GeneralsZeroHour/Generals/Code/GameEngine/Source/GameLogic/AI/AIPathfind.cpp

/*
**	Command & Conquer Generals(tm)
**	Copyright 2025 Electronic Arts Inc.
**
**	This program is free software: you can redistribute it and/or modify
**	it under the terms of the GNU General Public License as published by
**	the Free Software Foundation, either version 3 of the License, or
**	(at your option) any later version.
**
**	This program is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**	GNU General Public License for more details.
**
**	You should have received a copy of the GNU General Public License
**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

////////////////////////////////////////////////////////////////////////////////
//																																						//
//  (c) 2001-2003 Electronic Arts Inc.																				//
//																																						//
////////////////////////////////////////////////////////////////////////////////

// AIPathfind.cpp
// AI pathfinding system
// Author: Michael S. Booth, October 2001
#include "PreRTS.h"	// This must go first in EVERY cpp file int the GameEngine

#include "GameLogic/AIPathfind.h"

#include "Common/PerfTimer.h"
#include "Common/Player.h"
#include "Common/CRCDebug.h"
#include "Common/GlobalData.h"
#include "Common/LatchRestore.h"	 
#include "Common/ThingTemplate.h"
#include "Common/ThingFactory.h"							 

#include "GameClient/Line2D.h"

#include "GameLogic/AI.h"
#include "GameLogic/GameLogic.h"
#include "GameLogic/Locomotor.h"
#include "GameLogic/Module/ContainModule.h"
#include "GameLogic/Module/AIUpdate.h"
#include "GameLogic/Module/PhysicsUpdate.h"
#include "GameLogic/Object.h"
#include "GameLogic/PartitionManager.h"
#include "GameLogic/TerrainLogic.h"
#include "GameLogic/Weapon.h"

#include "Common/UnitTimings.h" //Contains the DO_UNIT_TIMINGS define jba.	


#define no_INTENSE_DEBUG

#define DEBUG_QPF

#ifdef INTENSE_DEBUG
#include "GameLogic/ScriptEngine.h"
#endif

#include "Common/Xfer.h"
#include "Common/XferCRC.h"

//------------------------------------------------------------------------------ Performance Timers 
#include "Common/PerfMetrics.h"
#include "Common/PerfTimer.h"

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


#ifdef _INTERNAL
// for occasional debugging...
//#pragma optimize("", off)
//#pragma MESSAGE("************************************** WARNING, optimization disabled for debugging purposes")
#endif

struct TCheckMovementInfo
{
	// Input
	ICoord2D					cell;
	PathfindLayerEnum layer;
	Int								radius;	
	Bool							centerInCell;
	Bool							considerTransient;
	LocomotorSurfaceTypeMask acceptableSurfaces;
	// Output 
	Int								allyFixedCount;
	Bool							enemyFixed;
	Bool							allyMoving;
	Bool							allyGoal;
};

inline Int IABS(Int x) {	if (x>=0) return x; return -x;};

//-----------------------------------------------------------------------------------
static Int frameToShowObstacles;

//-----------------------------------------------------------------------------------
PathNode::PathNode() :
	m_nextOpti(0),
	m_next(0),
	m_prev(0),
	m_nextOptiDist2D(0),
	m_canOptimize(false),
	m_id(-1)
{
	m_nextOptiDirNorm2D.x = 0;
	m_nextOptiDirNorm2D.y = 0;
	m_pos.zero();
	m_layer = LAYER_INVALID;
}

//-----------------------------------------------------------------------------------
PathNode::~PathNode()
{
}
								 
//-----------------------------------------------------------------------------------
void PathNode::setNextOptimized(PathNode *node)
{
	m_nextOpti = node;
	if (node)
	{
		m_nextOptiDirNorm2D.x = node->getPosition()->x - getPosition()->x;
		m_nextOptiDirNorm2D.y = node->getPosition()->y - getPosition()->y;
		m_nextOptiDist2D = m_nextOptiDirNorm2D.length();
		if (m_nextOptiDist2D == 0.0f) 
		{
			//DEBUG_LOG(("Warning - Path Seg length == 0, adjusting. john a.\n"));
			m_nextOptiDist2D = 0.01f;
		}
		m_nextOptiDirNorm2D.x /= m_nextOptiDist2D;
		m_nextOptiDirNorm2D.y /= m_nextOptiDist2D;
	}
	else
	{
		m_nextOptiDist2D = 0;
	}
}

//-----------------------------------------------------------------------------------
/// given a list, prepend this node, return new list
PathNode *PathNode::prependToList( PathNode *list ) 
{ 
	m_next = list; 
	if (list)
		list->m_prev = this;
	m_prev = NULL; 
	return this; 
}

//-----------------------------------------------------------------------------------
/// given a list, append this node, return new list.  slow implementation.
/// @todo optimize this
PathNode *PathNode::appendToList( PathNode *list ) 
{ 
	if (list == NULL)
	{
		m_next = NULL;
		m_prev = NULL;
		return this;
	}

	PathNode *tail;
	for( tail = list; tail->m_next; tail = tail->m_next )
		;

	tail->m_next = this;
	m_prev = tail;
	m_next = NULL;

	return list; 
}

//-----------------------------------------------------------------------------------
/// given a node, append new node to this.
void PathNode::append( PathNode *newNode ) 
{ 
	newNode->m_next = this->m_next;	
	newNode->m_prev = this;
	if (newNode->m_next) {
		newNode->m_next->m_prev = newNode;
	}
	this->m_next = newNode;

}

//-----------------------------------------------------------------------------------
/**
 * Compute direction vector to next node
 */
const Coord3D *PathNode::computeDirectionVector( void )
{
	static Coord3D dir;

	if (m_next == NULL)
	{
		if (m_prev == NULL)
		{
			// only one node on whole path - no direction
			dir.x = 0.0f;
			dir.y = 0.0f;
			dir.z = 0.0f;
		}
		else
		{
			// tail node - continue prior direction
			return m_prev->computeDirectionVector();
		}
	}
	else
	{
		dir.x = m_next->m_pos.x - m_pos.x;
		dir.y = m_next->m_pos.y - m_pos.y;
		dir.z = m_next->m_pos.z - m_pos.z;
	}

	return &dir;
}


//-----------------------------------------------------------------------------------
Path::Path():
m_path(NULL),
m_pathTail(NULL),
m_isOptimized(FALSE), 
m_blockedByAlly(FALSE),
m_cpopRecentStart(NULL),
m_cpopCountdown(MAX_CPOP),
m_cpopValid(FALSE)
{
	m_cpopIn.zero();
	m_cpopOut.distAlongPath=0;
	m_cpopOut.layer = LAYER_GROUND;
	m_cpopOut.posOnPath.zero();
}

Path::~Path( void )
{
	PathNode *node, *nextNode;

	// delete all of the path nodes	
	for( node = m_path; node; node = nextNode )
	{
		nextNode = node->getNext();
		node->deleteInstance();
	}
}

// ------------------------------------------------------------------------------------------------
/** CRC */
// ------------------------------------------------------------------------------------------------
void Path::crc( Xfer *xfer )
{
}  // end crc

// ------------------------------------------------------------------------------------------------
/** Xfer Method */
// ------------------------------------------------------------------------------------------------
void Path::xfer( Xfer *xfer )
{
  // version
  XferVersion currentVersion = 1;
  XferVersion version = currentVersion;
  xfer->xferVersion( &version, currentVersion );

	PathNode *node = m_path;
	Int count = 0;
	while (node) {
		count++;
		node = node->getNext();
	}
	xfer->xferInt(&count);

	if (xfer->getXferMode() == XFER_SAVE)	{	
		node = m_pathTail;  // Write them out backwards.
		while (node) {
			node->m_id = count;
			xfer->xferInt(&count);
			Coord3D pos = *node->getPosition();
			xfer->xferCoord3D(&pos);
			PathfindLayerEnum layer = node->getLayer();
			xfer->xferUser(&layer, sizeof(layer));
			Bool canOpt = node->getCanOptimize();
			xfer->xferBool(&canOpt);
			Int id = -1;
			if (node->getNextOptimized()) {
				id = node->getNextOptimized()->m_id;
			}
			xfer->xferInt(&id);
			count--; 
			node = node->getPrevious();
		}
		DEBUG_ASSERTCRASH(count==0, ("Wrong data count"));
	} else {
		m_cpopValid = FALSE;
		while (count) {
			Int nodeId;
			xfer->xferInt(&nodeId);
			DEBUG_ASSERTCRASH(nodeId==count, ("Bad data"));
			Coord3D pos;
			xfer->xferCoord3D(&pos);
			PathfindLayerEnum layer;
			xfer->xferUser(&layer, sizeof(layer));
			Bool canOpt;
			xfer->xferBool(&canOpt);
			Int optID = -1;
			xfer->xferInt(&optID);
			PathNode *node = newInstance(PathNode);
			node->m_id = nodeId;
			node->setPosition(&pos);
			node->setLayer(layer);
			node->setCanOptimize(canOpt);
			PathNode *optNode = NULL;
			if (optID > 0) {
				optNode = m_path;
				while (optNode && optNode->m_id != optID) {
					optNode = optNode->getNext();
				}
				DEBUG_ASSERTCRASH (optNode && optNode->m_id == optID, ("Could not find optimized link."));
			}
			m_path = node->prependToList(m_path);
			if (m_pathTail == NULL)
				m_pathTail = node;
			if (optNode) {
				node->setNextOptimized(optNode);
			}
			count--;
		}
	}

	xfer->xferBool(&m_isOptimized);
	Int obsolete1 = 0;
	xfer->xferInt(&obsolete1);	
	UnsignedInt obsolete2;
	xfer->xferUnsignedInt(&obsolete2);
	xfer->xferBool(&m_blockedByAlly);


#if defined _DEBUG || defined _INTERNAL
	if (TheGlobalData->m_debugAI == AI_DEBUG_PATHS)
	{
		extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 		RGBColor color;
		color.blue = 0;
		color.red = color.green = 1;
		Coord3D pos;
		addIcon(NULL, 0, 0, color); // erase feedback.
		for( PathNode *node = getFirstNode(); node; node = node->getNext() )
		{

			// create objects to show path - they decay

			pos = *node->getPosition();
			addIcon(&pos, PATHFIND_CELL_SIZE_F*.25f, 200, color);
		}

		// show optimized path
		for( node = getFirstNode(); node; node = node->getNextOptimized() )
		{
			pos = *node->getPosition();
			addIcon(&pos, PATHFIND_CELL_SIZE_F*.8f, 200, color);
		}
		TheAI->pathfinder()->setDebugPath(this);
	}
#endif
}  // end xfer

// ------------------------------------------------------------------------------------------------
/** Load post process */
// ------------------------------------------------------------------------------------------------
void Path::loadPostProcess( void )
{
}  // end loadPostProcess

/**
 * Create a new node at the head of the path
 */
void Path::prependNode( const Coord3D *pos, PathfindLayerEnum layer )
{
	PathNode *node = newInstance(PathNode);

	node->setPosition( pos );
	node->setLayer(layer);

	m_path = node->prependToList( m_path );

	if (m_pathTail == NULL)
		m_pathTail = node;

	m_isOptimized = false;

#ifdef CPOP_STARTS_FROM_PREV_SEG
	m_cpopRecentStart = NULL;
#endif
}

/**
 * Create a new node at the tail of the path
 */
void Path::appendNode( const Coord3D *pos, PathfindLayerEnum layer )
{
	if (m_isOptimized && m_pathTail) 
	{
		/* Check for duplicates. */
		if (pos->x == m_pathTail->getPosition()->x && pos->y == m_pathTail->getPosition()->y) {
			DEBUG_LOG(("Warning - Path Seg length == 0, ignoring. john a.\n"));
			return;
		}
	}
	PathNode *node = newInstance(PathNode);

	node->setPosition( pos );
	node->setLayer(layer);

	m_path = node->appendToList( m_path );

	if (m_isOptimized && m_pathTail) 
	{
		m_pathTail->setNextOptimized(node);
	}

	m_pathTail = node;

#ifdef CPOP_STARTS_FROM_PREV_SEG
	m_cpopRecentStart = NULL;
#endif
}
/**
 * Create a new node at the tail of the path
 */
void Path::updateLastNode( const Coord3D *pos )
{
	PathfindLayerEnum layer = TheTerrainLogic->getLayerForDestination(pos);
	if (m_pathTail) {
		m_pathTail->setPosition(pos);
		m_pathTail->setLayer(layer);
	}
	if (m_isOptimized && m_pathTail) 
	{
		PathNode *node = m_path;
		while(node && node->getNextOptimized() != m_pathTail) {
			node = node->getNextOptimized();
		}
		if (node && node->getNextOptimized() == m_pathTail) {
			node->setNextOptimized(m_pathTail);
		}
	}
}

/**
 * Optimize the path by checking line of sight
 */
void Path::optimize( const Object *obj, LocomotorSurfaceTypeMask acceptableSurfaces, Bool blocked )
{
	PathNode *node, *anchor;

	// start with first node in the path
	anchor = getFirstNode();

	Bool firstNode = true;
	PathfindLayerEnum firstLayer = anchor->getLayer();

	// backwards.

	//
	// For each node in the path, check LOS from last node in path, working forward.
	// When a clear LOS is found, keep the resulting straight line segment.
	//
	while( anchor != getLastNode() )
	{
		// find the farthest node in the path that has a clear line-of-sight to this anchor
		Bool optimizedSegment = false;
		PathfindLayerEnum layer = anchor->getLayer();
		PathfindLayerEnum curLayer = anchor->getLayer();
		Int count = 0;
		const Int ALLOWED_STEPS = 3; // we can optimize 3 steps to or from a bridge.  Otherwise, we need to insert a point. jba.
		for (node = anchor->getNext(); node->getNext(); node=node->getNext()) {
			count++;
			if (curLayer==LAYER_GROUND) {
				if (node->getLayer() != curLayer) {
					layer = node->getLayer();
					curLayer = layer;
					if (count > ALLOWED_STEPS) break;
				}
			}	else {
				if (node->getNext()->getLayer() != curLayer) {
					if (count > ALLOWED_STEPS) break;
				}
			}
			curLayer = node->getLayer();
			if (node->getCanOptimize()==false) {
				break;
			}
		}
		if (firstNode) {
			layer = firstLayer;
			firstNode = false;
		}
		//PathfindLayerEnum curLayer = LAYER_GROUND;
		for( ; node != anchor; node = node->getPrevious() )		
		{
			Bool isPassable = false;
			//CRCDEBUG_LOG(("Path::optimize() calling isLinePassable()\n"));
			if (TheAI->pathfinder()->isLinePassable( obj, acceptableSurfaces, layer, *anchor->getPosition(), 
				*node->getPosition(), blocked, false))
			{
				isPassable = true;
			} 
			PathfindCell* cell = TheAI->pathfinder()->getCell( layer, node->getPosition());
			if (cell && cell->getType()==PathfindCell::CELL_CLIFF && !cell->getPinched()) {
				isPassable = true;
			}
			// Horizontal, diagonal, and vertical steps are passable.
			if (!isPassable) {
				Int dx = node->getPosition()->x - anchor->getPosition()->x;
				Int dy = node->getPosition()->y - anchor->getPosition()->y;
				Bool mightBePassable = false;
				if (IABS(dx)==PATHFIND_CELL_SIZE && IABS(dy)==PATHFIND_CELL_SIZE) {
					isPassable = true;
				}
				PathNode *tmpNode;
				if (dx==0) {
					mightBePassable = true;
					for (tmpNode = node->getPrevious(); tmpNode && tmpNode != anchor; tmpNode = tmpNode->getPrevious()) {
						dx = tmpNode->getNext()->getPosition()->x - tmpNode->getPosition()->x;
						if (dx!=0) mightBePassable = false;
					}
				}
				if (dy==0) {
					mightBePassable = true;
					for (tmpNode = node->getPrevious(); tmpNode && tmpNode != anchor; tmpNode = tmpNode->getPrevious()) {
						dy = tmpNode->getNext()->getPosition()->y - tmpNode->getPosition()->y;
						if (dy!=0) mightBePassable = false;
					}
				}
				if (dx == dy) {
					mightBePassable = true;
					for (tmpNode = node->getPrevious(); tmpNode &&   tmpNode != anchor; tmpNode = tmpNode->getPrevious()) {
						dx = tmpNode->getNext()->getPosition()->x - tmpNode->getPosition()->x;
						dy = tmpNode->getNext()->getPosition()->y - tmpNode->getPosition()->y;
						if (dy!=dx) mightBePassable = false;
					}
				}
				if (dx == -dy) {
					mightBePassable = true;
					for (tmpNode = node->getPrevious(); tmpNode &&   tmpNode != anchor; tmpNode = tmpNode->getPrevious()) {
						dx = tmpNode->getNext()->getPosition()->x - tmpNode->getPosition()->x;
						dy = tmpNode->getNext()->getPosition()->y - tmpNode->getPosition()->y;
						if (dy!=-dx) mightBePassable = false;
					}
				}
				if (mightBePassable) {
					isPassable = true;
				}
			}
			if (isPassable) 
			{
				// anchor can directly see this node, make it next in the optimized path
				anchor->setNextOptimized( node );
				anchor = node;
				optimizedSegment = true;
				break;
			}
		}
			
		if (optimizedSegment == false)
		{
			// for some reason, there is no clear LOS between the anchor node and the very next node
			anchor->setNextOptimized( anchor->getNext() );
			anchor = anchor->getNext();
		}
	}

	// the path has been optimized
	m_isOptimized = true;
}

/**
 * Optimize the path by checking line of sight
 */
void Path::optimizeGroundPath( Bool crusher, Int pathDiameter )
{
	PathNode *node, *anchor;

	// start with first node in the path
	anchor = getFirstNode();

	//
	// For each node in the path, check LOS from last node in path, working forward.
	// When a clear LOS is found, keep the resulting straight line segment.
	//
	while( anchor != getLastNode() )
	{
		// find the farthest node in the path that has a clear line-of-sight to this anchor
		Bool optimizedSegment = false;
		PathfindLayerEnum layer = anchor->getLayer();
		PathfindLayerEnum curLayer = anchor->getLayer();
		Int count = 0;
		const Int ALLOWED_STEPS = 3; // we can optimize 3 steps to or from a bridge.  Otherwise, we need to insert a point. jba.
		for (node = anchor->getNext(); node->getNext(); node=node->getNext()) {
			count++;
			if (curLayer==LAYER_GROUND) {
				if (node->getLayer() != curLayer) {
					layer = node->getLayer();
					curLayer = layer;
					if (count > ALLOWED_STEPS) break;
				}
			}	else {
				if (node->getNext()->getLayer() != curLayer) {
					if (count > ALLOWED_STEPS) break;
				}
			}
			curLayer = node->getLayer();
		}

		// find the farthest node in the path that has a clear line-of-sight to this anchor
		for( ; node != anchor; node = node->getPrevious() )		
		{
			Bool isPassable = false;
			//CRCDEBUG_LOG(("Path::optimize() calling isLinePassable()\n"));
			if (TheAI->pathfinder()->isGroundPathPassable( crusher, *anchor->getPosition(), layer,
				*node->getPosition(), pathDiameter))
			{
				isPassable = true;
			} 
			// Horizontal, diagonal, and vertical steps are passable.
			if (!isPassable) {
				Int dx = node->getPosition()->x - anchor->getPosition()->x;
				Int dy = node->getPosition()->y - anchor->getPosition()->y;
				Bool mightBePassable = false;
				PathNode *tmpNode;
				if (dx==0) {
					mightBePassable = true;
					for (tmpNode = node->getPrevious(); tmpNode && tmpNode != anchor; tmpNode = tmpNode->getPrevious()) {
						dx = tmpNode->getNext()->getPosition()->x - tmpNode->getPosition()->x;
						if (dx!=0) mightBePassable = false;
					}
				}
				if (dy==0) {
					mightBePassable = true;
					for (tmpNode = node->getPrevious(); tmpNode && tmpNode != anchor; tmpNode = tmpNode->getPrevious()) {
						dy = tmpNode->getNext()->getPosition()->y - tmpNode->getPosition()->y;
						if (dy!=0) mightBePassable = false;
					}
				}
				if (dx == dy) {
					mightBePassable = true;
					for (tmpNode = node->getPrevious(); tmpNode &&   tmpNode != anchor; tmpNode = tmpNode->getPrevious()) {
						dx = tmpNode->getNext()->getPosition()->x - tmpNode->getPosition()->x;
						dy = tmpNode->getNext()->getPosition()->y - tmpNode->getPosition()->y;
						if (dy!=dx) mightBePassable = false;
					}
				}
				if (dx == -dy) {
					mightBePassable = true;
					for (tmpNode = node->getPrevious(); tmpNode &&   tmpNode != anchor; tmpNode = tmpNode->getPrevious()) {
						dx = tmpNode->getNext()->getPosition()->x - tmpNode->getPosition()->x;
						dy = tmpNode->getNext()->getPosition()->y - tmpNode->getPosition()->y;
						if (dy!=-dx) mightBePassable = false;
					}
				}
				if (mightBePassable) {
					isPassable = true;
				}
			}
			if (isPassable) 
			{
				// anchor can directly see this node, make it next in the optimized path
				anchor->setNextOptimized( node );
				anchor = node;
				optimizedSegment = true;
				break;
			}
		}
			
		if (optimizedSegment == false)
		{
			// for some reason, there is no clear LOS between the anchor node and the very next node
			anchor->setNextOptimized( anchor->getNext() );
			anchor = anchor->getNext();
		}
	}

	// Remove jig/jogs :) jba.
	for (anchor=getFirstNode(); anchor!=NULL; anchor=anchor->getNextOptimized()) {
		node = anchor->getNextOptimized();
		if (node && node->getNextOptimized()) {
			Real dx = node->getPosition()->x - anchor->getPosition()->x;
			Real dy = node->getPosition()->y - anchor->getPosition()->y;
			// If the x & y offsets are less than 2 pathfind cells, kill it.
			if (dx*dx+dy*dy < sqr(PATHFIND_CELL_SIZE_F)*3.9f) {
				anchor->setNextOptimized(node->getNextOptimized());
			}
		}
	}

	// the path has been optimized
	m_isOptimized = true;
}

inline Bool isReallyClose(const Coord3D& a, const Coord3D& b)
{
	const Real CLOSE_ENOUGH = 0.1f;
	return 
		fabs(a.x-b.x) <= CLOSE_ENOUGH &&
		fabs(a.y-b.y) <= CLOSE_ENOUGH &&
		fabs(a.z-b.z) <= CLOSE_ENOUGH;
}

/**
 * Given a location, return the closest position on the path.
 * If 'allowBacktrack' is true, the entire path is considered.
 * If it is false, the point computed cannot be prior to previously returned non-backtracking points on this path.
 * Because the path "knows" the direction of travel, it will "lead" the given position a bit
 * to ensure the path is followed in the inteded direction.
 *
 * Note: The path cleanup does not take into account rolling terrain, so we can end up with
 * these situations:
 *
 *           B
 *        ######
 *      ##########
 *  A-##----------##---C
 * #######################
 *
 *
 * When an agent gets to B, he seems far off of the path, but it really not.
 * There are similar problems with valleys.
 *
 * Since agents track the closest path, if a high hill gets close to the underside of
 * a bridge, an agent may 'jump' to the higher path.  This must be avoided in maps.
 *
 * return along-path distance to the end will be returned as function result
 */
void Path::computePointOnPath(
	const Object* obj,
	const LocomotorSet& locomotorSet,
	const Coord3D& pos,
	ClosestPointOnPathInfo& out
)
{
	CRCDEBUG_LOG(("Path::computePointOnPath() fzor %s\n", DescribeObject(obj).str()));

	out.layer = LAYER_GROUND;
	out.posOnPath.zero();
	out.distAlongPath = 0;

	if (m_path == NULL)
	{
		m_cpopValid = false;
		return;
	}
	out.layer = m_path->getLayer();

	if (m_cpopValid && m_cpopCountdown>0 && isReallyClose(pos, m_cpopIn))
	{
		out = m_cpopOut;
		m_cpopCountdown--;
		CRCDEBUG_LOG(("Path::computePointOnPath() end because we're really close\n"));
		return;
	}
	m_cpopCountdown = MAX_CPOP;

	// default pathPos to end of the path
	out.posOnPath = *getLastNode()->getPosition();

	const PathNode* closeNode = NULL;
	Coord2D toPos;
	Real closeDistSqr = 99999999.9f;
	Real totalPathLength = 0.0f;
	Real lengthAlongPathToPos = 0.0f;

	//
	// Find the closest segment of the path
	//
#ifdef CPOP_STARTS_FROM_PREV_SEG
	const PathNode* prevNode = m_cpopRecentStart;
	if (prevNode == NULL)
		prevNode = m_path;
#else
	const PathNode* prevNode = m_path;
#endif
	Coord2D segmentDirNorm;
	Real segmentLength;

	// note that the seg dir and len returned by this is the dist & vec from 'prevNode' to 'node'
	for ( const PathNode* node = prevNode->getNextOptimized(&segmentDirNorm, &segmentLength); 
				node != NULL; 
				node = node->getNextOptimized(&segmentDirNorm, &segmentLength) )
	{
		const Coord3D* prevNodePos = prevNode->getPosition();
		const Coord3D* nodePos = node->getPosition();

		// compute vector from start of segment to pos
		toPos.x = pos.x - prevNodePos->x;
		toPos.y = pos.y - prevNodePos->y;

		// compute distance projection of 'toPos' onto segment
		Real alongPathDist = segmentDirNorm.x * toPos.x + segmentDirNorm.y * toPos.y;
				
		Coord3D pointOnPath;
		if (alongPathDist < 0.0f)
		{
			// projected point is before start of segment, use starting point
			alongPathDist = 0.0f;
			pointOnPath = *prevNodePos;
		}
		else if (alongPathDist > segmentLength)
		{
			// projected point is beyond end of segment, use end point
			if (node->getNextOptimized() == NULL)
			{
				alongPathDist = segmentLength;
				pointOnPath = *nodePos;
			}
			else
			{
				// beyond the end of this segment, skip this segment
				// if bend is sharp, start of next segment will grab this point
				// if bend is gradual, the point will project into the next segment
				totalPathLength += segmentLength;
				prevNode = node;
				continue;
			}
		}
		else
		{
			// projected point is on this segment, compute it
			pointOnPath.x = prevNodePos->x + alongPathDist * segmentDirNorm.x;
			pointOnPath.y = prevNodePos->y + alongPathDist * segmentDirNorm.y;
			pointOnPath.z = 0;
		}

		// compute distance to point on path, and track the closest we've found so far
		Coord2D offset;
		offset.x = pos.x - pointOnPath.x;
		offset.y = pos.y - pointOnPath.y;

		Real offsetDistSqr = offset.x*offset.x + offset.y*offset.y;
		if (offsetDistSqr < closeDistSqr)
		{
			closeDistSqr = offsetDistSqr;
			closeNode = prevNode;
			out.posOnPath = pointOnPath;

			lengthAlongPathToPos = totalPathLength + alongPathDist;
		}

		// add this segment's length to find total path length
		/// @todo Precompute this and store in path
		totalPathLength += segmentLength;
		prevNode = node;
		DUMPCOORD3D(&pointOnPath);
	}

#ifdef CPOP_STARTS_FROM_PREV_SEG
	m_cpopRecentStart = closeNode;
#endif

	//
	// Compute the goal movement position for this agent
	//
	if (closeNode && closeNode->getNextOptimized())
	{
		// note that the seg dir and len returned by this is the dist & vec from 'closeNode' to 'closeNext'
		const PathNode* closeNext = closeNode->getNextOptimized(&segmentDirNorm, &segmentLength);
		const Coord3D* nextNodePos = closeNext->getPosition();
		const Coord3D* closeNodePos = closeNode->getPosition();
		
		const PathNode* closePrev = closeNode->getPrevious();
		if (closePrev && closePrev->getLayer() > LAYER_GROUND) 
		{
			out.layer = closeNode->getLayer();
		}
		if (closeNode->getLayer() > LAYER_GROUND) 
		{
			out.layer = closeNode->getLayer();
		}

		if (closeNext->getLayer() > LAYER_GROUND) 
		{
			out.layer = closeNext->getLayer();
		}

		// compute vector from start of segment to pos
		toPos.x = pos.x - closeNodePos->x;
		toPos.y = pos.y - closeNodePos->y;

		// compute distance projection of 'toPos' onto segment
		Real alongPathDist = segmentDirNorm.x * toPos.x + segmentDirNorm.y * toPos.y;

		// we know this is the closest segment, so don't allow farther back than the start node
		if (alongPathDist < 0.0f)
			alongPathDist = 0.0f;

		// compute distance of point from this path segment
		Real toDistSqr = sqr(toPos.x) + sqr(toPos.y);
		Real offsetDistSq = toDistSqr - sqr(alongPathDist);
		Real offsetDist = (offsetDistSq <= 0.0) ? 0.0 : sqrt(offsetDistSq);

		// If we are basically on the path, return the next path node as the movement goal.
		// However, the farther off the path we get, the movement goal becomes closer to our
		// projected position on the path.  If we are very far off the path, we will move 
		// directly towards the nearest point on the path, and not the next path node.
		const Real maxPathError = 3.0f * PATHFIND_CELL_SIZE_F;
		const Real maxPathErrorInv = 1.0 / maxPathError;
		Real k = offsetDist * maxPathErrorInv;
		if (k > 1.0f)
			k = 1.0f;

		Bool gotPos = false;
		CRCDEBUG_LOG(("Path::computePointOnPath() calling isLinePassable() 1\n"));
		if (TheAI->pathfinder()->isLinePassable( obj, locomotorSet.getValidSurfaces(), out.layer, pos, *nextNodePos, 
			false, true )) 
		{
			out.posOnPath = *nextNodePos;
			gotPos = true;

			Bool tryAhead = alongPathDist > segmentLength * 0.5;
			if (closeNext->getCanOptimize() == false) 
			{
				tryAhead = false; // don't go past no-opt nodes.
			}
			if (closeNode->getLayer() != closeNext->getLayer()) 
			{
				tryAhead = false; // don't go past layers.
			}
			if (obj->getLayer()!=LAYER_GROUND) {
				tryAhead = false;
			}
			Bool veryClose = false;
			if (segmentLength-alongPathDist<1.0f) {
				tryAhead = true;
				veryClose = true;
			}
			if (tryAhead) 
			{
				// try next segment middle.	
				const PathNode *next = closeNext->getNextOptimized();
				if (next) 
				{
					Coord3D tryPos;
					tryPos.x = (nextNodePos->x + next->getPosition()->x) * 0.5;
					tryPos.y = (nextNodePos->y + next->getPosition()->y) * 0.5;
					tryPos.z = nextNodePos->z;
					CRCDEBUG_LOG(("Path::computePointOnPath() calling isLinePassable() 2\n"));
					if (veryClose || TheAI->pathfinder()->isLinePassable( obj, locomotorSet.getValidSurfaces(), closeNext->getLayer(), pos, tryPos, false, true )) 
					{
						gotPos = true;
						out.posOnPath = tryPos;
					}
				}
			}
		} 
		else if (k > 0.5f) 
		{
			Real tryDist = alongPathDist + (0.5) * (segmentLength - alongPathDist);

			// projected point is on this segment, compute it
			out.posOnPath.x = closeNodePos->x + tryDist * segmentDirNorm.x;
			out.posOnPath.y = closeNodePos->y + tryDist * segmentDirNorm.y;
			out.posOnPath.z = closeNodePos->z;

			CRCDEBUG_LOG(("Path::computePointOnPath() calling isLinePassable() 3\n"));
			if (TheAI->pathfinder()->isLinePassable( obj, locomotorSet.getValidSurfaces(), out.layer, pos, out.posOnPath, false, true )) 
			{
				k = 0.5f;
				gotPos = true;
			}
		}	

		// if we are on the path (k == 0), then alongPathDist == segmentLength
		// if we are way off the path (k == 1), then alongPathDist is unchanged, and it projection of actual pos
		alongPathDist += (1.0f - k) * (segmentLength - alongPathDist);

		if (!gotPos) 
		{
			if (alongPathDist > segmentLength)
			{
				alongPathDist = segmentLength;
				out.posOnPath = *nextNodePos;
			}
			else
			{
				// projected point is on this segment, compute it
				out.posOnPath.x = closeNodePos->x + alongPathDist * segmentDirNorm.x;
				out.posOnPath.y = closeNodePos->y + alongPathDist * segmentDirNorm.y;
				out.posOnPath.z = closeNodePos->z;
				Real dx = fabs(pos.x - out.posOnPath.x);
				Real dy = fabs(pos.y - out.posOnPath.y);
				if (dx<1 && dy<1 && closeNode->getNextOptimized() && closeNode->getNextOptimized()->getNextOptimized()) {
					out.posOnPath = *closeNode->getNextOptimized()->getNextOptimized()->getPosition();
				}
			}
		}
	}

	TheAI->pathfinder()->setDebugPathPosition( &out.posOnPath );

	out.distAlongPath = totalPathLength - lengthAlongPathToPos;

	Coord3D delta;
	delta.x = out.posOnPath.x - pos.x;
	delta.y = out.posOnPath.y - pos.y;
	delta.z = 0;
	Real lenDelta = delta.length();
	if (lenDelta > out.distAlongPath && out.distAlongPath > PATHFIND_CLOSE_ENOUGH) 
	{
		out.distAlongPath = lenDelta;
	}

	m_cpopIn = pos;
	m_cpopOut = out;
	m_cpopValid = true;
	CRCDEBUG_LOG(("Path::computePointOnPath() end\n"));

}


/**
	Given a position, computes the distance to the goal.  Returns 0 if we are past the goal.
	Returns the goal position in goalPos.  This is intended for use with flying paths, that go
	directly to the goal and don't consider obstacles.  jba.
 */
Real Path::computeFlightDistToGoal( const Coord3D *pos, Coord3D& goalPos )
{
	if (m_path == NULL)
	{
		goalPos.x = 0.0f;
		goalPos.y = 0.0f;
		goalPos.z = 0.0f;
		return 0.0f;
	}
	const PathNode *curNode = getFirstNode();
	if (m_cpopRecentStart) {
		curNode = m_cpopRecentStart;
	} else {
		m_cpopRecentStart = curNode;
	}
	const PathNode *nextNode = curNode->getNextOptimized();
	goalPos = *curNode->getPosition();
	Real distance = 0;
	Bool useNext = true;
	while (nextNode) {

		if (useNext) {
			goalPos = *nextNode->getPosition();
		}

		Coord3D startPos = *curNode->getPosition();
		Coord3D endPos = *nextNode->getPosition();

		Coord2D posToGoalVector;
		// posToGoalVector is pos to goalPos vector.
		posToGoalVector.x = endPos.x - pos->x;
		posToGoalVector.y = endPos.y - pos->y;

		// pathVector is the startPos to goal pos vector.
		Coord2D pathVector;
		pathVector.x = endPos.x - startPos.x;
		pathVector.y = endPos.y - startPos.y;

		// Normalize pathVector
		pathVector.normalize();

		// Dot product is the posToGoal vector projected onto the path vector.
		Real dotProduct = posToGoalVector.x*pathVector.x	+ posToGoalVector.y*pathVector.y;
		if (dotProduct>=0) {
			distance += dotProduct;
			useNext = false;
		}	else if (useNext) {
			m_cpopRecentStart = nextNode;
		}
		curNode = nextNode;
		nextNode = curNode->getNextOptimized();
	}
	return distance;

}
//-----------------------------------------------------------------------------------

enum { PATHFIND_CELLS_PER_FRAME=5000}; // Number of cells we will search pathfinding per frame.
enum {CELL_INFOS_TO_ALLOCATE = 30000};
PathfindCellInfo *PathfindCellInfo::s_infoArray = NULL;
PathfindCellInfo *PathfindCellInfo::s_firstFree = NULL;						
/**
 * Allocates a pool of pathfind cell infos.
 */
void PathfindCellInfo::allocateCellInfos(void) 
{
	releaseCellInfos();
	s_infoArray = MSGNEW("PathfindCellInfo") PathfindCellInfo[CELL_INFOS_TO_ALLOCATE];	// pool[]ify
	s_infoArray[CELL_INFOS_TO_ALLOCATE-1].m_pathParent = NULL;
	s_infoArray[CELL_INFOS_TO_ALLOCATE-1].m_isFree = true;
	s_firstFree = s_infoArray;
	for (Int i=0; i<CELL_INFOS_TO_ALLOCATE-1; i++) {
		s_infoArray[i].m_pathParent = &s_infoArray[i+1];
		s_infoArray[i].m_isFree = true; 
	}
}

/**
 * Releases a pool of pathfind cell infos.
 */
void PathfindCellInfo::releaseCellInfos(void) 
{
	if (s_infoArray==NULL) {
		return; // haven't allocated any yet.
	}
	Int count=0;
	while (s_firstFree) {
		count++;
		DEBUG_ASSERTCRASH(s_firstFree->m_isFree, ("Should be freed."));
		s_firstFree = s_firstFree->m_pathParent;
	}
	DEBUG_ASSERTCRASH(count==CELL_INFOS_TO_ALLOCATE, ("Error - Allocated cellinfos."));
	delete s_infoArray;
	s_infoArray = NULL;
	s_firstFree = NULL;
}

/**
 * Gets a pathfindcellinfo.
 */
PathfindCellInfo *PathfindCellInfo::getACellInfo(PathfindCell *cell,const ICoord2D &pos) 
{
	PathfindCellInfo *info = s_firstFree;
	if (s_firstFree) {
		DEBUG_ASSERTCRASH(s_firstFree->m_isFree, ("Should be freed."));
		s_firstFree = s_firstFree->m_pathParent;
		info->m_isFree = false;  // Just allocated it.
		info->m_cell = cell;
		info->m_pos = pos;

		info->m_nextOpen = NULL;
		info->m_prevOpen = NULL;
		info->m_pathParent = NULL;
		info->m_costSoFar = 0;		
		info->m_totalCost = 0;
		info->m_open = 0;
		info->m_closed = 0;
		info->m_obstacleID = INVALID_ID;
		info->m_goalUnitID = INVALID_ID;
		info->m_posUnitID = INVALID_ID;
		info->m_goalAircraftID = INVALID_ID;
		info->m_obstacleIsFence = false;
		info->m_obstacleIsTransparent = false;
		info->m_blockedByAlly = false;
	}
	return info;
}

/**
 * Returns a pathfindcellinfo.
 */
void PathfindCellInfo::releaseACellInfo(PathfindCellInfo *theInfo) 
{
	DEBUG_ASSERTCRASH(!theInfo->m_isFree, ("Shouldn't be free."));
	//@ todo -fix this assert on usa04.  jba.
	//DEBUG_ASSERTCRASH(theInfo->m_obstacleID==0, ("Shouldn't be obstacle."));
	theInfo->m_pathParent = s_firstFree;
	s_firstFree = theInfo;
	s_firstFree->m_isFree = true;
}

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

/**
 * Constructor
 */
PathfindCell::PathfindCell( void ) :m_info(NULL)
{ 
	reset();
}

/**
 * Destructor
 */
PathfindCell::~PathfindCell( void ) 
{ 	
	if (m_info) PathfindCellInfo::releaseACellInfo(m_info);
	m_info = NULL;
	static warn = true;
	if (warn) {
		warn = false;
		DEBUG_LOG( ("PathfindCell::~PathfindCell m_info Allocated."));
	}
}

/**
 * Reset the cell to default values
 */
void PathfindCell::reset( ) 
{ 
	m_type = PathfindCell::CELL_CLEAR; 
	m_flags = PathfindCell::NO_UNITS;
	m_zone = 0;
	m_aircraftGoal = false;
	m_pinched = false;
	if (m_info) {
		m_info->m_obstacleID = INVALID_ID;
		PathfindCellInfo::releaseACellInfo(m_info);
		m_info = NULL;
	}
	m_connectsToLayer = LAYER_INVALID;
	m_layer = LAYER_GROUND;
	
}

/**
 * Reset the pathfinding values in the cell.
 */
Bool PathfindCell::startPathfind( PathfindCell *goalCell  ) 
{ 
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	m_info->m_nextOpen = NULL;
	m_info->m_prevOpen = NULL;
	m_info->m_pathParent = NULL;
	m_info->m_costSoFar = 0;		// start node, no cost to get here
	m_info->m_totalCost = 0;
	if (goalCell) {
		m_info->m_totalCost = costToGoal( goalCell );
	}
	m_info->m_open = TRUE;
	m_info->m_closed = FALSE;
	return true;
}
/**
 * Set the parent pointer.
 */
void PathfindCell::setParentCell( PathfindCell* parent  ) 
{ 
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	m_info->m_pathParent = parent->m_info;
	Int dx = m_info->m_pos.x - parent->m_info->m_pos.x;
	Int dy = m_info->m_pos.y - parent->m_info->m_pos.y;
	if (dx<-1 || dx>1 || dy<-1 || dy>1) {
		DEBUG_CRASH(("Invalid parent index."));
	}
}

/**
 * Set the parent pointer.
 */
void PathfindCell::setParentCellHierarchical( PathfindCell* parent  ) 
{ 
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	m_info->m_pathParent = parent->m_info;
}

/**
 * Reset the parent cell.
 */
void PathfindCell::clearParentCell( void  ) 
{ 
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	m_info->m_pathParent = NULL;
}


/**
 * Allocates an info record for a cell.
 */
Bool PathfindCell::allocateInfo( const ICoord2D &pos ) 
{ 
	if (!m_info) {
		m_info = PathfindCellInfo::getACellInfo(this, pos);
		return (m_info != NULL);
	} 
	return true;
}

/**
 * Releases an info record for a cell.
 */
void PathfindCell::releaseInfo( void ) 
{ 
	if (m_type==PathfindCell::CELL_OBSTACLE) {
		return;
	}
	if (m_flags!=NO_UNITS) {
		return;
	}
	if (m_aircraftGoal) {
		return;
	}

	if (m_info) {
		DEBUG_ASSERTCRASH(m_info->m_prevOpen==NULL && m_info->m_nextOpen==NULL, ("Shouldn't be linked."));
		DEBUG_ASSERTCRASH(m_info->m_open==NULL && m_info->m_closed==NULL, ("Shouldn't be linked."));
		DEBUG_ASSERTCRASH(m_info->m_goalUnitID==INVALID_ID && m_info->m_posUnitID==INVALID_ID, ("Shouldn't be occupied."));
		DEBUG_ASSERTCRASH(m_info->m_goalAircraftID==INVALID_ID , ("Shouldn't be occupied by aircraft."));
		if (m_info->m_prevOpen || m_info->m_nextOpen || m_info->m_open || m_info->m_closed) {
			// Bad release.  Skip for now, better leak than crash.  jba.
			return;
		}
		PathfindCellInfo::releaseACellInfo(m_info);
		m_info = NULL;
	}
}

/**
 * Sets the goal unit into the info record for a cell.
 */
void PathfindCell::setGoalUnit(ObjectID unitID, const ICoord2D &pos ) 
{ 
	if (unitID==INVALID_ID) {
		// removing goal.
		if (m_info) {
			m_info->m_goalUnitID = INVALID_ID;
			if (m_info->m_posUnitID == INVALID_ID) {
				// No units here.
				DEBUG_ASSERTCRASH(m_flags==UNIT_GOAL, ("Bad flags."));
				m_flags = NO_UNITS;
				releaseInfo();
			} else{
				m_flags = UNIT_PRESENT_MOVING;
			}
		}	else {
			DEBUG_ASSERTCRASH(m_flags == NO_UNITS, ("Bad flags."));
		}
	} else {
		// adding goal.
		if (!m_info) {
			DEBUG_ASSERTCRASH(m_flags == NO_UNITS, ("Bad flags."));
			allocateInfo(pos);
		}
		if (!m_info) {
			DEBUG_CRASH(("Ran out of pathfind cells - fatal error!!!!! jba. "));
			return;
		}
		m_info->m_goalUnitID = unitID;
		if (unitID==m_info->m_posUnitID) {
			m_flags = UNIT_PRESENT_FIXED;
		} else if (m_info->m_posUnitID==INVALID_ID) {
			m_flags = UNIT_GOAL;
		}	else {
			m_flags = UNIT_GOAL_OTHER_MOVING;
		}
	}
}


/**
 * Sets the goal aircraft into the info record for a cell.
 */
void PathfindCell::setGoalAircraft(ObjectID unitID, const ICoord2D &pos ) 
{ 
	if (unitID==INVALID_ID) {
		// removing goal.
		if (m_info) {
			m_info->m_goalAircraftID = INVALID_ID;
			m_aircraftGoal = false;
			releaseInfo();
		}	else {
			DEBUG_ASSERTCRASH(m_aircraftGoal==false, ("Bad flags."));
		}
	} else {
		// adding goal.
		if (!m_info) {
			DEBUG_ASSERTCRASH(m_aircraftGoal==false, ("Bad flags."));
			allocateInfo(pos);
		}
		if (!m_info) {
			DEBUG_CRASH(("Ran out of pathfind cells - fatal error!!!!! jba. "));
			return;
		}
		m_info->m_goalAircraftID = unitID;
		m_aircraftGoal = true;
	}
}


/**
 * Sets the position unit into the info record for a cell.
 */
void PathfindCell::setPosUnit(ObjectID unitID, const ICoord2D &pos ) 
{ 
	if (unitID==INVALID_ID) {
		// removing position.
		if (m_info) {
			m_info->m_posUnitID = INVALID_ID;
			if (m_info->m_goalUnitID == INVALID_ID) {
				// No units here.
				DEBUG_ASSERTCRASH(m_flags==UNIT_PRESENT_MOVING, ("Bad flags."));
				m_flags = NO_UNITS;
				releaseInfo();
			}	else {
				m_flags = UNIT_GOAL;
			}
		}	else {
			DEBUG_ASSERTCRASH(m_flags == NO_UNITS, ("Bad flags."));
		}
	} else {
		// adding goal.
		if (!m_info) {
			DEBUG_ASSERTCRASH(m_flags == NO_UNITS, ("Bad flags."));
			allocateInfo(pos);
		}
		if (!m_info) {
			DEBUG_CRASH(("Ran out of pathfind cells - fatal error!!!!! jba. "));
			return;
		}
		if (m_info->m_goalUnitID!=INVALID_ID && (m_info->m_goalUnitID==m_info->m_posUnitID)) {
			// A unit is already occupying this cell.
			return;
		}
		m_info->m_posUnitID = unitID;
		if (unitID==m_info->m_goalUnitID) {
			m_flags = UNIT_PRESENT_FIXED;
		} else if (m_info->m_goalUnitID==INVALID_ID) {
			m_flags = UNIT_PRESENT_MOVING;
		}	else {
			m_flags = UNIT_GOAL_OTHER_MOVING;
		}
	}
}


