorner, const Vector &seCorner, const Vector &swCorner )
{
	Initialize();

	m_extent.lo = nwCorner;
	m_extent.hi = seCorner;

	m_center.x = (m_extent.lo.x + m_extent.hi.x)/2.0f;
	m_center.y = (m_extent.lo.y + m_extent.hi.y)/2.0f;
	m_center.z = (m_extent.lo.z + m_extent.hi.z)/2.0f;

	m_neZ = neCorner.z;
	m_swZ = swCorner.z;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Constructor used during generation phase.
 */
CNavArea::CNavArea( CNavNode *nwNode, CNavNode *neNode, CNavNode *seNode, CNavNode *swNode )
{
	Initialize();

	m_extent.lo = *nwNode->GetPosition();
	m_extent.hi = *seNode->GetPosition();

	m_center.x = (m_extent.lo.x + m_extent.hi.x)/2.0f;
	m_center.y = (m_extent.lo.y + m_extent.hi.y)/2.0f;
	m_center.z = (m_extent.lo.z + m_extent.hi.z)/2.0f;

	m_neZ = neNode->GetPosition()->z;
	m_swZ = swNode->GetPosition()->z;

	m_node[ NORTH_WEST ] = nwNode;
	m_node[ NORTH_EAST ] = neNode;
	m_node[ SOUTH_EAST ] = seNode;
	m_node[ SOUTH_WEST ] = swNode;

	// mark internal nodes as part of this area
	AssignNodes( this );
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Destructor
 */
CNavArea::~CNavArea()
{
	m_spotEncounterList.PurgeAndDeleteElements();

	// if we are resetting the system, don't bother cleaning up - all areas are being destroyed
	if (m_isReset)
		return;

	// tell the other areas we are going away
	FOR_EACH_LL( TheNavAreaList, it )
	{
		CNavArea *area = TheNavAreaList[ it ];

		if (area == this)
			continue;

		area->OnDestroyNotify( this );
	}

	// unhook from ladders
	{
		FOR_EACH_LL( TheNavMesh->GetLadders(), it )
		{
			CNavLadder *ladder = TheNavMesh->GetLadders()[ it ];

			ladder->OnDestroyNotify( this );
		}
	}

	// remove the area from the grid
	TheNavMesh->RemoveNavArea( this );
}


//--------------------------------------------------------------------------------------------------------------
/**
 * This is invoked at the start of an incremental nav generation on pre-existing areas.
 */
void CNavArea::ResetNodes( void )
{
	for ( int i=0; i<NUM_CORNERS; ++i )
	{
		m_node[i] = NULL;
	}
}


//--------------------------------------------------------------------------------------------------------------
bool CNavArea::HasNodes( void ) const
{
	for ( int i=0; i<NUM_CORNERS; ++i )
	{
		if ( m_node[i] )
		{
			return true;
		}
	}

	return false;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * This is invoked when an area is going away.
 * Remove any references we have to it.
 */
void CNavArea::OnDestroyNotify( CNavArea *dead )
{
	NavConnect con;
	con.area = dead;
	for( int d=0; d<NUM_DIRECTIONS; ++d )
		m_connect[ d ].FindAndRemove( con );

	m_overlapList.FindAndRemove( dead );
}


//--------------------------------------------------------------------------------------------------------------
/**
 * This is invoked when a ladder is going away.
 * Remove any references we have to it.
 */
void CNavArea::OnDestroyNotify( CNavLadder *dead )
{
	Disconnect( dead );
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Connect this area to given area in given direction
 */
void CNavArea::ConnectTo( CNavArea *area, NavDirType dir )
{
	// don't allow self-referential connections
	if ( area == this )
		return;

	// check if already connected
	FOR_EACH_LL( m_connect[ dir ], it )
	{
		if (m_connect[ dir ][ it ].area == area)
			return;
	}

	NavConnect con;
	con.area = area;
	m_connect[ dir ].AddToTail( con );

	//static char *dirName[] = { "NORTH", "EAST", "SOUTH", "WEST" };
	//CONSOLE_ECHO( "  Connected area #%d to #%d, %s\n", m_id, area->m_id, dirName[ dir ] );
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Connect this area to given ladder
 */
void CNavArea::ConnectTo( CNavLadder *ladder )
{
	float center = (ladder->m_top.z + ladder->m_bottom.z) * 0.5f;

	Disconnect( ladder ); // just in case

	if ( GetCenter().z > center )
	{
		AddLadderDown( ladder );
	}
	else
	{
		AddLadderUp( ladder );
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Disconnect this area from given area
 */
void CNavArea::Disconnect( CNavArea *area )
{
	NavConnect connect;
	connect.area = area;

	for( int dir = 0; dir<NUM_DIRECTIONS; dir++ )
	{
		m_connect[ dir ].FindAndRemove( connect );
	}
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Disconnect this area from given ladder
 */
void CNavArea::Disconnect( CNavLadder *ladder )
{
	NavLadderConnect con;
	con.ladder = ladder;

	for( int i=0; i<CNavLadder::NUM_LADDER_DIRECTIONS; ++i )
	{
		m_ladder[i].FindAndRemove( con );
	}
}


//--------------------------------------------------------------------------------------------------------------
void CNavArea::AddLadderUp( CNavLadder *ladder )
{
	Disconnect( ladder ); // just in case

	NavLadderConnect tmp;
	tmp.ladder = ladder;
	m_ladder[ CNavLadder::LADDER_UP ].AddToTail( tmp );
}


//--------------------------------------------------------------------------------------------------------------
void CNavArea::AddLadderDown( CNavLadder *ladder )
{
	Disconnect( ladder ); // just in case

	NavLadderConnect tmp;
	tmp.ladder = ladder;
	m_ladder[ CNavLadder::LADDER_DOWN ].AddToTail( tmp );
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Recompute internal data once nodes have been adjusted during merge
 * Destroy adjArea.
 */
void CNavArea::FinishMerge( CNavArea *adjArea )
{
	// update extent
	m_extent.lo = *m_node[ NORTH_WEST ]->GetPosition();
	m_extent.hi = *m_node[ SOUTH_EAST ]->GetPosition();

	m_center.x = (m_extent.lo.x + m_extent.hi.x)/2.0f;
	m_center.y = (m_extent.lo.y + m_extent.hi.y)/2.0f;
	m_center.z = (m_extent.lo.z + m_extent.hi.z)/2.0f;

	m_neZ = m_node[ NORTH_EAST ]->GetPosition()->z;
	m_swZ = m_node[ SOUTH_WEST ]->GetPosition()->z;

	// reassign the adjacent area's internal nodes to the final area
	adjArea->AssignNodes( this );

	// merge adjacency links - we gain all the connections that adjArea had
	MergeAdjacentConnections( adjArea );

	// remove subsumed adjacent area
	TheNavAreaList.FindAndRemove( adjArea );
	delete adjArea;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * For merging with "adjArea" - pick up all of "adjArea"s connections
 */
void CNavArea::MergeAdjacentConnections( CNavArea *adjArea )
{
	// merge adjacency links - we gain all the connections that adjArea had
	int dir;
	for( dir = 0; dir<NUM_DIRECTIONS; dir++ )
	{
		FOR_EACH_LL( adjArea->m_connect[ dir ], it )
		{
			NavConnect connect = adjArea->m_connect[ dir ][ it ];

			if (connect.area != adjArea && connect.area != this)
				ConnectTo( connect.area, (NavDirType)dir );
		}
	}

	// remove any references from this area to the adjacent area, since it is now part of us
	for( dir = 0; dir<NUM_DIRECTIONS; dir++ )
	{
		NavConnect connect;
		connect.area = adjArea;

		m_connect[dir].FindAndRemove( connect );
	}

	// Change other references to adjArea to refer instead to us
	// We can't just replace existing connections, as several adjacent areas may have been merged into one,
	// resulting in a large area adjacent to all of them ending up with multiple redunandant connections
	// into the merged area, one for each of the adjacent subsumed smaller ones.
	// If an area has a connection to the merged area, we must remove all references to adjArea, and add
	// a single connection to us.
	FOR_EACH_LL( TheNavAreaList, it )
	{
		CNavArea *area = TheNavAreaList[ it ];

		if (area == this || area == adjArea)
			continue;

		for( dir = 0; dir<NUM_DIRECTIONS; dir++ )
		{
			// check if there are any references to adjArea in this direction
			bool connected = false;
			FOR_EACH_LL( area->m_connect[ dir ], cit )
			{
				NavConnect connect = area->m_connect[ dir ][ cit ];

				if (connect.area == adjArea)
				{
					connected = true;
					break;
				}
			}

			if (connected)
			{
				// remove all references to adjArea
				NavConnect connect;
				connect.area = adjArea;
				area->m_connect[dir].FindAndRemove( connect );

				// remove all references to the new area
				connect.area = this;
				area->m_connect[dir].FindAndRemove( connect );

				// add a single connection to the new area
				connect.area = this;
				area->m_connect[dir].AddToTail( connect );
			}
		}
	}

	// We gain all ladder connections adjArea had
	for( dir=0; dir<CNavLadder::NUM_LADDER_DIRECTIONS; ++dir )
	{
		FOR_EACH_LL( adjArea->m_ladder[ dir ], it )
		{
			ConnectTo( adjArea->m_ladder[ dir ][ it ].ladder );
		}
	}

	// All ladders that point to adjArea should point to us now
	FOR_EACH_LL( TheNavMesh->GetLadders(), lit )
	{
		CNavLadder *ladder = TheNavMesh->GetLadders()[lit];

		if ( ladder->m_topForwardArea == adjArea )
			ladder->m_topForwardArea = this;

		if ( ladder->m_topRightArea == adjArea )
			ladder->m_topRightArea = this;

		if ( ladder->m_topLeftArea == adjArea )
			ladder->m_topLeftArea = this;

		if ( ladder->m_topBehindArea == adjArea )
			ladder->m_topBehindArea = this;

		if ( ladder->m_bottomArea == adjArea )
			ladder->m_bottomArea = this;
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Assign internal nodes to the given area
 * NOTE: "internal" nodes do not include the east or south border nodes
 */
void CNavArea::AssignNodes( CNavArea *area )
{
	CNavNode *horizLast = m_node[ NORTH_EAST ];

	for( CNavNode *vertNode = m_node[ NORTH_WEST ]; vertNode != m_node[ SOUTH_WEST ]; vertNode = vertNode->GetConnectedNode( SOUTH ) )
	{
		for( CNavNode *horizNode = vertNode; horizNode != horizLast; horizNode = horizNode->GetConnectedNode( EAST ) )
		{
			horizNode->AssignArea( area );
		}

		horizLast = horizLast->GetConnectedNode( SOUTH );
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Split this area into two areas at the given edge.
 * Preserve all adjacency connections.
 * NOTE: This does not update node connections, only areas.
 */
bool CNavArea::SplitEdit( bool splitAlongX, float splitEdge, CNavArea **outAlpha, CNavArea **outBeta )
{
	CNavArea *alpha = NULL;
	CNavArea *beta = NULL;

	if (splitAlongX)
	{
		// +-----+->X
		// |  A  |
		// +-----+
		// |  B  |
		// +-----+
		// |
		// Y

		// don't do split if at edge of area
		if (splitEdge <= m_extent.lo.y + 1.0f)
			return false;

		if (splitEdge >= m_extent.hi.y - 1.0f)
			return false;

		alpha = new CNavArea;
		alpha->m_extent.lo = m_extent.lo;

		alpha->m_extent.hi.x = m_extent.hi.x;
		alpha->m_extent.hi.y = splitEdge;
		alpha->m_extent.hi.z = GetZ( alpha->m_extent.hi );

		beta = new CNavArea;
		beta->m_extent.lo.x = m_extent.lo.x;
		beta->m_extent.lo.y = splitEdge;
		beta->m_extent.lo.z = GetZ( beta->m_extent.lo );

		beta->m_extent.hi = m_extent.hi;

		alpha->ConnectTo( beta, SOUTH );
		beta->ConnectTo( alpha, NORTH );

		FinishSplitEdit( alpha, SOUTH );
		FinishSplitEdit( beta, NORTH );
	}
	else
	{
		// +--+--+->X
		// |  |  |
		// | A|B |
		// |  |  |
		// +--+--+
		// |
		// Y

