halflife25-sdk/game_shared/bot/nav_file.cpp

// nav_file.cpp
// Reading and writing nav files
// Author: Michael S. Booth (mike@turtlerockstudios.com), January-September 2003

#pragma warning( disable : 4530 )					// STL uses exceptions, but we are not compiling with them - ignore warning
#pragma warning( disable : 4786 )					// long STL names get truncated in browse info.

#include <list>
#include <vector>
#include <algorithm>

#include <fcntl.h>
#include <sys/stat.h>
#include <assert.h>

#ifdef _WIN32
#include <io.h>

#else
#include <unistd.h>
#define _write write
#define _close close
#define MAX_OSPATH PATH_MAX
#endif

#include "extdll.h"
#include "util.h"
#include "cbase.h"
#include "player.h"
#include "gamerules.h"

#include "bot_util.h"

/// @todo Abstract these out of here (TheBotPhrases)
#include "cs_bot.h"
#include "cs_bot_manager.h"

#include "nav.h"
#include "nav_node.h"
#include "nav_area.h"


//
// The 'place directory' is used to save and load places from
// nav files in a size-efficient manner that also allows for the 
// order of the place ID's to change without invalidating the
// nav files.
//
// The place directory is stored in the nav file as a list of 
// place name strings.  Each nav area then contains an index
// into that directory, or zero if no place has been assigned to 
// that area.
//
class PlaceDirectory
{
public:

	typedef unsigned short EntryType;

	void Reset( void )
	{
		m_directory.clear();
	}

	/// return true if this place is already in the directory
	bool IsKnown( Place place ) const
	{
		std::vector<Place>::const_iterator it = std::find( m_directory.begin(), m_directory.end(), place );

		return (it != m_directory.end());
	}

	/// return the directory entry corresponding to this Place (0 = no entry)
	EntryType GetEntry( Place place ) const
	{
		if (place == UNDEFINED_PLACE)
			return 0;

		std::vector<Place>::const_iterator it = std::find( m_directory.begin(), m_directory.end(), place );

		if (it == m_directory.end())
		{
			assert( false && "PlaceDirectory::GetEntry failure" );
			return 0;
		}

		return 1 + (it - m_directory.begin());
	}

	/// add the place to the directory if not already known
	void AddPlace( Place place )
	{
		if (place == UNDEFINED_PLACE)
			return;

		assert( place < 1000 );

		if (IsKnown( place ))
			return;

		m_directory.push_back( place );
	}

	/// given an entry, return the Place
	Place EntryToPlace( EntryType entry ) const
	{
		if (entry == 0)
			return UNDEFINED_PLACE;

		int i = entry-1;

		if (i > m_directory.size())
		{
			assert( false && "PlaceDirectory::EntryToPlace: Invalid entry" );
			return UNDEFINED_PLACE;
		}

		return m_directory[ i ];
	}

	/// store the directory
	void Save( int fd )
	{
		// store number of entries in directory
		EntryType count = m_directory.size();
		_write( fd, &count, sizeof(EntryType) );

		// store entries		
		std::vector<Place>::iterator it;
		for( it = m_directory.begin(); it != m_directory.end(); ++it )
		{
			const char *placeName = TheBotPhrases->IDToName( *it );

			// store string length followed by string itself
			unsigned short len = strlen(placeName)+1;
			_write( fd, &len, sizeof(unsigned short) );
			_write( fd, placeName, len );
		}
	}

	/// load the directory
	bool Load( SteamFile *file )
	{
		// read number of entries
		EntryType count;
		file->Read( &count, sizeof(EntryType) );

		m_directory.reserve( count );

		// read each entry
		char placeName[256];
		unsigned short len;
		for( int i=0; i<count; ++i )
		{
			file->Read( &len, sizeof(unsigned short) );
			if ( len >= sizeof( placeName ) )
			{
				assert( false && "PlaceDirectory::Load: Invalid placeName size" );
				return false;
			}

			file->Read( placeName, len );
			placeName[ sizeof( placeName ) - 1 ] = '\0';

