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diff --git a/game/server/nav_area.cpp b/game/server/nav_area.cpp
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--- /dev/null
+++ b/game/server/nav_area.cpp
@@ -0,0 +1,5880 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//
+//=============================================================================//
+// nav_area.cpp
+// AI Navigation areas
+// Author: Michael S. Booth ([email protected]), January 2003
+
+#include "cbase.h"
+
+#include "tier0/vprof.h"
+#include "tier0/tslist.h"
+#include "tier1/utlhash.h"
+#include "vstdlib/jobthread.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"
+
+#ifdef TERROR
+#include "func_elevator.h"
+#include "AmbientLight.h"
+#endif
+
+#include "Color.h"
+#include "collisionutils.h"
+#include "functorutils.h"
+#include "team.h"
+#include "nav_entities.h"
+
+// memdbgon must be the last include file in a .cpp file!!!
+#include "tier0/memdbgon.h"
+
+extern void HintMessageToAllPlayers( const char *message );
+
+unsigned int CNavArea::m_nextID = 1;
+NavAreaVector TheNavAreas;
+
+unsigned int CNavArea::m_masterMarker = 1;
+CNavArea *CNavArea::m_openList = NULL;
+CNavArea *CNavArea::m_openListTail = NULL;
+
+bool CNavArea::m_isReset = false;
+uint32 CNavArea::s_nCurrVisTestCounter = 0;
+
+ConVar nav_coplanar_slope_limit( "nav_coplanar_slope_limit", "0.99", FCVAR_CHEAT );
+ConVar nav_coplanar_slope_limit_displacement( "nav_coplanar_slope_limit_displacement", "0.7", FCVAR_CHEAT );
+ConVar nav_split_place_on_ground( "nav_split_place_on_ground", "0", FCVAR_CHEAT, "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_CHEAT, "RGBA color to draw as the background color for nav areas while editing." );
+ConVar nav_corner_adjust_adjacent( "nav_corner_adjust_adjacent", "18", FCVAR_CHEAT, "radius used to raise/lower corners in nearby areas when raising/lowering corners." );
+ConVar nav_show_light_intensity( "nav_show_light_intensity", "0", FCVAR_CHEAT );
+ConVar nav_debug_blocked( "nav_debug_blocked", "0", FCVAR_CHEAT );
+ConVar nav_show_contiguous( "nav_show_continguous", "0", FCVAR_CHEAT, "Highlight non-contiguous connections" );
+
+const float DEF_NAV_VIEW_DISTANCE = 1500.0;
+ConVar nav_max_view_distance( "nav_max_view_distance", "6000", FCVAR_CHEAT, "Maximum range for precomputed nav mesh visibility (0 = default 1500 units)" );
+ConVar nav_update_visibility_on_edit( "nav_update_visibility_on_edit", "0", FCVAR_CHEAT, "If nonzero editing the mesh will incrementally recompue visibility" );
+ConVar nav_potentially_visible_dot_tolerance( "nav_potentially_visible_dot_tolerance", "0.98", FCVAR_CHEAT );
+ConVar nav_show_potentially_visible( "nav_show_potentially_visible", "0", FCVAR_CHEAT, "Show areas that are potentially visible from the current nav area" );
+
+Color s_selectedSetColor( 255, 255, 200, 96 );
+Color s_selectedSetBorderColor( 100, 100, 0, 255 );
+Color s_dragSelectionSetBorderColor( 50, 50, 50, 255 );
+static void SelectedSetColorChaged( IConVar *var, const char *pOldValue, float flOldValue )
+{
+	ConVarRef colorVar( var->GetName() );
+
+	Color *color = &s_selectedSetColor;
+	if ( FStrEq( var->GetName(), "nav_selected_set_border_color" ) )
+	{
+		color = &s_selectedSetBorderColor;
+	}
+
+	// Xbox compiler needs these to be in this explicit form
+	// likely due to sscanf expecting word aligned boundaries
+	int r = color->r();
+	int g = color->r();
+	int b = color->b();
+	int a = color->a();
+	int numFound = sscanf( colorVar.GetString(), "%d %d %d %d", &r, &g, &b, &a );
+
+	(*color)[0] = r;
+	(*color)[1] = g;
+	(*color)[2] = b;
+	if ( numFound > 3 )
+	{
+		(*color)[3] = a;
+	}
+}
+ConVar nav_selected_set_color( "nav_selected_set_color", "255 255 200 96", FCVAR_CHEAT, "Color used to draw the selected set background while editing.", false, 0.0f, false, 0.0f, SelectedSetColorChaged );
+ConVar nav_selected_set_border_color( "nav_selected_set_border_color", "100 100 0 255", FCVAR_CHEAT, "Color used to draw the selected set borders while editing.", false, 0.0f, false, 0.0f, SelectedSetColorChaged );
+
+//--------------------------------------------------------------------------------------------------------------
+
+CMemoryStack CNavVectorNoEditAllocator::m_memory;
+void *CNavVectorNoEditAllocator::m_pCurrent;
+int CNavVectorNoEditAllocator::m_nBytesCurrent;
+
+CNavVectorNoEditAllocator::CNavVectorNoEditAllocator()
+{
+	m_pCurrent = NULL;
+	m_nBytesCurrent = 0;
+}
+
+void CNavVectorNoEditAllocator::Reset()
+{
+	m_memory.FreeAll();
+	m_pCurrent = NULL;
+	m_nBytesCurrent = 0;
+}
+
+void *CNavVectorNoEditAllocator::Alloc( size_t nSize )
+{
+	if ( !m_memory.GetBase() )
+	{
+		m_memory.Init( 1024*1024, 0, 0, 4 );
+	}
+	m_pCurrent = (int *)m_memory.Alloc( nSize );
+	m_nBytesCurrent = nSize;
+	return m_pCurrent;
+}
+
+void *CNavVectorNoEditAllocator::Realloc( void *pMem, size_t nSize )
+{
+	if ( pMem != m_pCurrent )
+	{
+		Assert( 0 );
+		Error( "Nav mesh cannot be mutated after load\n" );
+	}
+	if ( nSize > (size_t)m_nBytesCurrent )
+	{
+		m_memory.Alloc( nSize - m_nBytesCurrent );
+		m_nBytesCurrent = nSize;
+	}
+	return m_pCurrent;
+}
+
+void CNavVectorNoEditAllocator::Free( void *pMem )
+{
+}
+
+size_t CNavVectorNoEditAllocator::GetSize( void *pMem )
+{
+	if ( pMem != m_pCurrent )
+	{
+		Assert( 0 );
+		Error( "Nav mesh cannot be mutated after load\n" );
+	}
+	return m_nBytesCurrent;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavArea::CompressIDs( void )
+{
+	m_nextID = 1;
+
+	FOR_EACH_VEC( TheNavAreas, id )
+	{
+		CNavArea *area = TheNavAreas[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 );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Constructor used during normal runtime.
+ */
+CNavArea::CNavArea( void )
+{
+	m_marker = 0;
+	m_nearNavSearchMarker = 0;
+	m_damagingTickCount = 0;
+	m_openMarker = 0;
+
+	m_parent = NULL;
+	m_parentHow = GO_NORTH;
+	m_attributeFlags = 0;
+	m_place = TheNavMesh->GetNavPlace();
+	m_isUnderwater = false;
+	m_avoidanceObstacleHeight = 0.0f;
+
+	m_totalCost = 0.0f;
+	m_costSoFar = 0.0f;
+	m_pathLengthSoFar = 0.0f;
+
+	ResetNodes();
+
+	int i;
+	for ( i=0; i<MAX_NAV_TEAMS; ++i )
+	{
+		m_isBlocked[i] = false;
+
+		m_danger[i] = 0.0f;
+		m_dangerTimestamp[i] = 0.0f;
+
+		m_clearedTimestamp[i] = 0.0f;
+
+		m_earliestOccupyTime[i] = 0.0f;
+	
+		m_playerCount[i] = 0;
+	}
+
+	// set an ID for splitting and other interactive editing - loads will overwrite this
+	m_id = m_nextID++;
+	m_debugid = 0;
+
+	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();
+	}
+
+	for ( i=0; i<NUM_CORNERS; ++i )
+	{
+		m_lightIntensity[i] = 1.0f;
+	}
+
+	m_elevator = NULL;
+	m_elevatorAreas.RemoveAll();
+
+	m_invDxCorners = 0;
+	m_invDyCorners = 0;
+
+	m_inheritVisibilityFrom.area = NULL;
+	m_isInheritedFrom = false;
+
+	m_funcNavCostVector.RemoveAll();
+
+	m_nVisTestCounter = (uint32)-1;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Assumes Z is flat
+ */
+void CNavArea::Build( const Vector &corner, const Vector &otherCorner )
+{
+	if (corner.x < otherCorner.x)
+	{
+		m_nwCorner.x = corner.x;
+		m_seCorner.x = otherCorner.x;
+	}
+	else
+	{
+		m_seCorner.x = corner.x;
+		m_nwCorner.x = otherCorner.x;
+	}
+
+	if (corner.y < otherCorner.y)
+	{
+		m_nwCorner.y = corner.y;
+		m_seCorner.y = otherCorner.y;
+	}
+	else
+	{
+		m_seCorner.y = corner.y;
+		m_nwCorner.y = otherCorner.y;
+	}
+
+	m_nwCorner.z = corner.z;
+	m_seCorner.z = corner.z;
+
+	m_center.x = (m_nwCorner.x + m_seCorner.x)/2.0f;
+	m_center.y = (m_nwCorner.y + m_seCorner.y)/2.0f;
+	m_center.z = (m_nwCorner.z + m_seCorner.z)/2.0f;
+
+	if ( ( m_seCorner.x - m_nwCorner.x ) > 0.0f && ( m_seCorner.y - m_nwCorner.y ) > 0.0f )
+	{
+		m_invDxCorners = 1.0f / ( m_seCorner.x - m_nwCorner.x );
+		m_invDyCorners = 1.0f / ( m_seCorner.y - m_nwCorner.y );
+	}
+	else
+	{
+		m_invDxCorners = m_invDyCorners = 0;
+	}
+
+	m_neZ = corner.z;
+	m_swZ = otherCorner.z;
+
+	CalcDebugID();
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Build a nav area given the positions of its four corners.
+ */
+void CNavArea::Build( const Vector &nwCorner, const Vector &neCorner, const Vector &seCorner, const Vector &swCorner )
+{
+	m_nwCorner = nwCorner;
+	m_seCorner = seCorner;
+
+	m_center.x = (m_nwCorner.x + m_seCorner.x)/2.0f;
+	m_center.y = (m_nwCorner.y + m_seCorner.y)/2.0f;
+	m_center.z = (m_nwCorner.z + m_seCorner.z)/2.0f;
+
+	m_neZ = neCorner.z;
+	m_swZ = swCorner.z;
+
+	if ( ( m_seCorner.x - m_nwCorner.x ) > 0.0f && ( m_seCorner.y - m_nwCorner.y ) > 0.0f )
+	{
+		m_invDxCorners = 1.0f / ( m_seCorner.x - m_nwCorner.x );
+		m_invDyCorners = 1.0f / ( m_seCorner.y - m_nwCorner.y );
+	}
+	else
+	{
+		m_invDxCorners = m_invDyCorners = 0;
+	}
+
+	CalcDebugID();
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Used during generation phase to build nav areas from sampled nodes.
