diff options
| author | zakk <zakk@edf5b092-35ff-0310-97b2-ce42778d08ea> | 2005-08-26 04:48:05 +0000 | 
|---|---|---|
| committer | zakk <zakk@edf5b092-35ff-0310-97b2-ce42778d08ea> | 2005-08-26 04:48:05 +0000 | 
| commit | 952c5c128f9efaea89d41d882c4ea3ade7df4591 (patch) | |
| tree | 91b84d9be7afad7e99ac64a640a65b6cb5081900 /code/bspc/tetrahedron.c | |
| parent | c2c2e0d25d6cdb7d42d7dc981a863f65f94f281d (diff) | |
| download | ioquake3-aero-952c5c128f9efaea89d41d882c4ea3ade7df4591.tar.gz ioquake3-aero-952c5c128f9efaea89d41d882c4ea3ade7df4591.zip | |
Itsa me, quake3io!
git-svn-id: svn://svn.icculus.org/quake3/trunk@2 edf5b092-35ff-0310-97b2-ce42778d08ea
Diffstat (limited to 'code/bspc/tetrahedron.c')
| -rwxr-xr-x | code/bspc/tetrahedron.c | 1389 | 
1 files changed, 1389 insertions, 0 deletions
| diff --git a/code/bspc/tetrahedron.c b/code/bspc/tetrahedron.c new file mode 100755 index 0000000..36c10af --- /dev/null +++ b/code/bspc/tetrahedron.c @@ -0,0 +1,1389 @@ +/*
 +===========================================================================
 +Copyright (C) 1999-2005 Id Software, Inc.
 +
 +This file is part of Quake III Arena source code.
 +
 +Quake III Arena 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 2 of the License,
 +or (at your option) any later version.
 +
 +Quake III Arena 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 Foobar; if not, write to the Free Software
 +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 +===========================================================================
 +*/
 +
 +#include "qbsp.h"
 +#include "l_mem.h"
 +#include "../botlib/aasfile.h"
 +#include "aas_store.h"
 +#include "aas_cfg.h"
 +#include "aas_file.h"
 +
 +//
 +// creating tetrahedrons from a arbitrary world bounded by triangles
 +//
 +// a triangle has 3 corners and 3 edges
 +// a tetrahedron is build out of 4 triangles
 +// a tetrahedron has 6 edges
 +// we start with a world bounded by triangles, a side of a triangle facing
 +// towards the oudside of the world is marked as part of tetrahedron -1
 +//
 +// a tetrahedron is defined by two non-coplanar triangles with a shared edge
 +//
 +// a tetrahedron is defined by one triangle and a vertex not in the triangle plane
 +//
 +// if all triangles using a specific vertex have tetrahedrons
 +// at both sides then this vertex will never be part of a new tetrahedron
 +//
 +// if all triangles using a specific edge have tetrahedrons
 +// at both sides then this vertex will never be part of a new tetrahedron
 +//
 +// each triangle can only be shared by two tetrahedrons
 +// when all triangles have tetrahedrons at both sides then we're done
 +//
 +// if we cannot create any new tetrahedrons and there is at least one triangle
 +// which has a tetrahedron only at one side then the world leaks
 +//
 +
 +#define Sign(x)		(x < 0 ? 1 : 0)
 +
 +#define MAX_TH_VERTEXES			128000
 +#define MAX_TH_PLANES			128000
 +#define MAX_TH_EDGES			512000
 +#define MAX_TH_TRIANGLES		51200
 +#define MAX_TH_TETRAHEDRONS		12800
 +
 +#define PLANEHASH_SIZE			1024
 +#define EDGEHASH_SIZE			1024
 +#define TRIANGLEHASH_SIZE		1024
 +#define VERTEXHASH_SHIFT		7
 +#define VERTEXHASH_SIZE			((MAX_MAP_BOUNDS>>(VERTEXHASH_SHIFT-1))+1)	//was 64
 +
 +#define	NORMAL_EPSILON			0.0001
 +#define DIST_EPSILON			0.1
 +#define VERTEX_EPSILON			0.01