			AddPlace( TheBotPhrases->NameToID( placeName ) );
		}

		return true;
	}

private:
	std::vector<Place> m_directory;
};

static PlaceDirectory placeDirectory;


//--------------------------------------------------------------------------------------------------------------
/**
 * Replace extension with "bsp"
 */
char *GetBspFilename( const char *navFilename )
{
	static char bspFilename[256];

	sprintf( bspFilename, "maps\\%s.bsp", STRING( gpGlobals->mapname ) );

	int len = strlen( bspFilename );
	if (len < 3)
		return NULL;

	bspFilename[ len-3 ] = 'b';
	bspFilename[ len-2 ] = 's';
	bspFilename[ len-1 ] = 'p';

	return bspFilename;
}

//--------------------------------------------------------------------------------------------------------------
void CNavArea::Save( FILE *fp ) const
{
	fprintf( fp, "v  %f %f %f\n", m_extent.lo.x, m_extent.lo.y, m_extent.lo.z );
	fprintf( fp, "v  %f %f %f\n", m_extent.hi.x, m_extent.lo.y, m_neZ );
	fprintf( fp, "v  %f %f %f\n", m_extent.hi.x, m_extent.hi.y, m_extent.hi.z );
	fprintf( fp, "v  %f %f %f\n", m_extent.lo.x, m_extent.hi.y, m_swZ );

	static int base = 1;
	fprintf( fp, "\n\ng %04dArea%s%s%s%s\n", m_id, 
																			(GetAttributes() & NAV_CROUCH) ? "CROUCH" : "",
																			(GetAttributes() & NAV_JUMP) ? "JUMP" : "",
																			(GetAttributes() & NAV_PRECISE) ? "PRECISE" : "",
																			(GetAttributes() & NAV_NO_JUMP) ? "NO_JUMP" : "" );
	fprintf( fp, "f %d %d %d %d\n\n", base, base+1, base+2, base+3 );
	base += 4;
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Save a navigation area to the opened binary stream
 */
void CNavArea::Save( int fd, unsigned int version )
{
	// save ID
	_write( fd, &m_id, sizeof(unsigned int) );

	// save attribute flags
	_write( fd, &m_attributeFlags, sizeof(unsigned char) );

	// save extent of area
	_write( fd, &m_extent, 6*sizeof(float) );

	// save heights of implicit corners
	_write( fd, &m_neZ, sizeof(float) );
	_write( fd, &m_swZ, sizeof(float) );

	// save connections to adjacent areas
	// in the enum order NORTH, EAST, SOUTH, WEST
	for( int d=0; d<NUM_DIRECTIONS; d++ )
	{
		// save number of connections for this direction
		unsigned int count = m_connect[d].size();
		_write( fd, &count, sizeof(unsigned int) );

		NavConnectList::const_iterator iter;
		for( iter = m_connect[d].begin(); iter != m_connect[d].end(); ++iter )
		{
			NavConnect connect = *iter;
			_write( fd, &connect.area->m_id, sizeof(unsigned int) );
		}
	}

	//
	// Store hiding spots for this area
	//
	unsigned char count;
	if (m_hidingSpotList.size() > 255)
	{
		count = 255;
		CONSOLE_ECHO( "Warning: NavArea #%d: Truncated hiding spot list to 255\n", m_id );
	}
	else
	{
		count = m_hidingSpotList.size();
	}
	_write( fd, &count, sizeof(unsigned char) );

	// store HidingSpot objects
	unsigned int saveCount = 0;
	for( HidingSpotList::iterator iter = m_hidingSpotList.begin(); iter != m_hidingSpotList.end(); ++iter )
	{
		HidingSpot *spot = *iter;
		
		spot->Save( fd, version );

		// overflow check
		if (++saveCount == count)
			break;
	}

	//
	// Save the approach areas for this area
	//

	// save number of approach areas
	_write( fd, &m_approachCount, sizeof(unsigned char) );
	if (cv_bot_debug.value > 0.0f)
		CONSOLE_ECHO( "  m_approachCount = %d\n", m_approachCount );