		// don't do split if at edge of area
		if (splitEdge <= m_extent.lo.x + 1.0f)
			return false;

		if (splitEdge >= m_extent.hi.x - 1.0f)
			return false;

		alpha = new CNavArea;
		alpha->m_extent.lo = m_extent.lo;

		alpha->m_extent.hi.x = splitEdge;
		alpha->m_extent.hi.y = m_extent.hi.y;
		alpha->m_extent.hi.z = GetZ( alpha->m_extent.hi );

		beta = new CNavArea;
		beta->m_extent.lo.x = splitEdge;
		beta->m_extent.lo.y = m_extent.lo.y;
		beta->m_extent.lo.z = GetZ( beta->m_extent.lo );

		beta->m_extent.hi = m_extent.hi;

		alpha->ConnectTo( beta, EAST );
		beta->ConnectTo( alpha, WEST );

		FinishSplitEdit( alpha, EAST );
		FinishSplitEdit( beta, WEST );
	}

	if ( !TheNavMesh->IsGenerating() && nav_split_place_on_ground.GetBool() )
	{
		alpha->PlaceOnGround( NUM_CORNERS );
		beta->PlaceOnGround( NUM_CORNERS );
	}

	// For every ladder we pointed to, alpha or beta should point to it, based on
	// their distance to the ladder
	int dir;
	for( dir=0; dir<CNavLadder::NUM_LADDER_DIRECTIONS; ++dir )
	{
		FOR_EACH_LL( m_ladder[ dir ], it )
		{
			CNavLadder *ladder = m_ladder[ dir ][ it ].ladder;
			Vector ladderPos = ladder->m_top; // doesn't matter if we choose top or bottom

			float alphaDistance = alpha->GetDistanceSquaredToPoint( ladderPos );
			float betaDistance = beta->GetDistanceSquaredToPoint( ladderPos );

			if ( alphaDistance < betaDistance )
			{
				alpha->ConnectTo( ladder );
			}
			else
			{
				beta->ConnectTo( ladder );
			}
		}
	}

	// For every ladder that pointed to us, connect that ladder to the closer of alpha and beta
	FOR_EACH_LL( TheNavMesh->GetLadders(), lit )
	{
		CNavLadder *ladder = TheNavMesh->GetLadders()[lit];
		ladder->OnSplit( this, alpha, beta );
	}

	// new areas inherit attributes from original area
	alpha->SetAttributes( GetAttributes() );
	beta->SetAttributes( GetAttributes() );

	// new areas inherit place from original area
	alpha->SetPlace( GetPlace() );
	beta->SetPlace( GetPlace() );

	// return new areas
	if (outAlpha)
		*outAlpha = alpha;

	if (outBeta)
		*outBeta = beta;

	// remove original area
	TheNavAreaList.FindAndRemove( this );
	delete this;

	return true;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if given ladder is connected in given direction
 * @todo Formalize "asymmetric" flag on connections
 */
bool CNavArea::IsConnected( const CNavLadder *ladder, CNavLadder::LadderDirectionType dir ) const
{
	FOR_EACH_LL( m_ladder[ dir ], it )
	{
		if ( ladder == m_ladder[ dir ][ it ].ladder )
		{
			return true;
		}
	}

	return false;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if given area is connected in given direction
 * if dir == NUM_DIRECTIONS, check all directions (direction is unknown)
 * @todo Formalize "asymmetric" flag on connections
 */
bool CNavArea::IsConnected( const CNavArea *area, NavDirType dir ) const
{
	// we are connected to ourself
	if (area == this)
		return true;

	if (dir == NUM_DIRECTIONS)
	{
		// search all directions
		for( int d=0; d<NUM_DIRECTIONS; ++d )
		{
			FOR_EACH_LL( m_connect[ d ], it )
			{
				if (area == m_connect[ d ][ it ].area)
					return true;
			}
		}

		// check ladder connections
		FOR_EACH_LL( m_ladder[ CNavLadder::LADDER_UP ], it )
		{
			CNavLadder *ladder = m_ladder[ CNavLadder::LADDER_UP ][ it ].ladder;

			if (ladder->m_topBehindArea == area ||
				ladder->m_topForwardArea == area ||
				ladder->m_topLeftArea == area ||
				ladder->m_topRightArea == area)
				return true;
		}

		FOR_EACH_LL( m_ladder[ CNavLadder::LADDER_DOWN ], dit )
		{
			CNavLadder *ladder = m_ladder[ CNavLadder::LADDER_DOWN ][ dit ].ladder;

			if (ladder->m_bottomArea == area)
				return true;
		}
	}
	else
	{
		// check specific direction
		FOR_EACH_LL( m_connect[ dir ], it )
		{
			if (area == m_connect[ dir ][ it ].area)
				return true;
		}
	}

	return false;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Compute change in height from this area to given area
 * @todo This is approximate for now
 */
float CNavArea::ComputeHeightChange( const CNavArea *area )
{
	float ourZ = GetZ( GetCenter() );
	float areaZ = area->GetZ( area->GetCenter() );

	return areaZ - ourZ;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Given the portion of the original area, update its internal data
 * The "ignoreEdge" direction defines the side of the original area that the new area does not include
 */
void CNavArea::FinishSplitEdit( CNavArea *newArea, NavDirType ignoreEdge )
{
	newArea->m_center.x = (newArea->m_extent.lo.x + newArea->m_extent.hi.x)/2.0f;
	newArea->m_center.y = (newArea->m_extent.lo.y + newArea->m_extent.hi.y)/2.0f;
	newArea->m_center.z = (newArea->m_extent.lo.z + newArea->m_extent.hi.z)/2.0f;

	newArea->m_neZ = GetZ( newArea->m_extent.hi.x, newArea->m_extent.lo.y );
	newArea->m_swZ = GetZ( newArea->m_extent.lo.x, newArea->m_extent.hi.y );

	// connect to adjacent areas
	for( int d=0; d<NUM_DIRECTIONS; ++d )
	{
		if (d == ignoreEdge)
			continue;

		int count = GetAdjacentCount( (NavDirType)d );

		for( int a=0; a<count; ++a )
		{
			CNavArea *adj = GetAdjacentArea( (NavDirType)d, a );

			switch( d )
			{
				case NORTH:
				case SOUTH:
					if (newArea->IsOverlappingX( adj ))
					{
						newArea->ConnectTo( adj, (NavDirType)d );			

						// add reciprocal connection if needed
						if (adj->IsConnected( this, OppositeDirection( (NavDirType)d )))
							adj->ConnectTo( newArea, OppositeDirection( (NavDirType)d ) );
					}
					break;

				case EAST:
				case WEST:
					if (newArea->IsOverlappingY( adj ))
					{
						newArea->ConnectTo( adj, (NavDirType)d );			

						// add reciprocal connection if needed
						if (adj->IsConnected( this, OppositeDirection( (NavDirType)d )))
							adj->ConnectTo( newArea, OppositeDirection( (NavDirType)d ) );
					}
					break;
			}
		}
	}

	TheNavAreaList.AddToTail( newArea );
	TheNavMesh->AddNavArea( newArea );

	// Assign nodes
	if ( HasNodes() )
	{
		// first give it all our nodes...
		newArea->m_node[ NORTH_WEST ] = m_node[ NORTH_WEST ];
		newArea->m_node[ NORTH_EAST ] = m_node[ NORTH_EAST ];
		newArea->m_node[ SOUTH_EAST ] = m_node[ SOUTH_EAST ];
		newArea->m_node[ SOUTH_WEST ] = m_node[ SOUTH_WEST ];

		// ... then pull in one edge...
		NavDirType dir = NUM_DIRECTIONS;
		NavCornerType corner[2] = { NUM_CORNERS, NUM_CORNERS };

		switch ( ignoreEdge )
		{
		case NORTH:
			dir = SOUTH;
			corner[0] = NORTH_WEST;
			corner[1] = NORTH_EAST;
			break;
		case SOUTH:
			dir = NORTH;
			corner[0] = SOUTH_WEST;
			corner[1] = SOUTH_EAST;
			break;
		case EAST:
			dir = WEST;
			corner[0] = NORTH_EAST;
			corner[1] = SOUTH_EAST;
			break;
		case WEST:
			dir = EAST;
			corner[0] = NORTH_WEST;
			corner[1] = SOUTH_WEST;
			break;
		default:
			break;
		}

		while ( !newArea->IsOverlapping( *newArea->m_node[ corner[0] ]->GetPosition(), GenerationStepSize/2 ) )
		{
			for ( int i=0; i<2; ++i )
			{
				Assert( newArea->m_node[ corner[i] ] );
				Assert( newArea->m_node[ corner[i] ]->GetConnectedNode( dir ) );
				newArea->m_node[ corner[i] ] = newArea->m_node[ corner[i] ]->GetConnectedNode( dir );
			}
		}

		// assign internal nodes...
		newArea->AssignNodes( newArea );

		// ... and grab the node heights for our corner heights.
		newArea->m_neZ			= newArea->m_node[ NORTH_EAST ]->GetPosition()->z;
		newArea->m_extent.lo.z	= newArea->m_node[ NORTH_WEST ]->GetPosition()->z;
		newArea->m_swZ			= newArea->m_node[ SOUTH_WEST ]->GetPosition()->z;
		newArea->m_extent.hi.z	= newArea->m_node[ SOUTH_EAST ]->GetPosition()->z;
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Create a new area between this area and given area 
 */
bool CNavArea::SpliceEdit( CNavArea *other )
{
	CNavArea *newArea = NULL;
	Vector nw, ne, se, sw;

	if (m_extent.lo.x > other->m_extent.hi.x)
	{
		// 'this' is east of 'other'
		float top = MAX( m_extent.lo.y, other->m_extent.lo.y );
		float bottom = MIN( m_extent.hi.y, other->m_extent.hi.y );

		nw.x = other->m_extent.hi.x;
		nw.y = top;
		nw.z = other->GetZ( nw );

		se.x = m_extent.lo.x;
		se.y = bottom;
		se.z = GetZ( se );

		ne.x = se.x;
		ne.y = nw.y;
		ne.z = GetZ( ne );

		sw.x = nw.x;
		sw.y = se.y;
		sw.z = other->GetZ( sw );

		newArea = new CNavArea( nw, ne, se, sw );

		this->ConnectTo( newArea, WEST );
		newArea->ConnectTo( this, EAST );

		other->ConnectTo( newArea, EAST );
		newArea->ConnectTo( other, WEST );
	}
	else if (m_extent.hi.x < other->m_extent.lo.x)
	{
		// 'this' is west of 'other'
		float top = MAX( m_extent.lo.y, other->m_extent.lo.y );
		float bottom = MIN( m_extent.hi.y, other->m_extent.hi.y );

		nw.x = m_extent.hi.x;
		nw.y = top;
		nw.z = GetZ( nw );

		se.x = other->m_extent.lo.x;
		se.y = bottom;
		se.z = other->GetZ( se );

		ne.x = se.x;
		ne.y = nw.y;
		ne.z = other->GetZ( ne );

		sw.x = nw.x;
		sw.y = se.y;
		sw.z = GetZ( sw );

		newArea = new CNavArea( nw, ne, se, sw );

		this->ConnectTo( newArea, EAST );
		newArea->ConnectTo( this, WEST );

		other->ConnectTo( newArea, WEST );
		newArea->ConnectTo( other, EAST );
	}
	else	// 'this' overlaps in X
	{
		if (m_extent.lo.y > other->m_extent.hi.y)
		{
			// 'this' is south of 'other'
			float left = MAX( m_extent.lo.x, other->m_extent.lo.x );
			float right = MIN( m_extent.hi.x, other->m_extent.hi.x );

			nw.x = left;
			nw.y = other->m_extent.hi.y;
			nw.z = other->GetZ( nw );

			se.x = right;
			se.y = m_extent.lo.y;
			se.z = GetZ( se );

			ne.x = se.x;
			ne.y = nw.y;
			ne.z = other->GetZ( ne );

			sw.x = nw.x;
			sw.y = se.y;
			sw.z = GetZ( sw );

			newArea = new CNavArea( nw, ne, se, sw );

			this->ConnectTo( newArea, NORTH );
			newArea->ConnectTo( this, SOUTH );

			other->ConnectTo( newArea, SOUTH );
			newArea->ConnectTo( other, NORTH );
		}
		else if (m_extent.hi.y < other->m_extent.lo.y)
		{
			// 'this' is north of 'other'
			float left = MAX( m_extent.lo.x, other->m_extent.lo.x );
			float right = MIN( m_extent.hi.x, other->m_extent.hi.x );

			nw.x = left;
			nw.y = m_extent.hi.y;
			nw.z = GetZ( nw );

			se.x = right;
			se.y = other->m_extent.lo.y;
			se.z = other->GetZ( se );

			ne.x = se.x;
			ne.y = nw.y;
			ne.z = GetZ( ne );

			sw.x = nw.x;
			sw.y = se.y;
			sw.z = other->GetZ( sw );

			newArea = new CNavArea( nw, ne, se, sw );

			this->ConnectTo( newArea, SOUTH );
			newArea->ConnectTo( this, NORTH );

			other->ConnectTo( newArea, NORTH );
			newArea->ConnectTo( other, SOUTH );
		}
		else
		{
			// areas overlap
			return false;
		}
	}

