source-engine/game/server/nav_area.h

//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: 
//
// $NoKeywords: $
//
//=============================================================================//
// nav_area.h
// Navigation areas
// Author: Michael S. Booth (mike@turtlerockstudios.com), January 2003

#ifndef _NAV_AREA_H_
#define _NAV_AREA_H_

#include "nav_ladder.h"
#include "tier1/memstack.h"

// BOTPORT: Clean up relationship between team index and danger storage in nav areas
enum { MAX_NAV_TEAMS = 2 };


class CFuncElevator;
class CFuncNavPrerequisite;
class CFuncNavCost;

class CNavVectorNoEditAllocator
{
public:
	CNavVectorNoEditAllocator();

	static void Reset();
	static void *Alloc( size_t nSize );
	static void *Realloc( void *pMem, size_t nSize );
	static void Free( void *pMem );
	static size_t GetSize( void *pMem );

private:
	static CMemoryStack m_memory;
	static void *m_pCurrent;
	static int m_nBytesCurrent;
};

#if !defined(_X360)
typedef CUtlVectorUltraConservativeAllocator CNavVectorAllocator;
#else
typedef CNavVectorNoEditAllocator CNavVectorAllocator;
#endif


//-------------------------------------------------------------------------------------------------------------------
/**
 * Functor interface for iteration
 */
class IForEachNavArea
{
public:
	virtual bool Inspect( const CNavArea *area ) = 0;				// Invoked once on each area of the iterated set. Return false to stop iterating.
	virtual void PostIteration( bool wasCompleteIteration ) { }		// Invoked after the iteration has ended. 'wasCompleteIteration' will be true if the entire set was iterated (ie: Inspect() never returned false)
};


//-------------------------------------------------------------------------------------------------------------------
/**
 * The NavConnect union is used to refer to connections to areas
 */
struct NavConnect
{
	NavConnect()
	{
		id = 0;
		length = -1;
	}

	union
	{
		unsigned int id;
		CNavArea *area;
	};

	mutable float length;

	bool operator==( const NavConnect &other ) const
	{
		return (area == other.area) ? true : false;
	}
};

typedef CUtlVectorUltraConservative<NavConnect, CNavVectorAllocator> NavConnectVector;


//-------------------------------------------------------------------------------------------------------------------
/**
 * The NavLadderConnect union is used to refer to connections to ladders
 */
union NavLadderConnect
{
	unsigned int id;
	CNavLadder *ladder;

	bool operator==( const NavLadderConnect &other ) const
	{
		return (ladder == other.ladder) ? true : false;
	}
};
typedef CUtlVectorUltraConservative<NavLadderConnect, CNavVectorAllocator> NavLadderConnectVector;


//--------------------------------------------------------------------------------------------------------------
/**
 * A HidingSpot is a good place for a bot to crouch and wait for enemies
 */
class HidingSpot
{
public:
	virtual ~HidingSpot()	{ }

	enum 
	{ 
		IN_COVER			= 0x01,							// in a corner with good hard cover nearby
		GOOD_SNIPER_SPOT	= 0x02,							// had at least one decent sniping corridor
		IDEAL_SNIPER_SPOT	= 0x04,							// can see either very far, or a large area, or both
		EXPOSED				= 0x08							// spot in the open, usually on a ledge or cliff
	};

	bool HasGoodCover( void ) const			{ return (m_flags & IN_COVER) ? true : false; }	// return true if hiding spot in in cover
	bool IsGoodSniperSpot( void ) const		{ return (m_flags & GOOD_SNIPER_SPOT) ? true : false; }
	bool IsIdealSniperSpot( void ) const	{ return (m_flags & IDEAL_SNIPER_SPOT) ? true : false; }
	bool IsExposed( void ) const			{ return (m_flags & EXPOSED) ? true : false; }	

	int GetFlags( void ) const		{ return m_flags; }

	void Save( CUtlBuffer &fileBuffer, unsigned int version ) const;
	void Load( CUtlBuffer &fileBuffer, unsigned int version );
	NavErrorType PostLoad( void );

	const Vector &GetPosition( void ) const		{ return m_pos; }	// get the position of the hiding spot
	unsigned int GetID( void ) const			{ return m_id; }
	const CNavArea *GetArea( void ) const		{ return m_area; }	// return nav area this hiding spot is within

	void Mark( void )							{ m_marker = m_masterMarker; }
	bool IsMarked( void ) const					{ return (m_marker == m_masterMarker) ? true : false; }
	static void ChangeMasterMarker( void )		{ ++m_masterMarker; }


public:
	void SetFlags( int flags )				{ m_flags |= flags; }	// FOR INTERNAL USE ONLY
	void SetPosition( const Vector &pos )	{ m_pos = pos; }		// FOR INTERNAL USE ONLY

private:
	friend class CNavMesh;
	friend void ClassifySniperSpot( HidingSpot *spot );

	HidingSpot( void );										// must use factory to create

	Vector m_pos;											// world coordinates of the spot
	unsigned int m_id;										// this spot's unique ID
	unsigned int m_marker;									// this spot's unique marker
	CNavArea *m_area;										// the nav area containing this hiding spot

	unsigned char m_flags;									// bit flags

	static unsigned int m_nextID;							// used when allocating spot ID's
	static unsigned int m_masterMarker;						// used to mark spots
};
typedef CUtlVectorUltraConservative< HidingSpot * > HidingSpotVector;
extern HidingSpotVector TheHidingSpots;

extern HidingSpot *GetHidingSpotByID( unsigned int id );


//--------------------------------------------------------------------------------------------------------------
/**
 * Stores a pointer to an interesting "spot", and a parametric distance along a path
 */
struct SpotOrder
{
	float t;						// parametric distance along ray where this spot first has LOS to our path
	union
	{
		HidingSpot *spot;			// the spot to look at
		unsigned int id;			// spot ID for save/load
	};
};
typedef CUtlVector< SpotOrder > SpotOrderVector;