+ */
+void CNavArea::Build( CNavNode *nwNode, CNavNode *neNode, CNavNode *seNode, CNavNode *swNode )
+{
+	m_nwCorner = *nwNode->GetPosition();
+	m_seCorner = *seNode->GetPosition();
+
+	m_center.x = (m_nwCorner.x + m_seCorner.x)/2.0f;
+	m_center.y = (m_nwCorner.y + m_seCorner.y)/2.0f;
+	m_center.z = (m_nwCorner.z + m_seCorner.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;
+
+	if ( ( m_seCorner.x - m_nwCorner.x ) > 0.0f && ( m_seCorner.y - m_nwCorner.y ) > 0.0f )
+	{
+		m_invDxCorners = 1.0f / ( m_seCorner.x - m_nwCorner.x );
+		m_invDyCorners = 1.0f / ( m_seCorner.y - m_nwCorner.y );
+	}
+	else
+	{
+		m_invDxCorners = m_invDyCorners = 0;
+	}
+
+	// mark internal nodes as part of this area
+	AssignNodes( this );
+
+	CalcDebugID();
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+// Return a computed extent (XY is in m_nwCorner and m_seCorner, Z is computed)
+void CNavArea::GetExtent( Extent *extent ) const
+{
+	extent->lo = m_nwCorner;
+	extent->hi = m_seCorner;
+
+	extent->lo.z = MIN( extent->lo.z, m_nwCorner.z );
+	extent->lo.z = MIN( extent->lo.z, m_seCorner.z );
+	extent->lo.z = MIN( extent->lo.z, m_neZ );
+	extent->lo.z = MIN( extent->lo.z, m_swZ );
+
+	extent->hi.z = MAX( extent->hi.z, m_nwCorner.z );
+	extent->hi.z = MAX( extent->hi.z, m_seCorner.z );
+	extent->hi.z = MAX( extent->hi.z, m_neZ );
+	extent->hi.z = MAX( extent->hi.z, m_swZ );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+// returns the closest node along the given edge to the given point
+CNavNode *CNavArea::FindClosestNode( const Vector &pos, NavDirType dir ) const
+{
+	if ( !HasNodes() )
+		return NULL;
+
+	CUtlVector< CNavNode * > nodes;
+	GetNodes( dir, &nodes );
+
+	CNavNode *bestNode = NULL;
+	float bestDistanceSq = FLT_MAX;
+
+	for ( int i=0; i<nodes.Count(); ++i )
+	{
+		float distSq = pos.DistToSqr( *nodes[i]->GetPosition() );
+		if ( distSq < bestDistanceSq )
+		{
+			bestDistanceSq = distSq;
+			bestNode = nodes[i];
+		}
+	}
+
+	return bestNode;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+// build a vector of nodes along the given direction
+void CNavArea::GetNodes( NavDirType dir, CUtlVector< CNavNode * > *nodes ) const
+{
+	if ( !nodes )
+		return;
+
+	nodes->RemoveAll();
+
+	NavCornerType startCorner;
+	NavCornerType endCorner;
+	NavDirType traversalDirection;
+
+	switch ( dir )
+	{
+	case NORTH:
+		startCorner = NORTH_WEST;
+		endCorner = NORTH_EAST;
+		traversalDirection = EAST;
+		break;
+
+	case SOUTH:
+		startCorner = SOUTH_WEST;
+		endCorner = SOUTH_EAST;
+		traversalDirection = EAST;
+		break;
+
+	case EAST:
+		startCorner = NORTH_EAST;
+		endCorner = SOUTH_EAST;
+		traversalDirection = SOUTH;
+		break;
+
+	case WEST:
+		startCorner = NORTH_WEST;
+		endCorner = SOUTH_WEST;
+		traversalDirection = SOUTH;
+		break;
+
+	default:
+		return;
+	}
+
+	CNavNode *node;
+	for ( node = m_node[ startCorner ]; node && node != m_node[ endCorner ]; node = node->GetConnectedNode( traversalDirection ) )
+	{
+		nodes->AddToTail( node );
+	}
+	if ( node && node == m_node[ endCorner ] )
+	{
+		nodes->AddToTail( node );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+class ForgetArea
+{
+public:
+	ForgetArea( CNavArea *area )
+	{
+		m_area = area;
+	}
+	
+	bool operator() ( CBasePlayer *player )
+	{
+		player->OnNavAreaRemoved( m_area );
+		
+		return true;
+	}
+
+	bool operator() ( CBaseCombatCharacter *player )
+	{
+		player->OnNavAreaRemoved( m_area );
+
+		return true;
+	}
+
+	CNavArea *m_area;
+};
+
+
+//--------------------------------------------------------------------------------------------------------------
+class AreaDestroyNotification
+{
+	CNavArea *m_area;
+
+public:
+	AreaDestroyNotification( CNavArea *area )
+	{
+		m_area = area;
+	}
+
+	bool operator()( CNavLadder *ladder )
+	{
+		ladder->OnDestroyNotify( m_area );
+		return true;
+	}
+
+	bool operator()( CNavArea *area )
+	{
+		if ( area != m_area )
+		{
+			area->OnDestroyNotify( m_area );
+		}
+		return true;
+	}
+};
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Destructor
+ */
+CNavArea::~CNavArea()
+{
+	// spot encounters aren't owned by anything else, so free them up here
+	m_spotEncounters.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 and ladders we are going away
+	AreaDestroyNotification notification( this );
+	TheNavMesh->ForAllAreas( notification );
+	TheNavMesh->ForAllLadders( notification );
+
+	// remove the area from the grid
+	TheNavMesh->RemoveNavArea( this );
+	
+	// make sure no players keep a pointer to this area
+	ForgetArea forget( this );
+	ForEachActor( forget );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Find elevator connections between areas
+ */
+void CNavArea::ConnectElevators( void )
+{
+	m_elevator = NULL;
+	m_attributeFlags &= ~NAV_MESH_HAS_ELEVATOR;
+	m_elevatorAreas.RemoveAll();
+
+#ifdef TERROR
+	// connect elevators
+	CFuncElevator *elevator = NULL;
+	while( ( elevator = (CFuncElevator *)gEntList.FindEntityByClassname( elevator, "func_elevator" ) ) != NULL )
+	{
+		if ( elevator->GetNumFloors() < 2 )
+		{
+			// broken elevator
+			continue;
+		}
+
+		Extent elevatorExtent;
+		elevator->CollisionProp()->WorldSpaceSurroundingBounds( &elevatorExtent.lo, &elevatorExtent.hi );
+
+		if ( IsOverlapping( elevatorExtent ) )
+		{
+			// overlaps in 2D - check that this area is within the shaft of the elevator
+			const Vector &center = GetCenter();
+
+			for( int f=0; f<elevator->GetNumFloors(); ++f ) 
+			{
+				const FloorInfo	*floor = elevator->GetFloor( f );
+				const float tolerance = 30.0f;
+
+				if ( center.z <= floor->height + tolerance && center.z >= floor->height - tolerance )
+				{
+					if ( m_elevator )
+					{
+						Warning( "Multiple elevators overlap navigation area #%d\n", GetID() );
+						break;
+					}
+
+					// this area is part of an elevator system
+					m_elevator = elevator;
+					m_attributeFlags |= NAV_MESH_HAS_ELEVATOR;
+
+					// find the largest area overlapping this elevator on each other floor 
+					for( int of=0; of<elevator->GetNumFloors(); ++of ) 
+					{
+						if ( of == f )
+						{
+							// we are on this floor
+							continue;
+						}
+
+						const FloorInfo	*otherFloor = elevator->GetFloor( of );
+
+						// find the largest area at this floor
+						CNavArea *floorArea = NULL;
+						float floorAreaSize = 0.0f;
+
+						FOR_EACH_VEC( TheNavAreas, it )
+						{
+							CNavArea *area = TheNavAreas[ it ];
+
+							if ( area->IsOverlapping( elevatorExtent ) )
+							{
+								if ( area->GetCenter().z <= otherFloor->height + tolerance && area->GetCenter().z >= otherFloor->height - tolerance )
+								{
+									float size = area->GetSizeX() * area->GetSizeY();
+									if ( size > floorAreaSize )
+									{
+										floorArea = area;
+										floorAreaSize = size;
+									}
+								}
+							}
+						}
+
+						if ( floorArea )
+						{
+							// add this area to the set of areas reachable via elevator
+							NavConnect con;
+							con.area = floorArea;
+							con.length = ( floorArea->GetCenter() - GetCenter() ).Length();
+							m_elevatorAreas.AddToTail( con );
+						}
+						else
+						{
+							Warning( "Floor %d ('%s') of elevator at ( %3.2f, %3.2f, %3.2f ) has no matching navigation areas\n", 
+									 of, 
+									 otherFloor->name.ToCStr(),
+									 elevator->GetAbsOrigin().x, elevator->GetAbsOrigin().y, elevator->GetAbsOrigin().z );
+						}
+					}
+
+					// we found our floor
+					break;
+				}
+			}
+		}
+	}
+#endif // TERROR
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Invoked when map is initially loaded
+ */
+void CNavArea::OnServerActivate( void )
+{
+	ConnectElevators();
+	m_damagingTickCount = 0;
+	ClearAllNavCostEntities();
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Invoked for each area when the round restarts
+ */
+void CNavArea::OnRoundRestart( void )
+{
+	// need to redo this here since func_elevators are deleted and recreated at round restart
+	ConnectElevators();
+	m_damagingTickCount = 0;
+	ClearAllNavCostEntities();
+}
+
+
+#ifdef DEBUG_AREA_PLAYERCOUNTS
+//--------------------------------------------------------------------------------------------------------------
+void CNavArea::IncrementPlayerCount( int teamID, int entIndex )
+{
+	ConColorMsg( Color( 128, 255, 128, 255 ), "%f: Adding ent %d (team %d) to area %d\n", gpGlobals->curtime, entIndex, teamID, GetID() );
+	teamID = teamID % MAX_NAV_TEAMS;
+	Assert( !m_playerEntIndices[teamID].HasElement( entIndex ) );
+	if ( !m_playerEntIndices[teamID].HasElement( entIndex ) )
+	{
+		m_playerEntIndices[teamID].AddToTail( entIndex );
+	}
+
+	if (m_playerCount[ teamID ] == 255)
+	{
+		Warning( "CNavArea::IncrementPlayerCount: Overflow\n" );
+		return;
+	}
+
+	++m_playerCount[ teamID ];
+}
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavArea::DecrementPlayerCount( int teamID, int entIndex )
+{
+	ConColorMsg( Color( 128, 128, 255, 255 ), "%f: Removing ent %d (team %d) from area %d\n", gpGlobals->curtime, entIndex, teamID, GetID() );
+	teamID = teamID % MAX_NAV_TEAMS;
+	Assert( m_playerEntIndices[teamID].HasElement( entIndex ) );
+	m_playerEntIndices[teamID].FindAndFastRemove( entIndex );
+
+	if (m_playerCount[ teamID ] == 0)
+	{
+		Warning( "CNavArea::IncrementPlayerCount: Underflow\n" );
+		return;
+	}
+
+	--m_playerCount[ teamID ];
+}
+#endif // DEBUG_AREA_PLAYERCOUNTS
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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_incomingConnect[ d ].FindAndRemove( con );
+	}
+
+	// remove all visibility info, since we're editing the mesh anyways
+	m_inheritVisibilityFrom.area = NULL;
+	m_potentiallyVisibleAreas.RemoveAll();
+	m_isInheritedFrom = false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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_VEC( m_connect[ dir ], it )
+	{
+		if (m_connect[ dir ][ it ].area == area)
+			return;
+	}
+
+	NavConnect con;
+	con.area = area;
+	con.length = ( area->GetCenter() - GetCenter() ).Length();
+	m_connect[ dir ].AddToTail( con );
+	m_incomingConnect[ dir ].FindAndRemove( con );
+
+	NavDirType dirOpposite = OppositeDirection( dir );
+	con.area = this;
+	if ( area->m_connect[ dirOpposite ].Find( con ) == area->m_connect[ dirOpposite ].InvalidIndex() )
+	{
+		area->AddIncomingConnection( this, dirOpposite );
+	}	
+	
+	//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 i = 0; i<NUM_DIRECTIONS; i++ )
+	{
+		NavDirType dir = (NavDirType) i;
+		NavDirType dirOpposite = OppositeDirection( dir );
+		int index = m_connect[ dir ].Find( connect );
+		if ( index != m_connect[ dir ].InvalidIndex() )
+		{
+			m_connect[ dir ].Remove( index );
+			if ( area->IsConnected( this, dirOpposite ) )
+			{
+				AddIncomingConnection( area, dir );
+			}
+			else
+			{
+				connect.area = this;
+				area->m_incomingConnect[ dirOpposite ].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_nwCorner = *m_node[ NORTH_WEST ]->GetPosition();
+	m_seCorner = *m_node[ SOUTH_EAST ]->GetPosition();
+
+	m_center.x = (m_nwCorner.x + m_seCorner.x)/2.0f;
+	m_center.y = (m_nwCorner.y + m_seCorner.y)/2.0f;
+	m_center.z = (m_nwCorner.z + m_seCorner.z)/2.0f;
+
+	m_neZ = m_node[ NORTH_EAST ]->GetPosition()->z;
+	m_swZ = m_node[ SOUTH_WEST ]->GetPosition()->z;
+
+	if ( ( m_seCorner.x - m_nwCorner.x ) > 0.0f && ( m_seCorner.y - m_nwCorner.y ) > 0.0f )
+	{
+		m_invDxCorners = 1.0f / ( m_seCorner.x - m_nwCorner.x );
+		m_invDyCorners = 1.0f / ( m_seCorner.y - m_nwCorner.y );
+	}
+	else
+	{
+		m_invDxCorners = m_invDyCorners = 0;
+	}
+
+	// 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
+	TheNavAreas.FindAndRemove( adjArea );
+	TheNavMesh->OnEditDestroyNotify( adjArea );
+	TheNavMesh->DestroyArea( adjArea );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+class LadderConnectionReplacement
+{
+	CNavArea *m_originalArea;
+	CNavArea *m_replacementArea;
+
+public:
+	LadderConnectionReplacement( CNavArea *originalArea, CNavArea *replacementArea )
+	{
+		m_originalArea = originalArea;
+		m_replacementArea = replacementArea;
+	}
+
+	bool operator()( CNavLadder *ladder )
+	{
+		if ( ladder->m_topForwardArea == m_originalArea )
+			ladder->m_topForwardArea = m_replacementArea;
+
+		if ( ladder->m_topRightArea == m_originalArea )
+			ladder->m_topRightArea = m_replacementArea;
+
+		if ( ladder->m_topLeftArea == m_originalArea )
+			ladder->m_topLeftArea = m_replacementArea;
+
+		if ( ladder->m_topBehindArea == m_originalArea )
+			ladder->m_topBehindArea = m_replacementArea;
+
+		if ( ladder->m_bottomArea == m_originalArea )
+			ladder->m_bottomArea = m_replacementArea;
+
+		return true;
+	}
+};
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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_VEC( 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
+	Disconnect( adjArea );
+	
+	// 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_VEC( TheNavAreas, it )
+	{
+		CNavArea *area = TheNavAreas[ 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_VEC( 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
+				area->Disconnect( adjArea );
+
+				// remove all references to the new area
+				area->Disconnect( this );
+
+				// add a single connection to the new area
+				area->ConnectTo( this, (NavDirType) dir );
+			}
+		}
+	}
+
+	// We gain all ladder connections adjArea had
+	for( dir=0; dir<CNavLadder::NUM_LADDER_DIRECTIONS; ++dir )
+	{
+		FOR_EACH_VEC( adjArea->m_ladder[ dir ], it )
+		{
+			ConnectTo( adjArea->m_ladder[ dir ][ it ].ladder );
+		}
+	}
+
+	// All ladders that point to adjArea should point to us now
+	LadderConnectionReplacement replacement( adjArea, this );
+	TheNavMesh->ForAllLadders( replacement );
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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 );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+class SplitNotification
+{
+	CNavArea *m_originalArea;
+	CNavArea *m_alphaArea;
+	CNavArea *m_betaArea;
+
+public:
+	SplitNotification( CNavArea *originalArea, CNavArea *alphaArea, CNavArea *betaArea )
+	{
+		m_originalArea = originalArea;
+		m_alphaArea = alphaArea;
+		m_betaArea = betaArea;
+	}
+
+	bool operator()( CNavLadder *ladder )
+	{
+		ladder->OnSplit( m_originalArea, m_alphaArea, m_betaArea );
+		return true;
+	}
+};
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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_nwCorner.y + 1.0f)
+			return false;
+
+		if (splitEdge >= m_seCorner.y - 1.0f)
+			return false;
+
+		alpha = TheNavMesh->CreateArea();
+		alpha->m_nwCorner = m_nwCorner;
+
+		alpha->m_seCorner.x = m_seCorner.x;
+		alpha->m_seCorner.y = splitEdge;
+		alpha->m_seCorner.z = GetZ( alpha->m_seCorner );
+
+		beta = TheNavMesh->CreateArea();
+		beta->m_nwCorner.x = m_nwCorner.x;
+		beta->m_nwCorner.y = splitEdge;
+		beta->m_nwCorner.z = GetZ( beta->m_nwCorner );
+
+		beta->m_seCorner = m_seCorner;
+
+		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_nwCorner.x + 1.0f)
+			return false;
+
+		if (splitEdge >= m_seCorner.x - 1.0f)
+			return false;
+
+		alpha = TheNavMesh->CreateArea();
+		alpha->m_nwCorner = m_nwCorner;
+
+		alpha->m_seCorner.x = splitEdge;
+		alpha->m_seCorner.y = m_seCorner.y;
+		alpha->m_seCorner.z = GetZ( alpha->m_seCorner );
+
+		beta = TheNavMesh->CreateArea();
+		beta->m_nwCorner.x = splitEdge;
+		beta->m_nwCorner.y = m_nwCorner.y;
+		beta->m_nwCorner.z = GetZ( beta->m_nwCorner );
+
+		beta->m_seCorner = m_seCorner;
+
+		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_VEC( 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
+	SplitNotification notify( this, alpha, beta );
+	TheNavMesh->ForAllLadders( notify );
+
+	// return new areas
+	if (outAlpha)
+		*outAlpha = alpha;
+
+	if (outBeta)
+		*outBeta = beta;
+
+	TheNavMesh->OnEditCreateNotify( alpha );
+	TheNavMesh->OnEditCreateNotify( beta );
+	if ( TheNavMesh->IsInSelectedSet( this ) )
+	{
+		TheNavMesh->AddToSelectedSet( alpha );
+		TheNavMesh->AddToSelectedSet( beta );
+	}
+
+	// remove original area
+	TheNavMesh->OnEditDestroyNotify( this );
+	TheNavAreas.FindAndRemove( this );
+	TheNavMesh->RemoveFromSelectedSet( this );
+	TheNavMesh->DestroyArea( 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_VEC( 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_VEC( m_connect[ d ], it )
+			{
+				if (area == m_connect[ d ][ it ].area)
+					return true;
+			}
+		}
+
+		// check ladder connections