	// if both areas have the same place, the new area inherits it
	if (GetPlace() == other->GetPlace())
	{
		newArea->SetPlace( GetPlace() );
	}
	else if (GetPlace() == UNDEFINED_PLACE)
	{
		newArea->SetPlace( other->GetPlace() );
	}
	else if (other->GetPlace() == UNDEFINED_PLACE)
	{
		newArea->SetPlace( GetPlace() );
	}
	else
	{
		// both have valid, but different places - pick on at random
		if (RandomInt( 0, 100 ) < 50)
			newArea->SetPlace( GetPlace() );
		else
			newArea->SetPlace( other->GetPlace() );
	}

	TheNavAreaList.AddToTail( newArea );
	TheNavMesh->AddNavArea( newArea );

	return true;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Merge this area and given adjacent area 
 */
bool CNavArea::MergeEdit( CNavArea *adj )
{
	// can only merge if attributes of both areas match


	// check that these areas can be merged
	const float tolerance = 1.0f;
	bool merge = false;
	if (fabs( m_extent.lo.x - adj->m_extent.lo.x ) < tolerance && 
		fabs( m_extent.hi.x - adj->m_extent.hi.x ) < tolerance)
		merge = true;

	if (fabs( m_extent.lo.y - adj->m_extent.lo.y ) < tolerance && 
		fabs( m_extent.hi.y - adj->m_extent.hi.y ) < tolerance)
		merge = true;

	if (merge == false)
		return false;

	Extent origExtent = m_extent;
	
	// update extent
	if (m_extent.lo.x > adj->m_extent.lo.x || m_extent.lo.y > adj->m_extent.lo.y)
		m_extent.lo = adj->m_extent.lo;

	if (m_extent.hi.x < adj->m_extent.hi.x || m_extent.hi.y < adj->m_extent.hi.y)
		m_extent.hi = adj->m_extent.hi;

	m_center.x = (m_extent.lo.x + m_extent.hi.x)/2.0f;
	m_center.y = (m_extent.lo.y + m_extent.hi.y)/2.0f;
	m_center.z = (m_extent.lo.z + m_extent.hi.z)/2.0f;

	if (m_extent.hi.x > origExtent.hi.x || m_extent.lo.y < origExtent.lo.y)
		m_neZ = adj->GetZ( m_extent.hi.x, m_extent.lo.y );
	else
		m_neZ = GetZ( m_extent.hi.x, m_extent.lo.y );

	if (m_extent.lo.x < origExtent.lo.x || m_extent.hi.y > origExtent.hi.y)
		m_swZ = adj->GetZ( m_extent.lo.x, m_extent.hi.y );
	else
		m_swZ = GetZ( m_extent.lo.x, m_extent.hi.y );

	// merge adjacency links - we gain all the connections that adjArea had
	MergeAdjacentConnections( adj );

	// remove subsumed adjacent area
	TheNavAreaList.FindAndRemove( adj );
	delete adj;

	return true;
}

//--------------------------------------------------------------------------------------------------------------
void ApproachAreaAnalysisPrep( void )
{
}

//--------------------------------------------------------------------------------------------------------------
void CleanupApproachAreaAnalysisPrep( void )
{
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Remove "analyzed" data from nav area
 */
void CNavArea::Strip( void )
{
	m_approachCount = 0;
	m_spotEncounterList.PurgeAndDeleteElements(); // this calls delete on each element
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if area is more or less square.
 * This is used when merging to prevent long, thin, areas being created.
 */
bool CNavArea::IsRoughlySquare( void ) const
{
	float aspect = GetSizeX() / GetSizeY();

	const float maxAspect = 3.01;
	const float minAspect = 1.0f / maxAspect;
	if (aspect < minAspect || aspect > maxAspect)
		return false;

	return true;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if 'pos' is within 2D extents of area.
 */
bool CNavArea::IsOverlapping( const Vector &pos, float tolerance ) const
{
	if (pos.x + tolerance >= m_extent.lo.x && pos.x - tolerance <= m_extent.hi.x &&
		pos.y + tolerance >= m_extent.lo.y && pos.y - tolerance <= m_extent.hi.y)
		return true;

	return false;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if 'area' overlaps our 2D extents
 */
bool CNavArea::IsOverlapping( const CNavArea *area ) const
{
	if (area->m_extent.lo.x < m_extent.hi.x && area->m_extent.hi.x > m_extent.lo.x && 
		area->m_extent.lo.y < m_extent.hi.y && area->m_extent.hi.y > m_extent.lo.y)
		return true;

	return false;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if 'area' overlaps our X extent
 */
bool CNavArea::IsOverlappingX( const CNavArea *area ) const
{
	if (area->m_extent.lo.x < m_extent.hi.x && area->m_extent.hi.x > m_extent.lo.x)
		return true;

	return false;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if 'area' overlaps our Y extent
 */
bool CNavArea::IsOverlappingY( const CNavArea *area ) const
{
	if (area->m_extent.lo.y < m_extent.hi.y && area->m_extent.hi.y > m_extent.lo.y)
		return true;

	return false;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if given point is on or above this area, but no others
 */
bool CNavArea::Contains( const Vector &pos ) const
{
	// check 2D overlap
	if (!IsOverlapping( pos ))
		return false;

	// the point overlaps us, check that it is above us, but not above any areas that overlap us
	float myZ = GetZ( pos );

	// if the nav area is above the given position, fail
	if (myZ > pos.z)
		return false;

	FOR_EACH_LL( m_overlapList, it )
	{
		const CNavArea *area = m_overlapList[ it ];

		// skip self
		if (area == this)
			continue;

		// check 2D overlap
		if (!area->IsOverlapping( pos ))
			continue;

		float theirZ = area->GetZ( pos );
		if (theirZ > pos.z)
		{
			// they are above the point
			continue;
		}

		if (theirZ > myZ)
		{
			// we are below an area that is beneath the given position
			return false;
		}
	}

	return true;
}


//--------------------------------------------------------------------------------------------------------------
void CNavArea::ComputeNormal( Vector *normal, bool alternate ) const
{
	if ( !normal )
		return;

	Vector u, v;

	if ( !alternate )
	{
		u.x = m_extent.hi.x - m_extent.lo.x;
		u.y = 0.0f;
		u.z = m_neZ - m_extent.lo.z;

		v.x = 0.0f;
		v.y = m_extent.hi.y - m_extent.lo.y;
		v.z = m_swZ - m_extent.lo.z;
	}
	else
	{
		u.x = m_extent.lo.x - m_extent.hi.x;
		u.y = 0.0f;
		u.z = m_swZ - m_extent.hi.z;

		v.x = 0.0f;
		v.y = m_extent.lo.y - m_extent.hi.y;
		v.z = m_neZ - m_extent.hi.z;
	}

	*normal = CrossProduct( u, v );
	normal->NormalizeInPlace();
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if the area is approximately flat, using normals computed from opposite corners
 */
bool CNavArea::IsFlat( void ) const
{
	Vector normal, otherNormal;
	ComputeNormal( &normal );
	ComputeNormal( &otherNormal, true );

	const float tolerance = nav_coplanar_slope_limit.GetFloat();
	if (DotProduct( normal, otherNormal ) > tolerance)
		return true;

	return false;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if this area and given area are approximately co-planar
 */
bool CNavArea::IsCoplanar( const CNavArea *area ) const
{
	Vector u, v;

	if ( !IsFlat() )
		return false;

	if ( !area->IsFlat() )
		return false;

	// compute our unit surface normal
	Vector normal, otherNormal;
	ComputeNormal( &normal );
	area->ComputeNormal( &otherNormal );

	// can only merge areas that are nearly planar, to ensure areas do not differ from underlying geometry much
	const float tolerance = nav_coplanar_slope_limit.GetFloat(); //0.99f; // 0.7071f;		// 0.9
	if (DotProduct( normal, otherNormal ) > tolerance)
		return true;

	return false;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return Z of area at (x,y) of 'pos'
 * Trilinear interpolation of Z values at quad edges.
 * NOTE: pos->z is not used.
 */
float CNavArea::GetZ( const Vector &pos ) const
{
	float dx = m_extent.hi.x - m_extent.lo.x;
	float dy = m_extent.hi.y - m_extent.lo.y;

	// guard against division by zero due to degenerate areas
	if (dx == 0.0f || dy == 0.0f)
		return m_neZ;

	float u = (pos.x - m_extent.lo.x) / dx;
	float v = (pos.y - m_extent.lo.y) / dy;

	// clamp Z values to (x,y) volume
	if (u < 0.0f)
		u = 0.0f;
	else if (u > 1.0f)
		u = 1.0f;
		
	if (v < 0.0f)
		v = 0.0f;
	else if (v > 1.0f)
		v = 1.0f;

	float northZ = m_extent.lo.z + u * (m_neZ - m_extent.lo.z);
	float southZ = m_swZ + u * (m_extent.hi.z - m_swZ);
	
	return northZ + v * (southZ - northZ);
}

float CNavArea::GetZ( float x, float y ) const
{
	Vector pos( x, y, 0.0f );
	return GetZ( pos );
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Return closest point to 'pos' on 'area'.
 * Returned point is in 'close'.
 */
void CNavArea::GetClosestPointOnArea( const Vector &pos, Vector *close ) const
{
	const Extent &extent = GetExtent();

	if (pos.x < extent.lo.x)
	{
		if (pos.y < extent.lo.y)
		{
			// position is north-west of area
			*close = extent.lo;
		}
		else if (pos.y > extent.hi.y)
		{
			// position is south-west of area
			close->x = extent.lo.x;
			close->y = extent.hi.y;
		}
		else
		{
			// position is west of area
			close->x = extent.lo.x;
			close->y = pos.y;
		}
	}
	else if (pos.x > extent.hi.x)
	{
		if (pos.y < extent.lo.y)
		{
			// position is north-east of area
			close->x = extent.hi.x;
			close->y = extent.lo.y;
		}
		else if (pos.y > extent.hi.y)
		{
			// position is south-east of area
			*close = extent.hi;
		}
		else
		{
			// position is east of area
			close->x = extent.hi.x;
			close->y = pos.y;
		}
	}
	else if (pos.y < extent.lo.y)
	{
		// position is north of area
		close->x = pos.x;
		close->y = extent.lo.y;
	}
	else if (pos.y > extent.hi.y)
	{
		// position is south of area
		close->x = pos.x;
		close->y = extent.hi.y;
	}
	else
	{
		// position is inside of area - it is the 'closest point' to itself
		*close = pos;
	}

	close->z = GetZ( *close );
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return shortest distance squared between point and this area
 */
float CNavArea::GetDistanceSquaredToPoint( const Vector &pos ) const
{
	const Extent &extent = GetExtent();

	if (pos.x < extent.lo.x)
	{
		if (pos.y < extent.lo.y)
		{
			// position is north-west of area
			return (extent.lo - pos).LengthSqr();
		}
		else if (pos.y > extent.hi.y)
		{
			// position is south-west of area
			Vector d;
			d.x = extent.lo.x - pos.x;
			d.y = extent.hi.y - pos.y;
			d.z = m_swZ - pos.z;
			return d.LengthSqr();
		}
		else
		{
			// position is west of area
			float d = extent.lo.x - pos.x;
			return d * d;
		}
	}
	else if (pos.x > extent.hi.x)
	{
		if (pos.y < extent.lo.y)
		{
			// position is north-east of area
			Vector d;
			d.x = extent.hi.x - pos.x;
			d.y = extent.lo.y - pos.y;
			d.z = m_neZ - pos.z;
			return d.LengthSqr();
		}
		else if (pos.y > extent.hi.y)
		{
			// position is south-east of area
			return (extent.hi - pos).LengthSqr();
		}
		else
		{
			// position is east of area
			float d = pos.z - extent.hi.x;
			return d * d;
		}
	}
	else if (pos.y < extent.lo.y)
	{
		// position is north of area
		float d = extent.lo.y - pos.y;
		return d * d;
	}
	else if (pos.y > extent.hi.y)
	{
		// position is south of area
		float d = pos.y - extent.hi.y;
		return d * d;
	}
	else
	{
		// position is inside of 2D extent of area - find delta Z
		float z = GetZ( pos );
		float d = z - pos.z;
		return d * d;
	}
}