/**
 * Flag this cell as an obstacle, from the given one
 */
void PathfindCell::setTypeAsObstacle( Object *obstacle, Bool isFence, const ICoord2D &pos )
{
	if (m_type!=PathfindCell::CELL_CLEAR && m_type != PathfindCell::CELL_IMPASSABLE) {
		return;
	}

	Bool isRubble = false;
	if (obstacle->getBodyModule() && obstacle->getBodyModule()->getDamageState() == BODY_RUBBLE) 
	{
		isRubble = true;
	}

	if (isRubble) {
		m_type = PathfindCell::CELL_RUBBLE;
		if (m_info) {
			m_info->m_obstacleID = INVALID_ID;
			releaseInfo();
		}
		return;
	}

	m_type = PathfindCell::CELL_OBSTACLE ;
	if (!m_info) {
		m_info = PathfindCellInfo::getACellInfo(this, pos);
		if (!m_info) {
			DEBUG_CRASH(("Not enough PathFindCellInfos in pool."));
			return;
		}
	}
	m_info->m_obstacleID = obstacle->getID();
	m_info->m_obstacleIsFence = isFence;
	m_info->m_obstacleIsTransparent = obstacle->isKindOf(KINDOF_CAN_SEE_THROUGH_STRUCTURE);
}

/**
 * Flag this cell as given type.
 */
void PathfindCell::setType( CellType type )
{
	if (m_info && (m_info->m_obstacleID != INVALID_ID)) {
		DEBUG_ASSERTCRASH(type==PathfindCell::CELL_OBSTACLE, ("Wrong type."));
		m_type = PathfindCell::CELL_OBSTACLE;
		return;
	}
	m_type = type;
}

/**
 * Flag this cell as an obstacle, from the given one
 */
void PathfindCell::removeObstacle( Object *obstacle )
{
	if (m_type == PathfindCell::CELL_RUBBLE) {
		m_type = PathfindCell::CELL_CLEAR;
	}
	if (!m_info) return;
	if (m_info->m_obstacleID != obstacle->getID()) return;
	m_type = PathfindCell::CELL_CLEAR;
	if (m_info) {
		m_info->m_obstacleID = INVALID_ID;
		releaseInfo();
	}
}

/// put self on "open" list in ascending cost order, return new list
PathfindCell *PathfindCell::putOnSortedOpenList( PathfindCell *list )
{
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	DEBUG_ASSERTCRASH(m_info->m_closed==FALSE && m_info->m_open==FALSE, ("Serious error - Invalid flags. jba"));
	if (list == NULL)
	{
		list = this;
		m_info->m_prevOpen = NULL;
		m_info->m_nextOpen = NULL;
	}
	else
	{
		// insertion sort
		PathfindCell *c, *lastCell = NULL;
		for( c = list; c; c = c->getNextOpen() )
		{
			if (c->m_info->m_totalCost > m_info->m_totalCost)
				break;

			lastCell = c;
		}

		if (c)
		{
			// insert just before "c"
			if (c->m_info->m_prevOpen)
				c->m_info->m_prevOpen->m_nextOpen = this->m_info;
			else
				list = this;

			m_info->m_prevOpen = c->m_info->m_prevOpen;
			c->m_info->m_prevOpen = this->m_info;
				
			m_info->m_nextOpen = c->m_info;

		}
		else
		{
			// append after "lastCell" - end of list
			lastCell->m_info->m_nextOpen = this->m_info;
			m_info->m_prevOpen = lastCell->m_info;
			m_info->m_nextOpen = NULL;
		}
	}

	// mark newCell as being on open list
	m_info->m_open = true;
	m_info->m_closed = false;

	return list;
}

/// remove self from "open" list
PathfindCell *PathfindCell::removeFromOpenList( PathfindCell *list )
{
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	DEBUG_ASSERTCRASH(m_info->m_closed==FALSE && m_info->m_open==TRUE, ("Serious error - Invalid flags. jba"));
	if (m_info->m_nextOpen)
		m_info->m_nextOpen->m_prevOpen = m_info->m_prevOpen;
	
	if (m_info->m_prevOpen)
		m_info->m_prevOpen->m_nextOpen = m_info->m_nextOpen;
	else
		list = getNextOpen();

	m_info->m_open = false;
	m_info->m_nextOpen = NULL;
	m_info->m_prevOpen = NULL;

	return list;
}

/// remove all cells from "open" list
Int PathfindCell::releaseOpenList( PathfindCell *list )
{
	Int count = 0;
	while (list) {
		count++;
		DEBUG_ASSERTCRASH(list->m_info, ("Has to have info."));
		DEBUG_ASSERTCRASH(list->m_info->m_closed==FALSE && list->m_info->m_open==TRUE, ("Serious error - Invalid flags. jba"));
		PathfindCell *cur = list;
		PathfindCellInfo *curInfo = list->m_info;
		if (curInfo->m_nextOpen) {
			list = curInfo->m_nextOpen->m_cell;
		}	else {
			list = NULL;
		}
		DEBUG_ASSERTCRASH(cur == curInfo->m_cell, ("Bad backpointer in PathfindCellInfo"));
		curInfo->m_nextOpen = NULL;
		curInfo->m_prevOpen = NULL;
		curInfo->m_open = FALSE;
		cur->releaseInfo();
	}
	return count;
}

/// remove all cells from "closed" list
Int PathfindCell::releaseClosedList( PathfindCell *list )
{
	Int count = 0;
	while (list) {
		count++;
		DEBUG_ASSERTCRASH(list->m_info, ("Has to have info."));
		DEBUG_ASSERTCRASH(list->m_info->m_closed==TRUE && list->m_info->m_open==FALSE, ("Serious error - Invalid flags. jba"));
		PathfindCell *cur = list;
		PathfindCellInfo *curInfo = list->m_info;
		if (curInfo->m_nextOpen) {
			list = curInfo->m_nextOpen->m_cell;
		}	else {
			list = NULL;
		}
		DEBUG_ASSERTCRASH(cur == curInfo->m_cell, ("Bad backpointer in PathfindCellInfo"));
		curInfo->m_nextOpen = NULL;
		curInfo->m_prevOpen = NULL;
		curInfo->m_closed = FALSE;
		cur->releaseInfo();
	}
	return count;
}

/// put self on "closed" list, return new list
PathfindCell *PathfindCell::putOnClosedList( PathfindCell *list )
{
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	DEBUG_ASSERTCRASH(m_info->m_closed==FALSE && m_info->m_open==FALSE, ("Serious error - Invalid flags. jba"));
	// only put on list if not already on it
	if (m_info->m_closed == FALSE)
	{
		m_info->m_closed = FALSE;
		m_info->m_closed = TRUE;

		m_info->m_prevOpen = NULL;
		m_info->m_nextOpen = list?list->m_info:NULL;
		if (list)
			list->m_info->m_prevOpen = this->m_info;
		
		list = this;
	}

	return list;
}

/// remove self from "closed" list
PathfindCell *PathfindCell::removeFromClosedList( PathfindCell *list )
{
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	DEBUG_ASSERTCRASH(m_info->m_closed==TRUE && m_info->m_open==FALSE, ("Serious error - Invalid flags. jba"));
	if (m_info->m_nextOpen)
		m_info->m_nextOpen->m_prevOpen = m_info->m_prevOpen;
	
	if (m_info->m_prevOpen)
		m_info->m_prevOpen->m_nextOpen = m_info->m_nextOpen;
	else
		list = getNextOpen();

	m_info->m_closed = false;
	m_info->m_nextOpen = NULL;
	m_info->m_prevOpen = NULL;

	return list;
}

const Int COST_ORTHOGONAL = 10;
const Int COST_DIAGONAL = 14;
const Real COST_TO_DISTANCE_FACTOR = 1.0f/10.0f;
const Real COST_TO_DISTANCE_FACTOR_SQR = COST_TO_DISTANCE_FACTOR*COST_TO_DISTANCE_FACTOR;

UnsignedInt PathfindCell::costToGoal( PathfindCell *goal )
{
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	Int dx = m_info->m_pos.x - goal->getXIndex();
	Int dy = m_info->m_pos.y - goal->getYIndex();
#define NO_REAL_DIST
#ifdef REAL_DIST
	Int cost = COST_ORTHOGONAL*sqrt(dx*dx + dy*dy);
#else
	if (dx<0) dx = -dx;
	if (dy<0) dy = -dy;
	Int cost;
	if (dx>dy) {
		cost= COST_ORTHOGONAL*dx + (COST_ORTHOGONAL*dy)/2;
	}	else {
		cost= COST_ORTHOGONAL*dy + (COST_ORTHOGONAL*dx)/2;
	}

#endif


	return cost;
}

UnsignedInt PathfindCell::costToHierGoal( PathfindCell *goal )
{
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	Int dx = m_info->m_pos.x - goal->getXIndex();
	Int dy = m_info->m_pos.y - goal->getYIndex();
	Int cost = REAL_TO_INT_FLOOR(COST_ORTHOGONAL*sqrt(dx*dx + dy*dy) + 0.5f);
	return cost;
}

UnsignedInt PathfindCell::costSoFar( PathfindCell *parent )
{
	DEBUG_ASSERTCRASH(m_info, ("Has to have info."));
	// very first node in path - no turns, no cost
	if (parent == NULL)
		return 0;

	// add in number of turns in path so far
	ICoord2D prevDir;
	Int cost;

	prevDir.x = parent->getXIndex() - m_info->m_pos.x;
	prevDir.y = parent->getYIndex() - m_info->m_pos.y;

	// diagonal moves cost a bit more than orthogonal ones
	if (prevDir.x == 0 || prevDir.y == 0)
		cost = parent->getCostSoFar() + COST_ORTHOGONAL;
	else
		cost = parent->getCostSoFar() + COST_DIAGONAL;
	if (getPinched()) {
		cost += 1*COST_DIAGONAL;
	}

#if 1
	// Increase cost of turns.
	Int numTurns = 0;
	PathfindCell *prevCell = parent->getParentCell();
	if (prevCell) {
		ICoord2D dir;
		dir.x = prevCell->getXIndex() - parent->getXIndex();
		dir.y = prevCell->getYIndex() - parent->getYIndex();
		
		// count number of direction changes
		if (dir.x != prevDir.x || dir.y != prevDir.y)
		{
			Int dot = dir.x * prevDir.x + dir.y * prevDir.y;
			if (dot > 0)
				numTurns=4;				// 45 degree turn
			else if (dot == 0)
				numTurns = 8;		// 90 degree turn
			else
				numTurns = 16;		// 135 degree turn
		}
	}

	return cost + numTurns;
#else
	return cost;
#endif

}


inline Bool typesMatch(const PathfindCell &targetCell, const PathfindCell &sourceCell) {
	PathfindCell::CellType targetType = targetCell.getType();
	PathfindCell::CellType srcType = sourceCell.getType();
	if (targetType == srcType) return true;
	
	return false;
}

inline Bool waterGround(const PathfindCell &targetCell, const PathfindCell &sourceCell) {
	PathfindCell::CellType targetType = targetCell.getType();
	PathfindCell::CellType srcType = sourceCell.getType();
	if ( (targetType==PathfindCell::CELL_CLEAR && 
		(srcType&PathfindCell::CELL_WATER ))) {
			return true;
	}
	if ( (srcType==PathfindCell::CELL_CLEAR && 
		(targetType&PathfindCell::CELL_WATER ))) {
			return true;
	}

	return false;
}

inline Bool groundRubble(const PathfindCell &targetCell, const PathfindCell &sourceCell) {
	PathfindCell::CellType targetType = targetCell.getType();
	PathfindCell::CellType srcType = sourceCell.getType();
	if ( (targetType==PathfindCell::CELL_CLEAR && 
		(srcType==PathfindCell::CELL_RUBBLE ))) {
			return true;
	}
	if ( (srcType==PathfindCell::CELL_CLEAR && 
		(targetType==PathfindCell::CELL_RUBBLE ))) {
			return true;
	}

	return false;
}

inline Bool terrain(const PathfindCell &targetCell, const PathfindCell &sourceCell) {
	Int targetType = targetCell.getType();
	Int srcType = sourceCell.getType();
	if (targetType == PathfindCell::CELL_OBSTACLE) targetType = PathfindCell::CELL_CLEAR;
	if (srcType == PathfindCell::CELL_OBSTACLE) srcType = PathfindCell::CELL_CLEAR;
	if (targetType==srcType) {
		return true;
	}
	return false;
}

inline Bool crusherGround(const PathfindCell &targetCell, const PathfindCell &sourceCell) {
	Int targetType = targetCell.getType();
	Int srcType = sourceCell.getType();
	if (targetType==PathfindCell::CELL_OBSTACLE) {
		if (targetCell.isObstacleFence()) {
			if (srcType == PathfindCell::CELL_CLEAR) {
				return true;
			}
		}
	}
	if (srcType==PathfindCell::CELL_OBSTACLE) {
		if (sourceCell.isObstacleFence()) {
			if (targetType == PathfindCell::CELL_CLEAR) {
				return true;
			}
		}
	}
	return false;
}

inline Bool groundCliff(const PathfindCell &targetCell, const PathfindCell &sourceCell) {
	PathfindCell::CellType targetType = targetCell.getType();
	PathfindCell::CellType srcType = sourceCell.getType();
	
	if ( (targetType==PathfindCell::CELL_CLIFF ) && 
			 (srcType==PathfindCell::CELL_CLEAR) ) {
			return true;
	}
	if ( (targetType==PathfindCell::CELL_CLEAR ) && 
			 (srcType==PathfindCell::CELL_CLIFF) ) {
			return true;
	}
	return false;
}

static void __fastcall resolveBlockZones(Int srcZone, Int targetZone, UnsignedShort *zoneEquivalency, Int sizeOfZE)
{
	Int i;
	// We have two zones being combined now. Keep the lower zone.
	DEBUG_ASSERTCRASH(srcZone!=0 && targetZone!=0,  ("Bad resolve zones	."));
	if (targetZone<srcZone) {
		for (i=0; i<sizeOfZE; i++) {
			if (zoneEquivalency[i] == srcZone) {
				zoneEquivalency[i] = targetZone;
			}
		}
	} else {
		for (i=0; i<sizeOfZE; i++) {
			if (zoneEquivalency[i] == targetZone) {
				zoneEquivalency[i] = srcZone;
			}
		}
	}
}

static void __fastcall resolveZones(Int srcZone, Int targetZone, UnsignedShort *zoneEquivalency, Int sizeOfZE)
{
	Int i;
	// We have two zones being combined now. Keep the lower zone.
	DEBUG_ASSERTCRASH(srcZone!=0 && targetZone!=0,  ("Bad resolve zones	."));
	DEBUG_ASSERTCRASH(srcZone<sizeOfZE && targetZone<sizeOfZE,  ("Bad resolve zones	."));
	srcZone = zoneEquivalency[srcZone];
	targetZone = zoneEquivalency[targetZone];
	DEBUG_ASSERTCRASH(srcZone<sizeOfZE && targetZone<sizeOfZE,  ("Bad resolve zones	."));
	UnsignedShort finalZone;
	if (targetZone<srcZone) {
		finalZone = zoneEquivalency[targetZone];
	} else {
		finalZone = zoneEquivalency[srcZone];
	}
	DEBUG_ASSERTCRASH(finalZone<sizeOfZE ,  ("Bad resolve zones	."));
	for (i=0; i<sizeOfZE; i++) { 
		UnsignedShort ze = zoneEquivalency[i];
		if (ze == targetZone || ze == srcZone) {
			zoneEquivalency[i] = finalZone;
		}
	}
}

static void flattenZones(UnsignedShort *zoneArray, UnsignedShort *zoneHierarchical, Int sizeOfZones)
{
	Int i;
	for (i=0; i<sizeOfZones; i++) {
		Int zone1 = zoneArray[i];
		Int zone2 = zoneHierarchical[zone1];
		zone1 = zoneArray[zone2];
		zone2 = zoneHierarchical[zone1];
		zoneArray[i] = zone2;
	}
#if 1

	for (i=0; i<sizeOfZones; i++) {
		Int zone1 = zoneArray[i];
		Int zone2 = zoneHierarchical[i];
		if (zone1!=zone2) {
			resolveZones(zone1, zone2, zoneArray, sizeOfZones);
		}
	}
#endif
}

inline void applyZone(PathfindCell &targetCell, const PathfindCell &sourceCell, UnsignedShort *zoneEquivalency, Int sizeOfZE)
{
	DEBUG_ASSERTCRASH(sourceCell.getZone()!=0, ("Unset source zone."));
	Int srcZone = zoneEquivalency[sourceCell.getZone()];
	//DEBUG_ASSERTCRASH(srcZone!=0, ("Bad zone equivalency zone."));
	Int targetZone = zoneEquivalency[targetCell.getZone()];

	if (targetZone == 0) {
		targetCell.setZone(srcZone);
		return;
	}
	if (targetZone == srcZone) {
		return; // already match.
	}
	resolveZones(srcZone, targetZone, zoneEquivalency, sizeOfZE);

}

inline void applyBlockZone(PathfindCell &targetCell, const PathfindCell &sourceCell,
													 UnsignedShort *zoneEquivalency, Int firstZone, Int sizeOfZE)
{	
	DEBUG_ASSERTCRASH(sourceCell.getZone()>=firstZone && sourceCell.getZone()<firstZone+sizeOfZE, ("Memory overrun - FATAL ERROR."));
	Int srcZone = zoneEquivalency[sourceCell.getZone()-firstZone];
	DEBUG_ASSERTCRASH(targetCell.getZone()>=firstZone && sourceCell.getZone()<firstZone+sizeOfZE, ("Memory overrun - FATAL ERROR."));
	Int targetZone = zoneEquivalency[targetCell.getZone()-firstZone];
	if (targetZone == srcZone) {
		return; // already match.
	}
	resolveBlockZones(srcZone, targetZone, zoneEquivalency, sizeOfZE);

}

//------------------------  ZoneBlock  -------------------------------
ZoneBlock::ZoneBlock() : m_firstZone(0), 
m_numZones(0), 
m_groundCliffZones(NULL), 
m_groundWaterZones(NULL), 
m_groundRubbleZones(NULL), 
m_crusherZones(NULL), 
m_zonesAllocated(0),
m_interactsWithBridge(FALSE)
{		
	m_cellOrigin.x = 0;
	m_cellOrigin.y = 0;
	//Added By Sadullah Nader
	//Initialization(s) inserted
	m_firstZone = 0;
	m_markedPassable = TRUE;
	//
}

ZoneBlock::~ZoneBlock()  
{
	freeZones();
}

void ZoneBlock::freeZones(void) 
{
	if (m_groundCliffZones) {
		delete [] m_groundCliffZones;
		m_groundCliffZones = NULL;
	}
	if (m_groundWaterZones) {
		delete [] m_groundWaterZones;
		m_groundWaterZones = NULL;
	}
	if (m_groundRubbleZones) {
		delete [] m_groundRubbleZones;
		m_groundRubbleZones = NULL;
	}
	if (m_crusherZones) {
		delete [] m_crusherZones;
		m_crusherZones = NULL;
	}
}

/* Allocate zone equivalency arrays large enough to hold required entries.  If the arrays are already
large enough, reuse.  Then calculate terrain equivalencies. */
void ZoneBlock::blockCalculateZones(PathfindCell **map, PathfindLayer layers[], const IRegion2D &bounds) 
{
	Int i, j;
	m_cellOrigin = bounds.lo;
	UnsignedInt minZone = map[bounds.lo.x][bounds.lo.y].getZone();
	UnsignedInt maxZone = minZone;

	for( j=bounds.lo.y; j<=bounds.hi.y; j++ )	{
		for( i=bounds.lo.x; i<=bounds.hi.x; i++ )	{
			PathfindCell *cell = &map[i][j];
			UnsignedShort zone = cell->getZone();
			if (minZone>zone) minZone=zone;
			if (maxZone<zone) maxZone=zone;
		}
	}
	m_firstZone = minZone;
	m_numZones = 1 + maxZone - minZone;

	allocateZones();

	if (m_numZones==1) return; // all zones are equivalent.

	// Determine water/ground equivalent zones, and ground/cliff equivalent zones.
	for (i=0; i<m_zonesAllocated; i++) {
		m_groundCliffZones[i] = i+m_firstZone;
		m_groundWaterZones[i] = i+m_firstZone;
		m_groundRubbleZones[i] = i+m_firstZone;
		m_crusherZones[i] = i+m_firstZone;
	}

	for( j=bounds.lo.y; j<=bounds.hi.y; j++ )	{
		for( i=bounds.lo.x; i<=bounds.hi.x; i++ )	{
			if (i>bounds.lo.x && map[i][j].getZone()!=map[i-1][j].getZone()) {

				if (waterGround(map[i][j], map[i-1][j])) {
					applyBlockZone(map[i][j], map[i-1][j], m_groundWaterZones, m_firstZone, m_numZones);
				}
				if (groundRubble(map[i][j], map[i-1][j])) {
					applyBlockZone(map[i][j], map[i-1][j], m_groundRubbleZones, m_firstZone, m_numZones);
				}
				if (groundCliff(map[i][j], map[i-1][j])) {
					applyBlockZone(map[i][j], map[i-1][j], m_groundCliffZones, m_firstZone, m_numZones);
				}
				if (crusherGround(map[i][j], map[i-1][j])) {
					applyBlockZone(map[i][j], map[i-1][j], m_crusherZones, m_firstZone, m_numZones);
				}
			}
			if (j>bounds.lo.y && map[i][j].getZone()!=map[i][j-1].getZone()) {
				if (waterGround(map[i][j],map[i][j-1])) {
					applyBlockZone(map[i][j], map[i][j-1], m_groundWaterZones, m_firstZone, m_numZones);
				}
				if (groundRubble(map[i][j], map[i][j-1])) {
					applyBlockZone(map[i][j], map[i][j-1], m_groundRubbleZones, m_firstZone, m_numZones);
				}
				if (groundCliff(map[i][j],map[i][j-1])) {
					applyBlockZone(map[i][j], map[i][j-1], m_groundCliffZones, m_firstZone, m_numZones);
				}
				if (crusherGround(map[i][j], map[i][j-1])) {
					applyBlockZone(map[i][j], map[i][j-1], m_crusherZones, m_firstZone, m_numZones);
				}
			}
			DEBUG_ASSERTCRASH(map[i][j].getZone() != 0, ("Cleared the zone."));
		}
	}
	
}

//
// Return the zone at this location.
//
UnsignedShort ZoneBlock::getEffectiveZone( LocomotorSurfaceTypeMask acceptableSurfaces, 
																					 Bool crusher, UnsignedShort zone) const
{
	DEBUG_ASSERTCRASH(zone, ("Zone not set"));
	if (acceptableSurfaces&LOCOMOTORSURFACE_AIR) return 1; // air is all zone 1.

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_GROUND) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_WATER) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_CLIFF)) {
		// Locomotors can go on ground, water & cliff, so all is zone 1.
		return 1; 
	}
	if (m_numZones<2) {
		return m_firstZone; // if we only got 1 zone, it's all the same zone.
	}
	DEBUG_ASSERTCRASH(zone >=m_firstZone && zone < m_firstZone+m_numZones, ("Invalid range."));
	if (zone<m_firstZone || zone >= m_firstZone+m_numZones) {
		return m_firstZone;
	}
	zone -= m_firstZone;
	if (crusher) {
		zone = m_crusherZones[zone];
		DEBUG_ASSERTCRASH(zone >=m_firstZone && zone < m_firstZone+m_numZones, ("Invalid range."));
		zone -= m_firstZone;
	}

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_GROUND) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_CLIFF)) {
		// Locomotors can go on ground & cliff, so use the ground cliff combiner.
		zone = m_groundCliffZones[zone];
		DEBUG_ASSERTCRASH(zone >=m_firstZone && zone < m_firstZone+m_numZones, ("Invalid range."));
		return zone; 
	}

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_GROUND) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_WATER)) {
		// Locomotors can go on ground & water, so use the ground water combiner.
		zone = m_groundWaterZones[zone];
		DEBUG_ASSERTCRASH(zone >=m_firstZone && zone < m_firstZone+m_numZones, ("Invalid range."));
		return zone; 
	}

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_GROUND) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_RUBBLE)) {
		// Locomotors can go on ground & rubble, so use the ground rubble combiner.
		zone = m_groundRubbleZones[zone];
		return zone; 
	}

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_CLIFF) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_WATER)) {
		// Locomotors can go on ground & cliff, so use the ground cliff combiner.
		DEBUG_CRASH(("Cliff water only locomotor sets not supported yet.")); 
	}

	return zone+m_firstZone;
}


/* Allocate zone equivalency arrays large enough to hold m_maxZone entries.  If the arrays are already
large enough, just return. */
void ZoneBlock::allocateZones(void) 
{
	if (m_zonesAllocated>m_numZones && m_groundCliffZones!=NULL) {
		return;
	}
	freeZones();

	if (m_numZones==1) {
		return; // we don't need any zone equivalency tables.
	}
	
	if (m_zonesAllocated == 0) {
		m_zonesAllocated = 4;
	}
	while (m_zonesAllocated <= m_numZones) {
		m_zonesAllocated *= 2;
	}
	// pool[]ify
	m_groundCliffZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
	m_groundWaterZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
	m_groundRubbleZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
	m_crusherZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
}


//------------------------  PathfindZoneManager  -------------------------------
PathfindZoneManager::PathfindZoneManager() : m_maxZone(0), 
m_needToCalculateZones(false), 
m_groundCliffZones(NULL), 
m_groundWaterZones(NULL), 
m_groundRubbleZones(NULL), 
m_terrainZones(NULL), 
m_crusherZones(NULL), 
m_hierarchicalZones(NULL), 
m_blockOfZoneBlocks(NULL),
m_zoneBlocks(NULL),
m_zonesAllocated(0)
{		
	m_zoneBlockExtent.x = 0;
	m_zoneBlockExtent.y = 0;
}

PathfindZoneManager::~PathfindZoneManager()  
{
	freeZones();
	freeBlocks();
}

void PathfindZoneManager::freeZones() 
{
	if (m_groundCliffZones) {
		delete [] m_groundCliffZones;
		m_groundCliffZones = NULL;
	}
	if (m_groundWaterZones) {
		delete [] m_groundWaterZones;
		m_groundWaterZones = NULL;
	}
	if (m_groundRubbleZones) {
		delete [] m_groundRubbleZones;
		m_groundRubbleZones = NULL;
	}
	if (m_terrainZones) {
		delete [] m_terrainZones;
		m_terrainZones = NULL;
	}
	if (m_crusherZones) {
		delete [] m_crusherZones;
		m_crusherZones = NULL;
	}
	if (m_hierarchicalZones) {
		delete [] m_hierarchicalZones;
		m_hierarchicalZones = NULL;
	}
	m_zonesAllocated = 0;
}

void PathfindZoneManager::freeBlocks() 
{
	if (m_blockOfZoneBlocks) {
		delete [] m_blockOfZoneBlocks;
		m_blockOfZoneBlocks = NULL;
	}
	if (m_zoneBlocks) {
		delete [] m_zoneBlocks;
		m_zoneBlocks = NULL;
	}
	m_zoneBlockExtent.x = 0;
	m_zoneBlockExtent.y = 0;
}

/* Allocate zone equivalency arrays large enough to hold m_maxZone entries.  If the arrays are already
large enough, just return. */
void PathfindZoneManager::allocateZones(void) 
{
	if (m_zonesAllocated>m_maxZone && m_groundCliffZones!=NULL) {
		return;
	}
	freeZones();
	
	if (m_zonesAllocated == 0) {
		m_zonesAllocated = INITIAL_ZONES;
	}
	while (m_zonesAllocated <= m_maxZone) {
		m_zonesAllocated *= 2;
	}
	DEBUG_LOG(("Allocating zone tables of size %d\n", m_zonesAllocated));
	// pool[]ify
	m_groundCliffZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
	m_groundWaterZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
	m_groundRubbleZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
	m_terrainZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
	m_crusherZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
	m_hierarchicalZones = MSGNEW("PathfindZoneInfo") UnsignedShort[m_zonesAllocated];
}

/* Allocate zone blocks for hierarchical pathfinding.   */
void PathfindZoneManager::allocateBlocks(const IRegion2D &globalBounds) 
{
	freeBlocks();

	m_zoneBlockExtent.x = (globalBounds.hi.x-globalBounds.lo.x+1+ZONE_BLOCK_SIZE-1)/ZONE_BLOCK_SIZE;
	m_zoneBlockExtent.y = (globalBounds.hi.y-globalBounds.lo.y+1+ZONE_BLOCK_SIZE-1)/ZONE_BLOCK_SIZE;

	m_blockOfZoneBlocks = MSGNEW("PathfindZoneBlocks") ZoneBlock[(m_zoneBlockExtent.x)*(m_zoneBlockExtent.y)];
	m_zoneBlocks = MSGNEW("PathfindZoneBlocks") ZoneBlockP[m_zoneBlockExtent.x];
	Int i;
	for (i=0; i<m_zoneBlockExtent.x; i++) {
		m_zoneBlocks[i] = &m_blockOfZoneBlocks[i*(m_zoneBlockExtent.y)];
	}
}

void PathfindZoneManager::markZonesDirty(void)  ///< Called when the zones need to be recalculated.
{
	m_needToCalculateZones = true;
} 

void PathfindZoneManager::reset(void)  ///< Called when the map is reset.
{
	freeZones();
	freeBlocks();
} 

/**
 * Calculate zones.  A zone is an area of the same terrain - clear, water or cliff.
 * The utility of zones is that if current location and destiontion are in the same zone, 
 * you can successfully pathfind.
 * If you are a multiple terrain vehicle, like amphibious transport, the lookup is a little more
 * complicated.
 */
void PathfindZoneManager::calculateZones( PathfindCell **map, PathfindLayer layers[], const IRegion2D &globalBounds )
{
#ifdef DEBUG_QPF
#if defined(DEBUG_LOGGING) 
	__int64 startTime64;
	double timeToUpdate=0.0f;
	__int64 endTime64,freq64;
	QueryPerformanceFrequency((LARGE_INTEGER *)&freq64);
	QueryPerformanceCounter((LARGE_INTEGER *)&startTime64);
#endif
#endif


	m_maxZone = 1;	// we start using zone 0 as a flag.
	const Int maxZones=24000;
	UnsignedShort zoneEquivalency[maxZones];
	Int i, j;
	for (i=0; i<maxZones; i++) {
		zoneEquivalency[i] = i;
	}
	for (i=0; i<=LAYER_LAST; i++) {
		layers[i].setZone(0);
	}

	Int xCount = (globalBounds.hi.x-globalBounds.lo.x+1+ZONE_BLOCK_SIZE-1)/ZONE_BLOCK_SIZE;
	Int yCount = (globalBounds.hi.y-globalBounds.lo.y+1+ZONE_BLOCK_SIZE-1)/ZONE_BLOCK_SIZE;

	Int xBlock, yBlock;
	for (xBlock = 0; xBlock<xCount; xBlock++) {
		for (yBlock=0; yBlock<yCount; yBlock++) {
			IRegion2D bounds;
			bounds.lo.x = globalBounds.lo.x + xBlock*ZONE_BLOCK_SIZE;
			bounds.lo.y = globalBounds.lo.y + yBlock*ZONE_BLOCK_SIZE;
			bounds.hi.x = bounds.lo.x + ZONE_BLOCK_SIZE - 1; // bounds are inclusive.
			bounds.hi.y = bounds.lo.y + ZONE_BLOCK_SIZE - 1; // bounds are inclusive.
			if (bounds.hi.x > globalBounds.hi.x) {
				bounds.hi.x = globalBounds.hi.x;
			}
			if (bounds.hi.y > globalBounds.hi.y) {
				bounds.hi.y = globalBounds.hi.y;
			}
			if (bounds.lo.x>bounds.hi.x || bounds.lo.y>bounds.hi.y) {
				DEBUG_CRASH(("Incorrect bounds calculation. Logic error, fix me. jba."));
				continue;
			}
			m_zoneBlocks[xBlock][yBlock].setInteractsWithBridge(false);
			for( j=bounds.lo.y; j<=bounds.hi.y; j++ )	{
				for( i=bounds.lo.x; i<=bounds.hi.x; i++ )	{
					PathfindCell *cell = &map[i][j];
					cell->setZone(0);

					if (i>bounds.lo.x) {
						if (map[i][j].getType() == map[i-1][j].getType()) {
							applyZone(map[i][j], map[i-1][j], zoneEquivalency, m_maxZone);
						}
					}
					if (j>bounds.lo.y) {
						if (map[i][j].getType() == map[i][j-1].getType()) {
							applyZone(map[i][j], map[i][j-1], zoneEquivalency, m_maxZone);
						}
					}
					if (cell->getZone()==0) {
						cell->setZone(m_maxZone);
						m_maxZone++;
						if (m_maxZone>= maxZones) {
							DEBUG_CRASH(("Ran out of pathfind zones.  SERIOUS ERROR! jba."));
							break;
						}
					}
					if (cell->getConnectLayer() > LAYER_GROUND) {
 						m_zoneBlocks[xBlock][yBlock].setInteractsWithBridge(true);
					}
					
				}
			}
			//DEBUG_LOG(("Collapsed zones %d\n", m_maxZone));
 		}
	}

	Int totalZones = m_maxZone;
	if (totalZones>maxZones/2) {
		DEBUG_LOG(("Max zones %d\n", m_maxZone));
	}

	// Collapse the zones into a 1,2,3... sequence, removing collapsed zones.
	m_maxZone = 1;
	Int collapsedZones[maxZones];
	collapsedZones[0] = 0;
	for (i=1; i<totalZones; i++) {
		Int zone = zoneEquivalency[i];
		if (zone == i) {
			collapsedZones[i] = m_maxZone;
			++m_maxZone;
		}	else {
			collapsedZones[i] = collapsedZones[zone];
		}
	}
#ifdef DEBUG_QPF
#if defined(DEBUG_LOGGING)
	QueryPerformanceCounter((LARGE_INTEGER *)&endTime64);
	timeToUpdate = ((double)(endTime64-startTime64) / (double)(freq64));
	DEBUG_LOG(("Time to calculate first %f\n", timeToUpdate));
#endif
#endif
	// Now map the zones in the map back into the collapsed zones.
	for( j=globalBounds.lo.y; j<=globalBounds.hi.y; j++ )	{
		for( i=globalBounds.lo.x; i<=globalBounds.hi.x; i++ )	{
			map[i][j].setZone(collapsedZones[map[i][j].getZone()]);
			if (map[i][j].getZone()==0) {
				DEBUG_CRASH(("Zone not set cell %d, %d", i, j));
			}
		}
	}
	for (i=0; i<=LAYER_LAST; i++) {
		Int zone = collapsedZones[layers[i].getZone()];
		if (zone == 0) {
			zone = m_maxZone;
			m_maxZone++;
		}
		layers[i].setZone( zone );
		if (!layers[i].isUnused() && !layers[i].isDestroyed() && layers[i].getZone()==0) {
			DEBUG_CRASH(("Zone not set Layer %d", i));
		}
		layers[i].applyZone();
		if (!layers[i].isUnused() && !layers[i].isDestroyed()) {
			ICoord2D ndx;
			layers[i].getStartCellIndex(&ndx);
			setBridge(ndx.x, ndx.y, true);	
			layers[i].getEndCellIndex(&ndx);
			setBridge(ndx.x, ndx.y, true);	
		}
	}

	allocateZones();
	DEBUG_ASSERTCRASH(xBlock==m_zoneBlockExtent.x && yBlock==m_zoneBlockExtent.y, ("Inconsistent allocation - SERIOUS ERROR. jba"));
	for (xBlock=0; xBlock<xCount; xBlock++) {
		for (yBlock=0; yBlock<yCount; yBlock++) {
			IRegion2D bounds;
			bounds.lo.x = globalBounds.lo.x + xBlock*ZONE_BLOCK_SIZE;
			bounds.lo.y = globalBounds.lo.y + yBlock*ZONE_BLOCK_SIZE;
			bounds.hi.x = bounds.lo.x + ZONE_BLOCK_SIZE - 1; // bounds are inclusive.
			bounds.hi.y = bounds.lo.y + ZONE_BLOCK_SIZE - 1; // bounds are inclusive.
			if (bounds.hi.x > globalBounds.hi.x) {
				bounds.hi.x = globalBounds.hi.x;
			}
			if (bounds.hi.y > globalBounds.hi.y) {
				bounds.hi.y = globalBounds.hi.y;
			}
			if (bounds.lo.x>bounds.hi.x || bounds.lo.y>bounds.hi.y) {
				DEBUG_CRASH(("Incorrect bounds calculation. Logic error, fix me. jba."));
				continue;
			}
			m_zoneBlocks[xBlock][yBlock].blockCalculateZones(map, layers, bounds);
		}
	}

#ifdef DEBUG_QPF
#if defined(DEBUG_LOGGING) 
	QueryPerformanceCounter((LARGE_INTEGER *)&endTime64);
	timeToUpdate = ((double)(endTime64-startTime64) / (double)(freq64));
	DEBUG_LOG(("Time to calculate second %f\n", timeToUpdate));
#endif
#endif

	// Determine water/ground equivalent zones, and ground/cliff equivalent zones.
	for (i=0; i<m_zonesAllocated; i++) {
		m_groundCliffZones[i] = i;
		m_groundWaterZones[i] = i;
		m_groundRubbleZones[i] = i;
		m_terrainZones[i] = i;
		m_crusherZones[i] = i;
		m_hierarchicalZones[i] = i;
	}

	for( j=globalBounds.lo.y; j<=globalBounds.hi.y; j++ )	{
		for( i=globalBounds.lo.x; i<=globalBounds.hi.x; i++ )	{
			if ( (map[i][j].getConnectLayer() > LAYER_GROUND) && 
				(map[i][j].getType() == PathfindCell::CELL_CLEAR) ) {
				PathfindLayer *layer = layers + map[i][j].getConnectLayer();
				resolveZones(map[i][j].getZone(), layer->getZone(), m_hierarchicalZones, m_maxZone);
			}
			if (i>globalBounds.lo.x && map[i][j].getZone()!=map[i-1][j].getZone()) {
				if (map[i][j].getType() == map[i-1][j].getType()) {
					applyZone(map[i][j], map[i-1][j], m_hierarchicalZones, m_maxZone);
				}
				if (waterGround(map[i][j], map[i-1][j])) {
					applyZone(map[i][j], map[i-1][j], m_groundWaterZones, m_maxZone);
				}
				if (groundRubble(map[i][j], map[i-1][j])) {
					Int zone1 = map[i][j].getZone();
					Int zone2 = map[i-1][j].getZone();
					if (m_terrainZones[zone1] != m_terrainZones[zone2]) {
						//DEBUG_LOG(("Matching terrain zone %d to %d.\n", zone1, zone2));
					}
					applyZone(map[i][j], map[i-1][j], m_groundRubbleZones, m_maxZone);
				}
				if (groundCliff(map[i][j], map[i-1][j])) {
					applyZone(map[i][j], map[i-1][j], m_groundCliffZones, m_maxZone);
				}
				if (terrain(map[i][j], map[i-1][j])) {
					applyZone(map[i][j], map[i-1][j], m_terrainZones, m_maxZone);
				}
				if (crusherGround(map[i][j], map[i-1][j])) {
					applyZone(map[i][j], map[i-1][j], m_crusherZones, m_maxZone);
				}
			}
			if (j>globalBounds.lo.y && map[i][j].getZone()!=map[i][j-1].getZone()) {
				if (map[i][j].getType() == map[i][j-1].getType()) {
					applyZone(map[i][j], map[i][j-1], m_hierarchicalZones, m_maxZone);
				}
				if (waterGround(map[i][j],map[i][j-1])) {
					applyZone(map[i][j], map[i][j-1], m_groundWaterZones, m_maxZone);
				}
				if (groundRubble(map[i][j], map[i][j-1])) {
					Int zone1 = map[i][j].getZone();
					Int zone2 = map[i][j-1].getZone();
					if (m_terrainZones[zone1] != m_terrainZones[zone2]) {
						//DEBUG_LOG(("Matching terrain zone %d to %d.\n", zone1, zone2));
					}
					applyZone(map[i][j], map[i][j-1], m_groundRubbleZones, m_maxZone);
				}
				if (groundCliff(map[i][j],map[i][j-1])) {
					applyZone(map[i][j], map[i][j-1], m_groundCliffZones, m_maxZone);
				}
				if (terrain(map[i][j], map[i][j-1])) {
					applyZone(map[i][j], map[i][j-1], m_terrainZones, m_maxZone);
				}
				if (crusherGround(map[i][j], map[i][j-1])) {
					applyZone(map[i][j], map[i][j-1], m_crusherZones, m_maxZone);
				}
/* No diagonals.  jba.
				if (i>globalBounds.lo.x) {
					if (waterGround(map[i][j],map[i-1][j-1])) {
						applyZone(map[i][j], map[i-1][j-1], m_groundWaterZones, m_maxZone);
					}
					if (groundCliff(map[i][j],map[i-1][j-1])) {
						applyZone(map[i][j], map[i-1][j-1], m_groundCliffZones, m_maxZone);
					}
					if (terrain(map[i][j],map[i-1][j-1])) {
						applyZone(map[i][j], map[i-1][j-1], m_terrainZones, m_maxZone);
					}
				}
*/
			}
			DEBUG_ASSERTCRASH(map[i][j].getZone() != 0, ("Cleared the zone."));
		}
	}

	if (m_maxZone >= m_zonesAllocated) {
		RELEASE_CRASH("Pathfind allocation error - fatal. see jba.");
	}
	for (i=1; i<m_maxZone; i++) {
		// Flatten hierarchical zones.
		Int zone = m_hierarchicalZones[i];
		m_hierarchicalZones[i] = m_hierarchicalZones[zone];
	}
	flattenZones(m_groundCliffZones, m_hierarchicalZones, m_maxZone);
	flattenZones(m_groundWaterZones, m_hierarchicalZones, m_maxZone);
	flattenZones(m_groundRubbleZones, m_hierarchicalZones, m_maxZone);
	flattenZones(m_terrainZones, m_hierarchicalZones, m_maxZone);
	flattenZones(m_crusherZones, m_hierarchicalZones, m_maxZone);


#ifdef DEBUG_QPF
#if defined(DEBUG_LOGGING) 
	QueryPerformanceCounter((LARGE_INTEGER *)&endTime64);
	timeToUpdate = ((double)(endTime64-startTime64) / (double)(freq64));
	DEBUG_LOG(("Time to calculate zones %f, cells %d\n", timeToUpdate, (globalBounds.hi.x-globalBounds.lo.x)*(globalBounds.hi.y-globalBounds.lo.y)));
#endif
#endif
#if defined _DEBUG || defined _INTERNAL
	if (TheGlobalData->m_debugAI && false) 
	{
		extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
		RGBColor color;
		memset(&color, 0, sizeof(Color));
		addIcon(NULL, 0, 0, color);
		for( j=0; j<globalBounds.hi.y; j++ )	{
			for( i=0; i<globalBounds.hi.x; i++ )	{
				Int zone = map[i][j].getZone();
				//zone = m_terrainZones[zone];
				zone = m_groundCliffZones[zone];

				color.blue = (zone%3) * 0.5f;
				zone = zone/3;
				color.green = (zone%3) * 0.5f;
				zone = zone/3;
				color.red = (zone%3) * 0.5;
				Coord3D pos;
				pos.x = ((Real)i + 0.5f) * PATHFIND_CELL_SIZE_F;
				pos.y = ((Real)j + 0.5f) * PATHFIND_CELL_SIZE_F;
				pos.z = TheTerrainLogic->getLayerHeight( pos.x, pos.y, map[i][j].getLayer() ) + 0.5f;
				addIcon(&pos, PATHFIND_CELL_SIZE_F*0.8f, 500, color);
			}
		}
	}
#endif
	m_needToCalculateZones = false;
}

//
// Clear the passable flags.
//
void PathfindZoneManager::clearPassableFlags( ) 
{	Int blockX;
	Int blockY;
	for (blockX = 0; blockX<m_zoneBlockExtent.x; blockX++) {
		for (blockY = 0; blockY<m_zoneBlockExtent.y; blockY++) {
			m_zoneBlocks[blockX][blockY].setPassable(false);
		}
	}
}

//
// Set the passable flags.
//
void PathfindZoneManager::setAllPassable( ) 
{	Int blockX;
	Int blockY;
	for (blockX = 0; blockX<m_zoneBlockExtent.x; blockX++) {
		for (blockY = 0; blockY<m_zoneBlockExtent.y; blockY++) {
			m_zoneBlocks[blockX][blockY].setPassable(true);
		}
	}
}

//
// Set the passable flag for the block at this location.
//
void PathfindZoneManager::setPassable(Int cellX, Int cellY, Bool passable) 
{
	Int blockX = cellX/ZONE_BLOCK_SIZE;
	Int blockY = cellY/ZONE_BLOCK_SIZE;

	if (blockX<0 || blockX>=m_zoneBlockExtent.x) {
		DEBUG_CRASH(("Invalid block."));
		return;
	}
	if (blockY<0 || blockY>=m_zoneBlockExtent.y) {
		DEBUG_CRASH(("Invalid block."));
		return;
	}
	m_zoneBlocks[blockX][blockY].setPassable(passable);
}

//
// Get the passable flag for the block at this location.
//
Bool PathfindZoneManager::isPassable(Int cellX, Int cellY) const
{
	Int blockX = cellX/ZONE_BLOCK_SIZE;
	Int blockY = cellY/ZONE_BLOCK_SIZE;

	if (blockX<0 || blockX>=m_zoneBlockExtent.x) {
		DEBUG_CRASH(("Invalid block."));
		return false;
	}
	if (blockY<0 || blockY>=m_zoneBlockExtent.y) {
		DEBUG_CRASH(("Invalid block."));
		return false;
	}
	return m_zoneBlocks[blockX][blockY].isPassable();
}

//
// Get the passable flag for the block at this location.
//
Bool PathfindZoneManager::clipIsPassable(Int cellX, Int cellY) const
{
	Int blockX = cellX/ZONE_BLOCK_SIZE;
	Int blockY = cellY/ZONE_BLOCK_SIZE;

	if (blockX<0 || blockX>=m_zoneBlockExtent.x) {
		return false;
	}
	if (blockY<0 || blockY>=m_zoneBlockExtent.y) {
		return false;
	}
	return m_zoneBlocks[blockX][blockY].isPassable();
}

//
// Set the bridge flag for the block at this location.
//
void PathfindZoneManager::setBridge(Int cellX, Int cellY, Bool bridge) 
{
	Int blockX = cellX/ZONE_BLOCK_SIZE;
	Int blockY = cellY/ZONE_BLOCK_SIZE;

	if (blockX<0 || blockX>=m_zoneBlockExtent.x) {
		// DEBUG_CRASH(("Invalid block."));  Bridges can be off the playable grid, so don't crash. jba.
		return;
	}
	if (blockY<0 || blockY>=m_zoneBlockExtent.y) {
		// DEBUG_CRASH(("Invalid block."));  Bridges can be off the playable grid, so don't crash. jba.
		return;
	}
	m_zoneBlocks[blockX][blockY].setInteractsWithBridge(bridge);
}


//
// Set the bridge flag for the block at this location.
//
Bool PathfindZoneManager::interactsWithBridge(Int cellX, Int cellY) const
{
	Int blockX = cellX/ZONE_BLOCK_SIZE;
	Int blockY = cellY/ZONE_BLOCK_SIZE;

	if (blockX<0 || blockX>=m_zoneBlockExtent.x) {
		DEBUG_CRASH(("Invalid block."));
		return false;
	}
	if (blockY<0 || blockY>=m_zoneBlockExtent.y) {
		DEBUG_CRASH(("Invalid block."));
		return false;
	}
	return m_zoneBlocks[blockX][blockY].getInteractsWithBridge();
}


//
// Return the zone at this location.
//
UnsignedShort PathfindZoneManager::getBlockZone(LocomotorSurfaceTypeMask acceptableSurfaces, Bool crusher,Int cellX, Int cellY, PathfindCell **map) const
{
	PathfindCell *cell = &(map[cellX][cellY]); 
	Int blockX = cellX/ZONE_BLOCK_SIZE;
	Int blockY = cellY/ZONE_BLOCK_SIZE;

	if (blockX<0 || blockX>=m_zoneBlockExtent.x) {
		DEBUG_CRASH(("Invalid block."));
		return 0;
	}
	if (blockY<0 || blockY>=m_zoneBlockExtent.y) {
		DEBUG_CRASH(("Invalid block."));
		return 0;
	}
	UnsignedShort zone =  m_zoneBlocks[blockX][blockY].getEffectiveZone(acceptableSurfaces, crusher, cell->getZone());
	if (zone > m_maxZone) {
		DEBUG_CRASH(("Invalid zone."));
		return 0;
	}
	return zone;
}

//
// Return the zone at this location.
//
UnsignedShort PathfindZoneManager::getEffectiveTerrainZone(UnsignedShort zone) const
{
	return m_hierarchicalZones[m_terrainZones[zone]];
}

//
// Return the zone at this location.
//
UnsignedShort PathfindZoneManager::getEffectiveZone( LocomotorSurfaceTypeMask acceptableSurfaces, 
																										Bool crusher, UnsignedShort zone) const
{
	//DEBUG_ASSERTCRASH(zone, ("Zone not set"));
	if (zone>m_maxZone) {
		DEBUG_CRASH(("Invalid zone"));
		return (0);
	}
	if (zone>m_maxZone) {
		DEBUG_CRASH(("Invalid zone"));
		return (0);
	}
	if (acceptableSurfaces&LOCOMOTORSURFACE_AIR) return 1; // air is all zone 1.