 +#define INTEGRAL_EPSILON		0.01
 +
 +
 +//plane
 +typedef struct th_plane_s
 +{
 +	vec3_t normal;
 +	float dist;
 +	int type;
 +	int signbits;
 +	struct th_plane_s *hashnext;		//next plane in hash
 +} th_plane_t;
 +
 +//vertex
 +typedef struct th_vertex_s
 +{
 +	vec3_t v;
 +	int usercount;						//2x the number of to be processed
 +										//triangles using this vertex
 +	struct th_vertex_s *hashnext;		//next vertex in hash
 +} th_vertex_t;
 +
 +//edge
 +typedef struct th_edge_s
 +{
 +	int v[2];							//vertex indexes
 +	int usercount;						//number of to be processed
 +										//triangles using this edge
 +	struct th_edge_s *hashnext;			//next edge in hash
 +} th_edge_t;
 +
 +//triangle
 +typedef struct th_triangle_s
 +{
 +	int edges[3];						//negative if edge is flipped
 +	th_plane_t planes[3];				//triangle bounding planes
 +	int planenum;						//plane the triangle is in
 +	int front;							//tetrahedron at the front
 +	int back;							//tetrahedron at the back
 +	vec3_t mins, maxs;					//triangle bounding box
 +	struct th_triangle_s *prev, *next;	//links in linked triangle lists
 +	struct th_triangle_s *hashnext;		//next triangle in hash
 +} th_triangle_t;
 +
 +//tetrahedron
 +typedef struct th_tetrahedron_s
 +{
 +	int triangles[4];					//negative if at backside of triangle
 +	float volume;						//tetrahedron volume
 +} th_tetrahedron_t;
 +
 +typedef struct th_s
 +{
 +	//vertexes
 +	int numvertexes;
 +	th_vertex_t *vertexes;
 +	th_vertex_t *vertexhash[VERTEXHASH_SIZE * VERTEXHASH_SIZE];
 +	//planes
 +	int numplanes;
 +	th_plane_t *planes;
 +	th_plane_t *planehash[PLANEHASH_SIZE];
 +	//edges
 +	int numedges;
 +	th_edge_t *edges;
 +	th_edge_t *edgehash[EDGEHASH_SIZE];
 +	//triangles
 +	int numtriangles;
 +	th_triangle_t *triangles;
 +	th_triangle_t *trianglehash[TRIANGLEHASH_SIZE];
 +	//tetrahedrons
 +	int numtetrahedrons;
 +	th_tetrahedron_t *tetrahedrons;
 +} th_t;
 +
 +th_t thworld;
 +
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_InitMaxTH(void)
 +{
 +	//get memory for the tetrahedron data
 +	thworld.vertexes = (th_vertex_t *) GetClearedMemory(MAX_TH_VERTEXES * sizeof(th_vertex_t));
 +	thworld.planes = (th_plane_t *) GetClearedMemory(MAX_TH_PLANES * sizeof(th_plane_t));
 +	thworld.edges = (th_edge_t *) GetClearedMemory(MAX_TH_EDGES * sizeof(th_edge_t));
 +	thworld.triangles = (th_triangle_t *) GetClearedMemory(MAX_TH_TRIANGLES * sizeof(th_triangle_t));
 +	thworld.tetrahedrons = (th_tetrahedron_t *) GetClearedMemory(MAX_TH_TETRAHEDRONS * sizeof(th_tetrahedron_t));
 +	//reset the hash tables
 +	memset(thworld.vertexhash, 0, VERTEXHASH_SIZE * sizeof(th_vertex_t *));
 +	memset(thworld.planehash, 0, PLANEHASH_SIZE * sizeof(th_plane_t *));
 +	memset(thworld.edgehash, 0, EDGEHASH_SIZE * sizeof(th_edge_t *));
 +	memset(thworld.trianglehash, 0, TRIANGLEHASH_SIZE * sizeof(th_triangle_t *));
 +} //end of the function TH_InitMaxTH
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_FreeMaxTH(void)
 +{
 +	if (thworld.vertexes) FreeMemory(thworld.vertexes);
 +	thworld.vertexes = NULL;
 +	thworld.numvertexes = 0;
 +	if (thworld.planes) FreeMemory(thworld.planes);
 +	thworld.planes = NULL;
 +	thworld.numplanes = 0;
 +	if (thworld.edges) FreeMemory(thworld.edges);
 +	thworld.edges = NULL;
 +	thworld.numedges = 0;