/**
 * This struct stores possible path segments thru a CNavArea, and the dangerous spots
 * to look at as we traverse that path segment.
 */
struct SpotEncounter
{
	NavConnect from;
	NavDirType fromDir;
	NavConnect to;
	NavDirType toDir;
	Ray path;									// the path segment
	SpotOrderVector spots;						// list of spots to look at, in order of occurrence
};
typedef CUtlVectorUltraConservative< SpotEncounter * > SpotEncounterVector;


//-------------------------------------------------------------------------------------------------------------------
/**
 * A CNavArea is a rectangular region defining a walkable area in the environment
 */

class CNavAreaCriticalData
{
protected:
	// --- Begin critical data, which is heavily hit during pathing operations and carefully arranged for cache performance [7/24/2008 tom] ---

	/* 0  */	Vector m_nwCorner;											// north-west corner position (2D mins)
	/* 12 */	Vector m_seCorner;											// south-east corner position (2D maxs)
	/* 24 */	float m_invDxCorners;
	/* 28 */	float m_invDyCorners;
	/* 32 */	float m_neZ;												// height of the implicit corner defined by (m_seCorner.x, m_nwCorner.y, m_neZ)
	/* 36 */	float m_swZ;												// height of the implicit corner defined by (m_nwCorner.x, m_seCorner.y, m_neZ)
	/* 40 */	Vector m_center;											// centroid of area

	/* 52 */	unsigned char m_playerCount[ MAX_NAV_TEAMS ];				// the number of players currently in this area

	/* 54 */	bool m_isBlocked[ MAX_NAV_TEAMS ];							// if true, some part of the world is preventing movement through this nav area

	/* 56 */	unsigned int m_marker;										// used to flag the area as visited
	/* 60 */	float m_totalCost;											// the distance so far plus an estimate of the distance left
	/* 64 */	float m_costSoFar;											// distance travelled so far

	/* 68 */	CNavArea *m_nextOpen, *m_prevOpen;							// only valid if m_openMarker == m_masterMarker
	/* 76 */	unsigned int m_openMarker;									// if this equals the current marker value, we are on the open list

	/* 80 */	int	m_attributeFlags;										// set of attribute bit flags (see NavAttributeType)

	//- connections to adjacent areas -------------------------------------------------------------------
	/* 84 */	NavConnectVector m_connect[ NUM_DIRECTIONS ];				// a list of adjacent areas for each direction
	/* 100*/	NavLadderConnectVector m_ladder[ CNavLadder::NUM_LADDER_DIRECTIONS ];	// list of ladders leading up and down from this area
	/* 108*/	NavConnectVector m_elevatorAreas;							// a list of areas reachable via elevator from this area

	/* 112*/	unsigned int m_nearNavSearchMarker;							// used in GetNearestNavArea()

	/* 116*/	CNavArea *m_parent;											// the area just prior to this on in the search path
	/* 120*/	NavTraverseType m_parentHow;								// how we get from parent to us

	/* 124*/	float m_pathLengthSoFar;									// length of path so far, needed for limiting pathfind max path length

	/* *************** 360 cache line *************** */

	/* 128*/	CFuncElevator *m_elevator;									// if non-NULL, this area is in an elevator's path. The elevator can transport us vertically to another area.

	// --- End critical data --- 
};


class CNavArea : protected CNavAreaCriticalData
{
public:
	DECLARE_CLASS_NOBASE( CNavArea )

	CNavArea( void );
	virtual ~CNavArea();
	
	virtual void OnServerActivate( void );						// (EXTEND) invoked when map is initially loaded
	virtual void OnRoundRestart( void );						// (EXTEND) invoked for each area when the round restarts
	virtual void OnRoundRestartPreEntity( void ) { }			// invoked for each area when the round restarts, but before entities are deleted and recreated
	virtual void OnEnter( CBaseCombatCharacter *who, CNavArea *areaJustLeft ) { }	// invoked when player enters this area 
	virtual void OnExit( CBaseCombatCharacter *who, CNavArea *areaJustEntered ) { }	// invoked when player exits this area 

	virtual void OnDestroyNotify( CNavArea *dead );				// invoked when given area is going away
	virtual void OnDestroyNotify( CNavLadder *dead );			// invoked when given ladder is going away

	virtual void OnEditCreateNotify( CNavArea *newArea ) { }		// invoked when given area has just been added to the mesh in edit mode
	virtual void OnEditDestroyNotify( CNavArea *deadArea ) { }		// invoked when given area has just been deleted from the mesh in edit mode
	virtual void OnEditDestroyNotify( CNavLadder *deadLadder ) { }	// invoked when given ladder has just been deleted from the mesh in edit mode

	virtual void Save( CUtlBuffer &fileBuffer, unsigned int version ) const;	// (EXTEND)
	virtual NavErrorType Load( CUtlBuffer &fileBuffer, unsigned int version, unsigned int subVersion );		// (EXTEND)
	virtual NavErrorType PostLoad( void );								// (EXTEND) invoked after all areas have been loaded - for pointer binding, etc

	virtual void SaveToSelectedSet( KeyValues *areaKey ) const;		// (EXTEND) saves attributes for the area to a KeyValues
	virtual void RestoreFromSelectedSet( KeyValues *areaKey );		// (EXTEND) restores attributes from a KeyValues