+		FOR_EACH_VEC( 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_VEC( 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_VEC( m_connect[ dir ], it )
+		{
+			if (area == m_connect[ dir ][ it ].area)
+				return true;
+		}
+	}
+
+	return false;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Compute change in actual ground height from this area to given area
+ */
+float CNavArea::ComputeGroundHeightChange( const CNavArea *area )
+{
+	VPROF_BUDGET( "CNavArea::ComputeHeightChange", "NextBot" );
+
+	Vector closeFrom, closeTo;
+	area->GetClosestPointOnArea( GetCenter(), &closeTo );
+	GetClosestPointOnArea( area->GetCenter(), &closeFrom );
+
+	// find actual ground height at each point in case 
+	// areas are below/above actual terrain
+	float toZ, fromZ;
+	if ( TheNavMesh->GetSimpleGroundHeight( closeTo + Vector( 0, 0, StepHeight ), &toZ ) == false )
+	{
+		return 0.0f;
+	}
+
+	if ( TheNavMesh->GetSimpleGroundHeight( closeFrom + Vector( 0, 0, StepHeight ), &fromZ ) == false )
+	{
+		return 0.0f;
+	}
+
+	return toZ - fromZ;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * The area 'source' is connected to us along our 'incomingEdgeDir' edge
+ */
+void CNavArea::AddIncomingConnection( CNavArea *source, NavDirType incomingEdgeDir )
+{
+	NavConnect con;
+	con.area = source;
+	if ( m_incomingConnect[ incomingEdgeDir ].Find( con ) == m_incomingConnect[ incomingEdgeDir ].InvalidIndex() )
+	{
+		con.length = ( source->GetCenter() - GetCenter() ).Length();
+		m_incomingConnect[ incomingEdgeDir ].AddToTail( con );
+	}	
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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->InheritAttributes( this );
+
+	newArea->m_center.x = (newArea->m_nwCorner.x + newArea->m_seCorner.x)/2.0f;
+	newArea->m_center.y = (newArea->m_nwCorner.y + newArea->m_seCorner.y)/2.0f;
+	newArea->m_center.z = (newArea->m_nwCorner.z + newArea->m_seCorner.z)/2.0f;
+
+	newArea->m_neZ = GetZ( newArea->m_seCorner.x, newArea->m_nwCorner.y );
+	newArea->m_swZ = GetZ( newArea->m_nwCorner.x, newArea->m_seCorner.y );
+
+	if ( ( m_seCorner.x - m_nwCorner.x ) > 0.0f && ( m_seCorner.y - m_nwCorner.y ) > 0.0f )
+	{
+		newArea->m_invDxCorners = 1.0f / ( newArea->m_seCorner.x - newArea->m_nwCorner.x );
+		newArea->m_invDyCorners = 1.0f / ( newArea->m_seCorner.y - newArea->m_nwCorner.y );
+	}
+	else
+	{
+		newArea->m_invDxCorners = newArea->m_invDyCorners = 0;
+	}
+
+	// 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;
+			}
+
+			for ( int a = 0; a < m_incomingConnect[d].Count(); a++ )
+			{			
+				CNavArea *adj = m_incomingConnect[d][a].area;
+
+				switch( d )
+				{
+				case NORTH:
+				case SOUTH:
+					if (newArea->IsOverlappingX( adj ))
+					{
+						adj->ConnectTo( newArea, OppositeDirection( (NavDirType)d ) );
+					}
+					break;
+
+				case EAST:
+				case WEST:
+					if (newArea->IsOverlappingY( adj ))
+					{
+						adj->ConnectTo( newArea, OppositeDirection( (NavDirType)d ) );
+					}
+					break;
+				}
+			}			
+		}
+	}
+
+	TheNavAreas.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;
+		}
+
+		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_nwCorner.z	= newArea->m_node[ NORTH_WEST ]->GetPosition()->z;
+		newArea->m_swZ			= newArea->m_node[ SOUTH_WEST ]->GetPosition()->z;
+		newArea->m_seCorner.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_nwCorner.x > other->m_seCorner.x)
+	{
+		// 'this' is east of 'other'
+		float top = MAX( m_nwCorner.y, other->m_nwCorner.y );
+		float bottom = MIN( m_seCorner.y, other->m_seCorner.y );
+
+		nw.x = other->m_seCorner.x;
+		nw.y = top;
+		nw.z = other->GetZ( nw );
+
+		se.x = m_nwCorner.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 = TheNavMesh->CreateArea();
+		if (newArea == NULL)
+		{
+			Warning( "SpliceEdit: Out of memory.\n" );
+			return false;
+		}
+		
+		newArea->Build( nw, ne, se, sw );
+
+		this->ConnectTo( newArea, WEST );
+		newArea->ConnectTo( this, EAST );
+
+		other->ConnectTo( newArea, EAST );
+		newArea->ConnectTo( other, WEST );
+	}
+	else if (m_seCorner.x < other->m_nwCorner.x)
+	{
+		// 'this' is west of 'other'
+		float top = MAX( m_nwCorner.y, other->m_nwCorner.y );
+		float bottom = MIN( m_seCorner.y, other->m_seCorner.y );
+
+		nw.x = m_seCorner.x;
+		nw.y = top;
+		nw.z = GetZ( nw );
+
+		se.x = other->m_nwCorner.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 = TheNavMesh->CreateArea();
+		if (newArea == NULL)
+		{
+			Warning( "SpliceEdit: Out of memory.\n" );
+			return false;
+		}
+		
+		newArea->Build( 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_nwCorner.y > other->m_seCorner.y)
+		{
+			// 'this' is south of 'other'
+			float left = MAX( m_nwCorner.x, other->m_nwCorner.x );
+			float right = MIN( m_seCorner.x, other->m_seCorner.x );
+
+			nw.x = left;
+			nw.y = other->m_seCorner.y;
+			nw.z = other->GetZ( nw );
+
+			se.x = right;
+			se.y = m_nwCorner.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 = TheNavMesh->CreateArea();
+			if (newArea == NULL)
+			{
+				Warning( "SpliceEdit: Out of memory.\n" );
+				return false;
+			}
+			
+			newArea->Build( nw, ne, se, sw );
+
+			this->ConnectTo( newArea, NORTH );
+			newArea->ConnectTo( this, SOUTH );
+
+			other->ConnectTo( newArea, SOUTH );
+			newArea->ConnectTo( other, NORTH );
+		}
+		else if (m_seCorner.y < other->m_nwCorner.y)
+		{
+			// 'this' is north of 'other'
+			float left = MAX( m_nwCorner.x, other->m_nwCorner.x );
+			float right = MIN( m_seCorner.x, other->m_seCorner.x );
+
+			nw.x = left;
+			nw.y = m_seCorner.y;
+			nw.z = GetZ( nw );
+
+			se.x = right;
+			se.y = other->m_nwCorner.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 = TheNavMesh->CreateArea();
+			if (newArea == NULL)
+			{
+				Warning( "SpliceEdit: Out of memory.\n" );
+				return false;
+			}
+			
+			newArea->Build( 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;
+		}
+	}
+
+	newArea->InheritAttributes( this, other );
+
+	TheNavAreas.AddToTail( newArea );
+	TheNavMesh->AddNavArea( newArea );
+	
+	TheNavMesh->OnEditCreateNotify( newArea );
+
+	return true;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+* Calculates a constant ID for an area at this location, for debugging
+*/
+void CNavArea::CalcDebugID()
+{
+	if ( m_debugid == 0 )
+	{
+		// calculate a debug ID which will be constant for this nav area across generation runs
+		int coord[6] = { (int) m_nwCorner.x, (int) m_nwCorner.x, (int) m_nwCorner.z, (int) m_seCorner.x, (int) m_seCorner.y, (int) m_seCorner.z };
+		m_debugid = CRC32_ProcessSingleBuffer( &coord, sizeof( coord ) );
+	}
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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_nwCorner.x - adj->m_nwCorner.x ) < tolerance && 
+		fabs( m_seCorner.x - adj->m_seCorner.x ) < tolerance)
+		merge = true;
+
+	if (fabs( m_nwCorner.y - adj->m_nwCorner.y ) < tolerance && 
+		fabs( m_seCorner.y - adj->m_seCorner.y ) < tolerance)
+		merge = true;
+
+	if (merge == false)
+		return false;
+
+	Vector originalNWCorner = m_nwCorner;
+	Vector originalSECorner = m_seCorner;
+	
+	// update extent
+	if (m_nwCorner.x > adj->m_nwCorner.x || m_nwCorner.y > adj->m_nwCorner.y)
+		m_nwCorner = adj->m_nwCorner;
+
+	if (m_seCorner.x < adj->m_seCorner.x || m_seCorner.y < adj->m_seCorner.y)
+		m_seCorner = adj->m_seCorner;
+
+	m_center.x = (m_nwCorner.x + m_seCorner.x)/2.0f;
+	m_center.y = (m_nwCorner.y + m_seCorner.y)/2.0f;
+	m_center.z = (m_nwCorner.z + m_seCorner.z)/2.0f;
+
+	if ( ( m_seCorner.x - m_nwCorner.x ) > 0.0f && ( m_seCorner.y - m_nwCorner.y ) > 0.0f )
+	{
+		m_invDxCorners = 1.0f / ( m_seCorner.x - m_nwCorner.x );
+		m_invDyCorners = 1.0f / ( m_seCorner.y - m_nwCorner.y );
+	}
+	else
+	{
+		m_invDxCorners = m_invDyCorners = 0;
+	}
+
+	if (m_seCorner.x > originalSECorner.x || m_nwCorner.y < originalNWCorner.y)
+		m_neZ = adj->GetZ( m_seCorner.x, m_nwCorner.y );
+	else
+		m_neZ = GetZ( m_seCorner.x, m_nwCorner.y );
+
+	if (m_nwCorner.x < originalNWCorner.x || m_seCorner.y > originalSECorner.y)
+		m_swZ = adj->GetZ( m_nwCorner.x, m_seCorner.y );
+	else
+		m_swZ = GetZ( m_nwCorner.x, m_seCorner.y );
+
+	// merge adjacency links - we gain all the connections that adjArea had
+	MergeAdjacentConnections( adj );
+
+	InheritAttributes( adj );
+
+	// remove subsumed adjacent area
+	TheNavAreas.FindAndRemove( adj );
+	TheNavMesh->OnEditDestroyNotify( adj );
+	TheNavMesh->DestroyArea( adj );
+	
+	TheNavMesh->OnEditCreateNotify( this );
+
+	return true;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavArea::InheritAttributes( CNavArea *first, CNavArea *second )
+{
+	if ( first && second )
+	{
+		SetAttributes( first->GetAttributes() | second->GetAttributes() );
+
+		// if both areas have the same place, the new area inherits it
+		if ( first->GetPlace() == second->GetPlace() )
+		{
+			SetPlace( first->GetPlace() );
+		}
+		else if ( first->GetPlace() == UNDEFINED_PLACE )
+		{
+			SetPlace( second->GetPlace() );
+		}
+		else if ( second->GetPlace() == UNDEFINED_PLACE )
+		{
+			SetPlace( first->GetPlace() );
+		}
+		else
+		{
+			// both have valid, but different places - pick on at random
+			if ( RandomInt( 0, 100 ) < 50 )
+				SetPlace( first->GetPlace() );
+			else
+				SetPlace( second->GetPlace() );
+		}
+	}
+	else if ( first )
+	{
+		SetAttributes( GetAttributes() | first->GetAttributes() );
+		if ( GetPlace() == UNDEFINED_PLACE )
+		{
+			SetPlace( first->GetPlace() );
+		}
+	}
+}
+
+//--------------------------------------------------------------------------------------------------------------
+void ApproachAreaAnalysisPrep( void )
+{
+}
+
+//--------------------------------------------------------------------------------------------------------------
+void CleanupApproachAreaAnalysisPrep( void )
+{
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Remove "analyzed" data from nav area
+ */
+void CNavArea::Strip( void )
+{
+	m_spotEncounters.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_nwCorner.x && pos.x - tolerance <= m_seCorner.x &&
+		pos.y + tolerance >= m_nwCorner.y && pos.y - tolerance <= m_seCorner.y)
+		return true;
+
+	return false;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return true if 'area' overlaps our 2D extents
+ */
+bool CNavArea::IsOverlapping( const CNavArea *area ) const
+{
+	if (area->m_nwCorner.x < m_seCorner.x && area->m_seCorner.x > m_nwCorner.x && 
+		area->m_nwCorner.y < m_seCorner.y && area->m_seCorner.y > m_nwCorner.y)
+		return true;
+
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return true if 'extent' overlaps our 2D extents
+ */
+bool CNavArea::IsOverlapping( const Extent &extent ) const
+{
+	return ( extent.lo.x < m_seCorner.x && extent.hi.x > m_nwCorner.x && 
+			 extent.lo.y < m_seCorner.y && extent.hi.y > m_nwCorner.y );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return true if 'area' overlaps our X extent
+ */
+bool CNavArea::IsOverlappingX( const CNavArea *area ) const
+{
+	if (area->m_nwCorner.x < m_seCorner.x && area->m_seCorner.x > m_nwCorner.x)
+		return true;
+
+	return false;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return true if 'area' overlaps our Y extent
+ */
+bool CNavArea::IsOverlappingY( const CNavArea *area ) const
+{
+	if (area->m_nwCorner.y < m_seCorner.y && area->m_seCorner.y > m_nwCorner.y)
+		return true;
+
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+class COverlapCheck
+{
+public:
+	COverlapCheck( const CNavArea *me, const Vector &pos ) : m_pos( pos )
+	{
+		m_me = me;
+		m_myZ = me->GetZ( pos );
+	}
+
+	bool operator() ( CNavArea *area )
+	{
+		// skip self
+		if ( area == m_me )
+			return true;
+
+		// check 2D overlap
+		if ( !area->IsOverlapping( m_pos ) )
+			return true;
+
+		float theirZ = area->GetZ( m_pos );
+		if ( theirZ > m_pos.z )
+		{
+			// they are above the point
+			return true;
+		}
+
+		if ( theirZ > m_myZ )
+		{
+			// we are below an area that is beneath the given position
+			return false;
+		}
+
+		return true;
+	}
+
+	const CNavArea *m_me;
+	float m_myZ;
+	const Vector &m_pos;
+};
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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
+	// allow nav area to be as much as a step height above the given position
+	if (myZ - StepHeight > pos.z)
+		return false;
+
+	Extent areaExtent;
+	GetExtent( &areaExtent );
+
+	COverlapCheck overlap( this, pos );
+	return TheNavMesh->ForAllAreasOverlappingExtent( overlap, areaExtent );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+* Returns true if area completely contains other area
+*/
+bool CNavArea::Contains( const CNavArea *area ) const
+{
+	return ( ( m_nwCorner.x <= area->m_nwCorner.x ) && ( m_seCorner.x >= area->m_seCorner.x ) &&
+		( m_nwCorner.y <= area->m_nwCorner.y ) && ( m_seCorner.y >= area->m_seCorner.y ) &&
+		( m_nwCorner.z <= area->m_nwCorner.z ) && ( m_seCorner.z >= area->m_seCorner.z ) );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavArea::ComputeNormal( Vector *normal, bool alternate ) const
+{
+	if ( !normal )
+		return;
+
+	Vector u, v;
+
+	if ( !alternate )
+	{
+		u.x = m_seCorner.x - m_nwCorner.x;
+		u.y = 0.0f;
+		u.z = m_neZ - m_nwCorner.z;
+
+		v.x = 0.0f;
+		v.y = m_seCorner.y - m_nwCorner.y;
+		v.z = m_swZ - m_nwCorner.z;
+	}
+	else
+	{
+		u.x = m_nwCorner.x - m_seCorner.x;
+		u.y = 0.0f;
+		u.z = m_swZ - m_seCorner.z;
+
+		v.x = 0.0f;
+		v.y = m_nwCorner.y - m_seCorner.y;
+		v.z = m_neZ - m_seCorner.z;
+	}
+
+	*normal = CrossProduct( u, v );
+	normal->NormalizeInPlace();
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+* Removes all connections in directions to left and right of specified direction
+*/
+void CNavArea::RemoveOrthogonalConnections( NavDirType dir )
+{
+	NavDirType dirToRemove[2];
+	dirToRemove[0] = DirectionLeft( dir );
+	dirToRemove[1] = DirectionRight( dir );
+	for ( int i = 0; i < 2; i++ )
+	{
+		dir = dirToRemove[i];
+		while ( GetAdjacentCount( dir ) > 0 )
+		{
+			CNavArea *adj = GetAdjacentArea( dir, 0 );
+			Disconnect( adj );
+			adj->Disconnect( this );
+		}
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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 );
+
+	float tolerance = nav_coplanar_slope_limit.GetFloat();
+	if ( ( m_node[ NORTH_WEST ] && m_node[ NORTH_WEST ]->IsOnDisplacement() ) ||
+		( m_node[ NORTH_EAST ] && m_node[ NORTH_EAST ]->IsOnDisplacement() ) ||
+		( m_node[ SOUTH_EAST ] && m_node[ SOUTH_EAST ]->IsOnDisplacement() ) ||
+		( m_node[ SOUTH_WEST ] && m_node[ SOUTH_WEST ]->IsOnDisplacement() ) )
+	{
+		tolerance = nav_coplanar_slope_limit_displacement.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;
+
+	bool isOnDisplacement = ( m_node[ NORTH_WEST ] && m_node[ NORTH_WEST ]->IsOnDisplacement() ) ||
+		( m_node[ NORTH_EAST ] && m_node[ NORTH_EAST ]->IsOnDisplacement() ) ||
+		( m_node[ SOUTH_EAST ] && m_node[ SOUTH_EAST ]->IsOnDisplacement() ) ||
+		( m_node[ SOUTH_WEST ] && m_node[ SOUTH_WEST ]->IsOnDisplacement() );
+
+	if ( !isOnDisplacement && !IsFlat() )
+		return false;
+
+	bool areaIsOnDisplacement = ( area->m_node[ NORTH_WEST ] && area->m_node[ NORTH_WEST ]->IsOnDisplacement() ) ||
+		( area->m_node[ NORTH_EAST ] && area->m_node[ NORTH_EAST ]->IsOnDisplacement() ) ||
+		( area->m_node[ SOUTH_EAST ] && area->m_node[ SOUTH_EAST ]->IsOnDisplacement() ) ||
+		( area->m_node[ SOUTH_WEST ] && area->m_node[ SOUTH_WEST ]->IsOnDisplacement() );
+
+	if ( !areaIsOnDisplacement && !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
+	float tolerance = nav_coplanar_slope_limit.GetFloat();
+	if ( ( m_node[ NORTH_WEST ] && m_node[ NORTH_WEST ]->IsOnDisplacement() ) ||
+		( m_node[ NORTH_EAST ] && m_node[ NORTH_EAST ]->IsOnDisplacement() ) ||
+		( m_node[ SOUTH_EAST ] && m_node[ SOUTH_EAST ]->IsOnDisplacement() ) ||
+		( m_node[ SOUTH_WEST ] && m_node[ SOUTH_WEST ]->IsOnDisplacement() ) )
+	{
+		tolerance = nav_coplanar_slope_limit_displacement.GetFloat();
+	}
+
+	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( float x, float y ) const RESTRICT
+{
+	// guard against division by zero due to degenerate areas
+#ifdef _X360 
+	// do the compare-against-zero on the integer unit to avoid a fcmp
+	// IEEE754 float positive zero is simply 0x00. There is also a 
+	// floating-point negative zero (-0.0f == 0x80000000), but given 
+	// how m_inv is computed earlier, that's not a possible value for
+	// it here, so we don't have to check for that.