 +	if (thworld.triangles) FreeMemory(thworld.triangles);
 +	thworld.triangles = NULL;
 +	thworld.numtriangles = 0;
 +	if (thworld.tetrahedrons) FreeMemory(thworld.tetrahedrons);
 +	thworld.tetrahedrons = NULL;
 +	thworld.numtetrahedrons = 0;
 +} //end of the function TH_FreeMaxTH
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +float TH_TriangleArea(th_triangle_t *tri)
 +{
 +	return 0;
 +} //end of the function TH_TriangleArea
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +float TH_TetrahedronVolume(th_tetrahedron_t *tetrahedron)
 +{
 +	int edgenum, verts[3], i, j, v2;
 +	float volume, d;
 +	th_triangle_t *tri, *tri2;
 +	th_plane_t *plane;
 +
 +	tri = &thworld.triangles[abs(tetrahedron->triangles[0])];
 +	for (i = 0; i < 3; i++)
 +	{
 +		edgenum = tri->edges[i];
 +		if (edgenum < 0) verts[i] = thworld.edges[abs(edgenum)].v[1];
 +		else verts[i] = thworld.edges[edgenum].v[0];
 +	} //end for
 +	//
 +	tri2 = &thworld.triangles[abs(tetrahedron->triangles[1])];
 +	for (j = 0; j < 3; j++)
 +	{
 +		edgenum = tri2->edges[i];
 +		if (edgenum < 0) v2 = thworld.edges[abs(edgenum)].v[1];
 +		else v2 = thworld.edges[edgenum].v[0];
 +		if (v2 != verts[0] &&
 +			v2 != verts[1] &&
 +			v2 != verts[2]) break;
 +	} //end for
 +
 +	plane = &thworld.planes[tri->planenum];
 +	d = -(DotProduct (thworld.vertexes[v2].v, plane->normal) - plane->dist);
 +	volume = TH_TriangleArea(tri) * d / 3;
 +	return volume;
 +} //end of the function TH_TetrahedronVolume
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_PlaneSignBits(vec3_t normal)
 +{
 +	int i, signbits;
 +
 +	signbits = 0;
 +	for (i = 2; i >= 0; i--)
 +	{
 +		signbits = (signbits << 1) + Sign(normal[i]);
 +	} //end for
 +	return signbits;
 +} //end of the function TH_PlaneSignBits
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_PlaneTypeForNormal(vec3_t normal)
 +{
 +	vec_t	ax, ay, az;
 +	
 +// NOTE: should these have an epsilon around 1.0?		
 +	if (normal[0] == 1.0 || normal[0] == -1.0)
 +		return PLANE_X;
 +	if (normal[1] == 1.0 || normal[1] == -1.0)
 +		return PLANE_Y;
 +	if (normal[2] == 1.0 || normal[2] == -1.0)
 +		return PLANE_Z;
 +		
 +	ax = fabs(normal[0]);
 +	ay = fabs(normal[1]);
 +	az = fabs(normal[2]);
 +	
 +	if (ax >= ay && ax >= az)
 +		return PLANE_ANYX;
 +	if (ay >= ax && ay >= az)
 +		return PLANE_ANYY;
 +	return PLANE_ANYZ;
 +} //end of the function TH_PlaneTypeForNormal
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +qboolean TH_PlaneEqual(th_plane_t *p, vec3_t normal, vec_t dist)
 +{
 +	if (
 +	   fabs(p->normal[0] - normal[0]) < NORMAL_EPSILON
 +	&& fabs(p->normal[1] - normal[1]) < NORMAL_EPSILON
 +	&& fabs(p->normal[2] - normal[2]) < NORMAL_EPSILON
 +	&& fabs(p->dist - dist) < DIST_EPSILON )
 +		return true;
 +	return false;
 +} //end of the function TH_PlaneEqual
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_AddPlaneToHash(th_plane_t *p)
 +{
 +	int hash;
 +
 +	hash = (int)fabs(p->dist) / 8;
 +	hash &= (PLANEHASH_SIZE-1);
 +
 +	p->hashnext = thworld.planehash[hash];
 +	thworld.planehash[hash] = p;
 +} //end of the function TH_AddPlaneToHash
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_CreateFloatPlane(vec3_t normal, vec_t dist)
 +{
 +	th_plane_t *p, temp;
 +
 +	if (VectorLength(normal) < 0.5)
 +		Error ("FloatPlane: bad normal");
 +	// create a new plane
 +	if (thworld.numplanes+2 > MAX_TH_PLANES)
