/*
===========================================================================

Return to Castle Wolfenstein multiplayer GPL Source Code
Copyright (C) 1999-2010 id Software LLC, a ZeniMax Media company. 

This file is part of the Return to Castle Wolfenstein multiplayer GPL Source Code (RTCW MP Source Code).  

RTCW MP Source Code 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.

RTCW MP Source Code 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 RTCW MP Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the RTCW MP Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the RTCW MP Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

===========================================================================
*/


/*****************************************************************************
 * name:		be_aas_sample.c
 *
 * desc:		AAS environment sampling
 *
 *
 *****************************************************************************/

#include "../qcommon/q_shared.h"
#include "l_memory.h"
#include "l_script.h"
#include "l_precomp.h"
#include "l_struct.h"
#include "aasfile.h"
#include "botlib.h"
#include "be_aas.h"
#include "be_aas_funcs.h"
#include "be_aas_def.h"

extern botlib_import_t botimport;

//#define AAS_SAMPLE_DEBUG

#define BBOX_NORMAL_EPSILON     0.001

#define ON_EPSILON                  0 //0.0005

#define TRACEPLANE_EPSILON          0.125

typedef struct aas_tracestack_s
{
	vec3_t start;       //start point of the piece of line to trace
	vec3_t end;         //end point of the piece of line to trace
	int planenum;       //last plane used as splitter
	int nodenum;        //node found after splitting with planenum
} aas_tracestack_t;

//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void AAS_PresenceTypeBoundingBox( int presencetype, vec3_t mins, vec3_t maxs ) {
	int index;
	//bounding box size for each presence type
	vec3_t boxmins[3] = {{0, 0, 0}, {-15, -15, -24}, {-15, -15, -24}};
	vec3_t boxmaxs[3] = {{0, 0, 0}, { 15,  15,  32}, { 15,  15,   8}};

	if ( presencetype == PRESENCE_NORMAL ) {
		index = 1;
	} else if ( presencetype == PRESENCE_CROUCH ) {
		index = 2;
	} else
	{
		botimport.Print( PRT_FATAL, "AAS_PresenceTypeBoundingBox: unknown presence type\n" );
		index = 2;
	} //end if
	VectorCopy( boxmins[index], mins );
	VectorCopy( boxmaxs[index], maxs );
} //end of the function AAS_PresenceTypeBoundingBox
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void AAS_InitAASLinkHeap( void ) {
	int i, max_aaslinks;

	max_aaslinks = ( *aasworld ).linkheapsize;
	//if there's no link heap present
	if ( !( *aasworld ).linkheap ) {
		max_aaslinks = (int) 4096; //LibVarValue("max_aaslinks", "4096");
		if ( max_aaslinks < 0 ) {
			max_aaslinks = 0;
		}
		( *aasworld ).linkheapsize = max_aaslinks;
		( *aasworld ).linkheap = (aas_link_t *) GetHunkMemory( max_aaslinks * sizeof( aas_link_t ) );
	} //end if
	  //link the links on the heap
	( *aasworld ).linkheap[0].prev_ent = NULL;
	( *aasworld ).linkheap[0].next_ent = &( *aasworld ).linkheap[1];
	for ( i = 1; i < max_aaslinks - 1; i++ )
	{
		( *aasworld ).linkheap[i].prev_ent = &( *aasworld ).linkheap[i - 1];
		( *aasworld ).linkheap[i].next_ent = &( *aasworld ).linkheap[i + 1];
	} //end for
	( *aasworld ).linkheap[max_aaslinks - 1].prev_ent = &( *aasworld ).linkheap[max_aaslinks - 2];
	( *aasworld ).linkheap[max_aaslinks - 1].next_ent = NULL;
	//pointer to the first free link
	( *aasworld ).freelinks = &( *aasworld ).linkheap[0];
} //end of the function AAS_InitAASLinkHeap
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void AAS_FreeAASLinkHeap( void ) {
	if ( ( *aasworld ).linkheap ) {
		FreeMemory( ( *aasworld ).linkheap );
	}
	( *aasworld ).linkheap = NULL;
	( *aasworld ).linkheapsize = 0;
} //end of the function AAS_FreeAASLinkHeap
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
aas_link_t *AAS_AllocAASLink( void ) {
	aas_link_t *link;

	link = ( *aasworld ).freelinks;
	if ( !link ) {
		botimport.Print( PRT_FATAL, "empty aas link heap\n" );
		return NULL;
	} //end if
	if ( ( *aasworld ).freelinks ) {
		( *aasworld ).freelinks = ( *aasworld ).freelinks->next_ent;
	}
	if ( ( *aasworld ).freelinks ) {
		( *aasworld ).freelinks->prev_ent = NULL;
	}
	return link;
} //end of the function AAS_AllocAASLink
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void AAS_DeAllocAASLink( aas_link_t *link ) {
	if ( ( *aasworld ).freelinks ) {
		( *aasworld ).freelinks->prev_ent = link;
	}
	link->prev_ent = NULL;
	link->next_ent = ( *aasworld ).freelinks;
	link->prev_area = NULL;
	link->next_area = NULL;
	( *aasworld ).freelinks = link;
} //end of the function AAS_DeAllocAASLink
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void AAS_InitAASLinkedEntities( void ) {
	if ( !( *aasworld ).loaded ) {
		return;
	}
	if ( ( *aasworld ).arealinkedentities ) {
		FreeMemory( ( *aasworld ).arealinkedentities );
	}
	( *aasworld ).arealinkedentities = (aas_link_t **) GetClearedHunkMemory(
		( *aasworld ).numareas * sizeof( aas_link_t * ) );
} //end of the function AAS_InitAASLinkedEntities
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void AAS_FreeAASLinkedEntities( void ) {
	if ( ( *aasworld ).arealinkedentities ) {
		FreeMemory( ( *aasworld ).arealinkedentities );
	}
	( *aasworld ).arealinkedentities = NULL;
} //end of the function AAS_InitAASLinkedEntities
//===========================================================================
// returns the AAS area the point is in
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
int AAS_PointAreaNum( vec3_t point ) {
	int nodenum;
	vec_t dist;
	aas_node_t *node;
	aas_plane_t *plane;