	// save approach area info
	unsigned char type;
	unsigned int zero = 0;
	for( int a=0; a<m_approachCount; ++a )
	{
		if (m_approach[a].here.area)
			_write( fd, &m_approach[a].here.area->m_id, sizeof(unsigned int) );
		else
			_write( fd, &zero, sizeof(unsigned int) );

		if (m_approach[a].prev.area)
			_write( fd, &m_approach[a].prev.area->m_id, sizeof(unsigned int) );
		else
			_write( fd, &zero, sizeof(unsigned int) );
		type = (unsigned char)m_approach[a].prevToHereHow;
		_write( fd, &type, sizeof(unsigned char) );

		if (m_approach[a].next.area)
			_write( fd, &m_approach[a].next.area->m_id, sizeof(unsigned int) );
		else
			_write( fd, &zero, sizeof(unsigned int) );
		type = (unsigned char)m_approach[a].hereToNextHow;
		_write( fd, &type, sizeof(unsigned char) );
	}

	//
	// Save encounter spots for this area
	//
	{
		// save number of encounter paths for this area
		unsigned int count = m_spotEncounterList.size();
		_write( fd, &count, sizeof(unsigned int) );

		if (cv_bot_debug.value > 0.0f)
			CONSOLE_ECHO( "  m_spotEncounterList.size() = %d\n", count );

		SpotEncounter *e;
		for( SpotEncounterList::iterator iter = m_spotEncounterList.begin(); iter != m_spotEncounterList.end(); ++iter )
		{
			e = &(*iter);

			if (e->from.area)
				_write( fd, &e->from.area->m_id, sizeof(unsigned int) );
			else
				_write( fd, &zero, sizeof(unsigned int) );

			unsigned char dir = e->fromDir;
			_write( fd, &dir, sizeof(unsigned char) );

			if (e->to.area)
				_write( fd, &e->to.area->m_id, sizeof(unsigned int) );
			else
				_write( fd, &zero, sizeof(unsigned int) );

			dir = e->toDir;
			_write( fd, &dir, sizeof(unsigned char) );

			// write list of spots along this path
			unsigned char spotCount;
			if (e->spotList.size() > 255)
			{
				spotCount = 255;
				CONSOLE_ECHO( "Warning: NavArea #%d: Truncated encounter spot list to 255\n", m_id );
			}
			else
			{
				spotCount = e->spotList.size();
			}
			_write( fd, &spotCount, sizeof(unsigned char) );
		
			saveCount = 0;
			for( SpotOrderList::iterator oiter = e->spotList.begin(); oiter != e->spotList.end(); ++oiter )
			{
				SpotOrder *order = &(*oiter);

				// order->spot may be NULL if we've loaded a nav mesh that has been edited but not re-analyzed
				unsigned int id = (order->spot) ? order->spot->GetID() : 0;
				_write( fd, &id, sizeof(unsigned int) );

				unsigned char t = 255 * order->t;
				_write( fd, &t, sizeof(unsigned char) );

				// overflow check
				if (++saveCount == spotCount)
					break;
			}
		}
	}

	// store place dictionary entry
	PlaceDirectory::EntryType entry = placeDirectory.GetEntry( GetPlace() );
	_write( fd, &entry, sizeof(entry) );

}

//--------------------------------------------------------------------------------------------------------------
/**
 * Load a navigation area from the file
 */
void CNavArea::Load( SteamFile *file, unsigned int version )
{
	// load ID
	file->Read( &m_id, sizeof(unsigned int) );

	// update nextID to avoid collisions
	if (m_id >= m_nextID)
		m_nextID = m_id+1;

	// load attribute flags
	file->Read( &m_attributeFlags, sizeof(unsigned char) );

	// load extent of area
	file->Read( &m_extent, 6*sizeof(float) );

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

	// load heights of implicit corners
	file->Read( &m_neZ, sizeof(float) );
	file->Read( &m_swZ, sizeof(float) );