 +		Error ("MAX_TH_PLANES");
 +
 +	p = &thworld.planes[thworld.numplanes];
 +	VectorCopy (normal, p->normal);
 +	p->dist = dist;
 +	p->type = (p+1)->type = TH_PlaneTypeForNormal (p->normal);
 +	p->signbits = TH_PlaneSignBits(p->normal);
 +
 +	VectorSubtract (vec3_origin, normal, (p+1)->normal);
 +	(p+1)->dist = -dist;
 +	(p+1)->signbits = TH_PlaneSignBits((p+1)->normal);
 +
 +	thworld.numplanes += 2;
 +
 +	// allways put axial planes facing positive first
 +	if (p->type < 3)
 +	{
 +		if (p->normal[0] < 0 || p->normal[1] < 0 || p->normal[2] < 0)
 +		{
 +			// flip order
 +			temp = *p;
 +			*p = *(p+1);
 +			*(p+1) = temp;
 +
 +			TH_AddPlaneToHash(p);
 +			TH_AddPlaneToHash(p+1);
 +			return thworld.numplanes - 1;
 +		} //end if
 +	} //end if
 +
 +	TH_AddPlaneToHash(p);
 +	TH_AddPlaneToHash(p+1);
 +	return thworld.numplanes - 2;
 +} //end of the function TH_CreateFloatPlane
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_SnapVector(vec3_t normal)
 +{
 +	int		i;
 +
 +	for (i = 0; i < 3; i++)
 +	{
 +		if ( fabs(normal[i] - 1) < NORMAL_EPSILON )
 +		{
 +			VectorClear (normal);
 +			normal[i] = 1;
 +			break;
 +		} //end if
 +		if ( fabs(normal[i] - -1) < NORMAL_EPSILON )
 +		{
 +			VectorClear (normal);
 +			normal[i] = -1;
 +			break;
 +		} //end if
 +	} //end for
 +} //end of the function TH_SnapVector
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_SnapPlane(vec3_t normal, vec_t *dist)
 +{
 +	TH_SnapVector(normal);
 +
 +	if (fabs(*dist-Q_rint(*dist)) < DIST_EPSILON)
 +		*dist = Q_rint(*dist);
 +} //end of the function TH_SnapPlane
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_FindFloatPlane(vec3_t normal, vec_t dist)
 +{
 +	int i;
 +	th_plane_t *p;
 +	int hash, h;
 +
 +	TH_SnapPlane (normal, &dist);
 +	hash = (int)fabs(dist) / 8;
 +	hash &= (PLANEHASH_SIZE-1);
 +
 +	// search the border bins as well
 +	for (i = -1; i <= 1; i++)
 +	{
 +		h = (hash+i)&(PLANEHASH_SIZE-1);
 +		for (p = thworld.planehash[h]; p; p = p->hashnext)
 +		{
 +			if (TH_PlaneEqual(p, normal, dist))
 +			{
 +				return p - thworld.planes;
 +			} //end if
 +		} //end for
 +	} //end for
 +	return TH_CreateFloatPlane(normal, dist);
 +} //end of the function TH_FindFloatPlane
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_PlaneFromPoints(int v1, int v2, int v3)
 +{
 +	vec3_t t1, t2, normal;
 +	vec_t dist;
 +	float *p0, *p1, *p2;
 +
 +	p0 = thworld.vertexes[v1].v;
 +	p1 = thworld.vertexes[v2].v;
 +	p2 = thworld.vertexes[v3].v;
 +
 +	VectorSubtract(p0, p1, t1);
 +	VectorSubtract(p2, p1, t2);
 +	CrossProduct(t1, t2, normal);
 +	VectorNormalize(normal);
 +
 +	dist = DotProduct(p0, normal);
 +
 +	return TH_FindFloatPlane(normal, dist);
 +} //end of the function TH_PlaneFromPoints
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_AddEdgeUser(int edgenum)
 +{
 +	th_edge_t *edge;
 +
 +	edge = &thworld.edges[abs(edgenum)];
 +	//increase edge user count
 +	edge->usercount++;
 +	//increase vertex user count as well
 +	thworld.vertexes[edge->v[0]].usercount++;
 +	thworld.vertexes[edge->v[1]].usercount++;
 +} //end of the function TH_AddEdgeUser
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_RemoveEdgeUser(int edgenum)
 +{
 +	th_edge_t *edge;
 +
 +	edge = &thworld.edges[abs(edgenum)];
 +	//decrease edge user count
 +	edge->usercount--;