//--------------------------------------------------------------------------------------------------------------
CNavArea *CNavArea::GetRandomAdjacentArea( NavDirType dir ) const
{
	int count = m_connect[ dir ].Count();
	int which = RandomInt( 0, count-1 );

	int i = 0;
	FOR_EACH_LL( m_connect[ dir ], it )
	{
		if (i == which)
			return m_connect[ dir ][ it ].area;

		++i;
	}

	return NULL;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Compute "portal" between to adjacent areas. 
 * Return center of portal opening, and half-width defining sides of portal from center.
 * NOTE: center->z is unset.
 */
void CNavArea::ComputePortal( const CNavArea *to, NavDirType dir, Vector *center, float *halfWidth ) const
{
	if (dir == NORTH || dir == SOUTH)
	{
		if (dir == NORTH)
			center->y = m_extent.lo.y;
		else
			center->y = m_extent.hi.y;

		float left = MAX( m_extent.lo.x, to->m_extent.lo.x );
		float right = MIN( m_extent.hi.x, to->m_extent.hi.x );

		// clamp to our extent in case areas are disjoint
		if (left < m_extent.lo.x)
			left = m_extent.lo.x;
		else if (left > m_extent.hi.x)
			left = m_extent.hi.x;

		if (right < m_extent.lo.x)
			right = m_extent.lo.x;
		else if (right > m_extent.hi.x)
			right = m_extent.hi.x;

		center->x = (left + right)/2.0f;
		*halfWidth = (right - left)/2.0f;
	}
	else	// EAST or WEST
	{
		if (dir == WEST)
			center->x = m_extent.lo.x;
		else
			center->x = m_extent.hi.x;

		float top = MAX( m_extent.lo.y, to->m_extent.lo.y );
		float bottom = MIN( m_extent.hi.y, to->m_extent.hi.y );

		// clamp to our extent in case areas are disjoint
		if (top < m_extent.lo.y)
			top = m_extent.lo.y;
		else if (top > m_extent.hi.y)
			top = m_extent.hi.y;

		if (bottom < m_extent.lo.y)
			bottom = m_extent.lo.y;
		else if (bottom > m_extent.hi.y)
			bottom = m_extent.hi.y;

		center->y = (top + bottom)/2.0f;
		*halfWidth = (bottom - top)/2.0f;
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Compute closest point within the "portal" between to adjacent areas. 
 */
void CNavArea::ComputeClosestPointInPortal( const CNavArea *to, NavDirType dir, const Vector &fromPos, Vector *closePos ) const
{
	const float margin = GenerationStepSize/2.0f;

	if (dir == NORTH || dir == SOUTH)
	{
		if (dir == NORTH)
			closePos->y = m_extent.lo.y;
		else
			closePos->y = m_extent.hi.y;

		float left = MAX( m_extent.lo.x, to->m_extent.lo.x );
		float right = MIN( m_extent.hi.x, to->m_extent.hi.x );

		// clamp to our extent in case areas are disjoint
		if (left < m_extent.lo.x)
			left = m_extent.lo.x;
		else if (left > m_extent.hi.x)
			left = m_extent.hi.x;

		if (right < m_extent.lo.x)
			right = m_extent.lo.x;
		else if (right > m_extent.hi.x)
			right = m_extent.hi.x;

		// keep margin if against edge
		const float leftMargin = (to->IsEdge( WEST )) ? (left + margin) : left;
		const float rightMargin = (to->IsEdge( EAST )) ? (right - margin) : right;

		// limit x to within portal
		if (fromPos.x < leftMargin)
			closePos->x = leftMargin;
		else if (fromPos.x > rightMargin)
			closePos->x = rightMargin;
		else
			closePos->x = fromPos.x;

	}
	else	// EAST or WEST
	{
		if (dir == WEST)
			closePos->x = m_extent.lo.x;
		else
			closePos->x = m_extent.hi.x;

		float top = MAX( m_extent.lo.y, to->m_extent.lo.y );
		float bottom = MIN( m_extent.hi.y, to->m_extent.hi.y );

		// clamp to our extent in case areas are disjoint
		if (top < m_extent.lo.y)
			top = m_extent.lo.y;
		else if (top > m_extent.hi.y)
			top = m_extent.hi.y;

		if (bottom < m_extent.lo.y)
			bottom = m_extent.lo.y;
		else if (bottom > m_extent.hi.y)
			bottom = m_extent.hi.y;

		// keep margin if against edge
		const float topMargin = (to->IsEdge( NORTH )) ? (top + margin) : top;
		const float bottomMargin = (to->IsEdge( SOUTH )) ? (bottom - margin) : bottom;

		// limit y to within portal
		if (fromPos.y < topMargin)
			closePos->y = topMargin;
		else if (fromPos.y > bottomMargin)
			closePos->y = bottomMargin;
		else
			closePos->y = fromPos.y;
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return true if there are no bi-directional links on the given side
 */
bool CNavArea::IsEdge( NavDirType dir ) const
{
	FOR_EACH_LL( m_connect[ dir ], it )
	{
		const NavConnect connect = m_connect[ dir ][ it ];

		if (connect.area->IsConnected( this, OppositeDirection( dir ) ))
			return false;
	}

	return true;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Return direction from this area to the given point
 */
NavDirType CNavArea::ComputeDirection( Vector *point ) const
{
	if (point->x >= m_extent.lo.x && point->x <= m_extent.hi.x)
	{
		if (point->y < m_extent.lo.y)
			return NORTH;
		else if (point->y > m_extent.hi.y)
			return SOUTH;
	}
	else if (point->y >= m_extent.lo.y && point->y <= m_extent.hi.y)
	{
		if (point->x < m_extent.lo.x)
			return WEST;
		else if (point->x > m_extent.hi.x)
			return EAST;
	}

	// find closest direction
	Vector to = *point - m_center;

	if (fabs(to.x) > fabs(to.y))
	{
		if (to.x > 0.0f)
			return EAST;
		return WEST;
	}
	else
	{
		if (to.y > 0.0f)
			return SOUTH;
		return NORTH;
	}

	return NUM_DIRECTIONS;
}


//--------------------------------------------------------------------------------------------------------------
bool CNavArea::GetCornerHotspot( NavCornerType corner, Vector hotspot[NUM_CORNERS] ) const
{
	Vector nw = GetCorner( NORTH_WEST );
	Vector ne = GetCorner( NORTH_EAST );
	Vector sw = GetCorner( SOUTH_WEST );
	Vector se = GetCorner( SOUTH_EAST );

	float size = 9.0f;
	size = MIN( size, GetSizeX()/3 );	// make sure the hotspot doesn't extend outside small areas
	size = MIN( size, GetSizeY()/3 );

	switch ( corner )
	{
	case NORTH_WEST:
		hotspot[0] = nw;
		hotspot[1] = hotspot[0] + Vector( size, 0, 0 );
		hotspot[2] = hotspot[0] + Vector( size, size, 0 );
		hotspot[3] = hotspot[0] + Vector( 0, size, 0 );
		break;
	case NORTH_EAST:
		hotspot[0] = ne;
		hotspot[1] = hotspot[0] + Vector( -size, 0, 0 );
		hotspot[2] = hotspot[0] + Vector( -size, size, 0 );
		hotspot[3] = hotspot[0] + Vector( 0, size, 0 );
		break;
	case SOUTH_WEST:
		hotspot[0] = sw;
		hotspot[1] = hotspot[0] + Vector( size, 0, 0 );
		hotspot[2] = hotspot[0] + Vector( size, -size, 0 );
		hotspot[3] = hotspot[0] + Vector( 0, -size, 0 );
		break;
	case SOUTH_EAST:
		hotspot[0] = se;
		hotspot[1] = hotspot[0] + Vector( -size, 0, 0 );
		hotspot[2] = hotspot[0] + Vector( -size, -size, 0 );
		hotspot[3] = hotspot[0] + Vector( 0, -size, 0 );
		break;
	default:
		return false;
	}

	for ( int i=1; i<NUM_CORNERS; ++i )
	{
		hotspot[i].z = GetZ( hotspot[i] );
	}

	Vector eyePos, eyeForward;
	TheNavMesh->GetEditVectors( &eyePos, &eyeForward );

	Ray_t ray;
	ray.Init( eyePos, eyePos + 10000.0f * eyeForward, vec3_origin, vec3_origin );

	float dist = IntersectRayWithTriangle( ray, hotspot[0], hotspot[1], hotspot[2], false );
	if ( dist > 0 )
	{
		return true;
	}

	dist = IntersectRayWithTriangle( ray, hotspot[2], hotspot[3], hotspot[0], false );
	if ( dist > 0 )
	{
		return true;
	}

	return false;
}


//--------------------------------------------------------------------------------------------------------------
NavCornerType CNavArea::GetCornerUnderCursor( void ) const
{
	Vector eyePos, eyeForward;
	TheNavMesh->GetEditVectors( &eyePos, &eyeForward );

	for ( int i=0; i<NUM_CORNERS; ++i )
	{
		Vector hotspot[NUM_CORNERS];
		if ( GetCornerHotspot( (NavCornerType)i, hotspot ) )
		{
			return (NavCornerType)i;
		}
	}

	return NUM_CORNERS;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Draw area for debugging
 */
void CNavArea::Draw( void ) const
{
	NavEditColor color;
	bool useAttributeColors = true;

	if ( TheNavMesh->IsPlaceMode() )
	{
		useAttributeColors = false;

		if ( m_place == UNDEFINED_PLACE )
		{
			color = NavNoPlaceColor;
		}
		else if ( TheNavMesh->GetNavPlace() == m_place )
		{
			color = NavSamePlaceColor;
		}
		else
		{
			color = NavDifferentPlaceColor;
		}
	}
	else
	{
		// normal edit mode
		if ( this == TheNavMesh->GetMarkedArea() )
		{
			useAttributeColors = false;
			color = NavMarkedColor;
		}
		else if ( this == TheNavMesh->GetSelectedArea() )
		{
			color = NavSelectedColor;
		}
		else if ( m_isBlocked )
		{
			color = NavBlockedColor;
		}
		else
		{
			color = NavNormalColor;
		}
	}

	if ( IsDegenerate() )
	{
		static IntervalTimer blink;
		static bool blinkOn = false;

		if (blink.GetElapsedTime() > 1.0f)
		{
			blink.Reset();
			blinkOn = !blinkOn;
		}

		useAttributeColors = false;

		if (blinkOn)
			color = NavDegenerateFirstColor;
		else
			color = NavDegenerateSecondColor;

		NDebugOverlay::Text( GetCenter(), UTIL_VarArgs( "Degenerate area %d", GetID() ), true, 0.1f );
	}