	// load connections (IDs) to adjacent areas
	// in the enum order NORTH, EAST, SOUTH, WEST
	for( int d=0; d<NUM_DIRECTIONS; d++ )
	{
		// load number of connections for this direction
		unsigned int count;
		file->Read( &count, sizeof(unsigned int) );

		for( unsigned int i=0; i<count; ++i )
		{
			NavConnect connect;
			file->Read( &connect.id, sizeof(unsigned int) );

			m_connect[d].push_back( connect );
		}
	}

	//
	// Load hiding spots
	//

	// load number of hiding spots
	unsigned char hidingSpotCount;
	file->Read( &hidingSpotCount, sizeof(unsigned char) );

	if (version == 1)
	{
		// load simple vector array
		Vector pos;
		for( int h=0; h<hidingSpotCount; ++h )
		{
			file->Read( &pos, 3 * sizeof(float) );

			// create new hiding spot and put on master list
			HidingSpot *spot = new HidingSpot( &pos, HidingSpot::IN_COVER );

			m_hidingSpotList.push_back( spot );
		}
	}
	else
	{
		// load HidingSpot objects for this area
		for( int h=0; h<hidingSpotCount; ++h )
		{
			// create new hiding spot and put on master list
			HidingSpot *spot = new HidingSpot;

			spot->Load( file, version );
			
			m_hidingSpotList.push_back( spot );
		}
	}

	//
	// Load number of approach areas
	//
	file->Read( &m_approachCount, sizeof(unsigned char) );

	// load approach area info (IDs)
	unsigned char type;
	for( int a=0; a<m_approachCount; ++a )
	{
		file->Read( &m_approach[a].here.id, sizeof(unsigned int) );

		file->Read( &m_approach[a].prev.id, sizeof(unsigned int) );
		file->Read( &type, sizeof(unsigned char) );
		m_approach[a].prevToHereHow = (NavTraverseType)type;

		file->Read( &m_approach[a].next.id, sizeof(unsigned int) );
		file->Read( &type, sizeof(unsigned char) );
		m_approach[a].hereToNextHow = (NavTraverseType)type;
	}


	//
	// Load encounter paths for this area
	//
	unsigned int count;
	file->Read( &count, sizeof(unsigned int) );

	if (version < 3)
	{
		// old data, read and discard
		for( unsigned int e=0; e<count; ++e )
		{
			SpotEncounter encounter;

			file->Read( &encounter.from.id, sizeof(unsigned int) );
			file->Read( &encounter.to.id, sizeof(unsigned int) );

			file->Read( &encounter.path.from.x, 3 * sizeof(float) );
			file->Read( &encounter.path.to.x, 3 * sizeof(float) );

			// read list of spots along this path
			unsigned char spotCount;
			file->Read( &spotCount, sizeof(unsigned char) );
		
			for( int s=0; s<spotCount; ++s )
			{
				Vector pos;
				file->Read( &pos, 3*sizeof(float) );
				file->Read( &pos, sizeof(float) );
			}
		}
		return;
	}

	for( unsigned int e=0; e<count; ++e )
	{
		SpotEncounter encounter;

		file->Read( &encounter.from.id, sizeof(unsigned int) );

		unsigned char dir;
		file->Read( &dir, sizeof(unsigned char) );
		encounter.fromDir = static_cast<NavDirType>( dir );

		file->Read( &encounter.to.id, sizeof(unsigned int) );

		file->Read( &dir, sizeof(unsigned char) );
		encounter.toDir = static_cast<NavDirType>( dir );

		// read list of spots along this path
		unsigned char spotCount;
		file->Read( &spotCount, sizeof(unsigned char) );
	
		SpotOrder order;
		for( int s=0; s<spotCount; ++s )
		{
			file->Read( &order.id, sizeof(unsigned int) );

			unsigned char t;
			file->Read( &t, sizeof(unsigned char) );

			order.t = (float)t/255.0f;

			encounter.spotList.push_back( order );
		}

		m_spotEncounterList.push_back( encounter );
	}

	if (version < 5)
		return;

	//
	// Load Place data
	//
	PlaceDirectory::EntryType entry;
	file->Read( &entry, sizeof(entry) );