 +	//decrease vertex user count as well
 +	thworld.vertexes[edge->v[0]].usercount--;
 +	thworld.vertexes[edge->v[1]].usercount--;
 +} //end of the function TH_RemoveEdgeUser
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_FreeTriangleEdges(th_triangle_t *tri)
 +{
 +	int i;
 +
 +	for (i = 0; i < 3; i++)
 +	{
 +		TH_RemoveEdgeUser(abs(tri->edges[i]));
 +	} //end for
 +} //end of the function TH_FreeTriangleEdges
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +unsigned TH_HashVec(vec3_t vec)
 +{
 +	int x, y;
 +
 +	x = (MAX_MAP_BOUNDS + (int)(vec[0]+0.5)) >> VERTEXHASH_SHIFT;
 +	y = (MAX_MAP_BOUNDS + (int)(vec[1]+0.5)) >> VERTEXHASH_SHIFT;
 +
 +	if (x < 0 || x >= VERTEXHASH_SIZE || y < 0 || y >= VERTEXHASH_SIZE)
 +		Error("HashVec: point %f %f %f outside valid range", vec[0], vec[1], vec[2]);
 +	
 +	return y*VERTEXHASH_SIZE + x;
 +} //end of the function TH_HashVec
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_FindVertex(vec3_t v)
 +{
 +	int i, h;
 +	th_vertex_t *vertex;
 +	vec3_t vert;
 +	
 +	for (i = 0; i < 3; i++)
 +	{
 +		if ( fabs(v[i] - Q_rint(v[i])) < INTEGRAL_EPSILON)
 +			vert[i] = Q_rint(v[i]);
 +		else
 +			vert[i] = v[i];
 +	} //end for
 +
 +	h = TH_HashVec(vert);
 +
 +	for (vertex = thworld.vertexhash[h]; vertex; vertex = vertex->hashnext)
 +	{
 +		if (fabs(vertex->v[0] - vert[0]) < VERTEX_EPSILON &&
 +			fabs(vertex->v[1] - vert[1]) < VERTEX_EPSILON &&
 +			fabs(vertex->v[2] - vert[2]) < VERTEX_EPSILON)
 +		{
 +			return vertex - thworld.vertexes;
 +		} //end if
 +	} //end for
 +	return 0;
 +} //end of the function TH_FindVertex
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_AddVertexToHash(th_vertex_t *vertex)
 +{
 +	int hashvalue;
 +
 +	hashvalue = TH_HashVec(vertex->v);
 +	vertex->hashnext = thworld.vertexhash[hashvalue];
 +	thworld.vertexhash[hashvalue] = vertex;
 +} //end of the function TH_AddVertexToHash
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_CreateVertex(vec3_t v)
 +{
 +	if (thworld.numvertexes == 0) thworld.numvertexes = 1;
 +	if (thworld.numvertexes >= MAX_TH_VERTEXES)
 +		Error("MAX_TH_VERTEXES");
 +	VectorCopy(v, thworld.vertexes[thworld.numvertexes].v);
 +	thworld.vertexes[thworld.numvertexes].usercount = 0;
 +	TH_AddVertexToHash(&thworld.vertexes[thworld.numvertexes]);
 +	thworld.numvertexes++;
 +	return thworld.numvertexes-1;
 +} //end of the function TH_CreateVertex
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_FindOrCreateVertex(vec3_t v)
 +{
 +	int vertexnum;
 +
 +	vertexnum = TH_FindVertex(v);
 +	if (!vertexnum) vertexnum = TH_CreateVertex(v);
 +	return vertexnum;
 +} //end of the function TH_FindOrCreateVertex
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_FindEdge(int v1, int v2)
 +{
 +	int hashvalue;
 +	th_edge_t *edge;
 +
 +	hashvalue = (v1 + v2) & (EDGEHASH_SIZE-1);
 +
 +	for (edge = thworld.edgehash[hashvalue]; edge; edge = edge->hashnext)
 +	{
 +		if (edge->v[0] == v1 && edge->v[1] == v2) return edge - thworld.edges;
 +		if (edge->v[1] == v1 && edge->v[0] == v2) return -(edge - thworld.edges);
 +	} //end for
 +	return 0;
 +} //end of the function TH_FindEdge
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_AddEdgeToHash(th_edge_t *edge)
 +{
 +	int hashvalue;
 +
 +	hashvalue = (edge->v[0] + edge->v[1]) & (EDGEHASH_SIZE-1);
 +	edge->hashnext = thworld.edgehash[hashvalue];