	Vector nw, ne, sw, se;

	nw = m_extent.lo;
	se = m_extent.hi;
	ne.x = se.x;
	ne.y = nw.y;
	ne.z = m_neZ;
	sw.x = nw.x;
	sw.y = se.y;
	sw.z = m_swZ;

	int bgcolor[4];
	if ( 4 == sscanf( nav_area_bgcolor.GetString(), "%d %d %d %d", &(bgcolor[0]), &(bgcolor[1]), &(bgcolor[2]), &(bgcolor[3]) ) )
	{
		for ( int i=0; i<4; ++i )
			bgcolor[i] = clamp( bgcolor[i], 0, 255 );

		if ( bgcolor[3] > 0 )
		{
			const Vector offset( 0, 0, 0.8f );
			NDebugOverlay::Triangle( nw+offset, se+offset, ne+offset, bgcolor[0], bgcolor[1], bgcolor[2], bgcolor[3], true, 0.15f );
			NDebugOverlay::Triangle( se+offset, nw+offset, sw+offset, bgcolor[0], bgcolor[1], bgcolor[2], bgcolor[3], true, 0.15f );
		}
	}

	const float inset = 0.2f;
	nw.x += inset;
	nw.y += inset;
	ne.x -= inset;
	ne.y += inset;
	sw.x += inset;
	sw.y -= inset;
	se.x -= inset;
	se.y -= inset;

	if ( GetAttributes() & NAV_MESH_TRANSIENT )
	{
		NavDrawDashedLine( nw, ne, color );
		NavDrawDashedLine( ne, se, color );
		NavDrawDashedLine( se, sw, color );
		NavDrawDashedLine( sw, nw, color );
	}
	else
	{
		NavDrawLine( nw, ne, color );
		NavDrawLine( ne, se, color );
		NavDrawLine( se, sw, color );
		NavDrawLine( sw, nw, color );
	}

	if ( this == TheNavMesh->GetMarkedArea() && TheNavMesh->m_markedCorner != NUM_CORNERS )
	{
		Vector p[NUM_CORNERS];
		GetCornerHotspot( TheNavMesh->m_markedCorner, p );

		NavDrawLine( p[1], p[2], NavMarkedColor );
		NavDrawLine( p[2], p[3], NavMarkedColor );
	}
	if ( this != TheNavMesh->GetMarkedArea() && this == TheNavMesh->GetSelectedArea() && TheNavMesh->m_navEditMode == CNavMesh::NAV_EDIT_NORMAL )
	{
		NavCornerType bestCorner = GetCornerUnderCursor();

		Vector p[NUM_CORNERS];
		GetCornerHotspot( bestCorner, p );

		NavDrawLine( p[1], p[2], NavSelectedColor );
		NavDrawLine( p[2], p[3], NavSelectedColor );
	}

	if (GetAttributes() & NAV_MESH_CROUCH)
	{
		if ( useAttributeColors )
			color = NavAttributeCrouchColor;

		NavDrawLine( nw, se, color );
	}

	if (GetAttributes() & NAV_MESH_JUMP)
	{
		if ( useAttributeColors )
			color = NavAttributeJumpColor;

		if ( !(GetAttributes() & NAV_MESH_CROUCH) )
		{
			NavDrawLine( nw, se, color );
		}
		NavDrawLine( ne, sw, color );
	}

	if (GetAttributes() & NAV_MESH_PRECISE)
	{
		if ( useAttributeColors )
			color = NavAttributePreciseColor;

		float size = 8.0f;
		Vector up( m_center.x, m_center.y - size, m_center.z );
		Vector down( m_center.x, m_center.y + size, m_center.z );
		NavDrawLine( up, down, color );

		Vector left( m_center.x - size, m_center.y, m_center.z );
		Vector right( m_center.x + size, m_center.y, m_center.z );
		NavDrawLine( left, right, color );
	}

	if (GetAttributes() & NAV_MESH_NO_JUMP)
	{
		if ( useAttributeColors )
			color = NavAttributeNoJumpColor;

		float size = 8.0f;
		Vector up( m_center.x, m_center.y - size, m_center.z );
		Vector down( m_center.x, m_center.y + size, m_center.z );
		Vector left( m_center.x - size, m_center.y, m_center.z );
		Vector right( m_center.x + size, m_center.y, m_center.z );
		NavDrawLine( up, right, color );
		NavDrawLine( right, down, color );
		NavDrawLine( down, left, color );
		NavDrawLine( left, up, color );
	}

	// Stop is represented by an octogon
	if (GetAttributes() & NAV_MESH_STOP)
	{
		if ( useAttributeColors )
			color = NavAttributeStopColor;

		float dist = 8.0f;
		float length = dist/2.5f;
		Vector start, end;

		start =	m_center + Vector( dist, -length, 0 );
		end =	m_center + Vector( dist,  length, 0 );
		NavDrawLine( start, end, color );

		start =	m_center + Vector(   dist, length, 0 );
		end =	m_center + Vector( length, dist,   0 );
		NavDrawLine( start, end, color );

		start =	m_center + Vector( -dist, -length, 0 );
		end =	m_center + Vector( -dist,  length, 0 );
		NavDrawLine( start, end, color );

		start =	m_center + Vector( -dist,   length, 0 );
		end =	m_center + Vector( -length, dist,   0 );
		NavDrawLine( start, end, color );

		start =	m_center + Vector( -length,  dist, 0 );
		end =	m_center + Vector(  length,  dist, 0 );
		NavDrawLine( start, end, color );

		start =	m_center + Vector( -dist,   -length, 0 );
		end =	m_center + Vector( -length, -dist,   0 );
		NavDrawLine( start, end, color );

		start =	m_center + Vector( -length, -dist, 0 );
		end =	m_center + Vector(  length, -dist, 0 );
		NavDrawLine( start, end, color );

		start =	m_center + Vector( length, -dist,   0 );
		end =	m_center + Vector( dist,   -length, 0 );
		NavDrawLine( start, end, color );
	}

	// Walk is represented by an arrow
	if (GetAttributes() & NAV_MESH_WALK)
	{
		if ( useAttributeColors )
			color = NavAttributeWalkColor;

		float size = 8.0f;
		NavDrawHorizontalArrow( m_center + Vector( -size, 0, 0 ), m_center + Vector( size, 0, 0 ), 4, color );
	}

	// Walk is represented by a double arrow
	if (GetAttributes() & NAV_MESH_RUN)
	{
		if ( useAttributeColors )
			color = NavAttributeRunColor;

		float size = 8.0f;
		float dist = 4.0f;
		NavDrawHorizontalArrow( m_center + Vector( -size,  dist, 0 ), m_center + Vector( size,  dist, 0 ), 4, color );
		NavDrawHorizontalArrow( m_center + Vector( -size, -dist, 0 ), m_center + Vector( size, -dist, 0 ), 4, color );
	}

	// Avoid is represented by an exclamation point
	if (GetAttributes() & NAV_MESH_AVOID)
	{
		if ( useAttributeColors )
			color = NavAttributeAvoidColor;

		float topHeight = 8.0f;
		float topWidth = 3.0f;
		float bottomHeight = 3.0f;
		float bottomWidth = 2.0f;
		NavDrawTriangle( m_center, m_center + Vector( -topWidth, topHeight, 0 ), m_center + Vector( +topWidth, topHeight, 0 ), color );
		NavDrawTriangle( m_center + Vector( 0, -bottomHeight, 0 ), m_center + Vector( -bottomWidth, -bottomHeight*2, 0 ), m_center + Vector( bottomWidth, -bottomHeight*2, 0 ), color );
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Draw navigation areas and edit them
 */
void CNavArea::DrawHidingSpots( void ) const
{
	const HidingSpotList *list = GetHidingSpotList();

	FOR_EACH_LL( (*list), it )
	{
		const HidingSpot *spot = (*list)[ it ];

		NavEditColor color;

		if (spot->IsIdealSniperSpot())
		{
			color = NavIdealSniperColor;
		}
		else if (spot->IsGoodSniperSpot())
		{
			color = NavGoodSniperColor;
		}
		else if (spot->HasGoodCover())
		{
			color = NavGoodCoverColor;
		}
		else
		{
			color = NavExposedColor;
		}

		NavDrawLine( spot->GetPosition(), spot->GetPosition() + Vector( 0, 0, 50 ), color );
	}
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Draw ourselves and adjacent areas
 */
void CNavArea::DrawConnectedAreas( void ) const
{
	int i;

	CBasePlayer *player = UTIL_GetListenServerHost();
	if (player == NULL)
		return;

	// draw self
	if (TheNavMesh->IsPlaceMode())
	{
		Draw();
	}
	else
	{
		Draw();
		DrawHidingSpots();
	}

	// draw connected ladders
	{
		FOR_EACH_LL( m_ladder[ CNavLadder::LADDER_UP ], it )
		{
			CNavLadder *ladder = m_ladder[ CNavLadder::LADDER_UP ][ it ].ladder;

			ladder->DrawLadder();

			if ( !ladder->IsConnected( this, CNavLadder::LADDER_DOWN ) )
			{
				NavDrawLine( m_center, ladder->m_bottom + Vector( 0, 0, GenerationStepSize ), NavConnectedOneWayColor );
			}
		}
	}
	{
		FOR_EACH_LL( m_ladder[ CNavLadder::LADDER_DOWN ], it )
		{
			CNavLadder *ladder = m_ladder[ CNavLadder::LADDER_DOWN ][ it ].ladder;

			ladder->DrawLadder();

			if ( !ladder->IsConnected( this, CNavLadder::LADDER_UP ) )
			{
				NavDrawLine( m_center, ladder->m_top, NavConnectedOneWayColor );
			}
		}
	}

	// draw connected areas
	for( i=0; i<NUM_DIRECTIONS; ++i )
	{
		NavDirType dir = (NavDirType)i;

		int count = GetAdjacentCount( dir );

		for( int a=0; a<count; ++a )
		{
			CNavArea *adj = GetAdjacentArea( dir, a );

			adj->Draw();

			if ( !TheNavMesh->IsPlaceMode() )
			{
				adj->DrawHidingSpots();

				Vector from = Vector(0.0f, 0.0f, 0.0f), to = Vector(0.0f, 0.0f, 0.0f);
				Vector hookPos = Vector(0.0f, 0.0f, 0.0f);
				float halfWidth;
				float size = 5.0f;
				ComputePortal( adj, dir, &hookPos, &halfWidth );

				switch( dir )
				{
					case NORTH:
						from = hookPos + Vector( 0.0f, size, 0.0f );
						to = hookPos + Vector( 0.0f, -size, 0.0f );
						break;
					case SOUTH:
						from = hookPos + Vector( 0.0f, -size, 0.0f );
						to = hookPos + Vector( 0.0f, size, 0.0f );
						break;
					case EAST:
						from = hookPos + Vector( -size, 0.0f, 0.0f );
						to = hookPos + Vector( +size, 0.0f, 0.0f );
						break;
					case WEST:
						from = hookPos + Vector( size, 0.0f, 0.0f );
						to = hookPos + Vector( -size, 0.0f, 0.0f );
						break;
					default:
						break;
				}

				from.z = GetZ( from );
				to.z = adj->GetZ( to );

				Vector drawTo;
				adj->GetClosestPointOnArea( to, &drawTo );

				if (adj->IsConnected( this, OppositeDirection( dir ) ) )
					NavDrawLine( from, drawTo, NavConnectedTwoWaysColor );
				else
					NavDrawLine( from, drawTo, NavConnectedOneWayColor );
			}
		}
	}
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Add to open list in decreasing value order
 */
void CNavArea::AddToOpenList( void )
{
	// mark as being on open list for quick check
	m_openMarker = m_masterMarker;

	// if list is empty, add and return
	if (m_openList == NULL)
	{
		m_openList = this;
		this->m_prevOpen = NULL;
		this->m_nextOpen = NULL;
		return;
	}

	// insert self in ascending cost order
	CNavArea *area, *last = NULL;
	for( area = m_openList; area; area = area->m_nextOpen )
	{
		if (this->GetTotalCost() < area->GetTotalCost())
			break;

		last = area;
	}

	if (area)
	{
		// insert before this area
		this->m_prevOpen = area->m_prevOpen;
		if (this->m_prevOpen)
			this->m_prevOpen->m_nextOpen = this;
		else
			m_openList = this;

		this->m_nextOpen = area;
		area->m_prevOpen = this;
	}
	else
	{
		// append to end of list
		last->m_nextOpen = this;

		this->m_prevOpen = last;
		this->m_nextOpen = NULL;
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * A smaller value has been found, update this area on the open list
 * @todo "bubbling" does unnecessary work, since the order of all other nodes will be unchanged - only this node is altered
 */
void CNavArea::UpdateOnOpenList( void )
{
	// since value can only decrease, bubble this area up from current spot
	while( m_prevOpen && 
				 this->GetTotalCost() < m_prevOpen->GetTotalCost() )
	{
		// swap position with predecessor
		CNavArea *other = m_prevOpen;
		CNavArea *before = other->m_prevOpen;
		CNavArea *after  = this->m_nextOpen;

		this->m_nextOpen = other;
		this->m_prevOpen = before;

		other->m_prevOpen = this;
		other->m_nextOpen = after;

		if (before)
			before->m_nextOpen = this;
		else
			m_openList = this;

		if (after)
			after->m_prevOpen = other;
	}
}

//--------------------------------------------------------------------------------------------------------------
void CNavArea::RemoveFromOpenList( void )
{
	if (m_prevOpen)
		m_prevOpen->m_nextOpen = m_nextOpen;
	else
		m_openList = m_nextOpen;

	if (m_nextOpen)
		m_nextOpen->m_prevOpen = m_prevOpen;