	// convert entry to actual Place
	SetPlace( placeDirectory.EntryToPlace( entry ) );
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Convert loaded IDs to pointers
 * Make sure all IDs are converted, even if corrupt data is encountered.
 */
NavErrorType CNavArea::PostLoad( void )
{
	NavErrorType error = NAV_OK;

	// connect areas together
	for( int d=0; d<NUM_DIRECTIONS; d++ )
	{
		NavConnectList::iterator iter;
		for( iter = m_connect[d].begin(); iter != m_connect[d].end(); ++iter )
		{
			NavConnect *connect = &(*iter);

			unsigned int id = connect->id;
			connect->area = TheNavAreaGrid.GetNavAreaByID( id );
			if (id && connect->area == NULL)
			{
				CONSOLE_ECHO( "ERROR: Corrupt navigation data. Cannot connect Navigation Areas.\n" );
				error = NAV_CORRUPT_DATA;
			}
		}		
	}

	// resolve approach area IDs
	for( int a=0; a<m_approachCount; ++a )
	{
		m_approach[a].here.area = TheNavAreaGrid.GetNavAreaByID( m_approach[a].here.id );
		if (m_approach[a].here.id && m_approach[a].here.area == NULL)
		{
			CONSOLE_ECHO( "ERROR: Corrupt navigation data. Missing Approach Area (here).\n" );
			error = NAV_CORRUPT_DATA;
		}

		m_approach[a].prev.area = TheNavAreaGrid.GetNavAreaByID( m_approach[a].prev.id );
		if (m_approach[a].prev.id && m_approach[a].prev.area == NULL)
		{
			CONSOLE_ECHO( "ERROR: Corrupt navigation data. Missing Approach Area (prev).\n" );
			error = NAV_CORRUPT_DATA;
		}

		m_approach[a].next.area = TheNavAreaGrid.GetNavAreaByID( m_approach[a].next.id );
		if (m_approach[a].next.id && m_approach[a].next.area == NULL)
		{
			CONSOLE_ECHO( "ERROR: Corrupt navigation data. Missing Approach Area (next).\n" );
			error = NAV_CORRUPT_DATA;
		}
	}

	// resolve spot encounter IDs
	SpotEncounter *e;
	for( SpotEncounterList::iterator iter = m_spotEncounterList.begin(); iter != m_spotEncounterList.end(); ++iter )
	{
		e = &(*iter);

		e->from.area = TheNavAreaGrid.GetNavAreaByID( e->from.id );
		if (e->from.area == NULL)
		{
			CONSOLE_ECHO( "ERROR: Corrupt navigation data. Missing \"from\" Navigation Area for Encounter Spot.\n" );
			error = NAV_CORRUPT_DATA;
		}

		e->to.area = TheNavAreaGrid.GetNavAreaByID( e->to.id );
		if (e->to.area == NULL)
		{
			CONSOLE_ECHO( "ERROR: Corrupt navigation data. Missing \"to\" Navigation Area for Encounter Spot.\n" );
			error = NAV_CORRUPT_DATA;
		}

		if (e->from.area && e->to.area)
		{
			// compute path
			float halfWidth;
			ComputePortal( e->to.area, e->toDir, &e->path.to, &halfWidth );
			ComputePortal( e->from.area, e->fromDir, &e->path.from, &halfWidth );

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

		// resolve HidingSpot IDs
		for( SpotOrderList::iterator oiter = e->spotList.begin(); oiter != e->spotList.end(); ++oiter )
		{
			SpotOrder *order = &(*oiter);

			order->spot = GetHidingSpotByID( order->id );
			if (order->spot == NULL)
			{
				CONSOLE_ECHO( "ERROR: Corrupt navigation data. Missing Hiding Spot\n" );
				error = NAV_CORRUPT_DATA;
			}
		}
	}

	// build overlap list
	/// @todo Optimize this
	for( NavAreaList::iterator oiter = TheNavAreaList.begin(); oiter != TheNavAreaList.end(); ++oiter )
	{
		CNavArea *area = *oiter;

		if (area == this)
			continue;

		if (IsOverlapping( area ))
			m_overlapList.push_back( area );
	}

	return error;
}


//--------------------------------------------------------------------------------------------------------------
/*
============
COM_FixSlashes