+	//
+	// oddly, the compiler isn't smart enough to do this on its own
+	if ( *reinterpret_cast<const unsigned *>(&m_invDxCorners) == 0 ||
+		 *reinterpret_cast<const unsigned *>(&m_invDyCorners) == 0 )
+		return m_neZ;
+#else
+	if (m_invDxCorners == 0.0f || m_invDyCorners == 0.0f)
+		return m_neZ;
+#endif
+
+	float u = (x - m_nwCorner.x) * m_invDxCorners;
+	float v = (y - m_nwCorner.y) * m_invDyCorners;
+
+	// clamp Z values to (x,y) volume
+	
+	u = fsel( u, u, 0 );			// u >= 0 ? u : 0
+	u = fsel( u - 1.0f, 1.0f, u );	// u >= 1 ? 1 : u
+
+	v = fsel( v, v, 0 );			// v >= 0 ? v : 0
+	v = fsel( v - 1.0f, 1.0f, v );	// v >= 1 ? 1 : v
+
+	float northZ = m_nwCorner.z + u * (m_neZ - m_nwCorner.z);
+	float southZ = m_swZ + u * (m_seCorner.z - m_swZ);
+
+	return northZ + v * (southZ - northZ);
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return closest point to 'pos' on 'area'.
+ * Returned point is in 'close'.
+ */
+void CNavArea::GetClosestPointOnArea( const Vector * RESTRICT pPos, Vector *close ) const RESTRICT 
+{
+	float x, y, z;
+
+	// Using fsel rather than compares, as much faster on 360 [7/28/2008 tom]
+	x = fsel( pPos->x - m_nwCorner.x, pPos->x, m_nwCorner.x );
+	x = fsel( x - m_seCorner.x, m_seCorner.x, x );
+
+	y = fsel( pPos->y - m_nwCorner.y, pPos->y, m_nwCorner.y );
+	y = fsel( y - m_seCorner.y, m_seCorner.y, y );
+
+	z = GetZ( x, y );
+
+	close->Init( x, y, z );
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return shortest distance squared between point and this area
+ */
+float CNavArea::GetDistanceSquaredToPoint( const Vector &pos ) const
+{
+	if (pos.x < m_nwCorner.x)
+	{
+		if (pos.y < m_nwCorner.y)
+		{
+			// position is north-west of area
+			return (m_nwCorner - pos).LengthSqr();
+		}
+		else if (pos.y > m_seCorner.y)
+		{
+			// position is south-west of area
+			Vector d;
+			d.x = m_nwCorner.x - pos.x;
+			d.y = m_seCorner.y - pos.y;
+			d.z = m_swZ - pos.z;
+			return d.LengthSqr();
+		}
+		else
+		{
+			// position is west of area
+			float d = m_nwCorner.x - pos.x;
+			return d * d;
+		}
+	}
+	else if (pos.x > m_seCorner.x)
+	{
+		if (pos.y < m_nwCorner.y)
+		{
+			// position is north-east of area
+			Vector d;
+			d.x = m_seCorner.x - pos.x;
+			d.y = m_nwCorner.y - pos.y;
+			d.z = m_neZ - pos.z;
+			return d.LengthSqr();
+		}
+		else if (pos.y > m_seCorner.y)
+		{
+			// position is south-east of area
+			return (m_seCorner - pos).LengthSqr();
+		}
+		else
+		{
+			// position is east of area
+			float d = pos.x - m_seCorner.x;
+			return d * d;
+		}
+	}
+	else if (pos.y < m_nwCorner.y)
+	{
+		// position is north of area
+		float d = m_nwCorner.y - pos.y;
+		return d * d;
+	}
+	else if (pos.y > m_seCorner.y)
+	{
+		// position is south of area
+		float d = pos.y - m_seCorner.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_VEC( m_connect[ dir ], it )
+	{
+		if (i == which)
+			return m_connect[ dir ][ it ].area;
+
+		++i;
+	}
+
+	return NULL;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+// Build a vector of all adjacent areas
+void CNavArea::CollectAdjacentAreas( CUtlVector< CNavArea * > *adjVector ) const
+{
+	for( int d=0; d<NUM_DIRECTIONS; ++d )
+	{
+		for( int i=0; i<m_connect[d].Count(); ++i )
+		{
+			adjVector->AddToTail( m_connect[d].Element(i).area );
+		}
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Compute "portal" between two 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_nwCorner.y;
+		}
+		else
+		{
+			center->y = m_seCorner.y;
+		}
+
+		float left = MAX( m_nwCorner.x, to->m_nwCorner.x );
+		float right = MIN( m_seCorner.x, to->m_seCorner.x );
+
+		// clamp to our extent in case areas are disjoint
+		if ( left < m_nwCorner.x )
+		{
+			left = m_nwCorner.x;
+		}
+		else if ( left > m_seCorner.x )
+		{
+			left = m_seCorner.x;
+		}
+
+		if ( right < m_nwCorner.x )
+		{
+			right = m_nwCorner.x;
+		}
+		else if ( right > m_seCorner.x )
+		{
+			right = m_seCorner.x;
+		}
+
+		center->x = ( left + right )/2.0f;
+		*halfWidth = ( right - left )/2.0f;
+	}
+	else	// EAST or WEST
+	{
+		if ( dir == WEST )
+		{
+			center->x = m_nwCorner.x;
+		}
+		else
+		{
+			center->x = m_seCorner.x;
+		}
+
+		float top = MAX( m_nwCorner.y, to->m_nwCorner.y );
+		float bottom = MIN( m_seCorner.y, to->m_seCorner.y );
+
+		// clamp to our extent in case areas are disjoint
+		if ( top < m_nwCorner.y )
+		{
+			top = m_nwCorner.y;
+		}
+		else if ( top > m_seCorner.y )
+		{
+			top = m_seCorner.y;
+		}
+
+		if ( bottom < m_nwCorner.y )
+		{
+			bottom = m_nwCorner.y;
+		}
+		else if ( bottom > m_seCorner.y )
+		{
+			bottom = m_seCorner.y;
+		}
+
+		center->y = (top + bottom)/2.0f;
+		*halfWidth = (bottom - top)/2.0f;
+	}
+
+	center->z = GetZ( center->x, center->y );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+// compute largest portal to adjacent area, returning direction
+NavDirType CNavArea::ComputeLargestPortal( const CNavArea *to, Vector *center, float *halfWidth ) const
+{
+	NavDirType bestDir = NUM_DIRECTIONS;
+	Vector bestCenter( vec3_origin );
+	float bestHalfWidth = 0.0f;
+
+	Vector centerDir = to->GetCenter() - GetCenter();
+
+	for ( int i=0; i<NUM_DIRECTIONS; ++i )
+	{
+		NavDirType testDir = (NavDirType)i;
+		Vector testCenter;
+		float testHalfWidth;
+
+		// Make sure we're not picking the opposite direction
+		switch ( testDir )
+		{
+		case NORTH:	// -y
+			if ( centerDir.y >= 0.0f )
+				continue;
+			break;
+		case SOUTH:	// +y
+			if ( centerDir.y <= 0.0f )
+				continue;
+			break;
+		case WEST:	// -x
+			if ( centerDir.x >= 0.0f )
+				continue;
+			break;
+		case EAST:	// +x
+			if ( centerDir.x <= 0.0f )
+				continue;
+			break;
+		}
+
+		ComputePortal( to, testDir, &testCenter, &testHalfWidth );
+		if ( testHalfWidth > bestHalfWidth )
+		{
+			bestDir = testDir;
+			bestCenter = testCenter;
+			bestHalfWidth = testHalfWidth;
+		}
+	}
+
+	*center = bestCenter;
+	*halfWidth = bestHalfWidth;
+	return bestDir;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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 = 0.0f; //GenerationStepSize/2.0f;  // causes trouble with very small/narrow nav areas
+	const float margin = GenerationStepSize;
+
+	if ( dir == NORTH || dir == SOUTH )
+	{
+		if ( dir == NORTH )
+		{
+			closePos->y = m_nwCorner.y;
+		}
+		else
+		{
+			closePos->y = m_seCorner.y;
+		}
+
+		float left = MAX( m_nwCorner.x, to->m_nwCorner.x );
+		float right = MIN( m_seCorner.x, to->m_seCorner.x );
+
+		// clamp to our extent in case areas are disjoint
+		// no good - need to push into to area for margins
+		/*
+		if (left < m_nwCorner.x)
+			left = m_nwCorner.x;
+		else if (left > m_seCorner.x)
+			left = m_seCorner.x;
+
+		if (right < m_nwCorner.x)
+			right = m_nwCorner.x;
+		else if (right > m_seCorner.x)
+			right = m_seCorner.x;
+			*/
+
+		// keep margin if against edge
+		/// @todo Need better check whether edge is outer edge or not - partial overlap is missed
+		float leftMargin = ( to->IsEdge( WEST ) ) ? ( left + margin ) : left;
+		float rightMargin = ( to->IsEdge( EAST ) ) ? ( right - margin ) : right;
+		
+		// if area is narrow, margins may have crossed
+		if ( leftMargin > rightMargin )
+		{
+			// use midline
+			float mid = ( left + right )/2.0f;
+			leftMargin = mid;
+			rightMargin = mid;
+		}
+
+		// 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_nwCorner.x;
+		}
+		else
+		{
+			closePos->x = m_seCorner.x;
+		}
+
+		float top = MAX( m_nwCorner.y, to->m_nwCorner.y );
+		float bottom = MIN( m_seCorner.y, to->m_seCorner.y );
+
+		// clamp to our extent in case areas are disjoint
+		// no good - need to push into to area for margins
+		/*
+		if (top < m_nwCorner.y)
+			top = m_nwCorner.y;
+		else if (top > m_seCorner.y)
+			top = m_seCorner.y;
+
+		if (bottom < m_nwCorner.y)
+			bottom = m_nwCorner.y;
+		else if (bottom > m_seCorner.y)
+			bottom = m_seCorner.y;
+		*/
+		
+		// keep margin if against edge
+		float topMargin = ( to->IsEdge( NORTH ) ) ? ( top + margin ) : top;
+		float bottomMargin = ( to->IsEdge( SOUTH ) ) ? ( bottom - margin ) : bottom;
+
+		// if area is narrow, margins may have crossed
+		if ( topMargin > bottomMargin )
+		{
+			// use midline
+			float mid = ( top + bottom )/2.0f;
+			topMargin = mid;
+			bottomMargin = mid;
+		}
+
+		// 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;
+		}
+	}
+
+	closePos->z = GetZ( closePos->x, closePos->y );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return true if the given area and 'other' share a colinear edge (ie: no drop-down or step/jump/climb)
+ */
+bool CNavArea::IsContiguous( const CNavArea *other ) const
+{
+	VPROF_BUDGET( "CNavArea::IsContiguous", "NextBot" );
+
+	// find which side it is connected on
+	int dir;
+	for( dir=0; dir<NUM_DIRECTIONS; ++dir )
+	{
+		if ( IsConnected( other, (NavDirType)dir ) )
+			break;
+	}
+
+	if ( dir == NUM_DIRECTIONS )
+		return false;
+
+	Vector myEdge;
+	float halfWidth;
+	ComputePortal( other, (NavDirType)dir, &myEdge, &halfWidth );
+
+	Vector otherEdge;
+	other->ComputePortal( this, OppositeDirection( (NavDirType)dir ), &otherEdge, &halfWidth );
+
+	// must use stepheight because rough terrain can have gaps/cracks between adjacent nav areas
+	return ( myEdge - otherEdge ).IsLengthLessThan( StepHeight );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return height change between edges of adjacent nav areas (not actual underlying ground)
+ */
+float CNavArea::ComputeAdjacentConnectionHeightChange( const CNavArea *destinationArea ) const
+{
+	VPROF_BUDGET( "CNavArea::ComputeAdjacentConnectionHeightChange", "NextBot" );
+
+	// find which side it is connected on
+	int dir;
+	for( dir=0; dir<NUM_DIRECTIONS; ++dir )
+	{
+		if ( IsConnected( destinationArea, (NavDirType)dir ) )
+			break;
+	}
+
+	if ( dir == NUM_DIRECTIONS )
+		return FLT_MAX;
+
+	Vector myEdge;
+	float halfWidth;
+	ComputePortal( destinationArea, (NavDirType)dir, &myEdge, &halfWidth );
+
+	Vector otherEdge;
+	destinationArea->ComputePortal( this, OppositeDirection( (NavDirType)dir ), &otherEdge, &halfWidth );
+
+	return otherEdge.z - myEdge.z;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return true if there are no bi-directional links on the given side
+ */
+bool CNavArea::IsEdge( NavDirType dir ) const
+{
+	FOR_EACH_VEC( 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_nwCorner.x && point->x <= m_seCorner.x)
+	{
+		if (point->y < m_nwCorner.y)
+			return NORTH;
+		else if (point->y > m_seCorner.y)
+			return SOUTH;
+	}
+	else if (point->y >= m_nwCorner.y && point->y <= m_seCorner.y)
+	{
+		if (point->x < m_nwCorner.x)
+			return WEST;
+		else if (point->x > m_seCorner.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;
+
+	const float DebugDuration = NDEBUG_PERSIST_TILL_NEXT_SERVER;
+
+	if ( TheNavMesh->IsEditMode( CNavMesh::PLACE_PAINTING ) )
+	{
+		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
+		{
+			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, DebugDuration );
+	}
+
+	Vector nw, ne, sw, se;
+
+	nw = m_nwCorner;
+	se = m_seCorner;
+	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 ( nav_show_light_intensity.GetBool() )
+	{
+		for ( int i=0; i<NUM_CORNERS; ++i )
+		{
+			Vector pos = GetCorner( (NavCornerType)i );
+			Vector end = pos;
+			float lightIntensity = GetLightIntensity(pos);
+			end.z += HumanHeight*lightIntensity;
+			lightIntensity *= 255; // for color
+			NDebugOverlay::Line( end, pos, lightIntensity, lightIntensity, MAX( 192, lightIntensity ), true, DebugDuration );
+		}
+	}
+
+	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, DebugDuration );
+			NDebugOverlay::Triangle( se+offset, nw+offset, sw+offset, bgcolor[0], bgcolor[1], bgcolor[2], bgcolor[3], true, DebugDuration );
+		}
+	}
+
+	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->IsEditMode( CNavMesh::NORMAL ) )
+	{
+		NavCornerType bestCorner = GetCornerUnderCursor();
+
+		Vector p[NUM_CORNERS];
+		if ( 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 );
+	}
+
+	if (GetAttributes() & NAV_MESH_STAIRS)
+	{
+		if ( useAttributeColors )
+			color = NavAttributeStairColor;
+
+		float northZ = ( GetCorner( NORTH_WEST ).z + GetCorner( NORTH_EAST ).z ) / 2.0f;
+		float southZ = ( GetCorner( SOUTH_WEST ).z + GetCorner( SOUTH_EAST ).z ) / 2.0f;
+		float westZ = ( GetCorner( NORTH_WEST ).z + GetCorner( SOUTH_WEST ).z ) / 2.0f;
+		float eastZ = ( GetCorner( NORTH_EAST ).z + GetCorner( SOUTH_EAST ).z ) / 2.0f;
+
+		float deltaEastWest = abs( westZ - eastZ );
+		float deltaNorthSouth = abs( northZ - southZ );
+
+		float stepSize = StepHeight / 2.0f;
+		float t;
+
+		if ( deltaEastWest > deltaNorthSouth )
+		{
+			float inc = stepSize / GetSizeX();
+
+			for( t = 0.0f; t <= 1.0f; t += inc )
+			{
+				float x = m_nwCorner.x + t * GetSizeX();
+				
+				NavDrawLine( Vector( x, m_nwCorner.y, GetZ( x, m_nwCorner.y ) ), 
+							 Vector( x, m_seCorner.y, GetZ( x, m_seCorner.y ) ),
+							 color );
+			}
+		}
+		else
+		{
+			float inc = stepSize / GetSizeY();
+
+			for( t = 0.0f; t <= 1.0f; t += inc )
+			{
+				float y = m_nwCorner.y + t * GetSizeY();
+
+				NavDrawLine( Vector( m_nwCorner.x, y, GetZ( m_nwCorner.x, y ) ),
+							 Vector( m_seCorner.x, y, GetZ( m_seCorner.x, y ) ),
+							 color );
+			}
+		}
+	}
+
+	// Stop is represented by an octagon
+	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 );
+	}
+
+	if ( IsBlocked( TEAM_ANY ) || HasAvoidanceObstacle() || IsDamaging() )
+	{
+		NavEditColor color = (IsBlocked( TEAM_ANY ) && ( m_attributeFlags & NAV_MESH_NAV_BLOCKER ) ) ? NavBlockedByFuncNavBlockerColor : NavBlockedByDoorColor;
+		const float blockedInset = 4.0f;
+		nw.x += blockedInset;
+		nw.y += blockedInset;
+		ne.x -= blockedInset;
+		ne.y += blockedInset;
+		sw.x += blockedInset;
+		sw.y -= blockedInset;
+		se.x -= blockedInset;
+		se.y -= blockedInset;
+		NavDrawLine( nw, ne, color );
+		NavDrawLine( ne, se, color );
+		NavDrawLine( se, sw, color );