	// for interactively building or generating nav areas
	void Build( CNavNode *nwNode, CNavNode *neNode, CNavNode *seNode, CNavNode *swNode );
	void Build( const Vector &corner, const Vector &otherCorner );
	void Build( const Vector &nwCorner, const Vector &neCorner, const Vector &seCorner, const Vector &swCorner );

	void ConnectTo( CNavArea *area, NavDirType dir );			// connect this area to given area in given direction
	void Disconnect( CNavArea *area );							// disconnect this area from given area

	void ConnectTo( CNavLadder *ladder );						// connect this area to given ladder
	void Disconnect( CNavLadder *ladder );						// disconnect this area from given ladder

	unsigned int GetID( void ) const	{ return m_id; }		// return this area's unique ID
	static void CompressIDs( void );							// re-orders area ID's so they are continuous
	unsigned int GetDebugID( void ) const { return m_debugid; }

	void SetAttributes( int bits )			{ m_attributeFlags = bits; }
	int GetAttributes( void ) const			{ return m_attributeFlags; }
	bool HasAttributes( int bits ) const	{ return ( m_attributeFlags & bits ) ? true : false; }
	void RemoveAttributes( int bits )		{ m_attributeFlags &= ( ~bits ); }

	void SetPlace( Place place )		{ m_place = place; }	// set place descriptor
	Place GetPlace( void ) const		{ return m_place; }		// get place descriptor

	void MarkAsBlocked( int teamID, CBaseEntity *blocker, bool bGenerateEvent = true );	// An entity can force a nav area to be blocked
	virtual void UpdateBlocked( bool force = false, int teamID = TEAM_ANY );		// Updates the (un)blocked status of the nav area (throttled)
	virtual bool IsBlocked( int teamID, bool ignoreNavBlockers = false ) const;
	void UnblockArea( int teamID = TEAM_ANY );					// clear blocked status for the given team(s)

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

	void MarkObstacleToAvoid( float obstructionHeight );
	void UpdateAvoidanceObstacles( void );
	bool HasAvoidanceObstacle( float maxObstructionHeight = StepHeight ) const; // is there a large, immobile object obstructing this area
	float GetAvoidanceObstacleHeight( void ) const; // returns the maximum height of the obstruction above the ground

#ifdef NEXT_BOT
	bool HasPrerequisite( CBaseCombatCharacter *actor = NULL ) const;							// return true if this area has a prerequisite that applies to the given actor
	const CUtlVector< CHandle< CFuncNavPrerequisite > > &GetPrerequisiteVector( void ) const;	// return vector of prerequisites that must be met before this area can be traversed
	void RemoveAllPrerequisites( void );
	void AddPrerequisite( CFuncNavPrerequisite *prereq );
#endif

	void ClearAllNavCostEntities( void );							// clear set of func_nav_cost entities that affect this area
	void AddFuncNavCostEntity( CFuncNavCost *cost );				// add the given func_nav_cost entity to the cost of this area
	float ComputeFuncNavCost( CBaseCombatCharacter *who ) const;	// return the cost multiplier of this area's func_nav_cost entities for the given actor
	bool HasFuncNavAvoid( void ) const;
	bool HasFuncNavPrefer( void ) const;

	void CheckWaterLevel( void );
	bool IsUnderwater( void ) const		{ return m_isUnderwater; }

	bool IsOverlapping( const Vector &pos, float tolerance = 0.0f ) const;	// return true if 'pos' is within 2D extents of area.
	bool IsOverlapping( const CNavArea *area ) const;			// return true if 'area' overlaps our 2D extents
	bool IsOverlapping( const Extent &extent ) const;			// return true if 'extent' overlaps our 2D extents
	bool IsOverlappingX( const CNavArea *area ) const;			// return true if 'area' overlaps our X extent
	bool IsOverlappingY( const CNavArea *area ) const;			// return true if 'area' overlaps our Y extent
	inline float GetZ( const Vector * RESTRICT pPos ) const ;			// return Z of area at (x,y) of 'pos'
	inline float GetZ( const Vector &pos ) const;						// return Z of area at (x,y) of 'pos'
	float GetZ( float x, float y ) const RESTRICT;				// return Z of area at (x,y) of 'pos'
	bool Contains( const Vector &pos ) const;					// return true if given point is on or above this area, but no others
	bool Contains( const CNavArea *area ) const;	
	bool IsCoplanar( const CNavArea *area ) const;				// return true if this area and given area are approximately co-planar
	void GetClosestPointOnArea( const Vector * RESTRICT pPos, Vector *close ) const RESTRICT;	// return closest point to 'pos' on this area - returned point in 'close'
	void GetClosestPointOnArea( const Vector &pos, Vector *close ) const { return GetClosestPointOnArea( &pos, close ); }
	float GetDistanceSquaredToPoint( const Vector &pos ) const;	// return shortest distance between point and this area
	bool IsDegenerate( void ) const;							// return true if this area is badly formed
	bool IsRoughlySquare( void ) const;							// return true if this area is approximately square
	bool IsFlat( void ) const;									// return true if this area is approximately flat
	bool HasNodes( void ) const;
	void GetNodes( NavDirType dir, CUtlVector< CNavNode * > *nodes ) const;	// build a vector of nodes along the given direction
	CNavNode *FindClosestNode( const Vector &pos, NavDirType dir ) const;	// returns the closest node along the given edge to the given point

	bool IsContiguous( const CNavArea *other ) const;			// return true if the given area and 'other' share a colinear edge (ie: no drop-down or step/jump/climb)
	float ComputeAdjacentConnectionHeightChange( const CNavArea *destinationArea ) const;			// return height change between edges of adjacent nav areas (not actual underlying ground)

	bool IsEdge( NavDirType dir ) const;						// return true if there are no bi-directional links on the given side

	bool IsDamaging( void ) const;								// Return true if continuous damage (ie: fire) is in this area
	void MarkAsDamaging( float duration );						// Mark this area is damaging for the next 'duration' seconds

	bool IsVisible( const Vector &eye, Vector *visSpot = NULL ) const;	// return true if area is visible from the given eyepoint, return visible spot