	// zero is an invalid marker
	m_openMarker = 0;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Clears the open and closed lists for a new search
 */
void CNavArea::ClearSearchLists( void )
{
	// effectively clears all open list pointers and closed flags
	CNavArea::MakeNewMarker();

	m_openList = NULL;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return the coordinates of the area's corner.
 * NOTE: Do not retain the returned pointer - it is temporary.
 */
const Vector &CNavArea::GetCorner( NavCornerType corner ) const
{
	static Vector pos;

	switch( corner )
	{
		default:
			Assert( false && "GetCorner: Invalid type" );
		case NORTH_WEST:
			return m_extent.lo;

		case NORTH_EAST:
			pos.x = m_extent.hi.x;
			pos.y = m_extent.lo.y;
			pos.z = m_neZ;
			return pos;

		case SOUTH_WEST:
			pos.x = m_extent.lo.x;
			pos.y = m_extent.hi.y;
			pos.z = m_swZ;
			return pos;

		case SOUTH_EAST:
			return m_extent.hi;
	}
}


//--------------------------------------------------------------------------------------------------------------
void CNavArea::SetCorner( NavCornerType corner, const Vector& newPosition )
{
	switch( corner )
	{
		case NORTH_WEST:
			m_extent.lo = newPosition;
			break;

		case NORTH_EAST:
			m_extent.hi.x = newPosition.x;
			m_extent.lo.y = newPosition.y;
			m_neZ = newPosition.z;
			break;

		case SOUTH_WEST:
			m_extent.lo.x = newPosition.x;
			m_extent.hi.y = newPosition.y;
			m_swZ = newPosition.z;
			break;

		case SOUTH_EAST:
			m_extent.hi = newPosition;
			break;

		default:
		{
			Vector oldPosition = GetCenter();
			Vector delta = newPosition - oldPosition;
			m_extent.lo += delta;
			m_extent.hi += delta;
			m_neZ += delta.z;
			m_swZ += delta.z;
		}
	}

	m_center.x = (m_extent.lo.x + m_extent.hi.x)/2.0f;
	m_center.y = (m_extent.lo.y + m_extent.hi.y)/2.0f;
	m_center.z = (m_extent.lo.z + m_extent.hi.z)/2.0f;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Returns true if an existing hiding spot is too close to given position
 */
bool CNavArea::IsHidingSpotCollision( const Vector &pos ) const
{
	const float collisionRange = 30.0f;

	FOR_EACH_LL( m_hidingSpotList, it )
	{
		const HidingSpot *spot = m_hidingSpotList[ it ];

		if ((spot->GetPosition() - pos).IsLengthLessThan( collisionRange ))
			return true;
	}

	return false;
}

//--------------------------------------------------------------------------------------------------------------
bool IsHidingSpotInCover( const Vector &spot )
{
	int coverCount = 0;
	trace_t result;

	Vector from = spot;
	from.z += HalfHumanHeight;

	Vector to;

	// if we are crouched underneath something, that counts as good cover
	to = from + Vector( 0, 0, 20.0f );
	UTIL_TraceLine( from, to, MASK_PLAYERSOLID_BRUSHONLY, NULL, COLLISION_GROUP_NONE, &result );
	if (result.fraction != 1.0f)
		return true;

	const float coverRange = 100.0f;
	const float inc = M_PI / 8.0f;

	for( float angle = 0.0f; angle < 2.0f * M_PI; angle += inc )
	{
		to = from + Vector( coverRange * (float)cos(angle), coverRange * (float)sin(angle), HalfHumanHeight );

		UTIL_TraceLine( from, to, MASK_PLAYERSOLID_BRUSHONLY, NULL, COLLISION_GROUP_NONE, &result );

		// if traceline hit something, it hit "cover"
		if (result.fraction != 1.0f)
			++coverCount;
	}

	// if more than half of the circle has no cover, the spot is not "in cover"
	const int halfCover = 8;
	if (coverCount < halfCover)
		return false;

	return true;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Finds the hiding spot position in a corner's area.  If the typical inset is off the nav area (small
 * hand-constructed areas), it tries to fit the position inside the area.
 */
static Vector FindPositionInArea( CNavArea *area, NavCornerType corner )
{
	int multX = 1, multY = 1;
	switch ( corner )
	{
	case NORTH_WEST:
		break;
	case NORTH_EAST:
		multX = -1;
		break;
	case SOUTH_WEST:
		multY = -1;
		break;
	case SOUTH_EAST:
		multX = -1;
		multY = -1;
		break;
	default:
		break;
	}

	const float offset = 12.5f;
	Vector cornerPos = area->GetCorner( corner );

	// Try the basic inset
	Vector pos = cornerPos + Vector(  offset*multX,  offset*multY, 0.0f );
	if ( !area->IsOverlapping( pos ) )
	{
		// Try pulling the Y offset to the area's center
		pos = cornerPos + Vector(  offset*multX,  area->GetSizeY()*0.5f*multY, 0.0f );
		if ( !area->IsOverlapping( pos ) )
		{
			// Try pulling the X offset to the area's center
			pos = cornerPos + Vector(  area->GetSizeX()*0.5f*multX,  offset*multY, 0.0f );
			if ( !area->IsOverlapping( pos ) )
			{
				// Try pulling the X and Y offsets to the area's center
				pos = cornerPos + Vector(  area->GetSizeX()*0.5f*multX,  area->GetSizeY()*0.5f*multY, 0.0f );
				if ( !area->IsOverlapping( pos ) )
				{
					AssertMsg( false, UTIL_VarArgs( "A Hiding Spot can't be placed on its area at (%.0f %.0f %.0f)", cornerPos.x, cornerPos.y, cornerPos.z) );

					// Just pull the position to a small offset
					pos = cornerPos + Vector(  1.0f*multX,  1.0f*multY, 0.0f );
					if ( !area->IsOverlapping( pos ) )
					{
						// Nothing is working (degenerate area?), so just put it directly on the corner
						pos = cornerPos;
					}
				}
			}
		}
	}

	return pos;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Analyze local area neighborhood to find "hiding spots" for this area
 */
void CNavArea::ComputeHidingSpots( void )
{
	struct
	{
		float lo, hi;
	}
	extent;

	m_hidingSpotList.PurgeAndDeleteElements();


	// "jump areas" cannot have hiding spots
	if ( GetAttributes() & NAV_MESH_JUMP )
		return;

	// "don't hide areas" cannot have hiding spots
	if ( GetAttributes() & NAV_MESH_DONT_HIDE )
		return;

	int cornerCount[NUM_CORNERS];
	for( int i=0; i<NUM_CORNERS; ++i )
		cornerCount[i] = 0;

	const float cornerSize = 20.0f;

	// for each direction, find extents of adjacent areas along the wall
	for( int d=0; d<NUM_DIRECTIONS; ++d )
	{
		extent.lo = 999999.9f;
		extent.hi = -999999.9f;

		bool isHoriz = (d == NORTH || d == SOUTH) ? true : false;

		FOR_EACH_LL( m_connect[d], it )
		{
			NavConnect connect = m_connect[ d ][ it ];

			// if connection is only one-way, it's a "jump down" connection (ie: a discontinuity that may mean cover) 
			// ignore it
			if (connect.area->IsConnected( this, OppositeDirection( static_cast<NavDirType>( d ) ) ) == false)
				continue;

			// ignore jump areas
			if (connect.area->GetAttributes() & NAV_MESH_JUMP)
				continue;

			if (isHoriz)
			{
				if (connect.area->m_extent.lo.x < extent.lo)
					extent.lo = connect.area->m_extent.lo.x;

				if (connect.area->m_extent.hi.x > extent.hi)
					extent.hi = connect.area->m_extent.hi.x;			
			}
			else
			{
				if (connect.area->m_extent.lo.y < extent.lo)
					extent.lo = connect.area->m_extent.lo.y;

				if (connect.area->m_extent.hi.y > extent.hi)
					extent.hi = connect.area->m_extent.hi.y;
			}
		}

		switch( d )
		{
			case NORTH:
				if (extent.lo - m_extent.lo.x >= cornerSize)
					++cornerCount[ NORTH_WEST ];

				if (m_extent.hi.x - extent.hi >= cornerSize)
					++cornerCount[ NORTH_EAST ];
				break;

			case SOUTH:
				if (extent.lo - m_extent.lo.x >= cornerSize)
					++cornerCount[ SOUTH_WEST ];

				if (m_extent.hi.x - extent.hi >= cornerSize)
					++cornerCount[ SOUTH_EAST ];
				break;

			case EAST:
				if (extent.lo - m_extent.lo.y >= cornerSize)
					++cornerCount[ NORTH_EAST ];

				if (m_extent.hi.y - extent.hi >= cornerSize)
					++cornerCount[ SOUTH_EAST ];
				break;

			case WEST:
				if (extent.lo - m_extent.lo.y >= cornerSize)
					++cornerCount[ NORTH_WEST ];

				if (m_extent.hi.y - extent.hi >= cornerSize)
					++cornerCount[ SOUTH_WEST ];
				break;
		}
	}

	for ( int c=0; c<NUM_CORNERS; ++c )
	{
		// if a corner count is 2, then it really is a corner (walls on both sides)
		if (cornerCount[c] == 2)
		{
			Vector pos = FindPositionInArea( this, (NavCornerType)c );
			if ( !c || !IsHidingSpotCollision( pos ) )
			{
				HidingSpot *spot = TheNavMesh->CreateHidingSpot();
				spot->SetPosition( pos );
				spot->SetFlags( IsHidingSpotInCover( pos ) ? HidingSpot::IN_COVER : HidingSpot::EXPOSED );
				m_hidingSpotList.AddToTail( spot );
			}
		}
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Determine how much walkable area we can see from the spot, and how far away we can see.
 */
void ClassifySniperSpot( HidingSpot *spot )
{
	Vector eye = spot->GetPosition();

	CNavArea *hidingArea = TheNavMesh->GetNavArea( spot->GetPosition() );
	if (hidingArea && (hidingArea->GetAttributes() & NAV_MESH_STAND))
	{
		// we will be standing at this hiding spot
		eye += Vector( 0, 0, 0.8f * HumanHeight );
	}
	else
	{
		// we are crouching when at this hiding spot
		eye += Vector( 0, 0, HalfHumanHeight );
	}

	Vector walkable;
	trace_t result;

	Extent sniperExtent;
	float farthestRangeSq = 0.0f;
	const float minSniperRangeSq = 1000.0f * 1000.0f;
	bool found = false;

	// to make compiler stop warning me
	sniperExtent.lo = Vector( 0.0f, 0.0f, 0.0f );
	sniperExtent.hi = Vector( 0.0f, 0.0f, 0.0f );

	FOR_EACH_LL( TheNavAreaList, it )
	{
		CNavArea *area = TheNavAreaList[ it ];

		const Extent &extent = area->GetExtent();

		// scan this area
		for( walkable.y = extent.lo.y + GenerationStepSize/2.0f; walkable.y < extent.hi.y; walkable.y += GenerationStepSize )
		{
			for( walkable.x = extent.lo.x + GenerationStepSize/2.0f; walkable.x < extent.hi.x; walkable.x += GenerationStepSize )
			{
				walkable.z = area->GetZ( walkable ) + HalfHumanHeight;
				