+		NavDrawLine( sw, nw, color );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Draw area as a filled rect of the given color
+ */
+void CNavArea::DrawFilled( int r, int g, int b, int a, float deltaT, bool noDepthTest, float margin ) const
+{
+	Vector nw = GetCorner( NORTH_WEST ) + Vector( margin, margin, 0.0f );
+	Vector ne = GetCorner( NORTH_EAST ) + Vector( -margin, margin, 0.0f );
+	Vector sw = GetCorner( SOUTH_WEST ) + Vector( margin, -margin, 0.0f );
+	Vector se = GetCorner( SOUTH_EAST ) + Vector( -margin, -margin, 0.0f );
+
+	if ( a == 0 )
+	{
+		NDebugOverlay::Line( nw, ne, r, g, b, true, deltaT );
+		NDebugOverlay::Line( nw, sw, r, g, b, true, deltaT );
+		NDebugOverlay::Line( sw, se, r, g, b, true, deltaT );
+		NDebugOverlay::Line( se, ne, r, g, b, true, deltaT );
+	}
+	else
+	{
+		NDebugOverlay::Triangle( nw, se, ne, r, g, b, a, noDepthTest, deltaT );
+		NDebugOverlay::Triangle( se, nw, sw, r, g, b, a, noDepthTest, deltaT );
+	}
+
+	// backside
+// 	NDebugOverlay::Triangle( nw, ne, se, r, g, b, a, noDepthTest, deltaT );
+// 	NDebugOverlay::Triangle( se, sw, nw, r, g, b, a, noDepthTest, deltaT );
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+void CNavArea::DrawSelectedSet( const Vector &shift ) const
+{
+	const float deltaT = NDEBUG_PERSIST_TILL_NEXT_SERVER;
+	int r = s_selectedSetColor.r();
+	int g = s_selectedSetColor.g();
+	int b = s_selectedSetColor.b();
+	int a = s_selectedSetColor.a();
+
+	Vector nw = GetCorner( NORTH_WEST ) + shift;
+	Vector ne = GetCorner( NORTH_EAST ) + shift;
+	Vector sw = GetCorner( SOUTH_WEST ) + shift;
+	Vector se = GetCorner( SOUTH_EAST ) + shift;
+
+	NDebugOverlay::Triangle( nw, se, ne, r, g, b, a, true, deltaT );
+	NDebugOverlay::Triangle( se, nw, sw, r, g, b, a, true, deltaT );
+
+	r = s_selectedSetBorderColor.r();
+	g = s_selectedSetBorderColor.g();
+	b = s_selectedSetBorderColor.b();
+	NDebugOverlay::Line( nw, ne, r, g, b, true, deltaT );
+	NDebugOverlay::Line( nw, sw, r, g, b, true, deltaT );
+	NDebugOverlay::Line( sw, se, r, g, b, true, deltaT );
+	NDebugOverlay::Line( se, ne, r, g, b, true, deltaT );
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+void CNavArea::DrawDragSelectionSet( Color &dragSelectionSetColor ) const
+{
+	const float deltaT = NDEBUG_PERSIST_TILL_NEXT_SERVER;
+	int r = dragSelectionSetColor.r();
+	int g = dragSelectionSetColor.g();
+	int b = dragSelectionSetColor.b();
+	int a = dragSelectionSetColor.a();
+
+	Vector nw = GetCorner( NORTH_WEST );
+	Vector ne = GetCorner( NORTH_EAST );
+	Vector sw = GetCorner( SOUTH_WEST );
+	Vector se = GetCorner( SOUTH_EAST );
+
+	NDebugOverlay::Triangle( nw, se, ne, r, g, b, a, true, deltaT );
+	NDebugOverlay::Triangle( se, nw, sw, r, g, b, a, true, deltaT );
+
+	r = s_dragSelectionSetBorderColor.r();
+	g = s_dragSelectionSetBorderColor.g();
+	b = s_dragSelectionSetBorderColor.b();
+	NDebugOverlay::Line( nw, ne, r, g, b, true, deltaT );
+	NDebugOverlay::Line( nw, sw, r, g, b, true, deltaT );
+	NDebugOverlay::Line( sw, se, r, g, b, true, deltaT );
+	NDebugOverlay::Line( se, ne, r, g, b, true, deltaT );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Draw navigation areas and edit them
+ */
+void CNavArea::DrawHidingSpots( void ) const
+{
+	const HidingSpotVector *hidingSpots = GetHidingSpots();
+
+	FOR_EACH_VEC( (*hidingSpots), it )
+	{
+		const HidingSpot *spot = (*hidingSpots)[ 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->IsEditMode( CNavMesh::PLACE_PAINTING ))
+	{
+		Draw();
+	}
+	else
+	{
+		Draw();
+		DrawHidingSpots();
+	}
+
+	// draw connected ladders
+	{
+		FOR_EACH_VEC( 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_VEC( 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->IsEditMode( CNavMesh::PLACE_PAINTING ) )
+			{
+				adj->DrawHidingSpots();
+
+				Vector from, to;
+				Vector hookPos;
+				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;
+				}
+
+				from.z = GetZ( from );
+				to.z = adj->GetZ( to );
+
+				Vector drawTo;
+				adj->GetClosestPointOnArea( to, &drawTo );
+
+				if ( nav_show_contiguous.GetBool() )
+				{
+					if ( IsContiguous( adj ) )
+						NavDrawLine( from, drawTo, NavConnectedContiguous );
+					else
+						NavDrawLine( from, drawTo, NavConnectedNonContiguous );
+				}
+				else
+				{
+					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 )
+{
+	Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == NULL );
+
+	if ( IsOpen() )
+	{
+		// already on list
+		return;
+	}
+
+	// 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;
+		m_openListTail = 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 ( 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;
+
+		m_openListTail = this;
+	}
+
+	Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == NULL );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Add to tail of the open list
+ */
+void CNavArea::AddToOpenListTail( void )
+{
+	Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == NULL );
+
+	if ( IsOpen() )
+	{
+		// already on list
+		return;
+	}
+
+	// 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;
+		m_openListTail = this;
+		this->m_prevOpen = NULL;
+		this->m_nextOpen = NULL;
+
+		Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == NULL );
+		return;
+	}
+
+	// append to end of list
+	m_openListTail->m_nextOpen = this;
+
+	this->m_prevOpen = m_openListTail;
+	this->m_nextOpen = NULL;
+
+	m_openListTail = this;
+
+	Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == 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;
+		}
+		else
+		{
+			m_openListTail = this;
+		}
+	}
+}
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavArea::RemoveFromOpenList( void )
+{
+	if ( m_openMarker == 0 )
+	{
+		// not on the list
+		return;
+	}
+
+	if ( m_prevOpen )
+	{
+		m_prevOpen->m_nextOpen = m_nextOpen;
+	}
+	else
+	{
+		m_openList = m_nextOpen;
+	}
+	
+	if ( m_nextOpen )
+	{
+		m_nextOpen->m_prevOpen = m_prevOpen;
+	}
+	else
+	{
+		m_openListTail = 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;
+	m_openListTail = NULL;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavArea::SetCorner( NavCornerType corner, const Vector& newPosition )
+{
+	switch( corner )
+	{
+		case NORTH_WEST:
+			m_nwCorner = newPosition;
+			break;
+
+		case NORTH_EAST:
+			m_seCorner.x = newPosition.x;
+			m_nwCorner.y = newPosition.y;
+			m_neZ = newPosition.z;
+			break;
+
+		case SOUTH_WEST:
+			m_nwCorner.x = newPosition.x;
+			m_seCorner.y = newPosition.y;
+			m_swZ = newPosition.z;
+			break;
+
+		case SOUTH_EAST:
+			m_seCorner = newPosition;
+			break;
+
+		default:
+		{
+			Vector oldPosition = GetCenter();
+			Vector delta = newPosition - oldPosition;
+			m_nwCorner += delta;
+			m_seCorner += delta;
+			m_neZ += delta.z;
+			m_swZ += delta.z;
+		}
+	}
+
+	m_center.x = (m_nwCorner.x + m_seCorner.x)/2.0f;
+	m_center.y = (m_nwCorner.y + m_seCorner.y)/2.0f;
+	m_center.z = (m_nwCorner.z + m_seCorner.z)/2.0f;
+
+	if ( ( m_seCorner.x - m_nwCorner.x ) > 0.0f && ( m_seCorner.y - m_nwCorner.y ) > 0.0f )
+	{
+		m_invDxCorners = 1.0f / ( m_seCorner.x - m_nwCorner.x );
+		m_invDyCorners = 1.0f / ( m_seCorner.y - m_nwCorner.y );
+	}
+	else
+	{
+		m_invDxCorners = m_invDyCorners = 0;
+	}
+
+	CalcDebugID();
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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_VEC( m_hidingSpots, it )
+	{
+		const HidingSpot *spot = m_hidingSpots[ 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_NPCSOLID_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_NPCSOLID_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;
+	}
+
+	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, "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_hidingSpots.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_VEC( 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_nwCorner.x < extent.lo)
+					extent.lo = connect.area->m_nwCorner.x;
+
+				if (connect.area->m_seCorner.x > extent.hi)
+					extent.hi = connect.area->m_seCorner.x;			
+			}
+			else
+			{
+				if (connect.area->m_nwCorner.y < extent.lo)
+					extent.lo = connect.area->m_nwCorner.y;
+
+				if (connect.area->m_seCorner.y > extent.hi)
+					extent.hi = connect.area->m_seCorner.y;
+			}
+		}
+
+		switch( d )
+		{
+			case NORTH:
+				if (extent.lo - m_nwCorner.x >= cornerSize)
+					++cornerCount[ NORTH_WEST ];
+
+				if (m_seCorner.x - extent.hi >= cornerSize)
+					++cornerCount[ NORTH_EAST ];
+				break;
+
+			case SOUTH:
+				if (extent.lo - m_nwCorner.x >= cornerSize)
+					++cornerCount[ SOUTH_WEST ];
+
+				if (m_seCorner.x - extent.hi >= cornerSize)
+					++cornerCount[ SOUTH_EAST ];
+				break;
+
+			case EAST:
+				if (extent.lo - m_nwCorner.y >= cornerSize)
+					++cornerCount[ NORTH_EAST ];
+
+				if (m_seCorner.y - extent.hi >= cornerSize)
+					++cornerCount[ SOUTH_EAST ];
+				break;
+
+			case WEST:
+				if (extent.lo - m_nwCorner.y >= cornerSize)
+					++cornerCount[ NORTH_WEST ];
+
+				if (m_seCorner.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_hidingSpots.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.z += HumanEyeHeight;
+	}
+	else
+	{
+		// we are crouching when at this hiding spot
+		eye.z += HumanCrouchEyeHeight;
+	}
+
+	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 );
+
+	Extent areaExtent;
+	FOR_EACH_VEC( TheNavAreas, it )
+	{
+		CNavArea *area = TheNavAreas[ it ];
+
+		area->GetExtent( &areaExtent );
+
+		// scan this area
+		for( walkable.y = areaExtent.lo.y + GenerationStepSize/2.0f; walkable.y < areaExtent.hi.y; walkable.y += GenerationStepSize )
+		{
+			for( walkable.x = areaExtent.lo.x + GenerationStepSize/2.0f; walkable.x < areaExtent.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_VEC( m_hidingSpots, it )
+	{
+		HidingSpot *spot = m_hidingSpots[ 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_VEC( m_spotEncounters, it )
+		{
+			e = m_spotEncounters[ 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 = HumanEyeHeight;
+	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_VEC( TheHidingSpots, it )
+		{
+			spot = TheHidingSpots[ 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_NPCSOLID_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->spots.AddToTail( spotOrder );
+				}
+			}
+
+			// mark spot as encountered
+			spot->Mark();
+		}
+	}
+
+	// add encounter to list
+	m_spotEncounters.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_spotEncounters.RemoveAll();
+
+	if (nav_quicksave.GetBool())
+		return;
+
+	// for each adjacent area
+	for( int fromDir=0; fromDir<NUM_DIRECTIONS; ++fromDir )
+	{
+		FOR_EACH_VEC( 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_VEC( 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 )
+{
+	for( int i=0; i<MAX_NAV_TEAMS; ++i )
+	{
+		float deltaT = gpGlobals->curtime - m_dangerTimestamp[i];
+		float decayAmount = GetDangerDecayRate() * 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 ];
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Returns a 0..1 light intensity for the given point
+ */
+float CNavArea::GetLightIntensity( const Vector &pos ) const
+{
+	Vector testPos;
+	testPos.x = clamp( pos.x, m_nwCorner.x, m_seCorner.x );
+	testPos.y = clamp( pos.y, m_nwCorner.y, m_seCorner.y );
+	testPos.z = pos.z;
+
+	float dX = (testPos.x - m_nwCorner.x) / (m_seCorner.x - m_nwCorner.x);
+	float dY = (testPos.y - m_nwCorner.y) / (m_seCorner.y - m_nwCorner.y);
+
+	float northLight = m_lightIntensity[ NORTH_WEST ] * ( 1 - dX ) + m_lightIntensity[ NORTH_EAST ] * dX;
+	float southLight = m_lightIntensity[ SOUTH_WEST ] * ( 1 - dX ) + m_lightIntensity[ SOUTH_EAST ] * dX;
+	float light = northLight * ( 1 - dY ) + southLight * dY;
+
+	return light;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Returns a 0..1 light intensity for the given point
+ */
+float CNavArea::GetLightIntensity( float x, float y ) const
+{
+	return GetLightIntensity( Vector( x, y, 0 ) );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Returns a 0..1 light intensity averaged over the whole area
+ */
+float CNavArea::GetLightIntensity( void ) const
+{
+	float light = m_lightIntensity[ NORTH_WEST ];
+	light += m_lightIntensity[ NORTH_EAST ];
+	light += m_lightIntensity[ SOUTH_WEST];
+	light += m_lightIntensity[ SOUTH_EAST ];
+	return light / 4.0f;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Compute light intensity at corners and center (requires client via listenserver)
+ */
+bool CNavArea::ComputeLighting( void )
+{
+	if ( engine->IsDedicatedServer() )
+	{
+		for ( int i=0; i<NUM_CORNERS; ++i )
+		{
+			m_lightIntensity[i] = 1.0f;
+		}
+
+		return true;
+	}
+
+	// Calculate light at the corners
+	for ( int i=0; i<NUM_CORNERS; ++i )
+	{
+		Vector pos = FindPositionInArea( this, (NavCornerType)i );
+		pos.z = GetZ( pos ) + HalfHumanHeight - StepHeight;	// players light from their centers, and we light from slightly below that, to allow for low ceilings
+		float height;
+		if ( TheNavMesh->GetGroundHeight( pos, &height ) )
+		{
+			pos.z = height + HalfHumanHeight - StepHeight;	// players light from their centers, and we light from slightly below that, to allow for low ceilings
+		}
+
+		Vector light( 0, 0, 0 );
+		// FIXMEL4DTOMAINMERGE
+		//if ( !engine->GetLightForPointListenServerOnly( pos, false, &light ) )
+		//{
+			//NDebugOverlay::Line( pos, pos + Vector( 0, 0, -100 ), 255, 0, 0, false, 100.0f );
+		//	return false;
+		//}
+
+		Vector ambientColor;
+		// FIXMEL4DTOMAINMERGE
+		//if ( !GetTerrainAmbientLightAtPoint( pos, &ambientColor ) )
+		{
+			//NDebugOverlay::Line( pos, pos + Vector( 0, 0, -100 ), 255, 127, 0, false, 100.0f );
+			return false;
+		}
+
+		//NDebugOverlay::Line( pos, pos + Vector( 0, 0, -100 ), 0, 255, 127, false, 100.0f );
+
+		float ambientIntensity = ambientColor.x + ambientColor.y + ambientColor.z;
+		float lightIntensity = light.x + light.y + light.z;
+		lightIntensity = clamp( lightIntensity, 0.f, 1.f );	// sum can go well over 1.0, but it's the lower region we care about.  if it's bright, we don't need to know *how* bright.