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_GROUND) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_WATER) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_CLIFF)) {
		// Locomotors can go on ground, water & cliff, so all is zone 1.
		return 1; 
	}

	if (crusher) {
		zone = m_crusherZones[zone];
	}

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_GROUND) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_CLIFF)) {
		// Locomotors can go on ground & cliff, so use the ground cliff combiner.
		zone = m_groundCliffZones[zone];
		return zone; 
	}

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_GROUND) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_WATER)) {
		// Locomotors can go on ground & water, so use the ground water combiner.
		zone = m_groundWaterZones[zone];
		return zone; 
	}

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_GROUND) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_RUBBLE)) {
		// Locomotors can go on ground & rubble, so use the ground rubble combiner.
		zone = m_groundRubbleZones[zone];
		return zone; 
	}

	if ( (acceptableSurfaces&LOCOMOTORSURFACE_CLIFF) &&
			(acceptableSurfaces&LOCOMOTORSURFACE_WATER)) {
		// Locomotors can go on ground & cliff, so use the ground cliff combiner.
		DEBUG_CRASH(("Cliff water only locomotor sets not supported yet.")); 
	}
	zone = m_hierarchicalZones[zone];

	return zone;
}
//-------------------- PathfindLayer ----------------------------------------
PathfindLayer::PathfindLayer() : m_blockOfMapCells(NULL), m_layerCells(NULL), m_bridge(NULL),
// Added By Sadullah Nader
// Initializations inserted
m_destroyed(FALSE),
m_height(0),
m_width(0),
m_xOrigin(0),
m_yOrigin(0),
m_zone(0)
//
{
	m_startCell.x = -1;
	m_startCell.y = -1;
	m_endCell.x = -1;
	m_endCell.y = -1;
}

PathfindLayer::~PathfindLayer()  
{
	reset();
}

/**
 * Returns true if the layer is avaialble for use.
 */
void PathfindLayer::reset(void) 
{
	m_bridge = NULL;
	if (m_layerCells) {
		Int i, j;
		for (i=0; i<m_width; i++) {
			for (j=0; j<m_height; j++) {
				PathfindCell *cell = &m_layerCells[i][j];
				cell->reset();
			}
		}
		delete [] m_layerCells;
		m_layerCells = NULL;
	}
	if (m_blockOfMapCells) {
		delete [] m_blockOfMapCells;
		m_blockOfMapCells = NULL;
	}
	m_width = 0;
	m_height = 0;
	m_xOrigin = 0;
	m_yOrigin = 0;	 
	m_startCell.x = -1;
	m_startCell.y = -1;
	m_endCell.x = -1;
	m_endCell.y = -1;
	m_layer = LAYER_GROUND;
}

/**
 * Returns true if the layer is avaialble for use.
 */
Bool PathfindLayer::isUnused(void) 
{
	// Special case - wall layer is built from not a bridge.  jba.
	if (m_layer == LAYER_WALL && m_width>0) return false;

	if (m_bridge==NULL) return true;
	return false;
}



/**
 * Draws debug cell info.
 */
#if defined _DEBUG || defined _INTERNAL
void PathfindLayer::doDebugIcons(void) {
	if (isUnused()) return;
	extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
	// render AI debug information
	{
		Coord3D topLeftCorner;
		RGBColor color;
		color.red = color.green = color.blue = 0;	
		Coord3D center;
		center.x = (m_xOrigin+m_width/2)*PATHFIND_CELL_SIZE_F;
		center.y = (m_yOrigin+m_height/2)*PATHFIND_CELL_SIZE_F;
		center.z = 0;
		Real bridgeHeight = TheTerrainLogic->getLayerHeight(center.x , center.y, m_layer);
		if (m_layer == LAYER_WALL) {
			bridgeHeight = TheAI->pathfinder()->getWallHeight();
		}
		Bool showCells = TheGlobalData->m_debugAI==AI_DEBUG_CELLS;
		// show the pathfind grid
		for( int j=0; j<m_height; j++ )
		{
			topLeftCorner.y = (Real)(j+m_yOrigin) * PATHFIND_CELL_SIZE_F;

			for( int i=0; i<m_width; i++ )
			{
				topLeftCorner.x = (Real)(i+m_xOrigin) * PATHFIND_CELL_SIZE_F;
				
				color.red = color.green = color.blue = 0;	
				Bool empty = true;
				
				const PathfindCell *cell = &m_layerCells[i][j];
				if (cell)
				{
					if (cell->getConnectLayer()==LAYER_GROUND) {
							color.green = 1;
							color.blue = 1;
							empty = false;
					}	else if (cell->getType() == PathfindCell::CELL_IMPASSABLE) {
							color.red = color.green = color.blue = 1;
							empty = false;
					}	else if (cell->getType() == PathfindCell::CELL_CLIFF) {
							color.red = 1;
							empty = false;
					}	
				}
				if (showCells) {
					empty = true;
					color.red = color.green = color.blue = 0;	
					if (empty && cell) {
						if (cell->getFlags()!=PathfindCell::NO_UNITS) {
							empty = false;
							if (cell->getFlags() == PathfindCell::UNIT_GOAL) {
								color.red = 1;
							}	else if (cell->getFlags() == PathfindCell::UNIT_PRESENT_FIXED) {
								color.green = color.blue = color.red = 1;
							}	else if (cell->getFlags() == PathfindCell::UNIT_PRESENT_MOVING) {
								color.green = 1; 
							}	else {
								color.green = color.red = 1;
							}
						}
					}
				}
				if (!empty) {
					Coord3D loc;
					loc.x = topLeftCorner.x + PATHFIND_CELL_SIZE_F/2.0f;
					loc.y = topLeftCorner.y + PATHFIND_CELL_SIZE_F/2.0f;
					loc.z = bridgeHeight;
					addIcon(&loc, PATHFIND_CELL_SIZE_F*0.8f, 99, color);
				}
			}
		}

	}
}
#endif

/**
 * Sets the bridge & layer number for a layer.
 */
Bool PathfindLayer::init(Bridge *theBridge, PathfindLayerEnum layer)  
{
	if (m_bridge!=NULL) return false;
	m_bridge = theBridge;
	m_layer = layer;
	m_destroyed = false;
	return true;
}

/**
 * Allocates the pathfind cells for the bridge layer.
 */
void PathfindLayer::allocateCells(const IRegion2D *extent)
{
	if (m_bridge == NULL) return;
	Region2D bridgeBounds = *m_bridge->getBounds();
	Int maxX, maxY;
	m_xOrigin = REAL_TO_INT_FLOOR((bridgeBounds.lo.x-PATHFIND_CELL_SIZE/100)/PATHFIND_CELL_SIZE);
	m_yOrigin = REAL_TO_INT_FLOOR((bridgeBounds.lo.y-PATHFIND_CELL_SIZE/100)/PATHFIND_CELL_SIZE);
	m_width = 0;
	m_height = 0;
	maxX = REAL_TO_INT_CEIL((bridgeBounds.hi.x+PATHFIND_CELL_SIZE/100)/PATHFIND_CELL_SIZE);
	maxY = REAL_TO_INT_CEIL((bridgeBounds.hi.y+PATHFIND_CELL_SIZE/100)/PATHFIND_CELL_SIZE);
	// Pad with 1 extra;
	m_xOrigin--;
	m_yOrigin--;
	maxX++;
	maxY++;

	if (m_xOrigin < extent->lo.x) m_xOrigin = extent->lo.x;
	if (m_yOrigin < extent->lo.y) m_yOrigin = extent->lo.y;
	if (maxX > extent->hi.x) maxX = extent->hi.x;
	if (maxY > extent->hi.y) maxY = extent->hi.y;
	if (maxX <= m_xOrigin) return;
	if (maxY <= m_yOrigin) return;
	m_width = maxX - m_xOrigin;
	m_height = maxY - m_yOrigin;

	// Allocate cells.
	// pool[]ify
	m_blockOfMapCells = MSGNEW("PathfindMapCells") PathfindCell[m_width*m_height];
	m_layerCells = MSGNEW("PathfindMapCells") PathfindCellP[m_width];
	Int i;
	for (i=0; i<m_width; i++) {
		m_layerCells[i] = &m_blockOfMapCells[i*m_height];
	}
}

/**
 * Allocates the pathfind cells for the wall bridge layer.
 */
void PathfindLayer::allocateCellsForWallLayer(const IRegion2D *extent, ObjectID *wallPieces, Int numPieces)
{
	DEBUG_ASSERTCRASH(m_layer==LAYER_WALL, ("Wrong layer for wall."));
	if (m_layer != LAYER_WALL) return;
	Region2D bridgeBounds;

	Int i; 
	Bool first = true;
	for (i=0; i<numPieces; i++) {
		Object *obj = TheGameLogic->findObjectByID(wallPieces[i]);
		Region2D objBounds;
		if (obj==NULL) continue;
		obj->getGeometryInfo().get2DBounds(*obj->getPosition(), obj->getOrientation(), objBounds);
		if (first) {
			bridgeBounds = objBounds;
			first = false;
		} else {
			if (bridgeBounds.lo.x>objBounds.lo.x) bridgeBounds.lo.x = objBounds.lo.x;
			if (bridgeBounds.lo.y>objBounds.lo.y) bridgeBounds.lo.y = objBounds.lo.y;
			if (bridgeBounds.hi.x<objBounds.hi.x) bridgeBounds.hi.x = objBounds.hi.x;
			if (bridgeBounds.hi.y<objBounds.hi.y) bridgeBounds.hi.y = objBounds.hi.y;
		}
	}

	Int maxX, maxY;
	m_xOrigin = REAL_TO_INT_FLOOR((bridgeBounds.lo.x-PATHFIND_CELL_SIZE/100)/PATHFIND_CELL_SIZE);
	m_yOrigin = REAL_TO_INT_FLOOR((bridgeBounds.lo.y-PATHFIND_CELL_SIZE/100)/PATHFIND_CELL_SIZE);
	m_width = 0;
	m_height = 0;
	maxX = REAL_TO_INT_CEIL((bridgeBounds.hi.x+PATHFIND_CELL_SIZE/100)/PATHFIND_CELL_SIZE);
	maxY = REAL_TO_INT_CEIL((bridgeBounds.hi.y+PATHFIND_CELL_SIZE/100)/PATHFIND_CELL_SIZE);
	// Pad with 1 extra;
	m_xOrigin--;
	m_yOrigin--;
	maxX++;
	maxY++;

	if (m_xOrigin < extent->lo.x) m_xOrigin = extent->lo.x;
	if (m_yOrigin < extent->lo.y) m_yOrigin = extent->lo.y;
	if (maxX > extent->hi.x) maxX = extent->hi.x;
	if (maxY > extent->hi.y) maxY = extent->hi.y;
	if (maxX <= m_xOrigin) return;
	if (maxY <= m_yOrigin) return;
	m_width = maxX - m_xOrigin;
	m_height = maxY - m_yOrigin;

	// Allocate cells.
	m_blockOfMapCells = MSGNEW("PathfindMapCells") PathfindCell[m_width*m_height];
	m_layerCells = MSGNEW("PathfindMapCells") PathfindCellP[m_width];

	for (i=0; i<m_width; i++) {
		m_layerCells[i] = &m_blockOfMapCells[i*m_height];
	}
}

/**
 * Checks to see if a broken bridge connects 2 zones.
 */
Bool PathfindLayer::connectsZones(PathfindZoneManager *zm, const LocomotorSet& locoSet,
																	Int zone1, Int zone2)
{
	if (!m_destroyed) {
		return false;
	}
	Bool found1 = false;
	Bool found2 = false;
	Int i, j;
	for (i=0; i<m_width; i++) {
		for (j=0; j<m_height; j++) {
			PathfindCell *cell = &m_layerCells[i][j];
			if (cell->getConnectLayer()==LAYER_GROUND) {
					PathfindCell *groundCell = TheAI->pathfinder()->getCell(LAYER_GROUND, i+m_xOrigin, j+m_yOrigin);
					DEBUG_ASSERTCRASH(groundCell, ("Should have cell."));
					if (groundCell) {
						UnsignedShort zone = zm->getEffectiveZone(locoSet.getValidSurfaces(),
							true, groundCell->getZone());
						zone = zm->getEffectiveTerrainZone(zone);
						if (zone == zone1) found1 = true;
						if (zone == zone2) found2 = true;
					}
			}
		}
	}
	return found1 && found2;
}

/**
 * Classifies the pathfind cells for the bridge layer.
 */
void PathfindLayer::classifyCells()
{
	m_startCell.x = -1;
	m_startCell.y = -1;
	m_endCell.x = -1;
	m_endCell.y = -1;
	Int i, j;
	for (i=0; i<m_width; i++) {
		for (j=0; j<m_height; j++) {
			PathfindCell *cell = &m_layerCells[i][j];
			cell->setConnectLayer(LAYER_INVALID);
			cell->setLayer(m_layer);
			classifyLayerMapCell(i+m_xOrigin, j+m_yOrigin, cell, m_bridge);	
		}
		BridgeInfo info;
		m_bridge->getBridgeInfo(&info);
		Coord3D bridgeDir = info.to;
		bridgeDir.x -= info.from.x;
		bridgeDir.y -= info.from.y;
		bridgeDir.z -= info.from.z;
		bridgeDir.normalize();
		bridgeDir.x *= PATHFIND_CELL_SIZE_F*0.7f;
		bridgeDir.y *= PATHFIND_CELL_SIZE_F*0.7f;

		m_startCell.x = REAL_TO_INT_FLOOR((info.from.x-bridgeDir.x) / PATHFIND_CELL_SIZE_F);
		m_startCell.y = REAL_TO_INT_FLOOR((info.from.y-bridgeDir.y) / PATHFIND_CELL_SIZE_F);
		m_endCell.x = REAL_TO_INT_FLOOR((info.to.x+bridgeDir.x) / PATHFIND_CELL_SIZE_F);
		m_endCell.y = REAL_TO_INT_FLOOR((info.to.y+bridgeDir.y) / PATHFIND_CELL_SIZE_F);
	}
	if (m_destroyed) {
		Int i, j;
		for (i=0; i<m_width; i++) {
			for (j=0; j<m_height; j++) {
				PathfindCell *cell = &m_layerCells[i][j];
				if (cell->getConnectLayer() == LAYER_GROUND) {
					PathfindCell *groundCell = TheAI->pathfinder()->getCell(LAYER_GROUND, i+m_xOrigin, j+m_yOrigin);
					DEBUG_ASSERTCRASH(groundCell, ("Should have cell."));
					if (groundCell) {
						DEBUG_ASSERTCRASH(groundCell->getConnectLayer()==m_layer, ("Should connect to this layer.jba."));
						groundCell->setConnectLayer(LAYER_INVALID); // disconnect it.
					}
				}
				cell->setType(PathfindCell::CELL_IMPASSABLE);
			}
		}
	}
}

/**
 * Classifies the pathfind cells for the wall bridge layer.
 */
void PathfindLayer::classifyWallCells(ObjectID *wallPieces, Int numPieces)
{
	DEBUG_ASSERTCRASH(m_layer==LAYER_WALL, ("Wrong layer for wall."));
	if (m_layer != LAYER_WALL) return;
	if (m_layerCells == NULL) return;

	Int i, j;
	for (i=0; i<m_width; i++) {
		for (j=0; j<m_height; j++) {
			PathfindCell *cell = &m_layerCells[i][j];
			cell->setConnectLayer(LAYER_INVALID);
			cell->setLayer(m_layer);
			classifyWallMapCell(i+m_xOrigin, j+m_yOrigin, cell, wallPieces, numPieces);	
			cell->setPinched(false);
		}
	}
	if (m_destroyed) {
		Int i, j;
		for (i=0; i<m_width; i++) {
			for (j=0; j<m_height; j++) {
				PathfindCell *cell = &m_layerCells[i][j];
				if (cell->getConnectLayer() == LAYER_GROUND) {
					PathfindCell *groundCell = TheAI->pathfinder()->getCell(LAYER_GROUND, i+m_xOrigin, j+m_yOrigin);
					DEBUG_ASSERTCRASH(groundCell, ("Should have cell."));
					if (groundCell) {
						DEBUG_ASSERTCRASH(groundCell->getConnectLayer()==m_layer, ("Should connect to this layer.jba."));
						groundCell->setConnectLayer(LAYER_INVALID); // disconnect it.
					}
				}
				cell->setType(PathfindCell::CELL_IMPASSABLE);
			}
		}
	}

	// Tighten up 1 cell.
	for (i=1; i<m_width-1; i++) {
		for (j=1; j<m_height-1; j++) {
			PathfindCell *cell = &m_layerCells[i][j];
			Int k, l;
			for (k=i-1; k<i+2; k++) {
				for (l=j-1; l<j+2; l++) {
					PathfindCell *adjacentCell = &m_layerCells[k][l];
					if (adjacentCell->getType() != PathfindCell::CELL_CLEAR) {
						cell->setPinched(true);
					}
				}
			}
		}
	}
	for (i=0; i<m_width; i++) {
		for (j=0; j<m_height; j++) {
			PathfindCell *cell = &m_layerCells[i][j];
			if (cell->getPinched() && cell->getType() == PathfindCell::CELL_CLEAR) {
				cell->setType(PathfindCell::CELL_CLIFF);
			}
			cell->setPinched(false);
		}
	}
}

/**
 * Relassifies the pathfind cells for the destroyed bridge layer.
 */
Bool PathfindLayer::setDestroyed(Bool destroyed)
{
	if (destroyed == m_destroyed) return false;
	
	m_destroyed = destroyed;
	classifyCells();

	return true;
}

/**
 * Copies m_zone into the zone for all the member cells.
 */
void PathfindLayer::applyZone( void )
{
	Int i, j;
	for (i=0; i<m_width; i++) {
		for (j=0; j<m_height; j++) {
			PathfindCell *cell = &m_layerCells[i][j];
			cell->setZone(m_zone);
		}
	}
}


/**
 * Return the bridge's object id.
 */
ObjectID PathfindLayer::getBridgeID(void)
{
	return m_bridge->peekBridgeInfo()->bridgeObjectID;
}

/**
 * Return the cell at the index location.
 */
PathfindCell *PathfindLayer::getCell(Int x, Int y)
{
	DEBUG_ASSERTCRASH(m_layerCells, ("no data in layer, why get cells?"));
	if (m_layerCells==NULL) {
		return NULL;
	}
	x -= m_xOrigin;
	y -= m_yOrigin;
	if (x<0 || x>=m_width) return NULL;
	if (y<0 || y>=m_height) return NULL;
	PathfindCell *cell = &m_layerCells[x][y];
	if (cell->getType() == PathfindCell::CELL_IMPASSABLE) {
		return NULL; // Impassable cells are ignored.
	}
	return cell;
}



/**
 * Classify the given map cell as clear, or not, etc.
 */
void PathfindLayer::classifyLayerMapCell( Int i, Int j , PathfindCell *cell, Bridge *theBridge)
{
	Coord3D topLeftCorner, bottomRightCorner;

	topLeftCorner.y = (Real)j * PATHFIND_CELL_SIZE_F;
	bottomRightCorner.y = topLeftCorner.y + PATHFIND_CELL_SIZE_F;

	topLeftCorner.x = (Real)i * PATHFIND_CELL_SIZE_F;
	bottomRightCorner.x = topLeftCorner.x + PATHFIND_CELL_SIZE_F;


	Int bridgeCount = 0;
	Coord3D pt;
	if (theBridge->isPointOnBridge(&topLeftCorner) ) {
		bridgeCount++;
	}
	pt = topLeftCorner;
	pt.y = bottomRightCorner.y;
	if (theBridge->isPointOnBridge(&pt) ) {
		bridgeCount++;
	}
	if (theBridge->isPointOnBridge(&bottomRightCorner) ) {
		bridgeCount++;
	}
	pt = topLeftCorner;
	pt.x = bottomRightCorner.x;
	if (theBridge->isPointOnBridge(&pt) ) {
		bridgeCount++;
	}
	cell->reset( );
	cell->setLayer(m_layer);
	cell->setType(PathfindCell::CELL_IMPASSABLE);
	if (bridgeCount == 4) {
		cell->setType(PathfindCell::CELL_CLEAR);
	} else {
		if (bridgeCount!=0) {
			cell->setType(PathfindCell::CELL_CLIFF); // it's off the bridge.
		}
		
		// check against the end lines.

		Region2D cellBounds;
		cellBounds.lo.x = topLeftCorner.x;
		cellBounds.lo.y = topLeftCorner.y;
		cellBounds.hi.x = bottomRightCorner.x;
		cellBounds.hi.y = bottomRightCorner.y;

		if (m_bridge->isCellOnEnd(&cellBounds)) {
			cell->setType(PathfindCell::CELL_CLEAR);
		}
		if (m_bridge->isCellOnSide(&cellBounds)) {
			cell->setType(PathfindCell::CELL_CLIFF);
		} else {
			if (m_bridge->isCellEntryPoint(&cellBounds)) {
				cell->setType(PathfindCell::CELL_CLEAR);
				cell->setConnectLayer(LAYER_GROUND);
				PathfindCell *groundCell = TheAI->pathfinder()->getCell(LAYER_GROUND, i, j );
				groundCell->setConnectLayer(cell->getLayer());
			}
		}
	}
	Coord3D center = topLeftCorner;
	center.x += PATHFIND_CELL_SIZE/2;
	center.y += PATHFIND_CELL_SIZE/2;
	if (cell->getType()!=PathfindCell::CELL_IMPASSABLE) {
		if (!(cell->getConnectLayer()==LAYER_GROUND) ) {
			// Check for bridge clearance.  If the ground isn't 1 pathfind cells below, mark impassable.
			Real groundHeight = TheTerrainLogic->getLayerHeight( center.x, center.y, LAYER_GROUND );
			Real bridgeHeight = theBridge->getBridgeHeight( &center, NULL );
			if (groundHeight+LAYER_Z_CLOSE_ENOUGH_F > bridgeHeight) {
				PathfindCell *groundCell = TheAI->pathfinder()->getCell(LAYER_GROUND,i, j);
				if (!(groundCell->getType()==PathfindCell::CELL_OBSTACLE)) {
					groundCell->setType(PathfindCell::CELL_IMPASSABLE);
				}
			}
		}
	}
	return;
}


Bool PathfindLayer::isPointOnWall(ObjectID *wallPieces, Int numPieces, const Coord3D *pt)
{
	Int i; 
	for (i=0; i<numPieces; i++) {
		Object *obj = TheGameLogic->findObjectByID(wallPieces[i]);
		if (obj==NULL) continue;
		Real major = obj->getGeometryInfo().getMajorRadius();
		Real minor = (obj->getGeometryInfo().getGeomType() == GEOMETRY_SPHERE) ? obj->getGeometryInfo().getMajorRadius() : obj->getGeometryInfo().getMinorRadius();

		Real c = (Real)Cos(-obj->getOrientation());
		Real s = (Real)Sin(-obj->getOrientation());

		// convert to a delta relative to rect ctr
		Real ptx = pt->x - obj->getPosition()->x;
		Real pty = pt->y - obj->getPosition()->y;

		// inverse-rotate it to the right coord system
		Real ptx_new = (Real)fabs(ptx*c - pty*s);
		Real pty_new = (Real)fabs(ptx*s + pty*c);

		if (ptx_new <= major && pty_new <= minor)
		{
			return true;
		}
	}
	return false;
}


/**
 * Classify the given map cell as clear, or not, etc.
 */
void PathfindLayer::classifyWallMapCell( Int i, Int j , PathfindCell *cell, ObjectID *wallPieces, Int numPieces)
{
	Coord3D topLeftCorner, bottomRightCorner;

	topLeftCorner.y = (Real)j * PATHFIND_CELL_SIZE_F;
	bottomRightCorner.y = topLeftCorner.y + PATHFIND_CELL_SIZE_F;

	topLeftCorner.x = (Real)i * PATHFIND_CELL_SIZE_F;
	bottomRightCorner.x = topLeftCorner.x + PATHFIND_CELL_SIZE_F;


	Int bridgeCount = 0;
	Coord3D pt;
	if (isPointOnWall(wallPieces, numPieces, &topLeftCorner) ) {
		bridgeCount++;
	}
	pt = topLeftCorner;
	pt.y = bottomRightCorner.y;
	if (isPointOnWall(wallPieces, numPieces, &pt) ) {
		bridgeCount++;
	}
	if (isPointOnWall(wallPieces, numPieces, &bottomRightCorner) ) {
		bridgeCount++;
	}
	pt = topLeftCorner;
	pt.x = bottomRightCorner.x;
	if (isPointOnWall(wallPieces, numPieces, &pt) ) {
		bridgeCount++;
	}
	cell->reset( );
	cell->setLayer(m_layer);
	cell->setType(PathfindCell::CELL_IMPASSABLE);
	if (bridgeCount == 4) {
		cell->setType(PathfindCell::CELL_CLEAR);
	} else {
		if (bridgeCount!=0) {
			cell->setType(PathfindCell::CELL_CLIFF); // it's off the bridge.
		}
		
	}
}

//----------------------- Pathfinder ---------------------------------------

Pathfinder::Pathfinder( void ) :m_map(NULL)
{
	debugPath = NULL;
	PathfindCellInfo::allocateCellInfos();
	reset();
}

Pathfinder::~Pathfinder( void )
{
	PathfindCellInfo::releaseCellInfos();
}

void Pathfinder::reset( void )
{
	frameToShowObstacles = 0;
	DEBUG_LOG(("Pathfind cell is %d bytes, PathfindCellInfo is %d bytes\n", sizeof(PathfindCell), sizeof(PathfindCellInfo)));

	if (m_blockOfMapCells) {
		delete []m_blockOfMapCells;
		m_blockOfMapCells = NULL;
	}
	if (m_map) {	 
		delete [] m_map;
		m_map = NULL;
	}

	Int i;
	for (i=0; i<=LAYER_LAST; i++) {
		m_layers[i].reset();
	}

	// reset the pathfind grid
	m_extent.lo.x=m_extent.lo.y=m_extent.hi.x=m_extent.hi.y=0;
	m_logicalExtent.lo.x=m_logicalExtent.lo.y=m_logicalExtent.hi.x=m_logicalExtent.hi.y=0;
	m_openList = NULL;
	m_closedList = NULL;

	m_ignoreObstacleID = INVALID_ID;
	m_isTunneling = false;

	m_moveAlliesDepth = 0;

	// pathfind grid cells have not been classified yet
	m_isMapReady = false;
	m_cumulativeCellsAllocated = 0;

	debugPathPos.x = 0.0f;
	debugPathPos.y = 0.0f;
	debugPathPos.z = 0.0f;

	if (debugPath)
		debugPath->deleteInstance();

	debugPath = NULL;
	m_frameToShowObstacles = 0;

	for (m_queuePRHead=0; m_queuePRHead<PATHFIND_QUEUE_LEN; m_queuePRHead++) {
		m_queuedPathfindRequests[m_queuePRHead] = INVALID_ID;
	}
	m_queuePRHead = 0;
	m_queuePRTail = 0;

	m_numWallPieces = 0;
	for (i=0; i<MAX_WALL_PIECES; ++i)
	{
		m_wallPieces[i] = INVALID_ID;
	}

	if (TheAI && TheAI->getAiData()) {
		m_wallHeight = TheAI->getAiData()->m_wallHeight;
	}
	else
	{
		m_wallHeight = 0.0f;
	}
	m_zoneManager.reset();
}

/** 
 * Adds a piece of a wall. 
 */
void Pathfinder::addWallPiece(Object *wallPiece)
{
	if (m_numWallPieces<MAX_WALL_PIECES-1) {
		m_wallPieces[m_numWallPieces] = wallPiece->getID();
		m_numWallPieces++;
	}
}

/**
 * Removes a piece of a wall
 */
void Pathfinder::removeWallPiece(Object *wallPiece)
{

	// sanity
  if( wallPiece == NULL )
		return;

	// find entry
	for( Int i = 0; i < m_numWallPieces; ++i )
	{

		// match by id
		if( m_wallPieces[ i ] == wallPiece->getID() )
		{

			// put the last id in the wall piece array here
			m_wallPieces[ i ] = m_wallPieces[ m_numWallPieces - 1 ];

			// we now have one less entry
			m_numWallPieces--;

			// all done
			return;

		}  // end if

	}  // end for, i

}  // end removeWallPiece

/** 
 * Checks if a point is on the wall. 
 */
Bool Pathfinder::isPointOnWall(const Coord3D *pos)
{
	if (m_numWallPieces==0) return false;
	if (m_layers[LAYER_WALL].isUnused()) return false;
	PathfindLayerEnum layer = (PathfindLayerEnum)LAYER_WALL;
	PathfindCell *cell = getCell(layer, pos);
	// make sure the layer matches, since getCell can return ground layer cells if the pos is 'off' the bridge/wall
	if (cell && cell->getLayer() == layer) {
		if (cell->getType() == PathfindCell::CELL_CLEAR) {
			return true;
		}
	}
	return false;
}

/** 
 * Adds a bridge & returns the layer. 
 */
PathfindLayerEnum Pathfinder::addBridge(Bridge *theBridge)
{
	Int layer = LAYER_GROUND+1;
	while (layer<=LAYER_WALL) {
		if (m_layers[layer].isUnused()) {
			if (m_layers[layer].init(theBridge, (PathfindLayerEnum)layer) ) {
				return (PathfindLayerEnum)layer;
			}
			DEBUG_LOG(("WARNING: Bridge failed to init in pathfinder\n"));
			return LAYER_GROUND; // failed to init, usually cause off of the map.  jba.
		}
		layer++;
	}
	DEBUG_CRASH(("Ran out of bridge layers."));
	return LAYER_GROUND;
}

/** 
 * Updates an object's layer, making sure the object is actually on the bridge first. 
 */
void Pathfinder::updateLayer(Object *obj, PathfindLayerEnum layer)
{
	if (layer != LAYER_GROUND) {
		if (!TheTerrainLogic->objectInteractsWithBridgeLayer(obj, layer)) {
			layer = LAYER_GROUND;
		}
	}
	//DEBUG_LOG(("Object layer is %d\n", layer));
	obj->setLayer(layer);
}

/** 
 * Classify the cells under the given object
 * If 'insert' is true, object is being added 
 * If 'insert' is false, object is being removed 
 */
void Pathfinder::classifyFence( Object *obj, Bool insert )
{
	m_zoneManager.markZonesDirty();
	
	const Coord3D *pos = obj->getPosition();
  Real angle = obj->getOrientation();
 
 	Real halfsizeX = obj->getTemplate()->getFenceWidth()/2;
 	Real halfsizeY = PATHFIND_CELL_SIZE_F/10.0f;
 	Real fenceOffset = obj->getTemplate()->getFenceXOffset();

 	Real c = (Real)Cos(angle);
 	Real s = (Real)Sin(angle);
 		
 	const Real STEP_SIZE = PATHFIND_CELL_SIZE_F * 0.5f;	// in theory, should be PATHFIND_CELL_SIZE_F exactly, but needs to be smaller to avoid aliasing problems
 	Real ydx = s * STEP_SIZE;
 	Real ydy = -c * STEP_SIZE;
 	Real xdx = c * STEP_SIZE;
 	Real xdy = s * STEP_SIZE;

 	Int numStepsX = REAL_TO_INT_CEIL(2.0f * halfsizeX / STEP_SIZE);
 	Int numStepsY = REAL_TO_INT_CEIL(2.0f * halfsizeY / STEP_SIZE);

 	Real tl_x = pos->x - fenceOffset*c - halfsizeY*s;
 	Real tl_y = pos->y + halfsizeY*c - fenceOffset*s;

 	for (Int iy = 0; iy < numStepsY; ++iy, tl_x += ydx, tl_y += ydy)
 	{
 		Real x = tl_x;
 		Real y = tl_y;
 		for (Int ix = 0; ix < numStepsX; ++ix, x += xdx, y += xdy)
 		{
 			Int cx = REAL_TO_INT_FLOOR((x + 0.5f)/PATHFIND_CELL_SIZE_F);
 			Int cy = REAL_TO_INT_FLOOR((y + 0.5f)/PATHFIND_CELL_SIZE_F);
 			if (cx >= 0 && cy >= 0 && cx < m_extent.hi.x && cy < m_extent.hi.y)
 			{
 				if (insert) {
 					ICoord2D pos;
 					pos.x = cx;
 					pos.y = cy;
 					m_map[cx][cy].setTypeAsObstacle( obj, true, pos );
 				}
 				else
 					m_map[cx][cy].removeObstacle(obj);
 			}
 			
 		}
 	}

#if 0 
	// Perhaps it would make more sense to use the iteratecellsalongpath() provided in this class,
	// but this way works well and is very traceable
	// neither one is true Bresenham
	// this one assumes zero fence thickness

	const Coord3D *fencePos = obj->getPosition();
	Coord3D fenceNorm;
	obj->getUnitDirectionVector2D( fenceNorm );
	Coord3D halfLength = fenceNorm;
	halfLength.scale( obj->getGeometryInfo().getMajorRadius() );

	Coord3D head = *fencePos;
	head.add( &halfLength );
	Coord3D tail = *fencePos;
	tail.sub( &halfLength );

	Real stepLength = 1.0f / ((halfLength.length()*2.0f) / PATHFIND_CELL_SIZE_F);

	for ( Real t = 0.0f; t <= 1.0f; t += stepLength )
	{
		Real lengthWalk_x = (head.x * t) + (tail.x * (1.0f-t));
		Real lengthWalk_y = (head.y * t) + (tail.y * (1.0f-t));

		Int cx = REAL_TO_INT_FLOOR( lengthWalk_x / PATHFIND_CELL_SIZE_F );
		Int cy = REAL_TO_INT_FLOOR( lengthWalk_y / PATHFIND_CELL_SIZE_F );
		if (cx >= 0 && cy >= 0 && cx < m_extent.hi.x && cy < m_extent.hi.y)
		{
			if (insert) {
				ICoord2D pos = { cx, cy };
				m_map[cx][cy].setTypeAsObstacle( obj, true, pos );
			}
			else
				m_map[cx][cy].removeObstacle(obj);
		}
	}
#endif

}

/** 
 * Classify the cells under the given object
 * If 'insert' is true, object is being added 
 * If 'insert' is false, object is being removed 
 */
void Pathfinder::classifyObjectFootprint( Object *obj, Bool insert )
{
	if (obj->isKindOf(KINDOF_MINE)) {
		return;  // don't pathfind around mines.
	}

	if (obj->isKindOf(KINDOF_PROJECTILE)) {
		return;  // don't care about projectiles.
	}

	if (obj->isKindOf(KINDOF_BRIDGE_TOWER)) {
		return;  // It is important to not abuse bridge towers.
	}

	if (obj->getTemplate()->getFenceWidth() > 0.0f) 
	{
		if (!obj->isKindOf(KINDOF_DEFENSIVE_WALL))
		{
			classifyFence(obj, insert);
			return;
		}
	}

	if (!insert) {
		// Just in case, remove the object.  Remove checks that the object has been added before
		// removing, so it's safer to just remove it, as by the time some units "die", they've become
		// lifeless immobile husks of debris, but we still need to remove them.  jba.
		removeUnitFromPathfindMap(obj);
		if (obj->isKindOf(KINDOF_WALK_ON_TOP_OF_WALL)) { 
			if (!m_layers[LAYER_WALL].isUnused()) {
				Int i;
				ObjectID curID = obj->getID();
				for (i=0; i<m_numWallPieces; i++) {
					if (curID == m_wallPieces[i]) {
						m_wallPieces[i]=INVALID_ID;
					}
				}
				// Kill anybody on the wall.
				Object *obj;
				for (obj = TheGameLogic->getFirstObject(); obj; obj=obj->getNextObject()) {
					if (obj->getLayer() == LAYER_WALL) {
						if (m_layers[LAYER_WALL].isPointOnWall(&curID, 1, obj->getPosition())) 
						{
							// The object fell off the wall.
							// Destroy it.
							DamageInfo extraDamageInfo;
							extraDamageInfo.in.m_damageType = DAMAGE_FALLING;
							extraDamageInfo.in.m_deathType = DEATH_SPLATTED;
							extraDamageInfo.in.m_sourceID = obj->getID();
							extraDamageInfo.in.m_amount = HUGE_DAMAGE_AMOUNT;
							obj->attemptDamage(&extraDamageInfo);
						}
					}
				}
				// recalc the wall.
				m_layers[LAYER_WALL].classifyWallCells(m_wallPieces, m_numWallPieces);
			}
		}
	}
	if (!obj->isKindOf(KINDOF_STRUCTURE)) {
		return;  // Only path around structures.
	}
	if (obj->isMobile()) {
		return; // mobile aren't obstacles.
	}
	/// For now, all small objects will not be obstacles
	if (obj->getGeometryInfo().getIsSmall()) {
		return;
	}

	if (obj->getHeightAboveTerrain() > PATHFIND_CELL_SIZE_F) {
		return; // Don't add bounds that are up in the air.
	}
	internal_classifyObjectFootprint(obj, insert);
}

void Pathfinder::internal_classifyObjectFootprint( Object *obj, Bool insert )
{
	switch(obj->getGeometryInfo().getGeomType())
	{
		case GEOMETRY_BOX:
		{
			m_zoneManager.markZonesDirty();
			const Coord3D *pos = obj->getPosition();
			Real angle = obj->getOrientation();

			Real halfsizeX = obj->getGeometryInfo().getMajorRadius();
			Real halfsizeY = obj->getGeometryInfo().getMinorRadius();

			Real c = (Real)Cos(angle);
			Real s = (Real)Sin(angle);
				
			const Real STEP_SIZE = PATHFIND_CELL_SIZE_F * 0.5f;	// in theory, should be PATHFIND_CELL_SIZE_F exactly, but needs to be smaller to avoid aliasing problems
			Real ydx = s * STEP_SIZE;
			Real ydy = -c * STEP_SIZE;
			Real xdx = c * STEP_SIZE;
			Real xdy = s * STEP_SIZE;

			Int numStepsX = REAL_TO_INT_CEIL(2.0f * halfsizeX / STEP_SIZE);
			Int numStepsY = REAL_TO_INT_CEIL(2.0f * halfsizeY / STEP_SIZE);

			Real tl_x = pos->x - halfsizeX*c - halfsizeY*s;
			Real tl_y = pos->y + halfsizeY*c - halfsizeX*s;

			for (Int iy = 0; iy < numStepsY; ++iy, tl_x += ydx, tl_y += ydy)
			{
				Real x = tl_x;
				Real y = tl_y;
				for (Int ix = 0; ix < numStepsX; ++ix, x += xdx, y += xdy)
				{
					Int cx = REAL_TO_INT_FLOOR((x + 0.5f)/PATHFIND_CELL_SIZE_F);
					Int cy = REAL_TO_INT_FLOOR((y + 0.5f)/PATHFIND_CELL_SIZE_F);

					if (cx >= 0 && cy >= 0 && cx < m_extent.hi.x && cy < m_extent.hi.y)
					{
						if (insert) {
							ICoord2D pos;
							pos.x = cx;
							pos.y = cy;
							m_map[cx][cy].setTypeAsObstacle( obj, false, pos );
						}
						else
							m_map[cx][cy].removeObstacle(obj);
					}
				}
			}
		}
		break;

		case GEOMETRY_SPHERE:	// not quite right, but close enough
		case GEOMETRY_CYLINDER:
		{
			m_zoneManager.markZonesDirty();
			// fill in all cells that overlap as obstacle cells
			/// @todo This is a very inefficient circle-rasterizer
			ICoord2D topLeft, bottomRight;
			Coord2D center, delta;
			const Coord3D *pos = obj->getPosition();
			Real radius = obj->getGeometryInfo().getMajorRadius();
			Real r2, size;

			topLeft.x = REAL_TO_INT_FLOOR(0.5f + (pos->x - radius)/PATHFIND_CELL_SIZE_F)-1;
			topLeft.y = REAL_TO_INT_FLOOR(0.5f + (pos->y - radius)/PATHFIND_CELL_SIZE_F)-1;
			size = (radius/PATHFIND_CELL_SIZE_F);
			center.x = (pos->x/PATHFIND_CELL_SIZE_F);
			center.y = (pos->y/PATHFIND_CELL_SIZE_F);

			size += 0.4f;
			r2 = size*size;

			bottomRight.x = topLeft.x + 2*size + 2;
			bottomRight.y = topLeft.y + 2*size + 2;

			for( int j = topLeft.y; j < bottomRight.y; j++ )
			{
				for( int i = topLeft.x; i < bottomRight.x; i++ )
				{
					delta.x = i+0.5f - center.x;
					delta.y = j+0.5f - center.y;

					if (delta.x*delta.x + delta.y*delta.y <= r2)
					{
						if (i >= 0 && j >= 0 && i < m_extent.hi.x && j < m_extent.hi.y)
						{
							if (insert)	{
								ICoord2D pos;
								pos.x = i;
								pos.y = j;
								m_map[i][j].setTypeAsObstacle( obj, false, pos );
							}
							else
								m_map[i][j].removeObstacle( obj );
						}
					}
				} // for i
			} // for j
		} // cylinder
		break;
	} // switch
	Region2D bounds;
	Int i, j;
	obj->getGeometryInfo().get2DBounds(*obj->getPosition(), obj->getOrientation(), bounds);
	IRegion2D cellBounds;
	cellBounds.lo.x = REAL_TO_INT_FLOOR(bounds.lo.x/PATHFIND_CELL_SIZE_F)-1;
	cellBounds.lo.y = REAL_TO_INT_FLOOR(bounds.lo.y/PATHFIND_CELL_SIZE_F)-1;
	cellBounds.hi.x = REAL_TO_INT_CEIL(bounds.hi.x/PATHFIND_CELL_SIZE_F)+1;
	cellBounds.hi.y = REAL_TO_INT_CEIL(bounds.hi.y/PATHFIND_CELL_SIZE_F)+1;
	if (cellBounds.lo.x < m_extent.lo.x) {
		cellBounds.lo.x = m_extent.lo.x;
	}
	if (cellBounds.lo.y < m_extent.lo.y) {
		cellBounds.lo.y = m_extent.lo.y;
	}
	if (cellBounds.lo.y < m_extent.lo.y) {
		cellBounds.lo.y = m_extent.lo.y;
	}
	if (cellBounds.hi.x > m_extent.hi.x) {
		cellBounds.hi.x = m_extent.hi.x;
	}
	if (cellBounds.hi.y > m_extent.hi.y) {
		cellBounds.hi.y = m_extent.hi.y;
	}



	// Expand building bounds 1 cell.
#define no_EXPAND_ONE_CELL
#ifdef EXPAND_ONE_CELL
	for( j=cellBounds.lo.y; j<=cellBounds.hi.y; j++ )
	{
		for( i=cellBounds.lo.x; i<=cellBounds.hi.x; i++ )
		{
			if (!insert) {
				if (m_map[i][j].getType() == PathfindCell::CELL_IMPASSABLE) {
					m_map[i][j].setType(PathfindCell::CELL_CLEAR);
				}
				m_map[i][j].setPinched(false);
			}
			if (!insert) {
				if (m_map[i][j].isObstaclePresent(obj->getID())) {
					m_map[i][j].removeObstacle( obj );
				}
				continue;
			}
			if (m_map[i][j].getType() == PathfindCell::CELL_CLEAR) {
				Bool obstacleAdjacent = false;
				Int k, l;
				for (k=i-1; k<i+2; k++) {
					if (k<m_extent.lo.x || k> m_extent.hi.x) continue;
					for (l=j-1; l<j+2; l++) {
						if (l<m_extent.lo.y || l> m_extent.hi.y) continue;
						if ((k==i) && (l==j)) continue;
						if ((k!=i) && (l!=j)) continue;
						if (m_map[k][l].getType()!=PathfindCell::CELL_CLEAR)) {	
							objectAdjacent = true;
							break;
						}