				// check line of sight
				UTIL_TraceLine( eye, walkable, CONTENTS_SOLID|CONTENTS_MOVEABLE|CONTENTS_PLAYERCLIP, NULL, COLLISION_GROUP_NONE, &result );

				if (result.fraction == 1.0f && !result.startsolid)
				{
					// can see this spot

					// keep track of how far we can see
					float rangeSq = (eye - walkable).LengthSqr();
					if (rangeSq > farthestRangeSq)
					{
						farthestRangeSq = rangeSq;

						if (rangeSq >= minSniperRangeSq)
						{
							// this is a sniper spot
							// determine how good of a sniper spot it is by keeping track of the snipable area
							if (found)
							{
								if (walkable.x < sniperExtent.lo.x)
									sniperExtent.lo.x = walkable.x;
								if (walkable.x > sniperExtent.hi.x)
									sniperExtent.hi.x = walkable.x;

								if (walkable.y < sniperExtent.lo.y)
									sniperExtent.lo.y = walkable.y;
								if (walkable.y > sniperExtent.hi.y)
									sniperExtent.hi.y = walkable.y;
							}
							else
							{
								sniperExtent.lo = walkable;
								sniperExtent.hi = walkable;
								found = true;
							}
						}
					}
				}	
			}
		}
	}

	if (found)
	{
		// if we can see a large snipable area, it is an "ideal" spot
		float snipableArea = sniperExtent.Area();

		const float minIdealSniperArea = 200.0f * 200.0f;
		const float longSniperRangeSq = 1500.0f * 1500.0f;

		if (snipableArea >= minIdealSniperArea || farthestRangeSq >= longSniperRangeSq)
			spot->m_flags |= HidingSpot::IDEAL_SNIPER_SPOT;
		else
			spot->m_flags |= HidingSpot::GOOD_SNIPER_SPOT;
	}
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Analyze local area neighborhood to find "sniper spots" for this area
 */
void CNavArea::ComputeSniperSpots( void )
{
	if (nav_quicksave.GetBool())
		return;

	FOR_EACH_LL( m_hidingSpotList, it )
	{
		HidingSpot *spot = m_hidingSpotList[ it ];

		ClassifySniperSpot( spot );
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Given the areas we are moving between, return the spots we will encounter
 */
SpotEncounter *CNavArea::GetSpotEncounter( const CNavArea *from, const CNavArea *to )
{
	if (from && to)
	{
		SpotEncounter *e;

		FOR_EACH_LL( m_spotEncounterList, it )
		{
			e = m_spotEncounterList[ it ];

			if (e->from.area == from && e->to.area == to)
				return e;
		}
	}

	return NULL;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Add spot encounter data when moving from area to area
 */
void CNavArea::AddSpotEncounters( const CNavArea *from, NavDirType fromDir, const CNavArea *to, NavDirType toDir )
{
	SpotEncounter *e = new SpotEncounter;

	e->from.area = const_cast<CNavArea *>( from );
	e->fromDir = fromDir;

	e->to.area = const_cast<CNavArea *>( to );
	e->toDir = toDir;

	float halfWidth;
	ComputePortal( to, toDir, &e->path.to, &halfWidth );
	ComputePortal( from, fromDir, &e->path.from, &halfWidth );

	const float eyeHeight = HalfHumanHeight;
	e->path.from.z = from->GetZ( e->path.from ) + eyeHeight;
	e->path.to.z = to->GetZ( e->path.to ) + eyeHeight;

	// step along ray and track which spots can be seen
	Vector dir = e->path.to - e->path.from;
	float length = dir.NormalizeInPlace();

	// create unique marker to flag used spots
	HidingSpot::ChangeMasterMarker();

	const float stepSize = 25.0f;		// 50
	const float seeSpotRange = 2000.0f;	// 3000
	trace_t result;

	Vector eye, delta;
	HidingSpot *spot;
	SpotOrder spotOrder;

	// step along path thru this area
	bool done = false;
	for( float along = 0.0f; !done; along += stepSize )
	{
		// make sure we check the endpoint of the path segment
		if (along >= length)
		{
			along = length;
			done = true;
		}

		// move the eyepoint along the path segment
		eye = e->path.from + along * dir;

		// check each hiding spot for visibility
		FOR_EACH_LL( TheHidingSpotList, it )
		{
			spot = TheHidingSpotList[ it ];

			// only look at spots with cover (others are out in the open and easily seen)
			if (!spot->HasGoodCover())
				continue;

			if (spot->IsMarked())
				continue;

			const Vector &spotPos = spot->GetPosition();

			delta.x = spotPos.x - eye.x;
			delta.y = spotPos.y - eye.y;
			delta.z = (spotPos.z + eyeHeight) - eye.z;

			// check if in range
			if (delta.IsLengthGreaterThan( seeSpotRange ))
				continue;

			// check if we have LOS
			// BOTPORT: ignore glass here
			UTIL_TraceLine( eye, Vector( spotPos.x, spotPos.y, spotPos.z + HalfHumanHeight ), MASK_PLAYERSOLID_BRUSHONLY, NULL, COLLISION_GROUP_NONE, &result );
			if (result.fraction != 1.0f)
				continue;

			// if spot is in front of us along our path, ignore it
			delta.NormalizeInPlace();
			float dot = DotProduct( dir, delta );
			if (dot < 0.7071f && dot > -0.7071f)
			{
				// we only want to keep spots that BECOME visible as we walk past them
				// therefore, skip ALL visible spots at the start of the path segment
				if (along > 0.0f)
				{
					// add spot to encounter
					spotOrder.spot = spot;
					spotOrder.t = along/length;
					e->spotList.AddToTail( spotOrder );
				}
			}

			// mark spot as encountered
			spot->Mark();
		}
	}

	// add encounter to list
	m_spotEncounterList.AddToTail( e );
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Compute "spot encounter" data. This is an ordered list of spots to look at 
 * for each possible path thru a nav area.
 */
void CNavArea::ComputeSpotEncounters( void )
{
	m_spotEncounterList.RemoveAll();

	if (nav_quicksave.GetBool())
		return;

	// for each adjacent area
	for( int fromDir=0; fromDir<NUM_DIRECTIONS; ++fromDir )
	{
		FOR_EACH_LL( m_connect[ fromDir ], it )
		{
			NavConnect *fromCon = &(m_connect[ fromDir ][ it ]);

			// compute encounter data for path to each adjacent area
			for( int toDir=0; toDir<NUM_DIRECTIONS; ++toDir )
			{
				FOR_EACH_LL( m_connect[ toDir ], ot )
				{
					NavConnect *toCon = &(m_connect[ toDir ][ ot ]);

					if (toCon == fromCon)
						continue;

					// just do our direction, as we'll loop around for other direction
					AddSpotEncounters( fromCon->area, (NavDirType)fromDir, toCon->area, (NavDirType)toDir );
				}
			}
		}
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Decay the danger values
 */
void CNavArea::DecayDanger( void )
{
	// one kill == 1.0, which we will forget about in two minutes
	const float decayRate = 1.0f / 120.0f;

	for( int i=0; i<MAX_NAV_TEAMS; ++i )
	{
		float deltaT = gpGlobals->curtime - m_dangerTimestamp[i];
		float decayAmount = decayRate * deltaT;

		m_danger[i] -= decayAmount;
		if (m_danger[i] < 0.0f)
			m_danger[i] = 0.0f;

		// update timestamp
		m_dangerTimestamp[i] = gpGlobals->curtime;
	}
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Increase the danger of this area for the given team
 */
void CNavArea::IncreaseDanger( int teamID, float amount )
{
	// before we add the new value, decay what's there
	DecayDanger();

	int teamIdx = teamID % MAX_NAV_TEAMS;

	m_danger[ teamIdx ] += amount;
	m_dangerTimestamp[ teamIdx ] = gpGlobals->curtime;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Return the danger of this area (decays over time)
 */
float CNavArea::GetDanger( int teamID )
{
	DecayDanger();

	int teamIdx = teamID % MAX_NAV_TEAMS;
	return m_danger[ teamIdx ];
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Raise/lower a corner
 */
void CNavArea::RaiseCorner( NavCornerType corner, int amount, bool raiseAdjacentCorners )
{
	if ( corner == NUM_CORNERS )
	{
		RaiseCorner( NORTH_WEST, amount, raiseAdjacentCorners );
		RaiseCorner( NORTH_EAST, amount, raiseAdjacentCorners );
		RaiseCorner( SOUTH_WEST, amount, raiseAdjacentCorners );
		RaiseCorner( SOUTH_EAST, amount, raiseAdjacentCorners );
		return;
	}

	// Move the corner
	switch (corner)
	{
	case NORTH_WEST:
		m_extent.lo.z += amount;
		break;
	case NORTH_EAST:
		m_neZ += amount;
		break;
	case SOUTH_WEST:
		m_swZ += amount;
		break;
	case SOUTH_EAST:
		m_extent.hi.z += amount;
		break;
	default:
		break;
	}

	// Recompute the center
	m_center.x = (m_extent.lo.x + m_extent.hi.x)/2.0f;
	m_center.y = (m_extent.lo.y + m_extent.hi.y)/2.0f;
	m_center.z = (m_extent.lo.z + m_extent.hi.z)/2.0f;

	if ( !raiseAdjacentCorners || nav_corner_adjust_adjacent.GetFloat() <= 0.0f )
	{
		return;
	}

	// Find nearby areas that share the corner
	CNavArea::MakeNewMarker();
	Mark();

	const float tolerance = nav_corner_adjust_adjacent.GetFloat();

	Vector cornerPos = GetCorner( corner );
	cornerPos.z -= amount; // use the pre-adjustment corner for adjacency checks

	int gridX = TheNavMesh->WorldToGridX( cornerPos.x );
	int gridY = TheNavMesh->WorldToGridY( cornerPos.y );

	const int shift = 1; // try a 3x3 set of grids in case we're on the edge

	for( int x = gridX - shift; x <= gridX + shift; ++x )
	{
		if (x < 0 || x >= TheNavMesh->m_gridSizeX)
			continue;

		for( int y = gridY - shift; y <= gridY + shift; ++y )
		{
			if (y < 0 || y >= TheNavMesh->m_gridSizeY)
				continue;

			NavAreaList *list = &TheNavMesh->m_grid[ x + y*TheNavMesh->m_gridSizeX ];

			// find closest area in this cell
			FOR_EACH_LL( (*list), it )
			{
				CNavArea *area = (*list)[ it ];

				// skip if we've already visited this area
				if (area->IsMarked())
					continue;

				area->Mark();

				Vector areaPos;
				for ( int i=0; i<NUM_CORNERS; ++i )
				{
					areaPos = area->GetCorner( NavCornerType(i) );
					if ( areaPos.DistTo( cornerPos ) < tolerance )
					{
						float heightDiff = (cornerPos.z + amount ) - areaPos.z;
						area->RaiseCorner( NavCornerType(i), (int)heightDiff, false );
					}
				}
			}
		}
	}
}


//--------------------------------------------------------------------------------------------------------------
/**
 * FindGroundZFromPoint walks from the start position to the end position in GenerationStepSize increments,
 * checking the ground height along the way.
 */
float FindGroundZFromPoint( const Vector& end, const Vector& start )
{
	Vector step( 0, 0, StepHeight );
	if ( fabs( end.x - start.x ) > fabs( end.y - start.y ) )
	{
		step.x = GenerationStepSize;
		if ( end.x < start.x )
		{
			step.x = -step.x;
		}
	}
	else
	{
		step.y = GenerationStepSize;
		if ( end.y < start.y )
		{
			step.y = -step.y;
		}
	}

	// step towards our end point
	Vector point = start;
	float z;
	while ( point.AsVector2D().DistTo( end.AsVector2D() ) > GenerationStepSize )
	{
		point = point + step;
		z = point.z;
		if ( TheNavMesh->GetGroundHeight( point, &z ) )
		{
			point.z = z;
		}
		else
		{
			point.z -= step.z;
		}
	}