+
+		lightIntensity = MAX( lightIntensity, ambientIntensity );
+
+		m_lightIntensity[i] = lightIntensity;
+	}
+
+	return true;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+CON_COMMAND_F( nav_update_lighting, "Recomputes lighting values", FCVAR_CHEAT )
+{
+	if ( !UTIL_IsCommandIssuedByServerAdmin() )
+		return;
+
+	int numComputed = 0;
+	if ( args.ArgC() == 2 )
+	{
+		int areaID = atoi( args[1] );
+		CNavArea *area = TheNavMesh->GetNavAreaByID( areaID );
+		if ( area )
+		{
+			if ( area->ComputeLighting() )
+			{
+				++numComputed;
+			}
+		}
+	}
+	else
+	{
+		FOR_EACH_VEC( TheNavAreas, index )
+		{
+			CNavArea *area = TheNavAreas[ index ];
+			if ( area->ComputeLighting() )
+			{
+				++numComputed;
+			}
+		}
+	}
+	DevMsg( "Computed lighting for %d/%d areas\n", numComputed, TheNavAreas.Count() );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * 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_nwCorner.z += amount;
+		break;
+	case NORTH_EAST:
+		m_neZ += amount;
+		break;
+	case SOUTH_WEST:
+		m_swZ += amount;
+		break;
+	case SOUTH_EAST:
+		m_seCorner.z += amount;
+		break;
+	}
+
+	// Recompute the center
+	m_center.x = (m_nwCorner.x + m_seCorner.x)/2.0f;
+	m_center.y = (m_nwCorner.y + m_seCorner.y)/2.0f;
+	m_center.z = (m_nwCorner.z + m_seCorner.z)/2.0f;
+
+	if ( ( m_seCorner.x - m_nwCorner.x ) > 0.0f && ( m_seCorner.y - m_nwCorner.y ) > 0.0f )
+	{
+		m_invDxCorners = 1.0f / ( m_seCorner.x - m_nwCorner.x );
+		m_invDyCorners = 1.0f / ( m_seCorner.y - m_nwCorner.y );
+	}
+	else
+	{
+		m_invDxCorners = m_invDyCorners = 0;
+	}
+
+	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;
+
+			NavAreaVector *areas = &TheNavMesh->m_grid[ x + y*TheNavMesh->m_gridSizeX ];
+
+			// find closest area in this cell
+			FOR_EACH_VEC( (*areas), it )
+			{
+				CNavArea *area = (*areas)[ 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), 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_nwCorner + Vector ( inset, inset, 0 );
+	Vector se = m_seCorner + 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, newZ - nw.z );
+	}
+
+	if ( corner == NORTH_EAST || corner == NUM_CORNERS )
+	{
+		float newZ = FindGroundZ( ne, nw, se );
+		RaiseCorner( NORTH_EAST, newZ - ne.z );
+	}
+
+	if ( corner == SOUTH_WEST || corner == NUM_CORNERS )
+	{
+		float newZ = FindGroundZ( sw, nw, se );
+		RaiseCorner( SOUTH_WEST, newZ - sw.z );
+	}
+
+	if ( corner == SOUTH_EAST || corner == NUM_CORNERS )
+	{
+		float newZ = FindGroundZ( se, ne, sw );
+		RaiseCorner( SOUTH_EAST, newZ - se.z );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Shift the nav area
+ */
+void CNavArea::Shift( const Vector &shift )
+{
+	m_nwCorner += shift;
+	m_seCorner += shift;
+	
+	m_center += shift;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+static void CommandNavUpdateBlocked( void )
+{
+	if ( !UTIL_IsCommandIssuedByServerAdmin() )
+		return;
+
+	if ( TheNavMesh->GetMarkedArea() )
+	{
+		CNavArea *area = TheNavMesh->GetMarkedArea();
+		area->UpdateBlocked( true );
+		if ( area->IsBlocked( TEAM_ANY ) )
+		{
+			DevMsg( "Area #%d %s is blocked\n", area->GetID(), VecToString( area->GetCenter() + Vector( 0, 0, HalfHumanHeight ) ) );
+		}
+	}
+	else
+	{
+		float start = Plat_FloatTime();
+		CNavArea *blockedArea = NULL;
+		FOR_EACH_VEC( TheNavAreas, nit )
+		{
+			CNavArea *area = TheNavAreas[ nit ];
+			area->UpdateBlocked( true );
+			if ( area->IsBlocked( TEAM_ANY ) )
+			{
+				DevMsg( "Area #%d %s is blocked\n", area->GetID(), VecToString( area->GetCenter() + Vector( 0, 0, HalfHumanHeight ) ) );
+				if ( !blockedArea )
+				{
+					blockedArea = area;
+				}
+			}
+		}
+
+		float end = Plat_FloatTime();
+		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 );
+
+
+//--------------------------------------------------------------------------------------------------------
+bool CNavArea::IsBlocked( int teamID, bool ignoreNavBlockers ) const
+{
+	if ( ignoreNavBlockers && ( m_attributeFlags & NAV_MESH_NAV_BLOCKER ) )
+	{
+		return false;
+	}
+
+#ifdef TERROR
+	if ( ( teamID == TEAM_SURVIVOR ) && ( m_attributeFlags & CNavArea::NAV_PLAYERCLIP ) )
+		return true;
+#endif
+
+	if ( teamID == TEAM_ANY )
+	{
+		bool isBlocked = false;
+		for ( int i=0; i<MAX_NAV_TEAMS; ++i )
+		{
+			isBlocked |= m_isBlocked[ i ];
+		}
+
+		return isBlocked;
+	}
+
+	int teamIdx = teamID % MAX_NAV_TEAMS;
+	return m_isBlocked[ teamIdx ];
+}
+
+//--------------------------------------------------------------------------------------------------------
+void CNavArea::MarkAsBlocked( int teamID, CBaseEntity *blocker, bool bGenerateEvent )
+{
+	if ( blocker && blocker->ClassMatches( "func_nav_blocker" ) )
+	{
+		m_attributeFlags |= NAV_MESH_NAV_BLOCKER;
+	}
+
+	bool wasBlocked = false;
+	if ( teamID == TEAM_ANY )
+	{
+		for ( int i=0; i<MAX_NAV_TEAMS; ++i )
+		{
+			wasBlocked |= m_isBlocked[ i ];
+			m_isBlocked[ i ] = true;
+		}
+	}
+	else
+	{
+		int teamIdx = teamID % MAX_NAV_TEAMS;
+		wasBlocked |= m_isBlocked[ teamIdx ];
+		m_isBlocked[ teamIdx ] = true;
+	}
+
+	if ( !wasBlocked )
+	{
+		if ( bGenerateEvent )
+		{
+			IGameEvent * event = gameeventmanager->CreateEvent( "nav_blocked" );
+			if ( event )
+			{
+				event->SetInt( "area", m_id );
+				event->SetInt( "blocked", 1 );
+				gameeventmanager->FireEvent( event );
+			}
+		}
+
+		if ( nav_debug_blocked.GetBool() )
+		{
+			if ( blocker )
+			{
+				ConColorMsg( Color( 0, 255, 128, 255 ), "%s %d blocked area %d\n", blocker->GetDebugName(), blocker->entindex(), GetID() );
+			}
+			else
+			{
+				ConColorMsg( Color( 0, 255, 128, 255 ), "non-entity blocked area %d\n", GetID() );
+			}
+		}
+		TheNavMesh->OnAreaBlocked( this );
+	}
+	else
+	{
+		if ( nav_debug_blocked.GetBool() )
+		{
+			if ( blocker )
+			{
+				ConColorMsg( Color( 0, 255, 128, 255 ), "DUPE: %s %d blocked area %d\n", blocker->GetDebugName(), blocker->entindex(), GetID() );
+			}
+			else
+			{
+				ConColorMsg( Color( 0, 255, 128, 255 ), "DUPE: non-entity blocked area %d\n", GetID() );
+			}
+		}
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+// checks if any func_nav_blockers are still blocking the area
+void CNavArea::UpdateBlockedFromNavBlockers( void )
+{
+	VPROF( "CNavArea::UpdateBlockedFromNavBlockers" );
+	Extent bounds;
+	GetExtent( &bounds );
+
+	// Save off old values, reset to not blocked state
+	m_attributeFlags &= ~NAV_MESH_NAV_BLOCKER;
+	bool oldBlocked[MAX_NAV_TEAMS];
+	bool wasBlocked = false;
+	for ( int i=0; i<MAX_NAV_TEAMS; ++i )
+	{
+		oldBlocked[i] = m_isBlocked[i];
+		wasBlocked = wasBlocked || m_isBlocked[i];
+		m_isBlocked[i] = false;
+	}
+
+	bool isBlocked = CFuncNavBlocker::CalculateBlocked( m_isBlocked, bounds.lo, bounds.hi );
+
+	if ( isBlocked )
+	{
+		m_attributeFlags |= NAV_MESH_NAV_BLOCKER;
+	}
+
+	// If we're unblocked, fire a nav_blocked event.