					}
				}
				if (obstacleAdjacent) {
					m_map[i][j].setPinched(true);
				}
				// If the total open cells are < 2
			}
		}
	}	 

	if (insert) {
		for( j=cellBounds.lo.y; j<=cellBounds.hi.y; j++ )
		{
			for( i=cellBounds.lo.x; i<=cellBounds.hi.x; i++ )
			{
				if (m_map[i][j].getPinched() && m_map[i][j].getType() == PathfindCell::CELL_CLEAR) {
					ICoord2D pos;
					pos.x = i;
					pos.y = j;
					m_map[i][j].setTypeAsObstacle( obj, false, pos );
					//m_map[i][j].setType(PathfindCell::CELL_CLIFF);
					m_map[i][j].setPinched(false);
				}
			}
		}
	}
#endif



	if (!insert) {
		for( j=cellBounds.lo.y; j<=cellBounds.hi.y; j++ )
		{
			for( i=cellBounds.lo.x; i<=cellBounds.hi.x; i++ )
			{
				if (m_map[i][j].getType()==PathfindCell::CELL_IMPASSABLE) {
					m_map[i][j].setType(PathfindCell::CELL_CLEAR);
				}
			}
		}
	}
	// Check for pinched cells, and close them off.

	for( j=cellBounds.lo.y; j<=cellBounds.hi.y; j++ )
	{
		for( i=cellBounds.lo.x; i<=cellBounds.hi.x; i++ )
		{
			m_map[i][j].setPinched(false);
			if (m_map[i][j].getType() == PathfindCell::CELL_CLEAR) {
				Int totalCount = 0;
				Int orthogonalCount = 0;
				Int k, l;
				for (k=i-1; k<i+2; k++) {
					if (k<m_extent.lo.x || k> m_extent.hi.x) continue;
					for (l=j-1; l<j+2; l++) {
						if (l<m_extent.lo.y || l> m_extent.hi.y) continue;
						if ((k==i) && (j==l)) continue;
						if (m_map[k][l].getType() == PathfindCell::CELL_CLEAR) {
							totalCount++;
							if ((k==i) || (l==j)) {
								orthogonalCount++;
							}
						}

					}
				}
				// If the total open cells are < 2 or total cells < 4, we are pinched.
				if (orthogonalCount<2 || totalCount<4) {
					m_map[i][j].setPinched(true);
				}
			}
		}
	}

	for( j=cellBounds.lo.y; j<=cellBounds.hi.y; j++ )
	{
		for( i=cellBounds.lo.x; i<=cellBounds.hi.x; i++ )
		{
			if (m_map[i][j].getPinched() && (m_map[i][j].getType() == PathfindCell::CELL_CLEAR)) {
				m_map[i][j].setType(PathfindCell::CELL_IMPASSABLE);
				m_map[i][j].setPinched(false);
			}
		}
	}

	// Expand building bounds 1 cell.
#define MARK_BORDER_PINCHED
#ifdef MARK_BORDER_PINCHED
	for( j=cellBounds.lo.y; j<=cellBounds.hi.y; j++ )
	{
		for( i=cellBounds.lo.x; i<=cellBounds.hi.x; i++ )
		{
			if (m_map[i][j].getType() == PathfindCell::CELL_CLEAR) {
				Bool objectAdjacent = false;
				Int k, l;
				for (k=i-1; k<i+2; k++) {
					if (k<m_extent.lo.x || k> m_extent.hi.x) continue;
					for (l=j-1; l<j+2; l++) {
						if (l<m_extent.lo.y || l> m_extent.hi.y) continue;
						if ((k==i) && (l==j)) continue;
						if ((k!=i) && (l!=j)) continue;
						if (m_map[k][l].getType() == PathfindCell::CELL_OBSTACLE) {	
							objectAdjacent = true;
							break;
						}

					}
				}
				if (objectAdjacent) {
					m_map[i][j].setPinched(true);
				}
			}
		}
	}	
#endif



}

/**
 * Classify the given map cell as WATER, CLIFF, etc.
 * Note that this does NOT classify cells as OBSTACLES. 
 * OBSTACLE cells are classified only via objects.
 * @todo optimize this - lots of redundant computation
 */
void Pathfinder::classifyMapCell( Int i, Int j , PathfindCell *cell)
{
	Coord3D topLeftCorner, bottomRightCorner;


	Bool hasObstacle =  (cell->getType() == PathfindCell::CELL_OBSTACLE) ;

	topLeftCorner.y = (Real)j * PATHFIND_CELL_SIZE_F;
	bottomRightCorner.y = topLeftCorner.y + PATHFIND_CELL_SIZE_F;

	topLeftCorner.x = (Real)i * PATHFIND_CELL_SIZE_F;
	bottomRightCorner.x = topLeftCorner.x + PATHFIND_CELL_SIZE_F;

	cell->setPinched(false);

	PathfindCell::CellType type = PathfindCell::CELL_CLEAR;
	if (TheTerrainLogic->isCliffCell(topLeftCorner.x, topLeftCorner.y))
	{
		type = PathfindCell::CELL_CLIFF;
	}

	//
	// If any corners are underwater, this is a water cell
	//
	if (TheTerrainLogic->isUnderwater( topLeftCorner.x, topLeftCorner.y ) ) type = PathfindCell::CELL_WATER;
	if (TheTerrainLogic->isUnderwater( topLeftCorner.x, bottomRightCorner.y) ) type = PathfindCell::CELL_WATER;
	if (TheTerrainLogic->isUnderwater( bottomRightCorner.x, bottomRightCorner.y ) ) type = PathfindCell::CELL_WATER;
	if (TheTerrainLogic->isUnderwater( bottomRightCorner.x, topLeftCorner.y ) ) type = PathfindCell::CELL_WATER;

	if (hasObstacle) {
		type =  PathfindCell::CELL_OBSTACLE;
	}
	cell->setType( type );
	cell->releaseInfo();
}

/**
 * Set up for a new map.
 */
void Pathfinder::newMap( void )
{
	m_wallHeight = TheAI->getAiData()->m_wallHeight; // may be updated by map.ini.
	Region3D terrainExtent;
	TheTerrainLogic->getMaximumPathfindExtent( &terrainExtent );
	IRegion2D bounds;
	bounds.lo.x = REAL_TO_INT_FLOOR(terrainExtent.lo.x / PATHFIND_CELL_SIZE_F);
	bounds.hi.x = REAL_TO_INT_FLOOR(terrainExtent.hi.x / PATHFIND_CELL_SIZE_F);
	bounds.lo.y = REAL_TO_INT_FLOOR(terrainExtent.lo.y / PATHFIND_CELL_SIZE_F);
	bounds.hi.y = REAL_TO_INT_FLOOR(terrainExtent.hi.y / PATHFIND_CELL_SIZE_F);
	bounds.hi.x--;
	bounds.hi.y--;
	Bool dataAllocated = false;
	if (m_extent.hi.x==bounds.hi.x && m_extent.hi.y==bounds.hi.y) {
		if (m_blockOfMapCells != NULL && m_map!=NULL) {
			dataAllocated = true;
		}
	}
	// For map load from file, we have to call newMap twice to do sequencing issues.
	// so the second time through, dataAllocated==TRUE, so we skip the allocate.
	if (!dataAllocated) {
		m_extent = bounds;
		DEBUG_ASSERTCRASH(m_map == NULL, ("Can't reallocate pathfind cells."));
 		m_zoneManager.allocateBlocks(m_extent);
		// Allocate cells.
		m_blockOfMapCells = MSGNEW("PathfindMapCells") PathfindCell[(bounds.hi.x+1)*(bounds.hi.y+1)];
		m_map = MSGNEW("PathfindMapCells") PathfindCellP[bounds.hi.x+1];
		Int i;
		for (i=0; i<=bounds.hi.x; i++) {
			m_map[i] = &m_blockOfMapCells[i*(bounds.hi.y+1)];
		}
		for (i=0; i<LAYER_LAST; i++) {
			if (!m_layers[i].isUnused()) {
				m_layers[i].allocateCells(&m_extent);
			}
		}
		if (m_numWallPieces>0) {
			m_layers[LAYER_WALL].init(NULL, LAYER_WALL);
			m_layers[LAYER_WALL].allocateCellsForWallLayer(&m_extent, m_wallPieces, m_numWallPieces);
		}
	}
	classifyMap();
	// Add existing objects.
	Object *obj;
	for( obj = TheGameLogic->getFirstObject(); obj; obj = obj->getNextObject() )
	{
		classifyObjectFootprint(obj, true);
	}

	m_isMapReady = true;
}

/**
 * Classify all cells in grid as obstacles, etc.
 */
void Pathfinder::classifyMap(void)
{

	Int i, j;
	// for now, sample cell corners and classify cell accordingly
	for( j=m_extent.lo.y; j<=m_extent.hi.y; j++ )
	{
		for( i=m_extent.lo.x; i<=m_extent.hi.x; i++ )
		{
			classifyMapCell( i, j, &m_map[i][j]);
		}
	}
#if 1
	// Expand all cliff cells one step (mark pinched)
	for( j=m_extent.lo.y; j<=m_extent.hi.y; j++ )
	{
		for( i=m_extent.lo.x; i<=m_extent.hi.x; i++ )
		{
			if (m_map[i][j].getType() & PathfindCell::CELL_CLIFF) {
				Int k, l;
				for (k=i-1; k<i+2; k++) {
					if (k<m_extent.lo.x || k> m_extent.hi.x) continue;
					for (l=j-1; l<j+2; l++) {
						if (l<m_extent.lo.y || l> m_extent.hi.y) continue;
						if (m_map[k][l].getType() == PathfindCell::CELL_CLEAR) {
							m_map[k][l].setPinched(true);	
						}

					}
				}
			}
		}
	}
	// Convert pinched to cliff.
	for( j=m_extent.lo.y; j<=m_extent.hi.y; j++ )
	{
		for( i=m_extent.lo.x; i<=m_extent.hi.x; i++ )
		{
			if (m_map[i][j].getPinched()) {
				if (m_map[i][j].getType()==PathfindCell::CELL_CLEAR) {
					m_map[i][j].setType(PathfindCell::CELL_CLIFF);
				}
			}
		}
	}
	// Add a border of pinched cells to cliffs.
	for( j=m_extent.lo.y; j<=m_extent.hi.y; j++ )
	{
		for( i=m_extent.lo.x; i<=m_extent.hi.x; i++ )
		{
			if (m_map[i][j].getType() & PathfindCell::CELL_CLIFF) {
				Int k, l;
				for (k=i-1; k<i+2; k++) {
					if (k<m_extent.lo.x || k> m_extent.hi.x) continue;
					for (l=j-1; l<j+2; l++) {
						if (l<m_extent.lo.y || l> m_extent.hi.y) continue;
						if (m_map[k][l].getType() == PathfindCell::CELL_CLEAR) {
							m_map[k][l].setPinched(true);	
						}

					}
				}
			}
		}
	}
#endif
	for (i=0; i<LAYER_LAST; i++) {
		if (!m_layers[i].isUnused()) {
			m_layers[i].classifyCells();
		}
	}
	if (!m_layers[LAYER_WALL].isUnused()) {
		m_layers[LAYER_WALL].classifyWallCells(m_wallPieces, m_numWallPieces);
	}
	m_zoneManager.calculateZones(m_map, m_layers, m_extent);
}


/**
 * Force pathfind map recomputation.
 */
void Pathfinder::forceMapRecalculation( void )
{
	classifyMap( );
}

/**
 * Show all cells touched in the last search
 */
void Pathfinder::debugShowSearch(  Bool pathFound  )
{
	if (!TheGlobalData->m_debugAI) {
		return;
	}
#if defined _DEBUG || defined _INTERNAL
	extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);

	// show all explored cells for debugging
	PathfindCell *s;

		
	RGBColor color;
	color.red = color.blue = color.green = 1;
	if (!pathFound) {
		addIcon(NULL, 0, 0, color);	 // erase.
	}

	for( s = m_openList; s; s=s->getNextOpen() )
	{
		// create objects to show path - they decay
		RGBColor color;
		color.red = color.green = 0;
		color.blue = 1;

		Coord3D pos;
		pos.x = ((Real)s->getXIndex() + 0.5f) * PATHFIND_CELL_SIZE_F;
		pos.y = ((Real)s->getYIndex() + 0.5f) * PATHFIND_CELL_SIZE_F;
		pos.z = TheTerrainLogic->getLayerHeight( pos.x, pos.y, s->getLayer() ) + 0.5f;
		addIcon(&pos, PATHFIND_CELL_SIZE_F*.6f, 200, color);
	}

	for( s = m_closedList; s; s=s->getNextOpen() )
	{
		// create objects to show path - they decay
		// create objects to show path - they decay
		RGBColor color;
		color.red = color.blue = 1;
		color.green = 0;
		if (!pathFound)	color.blue = 0;

		Int length=200;
		if (!pathFound) 
			length *= 2;

		Coord3D pos;
		pos.x = ((Real)s->getXIndex() + 0.5f) * PATHFIND_CELL_SIZE_F;
		pos.y = ((Real)s->getYIndex() + 0.5f) * PATHFIND_CELL_SIZE_F;
		pos.z = TheTerrainLogic->getLayerHeight( pos.x, pos.y, s->getLayer()) + 0.5f;
		addIcon(&pos, PATHFIND_CELL_SIZE_F*.6f, length, color);
	}
#endif
}

Locomotor* Pathfinder::chooseBestLocomotorForPosition(PathfindLayerEnum layer, LocomotorSet* locomotorSet, const Coord3D* pos )
{
	Int x = REAL_TO_INT_FLOOR(pos->x/PATHFIND_CELL_SIZE);
	Int y = REAL_TO_INT_FLOOR(pos->y/PATHFIND_CELL_SIZE);
	PathfindCell* cell = getCell(layer, x, y );
	// off the map? call it CELL_CLEAR...
	PathfindCell::CellType celltype = cell ? cell->getType() : PathfindCell::CELL_CLEAR;

	LocomotorSurfaceTypeMask acceptableSurfaces = validLocomotorSurfacesForCellType(celltype);
	return locomotorSet->findLocomotor(acceptableSurfaces);
}

/*static*/ LocomotorSurfaceTypeMask Pathfinder::validLocomotorSurfacesForCellType(PathfindCell::CellType t)
{
	if (t == PathfindCell::CELL_OBSTACLE) {
		return LOCOMOTORSURFACE_AIR;
	}
	if (t == PathfindCell::CELL_IMPASSABLE) {
		return LOCOMOTORSURFACE_AIR;
	}
	if (t==PathfindCell::CELL_CLEAR) {
		return LOCOMOTORSURFACE_GROUND | LOCOMOTORSURFACE_AIR;
	}
	if (t == PathfindCell::CELL_WATER) {
		return LOCOMOTORSURFACE_WATER | LOCOMOTORSURFACE_AIR;
	}
	if (t == PathfindCell::CELL_RUBBLE) {
		return LOCOMOTORSURFACE_RUBBLE | LOCOMOTORSURFACE_AIR;
	}
	if ( (t == PathfindCell::CELL_CLIFF) ) {
		return LOCOMOTORSURFACE_CLIFF | LOCOMOTORSURFACE_AIR;
	}
	return NO_SURFACES;
}

//
// Return true if we can move onto this position
//
Bool Pathfinder::validMovementTerrain( PathfindLayerEnum layer, const Locomotor* locomotor, const Coord3D *pos)
{
	Int x = REAL_TO_INT_FLOOR(pos->x/PATHFIND_CELL_SIZE);
	Int y = REAL_TO_INT_FLOOR(pos->y/PATHFIND_CELL_SIZE);

	PathfindCell *toCell = NULL;
	toCell = getCell( layer, x, y );

	if (toCell == NULL)
		return false;
	// Only do terrain, not obstacle cells.  jba.
	if (toCell->getType()==PathfindCell::CELL_OBSTACLE) return true;
	if (toCell->getType()==PathfindCell::CELL_IMPASSABLE) return true;
	if (toCell->getLayer()!=LAYER_GROUND && toCell->getLayer() == PathfindCell::CELL_CLEAR) {
		return true; 
	}
	// check validity of destination cell
	LocomotorSurfaceTypeMask acceptableSurfaces = validLocomotorSurfacesForCellType(toCell->getType());
	if ((locomotor->getLegalSurfaces() & acceptableSurfaces) == 0)
		return false;
	return true;
}

//
// Releases the cells on the open & closed lists.
//
void Pathfinder::cleanOpenAndClosedLists(void) {
	Int count = 0;
	if (m_openList) {
		count += PathfindCell::releaseOpenList(m_openList);
		m_openList = NULL;
	}		 
	if (m_closedList) {
		count += PathfindCell::releaseClosedList(m_closedList);
		m_closedList = NULL;
	}		 
	m_cumulativeCellsAllocated += count;
//#ifdef _DEBUG
#if 0
	// Check for dangling cells.
	for( int j=0; j<=m_extent.hi.y; j++ )
		for( int i=0; i<=m_extent.hi.x; i++ )
			if (m_map[ i ][ j ].hasInfo()) {
				DEBUG_ASSERTCRASH((m_map[i][j].getXIndex()==i && m_map[i][j].getYIndex()==j), ("Wrong cell coordinates"));
				Bool needInfo = (m_map[ i ][ j ].getType() == PathfindCell::CELL_OBSTACLE);
				if (m_map[i][j].isAircraftGoal()) {
					needInfo = true;
				}
				if (m_map[i][j].getFlags() != PathfindCell::NO_UNITS)  {
					needInfo = true;
				}				
				if (!needInfo) {
					DEBUG_LOG(("leaked cell %d, %d\n", m_map[i][j].getXIndex(), m_map[i][j].getYIndex()));
					m_map[i][j].releaseInfo();
				}
				DEBUG_ASSERTCRASH((needInfo), ("Minor temporary memory leak - Extra cell allocated.  Tell JBA steps if repeatable."));
			};
	//DEBUG_LOG(("Pathfind used %d cells.\n", count));
#endif
//#endif

}


//
// Return true if we can move onto this position
//
Bool Pathfinder::validMovementPosition( Bool isCrusher, LocomotorSurfaceTypeMask acceptableSurfaces, 
																			 PathfindCell *toCell, PathfindCell *fromCell )
{
	if (toCell == NULL)
		return false;

	// check if the destination cell is classified as an obstacle,
	// and we happen to be ignoring it
	if (toCell->isObstaclePresent( m_ignoreObstacleID ))
		return true;

	if (isCrusher && toCell->isObstacleFence()) {
		return true;
	}

	// check validity of destination cell
	LocomotorSurfaceTypeMask cellSurfaces = validLocomotorSurfacesForCellType(toCell->getType());
	if ((cellSurfaces & acceptableSurfaces) == 0)
		return false;

#if 0	
	//
	// For diagonal moves, check neighboring vertical and horizontal
	// steps as well to avoid "squeezing through a crack".
	//
	if (fromCell)
	{
		ICoord2D delta;

		delta.x = toCell->getXIndex() - fromCell->getXIndex();
		delta.y = toCell->getYIndex() - fromCell->getYIndex();

		if (delta.x != 0 && delta.y != 0)
		{
			// test vertical movement
			PathfindCell *otherCell = getCell( toCell->getXIndex(), fromCell->getYIndex() );
			Bool open = true;

			// check if cell is on the map
			if (otherCell == NULL)
				open = false;

			// check if we can move onto this new cell
			if (validMovementPosition( locomotorSet, otherCell, fromCell ) == false)
				open = false;

			// test horizontal movement
			if (open == false)
			{
				otherCell = getCell( fromCell->getXIndex(), toCell->getYIndex() );

				// check if cell is on the map
				if (otherCell == NULL)
					return false;

				// check if we can move onto this new cell
				if (validMovementPosition( locomotorSet, otherCell, fromCell ) == false)
					return false;
			}
		}
	}
#endif

	return true;
}

/**
 * Checks to see if obj can occupy the pathfind cell at x,y.
 * Returns false if there is another unit's goal already there.
 * Assumes your locomotor already said you can go there.
 */
Bool Pathfinder::checkDestination(const Object *obj, Int cellX, Int cellY, PathfindLayerEnum layer, Int iRadius, Bool centerInCell)
{
	// If obj==NULL, means we are checking for any ground units present.  jba.
	Int numCellsAbove = iRadius;
	if (centerInCell) numCellsAbove++;
	Bool checkForAircraft = false;
	Int i, j;
	ObjectID ignoreId = INVALID_ID;
	ObjectID objID = INVALID_ID;
	if (obj && obj->getAIUpdateInterface()) {
		ignoreId =  obj->getAIUpdateInterface()->getIgnoredObstacleID();
		checkForAircraft = obj->getAI()->isAircraftThatAdjustsDestination();
		objID = obj->getID();
	}
	for (i=cellX-iRadius; i<cellX+numCellsAbove; i++) {
		for (j=cellY-iRadius; j<cellY+numCellsAbove; j++) {
			PathfindCell	*cell = getCell(layer, i, j);
			if (cell) {
				if (checkForAircraft) {
					if (!cell->isAircraftGoal()) continue;
					if (cell->getGoalAircraft()==objID) continue;
					return false;
				}
				if (cell->getType()==PathfindCell::CELL_OBSTACLE) {
					if (cell->isObstaclePresent( ignoreId ))
						continue;
					return false;
				}
				if (cell->getFlags() == PathfindCell::NO_UNITS) {
					continue;  // Nobody is here, so it's ok.
				} 
				ObjectID goalUnitID = cell->getGoalUnit();
				if (goalUnitID==objID) {
					continue; // we got it.
				} else if (ignoreId==goalUnitID) {
					continue; // we are ignoring it.
				} else if (goalUnitID!=INVALID_ID) {
					if (obj==NULL) {
						return false;
					}
					Object *unit = TheGameLogic->findObjectByID(goalUnitID);
					if (unit) {
						// order matters: we want to know if I consider it to be an ally, not vice versa
						if (obj->getRelationship(unit) == ALLIES) {
							return false; 	// Don't usurp your allies goals.  jba.
						}	
						if (cell->getFlags()==PathfindCell::UNIT_PRESENT_FIXED) {
							Bool canCrush = obj->canCrushOrSquish(unit, TEST_CRUSH_OR_SQUISH);
							if (!canCrush) {
								return false; // Don't move to an occupied cell.
							}							
						}
					}
				}
			} else {
				return false; // off the map, so can't place here.
			}
		}
	}	

	return true;
}

/**
 * Checks to see if obj can move through the pathfind cell at x,y.
 * Returns false if there are other units already there.
 * Assumes your locomotor already said you can go there.
 */
Bool Pathfinder::checkForMovement(const Object *obj, TCheckMovementInfo &info)	  
{
	info.allyFixedCount = 0;
	info.allyMoving = false;
	info.allyGoal = false;
	info.enemyFixed = false;

	const Int		maxAlly = 5;
	ObjectID		allies[maxAlly];
	Int					numAlly = 0;

	if (!obj) return true; // not object can move there.
	ObjectID ignoreId = INVALID_ID;
	if (obj->getAIUpdateInterface()) {
		ignoreId =  obj->getAIUpdateInterface()->getIgnoredObstacleID();
	}

	Int numCellsAbove = info.radius;
	if (info.centerInCell) numCellsAbove++;
	Int i, j;
//	Bool isInfantry = obj->isKindOf(KINDOF_INFANTRY);
	for (i=info.cell.x-info.radius; i<info.cell.x+numCellsAbove; i++) {
		for (j=info.cell.y-info.radius; j<info.cell.y+numCellsAbove; j++) {
			PathfindCell	*cell = getCell(info.layer,i, j);
			if (cell) {
				enum PathfindCell::CellFlags flags = cell->getFlags();
				ObjectID posUnit = cell->getPosUnit();
				if ((flags == PathfindCell::UNIT_GOAL) || (flags == PathfindCell::UNIT_GOAL_OTHER_MOVING)) {
					info.allyGoal = true;
				}
				if (flags == PathfindCell::NO_UNITS) {
					continue;  // Nobody is here, so it's ok.
				} else if (posUnit==obj->getID()) {
					continue; // we got it.
				} else if (posUnit==ignoreId) {
					continue; // we are ignoring this one.
				}	else {
					Bool check = false;
					Object *unit = NULL;
					if (flags==PathfindCell::UNIT_PRESENT_MOVING || flags==PathfindCell::UNIT_GOAL_OTHER_MOVING) {
						unit = TheGameLogic->findObjectByID(posUnit);
						// order matters: we want to know if I consider it to be an ally, not vice versa
						if (unit && obj->getRelationship(unit) == ALLIES) {
							info.allyMoving = true;
						}
						if (info.considerTransient) {
							check = true;
						}
					}
					if (flags == PathfindCell::UNIT_PRESENT_FIXED) {
						check = true;
						unit = TheGameLogic->findObjectByID(posUnit);
					}
					if (check && unit!=NULL) {
						if (obj->getAIUpdateInterface() && obj->getAIUpdateInterface()->getIgnoredObstacleID()==unit->getID()) {
							// Don't check if it's the ignored obstacle.
							check = false;
						}
					}
					if (check && unit) {
#ifdef INFANTRY_MOVES_THROUGH_INFANTRY
						if (obj->isKindOf(KINDOF_INFANTRY) && unit->isKindOf(KINDOF_INFANTRY)) {
							// Infantry can run through infantry.
							continue; // 
						}
#endif
						// See if it is an ally.
						// order matters: we want to know if I consider it to be an ally, not vice versa
						if (obj->getRelationship(unit) == ALLIES) {
							if (!unit->getAIUpdateInterface()) {
								return false; // can't path through not-idle units.
							}
							if (!unit->getAIUpdateInterface()->isIdle()) {
								return false; // can't path through not-idle units.
							}
							Bool found = false;
							Int k;
							for (k=0; k<numAlly; k++) {
								if (allies[k] == unit->getID()) {
									found = true;
								}
							}
							if (!found) {
								info.allyFixedCount++;
								if (numAlly < maxAlly) {
									allies[numAlly] = unit->getID();
									numAlly++;
								}
							}
						}	else {
							Bool canCrush = obj->canCrushOrSquish( unit, TEST_CRUSH_OR_SQUISH );
							if (!canCrush) {
								info.enemyFixed = true;
							}
						}
					}
				}
			} else {
				return false; // off the map, so can't place here.
			}
		}
	}
	return true;
}

/**
 * Adjusts a coordinate to the center of it's cell.
 */
// Snaps the current position to it's grid location.
void Pathfinder::snapPosition(Object *obj, Coord3D *pos)
{
	Int iRadius;
	Bool center;
	getRadiusAndCenter(obj, iRadius, center);
	ICoord2D cell;
	Coord3D adjustDest = *pos;
	if (!center) {
		adjustDest.x += PATHFIND_CELL_SIZE_F/2;
		adjustDest.y += PATHFIND_CELL_SIZE_F/2;
	}
	worldToCell( &adjustDest, &cell );
	adjustCoordToCell(cell.x, cell.y,  center, *pos, LAYER_GROUND);
}

/**
 * Adjusts a goal position to the center of it's cell.
 */
// Snaps the current position to it's grid location.
void Pathfinder::snapClosestGoalPosition(Object *obj, Coord3D *pos)
{
	Int iRadius;
	Bool center;
	getRadiusAndCenter(obj, iRadius, center);
	ICoord2D cell;
	Coord3D adjustDest = *pos;
	if (!center) {
		adjustDest.x += PATHFIND_CELL_SIZE_F/2;
		adjustDest.y += PATHFIND_CELL_SIZE_F/2;
	}
	PathfindLayerEnum layer = TheTerrainLogic->getLayerForDestination(pos);
	worldToCell( &adjustDest, &cell );
	adjustCoordToCell(cell.x, cell.y,  center, *pos, LAYER_GROUND);
	if (checkDestination(obj, cell.x, cell.y , layer, iRadius, center)) {
		return;
	}

	// Try adjusting by 1.
	Int i,j;
	for (i=cell.x-1; i<cell.x+2; i++) {
		for (j=cell.y-1; j<cell.y+2; j++) {
			if (checkDestination(obj, i, j, layer, iRadius, center)) {
				adjustCoordToCell(i, j,  center, *pos, layer);
				return;
			}
		}
	}
	if (iRadius==0) {
		// Try to find an unoccupied cell.
		for (i=cell.x-1; i<cell.x+2; i++) {
			for (j=cell.y-1; j<cell.y+2; j++) {
				PathfindCell	*newCell = getCell(layer,i, j);
				if (newCell) {
					if (newCell->getGoalUnit()==INVALID_ID || newCell->getGoalUnit()==obj->getID()) {
						adjustCoordToCell(i, j,  center, *pos, layer);
						return;
					}
				}
			}
		}
		// Try to find an unoccupied cell.
		for (i=cell.x-1; i<cell.x+2; i++) {
			for (j=cell.y-1; j<cell.y+2; j++) {
				PathfindCell	*newCell = getCell(layer,i, j);
				if (newCell) {
					if (newCell->getFlags()!=PathfindCell::UNIT_PRESENT_FIXED) {
						adjustCoordToCell(i, j,  center, *pos, layer);
						return;
					}
				}
			}
		}
	}
	//DEBUG_LOG(("Couldn't find goal.\n"));
}

/** 
 * Returns coordinates of goal.
 *
 */
Bool Pathfinder::goalPosition(Object *obj, Coord3D *pos)
{
	Int iRadius;
	Bool center;
	AIUpdateInterface *ai = obj->getAIUpdateInterface();
	if (!ai) return false; // only consider ai objects.
	getRadiusAndCenter(obj, iRadius, center);
	ICoord2D cell = *ai->getPathfindGoalCell();
	pos->zero();
	if (cell.x<0 || cell.y<0) return false;
	adjustCoordToCell(cell.x, cell.y,  center, *pos, LAYER_GROUND);
	return true;
}

 
Bool Pathfinder::checkForAdjust(Object *obj, const LocomotorSet& locomotorSet, Bool isHuman,
																Int cellX, Int cellY, PathfindLayerEnum layer, 
																Int iRadius, Bool center, Coord3D *dest, const Coord3D *groupDest) 
{
	Coord3D adjustDest;
	PathfindCell *cellP = getCell(layer, cellX, cellY);
	if (cellP==NULL) return false;
	if (cellP && cellP->getType() == PathfindCell::CELL_CLIFF) {
		return false;  // no final destinations on cliffs.
	}
	if (isHuman) {
		// check if new cell is in logical map.	(computer can move off logical map)
		if (cellX < m_logicalExtent.lo.x ||
				cellY < m_logicalExtent.lo.y || 
				cellX > m_logicalExtent.hi.x || 
				cellY > m_logicalExtent.hi.y) return false; 
	}
	if (checkDestination(obj, cellX, cellY, layer, iRadius, center)) {
		adjustCoordToCell(cellX, cellY,  center, adjustDest, cellP->getLayer());
		Bool pathExists;
		Bool adjustedPathExists;
		if (obj->isKindOf(KINDOF_AIRCRAFT)) {
			pathExists = true;
			adjustedPathExists = true;
		}	else {
			pathExists = quickDoesPathExist( locomotorSet, obj->getPosition(), dest);
			adjustedPathExists = quickDoesPathExist( locomotorSet, obj->getPosition(), &adjustDest);
			if (!pathExists) {	
				if (quickDoesPathExist( locomotorSet, dest, &adjustDest))	{
 					adjustedPathExists = true;
				}
			}
		}
		if ( adjustedPathExists	) {
			if (groupDest) {
				tightenPath(obj, locomotorSet, &adjustDest, groupDest);
				// Check to see if it is a long way to get to the adjusted destination.
				Int cost = checkPathCost(obj, locomotorSet, groupDest, &adjustDest);
				Int dx = IABS(groupDest->x-adjustDest.x);
				Int dy = IABS(groupDest->y-adjustDest.y);
				if (1.4f*(dx+dy)<cost) {
					return false; 
				}
			}			
			*dest = adjustDest;
			return true;
		}
	}
	return false;
}

Bool Pathfinder::checkForLanding(Int cellX, Int cellY, PathfindLayerEnum layer, 
																Int iRadius, Bool center, Coord3D *dest) 
{
	Coord3D adjustDest;
	PathfindCell *cellP = getCell(layer, cellX, cellY);
	if (cellP==NULL) return false;
	switch (cellP->getType())
	{
		case PathfindCell::CELL_CLIFF:
		case PathfindCell::CELL_WATER:
		case PathfindCell::CELL_IMPASSABLE:
			return false;  // no final destinations on cliffs, water, etc.
	}
	if (checkDestination(NULL, cellX, cellY, layer, iRadius, center)) {
		adjustCoordToCell(cellX, cellY,  center, adjustDest, cellP->getLayer());
		*dest = adjustDest;
		return true;
	}
	return false;
}

/**
 * Find an unoccupied spot for a unit to land at.
 * Returns false if there are no spots available within a reasonable radius.
 */
Bool Pathfinder::adjustToLandingDestination(Object *obj, Coord3D *dest)
{
	Int iRadius;
	Bool center;
	getRadiusAndCenter(obj, iRadius, center);
	ICoord2D cell;
	Coord3D adjustDest = *dest;

	Region3D extent;
	TheTerrainLogic->getMaximumPathfindExtent(&extent);
	// If the object is off the map & the goal is off the map, it is a scripted setup, so just
	// go to the dest.
	if (!extent.isInRegionNoZ(dest)) {
		if (!extent.isInRegionNoZ(obj->getPosition())) {
			return true;
		}
	}

	if (!center) {
		adjustDest.x += PATHFIND_CELL_SIZE_F/2;
		adjustDest.y += PATHFIND_CELL_SIZE_F/2;
	}
	worldToCell( &adjustDest, &cell );

	enum {MAX_CELLS_TO_TRY=400};
	Int limit = MAX_CELLS_TO_TRY; 
	Int i, j;
	i = cell.x;
	j = cell.y;
	PathfindLayerEnum layer = TheTerrainLogic->getLayerForDestination(dest);
	if (checkForLanding(i,j, layer, iRadius, center, dest)) {
		return true;
	}

	Int delta=1;
	Int count;
	while (limit>0) {
		for (count = delta; count>0; count--) {
			i++;
			limit--;
			if (checkForLanding(i,j, layer, iRadius, center, dest)) {
				return true;
			}
		}
		for (count = delta; count>0; count--) {
			j++;
			limit--;
			if (checkForLanding(i,j, layer, iRadius, center, dest)) {
				return true;
			}
		}
		delta++;
		for (count = delta; count>0; count--) {
			i--;
			limit--;
			if (checkForLanding(i,j, layer, iRadius, center, dest)) {
				return true;
			}
		}
		for (count = delta; count>0; count--) {
			j--;
			limit--;
			if (checkForLanding(i,j, layer, iRadius, center, dest)) {
				return true;
			}
		}
		delta++;
	}
	return false;
}	




/**
 * Find an unoccupied spot for a unit to move to.
 * Returns false if there are no spots available within a reasonable radius.
 */
Bool Pathfinder::adjustDestination(Object *obj, const LocomotorSet& locomotorSet, Coord3D *dest, const Coord3D *groupDest)
{
	if( obj->isKindOf(KINDOF_PROJECTILE) )
	{
		return true; // missiles can go wherever they want to. jba.
	}

	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}
	Int iRadius;
	Bool center;
	getRadiusAndCenter(obj, iRadius, center);
	ICoord2D cell;
	Coord3D adjustDest = *dest;
	if (!center) {
		adjustDest.x += PATHFIND_CELL_SIZE_F/2;
		adjustDest.y += PATHFIND_CELL_SIZE_F/2;
	}
	worldToCell( &adjustDest, &cell );
	PathfindLayerEnum layer = TheTerrainLogic->getLayerForDestination(dest);
	if (groupDest) {
		layer = TheTerrainLogic->getLayerForDestination(groupDest);
	}

	enum {MAX_CELLS_TO_TRY=400};
	Int limit = MAX_CELLS_TO_TRY; 
	Int i, j;
	i = cell.x;
	j = cell.y;
	if (checkForAdjust(obj, locomotorSet, isHuman, i,j, layer, iRadius, center, dest, groupDest)) {
		return true;
	}

	Int delta=1;
	Int count;
	while (limit>0) {
		for (count = delta; count>0; count--) {
			i++;
			limit--;
			if (checkForAdjust(obj, locomotorSet, isHuman, i,j, layer, iRadius, center, dest, groupDest)) {
				return true;
			}
		}
		for (count = delta; count>0; count--) {
			j++;
			limit--;
			if (checkForAdjust(obj, locomotorSet, isHuman, i,j, layer, iRadius, center, dest, groupDest)) {
				return true;
			}
		}
		delta++;
		for (count = delta; count>0; count--) {
			i--;
			limit--;
			if (checkForAdjust(obj, locomotorSet, isHuman, i,j, layer, iRadius, center, dest, groupDest)) {
				return true;
			}
		}
		for (count = delta; count>0; count--) {
			j--;
			limit--;
			if (checkForAdjust(obj, locomotorSet, isHuman, i,j, layer, iRadius, center, dest, groupDest)) {
				return true;
			}
		}
		delta++;
	}
	if (groupDest) {
		// Didn't work, so just do simple adjust.
		return(adjustDestination(obj, locomotorSet, dest, NULL));
	}
	//DEBUG_LOG(("adjustDestination failed, dest (%f, %f), adj dest (%f,%f), %x %s\n", dest->x, dest->y, adjustDest.x, adjustDest.y,
		//obj, obj->getTemplate()->getName().str()));
	return false;
}

Bool Pathfinder::checkForTarget(const Object *obj, 	Int cellX, Int cellY, const Weapon *weapon,
																const Object *victim, const Coord3D *victimPos,
																Int iRadius, Bool center,Coord3D *dest) 
{
	Coord3D adjustDest;
	if (checkDestination(obj, cellX, cellY, LAYER_GROUND, iRadius, center)) {
		adjustCoordToCell(cellX, cellY,  center, adjustDest, LAYER_GROUND);
		if (weapon->isGoalPosWithinAttackRange( obj, &adjustDest, victim, victimPos ))	{
			*dest = adjustDest;
			return true;
		}
	}
	return false;
}

/**
 * Find an unoccupied spot for a unit to move to that can fire at victim.
 * Returns false if there are no spots available within a reasonable radius.
 */
Bool Pathfinder::adjustTargetDestination(const Object *obj, const Object *target, const Coord3D *targetPos, 
																				 const Weapon *weapon, Coord3D *dest)
{
	Int iRadius;
	Bool center;
	getRadiusAndCenter(obj, iRadius, center);
	ICoord2D cell;
	Coord3D adjustDest = *dest;
	if (!center) {
		adjustDest.x += PATHFIND_CELL_SIZE_F/2;
		adjustDest.y += PATHFIND_CELL_SIZE_F/2;
	}
	if (worldToCell( &adjustDest, &cell )) {
		return false; // outside of bounds.
	}
	enum {MAX_CELLS_TO_TRY=400};
	Int limit = MAX_CELLS_TO_TRY; 
	Int i, j;
	i = cell.x;
	j = cell.y;
	if (checkForTarget(obj, i,j, weapon, target, targetPos, iRadius, center, dest)) {
		return true;
	}

	Int delta=1;
	Int count;
	while (limit>0) {
		for (count = delta; count>0; count--) {
			i++;
			limit--;
			if (checkForTarget(obj, i,j, weapon, target, targetPos, iRadius, center, dest)) {
				return true;
			}
		}
		for (count = delta; count>0; count--) {
			j++;
			limit--;
			if (checkForTarget(obj, i,j, weapon, target, targetPos, iRadius, center, dest)) {
				return true;
			}
		}
		delta++;
		for (count = delta; count>0; count--) {
			i--;
			limit--;
			if (checkForTarget(obj, i,j, weapon, target, targetPos, iRadius, center, dest)) {
				return true;
			}
		}
		for (count = delta; count>0; count--) {
			j--;
			limit--;
			if (checkForTarget(obj, i,j, weapon, target, targetPos, iRadius, center, dest)) {
				return true;
			}
		}
		delta++;
	}
	return false;
}

Bool Pathfinder::checkForPossible(Bool isCrusher, Int fromZone,  Bool center, const LocomotorSet& locomotorSet, 
																	Int cellX, Int cellY, PathfindLayerEnum layer, Coord3D *dest, Bool startingInObstacle) 
{
	PathfindCell *goalCell = getCell(layer, cellX, cellY);
	if (!goalCell) return false;
	if (goalCell->getType() == PathfindCell::CELL_OBSTACLE) return false;
	Int zone2 =  m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), isCrusher, goalCell->getZone());
	if (startingInObstacle) {
		zone2 = m_zoneManager.getEffectiveTerrainZone(zone2);
	}
	if (fromZone==zone2) {
		adjustCoordToCell(cellX, cellY,  center, *dest, layer);
		return true;
	}
	return false;
}

/**
 * Find a pathable spot near the destination.
 * Returns false if there are no spots available within a reasonable radius.
 */
Bool Pathfinder::adjustToPossibleDestination(Object *obj, const LocomotorSet& locomotorSet, 
																						 Coord3D *dest)
{
	Int radius;
	Bool center;
	getRadiusAndCenter(obj, radius, center);
	ICoord2D goalCellNdx;
	Coord3D adjustDest = *dest;
	if (!center) {
		adjustDest.x += PATHFIND_CELL_SIZE_F/2;
		adjustDest.y += PATHFIND_CELL_SIZE_F/2;
	}
	if (worldToCell( &adjustDest, &goalCellNdx )) {
		return false; // outside of bounds.
	}

	// determine goal cell
	PathfindCell *goalCell;
	PathfindLayerEnum destinationLayer = TheTerrainLogic->getLayerForDestination(dest);
	
	goalCell = getCell(destinationLayer, goalCellNdx.x, goalCellNdx.y);


	Coord3D from = *obj->getPosition();

	// determine start cell
	ICoord2D startCellNdx;
	worldToCell(&from, &startCellNdx);
	PathfindLayerEnum layer = LAYER_GROUND;
	if (obj) {
		layer = obj->getLayer();
	}
	PathfindCell *parentCell = getClippedCell( layer, &from );
	if (parentCell == NULL) {
		return false;
	}

	//
	Int zone1, zone2;
	Bool isCrusher = obj ? obj->getCrusherLevel() > 0 : false;
	zone1 = m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), isCrusher, parentCell->getZone()); 
	Bool isObstacle = false;
	if (parentCell->getType() == PathfindCell::CELL_OBSTACLE)	{
		isObstacle = true;
	}
	if (isObstacle) {
		zone1 = m_zoneManager.getEffectiveTerrainZone(zone1);
		zone1 = m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), isCrusher, zone1);
	}

	zone2 =  m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), isCrusher, goalCell->getZone());

	if (zone1 == zone2) {
		if (checkDestination(obj, goalCellNdx.x, goalCellNdx.y, destinationLayer, radius, center)) {
			return true;
		}
	}

	enum {MAX_CELLS_TO_TRY=400};
	Int limit = MAX_CELLS_TO_TRY; 
	Int i, j;
	i = goalCellNdx.x;
	j = goalCellNdx.y;

	Int delta=1;
	Int count;
	while (limit>0) {
		for (count = delta; count>0; count--) {
			i++;
			limit--;
			if (checkForPossible(isCrusher, zone1, center, locomotorSet, i,j, destinationLayer, dest, isObstacle)) {
				if (checkDestination(obj, i, j, destinationLayer, radius, center)) {
					return true;
				}
			}
		}
		for (count = delta; count>0; count--) {
			j++;
			limit--;
			if (checkForPossible(isCrusher, zone1, center, locomotorSet, i,j, destinationLayer, dest, isObstacle)) {
				if (checkDestination(obj, i, j, destinationLayer, radius, center)) {
					return true;
				}
			}
		}
		delta++;
		for (count = delta; count>0; count--) {
			i--;
			limit--;
			if (checkForPossible(isCrusher, zone1, center, locomotorSet, i,j, destinationLayer, dest, isObstacle)) {
				if (checkDestination(obj, i, j, destinationLayer, radius, center)) {
					return true;
				}
			}
		}
		for (count = delta; count>0; count--) {
			j--;
			limit--;
			if (checkForPossible(isCrusher, zone1, center, locomotorSet, i,j, destinationLayer, dest, isObstacle)) {
				if (checkDestination(obj, i, j, destinationLayer, radius, center)) {
					return true;
				}
			}
		}
		delta++;
	}
	return false;
}


/**
 * Queues an object to do a pathfind.
 * It will call the object's ai update->doPathfind() during processPathfindQueue().
 */
Bool Pathfinder::queueForPath(ObjectID id)
{
#if defined(_DEBUG) || defined(_INTERNAL)
	{
		Object *tmpObj = TheGameLogic->findObjectByID(id);
		if (tmpObj) {
			AIUpdateInterface *tmpAI = tmpObj->getAIUpdateInterface();
			if (tmpAI) {
				const Coord3D* pos = tmpAI->friend_getRequestedDestination();
				DEBUG_ASSERTLOG(pos->x != 0.0 && pos->y != 0.0, ("Queueing pathfind to (0, 0), usually a bug. (Unit Name: '%s', Type: '%s' \n", tmpObj->getName().str(), tmpObj->getTemplate()->getName().str()));
			}
		}
	}
#endif
	
	/* Check & see if we are already queued. */
	Int slot = m_queuePRHead;
	while (slot != m_queuePRTail) {
		if (m_queuedPathfindRequests[slot] == id) {
			return true;
		}
		slot++;
		if (slot >= PATHFIND_QUEUE_LEN) {
			slot = 0;
		}
	}

	// Tail is the first available slot.
	Int nextSlot = m_queuePRTail+1;
	if (nextSlot >= PATHFIND_QUEUE_LEN) {
		nextSlot = 0;
	}
	if (nextSlot==m_queuePRHead) {
		DEBUG_CRASH(("Ran out of pathfind queue slots."));
		return false;
	}
	m_queuedPathfindRequests[m_queuePRTail] = id;
	m_queuePRTail = nextSlot;
	return true;
}

#if defined _DEBUG || defined _INTERNAL
void Pathfinder::doDebugIcons(void) {
	const Int FRAMES_TO_SHOW_OBSTACLES = 100;
	extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
	// render AI debug information
	if (TheGlobalData->m_debugAI!=AI_DEBUG_CELLS && TheGlobalData->m_debugAI!=AI_DEBUG_TERRAIN) {
		return;
	}

		RGBColor color;
		color.red = color.green = color.blue = 0;	
		addIcon(NULL, 0, 0, color);	 // clear.
		Coord3D topLeftCorner;
		Bool showCells = TheGlobalData->m_debugAI==AI_DEBUG_CELLS;
		Int i;
		for (i=0; i<=LAYER_LAST; i++) {
			m_layers[i].doDebugIcons();
		}
		if (!showCells)	{
			frameToShowObstacles = TheGameLogic->getFrame()+FRAMES_TO_SHOW_OBSTACLES;
			//return;
		}	
		// show the pathfind grid
		for( int j=0; j<getExtent()->y; j++ )
		{
			topLeftCorner.y = (Real)j * PATHFIND_CELL_SIZE_F;

			for( int i=0; i<getExtent()->x; i++ )
			{
				topLeftCorner.x = (Real)i * PATHFIND_CELL_SIZE_F;
				
				color.red = color.green = color.blue = 0;	
				Bool empty = true;
				
				const PathfindCell *cell = TheAI->pathfinder()->getCell( LAYER_GROUND, i, j );
				if (cell)
				{
					switch (cell->getType())
					{
						case PathfindCell::CELL_CLIFF:
							color.red = 1;
							empty = false;
							break;
						case PathfindCell::CELL_IMPASSABLE:
							color.green = 1;
							empty = false;
							break;

						case PathfindCell::CELL_WATER:
							color.blue = 1;
							empty = false;
							break;

						case PathfindCell::CELL_RUBBLE:
							color.red = 1;
							color.green = 0.5;
							empty = false;
							break;

						case PathfindCell::CELL_OBSTACLE:
							color.red = color.green = 1;
							empty = false;
							break;
						default:
							if (cell->getPinched()) {
								color.blue = color.green = 0.7f;
								empty = false;
							}
							break;
					}
				}
				if (showCells) {
					empty = true;
					color.red = color.green = color.blue = 0;	
					if (empty && cell) {
						if (cell->getFlags()!=PathfindCell::NO_UNITS) {
							empty = false;
							if (cell->getFlags() == PathfindCell::UNIT_GOAL) {
								color.red = 1;
							}	else if (cell->getFlags() == PathfindCell::UNIT_PRESENT_FIXED) {
								color.green = color.blue = color.red = 1;
							}	else if (cell->getFlags() == PathfindCell::UNIT_PRESENT_MOVING) {
								color.green = 1;
							}	else {
								color.green = color.red = 1;
							}
						}
						if (cell->isAircraftGoal()) {
							empty = false;
							color.red = 0;
							color.green = color.blue = 1;
						}
					}
				}
				if (!empty) {
					Coord3D loc;
					loc.x = topLeftCorner.x + PATHFIND_CELL_SIZE_F/2.0f;
					loc.y = topLeftCorner.y + PATHFIND_CELL_SIZE_F/2.0f;
					loc.z = TheTerrainLogic->getGroundHeight(loc.x , loc.y);
					addIcon(&loc, PATHFIND_CELL_SIZE_F*0.8f, FRAMES_TO_SHOW_OBSTACLES-1, color);
				}
			}

	}
}
#endif


//-------------------------------------------------------------------------------------------------
/**
 * Create an aircraft path.  Just jogs around tall buildings marked with KINDOF_AIRCRAFT_PATH_AROUND.
 */
Path *Pathfinder::getAircraftPath( const Object *obj, const Coord3D *to )
{
	// for now, quick path objects don't pathfind, generally airborne units
	// build a trivial one-node path containing destination, then avoid buildings.
	