	if ( !( *aasworld ).loaded ) {
		botimport.Print( PRT_ERROR, "AAS_PointAreaNum: aas not loaded\n" );
		return 0;
	} //end if

	//start with node 1 because node zero is a dummy used for solid leafs
	nodenum = 1;
	while ( nodenum > 0 )
	{
//		botimport.Print(PRT_MESSAGE, "[%d]", nodenum);
#ifdef AAS_SAMPLE_DEBUG
		if ( nodenum >= ( *aasworld ).numnodes ) {
			botimport.Print( PRT_ERROR, "nodenum = %d >= (*aasworld).numnodes = %d\n", nodenum, ( *aasworld ).numnodes );
			return 0;
		} //end if
#endif //AAS_SAMPLE_DEBUG
		node = &( *aasworld ).nodes[nodenum];
#ifdef AAS_SAMPLE_DEBUG
		if ( node->planenum < 0 || node->planenum >= ( *aasworld ).numplanes ) {
			botimport.Print( PRT_ERROR, "node->planenum = %d >= (*aasworld).numplanes = %d\n", node->planenum, ( *aasworld ).numplanes );
			return 0;
		} //end if
#endif //AAS_SAMPLE_DEBUG
		plane = &( *aasworld ).planes[node->planenum];
		dist = DotProduct( point, plane->normal ) - plane->dist;
		if ( dist > 0 ) {
			nodenum = node->children[0];
		} else { nodenum = node->children[1];}
	} //end while
	if ( !nodenum ) {
#ifdef AAS_SAMPLE_DEBUG
		botimport.Print( PRT_MESSAGE, "in solid\n" );
#endif //AAS_SAMPLE_DEBUG
		return 0;
	} //end if
	return -nodenum;
} //end of the function AAS_PointAreaNum
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
int AAS_AreaCluster( int areanum ) {
	if ( areanum <= 0 || areanum >= ( *aasworld ).numareas ) {
		botimport.Print( PRT_ERROR, "AAS_AreaCluster: invalid area number\n" );
		return 0;
	} //end if
	return ( *aasworld ).areasettings[areanum].cluster;
} //end of the function AAS_AreaCluster
//===========================================================================
// returns the presence types of the given area
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
int AAS_AreaPresenceType( int areanum ) {
	if ( !( *aasworld ).loaded ) {
		return 0;
	}
	if ( areanum <= 0 || areanum >= ( *aasworld ).numareas ) {
		botimport.Print( PRT_ERROR, "AAS_AreaPresenceType: invalid area number\n" );
		return 0;
	} //end if
	return ( *aasworld ).areasettings[areanum].presencetype;
} //end of the function AAS_AreaPresenceType
//===========================================================================
// returns the presence type at the given point
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
int AAS_PointPresenceType( vec3_t point ) {
	int areanum;

	if ( !( *aasworld ).loaded ) {
		return 0;
	}

	areanum = AAS_PointAreaNum( point );
	if ( !areanum ) {
		return PRESENCE_NONE;
	}
	return ( *aasworld ).areasettings[areanum].presencetype;
} //end of the function AAS_PointPresenceType
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
qboolean AAS_AreaEntityCollision( int areanum, vec3_t start, vec3_t end,
								  int presencetype, int passent, aas_trace_t *trace ) {
	int collision;
	vec3_t boxmins, boxmaxs;
	aas_link_t *link;
	bsp_trace_t bsptrace;

	AAS_PresenceTypeBoundingBox( presencetype, boxmins, boxmaxs );

	memset( &bsptrace, 0, sizeof( bsp_trace_t ) ); //make compiler happy
	//assume no collision
	bsptrace.fraction = 1;
	collision = qfalse;
	for ( link = ( *aasworld ).arealinkedentities[areanum]; link; link = link->next_ent )
	{
		//ignore the pass entity
		if ( link->entnum == passent ) {
			continue;
		}
		//
		if ( AAS_EntityCollision( link->entnum, start, boxmins, boxmaxs, end,
								  CONTENTS_SOLID | CONTENTS_PLAYERCLIP, &bsptrace ) ) {
			collision = qtrue;
		} //end if
	} //end for
	if ( collision ) {
		trace->startsolid = bsptrace.startsolid;
		trace->ent = bsptrace.ent;
		VectorCopy( bsptrace.endpos, trace->endpos );
		trace->area = 0;
		trace->planenum = 0;
		return qtrue;
	} //end if
	return qfalse;
} //end of the function AAS_AreaEntityCollision
//===========================================================================
// recursive subdivision of the line by the BSP tree.
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
aas_trace_t AAS_TraceClientBBox( vec3_t start, vec3_t end, int presencetype,
								 int passent ) {
	int side, nodenum, tmpplanenum;
	float front, back, frac;
	vec3_t cur_start, cur_end, cur_mid, v1, v2;
	aas_tracestack_t tracestack[127];
	aas_tracestack_t *tstack_p;
	aas_node_t *aasnode;
	aas_plane_t *plane;
	aas_trace_t trace;