+	if ( wasBlocked != isBlocked )
+	{
+		IGameEvent * event = gameeventmanager->CreateEvent( "nav_blocked" );
+		if ( event )
+		{
+			event->SetInt( "area", m_id );
+			event->SetInt( "blocked", isBlocked );
+			gameeventmanager->FireEvent( event );
+		}
+
+		if ( isBlocked )
+		{
+			if ( nav_debug_blocked.GetBool() )
+			{
+				ConColorMsg( Color( 0, 255, 128, 255 ), "area %d is blocked by a nav blocker\n", GetID() );
+			}
+			TheNavMesh->OnAreaBlocked( this );
+		}
+		else
+		{
+			if ( nav_debug_blocked.GetBool() )
+			{
+				ConColorMsg( Color( 0, 128, 255, 255 ), "area %d is unblocked by a nav blocker\n", GetID() );
+			}
+			TheNavMesh->OnAreaUnblocked( this );
+		}
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavArea::UnblockArea( int teamID )
+{
+	bool wasBlocked = IsBlocked( teamID );
+
+	if ( teamID == TEAM_ANY )
+	{
+		for ( int i=0; i<MAX_NAV_TEAMS; ++i )
+		{
+			m_isBlocked[ i ] = false;
+		}
+	}
+	else
+	{
+		int teamIdx = teamID % MAX_NAV_TEAMS;
+		m_isBlocked[ teamIdx ] = false;
+	}
+
+	if ( wasBlocked )
+	{
+		IGameEvent * event = gameeventmanager->CreateEvent( "nav_blocked" );
+		if ( event )
+		{
+			event->SetInt( "area", m_id );
+			event->SetInt( "blocked", false );
+			gameeventmanager->FireEvent( event );
+		}
+
+		if ( nav_debug_blocked.GetBool() )
+		{
+			ConColorMsg( Color( 255, 0, 128, 255 ), "area %d is unblocked by UnblockArea\n", GetID() );
+		}
+		TheNavMesh->OnAreaUnblocked( this );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Updates the (un)blocked status of the nav area
+ * The semantics of this method have gotten very muddled - needs refactoring (MSB 5/7/09)
+ */
+void CNavArea::UpdateBlocked( bool force, int teamID )
+{
+	VPROF( "CNavArea::UpdateBlocked" );
+	if ( !force && !m_blockedTimer.IsElapsed() )
+	{
+		return;
+	}
+
+	const float MaxBlockedCheckInterval = 5;
+	float interval = m_blockedTimer.GetCountdownDuration() + 1;
+	if ( interval > MaxBlockedCheckInterval )
+	{
+		interval = MaxBlockedCheckInterval;
+	}
+	m_blockedTimer.Start( interval );
+
+	if ( ( m_attributeFlags & NAV_MESH_NAV_BLOCKER ) )
+	{
+		if ( force )
+		{
+			UpdateBlockedFromNavBlockers();
+		}
+		return;
+	}
+
+	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 ) );
+	Extent bounds;
+	bounds.lo.Init( -sizeX, -sizeY, 0 );
+	bounds.hi.Init( sizeX, sizeY, VEC_DUCK_HULL_MAX.z - HalfHumanHeight );
+
+	bool wasBlocked = IsBlocked( TEAM_ANY );
+
+	// See if spot is valid
+#ifdef TERROR
+	// don't unblock func_doors
+	CTraceFilterWalkableEntities filter( NULL, COLLISION_GROUP_PLAYER_MOVEMENT, WALK_THRU_PROP_DOORS | WALK_THRU_BREAKABLES );
+#else
+	CTraceFilterWalkableEntities filter( NULL, COLLISION_GROUP_PLAYER_MOVEMENT, WALK_THRU_DOORS | WALK_THRU_BREAKABLES );
+#endif
+	trace_t tr;
+	{
+	VPROF( "CNavArea::UpdateBlocked-Trace" );
+	UTIL_TraceHull(
+		origin,
+		origin,
+		bounds.lo,
+		bounds.hi,
+		MASK_NPCSOLID_BRUSHONLY,
+		&filter,
+		&tr );
+
+	}
+
+	if ( !tr.startsolid )
+	{
+		// unblock ourself
+#ifdef TERROR
+		extern ConVar DebugZombieBreakables;
+		if ( DebugZombieBreakables.GetBool() )
+#else
+		if ( false )
+#endif
+
+		{
+			NDebugOverlay::Box( origin, bounds.lo, bounds.hi, 0, 255, 0, 10, 5.0f );
+		}
+		else
+		{
+			for ( int i=0; i<MAX_NAV_TEAMS; ++i )
+			{
+				m_isBlocked[ i ] = false;
+			}
+		}
+	}
+	else if ( force )
+	{
+		if ( teamID == TEAM_ANY )
+		{
+			for ( int i=0; i<MAX_NAV_TEAMS; ++i )
+			{
+				m_isBlocked[ i ] = true;
+			}
+		}
+		else
+		{
+			int teamIdx = teamID % MAX_NAV_TEAMS;
+			m_isBlocked[ teamIdx ] = true;
+		}
+	}
+
+	bool isBlocked = IsBlocked( TEAM_ANY );
+
+	if ( wasBlocked != isBlocked )
+	{
+		VPROF( "CNavArea::UpdateBlocked-Event" );
+		IGameEvent * event = gameeventmanager->CreateEvent( "nav_blocked" );
+		if ( event )
+		{
+			event->SetInt( "area", m_id );
+			event->SetInt( "blocked", isBlocked );
+			gameeventmanager->FireEvent( event );
+		}
+
+		if ( isBlocked )
+		{
+			TheNavMesh->OnAreaBlocked( this );
+		}
+		else
+		{
+			TheNavMesh->OnAreaUnblocked( this );
+		}
+	}
+
+	if ( TheNavMesh->GetMarkedArea() == this )
+	{
+		if ( IsBlocked( teamID ) )
+		{
+			NDebugOverlay::Box( origin, bounds.lo, bounds.hi, 255, 0, 0, 64, 3.0f );
+		}
+		else
+		{
+			NDebugOverlay::Box( origin, bounds.lo, bounds.hi, 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 ( IsBlocked( TEAM_ANY ) )
+		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 );
+
+	// See if spot is valid
+	trace_t tr;
+	UTIL_TraceHull(
+		origin,
+		origin,
+		mins,
+		maxs,
+		MASK_NPCSOLID_BRUSHONLY,
+		ignore,
+		COLLISION_GROUP_PLAYER_MOVEMENT,
+		&tr );
+
+	// If the center is open space, we're effectively blocked
+	if ( !tr.startsolid )
+	{
+		MarkAsBlocked( TEAM_ANY, NULL );
+	}
+
+	/*
+	if ( IsBlocked( TEAM_ANY ) )
+	{
+		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::MarkObstacleToAvoid( float obstructionHeight )
+{
+	if ( m_avoidanceObstacleHeight < obstructionHeight )
+	{
+		if ( m_avoidanceObstacleHeight == 0 )
+		{
+			TheNavMesh->OnAvoidanceObstacleEnteredArea( this );
+		}
+
+		m_avoidanceObstacleHeight = obstructionHeight;
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Updates the (un)obstructed status of the nav area
+ */
+void CNavArea::UpdateAvoidanceObstacles( void )
+{
+	if ( !m_avoidanceObstacleTimer.IsElapsed() )
+	{
+		return;
+	}
+
+	const float MaxBlockedCheckInterval = 5;
+	float interval = m_blockedTimer.GetCountdownDuration() + 1;
+	if ( interval > MaxBlockedCheckInterval )
+	{
+		interval = MaxBlockedCheckInterval;
+	}
+	m_avoidanceObstacleTimer.Start( interval );
+
+	Vector mins = m_nwCorner;
+	Vector maxs = m_seCorner;
+
+	mins.z = MIN( m_nwCorner.z, m_seCorner.z );
+	maxs.z = MAX( m_nwCorner.z, m_seCorner.z ) + HumanCrouchHeight;
+
+	float obstructionHeight = 0.0f;
+	for ( int i=0; i<TheNavMesh->GetObstructions().Count(); ++i )
+	{
+		INavAvoidanceObstacle *obstruction = TheNavMesh->GetObstructions()[i];
+		CBaseEntity *obstructingEntity = obstruction->GetObstructingEntity();
+		if ( !obstructingEntity )
+			continue;
+
+		// check if the aabb intersects the search aabb.
+		Vector vecSurroundMins, vecSurroundMaxs;
+		obstructingEntity->CollisionProp()->WorldSpaceSurroundingBounds( &vecSurroundMins, &vecSurroundMaxs );
+		if ( !IsBoxIntersectingBox( mins, maxs, vecSurroundMins, vecSurroundMaxs ) )
+			continue;
+
+		if ( !obstruction->CanObstructNavAreas() )
+			continue;
+
+		float propHeight = obstruction->GetNavObstructionHeight();
+
+		obstructionHeight = MAX( obstructionHeight, propHeight );
+	}
+
+	m_avoidanceObstacleHeight = obstructionHeight;
+
+	if ( m_avoidanceObstacleHeight == 0.0f )
+	{
+		TheNavMesh->OnAvoidanceObstacleLeftArea( this );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+// Clear set of func_nav_cost entities that affect this area
+void CNavArea::ClearAllNavCostEntities( void )
+{
+	RemoveAttributes( NAV_MESH_FUNC_COST );
+	m_funcNavCostVector.RemoveAll();
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+// Add the given func_nav_cost entity to the cost of this area
+void CNavArea::AddFuncNavCostEntity( CFuncNavCost *cost )
+{
+	SetAttributes( NAV_MESH_FUNC_COST );
+	m_funcNavCostVector.AddToTail( cost );
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+// Return the cost multiplier of this area's func_nav_cost entities for the given actor
+float CNavArea::ComputeFuncNavCost( CBaseCombatCharacter *who ) const
+{
+	float funcCost = 1.0f;
+
+	for( int i=0; i<m_funcNavCostVector.Count(); ++i )
+	{
+		if ( m_funcNavCostVector[i] != NULL )
+		{
+			funcCost *= m_funcNavCostVector[i]->GetCostMultiplier( who );
+		}
+	}
+
+	return funcCost;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+bool CNavArea::HasFuncNavAvoid( void ) const
+{
+	for( int i=0; i<m_funcNavCostVector.Count(); ++i )
+	{
+		CFuncNavAvoid *avoid = dynamic_cast< CFuncNavAvoid * >( m_funcNavCostVector[i].Get() );
+		if ( avoid )
+		{
+			return true;
+		}
+	}
+
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+bool CNavArea::HasFuncNavPrefer( void ) const
+{
+	for( int i=0; i<m_funcNavCostVector.Count(); ++i )
+	{
+		CFuncNavPrefer *prefer = dynamic_cast< CFuncNavPrefer * >( m_funcNavCostVector[i].Get() );
+		if ( prefer )
+		{
+			return true;
+		}
+	}
+
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+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( TEAM_ANY ) )
+		{
+			DevMsg( "Area #%d %s is blocked\n", area->GetID(), VecToString( area->GetCenter() + Vector( 0, 0, HalfHumanHeight ) ) );
+		}
+	}
+	else
+	{
+		float start = Plat_FloatTime();
+		FOR_EACH_VEC( TheNavAreas, nit )
+		{
+			CNavArea *area = TheNavAreas[ nit ];
+			area->CheckFloor( NULL );
+			if ( area->IsBlocked( TEAM_ANY ) )
+			{
+				DevMsg( "Area #%d %s is blocked\n", area->GetID(), VecToString( area->GetCenter() + Vector( 0, 0, HalfHumanHeight ) ) );
+			}
+		}
+
+		float end = Plat_FloatTime();
+		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 );
+
+
+//--------------------------------------------------------------------------------------------------------------
+bool SelectOverlappingAreas::operator()( CNavArea *area )
+{
+	CNavArea *overlappingArea = NULL;
+	CNavLadder *overlappingLadder = NULL;
+
+	Vector nw = area->GetCorner( NORTH_WEST );
+	Vector se = area->GetCorner( SOUTH_EAST );
+	Vector start = nw;
+	start.x += GenerationStepSize/2;
+	start.y += GenerationStepSize/2;
+
+	while ( start.x < se.x )
+	{
+		start.y = nw.y + GenerationStepSize/2;
+		while ( start.y < se.y )
+		{
+			start.z = area->GetZ( start.x, start.y );
+			Vector end = start;
+			start.z -= StepHeight;
+			end.z += HalfHumanHeight;
+
+			if ( TheNavMesh->FindNavAreaOrLadderAlongRay( start, end, &overlappingArea, &overlappingLadder, area ) )
+			{
+				if ( overlappingArea )
+				{
+					TheNavMesh->AddToSelectedSet( overlappingArea );
+					TheNavMesh->AddToSelectedSet( area );
+				}
+			}
+
+			start.y += GenerationStepSize;
+		}
+		start.x += GenerationStepSize;
+	}
+	return true;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+static void CommandNavSelectOverlapping( void )
+{
+	if ( !UTIL_IsCommandIssuedByServerAdmin() )
+		return;
+
+	TheNavMesh->ClearSelectedSet();
+
+	SelectOverlappingAreas overlapCheck;
+	TheNavMesh->ForAllAreas( overlapCheck );
+
+	Msg( "%d overlapping areas selected\n", TheNavMesh->GetSelecteSetSize() );
+}
+static ConCommand nav_select_overlapping( "nav_select_overlapping", CommandNavSelectOverlapping, "Selects nav areas that are overlapping others.", FCVAR_GAMEDLL );
+
+
+//--------------------------------------------------------------------------------------------------------
+static byte m_PVS[PAD_NUMBER( MAX_MAP_CLUSTERS,8 ) / 8];
+static int m_nPVSSize;		// PVS size in bytes
+
+CUtlHash< NavVisPair_t, CVisPairHashFuncs, CVisPairHashFuncs > *g_pNavVisPairHash;
+
+#define MASK_NAV_VISION				(MASK_BLOCKLOS_AND_NPCS|CONTENTS_IGNORE_NODRAW_OPAQUE)
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Set PVS to only include the Potentially Visible Set as seen from anywhere
+ * within this nav area
+ */
+void CNavArea::SetupPVS( void ) const
+{
+	m_nPVSSize = sizeof( m_PVS );
+	engine->ResetPVS( m_PVS, m_nPVSSize );
+
+	const float margin = GenerationStepSize/2.0f;
+	Vector eye( 0, 0, 0.75f * HumanHeight );
+
+	// step across area checking visibility to given area
+	Vector shift( eye );
+	for( shift.y = margin; shift.y <= GetSizeY() - margin; shift.y += GenerationStepSize )
+	{
+		for( shift.x = margin; shift.x <= GetSizeX() - margin; shift.x += GenerationStepSize )
+		{
+			// Optimization:
+			// If we are already POTENTIALLY_VISIBLE, and no longer COMPLETELY_VISIBLE, there's
+			// no way for vis to change again.
+			Vector testPos( GetCorner( NORTH_WEST ) + shift );
+			testPos.z = GetZ( testPos ) + eye.z;
+
+			engine->AddOriginToPVS( testPos );
+		}
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Return true if this area is within the current PVS
+ */
+bool CNavArea::IsInPVS( void ) const
+{
+	Vector eye( 0, 0, 0.75f * HumanHeight );
+
+	Extent areaExtent;
+	
+	areaExtent.lo = GetCenter() + eye;
+	areaExtent.hi = areaExtent.lo;
+
+	areaExtent.Encompass( GetCorner( NORTH_WEST ) + eye );
+	areaExtent.Encompass( GetCorner( NORTH_EAST ) + eye );
+	areaExtent.Encompass( GetCorner( SOUTH_WEST ) + eye );
+	areaExtent.Encompass( GetCorner( SOUTH_EAST ) + eye );
+
+	return engine->CheckBoxInPVS( areaExtent.lo, areaExtent.hi, m_PVS, m_nPVSSize );
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Do actual line-of-sight traces to determine if any part of given area is visible from this area
+ */
+CNavArea::VisibilityType CNavArea::ComputeVisibility( const CNavArea *area, bool isPVSValid, bool bCheckPVS, bool *pOutsidePVS ) const
+{
+	float distanceSq = area->GetCenter().DistToSqr( GetCenter() );
+
+	if ( nav_max_view_distance.GetFloat() > 0.00001f )
+	{
+		// limit range of visibility check
+		if ( distanceSq > Sqr( nav_max_view_distance.GetFloat() ) )
+		{
+			// too far to be visible
+			return NOT_VISIBLE;
+		}
+	}
+
+	if ( !isPVSValid )
+	{
+		SetupPVS();
+	}
+
+	Vector eye( 0, 0, 0.75f * HumanHeight );
+
+	if ( bCheckPVS )
+	{
+		Extent areaExtent;
+		areaExtent.lo = areaExtent.hi = area->GetCenter() + eye;
+		areaExtent.Encompass( area->GetCorner( NORTH_WEST ) + eye );
+		areaExtent.Encompass( area->GetCorner( NORTH_EAST ) + eye );
+		areaExtent.Encompass( area->GetCorner( SOUTH_WEST ) + eye );
+		areaExtent.Encompass( area->GetCorner( SOUTH_EAST ) + eye );
+		if ( !engine->CheckBoxInPVS( areaExtent.lo, areaExtent.hi, m_PVS, m_nPVSSize ) )
+		{
+			if ( pOutsidePVS )
+				*pOutsidePVS = true;
+			return NOT_VISIBLE;
+		}
+
+		if ( pOutsidePVS )
+			*pOutsidePVS = false;
+	}
+
+	//------------------------------------
+	Vector vThisNW = GetCorner( NORTH_WEST ) + eye;
+	Vector vThisNE = GetCorner( NORTH_EAST ) + eye;
+	Vector vThisSW = GetCorner( SOUTH_WEST ) + eye;
+	Vector vThisSE = GetCorner( SOUTH_EAST ) + eye;
+	Vector vThisCenter = GetCenter() + eye;
+
+	Vector vTraceMins( vThisNW );
+	Vector vTraceMaxs( vThisSE );
+
+	vTraceMins.z = MIN( MIN( MIN( vThisNW.z, vThisNE.z ), vThisSE.z ), vThisSW.z );
+	vTraceMaxs.z = MAX( MAX( MAX( vThisNW.z, vThisNE.z ), vThisSE.z ), vThisSW.z ) + 0.1;
+
+	vTraceMins -= vThisCenter;
+	vTraceMaxs -= vThisCenter;
+
+	Vector vOtherMins( area->GetCorner( NORTH_WEST) );
+	Vector vOtherMaxs( area->GetCorner( SOUTH_EAST) );
+
+	Vector vTarget;
+	CalcClosestPointOnAABB( vOtherMins, vOtherMaxs, vThisCenter, vTarget );
+	vTarget.z = area->GetZ( vTarget ) + eye.z;
+
+	trace_t tr;
+	CTraceFilterNoNPCsOrPlayer traceFilter( NULL, COLLISION_GROUP_NONE );
+
+	UTIL_TraceHull( vThisCenter, vTarget, vTraceMins, vTraceMaxs, MASK_NAV_VISION, &traceFilter, &tr );
+
+	if ( tr.fraction == 1.0 ||  ( tr.endpos.x > vOtherMins.x && tr.endpos.x < vOtherMaxs.x && tr.endpos.y > vOtherMins.y && tr.endpos.y < vOtherMaxs.y ) )
+	{
+		return COMPLETELY_VISIBLE; // Counter-intuitive: the way this function was written, "COMPLETELY_VISIBLE" actually means "I am completely visible to the other"
+	}
+
+	//------------------------------------
+	// check line of sight between areas
+	unsigned char vis = COMPLETELY_VISIBLE;
+
+	const float margin = GenerationStepSize/2.0f;
+
+	Vector shift( 0, 0, 0.75f * HumanHeight );
+
+	// always check center to catch very small areas
+	if ( area->IsPartiallyVisible( GetCenter() + eye ) )
+	{
+		vis |= POTENTIALLY_VISIBLE;
+	}
+	else
+	{
+		vis &= ~COMPLETELY_VISIBLE;
+	}
+
+	Vector eyeToCenter( GetCenter() - area->GetCenter() );
+	eyeToCenter.NormalizeInPlace();
+	float angleTolerance = nav_potentially_visible_dot_tolerance.GetFloat();	// if corner-to-eye angles are this close to center-to-eye angles, assume the same result and skip the trace
+
+	// step across area checking visibility to given area
+	for( shift.y = margin; shift.y <= GetSizeY() - margin; shift.y += GenerationStepSize )
+	{
+		for( shift.x = margin; shift.x <= GetSizeX() - margin; shift.x += GenerationStepSize )
+		{
+			// Optimization:
+			// If we are already POTENTIALLY_VISIBLE, and no longer COMPLETELY_VISIBLE, there's
+			// no way for vis to change again.