Changes all '/' characters into '\' characters, in place.
============
*/
inline void COM_FixSlashes( char *pname )
{
#ifdef _WIN32
	while ( *pname ) 
	{
		if ( *pname == '/' )
			*pname = '\\';
		pname++;
	}
#else
	while ( *pname ) 
	{
		if ( *pname == '\\' )
			*pname = '/';
		pname++;
	}
#endif
}

/**
 * Store AI navigation data to a file
 */
bool SaveNavigationMap( const char *filename )
{
	if (filename == NULL)
		return false;

	//
	// Store the NAV file
	//
	COM_FixSlashes( const_cast<char *>(filename) );

#ifdef WIN32
	int fd = _open( filename, _O_BINARY | _O_CREAT | _O_WRONLY, _S_IREAD | _S_IWRITE );
#else
#define _write write
	int fd = creat( filename, S_IRUSR | S_IWUSR | S_IRGRP );
#endif

	if (fd < 0)
		return false;

	// store "magic number" to help identify this kind of file
	unsigned int magic = NAV_MAGIC_NUMBER;
	_write( fd, &magic, sizeof(unsigned int) );

	// store version number of file
	// 1 = hiding spots as plain vector array
	// 2 = hiding spots as HidingSpot objects
	// 3 = Encounter spots use HidingSpot ID's instead of storing vector again
	// 4 = Includes size of source bsp file to verify nav data correlation
	// ---- Beta Release at V4 -----
	// 5 = Added Place info
	unsigned int version = 5;
	_write( fd, &version, sizeof(unsigned int) );


	// get size of source bsp file and store it in the nav file
	// so we can test if the bsp changed since the nav file was made
	char *bspFilename = GetBspFilename( filename );
	if (bspFilename == NULL)
		return false;

	unsigned int bspSize = (unsigned int)GET_FILE_SIZE( bspFilename );
	CONSOLE_ECHO( "Size of bsp file '%s' is %u bytes.\n", bspFilename, bspSize );

	_write( fd, &bspSize, sizeof(unsigned int) );


	//
	// Build a directory of the Places in this map
	//
	placeDirectory.Reset();

	NavAreaList::iterator it;
	for( it = TheNavAreaList.begin(); it != TheNavAreaList.end(); ++it )
	{
		CNavArea *area = *it;

		Place place = area->GetPlace();

		if (place)
		{
			placeDirectory.AddPlace( place );
		}
	}

	placeDirectory.Save( fd );


	//
	// Store navigation areas
	//

	// store number of areas
	unsigned int count = TheNavAreaList.size();
	_write( fd, &count, sizeof(unsigned int) );

	// store each area
	for( it = TheNavAreaList.begin(); it != TheNavAreaList.end(); ++it )
	{
		CNavArea *area = *it;

		area->Save( fd, version );
	}

	_close( fd );


#ifdef _WIN32
	// output a simple Wavefront file to visualize the generated areas in 3DSMax
	FILE *fp = fopen( "c:\\tmp\\nav.obj", "w" );
	if (fp)
	{
		for( NavAreaList::iterator iter = TheNavAreaList.begin(); iter != TheNavAreaList.end(); ++iter )
			(*iter)->Save( fp );

		fclose( fp );
	}
#endif


	return true;
}


//--------------------------------------------------------------------------------------------------------------
//
// Load place map
// This is legacy code - Places are stored directly in the nav file now
//
void LoadLocationFile( const char *filename )
{
	char locFilename[256];
	strcpy( locFilename, filename );

	char *dot = strchr( locFilename, '.' );
	if (dot)
	{
		strcpy( dot, ".loc" );

		int locDataLength;
		char *locDataFile = (char *)LOAD_FILE_FOR_ME( const_cast<char *>( locFilename ), &locDataLength );
		char *locData = locDataFile;

		if (locData)
		{
			CONSOLE_ECHO( "Loading legacy 'location file' '%s'\n", locFilename );