	//clear the trace structure
	memset( &trace, 0, sizeof( aas_trace_t ) );

	if ( !( *aasworld ).loaded ) {
		return trace;
	}

	tstack_p = tracestack;
	//we start with the whole line on the stack
	VectorCopy( start, tstack_p->start );
	VectorCopy( end, tstack_p->end );
	tstack_p->planenum = 0;
	//start with node 1 because node zero is a dummy for a solid leaf
	tstack_p->nodenum = 1;      //starting at the root of the tree
	tstack_p++;

	while ( 1 )
	{
		//pop up the stack
		tstack_p--;
		//if the trace stack is empty (ended up with a piece of the
		//line to be traced in an area)
		if ( tstack_p < tracestack ) {
			tstack_p++;
			//nothing was hit
			trace.startsolid = qfalse;
			trace.fraction = 1.0;
			//endpos is the end of the line
			VectorCopy( end, trace.endpos );
			//nothing hit
			trace.ent = 0;
			trace.area = 0;
			trace.planenum = 0;
			return trace;
		} //end if
		  //number of the current node to test the line against
		nodenum = tstack_p->nodenum;
		//if it is an area
		if ( nodenum < 0 ) {
#ifdef AAS_SAMPLE_DEBUG
			if ( -nodenum > ( *aasworld ).numareasettings ) {
				botimport.Print( PRT_ERROR, "AAS_TraceBoundingBox: -nodenum out of range\n" );
				return trace;
			} //end if
#endif //AAS_SAMPLE_DEBUG
			//botimport.Print(PRT_MESSAGE, "areanum = %d, must be %d\n", -nodenum, AAS_PointAreaNum(start));
			//if can't enter the area because it hasn't got the right presence type
			if ( !( ( *aasworld ).areasettings[-nodenum].presencetype & presencetype ) ) {
				//if the start point is still the initial start point
				//NOTE: no need for epsilons because the points will be
				//exactly the same when they're both the start point
				if ( tstack_p->start[0] == start[0] &&
					 tstack_p->start[1] == start[1] &&
					 tstack_p->start[2] == start[2] )
				{
					trace.startsolid = qtrue;
					trace.fraction = 0.0;
					VectorClear(v1);
				} //end if
				else
				{
					trace.startsolid = qfalse;
					VectorSubtract( end, start, v1 );
					VectorSubtract( tstack_p->start, start, v2 );
					trace.fraction = VectorLength( v2 ) / VectorNormalize( v1 );
					VectorMA( tstack_p->start, -0.125, v1, tstack_p->start );
				} //end else
				VectorCopy( tstack_p->start, trace.endpos );
				trace.ent = 0;
				trace.area = -nodenum;
//				VectorSubtract(end, start, v1);
				trace.planenum = tstack_p->planenum;
				//always take the plane with normal facing towards the trace start
				plane = &( *aasworld ).planes[trace.planenum];
				if ( DotProduct( v1, plane->normal ) > 0 ) {
					trace.planenum ^= 1;
				}
				return trace;
			} //end if
			else
			{
				if ( passent >= 0 ) {
					if ( AAS_AreaEntityCollision( -nodenum, tstack_p->start,
												  tstack_p->end, presencetype, passent,
												  &trace ) ) {
						if ( !trace.startsolid ) {
							VectorSubtract( end, start, v1 );
							VectorSubtract( trace.endpos, start, v2 );
							trace.fraction = VectorLength( v2 ) / VectorLength( v1 );
						} //end if
						return trace;
					} //end if
				} //end if
			} //end else
			trace.lastarea = -nodenum;
			continue;
		} //end if
		  //if it is a solid leaf
		if ( !nodenum ) {
			//if the start point is still the initial start point
			//NOTE: no need for epsilons because the points will be
			//exactly the same when they're both the start point
			if ( tstack_p->start[0] == start[0] &&
				 tstack_p->start[1] == start[1] &&
				 tstack_p->start[2] == start[2] )
			{
				trace.startsolid = qtrue;
				trace.fraction = 0.0;
				VectorClear(v1);
			} //end if
			else
			{
				trace.startsolid = qfalse;
				VectorSubtract( end, start, v1 );
				VectorSubtract( tstack_p->start, start, v2 );
				trace.fraction = VectorLength( v2 ) / VectorNormalize( v1 );
				VectorMA( tstack_p->start, -0.125, v1, tstack_p->start );
			} //end else
			VectorCopy( tstack_p->start, trace.endpos );
			trace.ent = 0;
			trace.area = 0; //hit solid leaf
//			VectorSubtract(end, start, v1);
			trace.planenum = tstack_p->planenum;
			//always take the plane with normal facing towards the trace start
			plane = &( *aasworld ).planes[trace.planenum];
			if ( DotProduct( v1, plane->normal ) > 0 ) {
				trace.planenum ^= 1;
			}
			return trace;
		} //end if
#ifdef AAS_SAMPLE_DEBUG
		if ( nodenum > ( *aasworld ).numnodes ) {
			botimport.Print( PRT_ERROR, "AAS_TraceBoundingBox: nodenum out of range\n" );
			return trace;
		} //end if
#endif //AAS_SAMPLE_DEBUG
	   //the node to test against
		aasnode = &( *aasworld ).nodes[nodenum];
		//start point of current line to test against node
		VectorCopy( tstack_p->start, cur_start );
		//end point of the current line to test against node
		VectorCopy( tstack_p->end, cur_end );
		//the current node plane
		plane = &( *aasworld ).planes[aasnode->planenum];