	int GetAdjacentCount( NavDirType dir ) const	{ return m_connect[ dir ].Count(); }	// return number of connected areas in given direction
	CNavArea *GetAdjacentArea( NavDirType dir, int i ) const;	// return the i'th adjacent area in the given direction
	CNavArea *GetRandomAdjacentArea( NavDirType dir ) const;
	void CollectAdjacentAreas( CUtlVector< CNavArea * > *adjVector ) const;	// build a vector of all adjacent areas

	const NavConnectVector *GetAdjacentAreas( NavDirType dir ) const	{ return &m_connect[dir]; }
	bool IsConnected( const CNavArea *area, NavDirType dir ) const;	// return true if given area is connected in given direction
	bool IsConnected( const CNavLadder *ladder, CNavLadder::LadderDirectionType dir ) const;	// return true if given ladder is connected in given direction
	float ComputeGroundHeightChange( const CNavArea *area );			// compute change in actual ground height from this area to given area

	const NavConnectVector *GetIncomingConnections( NavDirType dir ) const	{ return &m_incomingConnect[dir]; }	// get areas connected TO this area by a ONE-WAY link (ie: we have no connection back to them)
	void AddIncomingConnection( CNavArea *source, NavDirType incomingEdgeDir );

	const NavLadderConnectVector *GetLadders( CNavLadder::LadderDirectionType dir ) const	{ return &m_ladder[dir]; }
	CFuncElevator *GetElevator( void ) const												{ Assert( !( m_attributeFlags & NAV_MESH_HAS_ELEVATOR ) == (m_elevator == NULL) ); return ( m_attributeFlags & NAV_MESH_HAS_ELEVATOR ) ? m_elevator : NULL; }
	const NavConnectVector &GetElevatorAreas( void ) const									{ return m_elevatorAreas; }	// return collection of areas reachable via elevator from this area

	void ComputePortal( const CNavArea *to, NavDirType dir, Vector *center, float *halfWidth ) const;		// compute portal to adjacent area
	NavDirType ComputeLargestPortal( const CNavArea *to, Vector *center, float *halfWidth ) const;		// compute largest portal to adjacent area, returning direction
	void ComputeClosestPointInPortal( const CNavArea *to, NavDirType dir, const Vector &fromPos, Vector *closePos ) const; // compute closest point within the "portal" between to adjacent areas
	NavDirType ComputeDirection( Vector *point ) const;			// return direction from this area to the given point

	//- for hunting algorithm ---------------------------------------------------------------------------
	void SetClearedTimestamp( int teamID );						// set this area's "clear" timestamp to now
	float GetClearedTimestamp( int teamID ) const;				// get time this area was marked "clear"

	//- hiding spots ------------------------------------------------------------------------------------
	const HidingSpotVector *GetHidingSpots( void ) const	{ return &m_hidingSpots; }

	SpotEncounter *GetSpotEncounter( const CNavArea *from, const CNavArea *to );	// given the areas we are moving between, return the spots we will encounter
	int GetSpotEncounterCount( void ) const				{ return m_spotEncounters.Count(); }

	//- "danger" ----------------------------------------------------------------------------------------
	void IncreaseDanger( int teamID, float amount );			// increase the danger of this area for the given team
	float GetDanger( int teamID );								// return the danger of this area (decays over time)
	virtual float GetDangerDecayRate( void ) const;				// return danger decay rate per second

	//- extents -----------------------------------------------------------------------------------------
	float GetSizeX( void ) const			{ return m_seCorner.x - m_nwCorner.x; }
	float GetSizeY( void ) const			{ return m_seCorner.y - m_nwCorner.y; }
	void GetExtent( Extent *extent ) const;						// return a computed extent (XY is in m_nwCorner and m_seCorner, Z is computed)
	const Vector &GetCenter( void ) const	{ return m_center; }
	Vector GetRandomPoint( void ) const;
	Vector GetCorner( NavCornerType corner ) const;
	void SetCorner( NavCornerType corner, const Vector& newPosition );
	void ComputeNormal( Vector *normal, bool alternate = false ) const;	// Computes the area's normal based on m_nwCorner.  If 'alternate' is specified, m_seCorner is used instead.
	void RemoveOrthogonalConnections( NavDirType dir );

	//- occupy time ------------------------------------------------------------------------------------
	float GetEarliestOccupyTime( int teamID ) const;			// returns the minimum time for someone of the given team to reach this spot from their spawn
	bool IsBattlefront( void ) const	{ return m_isBattlefront; }	// true if this area is a "battlefront" - where rushing teams initially meet

	//- player counting --------------------------------------------------------------------------------
	void IncrementPlayerCount( int teamID, int entIndex );		// add one player to this area's count
	void DecrementPlayerCount( int teamID, int entIndex );		// subtract one player from this area's count
	unsigned char GetPlayerCount( int teamID = 0 ) const;		// return number of players of given team currently within this area (team of zero means any/all)

	//- lighting ----------------------------------------------------------------------------------------
	float GetLightIntensity( const Vector &pos ) const;			// returns a 0..1 light intensity for the given point
	float GetLightIntensity( float x, float y ) const;			// returns a 0..1 light intensity for the given point
	float GetLightIntensity( void ) const;						// returns a 0..1 light intensity averaged over the whole area