			// read directory
			locData = MP_COM_Parse( locData );
			int dirSize = atoi( MP_COM_GetToken() );

			if (dirSize)
			{
				std::vector<unsigned int> directory;

				directory.reserve( dirSize );

				for( int i=0; i<dirSize; ++i )
				{
					locData = MP_COM_Parse( locData );
					directory.push_back( TheBotPhrases->NameToID( MP_COM_GetToken() ) );
				}

				// read places for each nav area
				unsigned int areaID, locDirIndex;
				while(true)
				{
					locData = MP_COM_Parse( locData );
					if (locData == NULL)
						break;

					areaID = atoi( MP_COM_GetToken() );

					locData = MP_COM_Parse( locData );
					locDirIndex = atoi( MP_COM_GetToken() );

					CNavArea *area = TheNavAreaGrid.GetNavAreaByID( areaID );
					unsigned int place = (locDirIndex > 0) ? directory[ locDirIndex-1 ] : UNDEFINED_PLACE;
					
					if (area)
						area->SetPlace( place );
				}
			}

			FREE_FILE( locDataFile );
		}
	}
}


//--------------------------------------------------------------------------------------------------------------
/**
 * Performs a lightweight sanity-check of the specified map's nav mesh
 */
void SanityCheckNavigationMap( const char *mapName )
{
	if ( !mapName )
	{
		CONSOLE_ECHO( "ERROR: navigation file not specified.\n" );
		return;
	}

	// nav filename is derived from map filename
	const int BufLen = MAX_OSPATH;
	char bspFilename[MAX_OSPATH];
	char navFilename[MAX_OSPATH];
	snprintf( bspFilename, MAX_OSPATH, "maps\\%s.bsp", mapName );
	snprintf( navFilename, MAX_OSPATH, "maps\\%s.nav", mapName );

	SteamFile navFile( navFilename );

	if (!navFile.IsValid())
	{
		CONSOLE_ECHO( "ERROR: navigation file %s does not exist.\n", navFilename );
		return;
	}

	// check magic number
	bool result;
	unsigned int magic;
	result = navFile.Read( &magic, sizeof(unsigned int) );
	if (!result || magic != NAV_MAGIC_NUMBER)
	{
		CONSOLE_ECHO( "ERROR: Invalid navigation file '%s'.\n", navFilename );
		return;
	}

	// read file version number
	unsigned int version;
	result = navFile.Read( &version, sizeof(unsigned int) );
	if (!result || version > 5)
	{
		CONSOLE_ECHO( "ERROR: Unknown version in navigation file %s.\n", navFilename );
		return;
	}

	if (version >= 4)
	{
		// get size of source bsp file and verify that the bsp hasn't changed
		unsigned int saveBspSize;
		navFile.Read( &saveBspSize, sizeof(unsigned int) );

		// verify size
		if (bspFilename == NULL)
		{
			CONSOLE_ECHO( "ERROR: No map corresponds to navigation file %s.\n", navFilename );
			return;
		}

		unsigned int bspSize = (unsigned int)GET_FILE_SIZE( bspFilename );

		if (bspSize != saveBspSize)
		{
			// this nav file is out of date for this bsp file
			CONSOLE_ECHO( "ERROR: Out-of-date navigation data in navigation file %s.\n", navFilename );
			return;
		}
	}
	CONSOLE_ECHO( "navigation file %s passes the sanity check.\n", navFilename );
}

//--------------------------------------------------------------------------------------------------------------
/**
 * Load AI navigation data from a file
 */
NavErrorType LoadNavigationMap( void )
{
	// since the navigation map is destroyed on map change,
	// if it exists it has already been loaded for this map
	if (!TheNavAreaList.empty())
		return NAV_OK;

	// nav filename is derived from map filename
	char filename[256];
	sprintf( filename, "maps\\%s.nav", STRING( gpGlobals->mapname ) );


	// free previous navigation map data
	DestroyNavigationMap();
	placeDirectory.Reset();

	CNavArea::m_nextID = 1;