		switch ( plane->type )
		{/*FIXME: wtf doesn't this work? obviously the axial node planes aren't always facing positive!!!
			//check for axial planes
			case PLANE_X:
			{
				front = cur_start[0] - plane->dist;
				back = cur_end[0] - plane->dist;
				break;
			} //end case
			case PLANE_Y:
			{
				front = cur_start[1] - plane->dist;
				back = cur_end[1] - plane->dist;
				break;
			} //end case
			case PLANE_Z:
			{
				front = cur_start[2] - plane->dist;
				back = cur_end[2] - plane->dist;
				break;
			} //end case*/
		default:     //gee it's not an axial plane
		{
			front = DotProduct( cur_start, plane->normal ) - plane->dist;
			back = DotProduct( cur_end, plane->normal ) - plane->dist;
			break;
		}     //end default
		} //end switch

		//calculate the hitpoint with the node (split point of the line)
		//put the crosspoint TRACEPLANE_EPSILON pixels on the near side
		if ( front < 0 ) {
			frac = ( front + TRACEPLANE_EPSILON ) / ( front - back );
		} else { frac = ( front - TRACEPLANE_EPSILON ) / ( front - back );}
		//if the whole to be traced line is totally at the front of this node
		//only go down the tree with the front child
		if ( ( front >= -ON_EPSILON && back >= -ON_EPSILON ) ) {
			//keep the current start and end point on the stack
			//and go down the tree with the front child
			tstack_p->nodenum = aasnode->children[0];
			tstack_p++;
			if ( tstack_p >= &tracestack[127] ) {
				botimport.Print( PRT_ERROR, "AAS_TraceBoundingBox: stack overflow\n" );
				return trace;
			} //end if
		} //end if
		  //if the whole to be traced line is totally at the back of this node
		  //only go down the tree with the back child
		else if ( ( front < ON_EPSILON && back < ON_EPSILON ) ) {
			//keep the current start and end point on the stack
			//and go down the tree with the back child
			tstack_p->nodenum = aasnode->children[1];
			tstack_p++;
			if ( tstack_p >= &tracestack[127] ) {
				botimport.Print( PRT_ERROR, "AAS_TraceBoundingBox: stack overflow\n" );
				return trace;
			} //end if
		} //end if
		  //go down the tree both at the front and back of the node
		else
		{
			tmpplanenum = tstack_p->planenum;
			//
			if ( frac < 0 ) {
				frac = 0.001; //0
			} else if ( frac > 1 )                         {
				frac = 0.999; //1
			}
			//frac = front / (front-back);
			//
			cur_mid[0] = cur_start[0] + ( cur_end[0] - cur_start[0] ) * frac;
			cur_mid[1] = cur_start[1] + ( cur_end[1] - cur_start[1] ) * frac;
			cur_mid[2] = cur_start[2] + ( cur_end[2] - cur_start[2] ) * frac;

//			AAS_DrawPlaneCross(cur_mid, plane->normal, plane->dist, plane->type, LINECOLOR_RED);
			//side the front part of the line is on
			side = front < 0;
			//first put the end part of the line on the stack (back side)
			VectorCopy( cur_mid, tstack_p->start );
			//not necesary to store because still on stack
			//VectorCopy(cur_end, tstack_p->end);
			tstack_p->planenum = aasnode->planenum;
			tstack_p->nodenum = aasnode->children[!side];
			tstack_p++;
			if ( tstack_p >= &tracestack[127] ) {
				botimport.Print( PRT_ERROR, "AAS_TraceBoundingBox: stack overflow\n" );
				return trace;
			} //end if
			  //now put the part near the start of the line on the stack so we will
			  //continue with thats part first. This way we'll find the first
			  //hit of the bbox
			VectorCopy( cur_start, tstack_p->start );
			VectorCopy( cur_mid, tstack_p->end );
			tstack_p->planenum = tmpplanenum;
			tstack_p->nodenum = aasnode->children[side];
			tstack_p++;
			if ( tstack_p >= &tracestack[127] ) {
				botimport.Print( PRT_ERROR, "AAS_TraceBoundingBox: stack overflow\n" );
				return trace;
			} //end if
		} //end else
	} //end while
//	return trace;
} //end of the function AAS_TraceClientBBox
//===========================================================================
// recursive subdivision of the line by the BSP tree.
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
int AAS_TraceAreas( vec3_t start, vec3_t end, int *areas, vec3_t *points, int maxareas ) {
	int side, nodenum, tmpplanenum;
	int numareas;
	float front, back, frac;
	vec3_t cur_start, cur_end, cur_mid;
	aas_tracestack_t tracestack[127];
	aas_tracestack_t *tstack_p;
	aas_node_t *aasnode;
	aas_plane_t *plane;

	numareas = 0;
	areas[0] = 0;
	if ( !( *aasworld ).loaded ) {
		return numareas;
	}