	//- A* pathfinding algorithm ------------------------------------------------------------------------
	static void MakeNewMarker( void )	{ ++m_masterMarker; if (m_masterMarker == 0) m_masterMarker = 1; }
	void Mark( void )					{ m_marker = m_masterMarker; }
	BOOL IsMarked( void ) const			{ return (m_marker == m_masterMarker) ? true : false; }
	
	void SetParent( CNavArea *parent, NavTraverseType how = NUM_TRAVERSE_TYPES )	{ m_parent = parent; m_parentHow = how; }
	CNavArea *GetParent( void ) const	{ return m_parent; }
	NavTraverseType GetParentHow( void ) const	{ return m_parentHow; }

	bool IsOpen( void ) const;									// true if on "open list"
	void AddToOpenList( void );									// add to open list in decreasing value order
	void AddToOpenListTail( void );								// add to tail of the open list
	void UpdateOnOpenList( void );								// a smaller value has been found, update this area on the open list
	void RemoveFromOpenList( void );
	static bool IsOpenListEmpty( void );
	static CNavArea *PopOpenList( void );						// remove and return the first element of the open list													

	bool IsClosed( void ) const;								// true if on "closed list"
	void AddToClosedList( void );								// add to the closed list
	void RemoveFromClosedList( void );

	static void ClearSearchLists( void );						// clears the open and closed lists for a new search

	void SetTotalCost( float value )	{ Assert( value >= 0.0 && !IS_NAN(value) ); m_totalCost = value; }
	float GetTotalCost( void ) const	{ return m_totalCost; }

	void SetCostSoFar( float value )	{ Assert( value >= 0.0 && !IS_NAN(value) ); m_costSoFar = value; }
	float GetCostSoFar( void ) const	{ return m_costSoFar; }

	void SetPathLengthSoFar( float value )	{ Assert( value >= 0.0 && !IS_NAN(value) ); m_pathLengthSoFar = value; }
	float GetPathLengthSoFar( void ) const	{ return m_pathLengthSoFar; }

	//- editing -----------------------------------------------------------------------------------------
	virtual void Draw( void ) const;							// draw area for debugging & editing
	virtual void DrawFilled( int r, int g, int b, int a, float deltaT = 0.1f, bool noDepthTest = true, float margin = 5.0f ) const;	// draw area as a filled rect of the given color
	virtual void DrawSelectedSet( const Vector &shift ) const;	// draw this area as part of a selected set
	void DrawDragSelectionSet( Color &dragSelectionSetColor ) const;
	void DrawConnectedAreas( void ) const;
	void DrawHidingSpots( void ) const;
	bool SplitEdit( bool splitAlongX, float splitEdge, CNavArea **outAlpha = NULL, CNavArea **outBeta = NULL );	// split this area into two areas at the given edge
	bool MergeEdit( CNavArea *adj );							// merge this area and given adjacent area 
	bool SpliceEdit( CNavArea *other );							// create a new area between this area and given area 
	void RaiseCorner( NavCornerType corner, int amount, bool raiseAdjacentCorners = true );	// raise/lower a corner (or all corners if corner == NUM_CORNERS)
	void PlaceOnGround( NavCornerType corner, float inset = 0.0f );	// places a corner (or all corners if corner == NUM_CORNERS) on the ground
	NavCornerType GetCornerUnderCursor( void ) const;
	bool GetCornerHotspot( NavCornerType corner, Vector hotspot[NUM_CORNERS] ) const;	// returns true if the corner is under the cursor
	void Shift( const Vector &shift );							// shift the nav area

	//- ladders -----------------------------------------------------------------------------------------
	void AddLadderUp( CNavLadder *ladder );
	void AddLadderDown( CNavLadder *ladder );

	//- generation and analysis -------------------------------------------------------------------------
	virtual void ComputeHidingSpots( void );					// analyze local area neighborhood to find "hiding spots" in this area - for map learning
	virtual void ComputeSniperSpots( void );					// analyze local area neighborhood to find "sniper spots" in this area - for map learning
	virtual void ComputeSpotEncounters( void );					// compute spot encounter data - for map learning
	virtual void ComputeEarliestOccupyTimes( void );
	virtual void CustomAnalysis( bool isIncremental = false ) { }	// for game-specific analysis
	virtual bool ComputeLighting( void );						// compute 0..1 light intensity at corners and center (requires client via listenserver)
	bool TestStairs( void );									// Test an area for being on stairs
	virtual bool IsAbleToMergeWith( CNavArea *other ) const;

	virtual void InheritAttributes( CNavArea *first, CNavArea *second = NULL );


	//- visibility -------------------------------------------------------------------------------------
	enum VisibilityType
	{
		NOT_VISIBLE				= 0x00,
		POTENTIALLY_VISIBLE		= 0x01,
		COMPLETELY_VISIBLE		= 0x02,
	};

	VisibilityType ComputeVisibility( const CNavArea *area, bool isPVSValid, bool bCheckPVS = true, bool *pOutsidePVS = NULL ) const;	// do actual line-of-sight traces to determine if any part of given area is visible from this area
	void SetupPVS( void ) const;
	bool IsInPVS( void ) const;					// return true if this area is within the current PVS

	struct AreaBindInfo							// for pointer loading and binding
	{
		union
		{
			CNavArea *area;
			unsigned int id;
		};

		unsigned char attributes;				// VisibilityType

		bool operator==( const AreaBindInfo &other ) const
		{
			return ( area == other.area );
		}
	};

	virtual bool IsEntirelyVisible( const Vector &eye, CBaseEntity *ignore = NULL ) const;				// return true if entire area is visible from given eyepoint (CPU intensive)
	virtual bool IsPartiallyVisible( const Vector &eye, CBaseEntity *ignore = NULL ) const;				// return true if any portion of the area is visible from given eyepoint (CPU intensive)

	virtual bool IsPotentiallyVisible( const CNavArea *area ) const;		// return true if given area is potentially visible from somewhere in this area (very fast)
	virtual bool IsPotentiallyVisibleToTeam( int team ) const;				// return true if any portion of this area is visible to anyone on the given team (very fast)

	virtual bool IsCompletelyVisible( const CNavArea *area ) const;			// return true if given area is completely visible from somewhere in this area (very fast)
	virtual bool IsCompletelyVisibleToTeam( int team ) const;				// return true if given area is completely visible from somewhere in this area by someone on the team (very fast)

	//-------------------------------------------------------------------------------------
	/**
	 * Apply the functor to all navigation areas that are potentially
	 * visible from this area.
	 */
	template < typename Functor >
	bool ForAllPotentiallyVisibleAreas( Functor &func )
	{
		int i;