	// now do the exact one once we're within GenerationStepSize of it
	z = point.z + step.z;
	point = end;
	point.z = z;
	if ( TheNavMesh->GetGroundHeight( point, &z ) )
	{
		point.z = z;
	}
	else
	{
		point.z -= step.z;
	}

	return point.z;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Finds the Z value for a corner given two other corner points.  This walks along the edges of the nav area
 * in GenerationStepSize increments, to increase accuracy.
 */
float FindGroundZ( const Vector& original, const Vector& corner1, const Vector& corner2 )
{
	float first = FindGroundZFromPoint( original, corner1 );
	float second = FindGroundZFromPoint( original, corner2 );

	if ( fabs( first - second ) > StepHeight )
	{
		// approaching the point from the two directions didn't agree.  Take the one closest to the original z.
		if ( fabs( original.z - first ) > fabs( original.z - second ) )
		{
			return second;
		}
		else
		{
			return first;
		}
	}

	return first;
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Places a corner (or all corners if corner == NUM_CORNERS) on the ground
 */
void CNavArea::PlaceOnGround( NavCornerType corner, float inset )
{
	trace_t result;
	Vector from, to;

	Vector nw = m_extent.lo + Vector ( inset, inset, 0 );
	Vector se = m_extent.hi + Vector ( -inset, -inset, 0 );
	Vector ne, sw;
	ne.x = se.x;
	ne.y = nw.y;
	ne.z = m_neZ;
	sw.x = nw.x;
	sw.y = se.y;
	sw.z = m_swZ;

	if ( corner == NORTH_WEST || corner == NUM_CORNERS )
	{
		float newZ = FindGroundZ( nw, ne, sw );
		RaiseCorner( NORTH_WEST, static_cast<int>(newZ - nw.z) );
	}

	if ( corner == NORTH_EAST || corner == NUM_CORNERS )
	{
		float newZ = FindGroundZ( ne, nw, se );
		RaiseCorner( NORTH_EAST, static_cast<int>(newZ - ne.z) );
	}

	if ( corner == SOUTH_WEST || corner == NUM_CORNERS )
	{
		float newZ = FindGroundZ( sw, nw, se );
		RaiseCorner( SOUTH_WEST, static_cast<int>(newZ - sw.z) );
	}

	if ( corner == SOUTH_EAST || corner == NUM_CORNERS )
	{
		float newZ = FindGroundZ( se, ne, sw );
		RaiseCorner( SOUTH_EAST, static_cast<int>(newZ - se.z) );
	}
}


//--------------------------------------------------------------------------------------------------------------
static void CommandNavUpdateBlocked( void )
{
	if ( !UTIL_IsCommandIssuedByServerAdmin() )
		return;

	if ( TheNavMesh->GetMarkedArea() )
	{
		CNavArea *area = TheNavMesh->GetMarkedArea();
		area->UpdateBlocked();
		if ( area->IsBlocked() )
		{
			DevMsg( "Area #%d %s is blocked\n", area->GetID(), VecToString( area->GetCenter() + Vector( 0, 0, HalfHumanHeight ) ) );
		}
	}
	else
	{
		float start = engine->Time();
		CNavArea *blockedArea = NULL;
		FOR_EACH_LL( TheNavAreaList, nit )
		{
			CNavArea *area = TheNavAreaList[ nit ];
			area->UpdateBlocked();
			if ( area->IsBlocked() )
			{
				DevMsg( "Area #%d %s is blocked\n", area->GetID(), VecToString( area->GetCenter() + Vector( 0, 0, HalfHumanHeight ) ) );
				if ( !blockedArea )
				{
					blockedArea = area;
				}
			}
		}

		float end = engine->Time();
		float time = (end - start) * 1000.0f;
		DevMsg( "nav_update_blocked took %2.2f ms\n", time );

		if ( blockedArea )
		{
			CBasePlayer *player = UTIL_GetListenServerHost();
			if ( player )
			{
				if ( ( player->IsDead() || player->IsObserver() ) && player->GetObserverMode() == OBS_MODE_ROAMING )
				{
					Vector origin = blockedArea->GetCenter() + Vector( 0, 0, 0.75f * HumanHeight );
					UTIL_SetOrigin( player, origin );
				}
			}
		}
	}
}
static ConCommand nav_update_blocked( "nav_update_blocked", CommandNavUpdateBlocked, "Updates the blocked/unblocked status for every nav area.", FCVAR_GAMEDLL );


//-----------------------------------------------------------------------------------------------------
class CNavBlockerEnumerator : public IPartitionEnumerator
{
public:
	// Forced constructor
	CNavBlockerEnumerator(CBaseEntity **ents, int nMaxEnts)
	{
		m_nAlreadyHit = 0;
		m_AlreadyHit = ents;
		m_nMaxHits = nMaxEnts;
	}
	
	// Actual work code
	virtual IterationRetval_t EnumElement( IHandleEntity *pHandleEntity )
	{
		CBaseEntity *pEnt = gEntList.GetBaseEntity( pHandleEntity->GetRefEHandle() );

		if ( pEnt == NULL )
			return ITERATION_CONTINUE;

		if ( pEnt->GetCollisionGroup() != COLLISION_GROUP_PUSHAWAY && pEnt->GetCollisionGroup() != COLLISION_GROUP_BREAKABLE_GLASS && pEnt->GetCollisionGroup() != COLLISION_GROUP_PLAYER && pEnt->GetCollisionGroup() != COLLISION_GROUP_NONE )
			return ITERATION_CONTINUE;

		IMultiplayerPhysics *pInterface = dynamic_cast<IMultiplayerPhysics*>( pEnt );
		if ( pInterface )
		{
			if ( pInterface->GetMultiplayerPhysicsMode() != PHYSICS_MULTIPLAYER_SOLID )
				return ITERATION_CONTINUE;
		}
		else
		{
			if ((FClassnameIs( pEnt, "func_breakable" ) || FClassnameIs( pEnt, "func_breakable_surf" )))
			{
				bool isBreakable = true;

				// If we won't be able to break it, don't try
				if ( pEnt->m_takedamage != DAMAGE_YES )
				{
					isBreakable = false;
				}

				if ( !isBreakable )
					return ITERATION_CONTINUE;
			}
			else if ( FClassnameIs( pEnt, "func_door*" ) ) // doors
			{
			}
			else if ( FClassnameIs( pEnt, "prop_door*" ) ) // doors
			{
			}
			else
			{
				return ITERATION_CONTINUE;
			}
		}

		if ( m_nAlreadyHit < m_nMaxHits )
		{
			m_AlreadyHit[m_nAlreadyHit] = pEnt;
			m_nAlreadyHit++;
		}

		return ITERATION_CONTINUE;
	}

public:

	CBaseEntity **m_AlreadyHit;
	int m_nAlreadyHit;
	int m_nMaxHits;
};


//-----------------------------------------------------------------------------------------------------
/*static int GetPushawayEntsInVolume( const Vector& origin, const Vector& mins, const Vector& maxs, CBaseEntity **ents, int nMaxEnts, int PartitionMask, CNavBlockerEnumerator *enumerator )
{
	Ray_t ray;
	ray.Init( origin, origin, mins, maxs );

	CNavBlockerEnumerator *physPropEnum = NULL;
	if  ( !enumerator )
	{
		physPropEnum = new CNavBlockerEnumerator( ents, nMaxEnts );
		enumerator = physPropEnum;
	}

	partition->EnumerateElementsAlongRay( PartitionMask, ray, false, enumerator );

	int numHit = enumerator->m_nAlreadyHit;

	if ( physPropEnum )
		delete physPropEnum;

	return numHit;
}*/


//--------------------------------------------------------------------------------------------------------------
/**
 * Updates the (un)blocked status of the nav area
 */
void CNavArea::UpdateBlocked( void )
{
	Vector origin = GetCenter();
	origin.z += HalfHumanHeight;

	const float sizeX = MAX( 1, MIN( GetSizeX()/2 - 5, HalfHumanWidth ) );
	const float sizeY = MAX( 1, MIN( GetSizeY()/2 - 5, HalfHumanWidth ) );
	Vector mins( -sizeX, -sizeY, 0 );
	Vector maxs( sizeX, sizeY, VEC_DUCK_HULL_MAX.z );

	maxs.z -= HalfHumanHeight;

	bool wasBlocked = m_isBlocked;

	// See if spot is valid
	CTraceFilterWalkableEntities filter( NULL, COLLISION_GROUP_PLAYER_MOVEMENT, WALK_THRU_DOORS | WALK_THRU_BREAKABLES );
	trace_t tr;
	UTIL_TraceHull(
		origin,
		origin,
		mins,
		maxs,
		MASK_PLAYERSOLID_BRUSHONLY,
		&filter,
		&tr );

	m_isBlocked = tr.startsolid;

	if ( wasBlocked != m_isBlocked )
	{
		IGameEvent * event = gameeventmanager->CreateEvent( "nav_blocked" );
		if ( event )
		{
			event->SetInt( "area", m_id );
			event->SetInt( "blocked", m_isBlocked );
			gameeventmanager->FireEvent( event );
		}
	}

	/*
	if ( m_isBlocked )
	{
		NDebugOverlay::Box( origin, mins, maxs, 255, 0, 0, 64, 3.0f );
	}
	else
	{
		NDebugOverlay::Box( origin, mins, maxs, 0, 255, 0, 64, 3.0f );
	}
	*/
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Checks if there is a floor under the nav area, in case a breakable floor is gone
 */
void CNavArea::CheckFloor( CBaseEntity *ignore )
{
	if ( m_isBlocked )
		return;

	Vector origin = GetCenter();
	origin.z -= JumpCrouchHeight;

	const float size = GenerationStepSize * 0.5f;
	Vector mins = Vector( -size, -size, 0 );
	Vector maxs = Vector( size, size, JumpCrouchHeight + 10.0f );

	bool wasBlocked = m_isBlocked;

	// See if spot is valid
	trace_t tr;
	UTIL_TraceHull(
		origin,
		origin,
		mins,
		maxs,
		MASK_PLAYERSOLID_BRUSHONLY,
		ignore,
		COLLISION_GROUP_PLAYER_MOVEMENT,
		&tr );

	// If the center is open space, we're effectively blocked
	m_isBlocked = !tr.startsolid;

	if ( wasBlocked != m_isBlocked )
	{
		IGameEvent * event = gameeventmanager->CreateEvent( "nav_blocked" );
		if ( event )
		{
			event->SetInt( "area", m_id );
			event->SetInt( "blocked", m_isBlocked );
			gameeventmanager->FireEvent( event );
		}
	}

	/*
	if ( m_isBlocked )
	{
		NDebugOverlay::Box( origin, mins, maxs, 255, 0, 0, 64, 3.0f );
	}
	else
	{
		NDebugOverlay::Box( origin, mins, maxs, 0, 255, 0, 64, 3.0f );
	}
	*/
}


//--------------------------------------------------------------------------------------------------------------
void CNavArea::CheckWaterLevel( void )
{
	Vector pos( GetCenter() );
	if ( !TheNavMesh->GetGroundHeight( pos, &pos.z ) )
	{
		m_isUnderwater = false;
		return;
	}

	pos.z += 1;
	m_isUnderwater = (enginetrace->GetPointContents( pos ) & MASK_WATER) != 0;
}


//--------------------------------------------------------------------------------------------------------------
static void CommandNavCheckFloor( void )
{
	if ( !UTIL_IsCommandIssuedByServerAdmin() )
		return;

	if ( TheNavMesh->GetMarkedArea() )
	{
		CNavArea *area = TheNavMesh->GetMarkedArea();
		area->CheckFloor( NULL );
		if ( area->IsBlocked() )
		{
			DevMsg( "Area #%d %s is blocked\n", area->GetID(), VecToString( area->GetCenter() + Vector( 0, 0, HalfHumanHeight ) ) );
		}
	}
	else
	{
		float start = engine->Time();
		FOR_EACH_LL( TheNavAreaList, nit )
		{
			CNavArea *area = TheNavAreaList[ nit ];
			area->CheckFloor( NULL );
			if ( area->IsBlocked() )
			{
				DevMsg( "Area #%d %s is blocked\n", area->GetID(), VecToString( area->GetCenter() + Vector( 0, 0, HalfHumanHeight ) ) );
			}
		}

		float end = engine->Time();
		float time = (end - start) * 1000.0f;
		DevMsg( "nav_check_floor took %2.2f ms\n", time );
	}
}
static ConCommand nav_check_floor( "nav_check_floor", CommandNavCheckFloor, "Updates the blocked/unblocked status for every nav area.", FCVAR_GAMEDLL );


//--------------------------------------------------------------------------------------------------------------