+			if ( vis == POTENTIALLY_VISIBLE )
+				return POTENTIALLY_VISIBLE;
+
+			Vector testPos( GetCorner( NORTH_WEST ) + shift );
+			testPos.z = GetZ( testPos ) + eye.z;
+
+			// Optimization - treat long-distance traces that are effectively collinear as the same
+			if ( distanceSq > Sqr( 1000 ) )
+			{
+				Vector eyeToCorner( testPos - (GetCenter() + eye) );
+				eyeToCorner.NormalizeInPlace();
+				if ( eyeToCorner.Dot( eyeToCenter ) >= angleTolerance )
+				{
+					continue;
+				}
+			}
+
+			if ( area->IsPartiallyVisible( testPos ) )
+			{
+				vis |= POTENTIALLY_VISIBLE;
+			}
+			else
+			{
+				vis &= ~COMPLETELY_VISIBLE;
+			}
+		}
+	}
+
+	return (VisibilityType)vis;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Return a list of the delta between our visibility list and the given adjacent area
+ */
+const CNavArea::CAreaBindInfoArray &CNavArea::ComputeVisibilityDelta( const CNavArea *other ) const
+{
+	static CAreaBindInfoArray delta;
+
+	delta.RemoveAll();
+	
+	// do not delta from a delta - if 'other' is already inheriting, use its inherited source directly
+	if ( other->m_inheritVisibilityFrom.area != NULL )
+	{
+		Assert( false && "Visibility inheriting from inherited area" );
+
+		delta = m_potentiallyVisibleAreas;
+		return delta;
+	}
+
+	// add any visible areas in my list that are not in 'others' list into the delta
+	int i, j;
+	for( i=0; i<m_potentiallyVisibleAreas.Count(); ++i )
+	{
+		if ( m_potentiallyVisibleAreas[i].area )
+		{
+			// is my visible area also in adjacent area's vis list
+			for( j=0; j<other->m_potentiallyVisibleAreas.Count(); ++j )
+			{
+				if ( m_potentiallyVisibleAreas[i].area == other->m_potentiallyVisibleAreas[j].area &&
+					 m_potentiallyVisibleAreas[i].attributes == other->m_potentiallyVisibleAreas[j].attributes )
+				{
+					// mutually identically visible
+					break;
+				}
+			}
+
+			if ( j == other->m_potentiallyVisibleAreas.Count() )
+			{
+				// my vis area not in adjacent area's vis list or has different visibility attributes - add to delta
+				delta.AddToTail( m_potentiallyVisibleAreas[i] );
+			}
+		}
+	}
+
+	// add explicit NOT_VISIBLE references to areas in 'others' list that are NOT in mine
+	for( j=0; j<other->m_potentiallyVisibleAreas.Count(); ++j )
+	{
+		if ( other->m_potentiallyVisibleAreas[j].area )
+		{
+			for( i=0; i<m_potentiallyVisibleAreas.Count(); ++i )
+			{
+				if ( m_potentiallyVisibleAreas[i].area == other->m_potentiallyVisibleAreas[j].area )
+				{
+					// area in both lists - already handled in delta above
+					break;
+				}
+			}
+
+			if ( i == m_potentiallyVisibleAreas.Count() )
+			{
+				// 'other' has area in their list that we don't - mark it explicitly NOT_VISIBLE
+				AreaBindInfo info;
+				info.area = other->m_potentiallyVisibleAreas[j].area;
+				info.attributes = NOT_VISIBLE;
+
+				delta.AddToTail( info );
+			}
+		}
+	}
+
+	return delta;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+void CNavArea::ResetPotentiallyVisibleAreas()
+{
+	m_potentiallyVisibleAreas.RemoveAll();
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Determine visibility between areas.
+ * Compute full list of all areas visible for each area.  This list will be compressed into deltas
+ * in the PostCustomAnalysis() step.
+ */
+
+CNavArea *g_pCurVisArea;
+CTSListWithFreeList< CNavArea::AreaBindInfo > g_ComputedVis;
+
+void CNavArea::ComputeVisToArea( CNavArea *&pOtherArea )
+{
+	CNavArea *area = assert_cast< CNavArea * >( pOtherArea );
+	VisibilityType visThisToOther = ( area == g_pCurVisArea ) ? COMPLETELY_VISIBLE : NOT_VISIBLE;
+	VisibilityType visOtherToThis = NOT_VISIBLE;
+
+	if ( area != g_pCurVisArea )
+	{
+		bool bOutsidePVS;
+
+		visOtherToThis = g_pCurVisArea->ComputeVisibility( area, true, true, &bOutsidePVS ); // TODO: Hacky right now. Compute visibility for the "complete" case actually returns how completely visible the area is to the other. Should fix it to be more clear [1/30/2009 tom]
+
+		if ( !bOutsidePVS && ( visOtherToThis || ( g_pCurVisArea->GetCenter() - area->GetCenter() ).LengthSqr() < Sqr( nav_max_view_distance.GetFloat() ) ) )
+		{
+			visThisToOther = area->ComputeVisibility( g_pCurVisArea, true, false );
+		}
+
+		if ( !visOtherToThis && visThisToOther )
+		{
+			visOtherToThis = POTENTIALLY_VISIBLE;
+		}
+
+		if ( !visThisToOther && visOtherToThis )
+		{
+			visThisToOther = POTENTIALLY_VISIBLE;
+		}
+	}
+
+	CNavArea::AreaBindInfo info;
+	if ( visThisToOther != NOT_VISIBLE )
+	{
+		info.area = area;
+		info.attributes = visThisToOther;
+		g_ComputedVis.PushItem( info );
+	}
+
+	if ( visOtherToThis != NOT_VISIBLE )
+	{
+		info.area = g_pCurVisArea;
+		info.attributes = visOtherToThis;
+		area->m_potentiallyVisibleAreas.AddToTail( info );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Determine visibility from this area to all potentially/completely visible areas in the mesh
+ */
+void CNavArea::ComputeVisibilityToMesh( void )
+{
+	m_inheritVisibilityFrom.area = NULL;
+	m_isInheritedFrom = false;
+
+	// collect all possible nav areas that could be visible from this area
+	NavAreaCollector collector;
+	float radius = nav_max_view_distance.GetFloat();
+	if ( radius == 0.0f )
+	{
+		radius = DEF_NAV_VIEW_DISTANCE;
+	}
+	collector.m_area.EnsureCapacity( 1000 );
+	TheNavMesh->ForAllAreasInRadius( collector, GetCenter(), radius );
+
+	NavVisPair_t visPair;
+	UtlHashHandle_t hHash;
+
+	// First eliminate the ones already calculated
+	for ( int i = collector.m_area.Count() - 1; i >= 0; --i )
+	{
+		visPair.SetPair( this, collector.m_area[i] );
+
+		hHash = g_pNavVisPairHash->Find( visPair );
+		if ( hHash != g_pNavVisPairHash->InvalidHandle() )
+		{
+			collector.m_area.FastRemove( i );
+		}
+	}
+
+	SetupPVS();
+
+	g_pCurVisArea = this;
+	ParallelProcess( "CNavArea::ComputeVisibilityToMesh", collector.m_area.Base(), collector.m_area.Count(), &ComputeVisToArea );
+
+	m_potentiallyVisibleAreas.EnsureCapacity( g_ComputedVis.Count() );
+	while ( g_ComputedVis.Count() )
+	{
+		g_ComputedVis.PopItem( &m_potentiallyVisibleAreas[ m_potentiallyVisibleAreas.AddToTail() ] );
+	}
+
+	FOR_EACH_VEC( collector.m_area, it )
+	{
+		visPair.SetPair( this, (CNavArea *)collector.m_area[it] );
+		Assert( g_pNavVisPairHash->Find( visPair ) == g_pNavVisPairHash->InvalidHandle() );
+		g_pNavVisPairHash->Insert( visPair );
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * The center and all four corners must ALL be visible
+ */
+bool CNavArea::IsEntirelyVisible( const Vector &eye, const CBaseEntity *ignore ) const
+{
+	Vector corner;
+	trace_t result;
+	CTraceFilterNoNPCsOrPlayer traceFilter( ignore, COLLISION_GROUP_NONE );
+	const float offset = 0.75f * HumanHeight;
+
+	// check center
+	UTIL_TraceLine( eye, GetCenter() + Vector( 0, 0, offset ), MASK_NAV_VISION, &traceFilter, &result );
+	if (result.fraction < 1.0f)
+	{
+		return false;
+	}
+
+	for( int c=0; c<NUM_CORNERS; ++c )
+	{
+		corner = GetCorner( (NavCornerType)c );
+		UTIL_TraceLine( eye, corner + Vector( 0, 0, offset ), MASK_NAV_VISION, &traceFilter, &result );
+		if (result.fraction < 1.0f)
+		{
+			return false;
+		}
+	}
+
+	// all points are visible
+	return true;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * The center or any of the four corners may be visible
+ */
+bool CNavArea::IsPartiallyVisible( const Vector &eye, const CBaseEntity *ignore ) const
+{
+	Vector corner;
+	trace_t result;
+	CTraceFilterNoNPCsOrPlayer traceFilter( ignore, COLLISION_GROUP_NONE );
+	const float offset = 0.75f * HumanHeight;
+
+	// check center
+	UTIL_TraceLine( eye, GetCenter() + Vector( 0, 0, offset ), MASK_NAV_VISION, &traceFilter, &result );
+	if (result.fraction >= 1.0f)
+	{
+		return true;
+	}
+
+	Vector eyeToCenter( GetCenter() + Vector( 0, 0, offset ) - eye );
+	eyeToCenter.NormalizeInPlace();
+	float angleTolerance = nav_potentially_visible_dot_tolerance.GetFloat();	// if corner-to-eye angles are this close to center-to-eye angles, assume the same result and skip the trace
+
+	for( int c=0; c<NUM_CORNERS; ++c )
+	{
+		corner = GetCorner( (NavCornerType)c ) + Vector( 0, 0, offset );
+
+		// Optimization - treat traces that are effectively collinear as the same
+		Vector eyeToCorner( corner - eye );
+		eyeToCorner.NormalizeInPlace();
+		if ( eyeToCorner.Dot( eyeToCenter ) >= angleTolerance )
+		{
+			continue;
+		}
+
+		UTIL_TraceLine( eye, corner + Vector( 0, 0, offset ), MASK_NAV_VISION, &traceFilter, &result );
+		if (result.fraction >= 1.0f)
+		{
+			return true;
+		}
+	}
+
+	// nothing is visible
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+bool CNavArea::IsPotentiallyVisible( const CNavArea *viewedArea ) const
+{
+	VPROF_BUDGET( "CNavArea::IsPotentiallyVisible", "NextBot" );
+
+	if ( viewedArea == NULL )
+	{
+		return false;
+	}
+
+	// can always see ourselves
+	if ( viewedArea == this )
+	{
+		return true;
+	}
+
+	// normal visibility check
+	for ( int i=0; i<m_potentiallyVisibleAreas.Count(); ++i )
+	{
+		if ( m_potentiallyVisibleAreas[i].area == viewedArea )
+		{
+			// Found area in our list. We might be a delta from another list, 
+			// and NOT_VISIBLE overrides that list.
+			return ( m_potentiallyVisibleAreas[i].attributes != NOT_VISIBLE );
+		}
+	}
+
+	// viewedArea is not in our visibility list, check inherited set
+	if ( m_inheritVisibilityFrom.area )
+	{
+		CAreaBindInfoArray &inherited = m_inheritVisibilityFrom.area->m_potentiallyVisibleAreas;
+
+		for ( int i=0; i<inherited.Count(); ++i )
+		{
+			if ( inherited[i].area == viewedArea )
+			{
+				return ( inherited[i].attributes != NOT_VISIBLE );
+			}
+		}
+	}
+	
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+bool CNavArea::IsCompletelyVisible( const CNavArea *viewedArea ) const
+{
+	VPROF_BUDGET( "CNavArea::IsCompletelyVisible", "NextBot" );
+
+	if ( viewedArea == NULL )
+	{
+		return false;
+	}
+
+	// can always see ourselves
+	if ( viewedArea == this )
+	{
+		return true;
+	}
+
+	// normal visibility check
+	for ( int i=0; i<m_potentiallyVisibleAreas.Count(); ++i )
+	{
+		if ( m_potentiallyVisibleAreas[i].area == viewedArea )
+		{
+			// our list is definitive - viewedArea is in our list, but is not completely visible
+			return ( m_potentiallyVisibleAreas[i].attributes & COMPLETELY_VISIBLE ) ? true : false;
+		}
+	}
+
+	// viewedArea is not in our visibility list, check inherited set
+	if ( m_inheritVisibilityFrom.area )
+	{
+		CAreaBindInfoArray &inherited = m_inheritVisibilityFrom.area->m_potentiallyVisibleAreas;
+
+		for ( int i=0; i<inherited.Count(); ++i )
+		{
+			if ( inherited[i].area == viewedArea )
+			{
+				return ( inherited[i].attributes & COMPLETELY_VISIBLE ) ? true : false;
+			}
+		}
+	}
+
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Return true if any portion of this area is visible to anyone on the given team
+ */
+bool CNavArea::IsPotentiallyVisibleToTeam( int teamIndex ) const
+{
+	VPROF_BUDGET( "CNavArea::IsPotentiallyVisibleToTeam", "NextBot" );
+
+	CTeam *team = GetGlobalTeam( teamIndex );
+
+	for( int i = 0; i < team->GetNumPlayers(); ++i )
+	{
+		if ( team->GetPlayer(i)->IsAlive() )
+		{
+			CNavArea *from = (CNavArea *)team->GetPlayer(i)->GetLastKnownArea();
+			
+			if ( from && from->IsPotentiallyVisible( this ) )
+			{
+				return true;
+			}
+		}
+	}
+	
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+/**
+ * Return true if given area is completely visible from somewhere in this area by someone on the team (very fast)
+ */
+bool CNavArea::IsCompletelyVisibleToTeam( int teamIndex ) const
+{
+	VPROF_BUDGET( "CNavArea::IsCompletelyVisibleToTeam", "NextBot" );
+
+	CTeam *team = GetGlobalTeam( teamIndex );
+
+	for( int i = 0; i < team->GetNumPlayers(); ++i )
+	{
+		if ( team->GetPlayer(i)->IsAlive() )
+		{
+			CNavArea *from = (CNavArea *)team->GetPlayer(i)->GetLastKnownArea();
+
+			if ( from && from->IsCompletelyVisible( this ) )
+			{
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+Vector CNavArea::GetRandomPoint( void ) const
+{
+	Extent extent;
+	GetExtent( &extent );
+
+	Vector spot;
+	spot.x = RandomFloat( extent.lo.x, extent.hi.x ); 
+	spot.y = RandomFloat( extent.lo.y, extent.hi.y );
+	spot.z = GetZ( spot.x, spot.y );
+
+	return spot;
+}
+
+
+
+
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+