		++s_nCurrVisTestCounter;

		for ( i=0; i<m_potentiallyVisibleAreas.Count(); ++i )
		{
			CNavArea *area = m_potentiallyVisibleAreas[i].area;
			if ( !area )
				continue;

			// If this assertion triggers, an area is in here twice!
			Assert( area->m_nVisTestCounter != s_nCurrVisTestCounter );
			area->m_nVisTestCounter = s_nCurrVisTestCounter;

			if ( m_potentiallyVisibleAreas[i].attributes == NOT_VISIBLE )
				continue;
			
			if ( func( area ) == false )
				return false;
		}

		// for each inherited area
		if ( !m_inheritVisibilityFrom.area )
			return true;

		CAreaBindInfoArray &inherited = m_inheritVisibilityFrom.area->m_potentiallyVisibleAreas;

		for ( i=0; i<inherited.Count(); ++i )
		{
			if ( !inherited[i].area )
				continue;

			// We may have visited this from m_potentiallyVisibleAreas
			if ( inherited[i].area->m_nVisTestCounter == s_nCurrVisTestCounter )
				continue;

			// Theoretically, this shouldn't matter. But, just in case!
			inherited[i].area->m_nVisTestCounter = s_nCurrVisTestCounter;

			if ( inherited[i].attributes == NOT_VISIBLE )
				continue;

			if ( func( inherited[i].area ) == false )
				return false;
		}

		return true;
	}

	//-------------------------------------------------------------------------------------
	/**
	 * Apply the functor to all navigation areas that are
	 * completely visible from somewhere in this area.
	 */
	template < typename Functor >
	bool ForAllCompletelyVisibleAreas( Functor &func )
	{
		int i;

		++s_nCurrVisTestCounter;

		for ( i=0; i<m_potentiallyVisibleAreas.Count(); ++i )
		{
			CNavArea *area = m_potentiallyVisibleAreas[i].area;
			if ( !area )
				continue;

			// If this assertion triggers, an area is in here twice!
			Assert( area->m_nVisTestCounter != s_nCurrVisTestCounter );
			area->m_nVisTestCounter = s_nCurrVisTestCounter;

			if ( ( m_potentiallyVisibleAreas[i].attributes & COMPLETELY_VISIBLE ) == 0 )
				continue;

			if ( func( area ) == false )
				return false;
		}

		if ( !m_inheritVisibilityFrom.area )
			return true;

		// for each inherited area
		CAreaBindInfoArray &inherited = m_inheritVisibilityFrom.area->m_potentiallyVisibleAreas;

		for ( i=0; i<inherited.Count(); ++i )
		{
			if ( !inherited[i].area )
				continue;
			
			// We may have visited this from m_potentiallyVisibleAreas
			if ( inherited[i].area->m_nVisTestCounter == s_nCurrVisTestCounter )
				continue;

			// Theoretically, this shouldn't matter. But, just in case!
			inherited[i].area->m_nVisTestCounter = s_nCurrVisTestCounter;

			if ( ( inherited[i].attributes & COMPLETELY_VISIBLE ) == 0 )
				continue;

			if ( func( inherited[i].area ) == false )
				return false;
		}

		return true;
	}


private:
	friend class CNavMesh;
	friend class CNavLadder;
	friend class CCSNavArea;									// allow CS load code to complete replace our default load behavior

	static bool m_isReset;										// if true, don't bother cleaning up in destructor since everything is going away

	/*
	m_nwCorner
		nw           ne
		 +-----------+
		 | +-->x     |
		 | |         |
		 | v         |
		 | y         |
		 |           |
		 +-----------+
		sw           se
					m_seCorner
	*/

	static unsigned int m_nextID;								// used to allocate unique IDs
	unsigned int m_id;											// unique area ID
	unsigned int m_debugid;

	Place m_place;												// place descriptor

	CountdownTimer m_blockedTimer;								// Throttle checks on our blocked state while blocked
	void UpdateBlockedFromNavBlockers( void );					// checks if nav blockers are still blocking the area

	bool m_isUnderwater;										// true if the center of the area is underwater

	bool m_isBattlefront;

	float m_avoidanceObstacleHeight;							// if nonzero, a prop is obstructing movement through this nav area
	CountdownTimer m_avoidanceObstacleTimer;					// Throttle checks on our obstructed state while obstructed

	//- for hunting -------------------------------------------------------------------------------------
	float m_clearedTimestamp[ MAX_NAV_TEAMS ];					// time this area was last "cleared" of enemies

	//- "danger" ----------------------------------------------------------------------------------------
	float m_danger[ MAX_NAV_TEAMS ];							// danger of this area, allowing bots to avoid areas where they died in the past - zero is no danger
	float m_dangerTimestamp[ MAX_NAV_TEAMS ];					// time when danger value was set - used for decaying
	void DecayDanger( void );

	//- hiding spots ------------------------------------------------------------------------------------
	HidingSpotVector m_hidingSpots;
	bool IsHidingSpotCollision( const Vector &pos ) const;		// returns true if an existing hiding spot is too close to given position

	//- encounter spots ---------------------------------------------------------------------------------
	SpotEncounterVector m_spotEncounters;						// list of possible ways to move thru this area, and the spots to look at as we do
	void AddSpotEncounters( const CNavArea *from, NavDirType fromDir, const CNavArea *to, NavDirType toDir );	// add spot encounter data when moving from area to area

	float m_earliestOccupyTime[ MAX_NAV_TEAMS ];				// min time to reach this spot from spawn

#ifdef DEBUG_AREA_PLAYERCOUNTS
	CUtlVector< int > m_playerEntIndices[ MAX_NAV_TEAMS ];
#endif

	//- lighting ----------------------------------------------------------------------------------------
	float m_lightIntensity[ NUM_CORNERS ];						// 0..1 light intensity at corners