	Path *thePath = newInstance(Path);
	const AIUpdateInterface *ai = obj->getAI();
	ObjectID avoidObject = INVALID_ID;
	if (ai) {
		avoidObject = ai->getBuildingToNotPathAround();
	}

	// If it is an aircraft that circles (like raptors & migs) we need to adjust the destination
	// to one that doesn't clip buildings.
	Bool checkClips = false;
	if (ai && ai->getCurLocomotor()) {
		if (ai->getCurLocomotor()->getAppearance() == LOCO_WINGS) {
			checkClips = true;
		}
	}

	Real radius = 100;
	Coord3D adjDest = *to;
	if (checkClips) {
		circleClipsTallBuilding(obj->getPosition(), to, radius, avoidObject, &adjDest);
	}
	thePath->prependNode(&adjDest, LAYER_GROUND);
	Coord3D pos = *obj->getPosition();
	pos.z = to->z;
	thePath->prependNode( &pos, LAYER_GROUND );
	Int limit = 20;
	PathNode *curNode = thePath->getFirstNode();
	while (curNode && curNode->getNext()) {
		Coord3D newPos1, newPos2, newPos3;
		if (segmentIntersectsTallBuilding(curNode, curNode->getNext(), avoidObject, &newPos1, &newPos2, &newPos3)) {
			PathNode *newNode3 = newInstance(PathNode);
			newNode3->setPosition( &newPos3 );
			newNode3->setLayer(LAYER_GROUND);	
			curNode->append(newNode3);
			PathNode *newNode2 = newInstance(PathNode);
			newNode2->setPosition( &newPos2 );
			newNode2->setLayer(LAYER_GROUND);	
			curNode->append(newNode2);
			PathNode *newNode1 = newInstance(PathNode);
			newNode1->setPosition( &newPos1 );
			newNode1->setLayer(LAYER_GROUND);	
			curNode->append(newNode1);
			curNode = newNode2;
		}
		curNode = curNode->getNext();
		limit--;
		if (limit<0) break;
	}

	curNode = thePath->getFirstNode();
	while (curNode && curNode->getNext()) {
		curNode->setNextOptimized(curNode->getNext());
		curNode = curNode->getNext();
	}
	thePath->markOptimized();
	if (TheGlobalData->m_debugAI==AI_DEBUG_PATHS) {
		TheAI->pathfinder()->setDebugPath(thePath);
	}

	return thePath;
}


/** 
 * Process some path requests in the pathfind queue.
 */
//DECLARE_PERF_TIMER(processPathfindQueue)
void Pathfinder::processPathfindQueue(void)
{
	//USE_PERF_TIMER(processPathfindQueue)
	if (!m_isMapReady) {
		return;
	}
#ifdef DEBUG_QPF
#if defined _DEBUG || defined _INTERNAL
	Int startTimeMS = ::GetTickCount();
	__int64 startTime64;
	double timeToUpdate=0.0f;
	__int64 endTime64,freq64;
	QueryPerformanceFrequency((LARGE_INTEGER *)&freq64);
	QueryPerformanceCounter((LARGE_INTEGER *)&startTime64);
#endif
#endif

	if (m_zoneManager.needToCalculateZones()) {
		m_zoneManager.calculateZones(m_map, m_layers, m_extent);
		return;
	}

	// Get the current logical extent.
	Region3D terrainExtent;
	TheTerrainLogic->getExtent( &terrainExtent );
	IRegion2D bounds;
	bounds.lo.x = REAL_TO_INT_FLOOR(terrainExtent.lo.x / PATHFIND_CELL_SIZE_F);
	bounds.hi.x = REAL_TO_INT_FLOOR(terrainExtent.hi.x / PATHFIND_CELL_SIZE_F);
	bounds.lo.y = REAL_TO_INT_FLOOR(terrainExtent.lo.y / PATHFIND_CELL_SIZE_F);
	bounds.hi.y = REAL_TO_INT_FLOOR(terrainExtent.hi.y / PATHFIND_CELL_SIZE_F);
	bounds.hi.x--;
	bounds.hi.y--;
	m_logicalExtent = bounds;

	m_cumulativeCellsAllocated = 0;	// Number of pathfind cells examined.
	Int pathsFound = 0;
	while (m_cumulativeCellsAllocated < PATHFIND_CELLS_PER_FRAME && 
		m_queuePRTail!=m_queuePRHead) {
		Object *obj = TheGameLogic->findObjectByID(m_queuedPathfindRequests[m_queuePRHead]);
		m_queuedPathfindRequests[m_queuePRHead] = INVALID_ID;
		if (obj) {
			AIUpdateInterface *ai = obj->getAIUpdateInterface();
			if (ai) {
				ai->doPathfind(this);
				pathsFound++;
			}
		}
		m_queuePRHead = m_queuePRHead+1;
		if (m_queuePRHead >= PATHFIND_QUEUE_LEN) {
			m_queuePRHead = 0;
		}
	}
	if (pathsFound>0) {
#ifdef DEBUG_QPF
#if defined _DEBUG || defined _INTERNAL
		QueryPerformanceCounter((LARGE_INTEGER *)&endTime64);
		timeToUpdate = ((double)(endTime64-startTime64) / (double)(freq64));
		if (timeToUpdate>0.01f) 
		{
			DEBUG_LOG(("%d Pathfind queue: %d paths, %d cells", TheGameLogic->getFrame(), pathsFound, m_cumulativeCellsAllocated));
			DEBUG_LOG(("Time %f (%f)", timeToUpdate, (::GetTickCount()-startTimeMS)/1000.0f));
			DEBUG_LOG(("\n"));
		}
#endif
#endif
	}
#if defined _DEBUG || defined _INTERNAL
	doDebugIcons();
#endif

}


void Pathfinder::checkChangeLayers(PathfindCell *parentCell)
{
		ICoord2D newCellCoord;
		PathfindCell *newCell;
		if (parentCell->getConnectLayer() != LAYER_INVALID) {
			newCellCoord.x = parentCell->getXIndex();
			newCellCoord.y = parentCell->getYIndex();

			if (parentCell->getConnectLayer() == LAYER_GROUND) {
				newCell = getCell(LAYER_GROUND, newCellCoord.x, newCellCoord.y );
			}	else {
				newCell = getCell(parentCell->getConnectLayer(), newCellCoord.x, newCellCoord.y);
			}
			DEBUG_ASSERTCRASH(newCell, ("Couldn't find cell."));
			if (newCell) {
				Bool onList = false;
				if (newCell->hasInfo()) {
					if (newCell->getOpen() || newCell->getClosed())
					{
						// already on one of the lists 
						onList = true;
					}
				}
				if (!onList) {
					if (!newCell->allocateInfo(newCellCoord)) {
						// Out of cells for pathing...
						return;
					}
					// compute cost of path thus far
					// keep track of path we're building - point back to cell we moved here from
					newCell->setParentCell(parentCell) ;
					// store cost of this path
					newCell->setCostSoFar(parentCell->getCostSoFar()); // same as parent cost
					newCell->setTotalCost(parentCell->getTotalCost()) ;
					// insert newCell in open list such that open list is sorted, smallest total path cost first
					m_openList = newCell->putOnSortedOpenList( m_openList );

				}
			}
		}
}


struct ExamineCellsStruct
{
	Pathfinder					*thePathfinder;
	const LocomotorSet	*theLoco;
	Bool								centerInCell;
	Bool								isHuman;
	Int									radius;
	const Object				*obj;
	PathfindCell				*goalCell;
};

/*static*/ Int Pathfinder::examineCellsCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	ExamineCellsStruct* d = (ExamineCellsStruct*)userData;
	Bool isCrusher = d->obj ? d->obj->getCrusherLevel() > 0 : false;
	if (d->thePathfinder->m_isTunneling) return 1; // abort.
	if (from && to) {
			if (!d->thePathfinder->validMovementPosition( isCrusher, d->theLoco->getValidSurfaces(), to, from )) {
				return 1;
			}
			if ( (to->getLayer() == LAYER_GROUND) && !d->thePathfinder->m_zoneManager.isPassable(to_x, to_y) ) {
				return 1;
			}
			Bool onList = false;
			if (to->hasInfo()) {
				if (to->getOpen() || to->getClosed())
				{
					// already on one of the lists 
					onList = true;
				}
			}
			if (to->getPinched()) {
				return 1; // abort.
			}
			if (d->isHuman) {
				// check if new cell is in logical map.	(computer can move off logical map)
				if (to_x < d->thePathfinder->m_logicalExtent.lo.x) return 1; // abort
				if (to_y < d->thePathfinder->m_logicalExtent.lo.y) return 1; // abort 
				if (to_x > d->thePathfinder->m_logicalExtent.hi.x) return 1; // abort 
				if (to_y > d->thePathfinder->m_logicalExtent.hi.y) return 1; // abort 
			}
			TCheckMovementInfo info;
			info.cell.x = to_x;
			info.cell.y = to_y;
			info.layer = from->getLayer();
			info.centerInCell = d->centerInCell;
			info.radius = d->radius;
			info.considerTransient = false;
			info.acceptableSurfaces = d->theLoco->getValidSurfaces();
			if (!d->thePathfinder->checkForMovement(d->obj, info) || info.enemyFixed) {
				return 1; //abort.
			}	
			if (info.enemyFixed) {
				return 1; //abort.
			}
			ICoord2D newCellCoord;
			newCellCoord.x = to_x;
			newCellCoord.y = to_y;

			UnsignedInt newCostSoFar = from->getCostSoFar( ) + 0.5f*COST_ORTHOGONAL;
			if (to->getType() == PathfindCell::CELL_CLIFF ) {
				return 1;
			}
			if (info.allyFixedCount) {
				return 1;
			} else if (info.enemyFixed) {
				return 1;
			}

			if (!to->allocateInfo(newCellCoord)) {
				// Out of cells for pathing...
 				return 1;
			}								
			to->setBlockedByAlly(false);
			Int costRemaining = 0;
			costRemaining = to->costToGoal( d->goalCell );
			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			if (onList)
			{
				// already on one of the lists - if existing costSoFar is less, 
				// the new cell is on a longer path, so skip it
				if (to->getCostSoFar() <= newCostSoFar)
					return 0; // keep going.
			}
			to->setCostSoFar(newCostSoFar);
			// keep track of path we're building - point back to cell we moved here from
			to->setParentCell(from) ;
			to->setTotalCost(to->getCostSoFar() + costRemaining) ;

			//DEBUG_LOG(("Cell (%d,%d), Parent cost %d, newCostSoFar %d, cost rem %d, tot %d\n", 
			//	to->getXIndex(), to->getYIndex(), 
			//	to->costSoFar(from), newCostSoFar, costRemaining, to->getCostSoFar() + costRemaining));

			// if to was on closed list, remove it from the list
			if (to->getClosed())
				d->thePathfinder->m_closedList = to->removeFromClosedList( d->thePathfinder->m_closedList );

			// if the to was already on the open list, remove it so it can be re-inserted in order
			if (to->getOpen())
				d->thePathfinder->m_openList = to->removeFromOpenList( d->thePathfinder->m_openList );

			// insert to in open list such that open list is sorted, smallest total path cost first
			d->thePathfinder->m_openList = to->putOnSortedOpenList( d->thePathfinder->m_openList );
	}

	return 0;	// keep going
}




Int Pathfinder::examineNeighboringCells(PathfindCell *parentCell, PathfindCell *goalCell, const LocomotorSet& locomotorSet, 
																				 Bool isHuman, Bool centerInCell, Int radius, const ICoord2D &startCellNdx,
																				 const Object *obj, Int attackDistance)
{
		Bool canPathThroughUnits = false;
		if (obj && obj->getAIUpdateInterface()) {
			canPathThroughUnits = obj->getAIUpdateInterface()->canPathThroughUnits();
		}
		Bool isCrusher = obj ? obj->getCrusherLevel() > 0 : false;
		if (attackDistance==NO_ATTACK && !m_isTunneling && !locomotorSet.isDownhillOnly() && goalCell) {
			ExamineCellsStruct info;
			info.thePathfinder = this;
			info.theLoco = &locomotorSet;
			info.centerInCell = centerInCell;
			info.radius = radius;
			info.obj = obj;
			info.isHuman = isHuman;
			info.goalCell = goalCell;
			ICoord2D start, end;
			start.x = parentCell->getXIndex();
			start.y = parentCell->getYIndex();
			end.x = goalCell->getXIndex();
			end.y = goalCell->getYIndex();
			iterateCellsAlongLine(start, end, parentCell->getLayer(), examineCellsCallback, &info);
		}

		Int cellCount = 0;
		// expand search to neighboring orthogonal cells
		static ICoord2D delta[] = 
		{ 
			{ 1, 0 }, { 0, 1 }, { -1, 0 }, { 0, -1 }, 
			{ 1, 1 }, { -1, 1 }, { -1, -1 }, { 1, -1 } 
		};
		const Int numNeighbors = 8;
		const Int firstDiagonal = 4;
		ICoord2D newCellCoord;
		PathfindCell *newCell;
		const Int adjacent[5] = {0, 1, 2, 3, 0};
		Bool neighborFlags[8] = {false, false, false, false, false, false, false};

		UnsignedInt newCostSoFar;



		for( int i=0; i<numNeighbors; i++ )
		{
			neighborFlags[i] = false;
			// determine neighbor cell to try
			newCellCoord.x = parentCell->getXIndex() + delta[i].x;
			newCellCoord.y = parentCell->getYIndex() + delta[i].y;

			// get the neighboring cell
			newCell = getCell(parentCell->getLayer(), newCellCoord.x, newCellCoord.y );

			// check if cell is on the map
			if (newCell == NULL)
				continue;

			Bool notZonePassable = false;
			if ((newCell->getLayer()==LAYER_GROUND) && !m_zoneManager.isPassable(newCellCoord.x, newCellCoord.y)) {
				notZonePassable = true;
			}
			if (isHuman) {
				// check if new cell is in logical map.	(computer can move off logical map)
				if (newCellCoord.x < m_logicalExtent.lo.x) continue;
				if (newCellCoord.y < m_logicalExtent.lo.y) continue; 
				if (newCellCoord.x > m_logicalExtent.hi.x) continue; 
				if (newCellCoord.y > m_logicalExtent.hi.y) continue; 
			}

			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			Bool onList = false;
			if (newCell->hasInfo()) {
				if (newCell->getOpen() || newCell->getClosed())
				{
					// already on one of the lists 
					onList = true;
				}
			}
			if (onList) {
				// we have already examined this one, so continue.
				continue;
			}
			if (i>=firstDiagonal) {
				// make sure one of the adjacent sides is open.
				if (!neighborFlags[adjacent[i-4]] && !neighborFlags[adjacent[i-3]]) {
					continue;
				}
			}

			// do the gravity check here
			if ( locomotorSet.isDownhillOnly() )
			{
				Coord3D fromPos;
				fromPos.x = parentCell->getXIndex() * PATHFIND_CELL_SIZE_F ;
				fromPos.y = parentCell->getYIndex() * PATHFIND_CELL_SIZE_F ;
				fromPos.z = TheTerrainLogic->getGroundHeight(fromPos.x , fromPos.y);

				Coord3D toPos;
				toPos.x = newCellCoord.x * PATHFIND_CELL_SIZE_F ;
				toPos.y = newCellCoord.y * PATHFIND_CELL_SIZE_F ;
				toPos.z = TheTerrainLogic->getGroundHeight(toPos.x , toPos.y);

				if ( fromPos.z < toPos.z )
					continue;
			}



			Bool movementValid = true;
			Bool dozerHack = false;
			if (validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), newCell, parentCell )) {
			}	else {
				movementValid = false;
				if (obj->isKindOf(KINDOF_DOZER)) {
					if (newCell->getType()==PathfindCell::CELL_OBSTACLE) {
						Object *obstacle = TheGameLogic->findObjectByID(newCell->getObstacleID());
						if (obstacle && !(obj->getRelationship(obstacle)==ENEMIES)) {
							movementValid = true;
							dozerHack = true;
						}
					}
				}
				if (!movementValid && !m_isTunneling) {
					continue;
				}
			}	
			if (!dozerHack) 
				neighborFlags[i] = true;

			TCheckMovementInfo info;
			info.cell = newCellCoord;
			info.layer = parentCell->getLayer();
			info.centerInCell = centerInCell;
			info.radius = radius;
			info.considerTransient = false;
			info.acceptableSurfaces = locomotorSet.getValidSurfaces();
			Int dx = newCellCoord.x-startCellNdx.x;
			Int dy = newCellCoord.y-startCellNdx.y;
			if (dx<0) dx = -dx;
			if (dy<0) dy = -dy;
			if (dx>1+radius) info.considerTransient = false;
			if (dy>1+radius) info.considerTransient = false;
			if (!checkForMovement(obj, info) || info.enemyFixed) {
				if (!m_isTunneling) {
					continue;
				}
				movementValid = false;
			}	
			if (movementValid && !newCell->getPinched()) {
				//Note to self - only turn off tunneling after check for movement.jba. 
				m_isTunneling = false;
			}
			if (!newCell->hasInfo()) {
				if (!newCell->allocateInfo(newCellCoord)) {
					// Out of cells for pathing...
 					return cellCount;
				}								
				cellCount++;
			}

			newCostSoFar = newCell->costSoFar( parentCell );
			if (info.allyMoving && dx<10 && dy<10) {
				newCostSoFar += 3*COST_DIAGONAL;
			}
			if (newCell->getType() == PathfindCell::CELL_CLIFF && !newCell->getPinched() ) {
				Coord3D fromPos;
				fromPos.x = parentCell->getXIndex() * PATHFIND_CELL_SIZE_F ;
				fromPos.y = parentCell->getYIndex() * PATHFIND_CELL_SIZE_F ;
				fromPos.z = TheTerrainLogic->getGroundHeight(fromPos.x , fromPos.y);

				Coord3D toPos;
				toPos.x = newCellCoord.x * PATHFIND_CELL_SIZE_F ;
				toPos.y = newCellCoord.y * PATHFIND_CELL_SIZE_F ;
				toPos.z = TheTerrainLogic->getGroundHeight(toPos.x , toPos.y);

				if ( fabs(fromPos.z - toPos.z)<PATHFIND_CELL_SIZE_F) {
					newCostSoFar += 7*COST_DIAGONAL;
				}
			} else if (newCell->getPinched()) {
				newCostSoFar += COST_ORTHOGONAL;
			}
			newCell->setBlockedByAlly(false);
			if (info.allyFixedCount) {
				if (canPathThroughUnits) {
					newCostSoFar += 3*COST_DIAGONAL*info.allyFixedCount;
				}	else {
					newCell->setBlockedByAlly(true);
					newCostSoFar += 3*COST_DIAGONAL*info.allyFixedCount;
				}
			} 
			Int costRemaining = 0;
			if (goalCell) {
				if (attackDistance == 0)  {
					costRemaining = newCell->costToGoal( goalCell );
				}	else {
					dx = newCellCoord.x - goalCell->getXIndex();
					dy = newCellCoord.y - goalCell->getYIndex();
					costRemaining = COST_ORTHOGONAL*sqrt(dx*dx + dy*dy);
					costRemaining -= attackDistance/2;
					if (costRemaining<0) costRemaining=0;
					if (info.allyGoal) {
						if (obj->isKindOf(KINDOF_VEHICLE)) {
							newCostSoFar += 3*COST_ORTHOGONAL; 
						}	else {
							// Infantry can pass through infantry.
							newCostSoFar += COST_ORTHOGONAL;
						}
					}
				}
			}
			if (notZonePassable) {
				newCostSoFar += 100*COST_ORTHOGONAL;
			}
			if (newCell->getType()==PathfindCell::CELL_OBSTACLE) {
				newCostSoFar += 100*COST_ORTHOGONAL;
			}
			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			if (onList)
			{
				// already on one of the lists - if existing costSoFar is less, 
				// the new cell is on a longer path, so skip it
				if (newCell->getCostSoFar() <= newCostSoFar)
					continue;
			}
			if (m_isTunneling) {
				if (!validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), newCell, parentCell )) {
					newCostSoFar += 10*COST_ORTHOGONAL;
				}
			}
			newCell->setCostSoFar(newCostSoFar);
			// keep track of path we're building - point back to cell we moved here from
			newCell->setParentCell(parentCell) ;
			if (m_isTunneling) {
				costRemaining = 0; // find the closest valid cell.
			}
			newCell->setTotalCost(newCell->getCostSoFar() + costRemaining) ;

			//DEBUG_LOG(("Cell (%d,%d), Parent cost %d, newCostSoFar %d, cost rem %d, tot %d\n", 
			//	newCell->getXIndex(), newCell->getYIndex(), 
			//	newCell->costSoFar(parentCell), newCostSoFar, costRemaining, newCell->getCostSoFar() + costRemaining));

			// if newCell was on closed list, remove it from the list
			if (newCell->getClosed())
				m_closedList = newCell->removeFromClosedList( m_closedList );

			// if the newCell was already on the open list, remove it so it can be re-inserted in order
			if (newCell->getOpen())
				m_openList = newCell->removeFromOpenList( m_openList );

			// insert newCell in open list such that open list is sorted, smallest total path cost first
			m_openList = newCell->putOnSortedOpenList( m_openList );
		}
	return cellCount;
}


/**
 * Find a short, valid path between given locations.
 * Uses A* algorithm.
 */
Path *Pathfinder::findPath( Object *obj, const LocomotorSet& locomotorSet, const Coord3D *from, 
													 const Coord3D *rawTo)
{
	if (!quickDoesPathExist(locomotorSet, from, rawTo)) {
		return NULL;
	}
	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}

	m_zoneManager.clearPassableFlags();
	Path *hPat = findHierarchicalPath(isHuman, locomotorSet, from, rawTo, false);
	if (hPat) {
		hPat->deleteInstance();
	}	else {
		m_zoneManager.setAllPassable();
	}

	Path *pat = internalFindPath(obj, locomotorSet, from, rawTo);
	if (pat!=NULL) {
		return pat;
	}

/* hierarchical build path code.
	if (pat) {

		Path *path = newInstance(Path);
		PathNode *prior = NULL;
		for (PathNode *node = pat->getLastNode(); node; node=node->getPrevious()) {
			Bool unobstructed = true;
			if (prior!=NULL) {
				unobstructed = isLinePassable( obj, locomotorSet.getValidSurfaces(), 
				prior->getLayer(), *prior->getPosition(), *node->getPosition(), false, true);
			}
			if (unobstructed) {
				path->prependNode( node->getPosition(), node->getLayer() );
				path->getFirstNode()->setCanOptimize(node->getCanOptimize());	
				path->getFirstNode()->setNextOptimized(path->getFirstNode()->getNext());
			} else {
				Path *linkPath = findClosestPath(obj, locomotorSet, node->getPosition(), 
					prior->getPosition(), false, 0, true);
				if (linkPath==NULL) {
					DEBUG_LOG(("Couldn't find path - unexpected. jba.\n"));
					continue;
				}
				PathNode *linkNode = linkPath->getLastNode();
				if (linkNode==NULL) {
					DEBUG_LOG(("Empty path - unexpected. jba.\n"));
					continue;
				}
				for (linkNode=linkNode->getPrevious(); linkNode; linkNode=linkNode->getPrevious()) {
					path->prependNode( linkNode->getPosition(), linkNode->getLayer() );
					path->getFirstNode()->setCanOptimize(linkNode->getCanOptimize());
					path->getFirstNode()->setNextOptimized(path->getFirstNode()->getNext());
				}
				linkPath->deleteInstance();
			}
			prior = node;
		}
		pat->deleteInstance();
		path->optimize(obj, locomotorSet.getValidSurfaces(), false);
		if (TheGlobalData->m_debugAI) {
			setDebugPath(path);
		}
		return path;
	}
*/
	return NULL; 
}
/**
 * Find a short, valid path between given locations.
 * Uses A* algorithm.
 */
Path *Pathfinder::internalFindPath( Object *obj, const LocomotorSet& locomotorSet, const Coord3D *from, 
													 const Coord3D *rawTo)
{
	//CRCDEBUG_LOG(("Pathfinder::findPath()\n"));
#ifdef INTENSE_DEBUG
	DEBUG_LOG(("internal find path...\n"));
#endif

#if defined _DEBUG || defined _INTERNAL
	Int startTimeMS = ::GetTickCount();
#endif
	Bool centerInCell = true;
	Int radius = 0;
	if (obj) {
		getRadiusAndCenter(obj, radius, centerInCell);
	}
	
	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}

	if (rawTo->x == 0.0f && rawTo->y == 0.0f) {
		DEBUG_LOG(("Attempting pathfind to 0,0, generally a bug.\n"));
		return NULL;
	}
	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));
	if (m_isMapReady == false) {
		return NULL;
	}

	Coord3D adjustTo = *rawTo;
	Coord3D *to = &adjustTo;
	Coord3D clipFrom = *from;
	clip(&clipFrom, &adjustTo);

	if (!centerInCell) {
		adjustTo.x += PATHFIND_CELL_SIZE_F/2;
		adjustTo.y += PATHFIND_CELL_SIZE_F/2;
	}

	m_isTunneling = false;

	PathfindLayerEnum destinationLayer = TheTerrainLogic->getLayerForDestination(to);
	// determine goal cell
	PathfindCell *goalCell = getCell( destinationLayer, to );
	if (goalCell == NULL) {
		return NULL;
	}
	
	ICoord2D cell;
	worldToCell( to, &cell );

	if (!checkDestination(obj, cell.x, cell.y, destinationLayer, radius, centerInCell)) {
		return false;
	}
	// determine start cell
	ICoord2D startCellNdx;
	worldToCell(&clipFrom, &startCellNdx);
	PathfindLayerEnum layer = LAYER_GROUND;
	if (obj) {
		layer = obj->getLayer();
	}
	PathfindCell *parentCell = getClippedCell( layer,&clipFrom );
	if (parentCell == NULL) {
		return NULL;
	}

	ICoord2D pos2d;
	worldToCell(to, &pos2d);
	if (!goalCell->allocateInfo(pos2d)) {
		return NULL;
	}
	if (parentCell!=goalCell) {
		worldToCell(&clipFrom, &pos2d);
		if (!parentCell->allocateInfo(pos2d)) {
			goalCell->releaseInfo();
			return NULL;
		}
	}
	//
	// Determine if this pathfind is "tunneling" or not.
	// A tunneling pathfind starts from within an obstacle, and is allowed
	// to ignore obstacle cells until it reaches a cell that is no longer
	// classified as an obstacle.  At that point, the pathfind behaves normally.
	//
	if (parentCell->getType() == PathfindCell::CELL_OBSTACLE)	{
		m_isTunneling = true;
	}
	else {
		m_isTunneling = false;
	}

	Int zone1, zone2;
	Bool isCrusher = obj ? obj->getCrusherLevel() > 0 : false;
	zone1 = m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), isCrusher, parentCell->getZone()); 
	zone2 =  m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), isCrusher, goalCell->getZone());

	if (layer==LAYER_WALL && zone1 == 0) {
		return NULL;
	}

	if (destinationLayer==LAYER_WALL && zone2 == 0) {
		return NULL;
	}

	if (goalCell->isObstaclePresent(m_ignoreObstacleID) || m_isTunneling) {
		// Use terrain zones instead of building zones, since we are moving into or out of a building.
		zone2 = m_zoneManager.getEffectiveTerrainZone(zone2);
		zone2 =  m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), isCrusher, zone2);
		zone1 = m_zoneManager.getEffectiveTerrainZone(zone1);
		zone1 = m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), isCrusher, zone1); 
	}																																 

	//DEBUG_LOG(("Zones %d to %d\n", zone1, zone2));

	if ( zone1 != zone2) {
		//DEBUG_LOG(("Intense Debug Info - Pathfind Zone screen failed-cannot reach desired location.\n"));
		goalCell->releaseInfo();
		parentCell->releaseInfo();
		return NULL;
	}

	// sanity check - if destination is invalid, can't path there
	if (validMovementPosition( isCrusher, destinationLayer, locomotorSet, to ) == false)	{
		m_isTunneling = false;
		goalCell->releaseInfo();
		parentCell->releaseInfo();
		return NULL;
	}

	// sanity check - if source is invalid, we have to cheat
	if (validMovementPosition( isCrusher, layer, locomotorSet, from ) == false)	{
		// somehow we got to an impassable location.
		m_isTunneling = true;
	}

	parentCell->startPathfind(goalCell);

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;

	Int cellCount = 0;

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//
	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		if (parentCell == goalCell)
		{
			// success - found a path to the goal
			Bool show = TheGlobalData->m_debugAI==AI_DEBUG_PATHS;
#ifdef INTENSE_DEBUG
			DEBUG_LOG(("internal find path SUCCESS...\n"));
			Int count = 0;
			if (cellCount>1000 && obj) {
				show = true;
				DEBUG_LOG(("cells %d obj %s %x from (%f,%f) to(%f, %f)\n", count, obj->getTemplate()->getName().str(), obj, from->x, from->y, to->x, to->y));
#ifdef STATE_MACHINE_DEBUG
				if( obj->getAIUpdateInterface() )
				{
					DEBUG_LOG(("State %s\n",  obj->getAIUpdateInterface()->getCurrentStateName().str()));
				}
#endif
				TheScriptEngine->AppendDebugMessage("Big path", false);
			}
#endif
			if (show)
				debugShowSearch(true);

			m_isTunneling = false;
			// construct and return path
			Path *path =  buildActualPath( obj, locomotorSet.getValidSurfaces(), from, goalCell, centerInCell, false );
			parentCell->releaseInfo();
			cleanOpenAndClosedLists();
			return path;
		}	

		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );

		// Check to see if we can change layers in this cell.
		checkChangeLayers(parentCell);

		cellCount += examineNeighboringCells(parentCell, goalCell, locomotorSet, isHuman, centerInCell, radius, startCellNdx, obj, NO_ATTACK);

	}

	// failure - goal cannot be reached
#if defined _DEBUG || defined _INTERNAL
#ifdef INTENSE_DEBUG
	DEBUG_LOG(("internal find path FAILURE...\n"));
#endif
	if (TheGlobalData->m_debugAI == AI_DEBUG_PATHS)
	{
		extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 		RGBColor color;
		color.blue = 0;
		color.red = color.green = 1;
		addIcon(NULL, 0, 0, color);
		debugShowSearch(false);
		Coord3D pos;
		pos = *from;
		pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
		addIcon(&pos, 3*PATHFIND_CELL_SIZE_F, 600, color);
		pos = *to;
		pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
		addIcon(&pos, 3*PATHFIND_CELL_SIZE_F, 600, color);	
		Real dx, dy;
		dx = from->x - to->x;
		dy = from->y - to->y;

		Int count = sqrt(dx*dx+dy*dy)/(PATHFIND_CELL_SIZE_F/2);
		if (count<2) count = 2;
		Int i;
		color.green = 0;
		for (i=1; i<count; i++) {
			pos.x = from->x + (to->x-from->x)*i/count;
			pos.y = from->y + (to->y-from->y)*i/count;
			pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
			addIcon(&pos, PATHFIND_CELL_SIZE_F/2, 60, color);

		}
	}	

	if (obj) {
		Bool valid;
		valid = validMovementPosition( isCrusher, obj->getLayer(), locomotorSet, to ) ;

		DEBUG_LOG(("%d ", TheGameLogic->getFrame()));
		DEBUG_LOG(("Pathfind failed from (%f,%f) to (%f,%f), OV %d\n", from->x, from->y, to->x, to->y, valid));
		DEBUG_LOG(("Unit '%s', time %f, cells %d\n", obj->getTemplate()->getName().str(), (::GetTickCount()-startTimeMS)/1000.0f,cellCount));
#ifdef DUMP_PERF_STATS
		TheGameLogic->incrementOverallFailedPathfinds();
#endif
#ifdef STATE_MACHINE_DEBUG
		if( obj->getAIUpdateInterface() )
		{
			DEBUG_LOG(("state %s\n", obj->getAIUpdateInterface()->getCurrentStateName().str()));
		}
#endif
	}
#endif
	m_isTunneling = false;
	goalCell->releaseInfo();
	cleanOpenAndClosedLists();
	return NULL;
}

/**
 * Checks to see if there is enough path width at this cell for ground
 * movement.  Returns the width available.
 */
Int Pathfinder::clearCellForDiameter(Bool crusher, Int cellX, Int cellY, PathfindLayerEnum layer, Int pathDiameter)	  
{
	Int radius = pathDiameter/2;
	Int numCellsAbove = radius;
	if (radius==0) numCellsAbove++;
	Int i, j;
	Bool clear = true;
	Bool cutCorners = false;
	if (radius>1) {
		cutCorners = true;
		// We remove the outside corner cells from the check.
	}
	for (i=cellX-radius; i<cellX+numCellsAbove; i++) {
		Bool xMinOrMax = (i==cellX-radius) || (i==cellX+numCellsAbove-1);
		for (j=cellY-radius; j<cellY+numCellsAbove; j++) {
			Bool yMinOrMax = (j==cellY-radius) || (j==cellY+numCellsAbove-1);
			if (xMinOrMax && yMinOrMax && cutCorners) {
				continue; // this is an outside corner cell, and we are cutting corners. jba. :)
			}
			PathfindCell	*cell = getCell(layer, i, j);
			if (cell) {
				if (cell->getType() != PathfindCell::CELL_CLEAR) {
					if (cell->getType() == PathfindCell::CELL_OBSTACLE) {
						if (cell->isObstacleFence()) {
							if (!crusher) {
								clear = false;
							}
						} else {
							clear = false;
						}
					} else {
						clear = false;
					}
				}
				if (cell->getFlags() == PathfindCell::UNIT_PRESENT_FIXED && pathDiameter>=2) {
					Object *obj = TheGameLogic->findObjectByID(cell->getPosUnit());
					if (obj) {
						if (crusher) {
							if (obj->getCrushableLevel()>1) {
								clear = false;
							}
						} else {
							if (obj->getCrushableLevel()>0) {
								clear = false;
							}
						}
					}
				}
			} else {
				return false; // off the map.
			}
			if (!clear) break;
		}
	}
	if (clear) {
		if (radius==0) return 1;
		return 2*radius;
	}
	if (pathDiameter < 2) return 0;
	return clearCellForDiameter(crusher, cellX, cellY, layer, pathDiameter-2);
}

/**
 * Work backwards from goal cell to construct final path.
 */
Path *Pathfinder::buildGroundPath(Bool isCrusher, const Coord3D *fromPos, PathfindCell *goalCell, Bool center, Int pathDiameter )
{
	DEBUG_ASSERTCRASH( goalCell, ("Pathfinder::buildActualPath: goalCell == NULL") );

	Path *path = newInstance(Path);

	prependCells(path, fromPos, goalCell, center);

	// cleanup the path by checking line of sight
	path->optimizeGroundPath( isCrusher, pathDiameter );


#if defined _DEBUG || defined _INTERNAL
	if (TheGlobalData->m_debugAI==AI_DEBUG_GROUND_PATHS)
	{
		extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 		RGBColor color;
		color.blue = 0;
		color.red = color.green = 1;
		Coord3D pos;
		for( PathNode *node = path->getFirstNode(); node; node = node->getNext() )
		{

			// create objects to show path - they decay

			pos = *node->getPosition();
			color.red = color.green = 1;
			if (node->getLayer() != LAYER_GROUND) {
				color.red = 0;
			}
			addIcon(&pos, PATHFIND_CELL_SIZE_F*.25f, 200, color);
		}

		// show optimized path
		for( node = path->getFirstNode(); node; node = node->getNextOptimized() )
		{
			pos = *node->getPosition();
			addIcon(&pos, PATHFIND_CELL_SIZE_F*.8f, 200, color);
		}
		setDebugPath(path);
	}
#endif
	return path;
}			 

/**
 * Work backwards from goal cell to construct final path.
 */
Path *Pathfinder::buildHierachicalPath( const Coord3D *fromPos, PathfindCell *goalCell )
{
	DEBUG_ASSERTCRASH( goalCell, ("Pathfinder::buildHierachicalPath: goalCell == NULL") );

	Path *path = newInstance(Path);

	prependCells(path, fromPos, goalCell, true);

#if defined _DEBUG || defined _INTERNAL
	if (TheGlobalData->m_debugAI==AI_DEBUG_PATHS)
	{
		extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 		RGBColor color;
		color.blue = 0;
		color.red = color.green = 1;
		Coord3D pos;
		Int i;
		for (i=0; i<3; i++)
		for( PathNode *node = path->getFirstNode(); node; node = node->getNext() )
		{

			// create objects to show path - they decay

			pos = *node->getPosition();
			color.red = 1;
			color.green = 0.4f;
			if (node->getLayer() != LAYER_GROUND) {
				color.red = 0;
			}
			addIcon(&pos, PATHFIND_CELL_SIZE_F, 200, color);
		}
		setDebugPath(path);
	}
#endif
	return path;
}			 


struct MADStruct
{
	Pathfinder					*thePathfinder;
	Object							*obj;
	ObjectID						ignoreID;
};

/*static*/ Int Pathfinder::moveAlliesDestinationCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	MADStruct* d = (MADStruct*)userData;
	if (to) {
		if (to->getPosUnit()==INVALID_ID) {
			return 0;
		}
		if (to->getPosUnit()==d->obj->getID()) { 
			return 0;	// It's us.
		}
		if (to->getPosUnit()==d->ignoreID) { 
			return 0;	 // It's the one we are ignoring.
		}
		Object *otherObj = TheGameLogic->findObjectByID(to->getPosUnit());
		if (otherObj==NULL) return 0;
		if (d->obj->getRelationship(otherObj)!=ALLIES) {
			return 0;  // Only move allies.
		}
		if (otherObj && otherObj->getAI() && !otherObj->getAI()->isMoving()) {
			//DEBUG_LOG(("Moving ally\n"));
			otherObj->getAI()->aiMoveAwayFromUnit(d->obj, CMD_FROM_AI);
		}
	}

	return 0;	// keep going
}

void Pathfinder::moveAlliesAwayFromDestination(Object *obj,const Coord3D& destination)
{
	MADStruct info;
	info.obj = obj;
	info.ignoreID = obj->getAI()->getIgnoredObstacleID();
	info.thePathfinder = this;
	PathfindLayerEnum layer = obj->getLayer();
	if (layer==LAYER_GROUND) {
		layer = TheTerrainLogic->getLayerForDestination(&destination);
	}
	iterateCellsAlongLine(*obj->getPosition(), destination, layer, moveAlliesDestinationCallback, &info);

}


struct GroundCellsStruct
{
	Pathfinder					*thePathfinder;
	Bool								centerInCell;
	Int									pathDiameter;
	PathfindCell				*goalCell;
	Bool								crusher;
};

/*static*/ Int Pathfinder::groundCellsCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	GroundCellsStruct* d = (GroundCellsStruct*)userData;
	if (from && to) {
			if (to->hasInfo()) {
				if (to->getOpen() || to->getClosed())
				{
					// already on one of the lists 
					return 1; // abort.
				}
			}
			// See how wide the cell is.
			Int clearDiameter = d->thePathfinder->clearCellForDiameter(d->crusher, to_x, to_y, to->getLayer(), d->pathDiameter); 
			if (clearDiameter != d->pathDiameter) {
				return 1;
			}
			ICoord2D newCellCoord;
			newCellCoord.x = to_x;
			newCellCoord.y = to_y;
			if (!to->allocateInfo(newCellCoord)) {
				// Out of cells for pathing...
 				return 1;
			}								

			UnsignedInt newCostSoFar = from->getCostSoFar( ) + 0.5f*COST_ORTHOGONAL;
			to->setBlockedByAlly(false);

			Int costRemaining = 0;
			costRemaining = to->costToGoal( d->goalCell );
			to->setCostSoFar(newCostSoFar);
			// keep track of path we're building - point back to cell we moved here from
			to->setParentCell(from) ;
			to->setTotalCost(to->getCostSoFar() + costRemaining) ;

			// insert to in open list such that open list is sorted, smallest total path cost first
			d->thePathfinder->m_openList = to->putOnSortedOpenList( d->thePathfinder->m_openList );
	}

	return 0;	// keep going
}

/**
 * Find a short, valid path between given locations.
 * Uses A* algorithm.
 */
Path *Pathfinder::findGroundPath( const Coord3D *from, 
													 const Coord3D *rawTo, Int pathDiameter, Bool crusher)
{
	//CRCDEBUG_LOG(("Pathfinder::findGroundPath()\n"));
#if defined _DEBUG || defined _INTERNAL
	Int startTimeMS = ::GetTickCount();
#endif
#ifdef INTENSE_DEBUG
	DEBUG_LOG(("Find ground path..."));
#endif	
	Bool centerInCell = false;
	
	m_zoneManager.clearPassableFlags();
	Bool isHuman = true;

	Path *hPat = internal_findHierarchicalPath(isHuman, LOCOMOTORSURFACE_GROUND, from, rawTo, false, false);
	if (hPat) {
		hPat->deleteInstance();
	}	else {
		m_zoneManager.setAllPassable();
	}

	if (rawTo->x == 0.0f && rawTo->y == 0.0f) {
		DEBUG_LOG(("Attempting pathfind to 0,0, generally a bug.\n"));
		return NULL;
	}
	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));
	if (m_isMapReady == false) {
		return NULL;
	}

	Coord3D adjustTo = *rawTo;
	Coord3D *to = &adjustTo;
	Coord3D clipFrom = *from;
	clip(&clipFrom, &adjustTo);

	m_isTunneling = false;

	PathfindLayerEnum destinationLayer = TheTerrainLogic->getLayerForDestination(to);
	
	ICoord2D cell;
	worldToCell( to, &cell );

	if (pathDiameter!=clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)) {
		Int offset=1;
		ICoord2D newCell;
		const Int MAX_OFFSET = 8;
		while (offset<MAX_OFFSET) {
			newCell = cell;
			cell.x += offset;
			if (clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)==pathDiameter) break;
			cell.y += offset;
			if (clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)==pathDiameter) break;
			cell.x -= offset;
			if (clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)==pathDiameter) break;
			cell.x -= offset;
			if (clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)==pathDiameter) break;
			cell.y -= offset;
			if (clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)==pathDiameter) break;
			cell.y -= offset;
			if (clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)==pathDiameter) break;
			cell.x += offset;
			if (clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)==pathDiameter) break;
			cell.x += offset;
			if (clearCellForDiameter(crusher, cell.x, cell.y, destinationLayer, pathDiameter)==pathDiameter) break;
			offset++;
			cell = newCell;
		}
		if (offset >= MAX_OFFSET) {
			return NULL;
		}
	}

	// determine goal cell
	PathfindCell *goalCell = getCell( destinationLayer, cell.x, cell.y );
	if (goalCell == NULL) {
		return NULL;
	}
	if (!goalCell->allocateInfo(cell)) {
		return NULL;
	}

	// determine start cell
	ICoord2D startCellNdx;
	PathfindLayerEnum layer = TheTerrainLogic->getLayerForDestination(from);
	PathfindCell *parentCell = getClippedCell( layer,&clipFrom );
	if (parentCell == NULL) {
		return NULL;
	}
	if (parentCell!=goalCell) {
		worldToCell(&clipFrom, &startCellNdx);
		if (!parentCell->allocateInfo(startCellNdx)) {
			goalCell->releaseInfo();
			return NULL;
		}
	}


	Int zone1, zone2;
	// m_isCrusher = false;
	zone1 = m_zoneManager.getEffectiveZone(LOCOMOTORSURFACE_GROUND, false, parentCell->getZone()); 
	zone2 =  m_zoneManager.getEffectiveZone(LOCOMOTORSURFACE_GROUND, false, goalCell->getZone());

	//DEBUG_LOG(("Zones %d to %d\n", zone1, zone2));

	if ( zone1 != zone2) {
		goalCell->releaseInfo();
		parentCell->releaseInfo();
		return NULL;
	}
	parentCell->startPathfind(goalCell);