	tstack_p = tracestack;
	//we start with the whole line on the stack
	VectorCopy( start, tstack_p->start );
	VectorCopy( end, tstack_p->end );
	tstack_p->planenum = 0;
	//start with node 1 because node zero is a dummy for a solid leaf
	tstack_p->nodenum = 1;      //starting at the root of the tree
	tstack_p++;

	while ( 1 )
	{
		//pop up the stack
		tstack_p--;
		//if the trace stack is empty (ended up with a piece of the
		//line to be traced in an area)
		if ( tstack_p < tracestack ) {
			return numareas;
		} //end if
		  //number of the current node to test the line against
		nodenum = tstack_p->nodenum;
		//if it is an area
		if ( nodenum < 0 ) {
#ifdef AAS_SAMPLE_DEBUG
			if ( -nodenum > ( *aasworld ).numareasettings ) {
				botimport.Print( PRT_ERROR, "AAS_TraceAreas: -nodenum = %d out of range\n", -nodenum );
				return numareas;
			} //end if
#endif //AAS_SAMPLE_DEBUG
			//botimport.Print(PRT_MESSAGE, "areanum = %d, must be %d\n", -nodenum, AAS_PointAreaNum(start));
			areas[numareas] = -nodenum;
			if ( points ) {
				VectorCopy( tstack_p->start, points[numareas] );
			}
			numareas++;
			if ( numareas >= maxareas ) {
				return numareas;
			}
			continue;
		} //end if
		  //if it is a solid leaf
		if ( !nodenum ) {
			continue;
		} //end if
#ifdef AAS_SAMPLE_DEBUG
		if ( nodenum > ( *aasworld ).numnodes ) {
			botimport.Print( PRT_ERROR, "AAS_TraceAreas: nodenum out of range\n" );
			return numareas;
		} //end if
#endif //AAS_SAMPLE_DEBUG
	   //the node to test against
		aasnode = &( *aasworld ).nodes[nodenum];
		//start point of current line to test against node
		VectorCopy( tstack_p->start, cur_start );
		//end point of the current line to test against node
		VectorCopy( tstack_p->end, cur_end );
		//the current node plane
		plane = &( *aasworld ).planes[aasnode->planenum];

		switch ( plane->type )
		{/*FIXME: wtf doesn't this work? obviously the node planes aren't always facing positive!!!
			//check for axial planes
			case PLANE_X:
			{
				front = cur_start[0] - plane->dist;
				back = cur_end[0] - plane->dist;
				break;
			} //end case
			case PLANE_Y:
			{
				front = cur_start[1] - plane->dist;
				back = cur_end[1] - plane->dist;
				break;
			} //end case
			case PLANE_Z:
			{
				front = cur_start[2] - plane->dist;
				back = cur_end[2] - plane->dist;
				break;
			} //end case*/
		default:     //gee it's not an axial plane
		{
			front = DotProduct( cur_start, plane->normal ) - plane->dist;
			back = DotProduct( cur_end, plane->normal ) - plane->dist;
			break;
		}     //end default
		} //end switch

		//if the whole to be traced line is totally at the front of this node
		//only go down the tree with the front child
		if ( front > 0 && back > 0 ) {
			//keep the current start and end point on the stack
			//and go down the tree with the front child
			tstack_p->nodenum = aasnode->children[0];
			tstack_p++;
			if ( tstack_p >= &tracestack[127] ) {
				botimport.Print( PRT_ERROR, "AAS_TraceAreas: stack overflow\n" );
				return numareas;
			} //end if
		} //end if
		  //if the whole to be traced line is totally at the back of this node
		  //only go down the tree with the back child
		else if ( front <= 0 && back <= 0 ) {
			//keep the current start and end point on the stack
			//and go down the tree with the back child
			tstack_p->nodenum = aasnode->children[1];
			tstack_p++;
			if ( tstack_p >= &tracestack[127] ) {
				botimport.Print( PRT_ERROR, "AAS_TraceAreas: stack overflow\n" );
				return numareas;
			} //end if
		} //end if
		  //go down the tree both at the front and back of the node
		else
		{
			tmpplanenum = tstack_p->planenum;
			//calculate the hitpoint with the node (split point of the line)
			//put the crosspoint TRACEPLANE_EPSILON pixels on the near side
			if ( front < 0 ) {
				frac = ( front ) / ( front - back );
			} else { frac = ( front ) / ( front - back );}
			if ( frac < 0 ) {
				frac = 0;
			} else if ( frac > 1 ) {
				frac = 1;
			}
			//frac = front / (front-back);
			//
			cur_mid[0] = cur_start[0] + ( cur_end[0] - cur_start[0] ) * frac;
			cur_mid[1] = cur_start[1] + ( cur_end[1] - cur_start[1] ) * frac;
			cur_mid[2] = cur_start[2] + ( cur_end[2] - cur_start[2] ) * frac;