	//- A* pathfinding algorithm ------------------------------------------------------------------------
	static unsigned int m_masterMarker;

	static CNavArea *m_openList;
	static CNavArea *m_openListTail;

	//- connections to adjacent areas -------------------------------------------------------------------
	NavConnectVector m_incomingConnect[ NUM_DIRECTIONS ];		// a list of adjacent areas for each direction that connect TO us, but we have no connection back to them

	//---------------------------------------------------------------------------------------------------
	CNavNode *m_node[ NUM_CORNERS ];							// nav nodes at each corner of the area

	void ResetNodes( void );									// nodes are going away as part of an incremental nav generation
	void Strip( void );											// remove "analyzed" data from nav area

	void FinishMerge( CNavArea *adjArea );						// recompute internal data once nodes have been adjusted during merge
	void MergeAdjacentConnections( CNavArea *adjArea );			// for merging with "adjArea" - pick up all of "adjArea"s connections
	void AssignNodes( CNavArea *area );							// assign internal nodes to the given area

	void FinishSplitEdit( CNavArea *newArea, NavDirType ignoreEdge );	// given the portion of the original area, update its internal data

	void CalcDebugID();

#ifdef NEXT_BOT
	CUtlVector< CHandle< CFuncNavPrerequisite > > m_prerequisiteVector;		// list of prerequisites that must be met before this area can be traversed
#endif

	CNavArea *m_prevHash, *m_nextHash;							// for hash table in CNavMesh

	void ConnectElevators( void );								// find elevator connections between areas

	int m_damagingTickCount;									// this area is damaging through this tick count


	//- visibility --------------------------------------------------------------------------------------
	void ComputeVisibilityToMesh( void );						// compute visibility to surrounding mesh
	void ResetPotentiallyVisibleAreas();
	static void ComputeVisToArea( CNavArea *&pOtherArea );

#ifndef _X360
	typedef CUtlVectorConservative<AreaBindInfo> CAreaBindInfoArray; // shaves 8 bytes off structure caused by need to support editing
#else
	typedef CUtlVector<AreaBindInfo> CAreaBindInfoArray; // Need to use this on 360 to support external allocation pattern
#endif

	AreaBindInfo m_inheritVisibilityFrom;						// if non-NULL, m_potentiallyVisibleAreas becomes a list of additions and deletions (NOT_VISIBLE) to the list of this area
	CAreaBindInfoArray m_potentiallyVisibleAreas;				// list of areas potentially visible from inside this area (after PostLoad(), use area portion of union)
	bool m_isInheritedFrom;										// latch used during visibility inheritance computation

	const CAreaBindInfoArray &ComputeVisibilityDelta( const CNavArea *other ) const;	// return a list of the delta between our visibility list and the given adjacent area

	uint32 m_nVisTestCounter;
	static uint32 s_nCurrVisTestCounter;

	CUtlVector< CHandle< CFuncNavCost > > m_funcNavCostVector;	// active, overlapping cost entities
};

typedef CUtlVector< CNavArea * > NavAreaVector;
extern NavAreaVector TheNavAreas;


//--------------------------------------------------------------------------------------------------------------
//--------------------------------------------------------------------------------------------------------------
//
// Inlines
//

#ifdef NEXT_BOT

//--------------------------------------------------------------------------------------------------------------
inline bool CNavArea::HasPrerequisite( CBaseCombatCharacter *actor ) const
{
	return m_prerequisiteVector.Count() > 0;
}

//--------------------------------------------------------------------------------------------------------------
inline const CUtlVector< CHandle< CFuncNavPrerequisite > > &CNavArea::GetPrerequisiteVector( void ) const
{
	return m_prerequisiteVector;
}

//--------------------------------------------------------------------------------------------------------------
inline void CNavArea::RemoveAllPrerequisites( void )
{
	m_prerequisiteVector.RemoveAll();
}

//--------------------------------------------------------------------------------------------------------------
inline void CNavArea::AddPrerequisite( CFuncNavPrerequisite *prereq )
{
	if ( m_prerequisiteVector.Find( prereq ) == m_prerequisiteVector.InvalidIndex() )
	{
		m_prerequisiteVector.AddToTail( prereq );
	}
}
#endif

//--------------------------------------------------------------------------------------------------------------
inline float CNavArea::GetDangerDecayRate( void ) const
{
	// one kill == 1.0, which we will forget about in two minutes
	return 1.0f / 120.0f;
}

//--------------------------------------------------------------------------------------------------------------
inline bool CNavArea::IsDegenerate( void ) const
{
	return (m_nwCorner.x >= m_seCorner.x || m_nwCorner.y >= m_seCorner.y);
}

//--------------------------------------------------------------------------------------------------------------
inline CNavArea *CNavArea::GetAdjacentArea( NavDirType dir, int i ) const
{
	for( int iter = 0; iter < m_connect[dir].Count(); ++iter )
	{
		if (i == 0)
			return m_connect[dir][iter].area;
		--i;
	}

	return NULL;
}

//--------------------------------------------------------------------------------------------------------------
inline bool CNavArea::IsOpen( void ) const
{
	return (m_openMarker == m_masterMarker) ? true : false;
}

//--------------------------------------------------------------------------------------------------------------
inline bool CNavArea::IsOpenListEmpty( void )
{
	Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == NULL );
	return (m_openList) ? false : true;
}

//--------------------------------------------------------------------------------------------------------------
inline CNavArea *CNavArea::PopOpenList( void )
{
	Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == NULL );

	if ( m_openList )
	{
		CNavArea *area = m_openList;
	
		// disconnect from list
		area->RemoveFromOpenList();
		area->m_prevOpen = NULL;
		area->m_nextOpen = NULL;

		Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == NULL );

		return area;
	}

	Assert( (m_openList && m_openList->m_prevOpen == NULL) || m_openList == NULL );

	return NULL;
}

//--------------------------------------------------------------------------------------------------------------
inline bool CNavArea::IsClosed( void ) const
{
	if (IsMarked() && !IsOpen())
		return true;

	return false;
}

//--------------------------------------------------------------------------------------------------------------
inline void CNavArea::AddToClosedList( void )
{
	Mark();
}

//--------------------------------------------------------------------------------------------------------------
inline void CNavArea::RemoveFromClosedList( void )
{
	// since "closed" is defined as visited (marked) and not on open list, do nothing
}

//--------------------------------------------------------------------------------------------------------------
inline void CNavArea::SetClearedTimestamp( int teamID )
{
	m_clearedTimestamp[ teamID % MAX_NAV_TEAMS ] = gpGlobals->curtime;
}

//--------------------------------------------------------------------------------------------------------------
inline float CNavArea::GetClearedTimestamp( int teamID ) const
{ 
	return m_clearedTimestamp[ teamID % MAX_NAV_TEAMS ];
}

//--------------------------------------------------------------------------------------------------------------
inline float CNavArea::GetEarliestOccupyTime( int teamID ) const
{
	return m_earliestOccupyTime[ teamID % MAX_NAV_TEAMS ];
}


//--------------------------------------------------------------------------------------------------------------
inline bool CNavArea::IsDamaging( void ) const
{
	return ( gpGlobals->tickcount <= m_damagingTickCount );
}


//--------------------------------------------------------------------------------------------------------------
inline void CNavArea::MarkAsDamaging( float duration )
{
	m_damagingTickCount = gpGlobals->tickcount + TIME_TO_TICKS( duration );
}


//--------------------------------------------------------------------------------------------------------------
inline bool CNavArea::HasAvoidanceObstacle( float maxObstructionHeight ) const
{
	return m_avoidanceObstacleHeight > maxObstructionHeight;
}


//--------------------------------------------------------------------------------------------------------------
inline float CNavArea::GetAvoidanceObstacleHeight( void ) const
{
	return m_avoidanceObstacleHeight;
}


//--------------------------------------------------------------------------------------------------------------
inline bool CNavArea::IsVisible( const Vector &eye, Vector *visSpot ) const
{
	Vector corner;
	trace_t result;
	CTraceFilterNoNPCsOrPlayer traceFilter( NULL, COLLISION_GROUP_NONE );
	const float offset = 0.75f * HumanHeight;

	// check center first
	UTIL_TraceLine( eye, GetCenter() + Vector( 0, 0, offset ), MASK_BLOCKLOS_AND_NPCS|CONTENTS_IGNORE_NODRAW_OPAQUE, &traceFilter, &result );
	if (result.fraction == 1.0f)
	{
		// we can see this area
		if (visSpot)
		{
			*visSpot = GetCenter();
		}
		return true;
	}

	for( int c=0; c<NUM_CORNERS; ++c )
	{
		corner = GetCorner( (NavCornerType)c );
		UTIL_TraceLine( eye, corner + Vector( 0, 0, offset ), MASK_BLOCKLOS_AND_NPCS|CONTENTS_IGNORE_NODRAW_OPAQUE, &traceFilter, &result );
		if (result.fraction == 1.0f)
		{
			// we can see this area
			if (visSpot)
			{
				*visSpot = corner;
			}
			return true;
		}
	}

	return false;
}

#ifndef DEBUG_AREA_PLAYERCOUNTS
inline void CNavArea::IncrementPlayerCount( int teamID, int entIndex )
{
	teamID = teamID % MAX_NAV_TEAMS;

	if (m_playerCount[ teamID ] == 255)
	{
		DevMsg( "CNavArea::IncrementPlayerCount: Overflow\n" );
		return;
	}

	++m_playerCount[ teamID ];
}

inline void CNavArea::DecrementPlayerCount( int teamID, int entIndex )
{
	teamID = teamID % MAX_NAV_TEAMS;

	if (m_playerCount[ teamID ] == 0)
	{
		DevMsg( "CNavArea::IncrementPlayerCount: Underflow\n" );
		return;
	}

	--m_playerCount[ teamID ];
}
#endif // !DEBUG_AREA_PLAYERCOUNTS

inline unsigned char CNavArea::GetPlayerCount( int teamID ) const
{
	if (teamID)
	{
		return m_playerCount[ teamID % MAX_NAV_TEAMS ];
	}

	// sum all players
	unsigned char total = 0;
	for( int i=0; i<MAX_NAV_TEAMS; ++i )
	{
		total += m_playerCount[i];
	}

	return total;
}

//--------------------------------------------------------------------------------------------------------------
/**
* Return Z of area at (x,y) of 'pos'
* Trilinear interpolation of Z values at quad edges.
* NOTE: pos->z is not used.
*/
inline float CNavArea::GetZ( const Vector * RESTRICT pos ) const RESTRICT
{
	return GetZ( pos->x, pos->y );
}

inline float CNavArea::GetZ( const Vector & pos ) const RESTRICT
{
	return GetZ( pos.x, pos.y );
}

//--------------------------------------------------------------------------------------------------------------
/**
* Return the coordinates of the area's corner.
*/
inline Vector CNavArea::GetCorner( NavCornerType corner ) const
{
	// @TODO: Confirm compiler does the "right thing" in release builds, or change this function to to take a pointer [2/4/2009 tom]
	Vector pos;

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

	case NORTH_EAST:
		pos.x = m_seCorner.x;
		pos.y = m_nwCorner.y;
		pos.z = m_neZ;
		return pos;

	case SOUTH_WEST:
		pos.x = m_nwCorner.x;
		pos.y = m_seCorner.y;
		pos.z = m_swZ;
		return pos;

	case SOUTH_EAST:
		return m_seCorner;
	}
}


#endif // _NAV_AREA_H_