	SteamFile navFile( filename );

	if (!navFile.IsValid())
		return NAV_CANT_ACCESS_FILE;

	// check magic number
	bool result;
	unsigned int magic;
	result = navFile.Read( &magic, sizeof(unsigned int) );
	if (!result || magic != NAV_MAGIC_NUMBER)
	{
		CONSOLE_ECHO( "ERROR: Invalid navigation file '%s'.\n", filename );
		return NAV_INVALID_FILE;
	}

	// read file version number
	unsigned int version;
	result = navFile.Read( &version, sizeof(unsigned int) );
	if (!result || version > 5)
	{
		CONSOLE_ECHO( "ERROR: Unknown navigation file version.\n" );
		return NAV_BAD_FILE_VERSION;
	}

	if (version >= 4)
	{
		// get size of source bsp file and verify that the bsp hasn't changed
		unsigned int saveBspSize;
		navFile.Read( &saveBspSize, sizeof(unsigned int) );

		// verify size
		char *bspFilename = GetBspFilename( filename );
		if (bspFilename == NULL)
			return NAV_INVALID_FILE;

		unsigned int bspSize = (unsigned int)GET_FILE_SIZE( bspFilename );

		if (bspSize != saveBspSize)
		{
			// this nav file is out of date for this bsp file
			char *msg = "*** WARNING ***\nThe AI navigation data is from a different version of this map.\nThe CPU players will likely not perform well.\n";
			HintMessageToAllPlayers( msg );
			CONSOLE_ECHO( "\n-----------------\n" );
			CONSOLE_ECHO( msg );
			CONSOLE_ECHO( "-----------------\n\n" );
		}
	}

	// load Place directory
	if (version >= 5)
	{
		if ( !placeDirectory.Load( &navFile ) )
		{
			CONSOLE_ECHO( "ERROR: Invalid navigation file '%s'.\n", filename );
			return NAV_INVALID_FILE;
		}
	}

	// get number of areas
	unsigned int count;
	result = navFile.Read( &count, sizeof(unsigned int) );

	Extent extent;
	extent.lo.x = 9999999999.9f;
	extent.lo.y = 9999999999.9f;
	extent.hi.x = -9999999999.9f;
	extent.hi.y = -9999999999.9f;

	// load the areas and compute total extent
	for( unsigned int i=0; i<count; ++i )
	{
		CNavArea *area = new CNavArea;
		area->Load( &navFile, version );
		TheNavAreaList.push_back( area );

		const Extent *areaExtent = area->GetExtent();

		// check validity of nav area
		if (areaExtent->lo.x >= areaExtent->hi.x || areaExtent->lo.y >= areaExtent->hi.y)
			CONSOLE_ECHO( "WARNING: Degenerate Navigation Area #%d at ( %g, %g, %g )\n", 
											area->GetID(), area->m_center.x, area->m_center.y, area->m_center.z );

		if (areaExtent->lo.x < extent.lo.x)
			extent.lo.x = areaExtent->lo.x;
		if (areaExtent->lo.y < extent.lo.y)
			extent.lo.y = areaExtent->lo.y;
		if (areaExtent->hi.x > extent.hi.x)
			extent.hi.x = areaExtent->hi.x;
		if (areaExtent->hi.y > extent.hi.y)
			extent.hi.y = areaExtent->hi.y;
	}

	// add the areas to the grid
	TheNavAreaGrid.Initialize( extent.lo.x, extent.hi.x, extent.lo.y, extent.hi.y );

	NavAreaList::iterator iter;
	for( iter = TheNavAreaList.begin(); iter != TheNavAreaList.end(); ++iter )
		TheNavAreaGrid.AddNavArea( *iter );


	// allow areas to connect to each other, etc
	for( iter = TheNavAreaList.begin(); iter != TheNavAreaList.end(); ++iter )
	{
		CNavArea *area = *iter;
		area->PostLoad();
	}

	// load legacy location file (Places)
	if (version < 5)
	{
		LoadLocationFile( filename );
	}

	//
	// Set up all the ladders
	//
	BuildLadders();

	return NAV_OK;
}