//			AAS_DrawPlaneCross(cur_mid, plane->normal, plane->dist, plane->type, LINECOLOR_RED);
			//side the front part of the line is on
			side = front < 0;
			//first put the end part of the line on the stack (back side)
			VectorCopy( cur_mid, tstack_p->start );
			//not necesary to store because still on stack
			//VectorCopy(cur_end, tstack_p->end);
			tstack_p->planenum = aasnode->planenum;
			tstack_p->nodenum = aasnode->children[!side];
			tstack_p++;
			if ( tstack_p >= &tracestack[127] ) {
				botimport.Print( PRT_ERROR, "AAS_TraceAreas: stack overflow\n" );
				return numareas;
			} //end if
			  //now put the part near the start of the line on the stack so we will
			  //continue with thats part first. This way we'll find the first
			  //hit of the bbox
			VectorCopy( cur_start, tstack_p->start );
			VectorCopy( cur_mid, tstack_p->end );
			tstack_p->planenum = tmpplanenum;
			tstack_p->nodenum = aasnode->children[side];
			tstack_p++;
			if ( tstack_p >= &tracestack[127] ) {
				botimport.Print( PRT_ERROR, "AAS_TraceAreas: stack overflow\n" );
				return numareas;
			} //end if
		} //end else
	} //end while
//	return numareas;
} //end of the function AAS_TraceAreas
//===========================================================================
// a simple cross product
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
// void AAS_OrthogonalToVectors(vec3_t v1, vec3_t v2, vec3_t res)
#define AAS_OrthogonalToVectors( v1, v2, res ) \
	( res )[0] = ( ( v1 )[1] * ( v2 )[2] ) - ( ( v1 )[2] * ( v2 )[1] );	\
	( res )[1] = ( ( v1 )[2] * ( v2 )[0] ) - ( ( v1 )[0] * ( v2 )[2] );	\
	( res )[2] = ( ( v1 )[0] * ( v2 )[1] ) - ( ( v1 )[1] * ( v2 )[0] );
//===========================================================================
// tests if the given point is within the face boundaries
//
// Parameter:				face		: face to test if the point is in it
//								pnormal	: normal of the plane to use for the face
//								point		: point to test if inside face boundaries
// Returns:					qtrue if the point is within the face boundaries
// Changes Globals:		-
//===========================================================================
qboolean AAS_InsideFace( aas_face_t *face, vec3_t pnormal, vec3_t point, float epsilon ) {
	int i, firstvertex, edgenum;
	vec3_t v0;
	vec3_t edgevec, pointvec, sepnormal;
	aas_edge_t *edge;
#ifdef AAS_SAMPLE_DEBUG
	int lastvertex = 0;
#endif //AAS_SAMPLE_DEBUG

	if ( !( *aasworld ).loaded ) {
		return qfalse;
	}

	for ( i = 0; i < face->numedges; i++ )
	{
		edgenum = ( *aasworld ).edgeindex[face->firstedge + i];
		edge = &( *aasworld ).edges[abs( edgenum )];
		//get the first vertex of the edge
		firstvertex = edgenum < 0;
		VectorCopy( ( *aasworld ).vertexes[edge->v[firstvertex]], v0 );
		//edge vector
		VectorSubtract( ( *aasworld ).vertexes[edge->v[!firstvertex]], v0, edgevec );
		//
#ifdef AAS_SAMPLE_DEBUG
		if ( lastvertex && lastvertex != edge->v[firstvertex] ) {
			botimport.Print( PRT_MESSAGE, "winding not counter clockwise\n" );
		} //end if
		lastvertex = edge->v[!firstvertex];
#endif //AAS_SAMPLE_DEBUG
	   //vector from first edge point to point possible in face
		VectorSubtract( point, v0, pointvec );
		//get a vector pointing inside the face orthogonal to both the
		//edge vector and the normal vector of the plane the face is in
		//this vector defines a plane through the origin (first vertex of
		//edge) and through both the edge vector and the normal vector
		//of the plane
		AAS_OrthogonalToVectors( edgevec, pnormal, sepnormal );
		//check on wich side of the above plane the point is
		//this is done by checking the sign of the dot product of the
		//vector orthogonal vector from above and the vector from the
		//origin (first vertex of edge) to the point
		//if the dotproduct is smaller than zero the point is outside the face
		if ( DotProduct( pointvec, sepnormal ) < -epsilon ) {
			return qfalse;
		}
	} //end for
	return qtrue;
} //end of the function AAS_InsideFace
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
qboolean AAS_PointInsideFace( int facenum, vec3_t point, float epsilon ) {
	int i, firstvertex, edgenum;
	vec_t *v1, *v2;
	vec3_t edgevec, pointvec, sepnormal;
	aas_edge_t *edge;
	aas_plane_t *plane;
	aas_face_t *face;

	if ( !( *aasworld ).loaded ) {
		return qfalse;
	}

	face = &( *aasworld ).faces[facenum];
	plane = &( *aasworld ).planes[face->planenum];
	//
	for ( i = 0; i < face->numedges; i++ )
	{
		edgenum = ( *aasworld ).edgeindex[face->firstedge + i];
		edge = &( *aasworld ).edges[abs( edgenum )];
		//get the first vertex of the edge
		firstvertex = edgenum < 0;
		v1 = ( *aasworld ).vertexes[edge->v[firstvertex]];
		v2 = ( *aasworld ).vertexes[edge->v[!firstvertex]];
		//edge vector
		VectorSubtract( v2, v1, edgevec );
		//vector from first edge point to point possible in face
		VectorSubtract( point, v1, pointvec );
		//
		CrossProduct( edgevec, plane->normal, sepnormal );
		//
		if ( DotProduct( pointvec, sepnormal ) < -epsilon ) {
			return qfalse;
		}
	} //end for
	return qtrue;
} //end of the function AAS_PointInsideFace
//===========================================================================
// returns the ground face the given point is above in the given area
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
aas_face_t *AAS_AreaGroundFace( int areanum, vec3_t point ) {
	int i, facenum;
	vec3_t up = {0, 0, 1};
	vec3_t normal;
	aas_area_t *area;
	aas_face_t *face;