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//
	Int cellCount = 0;
	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		if (parentCell == goalCell)
		{
			// success - found a path to the goal	 
#ifdef INTENSE_DEBUG
	DEBUG_LOG((" time %d msec %d cells", (::GetTickCount()-startTimeMS), cellCount));
	DEBUG_LOG((" SUCCESS\n"));
#endif	
#if defined _DEBUG || defined _INTERNAL
			Bool show = TheGlobalData->m_debugAI==AI_DEBUG_GROUND_PATHS;
			if (show)
				debugShowSearch(true);
#endif
			m_isTunneling = false;
			// construct and return path
			Path *path =  buildGroundPath(crusher, from, goalCell, centerInCell, pathDiameter );
			parentCell->releaseInfo();
			cleanOpenAndClosedLists();
			return path;
		}	

		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );

		// Check to see if we can change layers in this cell.
		checkChangeLayers(parentCell);

		GroundCellsStruct info;
		info.thePathfinder = this;
		info.centerInCell = centerInCell;
		info.pathDiameter = pathDiameter;
		info.goalCell = goalCell;
		info.crusher = crusher;
		ICoord2D start, end;
		start.x = parentCell->getXIndex();
		start.y = parentCell->getYIndex();
		end.x = goalCell->getXIndex();
		end.y = goalCell->getYIndex();
		iterateCellsAlongLine(start, end, parentCell->getLayer(), groundCellsCallback, &info);

		// expand search to neighboring orthogonal cells
		static ICoord2D delta[] = 
		{ 
			{ 1, 0 }, { 0, 1 }, { -1, 0 }, { 0, -1 }, 
			{ 1, 1 }, { -1, 1 }, { -1, -1 }, { 1, -1 } 
		};
		const Int numNeighbors = 8;
		const Int firstDiagonal = 4;
		ICoord2D newCellCoord;
		PathfindCell *newCell;
		const Int adjacent[5] = {0, 1, 2, 3, 0};
		Bool neighborFlags[8] = {false, false, false, false, false, false, false};

		UnsignedInt newCostSoFar;

		for( int i=0; i<numNeighbors; i++ )
		{
			neighborFlags[i] = false;
			// determine neighbor cell to try
			newCellCoord.x = parentCell->getXIndex() + delta[i].x;
			newCellCoord.y = parentCell->getYIndex() + delta[i].y;

			// get the neighboring cell
			newCell = getCell(parentCell->getLayer(), newCellCoord.x, newCellCoord.y );

			// check if cell is on the map
			if (newCell == NULL)
				continue;

			if ((newCell->getLayer()==LAYER_GROUND) && !m_zoneManager.isPassable(newCellCoord.x, newCellCoord.y)) {
				// check if we are within 3.
				Bool passable = false;
				if (m_zoneManager.clipIsPassable(newCellCoord.x+3, newCellCoord.y+3)) passable = true;
				if (m_zoneManager.clipIsPassable(newCellCoord.x-3, newCellCoord.y+3)) passable = true;
				if (m_zoneManager.clipIsPassable(newCellCoord.x+3, newCellCoord.y-3)) passable = true;
				if (m_zoneManager.clipIsPassable(newCellCoord.x-3, newCellCoord.y-3)) passable = true;
				if (!passable) continue;
			}

			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			Bool onList = false;
			if (newCell->hasInfo()) {
				if (newCell->getOpen() || newCell->getClosed())
				{
					// already on one of the lists 
					onList = true;
				}
			}
			Int clearDiameter = 0;
			if (newCell!=goalCell) {

				if (i>=firstDiagonal) {
					// make sure one of the adjacent sides is open.
					if (!neighborFlags[adjacent[i-4]] && !neighborFlags[adjacent[i-3]]) {
						continue;
					}
				}

				// See how wide the cell is.
				clearDiameter = clearCellForDiameter(crusher, newCellCoord.x, newCellCoord.y, newCell->getLayer(), pathDiameter); 
				if (newCell->getType() != PathfindCell::CELL_CLEAR) {
					continue;
				}
				if (newCell->getPinched()) {
					continue;
				}
				neighborFlags[i] = true;

				if (!newCell->allocateInfo(newCellCoord)) {
					// Out of cells for pathing...
 					continue;
				}								
				cellCount++;

				newCostSoFar = newCell->costSoFar( parentCell );
				if (clearDiameter<pathDiameter) {
					int delta = pathDiameter-clearDiameter;
					newCostSoFar += 0.6f*(delta*COST_ORTHOGONAL);
				}
				newCell->setBlockedByAlly(false);
			}
			Int costRemaining = 0;
			costRemaining = newCell->costToGoal( goalCell );

			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			if (onList)
			{
				// already on one of the lists - if existing costSoFar is less, 
				// the new cell is on a longer path, so skip it
				if (newCell->getCostSoFar() <= newCostSoFar)
					continue;
			}
			//DEBUG_LOG(("CELL(%d,%d)L%d CD%d CSF %d, CR%d // ",newCell->getXIndex(), newCell->getYIndex(), 
			//	newCell->getLayer(), clearDiameter, newCostSoFar, costRemaining));
			//if ((cellCount&7)==0) DEBUG_LOG(("\n"));
			newCell->setCostSoFar(newCostSoFar);
			// keep track of path we're building - point back to cell we moved here from
			newCell->setParentCell(parentCell) ;
			newCell->setTotalCost(newCell->getCostSoFar() + costRemaining) ;

			//DEBUG_LOG(("Cell (%d,%d), Parent cost %d, newCostSoFar %d, cost rem %d, tot %d\n", 
			//	newCell->getXIndex(), newCell->getYIndex(), 
			//	newCell->costSoFar(parentCell), newCostSoFar, costRemaining, newCell->getCostSoFar() + costRemaining));

			// if newCell was on closed list, remove it from the list
			if (newCell->getClosed())
				m_closedList = newCell->removeFromClosedList( m_closedList );

			// if the newCell was already on the open list, remove it so it can be re-inserted in order
			if (newCell->getOpen())
				m_openList = newCell->removeFromOpenList( m_openList );

			// insert newCell in open list such that open list is sorted, smallest total path cost first
			m_openList = newCell->putOnSortedOpenList( m_openList );
		}


	}
	// failure - goal cannot be reached
#ifdef INTENSE_DEBUG
	DEBUG_LOG((" FAILURE\n"));
#endif	
#if defined _DEBUG || defined _INTERNAL
	if (TheGlobalData->m_debugAI)
	{
		extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 		RGBColor color;
		color.blue = 0;
		color.red = color.green = 1;
		addIcon(NULL, 0, 0, color);
		debugShowSearch(false);
		Coord3D pos;
		pos = *from;
		pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
		addIcon(&pos, 3*PATHFIND_CELL_SIZE_F, 600, color);
		pos = *to;
		pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
		addIcon(&pos, 3*PATHFIND_CELL_SIZE_F, 600, color);	
		Real dx, dy;
		dx = from->x - to->x;
		dy = from->y - to->y;

		Int count = sqrt(dx*dx+dy*dy)/(PATHFIND_CELL_SIZE_F/2);
		if (count<2) count = 2;
		Int i;
		color.green = 0;
		for (i=1; i<count; i++) {
			pos.x = from->x + (to->x-from->x)*i/count;
			pos.y = from->y + (to->y-from->y)*i/count;
			pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
			addIcon(&pos, PATHFIND_CELL_SIZE_F/2, 60, color);

		}
	}	

	DEBUG_LOG(("%d ", TheGameLogic->getFrame()));
	DEBUG_LOG(("FindGroundPath failed from (%f,%f) to (%f,%f)\n", from->x, from->y, to->x, to->y));
	DEBUG_LOG(("time %f\n", (::GetTickCount()-startTimeMS)/1000.0f));
#endif
#ifdef DUMP_PERF_STATS
	TheGameLogic->incrementOverallFailedPathfinds();
#endif
	m_isTunneling = false;
	goalCell->releaseInfo();
	cleanOpenAndClosedLists();
	return NULL;
}

/**
 * Find a short, valid path between given locations.
 * Uses A* algorithm.
 */
void Pathfinder::processHierarchicalCell( const ICoord2D &scanCell, const ICoord2D &delta, PathfindCell *parentCell, 
																				 PathfindCell *goalCell, UnsignedShort parentZone, 
																				 UnsignedShort *examinedZones, Int &numExZones,
																				 Bool crusher, Int &cellCount)
{
	if (scanCell.x<m_extent.lo.x || scanCell.x>m_extent.hi.x ||
		scanCell.y<m_extent.lo.y || scanCell.y>m_extent.hi.y) {
		return;
	}
	if (parentZone == m_zoneManager.getBlockZone(LOCOMOTORSURFACE_GROUND,
		crusher, scanCell.x, scanCell.y, m_map)) { 
		PathfindCell *newCell = getCell(LAYER_GROUND, scanCell.x, scanCell.y);
		if (newCell->hasInfo() && (newCell->getOpen() || newCell->getClosed())) return; // already looked at this one.
	  ICoord2D adjacentCell = scanCell;
		//DEBUG_ASSERTCRASH(parentZone==newCell->getZone(), ("Different zones?"));
		if (parentZone!=newCell->getZone()) return;
		adjacentCell.x += delta.x;
		adjacentCell.y += delta.y;
		if (adjacentCell.x<m_extent.lo.x || adjacentCell.x>m_extent.hi.x ||
			adjacentCell.y<m_extent.lo.y || adjacentCell.y>m_extent.hi.y) {
			return;
		}
		PathfindCell *adjNewCell = getCell(LAYER_GROUND, adjacentCell.x, adjacentCell.y); 
		if (adjNewCell->hasInfo() && (adjNewCell->getOpen() || adjNewCell->getClosed())) return; // already looked at this one.
		UnsignedShort parentGlobalZone = m_zoneManager.getEffectiveZone(LOCOMOTORSURFACE_GROUND, crusher, parentZone);

		/// @todo - somehow out of bounds or bogus newZone.
		UnsignedShort newZone = m_zoneManager.getBlockZone(LOCOMOTORSURFACE_GROUND,
							crusher, adjacentCell.x, adjacentCell.y, m_map);
		UnsignedShort newGlobalZone = m_zoneManager.getEffectiveZone(LOCOMOTORSURFACE_GROUND, crusher, newZone);
		if (newGlobalZone != parentGlobalZone) {
			return; // can't step over. jba.
		}
		Int j;
		Bool found=false;
		for (j=0; j<numExZones; j++) {
			if (examinedZones[j] == newZone) {
				found = true;
				break;
			}
		}
		if (found) {
			return;
		}
		
		newCell->allocateInfo(scanCell);
		if (!newCell->getClosed() && !newCell->getOpen()) {
			m_closedList = newCell->putOnClosedList(m_closedList);
		}

		adjNewCell->allocateInfo(adjacentCell);
		cellCount++;
		Int curCost = adjNewCell->costToHierGoal(parentCell);
		Int remCost = adjNewCell->costToHierGoal(goalCell);
		if (adjNewCell->getPinched() || newCell->getPinched()) {
			curCost += 2*COST_ORTHOGONAL;
		}	else {
			examinedZones[numExZones] = newZone;
			numExZones++;
		}

		adjNewCell->setCostSoFar(parentCell->getCostSoFar() + curCost);
		adjNewCell->setTotalCost(adjNewCell->getCostSoFar()+remCost);
		adjNewCell->setParentCellHierarchical(parentCell);
		// insert newCell in open list such that open list is sorted, smallest total path cost first
		m_openList = adjNewCell->putOnSortedOpenList( m_openList );

	}
}


/**
 * Find a short, valid path between given locations.
 * Uses A* algorithm.
 */
Path *Pathfinder::findHierarchicalPath( Bool isHuman, const LocomotorSet& locomotorSet, const Coord3D *from, 
													 const Coord3D *to, Bool crusher)
{
	return internal_findHierarchicalPath(isHuman, locomotorSet.getValidSurfaces(), from, to, crusher, FALSE);
}


/**
 * Find a short, valid path between given locations.
 * Uses A* algorithm.
 */
Path *Pathfinder::findClosestHierarchicalPath( Bool isHuman, const LocomotorSet& locomotorSet, const Coord3D *from, 
													 const Coord3D *to, Bool crusher)
{
	return internal_findHierarchicalPath(isHuman, locomotorSet.getValidSurfaces(), from, to, crusher, TRUE);
}



/**
 * Find a short, valid path between given locations.
 * Uses A* algorithm.
 */
Path *Pathfinder::internal_findHierarchicalPath( Bool isHuman, const LocomotorSurfaceTypeMask locomotorSurface, const Coord3D *from, 
													 const Coord3D *rawTo, Bool crusher, Bool closestOK)
{
	//CRCDEBUG_LOG(("Pathfinder::findGroundPath()\n"));
#if defined _DEBUG || defined _INTERNAL
	Int startTimeMS = ::GetTickCount();
#endif
	
	if (rawTo->x == 0.0f && rawTo->y == 0.0f) {
		DEBUG_LOG(("Attempting pathfind to 0,0, generally a bug.\n"));
		return NULL;
	}
	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));
	if (m_isMapReady == false) {
		return NULL;
	}

	Coord3D adjustTo = *rawTo;
	Coord3D *to = &adjustTo;
	Coord3D clipFrom = *from;
	clip(&clipFrom, &adjustTo);

	m_isTunneling = false;

	PathfindLayerEnum destinationLayer = TheTerrainLogic->getLayerForDestination(to);
	
	ICoord2D cell;
	worldToCell( to, &cell );

	// determine goal cell
	PathfindCell *goalCell = getCell( destinationLayer, cell.x, cell.y );
	if (goalCell == NULL) {
		return NULL;
	}
	if (!goalCell->allocateInfo(cell)) {
		return NULL;
	}

	// determine start cell
	ICoord2D startCellNdx;
	PathfindLayerEnum layer = TheTerrainLogic->getLayerForDestination(from);
	PathfindCell *parentCell = getClippedCell( layer,&clipFrom );
	if (parentCell == NULL) {
		return NULL;
	}
	if (parentCell!=goalCell) {
		worldToCell(&clipFrom, &startCellNdx);
		if (!parentCell->allocateInfo(startCellNdx)) {
			goalCell->releaseInfo();
			return NULL;
		}
	}

	Int zone1, zone2;
	// m_isCrusher = false;
	zone1 = m_zoneManager.getEffectiveZone(locomotorSurface, false, parentCell->getZone()); 
	zone2 =  m_zoneManager.getEffectiveZone(locomotorSurface, false, goalCell->getZone());

	if ( zone1 != zone2) {
		goalCell->releaseInfo();
		parentCell->releaseInfo();
		return NULL;
	}

	parentCell->startPathfind(goalCell);

	// "closed" list is initially empty
	m_closedList = NULL;

	Int cellCount = 0;

	UnsignedShort goalBlockZone;
	ICoord2D goalBlockNdx;
	if (goalCell->getLayer()==LAYER_GROUND) {
		goalBlockZone = m_zoneManager.getBlockZone(locomotorSurface,
			crusher, goalCell->getXIndex(), goalCell->getYIndex(), m_map);
		
		goalBlockNdx.x = goalCell->getXIndex()/PathfindZoneManager::ZONE_BLOCK_SIZE;
		goalBlockNdx.y = goalCell->getYIndex()/PathfindZoneManager::ZONE_BLOCK_SIZE;
	}	else {
		goalBlockZone = goalCell->getZone();
		goalBlockNdx.x = -1;
		goalBlockNdx.y = -1;
	}

	if (parentCell->getLayer()==LAYER_GROUND) {
		// initialize "open" list to contain start cell
		m_openList = parentCell;
	}	else {
		m_openList = parentCell;
		PathfindLayerEnum layer = parentCell->getLayer();
		// We're starting on a bridge, so link to land at the bridge end points.
		ICoord2D ndx;
		ICoord2D toNdx;
		m_layers[layer].getStartCellIndex(&ndx);
		m_layers[layer].getEndCellIndex(&toNdx);
 		PathfindCell *cell = getCell(LAYER_GROUND, toNdx.x, toNdx.y);
		PathfindCell *startCell = getCell(LAYER_GROUND, ndx.x, ndx.y);
		if (cell && startCell) {
			// Close parent cell;
			m_openList = parentCell->removeFromOpenList(m_openList);
			m_closedList = parentCell->putOnClosedList(m_closedList);
			startCell->allocateInfo(ndx);
			startCell->setParentCellHierarchical(parentCell);
			cellCount++;
			Int curCost = startCell->costToHierGoal(parentCell);
			Int remCost = startCell->costToHierGoal(goalCell);
			startCell->setCostSoFar(curCost);
			startCell->setTotalCost(remCost);
			startCell->setParentCellHierarchical(parentCell);
			// insert newCell in open list such that open list is sorted, smallest total path cost first
			m_openList = startCell->putOnSortedOpenList( m_openList );

			cellCount++;
			cell->allocateInfo(toNdx);
			curCost = cell->costToHierGoal(parentCell);
			remCost = cell->costToHierGoal(goalCell);
			cell->setCostSoFar(curCost);
			cell->setTotalCost(remCost);
			cell->setParentCellHierarchical(parentCell);
			// insert newCell in open list such that open list is sorted, smallest total path cost first
			m_openList = cell->putOnSortedOpenList( m_openList );
		}
	}

	PathfindCell *closestCell = NULL;
	Real closestDistSqr = sqr(HUGE_DIST);

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//
	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		UnsignedShort parentZone;
		if (parentCell->getLayer()==LAYER_GROUND) {
			parentZone = m_zoneManager.getBlockZone(locomotorSurface,
				crusher, parentCell->getXIndex(), parentCell->getYIndex(), m_map);
		}	else {
			parentZone = parentCell->getZone();
		}

		Bool reachedGoal = false;
		
		Int blockX = parentCell->getXIndex()/PathfindZoneManager::ZONE_BLOCK_SIZE;
		Int blockY = parentCell->getYIndex()/PathfindZoneManager::ZONE_BLOCK_SIZE;
		if (parentZone == goalBlockZone) {
			if (goalBlockNdx.x == -1 || (blockX==goalBlockNdx.x && blockY == goalBlockNdx.y)) {
				reachedGoal = true;
			} else {
				DEBUG_LOG(("Hmm, got match before correct cell."));
			}
		}

		ICoord2D zoneBlockExtent;
		m_zoneManager.getExtent(zoneBlockExtent);
		
		if (!reachedGoal && m_zoneManager.interactsWithBridge(parentCell->getXIndex(), parentCell->getYIndex())) {
			Int i;
			for (i=0; i<=LAYER_LAST; i++) {
				if (m_layers[i].isUnused() || m_layers[i].isDestroyed()) {
					continue;
				}
				ICoord2D ndx;
				ICoord2D toNdx;
				m_layers[i].getStartCellIndex(&ndx);
				m_layers[i].getEndCellIndex(&toNdx);
				if (ndx.x/PathfindZoneManager::ZONE_BLOCK_SIZE != blockX ||
						ndx.y/PathfindZoneManager::ZONE_BLOCK_SIZE != blockY) {
					m_layers[i].getStartCellIndex(&toNdx);
					m_layers[i].getEndCellIndex(&ndx);
				}
				if (ndx.x<0 || ndx.y<0) continue;
				if (toNdx.x<0 || toNdx.y<0) continue;
				if (ndx.x/PathfindZoneManager::ZONE_BLOCK_SIZE == blockX &&
						ndx.y/PathfindZoneManager::ZONE_BLOCK_SIZE == blockY) {
					// Bridge connects to this block.
					Int bridgeZone = m_zoneManager.getBlockZone(locomotorSurface, crusher, ndx.x, ndx.y, m_map);
					if (bridgeZone != parentZone) {
						continue;
					}
					// We have a winner.
					if (m_layers[i].getZone() == goalBlockZone) {
						reachedGoal = true;
						break;
					}
 					PathfindCell *cell = getCell(LAYER_GROUND, toNdx.x, toNdx.y);
					if (cell==NULL) continue;
					if (cell->hasInfo() && (cell->getClosed() || cell->getOpen())) {
						continue;
					}
					PathfindCell *startCell = getCell(LAYER_GROUND, ndx.x, ndx.y); 
					if (startCell==NULL) continue;
					if (startCell != parentCell) {
						startCell->allocateInfo(ndx);
						startCell->setParentCellHierarchical(parentCell);
						if (!startCell->getClosed() && !startCell->getOpen()) {
							m_closedList = startCell->putOnClosedList(m_closedList);
						}
					}
					cell->allocateInfo(toNdx);
					cell->setParentCellHierarchical(startCell);

					cellCount++;
					Int curCost = cell->costToHierGoal(startCell);
					Int remCost = cell->costToHierGoal(goalCell);

					cell->setCostSoFar(startCell->getCostSoFar() + curCost);
					cell->setTotalCost(cell->getCostSoFar()+remCost);
					cell->setParentCellHierarchical(startCell);
					// insert newCell in open list such that open list is sorted, smallest total path cost first
					m_openList = cell->putOnSortedOpenList( m_openList );

				}
			}
		}

		if (reachedGoal)
		{
			if (parentCell != goalCell) {
				goalCell->setParentCellHierarchical(parentCell);
			}
			// success - found a path to the goal	 

			m_isTunneling = false;
			// construct and return path
			Path *path =  buildHierachicalPath( from, goalCell );
#if defined _DEBUG || defined _INTERNAL
			Bool show = TheGlobalData->m_debugAI==AI_DEBUG_PATHS;
			show |= (TheGlobalData->m_debugAI==AI_DEBUG_GROUND_PATHS);
			if (show)	{
				debugShowSearch(true);
#if 0 // Show hierarchical blocks (big blue ones.)
				Int i, j;
				ICoord2D extent;
				m_zoneManager.getExtent(extent);
				for (i=0; i<extent.x; i++) {
					for (j=0; j<extent.y; j++) {
						extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 						RGBColor color;
						color.blue = 1;
						color.red = color.green = 0;
						Coord3D pos;
						pos.x = ((i+0.5f)*PathfindZoneManager::ZONE_BLOCK_SIZE)*PATHFIND_CELL_SIZE_F ;
						pos.y = ((j+0.5f)*PathfindZoneManager::ZONE_BLOCK_SIZE)*PATHFIND_CELL_SIZE_F ;
						pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
						if (m_zoneManager.isPassable(i*PathfindZoneManager::ZONE_BLOCK_SIZE, j*PathfindZoneManager::ZONE_BLOCK_SIZE)) {
							addIcon(&pos, 5*PATHFIND_CELL_SIZE_F, 300, color);
						}
					}
				}
#endif
			}
#endif
			if (goalCell->hasInfo() && !goalCell->getClosed() && !goalCell->getOpen()) {
				goalCell->releaseInfo();
			}
			parentCell->releaseInfo();
			cleanOpenAndClosedLists();
			return path;
		}	

#if defined _DEBUG || defined _INTERNAL
#if 0 
		Bool show = TheGlobalData->m_debugAI==AI_DEBUG_PATHS;
		show |= (TheGlobalData->m_debugAI==AI_DEBUG_GROUND_PATHS);
		if (show)	{
			extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 			RGBColor color;
			color.blue = 1;
			color.red = 1;
			color.green = 0;
			Coord3D pos;
			pos.x = ((blockX+0.5f)*PathfindZoneManager::ZONE_BLOCK_SIZE)*PATHFIND_CELL_SIZE_F ;
			pos.y = ((blockY+0.5f)*PathfindZoneManager::ZONE_BLOCK_SIZE)*PATHFIND_CELL_SIZE_F ;
			pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
			addIcon(&pos, 5*PATHFIND_CELL_SIZE_F, 300, color);
		}
#endif
#endif
		Real dx = IABS(goalCell->getXIndex()-parentCell->getXIndex());
		Real dy = IABS(goalCell->getYIndex()-parentCell->getYIndex());
		Real distSqr = dx*dx+dy*dy;
		if (distSqr < closestDistSqr) {
			closestCell = parentCell;
			closestDistSqr = distSqr;
		}

		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );

		Int i;
		UnsignedShort examinedZones[PathfindZoneManager::ZONE_BLOCK_SIZE];
		Int numExZones = 0;
		// Left side.
		if (blockX>0) {
			for (i=1; i<=PathfindZoneManager::ZONE_BLOCK_SIZE; i++) {
			ICoord2D scanCell;
				scanCell.x = blockX*PathfindZoneManager::ZONE_BLOCK_SIZE;
				scanCell.y = (blockY*PathfindZoneManager::ZONE_BLOCK_SIZE);
				scanCell.y += PathfindZoneManager::ZONE_BLOCK_SIZE/2;
				Int offset = i>>1;
				if (i&1) offset = -offset;
				scanCell.y += offset;	
				ICoord2D delta;
				delta.x = -1; // left side moves -1.
				delta.y = 0;
				PathfindCell *cell = getCell(LAYER_GROUND, scanCell.x, scanCell.y);
				if (cell==NULL) continue;
				if (cell->hasInfo() && (cell->getClosed() || cell->getOpen())) {
					if (parentZone == m_zoneManager.getBlockZone(locomotorSurface,
						crusher, scanCell.x, scanCell.y, m_map)) { 
						break;
					}
				}
				if (isHuman) {
					if (scanCell.x < m_logicalExtent.lo.x || scanCell.x > m_logicalExtent.hi.x ||
							scanCell.y < m_logicalExtent.lo.y || scanCell.y > m_logicalExtent.hi.y) {
						continue;
					}
				}
				processHierarchicalCell(scanCell, delta, parentCell, 
					goalCell, parentZone, examinedZones, numExZones, crusher, cellCount);
			}
		}
		// Right side.
		if (blockX<zoneBlockExtent.x-1) {
			numExZones = 0;
			for (i=1; i<=PathfindZoneManager::ZONE_BLOCK_SIZE; i++) {
			ICoord2D scanCell;
				scanCell.x = blockX*PathfindZoneManager::ZONE_BLOCK_SIZE;
				scanCell.x += PathfindZoneManager::ZONE_BLOCK_SIZE-1;
				scanCell.y = (blockY*PathfindZoneManager::ZONE_BLOCK_SIZE);
				scanCell.y += PathfindZoneManager::ZONE_BLOCK_SIZE/2;
				Int offset = i>>1;
				if (i&1) offset = -offset;
				scanCell.y += offset;	
				ICoord2D delta;
				delta.x = 1; // right side moves +1.
				delta.y = 0;
				PathfindCell *cell = getCell(LAYER_GROUND, scanCell.x, scanCell.y);
				if (cell==NULL) continue;
				if (cell->hasInfo() && (cell->getClosed() || cell->getOpen())) {
					if (parentZone == m_zoneManager.getBlockZone(locomotorSurface,
						crusher, scanCell.x, scanCell.y, m_map)) { 
						break;
					}
				}
				if (isHuman) {
					if (scanCell.x < m_logicalExtent.lo.x || scanCell.x > m_logicalExtent.hi.x ||
							scanCell.y < m_logicalExtent.lo.y || scanCell.y > m_logicalExtent.hi.y) {
						continue;
					}
				}
				processHierarchicalCell(scanCell, delta, parentCell, 
					goalCell, parentZone, examinedZones, numExZones, crusher, cellCount);
			}
		}
		// Top side.
		if (blockY>0) {
			numExZones = 0;
			for (i=1; i<=PathfindZoneManager::ZONE_BLOCK_SIZE; i++) {
			ICoord2D scanCell;
				scanCell.y = blockY*PathfindZoneManager::ZONE_BLOCK_SIZE;
				scanCell.x = (blockX*PathfindZoneManager::ZONE_BLOCK_SIZE);
				scanCell.x += PathfindZoneManager::ZONE_BLOCK_SIZE/2;
				Int offset = i>>1;
				if (i&1) offset = -offset;
				scanCell.x += offset;	
				ICoord2D delta;
				delta.x = 0; 
				delta.y = -1;	// Top side moves -1.
				PathfindCell *cell = getCell(LAYER_GROUND, scanCell.x, scanCell.y);
				if (cell==NULL) continue;
				if (cell->hasInfo() && (cell->getClosed() || cell->getOpen())) {
					if (parentZone == m_zoneManager.getBlockZone(locomotorSurface,
						crusher, scanCell.x, scanCell.y, m_map)) { 
						break;
					}
				}
				if (isHuman) {
					if (scanCell.x < m_logicalExtent.lo.x || scanCell.x > m_logicalExtent.hi.x ||
							scanCell.y < m_logicalExtent.lo.y || scanCell.y > m_logicalExtent.hi.y) {
						continue;
					}
				}
				processHierarchicalCell(scanCell, delta, parentCell, 
					goalCell, parentZone, examinedZones, numExZones, crusher, cellCount);
			}
		}
		// Bottom side.
		if (blockY<zoneBlockExtent.y-1) {
			numExZones = 0;
			for (i=1; i<=PathfindZoneManager::ZONE_BLOCK_SIZE; i++) {
			ICoord2D scanCell;
				scanCell.y = blockY*PathfindZoneManager::ZONE_BLOCK_SIZE;
				scanCell.y += PathfindZoneManager::ZONE_BLOCK_SIZE-1;
				scanCell.x = (blockX*PathfindZoneManager::ZONE_BLOCK_SIZE);
				scanCell.x += PathfindZoneManager::ZONE_BLOCK_SIZE/2;
				Int offset = i>>1;
				if (i&1) offset = -offset;
				scanCell.x += offset;	
				ICoord2D delta;
				delta.x = 0; 
				delta.y = 1; // Top side moves +1.
				PathfindCell *cell = getCell(LAYER_GROUND, scanCell.x, scanCell.y);
				if (cell==NULL) continue;
				if (cell->hasInfo() && (cell->getClosed() || cell->getOpen())) {
					if (parentZone == m_zoneManager.getBlockZone(locomotorSurface,
						crusher, scanCell.x, scanCell.y, m_map)) { 
						break;
					}
				}
				if (isHuman) {
					if (scanCell.x < m_logicalExtent.lo.x || scanCell.x > m_logicalExtent.hi.x ||
							scanCell.y < m_logicalExtent.lo.y || scanCell.y > m_logicalExtent.hi.y) {
						continue;
					}
				}
				processHierarchicalCell(scanCell, delta, parentCell, 
					goalCell, parentZone, examinedZones, numExZones, crusher, cellCount);
			}
		}
	}

	if (closestOK && closestCell) {
		m_isTunneling = false;
		// construct and return path
		Path *path =  buildHierachicalPath( from, closestCell );
#if defined _DEBUG || defined _INTERNAL
#if 0
		if (TheGlobalData->m_debugAI)
		{
			debugShowSearch(true);
			Int i, j;
			ICoord2D extent;
			m_zoneManager.getExtent(extent);
			for (i=0; i<extent.x; i++) {
				for (j=0; j<extent.y; j++) {
					extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 					RGBColor color;
					color.blue = 1;
					color.red = color.green = 0;
					Coord3D pos;
					pos.x = ((i+0.5f)*PathfindZoneManager::ZONE_BLOCK_SIZE)*PATHFIND_CELL_SIZE_F ;
					pos.y = ((j+0.5f)*PathfindZoneManager::ZONE_BLOCK_SIZE)*PATHFIND_CELL_SIZE_F ;
					pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
					if (m_zoneManager.isPassable(i*PathfindZoneManager::ZONE_BLOCK_SIZE, j*PathfindZoneManager::ZONE_BLOCK_SIZE)) {
						addIcon(&pos, 5*PATHFIND_CELL_SIZE_F, 300, color);
					}
				}
			}
		}
#endif
#endif
		if (goalCell->hasInfo() && !goalCell->getClosed() && !goalCell->getOpen()) {
			goalCell->releaseInfo();
		}
		cleanOpenAndClosedLists();
		return path;
	}

	// failure - goal cannot be reached
#if defined _DEBUG || defined _INTERNAL
	if (TheGlobalData->m_debugAI)
	{
		extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 		RGBColor color;
		color.blue = 0;
		color.red = color.green = 1;
		addIcon(NULL, 0, 0, color);
		debugShowSearch(false);
		Coord3D pos;
		pos = *from;
		pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
		addIcon(&pos, 3*PATHFIND_CELL_SIZE_F, 600, color);
		pos = *to;
		pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
		addIcon(&pos, 3*PATHFIND_CELL_SIZE_F, 600, color);	
		Real dx, dy;
		dx = from->x - to->x;
		dy = from->y - to->y;

		Int count = sqrt(dx*dx+dy*dy)/(PATHFIND_CELL_SIZE_F/2);
		if (count<2) count = 2;
		Int i;
		color.green = 0;
		for (i=1; i<count; i++) {
			pos.x = from->x + (to->x-from->x)*i/count;
			pos.y = from->y + (to->y-from->y)*i/count;
			pos.z = TheTerrainLogic->getGroundHeight( pos.x, pos.y ) + 0.5f;
			addIcon(&pos, PATHFIND_CELL_SIZE_F/2, 60, color);

		}
	}	

	DEBUG_LOG(("%d ", TheGameLogic->getFrame()));
	DEBUG_LOG(("FindHierarchicalPath failed from (%f,%f) to (%f,%f)\n", from->x, from->y, to->x, to->y));
	DEBUG_LOG(("time %f\n", (::GetTickCount()-startTimeMS)/1000.0f));
#endif
#ifdef DUMP_PERF_STATS
	TheGameLogic->incrementOverallFailedPathfinds();
#endif
	m_isTunneling = false;
	goalCell->releaseInfo();
	cleanOpenAndClosedLists();
	return NULL;
}


/**
 * Does any broken bridge join from and to?  
 * True means that if bridge BridgeID is repaired, there is a land path from to to..
 */
Bool Pathfinder::findBrokenBridge(const LocomotorSet& locoSet, 
																	const Coord3D *from, const Coord3D *to, ObjectID *bridgeID) 
{
	// See if terrain or building is blocking the destination.
	PathfindLayerEnum destinationLayer = TheTerrainLogic->getLayerForDestination(to);
	PathfindLayerEnum fromLayer = TheTerrainLogic->getLayerForDestination(from);

	Int zone1, zone2;
	*bridgeID = INVALID_ID;

	PathfindCell *parentCell = getClippedCell(fromLayer, from);
	PathfindCell *goalCell = getClippedCell(destinationLayer, to);
	zone1 = m_zoneManager.getEffectiveZone(locoSet.getValidSurfaces(), false, parentCell->getZone()); 
	zone2 =  m_zoneManager.getEffectiveZone(locoSet.getValidSurfaces(), false, goalCell->getZone());
	zone1 = m_zoneManager.getEffectiveTerrainZone(zone1);
	zone2 = m_zoneManager.getEffectiveTerrainZone(zone2);
	zone1 = m_zoneManager.getEffectiveZone(locoSet.getValidSurfaces(), false, zone1); 
	zone2 =  m_zoneManager.getEffectiveZone(locoSet.getValidSurfaces(), false, zone2);

	// If the terrain is connected using this locomotor set, we can path somehow.
	if (zone1 == zone2) {
		// There is not terrain blocking the from & to.
		return false;
	}

	// Check broken bridges.
	Int i;
	for (i=0; i<=LAYER_LAST; i++) {
		if (m_layers[i].isDestroyed()) {
			if (m_layers[i].connectsZones(&m_zoneManager, locoSet, zone1, zone2)) {
				*bridgeID = m_layers[i].getBridgeID();
				return true;
			}
		}
	}
	return false;
}

/**
 * Does any path exist from 'from' to 'to' given the locomotor set
 * This is the quick check, only looks at whether the terrain is possible or
 * impossible to path over.  Doesn't take other units into account.
 * False means it is impossible to path.
 * True means it is possible given the terrain, but there may be units in the way.
 */
Bool Pathfinder::quickDoesPathExist( const LocomotorSet& locomotorSet, 
																const Coord3D *from, 
																const Coord3D *to )
{
	// See if terrain or building is blocking the destination.
	PathfindLayerEnum destinationLayer = TheTerrainLogic->getLayerForDestination(to);
	PathfindLayerEnum fromLayer = TheTerrainLogic->getLayerForDestination(from);
	Int zone1, zone2;

	PathfindCell *parentCell = getClippedCell(fromLayer, from);
	PathfindCell *goalCell = getClippedCell(destinationLayer, to);
	if (goalCell->getType()==PathfindCell::CELL_CLIFF) {
		return false; // No goals on cliffs.
	}
	Bool doingTerrainZone = false;
	zone1 = m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), false, parentCell->getZone()); 

	if (parentCell->getType() == PathfindCell::CELL_OBSTACLE) {
		doingTerrainZone = true;
	}
	zone2 =  m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), false, goalCell->getZone());
	if (goalCell->getType() == PathfindCell::CELL_OBSTACLE) {
		doingTerrainZone = true;
	}
	if (doingTerrainZone) {
		zone1 = parentCell->getZone();
		zone1 = m_zoneManager.getEffectiveTerrainZone(zone1);
		zone1 = m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), false, zone1); 
		zone1 = m_zoneManager.getEffectiveTerrainZone(zone1);
		zone2 = goalCell->getZone();
		zone2 = m_zoneManager.getEffectiveTerrainZone(zone2);
		zone2 = m_zoneManager.getEffectiveZone(locomotorSet.getValidSurfaces(), false, zone2); 
		zone2 = m_zoneManager.getEffectiveTerrainZone(zone2);
	}
	if (!validMovementPosition(false, destinationLayer, locomotorSet, to)) {
		return false;
	}
	// If the terrain is connected using this locomotor set, we can path somehow.
	if (zone1 == zone2) {
		// There is not terrain blocking the from & to.
		return true;
	}
	return FALSE;  // no path exists

}

/**
 * Does any path exist from 'from' to 'to' given the locomotor set
 * This is the careful check, looks at whether the terrain, buindings and units are possible or
 * impossible to path over.  Takes other units into account.
 * False means it is impossible to path.
 * True means it is possible to path.
 */
Bool Pathfinder::slowDoesPathExist( Object *obj, 
																const Coord3D *from, 
																const Coord3D *to,
																ObjectID ignoreObject)
{
	AIUpdateInterface *ai = obj->getAI();
	if (ai==NULL) {
		return false;
	}
	const LocomotorSet &locoSet = ai->getLocomotorSet();
	m_ignoreObstacleID = ignoreObject;
	Path *path = findPath(obj, locoSet, from, to);
	m_ignoreObstacleID = INVALID_ID;
	Bool found = (path!=NULL);
	if (path) {
		path->deleteInstance();
		path = NULL;
	}
	return found;
}

void Pathfinder::clip( Coord3D *from, Coord3D *to )
{
	ICoord2D fromCell, toCell;
	ICoord2D clipFromCell, clipToCell;
	fromCell.x = REAL_TO_INT_FLOOR(from->x/PATHFIND_CELL_SIZE);
	fromCell.y = REAL_TO_INT_FLOOR(from->y/PATHFIND_CELL_SIZE);
	toCell.x = REAL_TO_INT_FLOOR(to->x/PATHFIND_CELL_SIZE);
	toCell.y = REAL_TO_INT_FLOOR(to->y/PATHFIND_CELL_SIZE);
	if (ClipLine2D(&fromCell, &toCell, &clipFromCell, &clipToCell,&m_extent)) {
		if (fromCell.x!=clipFromCell.x || fromCell.y != clipFromCell.y) {
			from->x = clipFromCell.x*PATHFIND_CELL_SIZE_F + 0.05f;
			from->y = clipFromCell.y*PATHFIND_CELL_SIZE_F + 0.05f;
		}
		if (toCell.x!=clipToCell.x || toCell.y != clipToCell.y) {
			to->x = clipToCell.x*PATHFIND_CELL_SIZE_F + 0.05f;
			to->y = clipToCell.y*PATHFIND_CELL_SIZE_F + 0.05f;
		}
	}

}

Bool Pathfinder::pathDestination( 	Object *obj, const LocomotorSet& locomotorSet, Coord3D *dest, 
		PathfindLayerEnum layer, const Coord3D *groupDest)
{
	//CRCDEBUG_LOG(("Pathfinder::pathDestination()\n"));
	if (m_isMapReady == false) return NULL;
	
	if (!obj) return false;

	Int cellCount = 0;
#define MAX_CELL_COUNT 500

	Coord3D adjustTo = *groupDest;
	Coord3D *to = &adjustTo;
	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));
	// create unique "mark" values for open and closed cells for this pathfind invocation

	Bool isCrusher = obj ? obj->getCrusherLevel() > 0 : false;

	PathfindLayerEnum desiredLayer = TheTerrainLogic->getLayerForDestination(dest);
	// determine desired
	PathfindCell *desiredCell = getClippedCell( desiredLayer,  dest );
	if (desiredCell == NULL)
		return FALSE;

	PathfindLayerEnum goalLayer = TheTerrainLogic->getLayerForDestination(to);
	// determine goal cell
	PathfindCell *goalCell = getClippedCell( goalLayer,  to );
	if (goalCell == NULL)
		return FALSE;


	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}
	Bool center;
	Int radius;
	getRadiusAndCenter(obj, radius, center);

	// determine start cell
	ICoord2D startCellNdx; 
	worldToCell(dest, &startCellNdx);
	PathfindCell *parentCell = getCell( layer, startCellNdx.x, startCellNdx.y );
	if (parentCell == NULL)
		return FALSE;
	ICoord2D pos2d;
	worldToCell(to, &pos2d);
	if (!goalCell->allocateInfo(pos2d)) {
		return FALSE;
	}

	if (parentCell!=goalCell) {
		if (!parentCell->allocateInfo(startCellNdx)) {
			desiredCell->releaseInfo();
			goalCell->releaseInfo();
			return FALSE;
		}
	}

	PathfindCell *closestCell = NULL;
	Real closestDistanceSqr = FLT_MAX;
	Coord3D closestPos;

	if (validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), parentCell ) == false) {
		parentCell->releaseInfo();
		goalCell->releaseInfo();
		return FALSE;
	}

	parentCell->startPathfind(goalCell);

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//
	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		Coord3D pos;
		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );
		if (checkForAdjust(obj, locomotorSet, isHuman, parentCell->getXIndex(), parentCell->getYIndex(), parentCell->getLayer(), 
			radius, center, &pos, groupDest)) { 
			Int dx = IABS(goalCell->getXIndex()-parentCell->getXIndex());
			Int dy = IABS(goalCell->getYIndex()-parentCell->getYIndex());
			Real distSqr = dx*dx+dy*dy;
			//Real cost = (parentCell->getCostSoFar()*(parentCell->getCostSoFar()*COST_TO_DISTANCE_FACTOR))*0.5f;
			//distSqr += sqr(cost);
			if (distSqr < closestDistanceSqr) {
				closestCell = parentCell;
				closestDistanceSqr = distSqr;
				closestPos = pos;
			} else {
				continue;
			}
		} else {
			continue;
		}

		if (cellCount > MAX_CELL_COUNT) {
			continue;
		}
		// Check to see if we can change layers in this cell.
		checkChangeLayers(parentCell);

		// expand search to neighboring orthogonal cells
		static ICoord2D delta[] = 
		{ 
			{ 1, 0 }, { 0, 1 }, { -1, 0 }, { 0, -1 }, 
			{ 1, 1 }, { -1, 1 }, { -1, -1 }, { 1, -1 } 
		};
		const Int numNeighbors = 8;
		const Int firstDiagonal = 4;
		ICoord2D newCellCoord;
		PathfindCell *newCell;
		const Int adjacent[5] = {0, 1, 2, 3, 0};
		Bool neighborFlags[8] = {false, false, false, false, false, false, false};

		UnsignedInt newCostSoFar;

		for( int i=0; i<numNeighbors; i++ )
		{
			neighborFlags[i] = false;
			// determine neighbor cell to try
			newCellCoord.x = parentCell->getXIndex() + delta[i].x;
			newCellCoord.y = parentCell->getYIndex() + delta[i].y;

			// get the neighboring cell
			newCell = getCell(parentCell->getLayer(), newCellCoord.x, newCellCoord.y );

			// check if cell is on the map
			if (newCell == NULL)
				continue;

			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			Bool onList = false;
			if (newCell->hasInfo()) {
				if (newCell->getOpen() || newCell->getClosed())
				{
					// already on one of the lists 
					onList = true;
				}
			}
			if (i>=firstDiagonal) {
				// make sure one of the adjacent sides is open.
				if (!neighborFlags[adjacent[i-4]] && !neighborFlags[adjacent[i-3]]) {
					continue;
				}
			}

			if (!validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), newCell, parentCell )) {
				continue;
			}	

			neighborFlags[i] = true;

			if (!newCell->allocateInfo(newCellCoord)) {
				// Out of cells for pathing...
 				return cellCount;
			}								
			cellCount++;

			newCostSoFar = newCell->costSoFar( parentCell );
			newCell->setBlockedByAlly(false);

			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			if (onList)
			{
				// already on one of the lists - if existing costSoFar is less, 
				// the new cell is on a longer path, so skip it
				if (newCell->getCostSoFar() <= newCostSoFar)
					continue;
			}

			// keep track of path we're building - point back to cell we moved here from
			newCell->setParentCell(parentCell) ;

			// store cost of this path
			newCell->setCostSoFar(newCostSoFar);
			
			Int costRemaining = 0;
			if (goalCell) {
				costRemaining = newCell->costToGoal( goalCell );
			}

			newCell->setTotalCost(newCell->getCostSoFar() + costRemaining) ;

			//DEBUG_LOG(("Cell (%d,%d), Parent cost %d, newCostSoFar %d, cost rem %d, tot %d\n", 
			//	newCell->getXIndex(), newCell->getYIndex(), 
			//	newCell->costSoFar(parentCell), newCostSoFar, costRemaining, newCell->getCostSoFar() + costRemaining));

			// if newCell was on closed list, remove it from the list
			if (newCell->getClosed())
				m_closedList = newCell->removeFromClosedList( m_closedList );

			// if the newCell was already on the open list, remove it so it can be re-inserted in order
			if (newCell->getOpen())
				m_openList = newCell->removeFromOpenList( m_openList );

			// insert newCell in open list such that open list is sorted, smallest total path cost first
			m_openList = newCell->putOnSortedOpenList( m_openList );
		}
	}

#if defined _DEBUG || defined _INTERNAL
	if (closestCell) {
		debugShowSearch(true);
		*dest = closestPos;
	} else {
		debugShowSearch(true);
	}
#endif
	m_isTunneling = false;
	cleanOpenAndClosedLists();
	goalCell->releaseInfo();
	return false;
}

struct TightenPathStruct
{
	Object *obj;
	const LocomotorSet *locomotorSet;
	PathfindLayerEnum layer;
	Int		radius;
	Bool	center;
	Bool	foundDest;
	Coord3D destPos;
};


/*static*/ Int Pathfinder::tightenPathCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	TightenPathStruct* d = (TightenPathStruct*)userData;
	if (from == NULL || to==NULL) return 0;
	if (d->layer != to->getLayer()) {
		return 0; // abort.
	}
	Coord3D pos;
	if (!TheAI->pathfinder()->checkForAdjust(d->obj, *d->locomotorSet, true, to_x, to_y, to->getLayer(), d->radius, d->center, &pos, NULL)) 
	{
		return 0;	// bail early
	}
	d->foundDest = true; 
	d->destPos = pos;

	return 0;	// keep going
}

/* Returns the cost, which is in the same units as coord3d distance. */
void Pathfinder::tightenPath(Object *obj, const LocomotorSet& locomotorSet, Coord3D *from, 
		const Coord3D *to)
{
	TightenPathStruct info;

	getRadiusAndCenter(obj, info.radius, info.center);
	info.layer = TheTerrainLogic->getLayerForDestination(from);
	info.obj = obj;
	info.locomotorSet = &locomotorSet;
	info.foundDest = false;
	iterateCellsAlongLine(*from, *to, info.layer, tightenPathCallback, &info);
	if (info.foundDest) {
		*from = info.destPos;
	}
}