	if ( !( *aasworld ).loaded ) {
		return NULL;
	}

	area = &( *aasworld ).areas[areanum];
	for ( i = 0; i < area->numfaces; i++ )
	{
		facenum = ( *aasworld ).faceindex[area->firstface + i];
		face = &( *aasworld ).faces[abs( facenum )];
		//if this is a ground face
		if ( face->faceflags & FACE_GROUND ) {
			//get the up or down normal
			if ( ( *aasworld ).planes[face->planenum].normal[2] < 0 ) {
				VectorNegate( up, normal );
			} else { VectorCopy( up, normal );}
			//check if the point is in the face
			if ( AAS_InsideFace( face, normal, point, 0.01 ) ) {
				return face;
			}
		} //end if
	} //end for
	return NULL;
} //end of the function AAS_AreaGroundFace
//===========================================================================
// returns the face the trace end position is situated in
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void AAS_FacePlane( int facenum, vec3_t normal, float *dist ) {
	aas_plane_t *plane;

	plane = &( *aasworld ).planes[( *aasworld ).faces[facenum].planenum];
	VectorCopy( plane->normal, normal );
	*dist = plane->dist;
} //end of the function AAS_FacePlane
//===========================================================================
// returns the face the trace end position is situated in
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
aas_face_t *AAS_TraceEndFace( aas_trace_t *trace ) {
	int i, facenum;
	aas_area_t *area;
	aas_face_t *face, *firstface = NULL;

	if ( !( *aasworld ).loaded ) {
		return NULL;
	}

	//if started in solid no face was hit
	if ( trace->startsolid ) {
		return NULL;
	}
	//trace->lastarea is the last area the trace was in
	area = &( *aasworld ).areas[trace->lastarea];
	//check which face the trace.endpos was in
	for ( i = 0; i < area->numfaces; i++ )
	{
		facenum = ( *aasworld ).faceindex[area->firstface + i];
		face = &( *aasworld ).faces[abs( facenum )];
		//if the face is in the same plane as the trace end point
		if ( ( face->planenum & ~1 ) == ( trace->planenum & ~1 ) ) {
			//firstface is used for optimization, if theres only one
			//face in the plane then it has to be the good one
			//if there are more faces in the same plane then always
			//check the one with the fewest edges first
/*			if (firstface)
			{
				if (firstface->numedges < face->numedges)
				{
					if (AAS_InsideFace(firstface,
						(*aasworld).planes[face->planenum].normal, trace->endpos))
					{
						return firstface;
					} //end if
					firstface = face;
				} //end if
				else
				{
					if (AAS_InsideFace(face,
						(*aasworld).planes[face->planenum].normal, trace->endpos))
					{
						return face;
					} //end if
				} //end else
			} //end if
			else
			{
				firstface = face;
			} //end else*/
			if ( AAS_InsideFace( face,
								 ( *aasworld ).planes[face->planenum].normal, trace->endpos, 0.01 ) ) {
				return face;
			}
		} //end if
	} //end for
	return firstface;
} //end of the function AAS_TraceEndFace
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
int AAS_BoxOnPlaneSide2( vec3_t absmins, vec3_t absmaxs, aas_plane_t *p ) {
	int i, sides;
	float dist1, dist2;
	vec3_t corners[2];

	for ( i = 0; i < 3; i++ )
	{
		if ( p->normal[i] < 0 ) {
			corners[0][i] = absmins[i];
			corners[1][i] = absmaxs[i];
		} //end if
		else
		{
			corners[1][i] = absmins[i];
			corners[0][i] = absmaxs[i];
		} //end else
	} //end for
	dist1 = DotProduct( p->normal, corners[0] ) - p->dist;
	dist2 = DotProduct( p->normal, corners[1] ) - p->dist;
	sides = 0;
	if ( dist1 >= 0 ) {
		sides = 1;
	}
	if ( dist2 < 0 ) {
		sides |= 2;
	}

	return sides;
} //end of the function AAS_BoxOnPlaneSide2
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
//int AAS_BoxOnPlaneSide(vec3_t absmins, vec3_t absmaxs, aas_plane_t *p)
#define AAS_BoxOnPlaneSide( absmins, absmaxs, p ) (	\
		( ( p )->type < 3 ) ? \
		( \
			( ( p )->dist <= ( absmins )[( p )->type] ) ? \
			( \
				1 \
			) \
			: \
			( \
				( ( p )->dist >= ( absmaxs )[( p )->type] ) ? \
				( \
					2 \
				) \
				: \
				( \
					3 \
				) \
			) \
		) \
		: \
		( \
			AAS_BoxOnPlaneSide2( ( absmins ), ( absmaxs ), ( p ) ) \
		) \
		) //end of the function AAS_BoxOnPlaneSide
//===========================================================================
// remove the links to this entity from all areas
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void AAS_UnlinkFromAreas( aas_link_t *areas ) {
	aas_link_t *link, *nextlink;

	for ( link = areas; link; link = nextlink )
	{
		//next area the entity is linked in
		nextlink = link->next_area;
		//remove the entity from the linked list of this area
		if ( link->prev_ent ) {
			link->prev_ent->next_ent = link->next_ent;
		} else { ( *aasworld ).arealinkedentities[link->areanum] = link->next_ent;}
		if ( link->next_ent ) {
			link->next_ent->prev_ent = link->prev_ent;
		}
		//deallocate the link structure
		AAS_DeAllocAASLink( link );
	} //end for
} //end of the function AAS_UnlinkFromAreas
//===========================================================================
// link the entity to the areas the bounding box is totally or partly
// situated in. This is done with recursion down the tree using the
// bounding box to test for plane sides
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================

typedef struct
{
	int nodenum;        //node found after splitting
} aas_linkstack_t;

aas_link_t *AAS_AASLinkEntity( vec3_t absmins, vec3_t absmaxs, int entnum ) {
	int side, nodenum;
	aas_linkstack_t linkstack[128];
	aas_linkstack_t *lstack_p;
	aas_node_t *aasnode;
	aas_plane_t *plane;
	aas_link_t *link, *areas;

	if ( !( *aasworld ).loaded ) {
		botimport.Print( PRT_ERROR, "AAS_LinkEntity: aas not loaded\n" );
		return NULL;
	} //end if

	areas = NULL;
	//
	lstack_p = linkstack;
	//we start with the whole line on the stack
	//start with node 1 because node zero is a dummy used for solid leafs
	lstack_p->nodenum = 1;      //starting at the root of the tree
	lstack_p++;

	while ( 1 )
	{
		//pop up the stack
		lstack_p--;
		//if the trace stack is empty (ended up with a piece of the
		//line to be traced in an area)
		if ( lstack_p < linkstack ) {
			break;
		}
		//number of the current node to test the line against
		nodenum = lstack_p->nodenum;
		//if it is an area
		if ( nodenum < 0 ) {
			//NOTE: the entity might have already been linked into this area
			// because several node children can point to the same area
			for ( link = ( *aasworld ).arealinkedentities[-nodenum]; link; link = link->next_ent )
			{
				if ( link->entnum == entnum ) {
					break;
				}
			} //end for
			if ( link ) {
				continue;
			}
			//
			link = AAS_AllocAASLink();
			if ( !link ) {
				return areas;
			}
			link->entnum = entnum;
			link->areanum = -nodenum;
			//put the link into the double linked area list of the entity
			link->prev_area = NULL;
			link->next_area = areas;
			if ( areas ) {
				areas->prev_area = link;
			}
			areas = link;
			//put the link into the double linked entity list of the area
			link->prev_ent = NULL;
			link->next_ent = ( *aasworld ).arealinkedentities[-nodenum];
			if ( ( *aasworld ).arealinkedentities[-nodenum] ) {
				( *aasworld ).arealinkedentities[-nodenum]->prev_ent = link;
			}
			( *aasworld ).arealinkedentities[-nodenum] = link;
			//
			continue;
		} //end if
		  //if solid leaf
		if ( !nodenum ) {
			continue;
		}
		//the node to test against
		aasnode = &( *aasworld ).nodes[nodenum];
		//the current node plane
		plane = &( *aasworld ).planes[aasnode->planenum];
		//get the side(s) the box is situated relative to the plane
		side = AAS_BoxOnPlaneSide2( absmins, absmaxs, plane );
		//if on the front side of the node
		if ( side & 1 ) {
			lstack_p->nodenum = aasnode->children[0];
			lstack_p++;
		} //end if
		if ( lstack_p >= &linkstack[127] ) {
			botimport.Print( PRT_ERROR, "AAS_LinkEntity: stack overflow\n" );
			break;
		} //end if
		  //if on the back side of the node
		if ( side & 2 ) {
			lstack_p->nodenum = aasnode->children[1];
			lstack_p++;
		} //end if
		if ( lstack_p >= &linkstack[127] ) {
			botimport.Print( PRT_ERROR, "AAS_LinkEntity: stack overflow\n" );
			break;
		} //end if
	} //end while
	return areas;
} //end of the function AAS_AASLinkEntity
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
aas_link_t *AAS_LinkEntityClientBBox( vec3_t absmins, vec3_t absmaxs, int entnum, int presencetype ) {
	vec3_t mins, maxs;
	vec3_t newabsmins, newabsmaxs;

	AAS_PresenceTypeBoundingBox( presencetype, mins, maxs );
	VectorSubtract( absmins, maxs, newabsmins );
	VectorSubtract( absmaxs, mins, newabsmaxs );
	//relink the entity
	return AAS_AASLinkEntity( newabsmins, newabsmaxs, entnum );
} //end of the function AAS_LinkEntityClientBBox
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
aas_plane_t *AAS_PlaneFromNum( int planenum ) {
	if ( !( *aasworld ).loaded ) {
		return NULL;
	}

	return &( *aasworld ).planes[planenum];
} //end of the function AAS_PlaneFromNum

/*
=============
AAS_BBoxAreas
=============
*/
int AAS_BBoxAreas( vec3_t absmins, vec3_t absmaxs, int *areas, int maxareas ) {
	aas_link_t *linkedareas, *link;
	int num;

	linkedareas = AAS_AASLinkEntity( absmins, absmaxs, -1 );
	num = 0;
	for ( link = linkedareas; link; link = link->next_area )
	{
		areas[num] = link->areanum;
		num++;
		if ( num >= maxareas ) {
			break;
		}
	} //end for
	AAS_UnlinkFromAreas( linkedareas );
	return num;
} //end of the function AAS_BBoxAreas