/* Returns the cost, which is in the same units as coord3d distance. */
Int Pathfinder::checkPathCost(Object *obj, const LocomotorSet& locomotorSet, const Coord3D *from, 
		const Coord3D *rawTo)
{
	//CRCDEBUG_LOG(("Pathfinder::checkPathCost()\n"));
	if (m_isMapReady == false) return NULL;
	enum {MAX_COST = 0x7fff0000};	
	if (!obj) return MAX_COST;

	Int cellCount = 0;
#define MAX_CELL_COUNT 500

	Coord3D adjustTo = *rawTo;
	Coord3D *to = &adjustTo;
	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));
	// create unique "mark" values for open and closed cells for this pathfind invocation

	Bool isCrusher = obj ? obj->getCrusherLevel() > 0 : false;

	PathfindLayerEnum goalLayer = TheTerrainLogic->getLayerForDestination(to);
	// determine goal cell
	PathfindCell *goalCell = getClippedCell( goalLayer,  to );
	if (goalCell == NULL)
		return MAX_COST;


	Bool center;
	Int radius;
	getRadiusAndCenter(obj, radius, center);

	// determine start cell
	ICoord2D startCellNdx; 
	worldToCell(from, &startCellNdx);
	PathfindLayerEnum fromLayer = TheTerrainLogic->getLayerForDestination(from);
	PathfindCell *parentCell = getCell( fromLayer, from );
	if (parentCell == NULL)
		return MAX_COST;
	ICoord2D pos2d;
	worldToCell(to, &pos2d);
	if (!goalCell->allocateInfo(pos2d)) {
		return MAX_COST;
	}

	if (parentCell!=goalCell) {
		if (!parentCell->allocateInfo(startCellNdx)) {
			goalCell->releaseInfo();
			return MAX_COST;
		}
	}

	if (validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), parentCell ) == false) {
		parentCell->releaseInfo();
		goalCell->releaseInfo();
		return MAX_COST;
	}

	parentCell->startPathfind(goalCell);

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//
	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );

		if (parentCell==goalCell) {	 
			Int cost = parentCell->getTotalCost();
			m_isTunneling = false;
			cleanOpenAndClosedLists();
			return cost;
		}

		if (cellCount > MAX_CELL_COUNT) {
			continue;
		}
		// Check to see if we can change layers in this cell.
		checkChangeLayers(parentCell);

		// expand search to neighboring orthogonal cells
		static ICoord2D delta[] = 
		{ 
			{ 1, 0 }, { 0, 1 }, { -1, 0 }, { 0, -1 }, 
			{ 1, 1 }, { -1, 1 }, { -1, -1 }, { 1, -1 } 
		};
		const Int numNeighbors = 8;
		const Int firstDiagonal = 4;
		ICoord2D newCellCoord;
		PathfindCell *newCell;
		const Int adjacent[5] = {0, 1, 2, 3, 0};
		Bool neighborFlags[8] = {false, false, false, false, false, false, false};

		UnsignedInt newCostSoFar;

		for( int i=0; i<numNeighbors; i++ )
		{
			neighborFlags[i] = false;
			// determine neighbor cell to try
			newCellCoord.x = parentCell->getXIndex() + delta[i].x;
			newCellCoord.y = parentCell->getYIndex() + delta[i].y;

			// get the neighboring cell
			newCell = getCell(parentCell->getLayer(), newCellCoord.x, newCellCoord.y );

			// check if cell is on the map
			if (newCell == NULL)
				continue;

			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			Bool onList = false;
			if (newCell->hasInfo()) {
				if (newCell->getOpen() || newCell->getClosed())
				{
					// already on one of the lists 
					onList = true;
				}
			}
			if (i>=firstDiagonal) {
				// make sure one of the adjacent sides is open.
				if (!neighborFlags[adjacent[i-4]] && !neighborFlags[adjacent[i-3]]) {
					continue;
				}
			}

			if (!validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), newCell, parentCell )) {
				continue;
			}	

			neighborFlags[i] = true;

			if (!newCell->allocateInfo(newCellCoord)) {
				// Out of cells for pathing...
 				return cellCount;
			}								
			cellCount++;

			newCostSoFar = newCell->costSoFar( parentCell );
			newCell->setBlockedByAlly(false);

			// check if this neighbor cell is already on the open (waiting to be tried) 
			// or closed (already tried) lists
			if (onList)
			{
				// already on one of the lists - if existing costSoFar is less, 
				// the new cell is on a longer path, so skip it
				if (newCell->getCostSoFar() <= newCostSoFar)
					continue;
			}

			// keep track of path we're building - point back to cell we moved here from
			newCell->setParentCell(parentCell) ;

			// store cost of this path
			newCell->setCostSoFar(newCostSoFar);
			
			Int costRemaining = 0;
			if (goalCell) {
				costRemaining = newCell->costToGoal( goalCell );
			}

			newCell->setTotalCost(newCell->getCostSoFar() + costRemaining) ;

			//DEBUG_LOG(("Cell (%d,%d), Parent cost %d, newCostSoFar %d, cost rem %d, tot %d\n", 
			//	newCell->getXIndex(), newCell->getYIndex(), 
			//	newCell->costSoFar(parentCell), newCostSoFar, costRemaining, newCell->getCostSoFar() + costRemaining));

			// if newCell was on closed list, remove it from the list
			if (newCell->getClosed())
				m_closedList = newCell->removeFromClosedList( m_closedList );

			// if the newCell was already on the open list, remove it so it can be re-inserted in order
			if (newCell->getOpen())
				m_openList = newCell->removeFromOpenList( m_openList );

			// insert newCell in open list such that open list is sorted, smallest total path cost first
			m_openList = newCell->putOnSortedOpenList( m_openList );
		}
	}

	m_isTunneling = false;
	if (goalCell->hasInfo() && !goalCell->getClosed() && !goalCell->getOpen()) {
		goalCell->releaseInfo();
	}
	cleanOpenAndClosedLists();
	return MAX_COST;
}




/**
 * Find a short, valid path between the FROM location and a location NEAR the to location.
 * Uses A* algorithm.
 */
Path *Pathfinder::findClosestPath( Object *obj, const LocomotorSet& locomotorSet, const Coord3D *from, 
																	Coord3D *rawTo, Bool blocked, Real pathCostMultiplier, Bool moveAllies)
{
	//CRCDEBUG_LOG(("Pathfinder::findClosestPath()\n"));
#if defined _DEBUG || defined _INTERNAL
	Int startTimeMS = ::GetTickCount();
#endif
	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}

	if (locomotorSet.getValidSurfaces() == 0) {
		DEBUG_CRASH(("Attempting to path immobile unit."));
		return NULL;
	}

	if (m_isMapReady == false) return NULL;

	m_isTunneling = false;

	if (!obj) return NULL;

	Bool canPathThroughUnits = false;
	if (obj && obj->getAIUpdateInterface()) {
		canPathThroughUnits = obj->getAIUpdateInterface()->canPathThroughUnits();
	}
	Bool centerInCell;
	Int radius;
	getRadiusAndCenter(obj, radius, centerInCell);

	Coord3D adjustTo = *rawTo;
	Coord3D *to = &adjustTo;
	if (!centerInCell) {
		adjustTo.x += PATHFIND_CELL_SIZE_F/2;
		adjustTo.y += PATHFIND_CELL_SIZE_F/2;
	}
	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));
	// create unique "mark" values for open and closed cells for this pathfind invocation

	Bool isCrusher = obj ? obj->getCrusherLevel() > 0 : false;


	Coord3D clipFrom = *from;
	clip(&clipFrom, &adjustTo);

	PathfindLayerEnum destinationLayer = TheTerrainLogic->getLayerForDestination(to);
	// determine goal cell
	PathfindCell *goalCell = getClippedCell( destinationLayer,  to );
	if (goalCell == NULL)
		return NULL;

	if (goalCell->getZone()==0 && destinationLayer==LAYER_WALL) {
		return NULL;
	}

	Bool goalOnObstacle = false;
	if (m_ignoreObstacleID != INVALID_ID) {
		// Check for object on structure.
		// srj sez: check for obstacle on AIRFIELD... only want to do this for things
		// that are "parked" on the airfield, but not for things hovering over an obstacle
		// (eg, a chinook over a supply dock).
		Object *goalObj = TheGameLogic->findObjectByID(m_ignoreObstacleID);
		if (goalObj) {
			PathfindCell *ignoreCell = getClippedCell(goalObj->getLayer(), goalObj->getPosition());
			if ( (goalCell->getObstacleID()==ignoreCell->getObstacleID()) && (goalCell->getObstacleID() != INVALID_ID) ) {
				Object* newObstacle = TheGameLogic->findObjectByID(goalCell->getObstacleID());
				if (newObstacle != NULL && newObstacle->isKindOf(KINDOF_AIRFIELD))
				{
					m_ignoreObstacleID = goalCell->getObstacleID();
					goalOnObstacle = true;
				}	
				else 
				{
					if (m_ignoreObstacleID == goalCell->getObstacleID()) {
						goalOnObstacle = true;
					}
				}
			}
		}
	}

	// determine start cell
	ICoord2D startCellNdx;
	worldToCell(from, &startCellNdx);
 	PathfindCell *parentCell = getClippedCell( obj->getLayer(), &clipFrom );
	if (parentCell == NULL)
		return NULL;

	if (validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), parentCell ) == false) {
		m_isTunneling = true; // We can't move from our current location.  So relax the constraints.
	}
	TCheckMovementInfo info;
	info.cell = startCellNdx;
	info.layer = obj->getLayer();
	info.centerInCell = centerInCell;
	info.radius = radius;
	info.considerTransient = blocked;
	info.acceptableSurfaces = locomotorSet.getValidSurfaces();
	if (!checkForMovement(obj, info) || info.enemyFixed) {
		m_isTunneling = true; // We can't move from our current location.  So relax the constraints.
	}

	Bool gotHierarchicalPath = false;
	if (m_isTunneling) {
		m_zoneManager.setAllPassable(); // can't optimize.
	}	else {
		m_zoneManager.clearPassableFlags();
		Path *hPat = findClosestHierarchicalPath(isHuman, locomotorSet, from, rawTo, false);
		if (hPat) {
			hPat->deleteInstance();
			gotHierarchicalPath = true;
		}	else {
			m_zoneManager.setAllPassable();
		}
	}
	const Bool startedStuck = m_isTunneling;

	ICoord2D pos2d;
	worldToCell(to, &pos2d);
	if (!goalCell->allocateInfo(pos2d)) {
		return NULL;
	}
	if (parentCell!=goalCell) {
		worldToCell(&clipFrom, &pos2d);
		if (!parentCell->allocateInfo(pos2d)) {
			return NULL;
		}
	}
	parentCell->startPathfind(goalCell);

	PathfindCell *closesetCell = NULL;
	Real closestDistanceSqr = FLT_MAX;
	Real closestDistScreenSqr = FLT_MAX;

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;
	Int count = 0;
	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//
	while( m_openList != NULL )
	{
		Real dx;
		Real dy;
		Real distSqr;
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		if (parentCell == goalCell)
		{
			// success - found a path to the goal
			if (!goalOnObstacle) {
				// See if the goal is a valid destination.  If not, accept closest cell.
				if (closesetCell!=NULL && !canPathThroughUnits && !checkDestination(obj, parentCell->getXIndex(), parentCell->getYIndex(), parentCell->getLayer(), radius, centerInCell)) {
					break;
				}
			}

			Bool show = TheGlobalData->m_debugAI;
#ifdef INTENSE_DEBUG
			Int count = 0;
			PathfindCell *cur;
			for (cur = m_closedList; cur; cur=cur->getNextOpen()) {
				count++;
			}
			if (count>1000) {
				show = true;
				DEBUG_LOG(("FCP - cells %d obj %s %x\n", count, obj->getTemplate()->getName().str(), obj));
#ifdef STATE_MACHINE_DEBUG
				if( obj->getAIUpdateInterface() )
				{
					DEBUG_LOG(("State %s\n",  obj->getAIUpdateInterface()->getCurrentStateName().str()));
				}
#endif
				TheScriptEngine->AppendDebugMessage("Big path FCP", false);
			}
#endif
			if (show)
				debugShowSearch(true);
			m_isTunneling = false;
			// construct and return path
			Path *path = buildActualPath( obj, locomotorSet.getValidSurfaces(), from, goalCell, centerInCell, blocked);
			parentCell->releaseInfo();
			goalCell->releaseInfo();
			cleanOpenAndClosedLists();
			return path;
		}	
		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );
		if (!m_isTunneling && checkDestination(obj, parentCell->getXIndex(), parentCell->getYIndex(), parentCell->getLayer(), radius, centerInCell)) {
			if (!startedStuck || validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), parentCell )) {
				dx = IABS(goalCell->getXIndex()-parentCell->getXIndex());
				dy = IABS(goalCell->getYIndex()-parentCell->getYIndex());
				distSqr = dx*dx+dy*dy;		
				if (distSqr<closestDistScreenSqr) {
					closestDistScreenSqr = distSqr;
				}
				distSqr += (parentCell->getCostSoFar()*(parentCell->getCostSoFar()*COST_TO_DISTANCE_FACTOR_SQR))*pathCostMultiplier;
				if (distSqr < closestDistanceSqr) {
					closesetCell = parentCell;
					closestDistanceSqr = distSqr;
				}
			}
		}

		dx = IABS(goalCell->getXIndex()-parentCell->getXIndex());
		dy = IABS(goalCell->getYIndex()-parentCell->getYIndex());
		distSqr = dx*dx+dy*dy;
		// If we are 2x farther than the closest location already found, don't continue.
		if (distSqr > closestDistScreenSqr*4) {
			Bool skip = false;
			if (!gotHierarchicalPath) {
				skip = true;
			}
			if (count>2000) {
				skip = true;
			}
			if (closestDistScreenSqr < 10*10*PATHFIND_CELL_SIZE_F) {
				skip = true;
			}
			if (skip) {
				continue;
			}
		}

		// Check to see if we can change layers in this cell.
		checkChangeLayers(parentCell);

 
		count += examineNeighboringCells(parentCell, goalCell, locomotorSet, isHuman, centerInCell, radius, startCellNdx, obj, NO_ATTACK);
	}

	if (closesetCell) {
		// success - found a path to near the goal

		Bool show = TheGlobalData->m_debugAI;

#ifdef INTENSE_DEBUG
		if (count>5000) {
			show = true;
			DEBUG_LOG(("FCP CC cells %d obj %s %x\n", count, obj->getTemplate()->getName().str(), obj));
#ifdef STATE_MACHINE_DEBUG
			if( obj->getAIUpdateInterface() )
			{
				DEBUG_LOG(("State %s\n",  obj->getAIUpdateInterface()->getCurrentStateName().str()));
			}
#endif

			DEBUG_LOG(("%d ", TheGameLogic->getFrame()));
			DEBUG_LOG(("Pathfind(findClosestPath) chugged from (%f,%f) to (%f,%f), --", from->x, from->y, to->x, to->y));
			DEBUG_LOG(("Unit '%s', time %f\n", obj->getTemplate()->getName().str(), (::GetTickCount()-startTimeMS)/1000.0f));
#ifdef INTENSE_DEBUG
			TheScriptEngine->AppendDebugMessage("Big path FCP CC", false);
#endif
		}
#endif
		if (show)
			debugShowSearch(true);

		m_isTunneling = false;
		rawTo->x = closesetCell->getXIndex()*PATHFIND_CELL_SIZE_F + PATHFIND_CELL_SIZE_F/2.0f;
		rawTo->y = closesetCell->getYIndex()*PATHFIND_CELL_SIZE_F + PATHFIND_CELL_SIZE_F/2.0f;
		// construct and return path
		Path *path = buildActualPath( obj, locomotorSet.getValidSurfaces(), from, closesetCell, centerInCell, blocked );
		goalCell->releaseInfo();
		cleanOpenAndClosedLists();
		return path;
	}

	// failure - goal cannot be reached
#if defined _DEBUG || defined _INTERNAL
	Bool valid;
	valid = validMovementPosition( isCrusher, obj->getLayer(), locomotorSet, to ) ;

	DEBUG_LOG(("%d ", TheGameLogic->getFrame()));
	DEBUG_LOG(("Pathfind(findClosestPath) failed from (%f,%f) to (%f,%f), original valid %d --", from->x, from->y, to->x, to->y, valid));
	DEBUG_LOG(("Unit '%s', time %f\n", obj->getTemplate()->getName().str(), (::GetTickCount()-startTimeMS)/1000.0f));
	if (TheGlobalData->m_debugAI) 
		debugShowSearch(false);
#endif
#ifdef DUMP_PERF_STATS
	TheGameLogic->incrementOverallFailedPathfinds();
#endif
	m_isTunneling = false;
	goalCell->releaseInfo();
	cleanOpenAndClosedLists();
	return NULL;
}


void Pathfinder::adjustCoordToCell(Int cellX, Int cellY, Bool centerInCell, Coord3D &pos, PathfindLayerEnum layer)
{
	if (centerInCell) {
		pos.x = ((Real)cellX + 0.5f) * PATHFIND_CELL_SIZE_F;
		pos.y = ((Real)cellY + 0.5f) * PATHFIND_CELL_SIZE_F;
	} else {
		pos.x = ((Real)cellX+0.05) * PATHFIND_CELL_SIZE_F;
		pos.y = ((Real)cellY+0.05) * PATHFIND_CELL_SIZE_F;
	}
	pos.z = TheTerrainLogic->getLayerHeight( pos.x, pos.y, layer );
}




/**
 * Work backwards from goal cell to construct final path.
 */
Path *Pathfinder::buildActualPath( const Object *obj, LocomotorSurfaceTypeMask acceptableSurfaces, const Coord3D *fromPos, 
																	PathfindCell *goalCell, Bool center, Bool blocked )
{
	DEBUG_ASSERTCRASH( goalCell, ("Pathfinder::buildActualPath: goalCell == NULL") );

	Path *path = newInstance(Path);

	if (goalCell->getPinched() && goalCell->getParentCell() && !goalCell->getParentCell()->getPinched()) {
		goalCell = goalCell->getParentCell();
	}

	prependCells(path, fromPos, goalCell, center);

	// cleanup the path by checking line of sight
	path->optimize(obj, acceptableSurfaces, blocked);

#if defined _DEBUG || defined _INTERNAL
	if (TheGlobalData->m_debugAI==AI_DEBUG_PATHS) 
	{
		extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
 		RGBColor color;
		color.blue = 0;
		color.red = color.green = 1;
		Coord3D pos;
		for( PathNode *node = path->getFirstNode(); node; node = node->getNext() )
		{

			// create objects to show path - they decay

			pos = *node->getPosition();
			color.red = color.green = 1;
			if (node->getLayer() != LAYER_GROUND) {
				color.red = 0;
			}
			addIcon(&pos, PATHFIND_CELL_SIZE_F*.25f, 200, color);
		}

		// show optimized path
		for( node = path->getFirstNode(); node; node = node->getNextOptimized() )
		{
			pos = *node->getPosition();
			addIcon(&pos, PATHFIND_CELL_SIZE_F*.8f, 200, color);
		}
		setDebugPath(path);
	}
#endif
	return path;
}			 

/**
 * Work backwards from goal cell to construct final path.
 */
void Pathfinder::prependCells( Path *path, const Coord3D *fromPos, 
																	PathfindCell *goalCell, Bool center )
{
	// traverse path cells in REVERSE order, creating path in desired order
	// skip the LAST node, as that will be in the same cell as the unit itself - so use the unit's position
	Coord3D pos;
	PathfindCell *cell, *prevCell = NULL;
	Bool goalCellNull = (goalCell->getParentCell()==NULL);
	for( cell = goalCell; cell->getParentCell(); cell = cell->getParentCell() )
	{
		m_zoneManager.setPassable(cell->getXIndex(), cell->getYIndex(), true);
		adjustCoordToCell(cell->getXIndex(), cell->getYIndex(), center, pos, cell->getLayer());
		if (prevCell && cell->getXIndex()==prevCell->getXIndex() && cell->getYIndex()==prevCell->getYIndex()) {
			// transitioning layers.
			PathfindLayerEnum layer = cell->getLayer();
			if (layer==LAYER_GROUND) {
				layer = prevCell->getLayer();
			}
			DEBUG_ASSERTCRASH(layer!=LAYER_GROUND, ("Should have at 1 non-ground layer. jba"));
			path->getFirstNode()->setLayer(layer);
			continue;
		}
		
		Bool canOptimize = true;
		if (cell->getType() == PathfindCell::CELL_CLIFF) {
			if (prevCell && prevCell->getType() != PathfindCell::CELL_CLIFF) {
				if (path->getFirstNode()) {
					path->getFirstNode()->setCanOptimize(false);
				}
			}
		}	else {
			if (prevCell && prevCell->getType() == PathfindCell::CELL_CLIFF) {
				canOptimize = false;
			}
		}

		path->prependNode( &pos, cell->getLayer() );
		path->getFirstNode()->setCanOptimize(canOptimize);
		if (cell->isBlockedByAlly()) {
			path->setBlockedByAlly(true);
		}
		if (prevCell) {
			prevCell->clearParentCell();
		}
		prevCell = cell;
	}
	m_zoneManager.setPassable(cell->getXIndex(), cell->getYIndex(), true);
	if (goalCellNull) {
		// Very short path.
		adjustCoordToCell(cell->getXIndex(), cell->getYIndex(), center, pos, cell->getLayer());
		path->prependNode( &pos, cell->getLayer() );
	}
	// put actual start position as first node on the path, so it begins right at the unit's feet
	if (fromPos->x != path->getFirstNode()->getPosition()->x || fromPos->y != path->getFirstNode()->getPosition()->y) {
		path->prependNode( fromPos, cell->getLayer() );
	}

}			 

void Pathfinder::setDebugPath(Path *newDebugpath) 
{
	if (TheGlobalData->m_debugAI)
	{
		// copy the path for debugging
		if (debugPath)
			debugPath->deleteInstance();

		debugPath = newInstance(Path);
					
		for( PathNode *copyNode = newDebugpath->getFirstNode(); copyNode; copyNode = copyNode->getNextOptimized() )
			debugPath->appendNode( copyNode->getPosition(), copyNode->getLayer() );
	}

}

/**
 * Given two world-space points, call callback for each cell.
 * Uses Bresenham line algorithm from www.gamedev.net.
 */
Int Pathfinder::iterateCellsAlongLine( const Coord3D& startWorld, const Coord3D& endWorld, 
																			PathfindLayerEnum layer, CellAlongLineProc proc, void* userData )
{
	ICoord2D start, end;
	worldToCell( &startWorld, &start );
	worldToCell( &endWorld, &end );
	return iterateCellsAlongLine(start, end, layer, proc, userData);
}
/**
 * Given two world-space points, call callback for each cell.
 * Uses Bresenham line algorithm from www.gamedev.net.
 */
Int Pathfinder::iterateCellsAlongLine( const ICoord2D &start, const ICoord2D &end, 
																			PathfindLayerEnum layer, CellAlongLineProc proc, void* userData )
{
	Int delta_x = abs(end.x - start.x);			// The difference between the x's
	Int delta_y = abs(end.y - start.y);			// The difference between the y's
	Int x = start.x;												// Start x off at the first pixel
	Int y = start.y;												// Start y off at the first pixel

	Int xinc1, xinc2;
	if (end.x >= start.x)								// The x-values are increasing
	{
		xinc1 = 1;
		xinc2 = 1;
	}
	else																// The x-values are decreasing
	{
		xinc1 = -1;
		xinc2 = -1;
	}

	Int yinc1, yinc2;
	if (end.y >= start.y)               // The y-values are increasing
	{
		yinc1 = 1;
		yinc2 = 1;
	}
	else																// The y-values are decreasing
	{
		yinc1 = -1;
		yinc2 = -1;
	}

	Bool checkY = true;
	Int den, num, numadd, numpixels;
	if (delta_x >= delta_y)							// There is at least one x-value for every y-value
	{
		xinc1 = 0;												// Don't change the x when numerator >= denominator
		yinc2 = 0;												// Don't change the y for every iteration
		den = delta_x;
		num = delta_x / 2;
		numadd = delta_y;
		numpixels = delta_x;							// There are more x-values than y-values
	}
	else																// There is at least one y-value for every x-value
	{
		checkY = false;
		xinc2 = 0;												// Don't change the x for every iteration
		yinc1 = 0;												// Don't change the y when numerator >= denominator
		den = delta_y;
		num = delta_y / 2;
		numadd = delta_x;
		numpixels = delta_y;							// There are more y-values than x-values
	}

	PathfindCell* from = NULL;
	for (Int curpixel = 0; curpixel <= numpixels; curpixel++)
	{
		PathfindCell* to = getCell( layer, x, y );
		if (to==NULL) return 0;
		
		Int ret = (*proc)(this, from, to, x, y, userData);
		if (ret != 0)
			return ret;

		num += numadd;										// Increase the numerator by the top of the fraction
		if (num >= den)										// Check if numerator >= denominator
		{
			num -= den;											// Calculate the new numerator value
			x += xinc1;											// Change the x as appropriate
			y += yinc1;											// Change the y as appropriate
			from = to;
			to = getCell( layer, x, y );
			if (to==NULL) return 0;
			Int ret = (*proc)(this, from, to, x, y, userData);
			if (ret != 0)
				return ret;
		}
		x += xinc2;												// Change the x as appropriate
		y += yinc2;												// Change the y as appropriate

		from = to;
	}

	return 0;
}

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

static ObjectID getSlaverID(const Object* o)
{
	for (BehaviorModule** update = o->getBehaviorModules(); *update; ++update)
	{
		SlavedUpdateInterface* sdu = (*update)->getSlavedUpdateInterface();
		if (sdu != NULL)
		{
			return sdu->getSlaverID();
		}
	}
	
	return INVALID_ID;
}

static ObjectID getContainerID(const Object* o)
{
	const Object* container = o ? o->getContainedBy() : NULL;
	return container ? container->getID() : INVALID_ID;
}

struct segmentIntersectsStruct
{
	Object *theTallBuilding;
	ObjectID ignoreBuilding;
};

/*static*/ Int Pathfinder::segmentIntersectsBuildingCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	segmentIntersectsStruct* d = (segmentIntersectsStruct*)userData;

	if (to != NULL && (to->getType() == PathfindCell::CELL_OBSTACLE))
	{
		Object *obj = TheGameLogic->findObjectByID(to->getObstacleID());
		if (obj && obj->isKindOf(KINDOF_AIRCRAFT_PATH_AROUND)) {
			if (obj->getID() == d->ignoreBuilding) {
				return 0;
			}
			d->theTallBuilding = obj;
			return 1;
		}
	}

	return 0;	// keep going
}



struct ViewBlockedStruct
{
	const Object *obj;
	const Object *objOther;
};


/*static*/ Int Pathfinder::lineBlockedByObstacleCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	const ViewBlockedStruct* d = (const ViewBlockedStruct*)userData;

	if (to != NULL && (to->getType() == PathfindCell::CELL_OBSTACLE))
	{

		// we never block our own view!
		if (to->isObstaclePresent(d->obj->getID()))
			return 0;

		// nor does the object we're trying to see!
		if (to->isObstaclePresent(d->objOther->getID()))
			return 0;

		// if the obstacle is our container, ignore it as an obstacle.
		if (to->isObstaclePresent(getContainerID(d->obj)))
			return 0;

		// @todo: if the obstacle is objOther's container, AND it's a "visible" container, ignore it.

		// if the obstacle is the item to which we are slaved, ignore it as an obstacle.
		if (to->isObstaclePresent(getSlaverID(d->obj)))
			return 0;

		// if the obstacle is the item to which objOther is slaved, ignore it as an obstacle.				
		if (to->isObstaclePresent(getSlaverID(d->objOther)))
			return 0;

		// if the obstacle is transparent, ignore it, since this callback is only used for line-of-sight. (srj)
		if (to->isObstacleTransparent())
			return 0;

		return 1;	// bail early
	}

	return 0;	// keep going
}

struct ViewAttackBlockedStruct
{
	const Object *obj;
	const Object *victim;
	const PathfindCell *victimCell;
	Int		skipCount;
};

/*static*/ Int Pathfinder::attackBlockedByObstacleCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	ViewAttackBlockedStruct* d = (ViewAttackBlockedStruct*)userData;

	if (d->skipCount>0) {
		d->skipCount--;
		return 0;
	}
	if (to != NULL && (to->getType() == PathfindCell::CELL_OBSTACLE))
	{
		// we never block our own view!
		if (to->isObstaclePresent(d->obj->getID()))
			return 0;

		if (d->victim) {
			// nor does the object we're trying to attack!
			if (to->isObstaclePresent(d->victim->getID()))
				return 0;
			// if the obstacle is the item to which objOther is slaved, ignore it as an obstacle.				
			if (to->isObstaclePresent(getSlaverID(d->victim)))
				return 0;
		}

		// if the obstacle is our container, ignore it as an obstacle.
		if (to->isObstaclePresent(getContainerID(d->obj)))
			return 0;

		// @todo: if the obstacle is objOther's container, AND it's a "visible" container, ignore it.

		// if the obstacle is the item to which we are slaved, ignore it as an obstacle.
		if (to->isObstaclePresent(getSlaverID(d->obj)))
			return 0;

		if (to->isObstacleTransparent())
			return 0;
		//Kris: Added the check for victimCell because in China01 -- after the intro, NW of your 
		//base is a cream colored building that lies in a negative coord. When you order units to 
		//force attack it, it crashes.
		if( d->victimCell && to->isObstaclePresent( d->victimCell->getObstacleID() ) ) 
		{
			// Victim is inside the bounds of another object.  We don't let this block us, 
			// as usually it is on the edge and it looks like we should be able to shoot it. jba.
			return 0;
		}
		return 1;	// bail early
	}

	return 0;	// keep going
}

//-----------------------------------------------------------------------------
Bool Pathfinder::isViewBlockedByObstacle(const Object* obj, const Object* objOther)
{
	ViewBlockedStruct info;
	info.obj = obj;
	info.objOther = objOther;
	if (objOther && objOther->isSignificantlyAboveTerrain()) {
		return false; // We don't check los to flying objects.  jba.
	}
#if 1
	return isAttackViewBlockedByObstacle(obj, *obj->getPosition(), objOther, *objOther->getPosition());
#else 
	PathfindLayerEnum layer = objOther->getLayer();
	if (layer==LAYER_GROUND) {
		layer = obj->getLayer();
	}
	Int ret = iterateCellsAlongLine(*obj->getPosition(), *objOther->getPosition(), 
		layer, lineBlockedByObstacleCallback, &info);
	return ret != 0;
#endif 
}


//-----------------------------------------------------------------------------
Bool Pathfinder::isAttackViewBlockedByObstacle(const Object* attacker, const Coord3D& attackerPos, const Object* victim, const Coord3D& victimPos)
{
	//CRCDEBUG_LOG(("Pathfinder::isAttackViewBlockedByObstacle() - attackerPos is (%g,%g,%g) (%X,%X,%X)\n",
	//	attackerPos.x, attackerPos.y, attackerPos.z,
	//	AS_INT(attackerPos.x),AS_INT(attackerPos.y),AS_INT(attackerPos.z)));
	//CRCDEBUG_LOG(("Pathfinder::isAttackViewBlockedByObstacle() - victimPos is (%g,%g,%g) (%X,%X,%X)\n",
	//	victimPos.x, victimPos.y, victimPos.z,
	//	AS_INT(victimPos.x),AS_INT(victimPos.y),AS_INT(victimPos.z)));
	// Global switch to turn this off in case it doesn't work.
	if (!TheAI->getAiData()->m_attackUsesLineOfSight) 
	{
		//CRCDEBUG_LOG(("Pathfinder::isAttackViewBlockedByObstacle() 1\n"));
		return false;
	}

	// If the attacker doesn't need line of sight, isn't blocked.
	if (!attacker->isKindOf(KINDOF_ATTACK_NEEDS_LINE_OF_SIGHT)) 
	{
		//CRCDEBUG_LOG(("Pathfinder::isAttackViewBlockedByObstacle() 2\n"));
		return false;
	}

// srj sez: this is a good start at taking terrain into account for attacks, but findAttackPath needs to be smartened also
#define LOS_TERRAIN
#ifdef LOS_TERRAIN
	const Weapon* w = attacker->getCurrentWeapon();
	if (attacker->isKindOf(KINDOF_IMMOBILE)) {
		// Don't take terrain blockage into account, since we can't move around it. jba.
		w = NULL;
	}
	if (w)
	{
		Bool viewBlocked;
		if (victim)
			viewBlocked = !w->isClearGoalFiringLineOfSightTerrain(attacker, attackerPos, victim);
		else
			viewBlocked = !w->isClearGoalFiringLineOfSightTerrain(attacker, attackerPos, victimPos);

		if (viewBlocked)
		{
			//CRCDEBUG_LOG(("Pathfinder::isAttackViewBlockedByObstacle() 3\n"));
			return true;
		}
	}
#endif

	ViewAttackBlockedStruct info;
	info.obj = attacker;
	info.victim = victim;
	PathfindLayerEnum layer = LAYER_GROUND;
	if (victim) {
		layer = victim->getLayer();
	}
	info.victimCell = getCell(layer, &victimPos);
	
	info.skipCount = 0;
	if (attacker->getLayer() != LAYER_GROUND) 
	{
		info.skipCount = 3;	/// srj -- someone wanna tell me what this magic number means?
												/// jba - Yes, it means that if someone is on a bridge, or rooftop, they can see 
												///      3 pathfind cells out of whatever they are standing on.  
												/// srj -- awesome! thank you very much :-)
		if (layer==LAYER_GROUND) {
			layer = attacker->getLayer();
		}
	}

	Int ret = iterateCellsAlongLine(attackerPos, victimPos, layer, attackBlockedByObstacleCallback, &info);
	//CRCDEBUG_LOG(("Pathfinder::isAttackViewBlockedByObstacle() 4\n"));
	return ret != 0;
}

static void computeNormalRadialOffset(const Coord3D& from,	Coord3D& insert, const Coord3D& to, 
																			Object *obj, Real radius)
{
	Real crossProduct;
	Real dx = to.x - from.x;
	Real dy = to.y -from.y;
	Coord3D objPos = *obj->getPosition();


	Real objDx = objPos.x - from.x;
	Real objDy = objPos.y - from.y;

	crossProduct = dx*objDy - dy*objDx;

	Coord3D fromToNormal;
	fromToNormal.z = 0;
	if (crossProduct>0) {
		fromToNormal.x = dy;
		fromToNormal.y = -dx;
	}	else {
		fromToNormal.x = -dy;
		fromToNormal.y = dx;
	}
	fromToNormal.normalize();
	Real length = radius;
	insert = *obj->getPosition();
	insert.x += fromToNormal.x*length;
	insert.y += fromToNormal.y*length;

}

//-----------------------------------------------------------------------------
Bool Pathfinder::segmentIntersectsTallBuilding(const PathNode *curNode, 
										PathNode *nextNode,  ObjectID ignoreBuilding, Coord3D *insertPos1,  Coord3D *insertPos2,  Coord3D *insertPos3 )
{
	segmentIntersectsStruct info;
	info.theTallBuilding = NULL;
	info.ignoreBuilding = ignoreBuilding;

	Coord3D fromPos = *curNode->getPosition();
	Coord3D toPos = *nextNode->getPosition();

	Int i;
	for (i=0; i<2; i++) {
		Int ret = iterateCellsAlongLine(fromPos, toPos, LAYER_GROUND, segmentIntersectsBuildingCallback, &info);
		if (ret!=0 && info.theTallBuilding) {
			// see if toPos is inside the radius of the tall building.
			Coord3D bldgPos = *info.theTallBuilding->getPosition();
			Coord2D delta;
			Real radius = info.theTallBuilding->getGeometryInfo().getBoundingCircleRadius() + 2*PATHFIND_CELL_SIZE_F; 
			delta.x = toPos.x - bldgPos.x;
			delta.y = toPos.y - bldgPos.y;
			if (delta.length() <= radius*0.98) {
				if (delta.length() < 0.1) {
					delta.x = 1;
				}
				delta.normalize();
				delta.x *= radius;
				delta.y *= radius;
				toPos.x = bldgPos.x+delta.x;
				toPos.y = bldgPos.y+delta.y;
				nextNode->setPosition(&toPos);
				continue;
			}
			delta.x = fromPos.x - bldgPos.x;
			delta.y = fromPos.y - bldgPos.y;
			if (delta.length() <= radius*0.98) {
				if (delta.length() < 0.1) {
					delta.x = 1;
				}
				delta.normalize();
				delta.x *= radius;
				delta.y *= radius;
				fromPos.x = bldgPos.x+delta.x;
				fromPos.y = bldgPos.y+delta.y;
			}


			computeNormalRadialOffset(fromPos, *insertPos2, toPos, info.theTallBuilding, radius);
			computeNormalRadialOffset(fromPos, *insertPos1, *insertPos2, info.theTallBuilding, radius);
			computeNormalRadialOffset(*insertPos2, *insertPos3, toPos, info.theTallBuilding, radius);

			return true;
		}
	}

	return false;
}

//-----------------------------------------------------------------------------
Bool Pathfinder::circleClipsTallBuilding(	const Coord3D *from, const Coord3D *to, Real circleRadius, ObjectID ignoreBuilding, Coord3D *adjustTo)
{
	PartitionFilterAcceptByKindOf filterKindof(MAKE_KINDOF_MASK(KINDOF_AIRCRAFT_PATH_AROUND), KINDOFMASK_NONE);
	PartitionFilter *filters[] = { &filterKindof, NULL };
	Object* tallBuilding = ThePartitionManager->getClosestObject(to, circleRadius, FROM_BOUNDINGSPHERE_2D, filters);
	if (tallBuilding) {
		Real radius = tallBuilding->getGeometryInfo().getBoundingCircleRadius() + 2*PATHFIND_CELL_SIZE_F; 
		computeNormalRadialOffset(*from, *adjustTo, *to, tallBuilding, circleRadius+radius);
		Object* otherTallBuilding = ThePartitionManager->getClosestObject(adjustTo, circleRadius, FROM_BOUNDINGSPHERE_2D, filters);
		if (otherTallBuilding && otherTallBuilding!=tallBuilding) {
			radius = otherTallBuilding->getGeometryInfo().getBoundingCircleRadius() + 2*PATHFIND_CELL_SIZE_F; 
			Coord3D tmpTo = *adjustTo;
			computeNormalRadialOffset(*from, *adjustTo, tmpTo, otherTallBuilding, circleRadius+radius);
		}
		return true;
	}
	return false;
}

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

struct LinePassableStruct
{
	const Object *obj;
	LocomotorSurfaceTypeMask acceptableSurfaces;
	Int radius;
	Bool centerInCell;
	Bool blocked;
	Bool allowPinched;
};

/*static*/ Int Pathfinder::linePassableCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	const LinePassableStruct* d = (const LinePassableStruct*)userData;

	Bool isCrusher = d->obj ? d->obj->getCrusherLevel() > 0 : false;
	TCheckMovementInfo info;
	info.cell.x = to_x;
	info.cell.y = to_y;
	info.layer = to->getLayer();
	info.centerInCell = d->centerInCell;
	info.radius = d->radius;
	info.considerTransient = d->blocked;
	info.acceptableSurfaces = d->acceptableSurfaces;
	if (!pathfinder->checkForMovement(d->obj, info))
	{
		return 1;	// bail out
	}

	if (info.allyFixedCount || info.enemyFixed) 
	{
		return 1;	// bail out
	}

	if (!d->allowPinched && to->getPinched()) {
		return 1; // bail out.
	}

	if (from && to->getLayer() != LAYER_GROUND && from->getLayer() == to->getLayer()) {
		if (to->getType() == PathfindCell::CELL_CLEAR) {
			return 0;
		}
	}

	if (pathfinder->validMovementPosition( isCrusher, d->acceptableSurfaces, to, from ) == false)
	{
		return 1;	// bail out
	}

	return 0;	// keep going
}

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

struct GroundPathPassableStruct
{
	Int		diameter;
	Bool	crusher;
};

/*static*/ Int Pathfinder::groundPathPassableCallback(Pathfinder* pathfinder, PathfindCell* from, PathfindCell* to, Int to_x, Int to_y, void* userData)
{
	const GroundPathPassableStruct* d = (const GroundPathPassableStruct*)userData;

	Int curDiameter = pathfinder->clearCellForDiameter(d->crusher, to_x, to_y, to->getLayer(), d->diameter);
	if (curDiameter==d->diameter) return 0;	//  good to go.
	if (from && to->getLayer() != LAYER_GROUND && from->getLayer() == to->getLayer()) {
		return 0;
	}

	return 1;	// failed.
}

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

/**
 * Given two world-space points, check the line of sight between them for any impassible cells.
 * Uses Bresenham line algorithm from www.gamedev.net.
 */
Bool Pathfinder::isLinePassable( const Object *obj, LocomotorSurfaceTypeMask acceptableSurfaces, 
																PathfindLayerEnum layer, const Coord3D& startWorld, 
																const Coord3D& endWorld, Bool blocked, 
																Bool allowPinched)
{
	LinePassableStruct info;
	//CRCDEBUG_LOG(("Pathfinder::isLinePassable(): %d %d %d \n", m_ignoreObstacleID, m_isMapReady, m_isTunneling));

	info.obj = obj;
	info.acceptableSurfaces = acceptableSurfaces;
	getRadiusAndCenter(obj, info.radius, info.centerInCell);
	info.blocked = blocked;
	info.allowPinched = allowPinched;

	Int ret = iterateCellsAlongLine(startWorld, endWorld, layer, linePassableCallback, (void*)&info);
	return ret == 0;
}

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

/**
 * Given two world-space points, check the line of sight between them for any impassible cells.
 * Uses Bresenham line algorithm from www.gamedev.net.
 */
Bool Pathfinder::isGroundPathPassable( Bool isCrusher, const Coord3D& startWorld, PathfindLayerEnum startLayer, 
		const Coord3D& endWorld, Int pathDiameter)
{
	GroundPathPassableStruct info;

	info.diameter = pathDiameter;
	info.crusher = isCrusher;

	Int ret = iterateCellsAlongLine(startWorld, endWorld, startLayer, groundPathPassableCallback, (void*)&info);
	return ret == 0;
}

/** 
 * Classify the cells under the bridge
 * If 'repaired' is true, bridge is repaired 
 * If 'repaired' is false, bridge has been damaged to be impassable 
 */
void Pathfinder::changeBridgeState( PathfindLayerEnum layer, Bool repaired)
{
	if (m_layers[layer].isUnused()) return;	
	if (m_layers[layer].setDestroyed(!repaired)) {
		m_zoneManager.markZonesDirty();
	}
}

void Pathfinder::getRadiusAndCenter(const Object *obj, Int &iRadius, Bool &center)
{
	enum {MAX_RADIUS = 2};
	if (!obj) 
	{
		center = true;
		iRadius = 0;
		return;
	}
	Real diameter = 2*obj->getGeometryInfo().getBoundingCircleRadius();
	if (diameter>PATHFIND_CELL_SIZE_F && diameter<2.0f*PATHFIND_CELL_SIZE_F) {
		diameter = 2.0f*PATHFIND_CELL_SIZE_F;
	}
	iRadius = REAL_TO_INT_FLOOR(diameter/PATHFIND_CELL_SIZE_F+0.3f);
	center = false;	
	if (iRadius==0) iRadius++;
	if (iRadius&1) 
	{
		center = true;
	}
	iRadius /= 2;
	if (iRadius > MAX_RADIUS) 
	{
		iRadius = MAX_RADIUS;
		center = true;
	}
}

/** 
 * Updates the goal cell for an ai unit.
 */
void Pathfinder::updateGoal( Object *obj, const Coord3D *newGoalPos, PathfindLayerEnum layer)
{
	if (obj->isKindOf(KINDOF_IMMOBILE)) {
		// Only consider mobile.
		return;
	}

	AIUpdateInterface *ai = obj->getAIUpdateInterface();
	if (!ai) return; // only consider ai objects.
	if (!ai->isDoingGroundMovement()) {
		updateAircraftGoal(obj, newGoalPos);
		return;
	}

	PathfindLayerEnum originalLayer = obj->getDestinationLayer();

	//DEBUG_LOG(("Object Goal layer is %d\n", layer));
	Bool layerChanged = originalLayer != layer;

	Bool doGround=false;
	Bool doLayer=false;
	if (layer==LAYER_GROUND) {
		doGround = true;
	} else {
		doLayer = true;
		if (TheTerrainLogic->objectInteractsWithBridgeEnd(obj, layer)) {
			doGround = true;
		}
	}

	ICoord2D goalCell = *ai->getPathfindGoalCell();

	Bool centerInCell;
	Int radius;
	ICoord2D newCell;
	getRadiusAndCenter(obj, radius, centerInCell);
	Int numCellsAbove = radius;
	if (centerInCell) numCellsAbove++;
	if (centerInCell) {
		newCell.x = REAL_TO_INT_FLOOR(newGoalPos->x/PATHFIND_CELL_SIZE_F);
		newCell.y = REAL_TO_INT_FLOOR(newGoalPos->y/PATHFIND_CELL_SIZE_F);
	} else {
		newCell.x = REAL_TO_INT_FLOOR(0.5f+newGoalPos->x/PATHFIND_CELL_SIZE_F);
		newCell.y = REAL_TO_INT_FLOOR(0.5f+newGoalPos->y/PATHFIND_CELL_SIZE_F);
	}
	if (!layerChanged && newCell.x==goalCell.x && newCell.y == goalCell.y) {
		return;
	}
	removeGoal(obj);

	obj->setDestinationLayer(layer);
	ai->setPathfindGoalCell(newCell);
	Int i,j;
	ICoord2D cellNdx;

	Bool warn = true;
	for (i=newCell.x-radius; i<newCell.x+numCellsAbove; i++) {
		for (j=newCell.y-radius; j<newCell.y+numCellsAbove; j++) {
			PathfindCell	*cell;
			if (doLayer) {
				cell = getCell(layer, i, j);
				if (cell) {
					if (warn && cell->getGoalUnit()!=INVALID_ID && cell->getGoalUnit() != obj->getID()) {
						warn = false;
						// jba intense debug
						//DEBUG_LOG(, ("Units got stuck close to each other.  jba\n"));
					}	
					cellNdx.x = i;
					cellNdx.y = j;
					cell->setGoalUnit(obj->getID(), cellNdx);
				}
			}
			if (doGround) {
				cell = getCell(LAYER_GROUND, i, j);
				if (cell) {
					if (warn && cell->getGoalUnit()!=INVALID_ID && cell->getGoalUnit() != obj->getID()) {
						warn = false;
						// jba intense debug
						//DEBUG_LOG(, ("Units got stuck close to each other.  jba\n"));
					}
					cellNdx.x = i;
					cellNdx.y = j;
					cell->setGoalUnit(obj->getID(), cellNdx);
				}
			}
		}
	}

}

/** 
 * Updates the goal cell for an ai unit.
 */
void Pathfinder::updateAircraftGoal( Object *obj, const Coord3D *newGoalPos)
{
	if (obj->isKindOf(KINDOF_IMMOBILE)) {
		// Only consider mobile.
		return;
	}
	removeGoal(obj);
	AIUpdateInterface *ai = obj->getAIUpdateInterface();
	if (!ai) return; // only consider ai objects.
	if (ai->isDoingGroundMovement()) {
		return;  // shouldn't really happen, but just in case.
	}

	// For now, we are only doing HOVER, and WINGS.
	if (!ai->isAircraftThatAdjustsDestination()) return;

	ICoord2D goalCell = *ai->getPathfindGoalCell();

	Bool centerInCell;
	Int radius;
	ICoord2D newCell;
	getRadiusAndCenter(obj, radius, centerInCell);
	Int numCellsAbove = radius;
	if (centerInCell) numCellsAbove++;
	if (centerInCell) {
		newCell.x = REAL_TO_INT_FLOOR(newGoalPos->x/PATHFIND_CELL_SIZE_F);
		newCell.y = REAL_TO_INT_FLOOR(newGoalPos->y/PATHFIND_CELL_SIZE_F);
	} else {
		newCell.x = REAL_TO_INT_FLOOR(0.5f+newGoalPos->x/PATHFIND_CELL_SIZE_F);
		newCell.y = REAL_TO_INT_FLOOR(0.5f+newGoalPos->y/PATHFIND_CELL_SIZE_F);
	}
	if (newCell.x==goalCell.x && newCell.y == goalCell.y) {
		return;
	}

	ai->setPathfindGoalCell(newCell);
	Int i,j;
	ICoord2D cellNdx;

	for (i=newCell.x-radius; i<newCell.x+numCellsAbove; i++) {
		for (j=newCell.y-radius; j<newCell.y+numCellsAbove; j++) {
			PathfindCell	*cell;
			cell = getCell(LAYER_GROUND, i, j);
			if (cell) {
				cellNdx.x = i;
				cellNdx.y = j;
				cell->setGoalAircraft(obj->getID(), cellNdx);
			}
		}
	}

}

/** 
 * Removes the goal cell for an ai unit.
 * Used for a unit that is going to be moving several times, like following a waypoint path, 
 * or intentionally collides with other units (like a car bomb). jba
 */
void Pathfinder::removeGoal( Object *obj)
{
	if (obj->isKindOf(KINDOF_IMMOBILE)) {
		// Only consider mobile.
		return;
	}
	AIUpdateInterface *ai = obj->getAIUpdateInterface();
	if (!ai) return; // only consider ai objects.
	ICoord2D goalCell = *ai->getPathfindGoalCell();

	Bool centerInCell;
	Int radius;
	ICoord2D newCell;
	getRadiusAndCenter(obj, radius, centerInCell);
	if (radius==0) {
		radius++;
	}
	Int numCellsAbove = radius;
	if (centerInCell) numCellsAbove++;
	newCell.x = newCell.y = -1;
	if (newCell.x==goalCell.x && newCell.y == goalCell.y) {
		return;
	}
	ICoord2D cellNdx;
	ai->setPathfindGoalCell(newCell);
	Int i,j;
	if (goalCell.x>=0 && goalCell.y>=0) {
		for (i=goalCell.x-radius; i<goalCell.x+numCellsAbove; i++) {
			for (j=goalCell.y-radius; j<goalCell.y+numCellsAbove; j++) {
				PathfindCell	*cell = getCell(LAYER_GROUND, i, j);
				if (cell) {
					if (cell->getGoalUnit()==obj->getID()) {
						cellNdx.x = i;
						cellNdx.y = j;
						cell->setGoalUnit(INVALID_ID, cellNdx);
					}
					if (cell->getGoalAircraft()==obj->getID()) {
						cellNdx.x = i;
						cellNdx.y = j;
						cell->setGoalAircraft(INVALID_ID, cellNdx);
					}
				}
				if (obj->getDestinationLayer()!=LAYER_GROUND) {
					cell = getCell( obj->getDestinationLayer(), i, j);
					if (cell) {
						if (cell->getGoalUnit()==obj->getID()) {
							cellNdx.x = i;
							cellNdx.y = j;
							cell->setGoalUnit(INVALID_ID, cellNdx);
						}
					}
				}
			}
		}
	}
}

/** 
 * Updates the position cell for an ai unit.
 */
void Pathfinder::updatePos( Object *obj, const Coord3D *newPos)
{
	if (obj->isKindOf(KINDOF_IMMOBILE)) 
	{
		// Only consider mobile.
		return;
	}
	if (!m_isMapReady) 
		return;

	AIUpdateInterface *ai = obj->getAIUpdateInterface();
	if (!ai) 
		return; // only consider ai objects.

	ICoord2D curCell = *ai->getCurPathfindCell();
	if (!ai->isDoingGroundMovement()) 
	{
		if (curCell.x>=0 && curCell.y>=0) 
		{
			removePos(obj);
		}
		return;
	}

	Bool centerInCell;
	Int radius;
	ICoord2D newCell;
	getRadiusAndCenter(obj, radius, centerInCell);
	Int numCellsAbove = radius;
	if (centerInCell) 
		numCellsAbove++;
	if (centerInCell) 
	{
		newCell.x = REAL_TO_INT_FLOOR(newPos->x/PATHFIND_CELL_SIZE_F);
		newCell.y = REAL_TO_INT_FLOOR(newPos->y/PATHFIND_CELL_SIZE_F);
	} 
	else 
	{
		newCell.x = REAL_TO_INT_FLOOR(0.5f+newPos->x/PATHFIND_CELL_SIZE_F);
		newCell.y = REAL_TO_INT_FLOOR(0.5f+newPos->y/PATHFIND_CELL_SIZE_F);
	}
	if (newCell.x==curCell.x && newCell.y == curCell.y) 
	{
		return;
	}

	PathfindLayerEnum layer = obj->getLayer();
	Bool doGround=false;
	Bool doLayer=false;
	if (layer==LAYER_GROUND) {
		doGround = true;	// just have to do ground
	} else {
		doLayer = true; // have to do the layer
		if (TheTerrainLogic->objectInteractsWithBridgeEnd(obj, layer)) {
			doGround = true; // In this case, have to both layer & ground, as they overlap here.
		}
	}

	ai->setCurPathfindCell(newCell);
	Int i,j;
	ICoord2D cellNdx;
	//DEBUG_LOG(("Updating unit pos at cell %d, %d\n", newCell.x, newCell.y));
	if (curCell.x>=0 && curCell.y>=0) {
		for (i=curCell.x-radius; i<curCell.x+numCellsAbove; i++) {
			for (j=curCell.y-radius; j<curCell.y+numCellsAbove; j++) {
				cellNdx.x = i;
				cellNdx.y = j;
				PathfindCell	*cell = getCell(layer, i, j);
				if (cell) {
					if (cell->getPosUnit()==obj->getID()) {
						cell->setPosUnit(INVALID_ID, cellNdx);
					}
				}
				if (layer!=LAYER_GROUND) {
					// Remove from the ground, if present.
					cell = getCell(LAYER_GROUND, i, j);
					if (cell) {
						if (cell->getPosUnit()==obj->getID()) {
							cell->setPosUnit(INVALID_ID, cellNdx);
						}
					}
				}
			}
		}
	}
	for (i=newCell.x-radius; i<newCell.x+numCellsAbove; i++) {
		for (j=newCell.y-radius; j<newCell.y+numCellsAbove; j++) {
			PathfindCell	*cell;
			cellNdx.x = i;
			cellNdx.y = j;
			if (doLayer) {
				cell = getCell(layer, i, j);
				if (cell) {
					cell->setPosUnit(obj->getID(), cellNdx);
				}
			}
			if (doGround) {
				cell = getCell(LAYER_GROUND, i, j);
				if (cell) {
					cell->setPosUnit(obj->getID(), cellNdx);
				}
			}
		}
	}
}

/** 
 * Removes the position cell flags for an ai unit.
 */
void Pathfinder::removePos( Object *obj)
{
	if (obj->isKindOf(KINDOF_IMMOBILE)) {
		// Only consider mobile.
		return;
	}
	if (!m_isMapReady) return;
	AIUpdateInterface *ai = obj->getAIUpdateInterface();
	if (!ai) return; // only consider ai objects.
	ICoord2D curCell = *ai->getCurPathfindCell();
	Bool centerInCell;
	Int radius;
	getRadiusAndCenter(obj, radius, centerInCell);
	Int numCellsAbove = radius;
	if (centerInCell) numCellsAbove++;
	PathfindLayerEnum layer = obj->getLayer();

	ICoord2D newCell;
	newCell.x = newCell.y = -1;
	ai->setCurPathfindCell(newCell);

	Int i,j;
	ICoord2D cellNdx;
	//DEBUG_LOG(("Updating unit pos at cell %d, %d\n", newCell.x, newCell.y));
	if (curCell.x>=0 && curCell.y>=0) {
		for (i=curCell.x-radius; i<curCell.x+numCellsAbove; i++) {
			for (j=curCell.y-radius; j<curCell.y+numCellsAbove; j++) {
				cellNdx.x = i;
				cellNdx.y = j;
				PathfindCell	*cell = getCell(layer, i, j);
				if (cell) {
					if (cell->getPosUnit()==obj->getID()) {
						cell->setPosUnit(INVALID_ID, cellNdx);
					}
				}
				if (layer!=LAYER_GROUND) {
					// Remove from the ground, if present.
					cell = getCell(LAYER_GROUND, i, j);
					if (cell) {
						if (cell->getPosUnit()==obj->getID()) {
							cell->setPosUnit(INVALID_ID, cellNdx);
						}
					}
				}
			}
		}
	}
}

/** 
 * Removes a mobile unit from the pathfind grid.
 */
void Pathfinder::removeUnitFromPathfindMap(  Object *obj )
{
	removePos(obj);
	removeGoal(obj);
}

Bool Pathfinder::moveAllies(Object *obj, Path *path)
{
								 
#ifdef DO_UNIT_TIMINGS
#pragma MESSAGE("*** WARNING *** DOING DO_UNIT_TIMINGS!!!!")
extern Bool g_UT_startTiming;
if (g_UT_startTiming) return false;
#endif
	if (!obj->isKindOf(KINDOF_DOZER) && !obj->isKindOf(KINDOF_HARVESTER)) {
		// Harvesters & dozers want a clear path.
		if (!path->getBlockedByAlly()) return FALSE; // Only move units if it is required.
	}
	LatchRestore<Int> recursiveDepth(m_moveAlliesDepth, m_moveAlliesDepth+1);	
	if (m_moveAlliesDepth > 2) return false;

	Bool centerInCell;
	Int radius;
	getRadiusAndCenter(obj, radius, centerInCell);
	Int numCellsAbove = radius;
	if (centerInCell) numCellsAbove++;
	PathNode *node;
	ObjectID ignoreId = INVALID_ID;
	if (obj->getAIUpdateInterface()) {
		ignoreId = obj->getAIUpdateInterface()->getIgnoredObstacleID();
	}
	for( node = path->getLastNode(); node && node != path->getFirstNode(); node = node->getPrevious() )	{
		ICoord2D curCell;
		worldToCell(node->getPosition(), &curCell);
		Int i, j;
		for (i=curCell.x-radius; i<curCell.x+numCellsAbove; i++) {
			for (j=curCell.y-radius; j<curCell.y+numCellsAbove; j++) {
				PathfindCell	*cell = getCell(node->getLayer(), i, j);
				if (cell) {
					if (cell->getPosUnit()==INVALID_ID) {
						continue;
					}
					if (cell->getPosUnit()==obj->getID()) { 
						continue;	// It's us.
					}
					if (cell->getPosUnit()==ignoreId) { 
						continue;	 // It's the one we are ignoring.
					}
					Object *otherObj = TheGameLogic->findObjectByID(cell->getPosUnit());
					if (obj->getRelationship(otherObj)!=ALLIES) {
						continue;  // Only move allies.
					}
					if (otherObj==NULL) continue;
					if (obj->isKindOf(KINDOF_INFANTRY) && otherObj->isKindOf(KINDOF_INFANTRY)) {
						continue;  // infantry can walk through other infantry, so just let them.
					}
					if (obj->isKindOf(KINDOF_INFANTRY) && !otherObj->isKindOf(KINDOF_INFANTRY)) {
						// If this is a general clear operation, don't let infantry push vehicles.
						if (!path->getBlockedByAlly()) continue;
					}
					if (otherObj && otherObj->getAI() && !otherObj->getAI()->isMoving()) {
						//DEBUG_LOG(("Moving ally\n"));
						otherObj->getAI()->aiMoveAwayFromUnit(obj, CMD_FROM_AI);
					}
				}
			}
		}
	}
	return true;
}


/**
 * Moves an allied unit out of the path of another unit.
 * Uses A* algorithm.
 */
Path *Pathfinder::getMoveAwayFromPath(Object* obj, Object *otherObj,
											Path *pathToAvoid, Object *otherObj2, Path *pathToAvoid2)
{
	if (m_isMapReady == false) return false; // Should always be ok.
#if defined _DEBUG || defined _INTERNAL
	Int startTimeMS = ::GetTickCount();
#endif
	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}
	Bool otherCenter;
	Int otherRadius;
	getRadiusAndCenter(otherObj, otherRadius, otherCenter);

	Bool isCrusher = obj ? obj->getCrusherLevel() > 0 : false;

	m_zoneManager.setAllPassable();

	Bool centerInCell;
	Int radius;
	getRadiusAndCenter(obj, radius, centerInCell);

	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));

	// determine start cell
	ICoord2D startCellNdx;
	Coord3D startPos = *obj->getPosition();
	if (!centerInCell) {
		startPos.x += PATHFIND_CELL_SIZE_F*0.5f;
		startPos.x += PATHFIND_CELL_SIZE_F*0.5f;
	}
	worldToCell(&startPos, &startCellNdx);
	PathfindCell *parentCell = getClippedCell( obj->getLayer(), obj->getPosition() ); 
	if (parentCell == NULL)
		return false;
	if (!obj->getAIUpdateInterface()) {
		return false; // shouldn't happen, but can't move it without an ai.
	}
	const LocomotorSet& locomotorSet = obj->getAIUpdateInterface()->getLocomotorSet();

	m_isTunneling = false;
	if (validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), parentCell ) == false) {
		m_isTunneling = true; // We can't move from our current location.  So relax the constraints.
	}
	
	TCheckMovementInfo info;
	info.cell = startCellNdx;
	info.layer = obj->getLayer();
	info.centerInCell = centerInCell;
	info.radius = radius;
	info.considerTransient = false;
	info.acceptableSurfaces = locomotorSet.getValidSurfaces();
	if (!checkForMovement(obj, info) || info.enemyFixed) {
		m_isTunneling = true; // We can't move from our current location.  So relax the constraints.
	}

	if (!parentCell->allocateInfo(startCellNdx)) {
		return false;
	}
	parentCell->startPathfind(NULL);

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//

	Real boxHalfWidth = radius*PATHFIND_CELL_SIZE_F - (PATHFIND_CELL_SIZE_F/4.0f);
	if (centerInCell) boxHalfWidth+=PATHFIND_CELL_SIZE_F/2;
	boxHalfWidth += otherRadius*PATHFIND_CELL_SIZE_F;
	if (otherCenter) boxHalfWidth+=PATHFIND_CELL_SIZE_F/2;

	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		Region2D bounds;
		Coord3D cellCenter;
		adjustCoordToCell(parentCell->getXIndex(), parentCell->getYIndex(), centerInCell, cellCenter, parentCell->getLayer());
		bounds.lo.x = cellCenter.x-boxHalfWidth;
		bounds.lo.y = cellCenter.y-boxHalfWidth;
		bounds.hi.x = cellCenter.x+boxHalfWidth;
		bounds.hi.y = cellCenter.y+boxHalfWidth;
		PathNode *node;
		Bool overlap = false;
		if (obj) {
			if (bounds.lo.x<obj->getPosition()->x && bounds.hi.x>obj->getPosition()->x &&
				bounds.lo.y<obj->getPosition()->y && bounds.hi.y>obj->getPosition()->y)	{
					//overlap = true;
				}
		}
		for( node = pathToAvoid->getFirstNode(); node && node->getNextOptimized(); node = node->getNextOptimized() )	{
			Coord2D start, end;
			start.x = node->getPosition()->x;
			start.y = node->getPosition()->y;
			end.x = node->getNextOptimized()->getPosition()->x;
			end.y = node->getNextOptimized()->getPosition()->y;
			if (LineInRegion(&start, &end, &bounds)) {
				overlap = true;
				break;
			}
		}
		if (otherObj) {
			if (bounds.lo.x<otherObj->getPosition()->x && bounds.hi.x>otherObj->getPosition()->x &&
				bounds.lo.y<otherObj->getPosition()->y && bounds.hi.y>otherObj->getPosition()->y)	{
					//overlap = true;
				}
		}
		if (!overlap && pathToAvoid2) {
			for( node = pathToAvoid2->getFirstNode(); node && node->getNextOptimized(); node = node->getNextOptimized() )	{
				Coord2D start, end;
				start.x = node->getPosition()->x;
				start.y = node->getPosition()->y;
				end.x = node->getNextOptimized()->getPosition()->x;
				end.y = node->getNextOptimized()->getPosition()->y;
				if (LineInRegion(&start, &end, &bounds)) {
					overlap = true;
					break;
				}
			}
		}
		if (!overlap) {
			if (startCellNdx.x == parentCell->getXIndex() && startCellNdx.y == parentCell->getYIndex()) {
				// we didn't move. Always move at least 1 cell. jba.
				overlap = true;
			}
		}
		///@todo - Adjust cost intersecting path - closer to front is more expensive. jba.
		if (!overlap && checkDestination(obj, parentCell->getXIndex(), parentCell->getYIndex(), 
				parentCell->getLayer(), radius, centerInCell)) {
			// success - found a path to the goal
			if (false && TheGlobalData->m_debugAI)
				debugShowSearch(true);
			m_isTunneling = false;
			// construct and return path
			Path *newPath = buildActualPath( obj, locomotorSet.getValidSurfaces(), obj->getPosition(), parentCell, centerInCell, false);
			parentCell->releaseInfo();
			cleanOpenAndClosedLists();
			return newPath;
		}	
		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );

		// Check to see if we can change layers in this cell.
		checkChangeLayers(parentCell);

		examineNeighboringCells(parentCell, NULL, locomotorSet, isHuman, centerInCell, radius, startCellNdx, obj, NO_ATTACK);

	}

#if defined _DEBUG || defined _INTERNAL
	debugShowSearch(true);
	DEBUG_LOG(("%d ", TheGameLogic->getFrame()));
	DEBUG_LOG(("getMoveAwayFromPath pathfind failed  -- "));
	DEBUG_LOG(("Unit '%s', time %f\n", obj->getTemplate()->getName().str(), (::GetTickCount()-startTimeMS)/1000.0f));
#endif
	m_isTunneling = false;
	cleanOpenAndClosedLists();
	return NULL;
}



/** Patch to the exiting path from the current position, either because we became blocked, 
  or because we had to move off the path to avoid other units. */
Path *Pathfinder::patchPath( const Object *obj, const LocomotorSet& locomotorSet, 
		Path *originalPath, Bool blocked )
{
	//CRCDEBUG_LOG(("Pathfinder::patchPath()\n"));
#if defined _DEBUG || defined _INTERNAL
	Int startTimeMS = ::GetTickCount();
#endif
	if (originalPath==NULL) return NULL;
	Bool centerInCell;
	Int radius;
	getRadiusAndCenter(obj, radius, centerInCell);
	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}

	m_zoneManager.setAllPassable();

	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));

	enum {CELL_LIMIT = 2000}; // max cells to examine.
	Int cellCount = 0;
		 
	Coord3D currentPosition = *obj->getPosition();

	// determine start cell
	ICoord2D startCellNdx;
	Coord3D startPos = *obj->getPosition();
	if (!centerInCell) {
		startPos.x += PATHFIND_CELL_SIZE_F*0.5f;
		startPos.x += PATHFIND_CELL_SIZE_F*0.5f;
	}
	worldToCell(&startPos, &startCellNdx);
	//worldToCell(obj->getPosition(), &startCellNdx);
	PathfindCell *parentCell = getClippedCell( obj->getLayer(), &currentPosition); 
	if (parentCell == NULL)
		return false;
	if (!obj->getAIUpdateInterface()) {
		return false; // shouldn't happen, but can't move it without an ai.
	}

	m_isTunneling = false;
	
	if (!parentCell->allocateInfo(startCellNdx)) {
		return false;
	}
	parentCell->startPathfind( NULL);

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//

#if defined _DEBUG || defined _INTERNAL
	extern void addIcon(const Coord3D *pos, Real width, Int numFramesDuration, RGBColor color);
	if (TheGlobalData->m_debugAI) 
	{
		RGBColor color;
		color.setFromInt(0);
		addIcon(NULL, 0,0,color);
	}
#endif

	PathNode *startNode;
	Coord3D goalPos = *originalPath->getLastNode()->getPosition();
	Real goalDeltaSqr = sqr(goalPos.x-currentPosition.x) + sqr(goalPos.y - currentPosition.y);
	for( startNode = originalPath->getLastNode(); startNode != originalPath->getFirstNode(); startNode = startNode->getPrevious() )	{
		ICoord2D cellCoord;
		worldToCell(startNode->getPosition(), &cellCoord);
		TCheckMovementInfo info;
		info.cell = cellCoord;
		info.layer = startNode->getLayer();
		info.centerInCell = centerInCell;
		info.radius = radius;
		info.considerTransient = blocked;
		info.acceptableSurfaces = locomotorSet.getValidSurfaces();
#if defined _DEBUG || defined _INTERNAL
		if (TheGlobalData->m_debugAI) {
			RGBColor color;
			color.setFromInt(0);
			color.green = 1;
			addIcon(startNode->getPosition(), PATHFIND_CELL_SIZE_F*0.5f, 100, color);
		}
#endif
		Int dx = cellCoord.x-startCellNdx.x;
		Int dy = cellCoord.y-startCellNdx.y;
		if (dx<-2 || dx>2) info.considerTransient = false;
		if (dy<-2 || dy>2) info.considerTransient = false;
		if (!checkForMovement(obj, info)) {
			break;
		}
		if (info.allyFixedCount || info.enemyFixed) {
			break;	// Don't patch through cells that are occupied.
		}	
		Real curSqr = sqr(startNode->getPosition()->x-currentPosition.x) + sqr(startNode->getPosition()->y - currentPosition.y);
		if (curSqr < goalDeltaSqr) {
			goalPos = *startNode->getPosition();
			goalDeltaSqr = curSqr;
		}

	}	
	if (startNode == originalPath->getLastNode()) {
		cleanOpenAndClosedLists();
		return NULL; // no open nodes.
	}
	PathfindCell *candidateGoal;
	candidateGoal = getCell(LAYER_GROUND, &goalPos); // just using for cost estimates.
	ICoord2D goalCellNdx;
	worldToCell(&goalPos, &goalCellNdx);
	if (!candidateGoal->allocateInfo(goalCellNdx)) {
		return NULL;
	}

	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		Coord3D cellCenter;
		adjustCoordToCell(parentCell->getXIndex(), parentCell->getYIndex(), centerInCell, cellCenter, parentCell->getLayer());
		PathNode *matchNode;
		Bool found = false;
		for( matchNode = originalPath->getLastNode(); matchNode != startNode; matchNode = matchNode->getPrevious() )	{
			if (cellCenter.x == matchNode->getPosition()->x && cellCenter.y == matchNode->getPosition()->y)	{
				found = true;
				break;
			}
		}
		if (found ) {
			// success - found a path to the goal
			if ( TheGlobalData->m_debugAI)
				debugShowSearch(true);
			m_isTunneling = false;
			// construct and return path
			Path *path = newInstance(Path);
			PathNode *node;
			for( node = originalPath->getLastNode(); node != matchNode; node = node->getPrevious() )	{	
				path->prependNode(node->getPosition(), node->getLayer());
			}
			prependCells(path, obj->getPosition(), parentCell, centerInCell);

			// cleanup the path by checking line of sight
			path->optimize(obj, locomotorSet.getValidSurfaces(), blocked);
			parentCell->releaseInfo();
			cleanOpenAndClosedLists();
			candidateGoal->releaseInfo();

			return path;
		}	
		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );

		if (cellCount < CELL_LIMIT) {
			// Check to see if we can change layers in this cell.
			checkChangeLayers(parentCell); 
			cellCount += examineNeighboringCells(parentCell, NULL, locomotorSet, isHuman, centerInCell, radius, startCellNdx, obj, NO_ATTACK);
		}
	}

#if defined _DEBUG || defined _INTERNAL
	DEBUG_LOG(("%d ", TheGameLogic->getFrame()));
	DEBUG_LOG(("patchPath Pathfind failed  -- "));
	DEBUG_LOG(("Unit '%s', time %f\n", obj->getTemplate()->getName().str(), (::GetTickCount()-startTimeMS)/1000.0f));
	if (TheGlobalData->m_debugAI) {
		debugShowSearch(true);
	}
#endif
	m_isTunneling = false;
	if (!candidateGoal->getOpen() && !candidateGoal->getClosed())
	{
		// Not on one of the lists 
		candidateGoal->releaseInfo();
	}
	cleanOpenAndClosedLists();
	return false;
}


/** Find a short, valid path to a location that obj can attack victim from.  */
Path *Pathfinder::findAttackPath( const Object *obj, const LocomotorSet& locomotorSet, const Coord3D *from,
		const Object *victim, const Coord3D* victimPos, const Weapon *weapon ) 
{
	/*
	CRCDEBUG_LOG(("Pathfinder::findAttackPath() for object %d (%s)\n", obj->getID(), obj->getTemplate()->getName().str()));
	XferCRC xferCRC;
	xferCRC.open("lightCRC");
	xferCRC.xferSnapshot((Object *)obj);
	xferCRC.close();
	CRCDEBUG_LOG(("obj CRC is %X\n", xferCRC.getCRC()));
	if (from)
	{
		CRCDEBUG_LOG(("from: (%g,%g,%g) (%X,%X,%X)\n",
			from->x, from->y, from->z,
			AS_INT(from->x), AS_INT(from->y), AS_INT(from->z)));
	}
	if (victim)
	{
		CRCDEBUG_LOG(("victim is %d (%s)\n", victim->getID(), victim->getTemplate()->getName().str()));
		XferCRC xferCRC;
		xferCRC.open("lightCRC");
		xferCRC.xferSnapshot((Object *)victim);
		xferCRC.close();
		CRCDEBUG_LOG(("victim CRC is %X\n", xferCRC.getCRC()));
	}
	if (victimPos)
	{
		CRCDEBUG_LOG(("from: (%g,%g,%g) (%X,%X,%X)\n",
			victimPos->x, victimPos->y, victimPos->z,
			AS_INT(victimPos->x), AS_INT(victimPos->y), AS_INT(victimPos->z)));
	}
	*/
	if (m_isMapReady == false) return false; // Should always be ok.
#if defined _DEBUG || defined _INTERNAL
//	Int startTimeMS = ::GetTickCount();
#endif

	Bool isCrusher = obj ? obj->getCrusherLevel() > 0 : false;
	Int radius;
	Bool centerInCell;
	getRadiusAndCenter(obj, radius, centerInCell);

	// Quick check:  See if moving couple of cells towards the victim will work.
	{
		Coord3D curPos = *obj->getPosition();
		Coord3D goalPos = victim?*victim->getPosition():*victimPos;
		Coord3D delta;
		delta.set(goalPos.x-curPos.x, goalPos.y-curPos.y, 0);
		delta.normalize();
		delta.x *= PATHFIND_CELL_SIZE_F;
		delta.y *= PATHFIND_CELL_SIZE_F;
		Int i;
		for (i=1; i<10; i++) {
			Coord3D testPos = curPos;
			testPos.x += delta.x*i*0.5f;
			testPos.y += delta.y*i*0.5f;

			ICoord2D cellNdx;
			worldToCell(&testPos, &cellNdx);
			PathfindCell *aCell = getCell(obj->getLayer(), cellNdx.x, cellNdx.y);
			if (aCell==NULL) break;
			if (!validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), aCell )) {
				break;
			}
			if (!checkDestination(obj, cellNdx.x, cellNdx.y, obj->getLayer(), radius, centerInCell)) {
				break;
			}
			if (weapon->isGoalPosWithinAttackRange(obj, &testPos, victim, victimPos)) {
				if (!isAttackViewBlockedByObstacle(obj, testPos, victim, *victimPos)) {
					// return path.
					Path *path = newInstance(Path);
					path->prependNode( &testPos, obj->getLayer() );
					path->prependNode( &curPos, obj->getLayer() );
					path->getFirstNode()->setNextOptimized(path->getFirstNode()->getNext());
					if (TheGlobalData->m_debugAI==AI_DEBUG_PATHS) {
						setDebugPath(path);
					}
					return path;
				}
			}
		}
	}



	const Int ATTACK_CELL_LIMIT = 2500; // this is a rather expensive operation, so limit the search.

	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}
	m_zoneManager.clearPassableFlags();
	Path *hPat = findClosestHierarchicalPath(isHuman, locomotorSet, from, victimPos, isCrusher);
	if (hPat) {
		hPat->deleteInstance();
	}	else {
		m_zoneManager.setAllPassable();
	}

	Int cellCount = 0;

	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));

	Int attackDistance = weapon->getAttackDistance(obj, victim, victimPos);
	attackDistance += 3*PATHFIND_CELL_SIZE;

		// determine start cell
	ICoord2D startCellNdx;
	Coord3D objPos = *obj->getPosition();
	// since worldtocell truncates, add.
	if (centerInCell) {
		objPos.x += PATHFIND_CELL_SIZE_F/2.0f;
		objPos.y += PATHFIND_CELL_SIZE_F/2.0f;
	}	
	worldToCell(&objPos, &startCellNdx);
	PathfindCell *parentCell = getClippedCell( obj->getLayer(), &objPos ); 
	if (parentCell == NULL)
		return false;
	if (!obj->getAIUpdateInterface()) {
		return false; // shouldn't happen, but can't move it without an ai.
	}
	const PathfindCell *startCell = parentCell;

	if (!parentCell->allocateInfo(startCellNdx)) {
		return false;
	}
	parentCell->startPathfind(NULL);

	// determine start cell
	ICoord2D victimCellNdx;
	worldToCell(victim ? victim->getPosition() : victimPos, &victimCellNdx);

	// determine goal cell
	PathfindCell *goalCell = getCell( LAYER_GROUND, victimCellNdx.x, victimCellNdx.y );
	if (goalCell == NULL)
		return NULL;

 	if (!goalCell->allocateInfo(victimCellNdx)) {
		return false;
	}

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//

	PathfindCell *closestCell = NULL;
	Real closestDistanceSqr = FLT_MAX;
	Bool checkLOS = false;
	if (!victim) {
		checkLOS = true;
	}
	if (victim && !victim->isSignificantlyAboveTerrain()) {
		checkLOS = true;
	}
	
	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		Coord3D cellCenter;
		adjustCoordToCell(parentCell->getXIndex(), parentCell->getYIndex(), centerInCell, cellCenter, parentCell->getLayer());

		///@todo - Adjust cost intersecting path - closer to front is more expensive. jba.
		if (weapon->isGoalPosWithinAttackRange(obj, &cellCenter, victim, victimPos) && 
			checkDestination(obj, parentCell->getXIndex(), parentCell->getYIndex(), 
				parentCell->getLayer(), radius, centerInCell)) {
			// check line of sight.
			Bool viewBlocked = false;
			if (checkLOS) 
			{
				viewBlocked = isAttackViewBlockedByObstacle(obj, cellCenter, victim, *victimPos);
			}
			if (startCell == parentCell) {
				// We never want to accept our starting cell.
				// If we could attack from there, we wouldn't be calling
				// FindAttackPath.  Usually happens cause the cell is valid for attack, but
				// a point near the cell center isn't, and that happens to be where the 
				// attacker is standing, and it's too close to move to.
				viewBlocked = true;
			} else {
				// If through some unfortunate rounding, we end up moving near ourselves, 
				// don't want it.
				Coord3D cellPos;
				adjustCoordToCell(parentCell->getXIndex(), parentCell->getYIndex(), centerInCell, cellPos, parentCell->getLayer());
				Real dx = (cellPos.x - objPos.x);
				Real dy = (cellPos.y - objPos.y);
				if (sqr(dx) + sqr(dy) < sqr(PATHFIND_CELL_SIZE_F*0.5f)) {
					viewBlocked = true;
				}
			}
			if (!viewBlocked) 
			{ 
				// success - found a path to the goal
				Bool show = TheGlobalData->m_debugAI;
	#ifdef INTENSE_DEBUG
				Int count = 0;
				PathfindCell *cur;
				for (cur = m_closedList; cur; cur=cur->getNextOpen()) {
					count++;
				}
				if (count>1000) {
					show = true;
					DEBUG_LOG(("FAP cells %d obj %s %x\n", count, obj->getTemplate()->getName().str(), obj));
	#ifdef STATE_MACHINE_DEBUG
					if( obj->getAIUpdateInterface() )
					{
						DEBUG_LOG(("State %s\n",  obj->getAIUpdateInterface()->getCurrentStateName().str()));
					}
	#endif
					TheScriptEngine->AppendDebugMessage("Big Attack path", false);
				}
	#endif
				if (show)
					debugShowSearch(true);
	#if defined _DEBUG || defined _INTERNAL
				//DEBUG_LOG(("Attack path took %d cells, %f sec\n", cellCount, (::GetTickCount()-startTimeMS)/1000.0f));
	#endif
				// construct and return path
				Path *path = buildActualPath( obj, locomotorSet.getValidSurfaces(), obj->getPosition(), parentCell, centerInCell, false);
				parentCell->releaseInfo();
				if (goalCell->hasInfo() && !goalCell->getClosed() && !goalCell->getOpen()) {
					goalCell->releaseInfo();
				}
				cleanOpenAndClosedLists();
				return path;
			}
		}	
		if (checkDestination(obj, parentCell->getXIndex(), parentCell->getYIndex(), 
																parentCell->getLayer(), radius, centerInCell)) {
			if (validMovementPosition( isCrusher, locomotorSet.getValidSurfaces(), parentCell )) {
				Real dx = IABS(victimCellNdx.x-parentCell->getXIndex());
				Real dy = IABS(victimCellNdx.y-parentCell->getYIndex());
				Real distSqr = dx*dx+dy*dy;
				if (distSqr < closestDistanceSqr) {
					closestCell = parentCell;
					closestDistanceSqr = distSqr;
				}
			}
		}

		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );

		if (cellCount < ATTACK_CELL_LIMIT) {
				// Check to see if we can change layers in this cell.
			checkChangeLayers(parentCell);
			cellCount += examineNeighboringCells(parentCell, goalCell, locomotorSet, isHuman, centerInCell, 
				radius, startCellNdx, obj, attackDistance);
		}

	}

#ifdef INTENSE_DEBUG
	DEBUG_LOG(("obj %s %x\n", obj->getTemplate()->getName().str(), obj));
#ifdef STATE_MACHINE_DEBUG
	if( obj->getAIUpdateInterface() )
	{
		DEBUG_LOG(("State %s\n",  obj->getAIUpdateInterface()->getCurrentStateName().str()));
	}
#endif
	debugShowSearch(true);
	TheScriptEngine->AppendDebugMessage("Overflowed attack path", false);
#endif
#if 0
	if (closestCell) {
		// construct and return path
		Path *path = buildActualPath( obj, locomotorSet, obj->getPosition(), closestCell, centerInCell, false);
		cleanOpenAndClosedLists();
		return path;
	}
#if defined _DEBUG || defined _INTERNAL
	DEBUG_LOG(("%d (%d cells)", TheGameLogic->getFrame(), cellCount));
	DEBUG_LOG(("Attack Pathfind failed from (%f,%f) to (%f,%f) -- \n", from->x, from->y, victim->getPosition()->x, victim->getPosition()->y));
	DEBUG_LOG(("Unit '%s', attacking '%s' time %f\n", obj->getTemplate()->getName().str(),  victim->getTemplate()->getName().str(), (::GetTickCount()-startTimeMS)/1000.0f));
#endif
#endif
#ifdef DUMP_PERF_STATS
	TheGameLogic->incrementOverallFailedPathfinds();
#endif
	m_isTunneling = false;
	if (goalCell->hasInfo() && !goalCell->getClosed() && !goalCell->getOpen()) {
		goalCell->releaseInfo();
	}
	cleanOpenAndClosedLists();
	return false;
}

/** Find a short, valid path to a location that is safe from the repulsors.  */
Path *Pathfinder::findSafePath( const Object *obj, const LocomotorSet& locomotorSet, 
		const Coord3D *from, const Coord3D* repulsorPos1, const Coord3D* repulsorPos2, Real repulsorRadius) 
{
	//CRCDEBUG_LOG(("Pathfinder::findSafePath()\n"));
	if (m_isMapReady == false) return false; // Should always be ok.
#if defined _DEBUG || defined _INTERNAL
//	Int startTimeMS = ::GetTickCount();
#endif

	const Int MAX_CELLS = 2000; // this is a rather expensive operation, so limit the search.

	Bool centerInCell;
	Int radius;
	getRadiusAndCenter(obj, radius, centerInCell);
	Real repulsorDistSqr = repulsorRadius*repulsorRadius;
	Int cellCount = 0;
	Bool isHuman = true;
	if (obj && obj->getControllingPlayer() && (obj->getControllingPlayer()->getPlayerType()==PLAYER_COMPUTER)) {
		isHuman = false; // computer gets to cheat.
	}

	DEBUG_ASSERTCRASH(m_openList==NULL && m_closedList == NULL, ("Dangling lists."));
	// create unique "mark" values for open and closed cells for this pathfind invocation

	m_zoneManager.setAllPassable();
	// determine start cell
	ICoord2D startCellNdx;
	worldToCell(obj->getPosition(), &startCellNdx);
	PathfindCell *parentCell = getClippedCell( obj->getLayer(), obj->getPosition() ); 
	if (parentCell == NULL)
		return false;
	if (!obj->getAIUpdateInterface()) {
		return false; // shouldn't happen, but can't move it without an ai.
	}
	if (!parentCell->allocateInfo(startCellNdx)) {
		return false;
	}
	parentCell->startPathfind( NULL);

	// initialize "open" list to contain start cell
	m_openList = parentCell;

	// "closed" list is initially empty
	m_closedList = NULL;

	//
	// Continue search until "open" list is empty, or
	// until goal is found.
	//

	Real farthestDistanceSqr = 0;

	while( m_openList != NULL )
	{
		// take head cell off of open list - it has lowest estimated total path cost
		parentCell = m_openList;
		m_openList = parentCell->removeFromOpenList(m_openList);

		Coord3D cellCenter;
		adjustCoordToCell(parentCell->getXIndex(), parentCell->getYIndex(), centerInCell, cellCenter, parentCell->getLayer());

		///@todo - Adjust cost intersecting path - closer to front is more expensive. jba.
		Real dx = cellCenter.x-repulsorPos1->x;
		Real dy = cellCenter.y-repulsorPos1->y;
		Bool ok = false;
		Real distSqr = dx*dx+dy*dy;
		dx = cellCenter.x-repulsorPos2->x;
		dy = cellCenter.y-repulsorPos2->y;
		Real distSqr2 = dx*dx+dy*dy;
		if (distSqr2<distSqr) {
			distSqr = distSqr2;
		}
		if (distSqr>repulsorDistSqr) {
			ok = true;
		}
		if (m_openList == NULL && cellCount>0) {
			ok = true; // exhausted the search space, just take the last cell.
		}
		if (distSqr > farthestDistanceSqr) {
			farthestDistanceSqr = distSqr;
			if (cellCount > MAX_CELLS) {
#ifdef INTENSE_DEBUG
				DEBUG_LOG(("Took intermediate path, dist %f, goal dist %f\n", sqrt(farthestDistanceSqr), repulsorRadius));
#endif
				ok = true; // Already a big search, just take this one.
			}
		}
		if ( ok && 
			checkDestination(obj, parentCell->getXIndex(), parentCell->getYIndex(), 
				parentCell->getLayer(), radius, centerInCell)) {
			// success - found a path to the goal
			Bool show = TheGlobalData->m_debugAI;
#ifdef INTENSE_DEBUG
			Int count = 0;
			PathfindCell *cur;
			for (cur = m_closedList; cur; cur=cur->getNextOpen()) {
				count++;
			}
			if (count>2000) {
				show = true;
				DEBUG_LOG(("cells %d obj %s %x\n", count, obj->getTemplate()->getName().str(), obj));
#ifdef STATE_MACHINE_DEBUG
				if( obj->getAIUpdateInterface() )
				{
					DEBUG_LOG(("State %s\n",  obj->getAIUpdateInterface()->getCurrentStateName().str()));
				}
#endif
				TheScriptEngine->AppendDebugMessage("Big Safe path", false);
			}
#endif
			if (show)
				debugShowSearch(true);
#if defined _DEBUG || defined _INTERNAL
			//DEBUG_LOG(("Attack path took %d cells, %f sec\n", cellCount, (::GetTickCount()-startTimeMS)/1000.0f));
#endif
			// construct and return path
			Path *path = buildActualPath( obj, locomotorSet.getValidSurfaces(), obj->getPosition(), parentCell, centerInCell, false);
			parentCell->releaseInfo();
			cleanOpenAndClosedLists();
			return path;
		}	

		// put parent cell onto closed list - its evaluation is finished
		m_closedList = parentCell->putOnClosedList( m_closedList );

		// Check to see if we can change layers in this cell.
		checkChangeLayers(parentCell);

		cellCount += examineNeighboringCells(parentCell, NULL, locomotorSet, isHuman, centerInCell, radius, startCellNdx, obj, NO_ATTACK);

	}

#ifdef INTENSE_DEBUG
	DEBUG_LOG(("obj %s %x count %d\n", obj->getTemplate()->getName().str(), obj, cellCount));
#ifdef STATE_MACHINE_DEBUG
	if( obj->getAIUpdateInterface() )
	{
		DEBUG_LOG(("State %s\n",  obj->getAIUpdateInterface()->getCurrentStateName().str()));
	}
#endif
	TheScriptEngine->AppendDebugMessage("Overflowed Safe path", false);
#endif
#if 0
#if defined _DEBUG || defined _INTERNAL
	DEBUG_LOG(("%d (%d cells)", TheGameLogic->getFrame(), cellCount));
	DEBUG_LOG(("Attack Pathfind failed from (%f,%f) to (%f,%f) -- \n", from->x, from->y, victim->getPosition()->x, victim->getPosition()->y));
	DEBUG_LOG(("Unit '%s', attacking '%s' time %f\n", obj->getTemplate()->getName().str(),  victim->getTemplate()->getName().str(), (::GetTickCount()-startTimeMS)/1000.0f));
#endif
#endif
#ifdef DUMP_PERF_STATS
	TheGameLogic->incrementOverallFailedPathfinds();
#endif
	m_isTunneling = false;
	cleanOpenAndClosedLists();
	return false;
}

//-----------------------------------------------------------------------------
void Pathfinder::crc( Xfer *xfer )
{
	CRCDEBUG_LOG(("Pathfinder::crc() on frame %d\n", TheGameLogic->getFrame()));
	CRCDEBUG_LOG(("beginning CRC: %8.8X\n", ((XferCRC *)xfer)->getCRC()));

	xfer->xferUser( &m_extent, sizeof(IRegion2D) );
	CRCDEBUG_LOG(("m_extent: %8.8X\n", ((XferCRC *)xfer)->getCRC()));

	xfer->xferBool( &m_isMapReady );
	CRCDEBUG_LOG(("m_isMapReady: %8.8X\n", ((XferCRC *)xfer)->getCRC()));
	xfer->xferBool( &m_isTunneling );
	CRCDEBUG_LOG(("m_isTunneling: %8.8X\n", ((XferCRC *)xfer)->getCRC()));

	Int obsolete1 = 0;
	xfer->xferInt( &obsolete1 );

	xfer->xferUser(&m_ignoreObstacleID, sizeof(ObjectID));
	CRCDEBUG_LOG(("m_ignoreObstacleID: %8.8X\n", ((XferCRC *)xfer)->getCRC()));

	xfer->xferUser(m_queuedPathfindRequests, sizeof(ObjectID)*PATHFIND_QUEUE_LEN);
	CRCDEBUG_LOG(("m_queuedPathfindRequests: %8.8X\n", ((XferCRC *)xfer)->getCRC()));
	xfer->xferInt(&m_queuePRHead);
	CRCDEBUG_LOG(("m_queuePRHead: %8.8X\n", ((XferCRC *)xfer)->getCRC()));
	xfer->xferInt(&m_queuePRTail);
	CRCDEBUG_LOG(("m_queuePRTail: %8.8X\n", ((XferCRC *)xfer)->getCRC()));

	xfer->xferInt(&m_numWallPieces);
	CRCDEBUG_LOG(("m_numWallPieces: %8.8X\n", ((XferCRC *)xfer)->getCRC()));
	for (Int i=0; i<MAX_WALL_PIECES; ++i)
	{
		xfer->xferObjectID(&m_wallPieces[MAX_WALL_PIECES]);
	}
	CRCDEBUG_LOG(("m_wallPieces: %8.8X\n", ((XferCRC *)xfer)->getCRC()));

	xfer->xferReal(&m_wallHeight);
	CRCDEBUG_LOG(("m_wallHeight: %8.8X\n", ((XferCRC *)xfer)->getCRC()));
	xfer->xferInt(&m_cumulativeCellsAllocated);
	CRCDEBUG_LOG(("m_cumulativeCellsAllocated: %8.8X\n", ((XferCRC *)xfer)->getCRC()));

}  // end crc

//-----------------------------------------------------------------------------
void Pathfinder::xfer( Xfer *xfer )
{

	// version
	XferVersion currentVersion = 1;
	XferVersion version = currentVersion;
	xfer->xferVersion( &version, currentVersion );

}  // end xfer

//-----------------------------------------------------------------------------
void Pathfinder::loadPostProcess( void )
{

}  // end loadPostProcess