 +	thworld.edgehash[hashvalue] = edge;
 +} //end of the function TH_AddEdgeToHash
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_CreateEdge(int v1, int v2)
 +{
 +	th_edge_t *edge;
 +
 +	if (thworld.numedges == 0) thworld.numedges = 1;
 +	if (thworld.numedges >= MAX_TH_EDGES)
 +		Error("MAX_TH_EDGES");
 +	edge = &thworld.edges[thworld.numedges++];
 +	edge->v[0] = v1;
 +	edge->v[1] = v2;
 +	TH_AddEdgeToHash(edge);
 +	return thworld.numedges-1;
 +} //end of the function TH_CreateEdge
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_FindOrCreateEdge(int v1, int v2)
 +{
 +	int edgenum;
 +
 +	edgenum = TH_FindEdge(v1, v2);
 +	if (!edgenum) edgenum = TH_CreateEdge(v1, v2);
 +	return edgenum;
 +} //end of the function TH_FindOrCreateEdge
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_FindTriangle(int verts[3])
 +{
 +	int i, hashvalue, edges[3];
 +	th_triangle_t *tri;
 +
 +	for (i = 0; i < 3; i++)
 +	{
 +		edges[i] = TH_FindEdge(verts[i], verts[(i+1)%3]);
 +		if (!edges[i]) return false;
 +	} //end for
 +	hashvalue = (abs(edges[0]) + abs(edges[1]) + abs(edges[2])) & (TRIANGLEHASH_SIZE-1);
 +	for (tri = thworld.trianglehash[hashvalue]; tri; tri = tri->next)
 +	{
 +		for (i = 0; i < 3; i++)
 +		{
 +			if (abs(tri->edges[i]) != abs(edges[0]) &&
 +				abs(tri->edges[i]) != abs(edges[1]) &&
 +				abs(tri->edges[i]) != abs(edges[2])) break;
 +		} //end for
 +		if (i >= 3) return tri - thworld.triangles;
 +	} //end for
 +	return 0;
 +} //end of the function TH_FindTriangle
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_AddTriangleToHash(th_triangle_t *tri)
 +{
 +	int hashvalue;
 +
 +	hashvalue = (abs(tri->edges[0]) + abs(tri->edges[1]) + abs(tri->edges[2])) & (TRIANGLEHASH_SIZE-1);
 +	tri->hashnext = thworld.trianglehash[hashvalue];
 +	thworld.trianglehash[hashvalue] = tri;
 +} //end of the function TH_AddTriangleToHash
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_CreateTrianglePlanes(int verts[3], th_plane_t *triplane, th_plane_t *planes)
 +{
 +	int i;
 +	vec3_t dir;
 +
 +	for (i = 0; i < 3; i++)
 +	{
 +		VectorSubtract(thworld.vertexes[verts[(i+1)%3]].v, thworld.vertexes[verts[i]].v, dir);
 +		CrossProduct(dir, triplane->normal, planes[i].normal);
 +		VectorNormalize(planes[i].normal);
 +		planes[i].dist = DotProduct(thworld.vertexes[verts[i]].v, planes[i].normal);
 +	} //end for
 +} //end of the function TH_CreateTrianglePlanes
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_CreateTriangle(int verts[3])
 +{
 +	th_triangle_t *tri;
 +	int i;
 +
 +	if (thworld.numtriangles == 0) thworld.numtriangles = 1;
 +	if (thworld.numtriangles >= MAX_TH_TRIANGLES)
 +		Error("MAX_TH_TRIANGLES");
 +	tri = &thworld.triangles[thworld.numtriangles++];
 +	for (i = 0; i < 3; i++)
 +	{
 +		tri->edges[i] = TH_FindOrCreateEdge(verts[i], verts[(i+1)%3]);
 +		TH_AddEdgeUser(abs(tri->edges[i]));
 +	} //end for
 +	tri->front = 0;
 +	tri->back = 0;
 +	tri->planenum = TH_PlaneFromPoints(verts[0], verts[1], verts[2]);
 +	tri->prev = NULL;
 +	tri->next = NULL;
 +	tri->hashnext = NULL;
 +	TH_CreateTrianglePlanes(verts, &thworld.planes[tri->planenum], tri->planes);
 +	TH_AddTriangleToHash(tri);
 +	ClearBounds(tri->mins, tri->maxs);
 +	for (i = 0; i < 3; i++)
 +	{
 +		AddPointToBounds(thworld.vertexes[verts[i]].v, tri->mins, tri->maxs);
 +	} //end for
 +	return thworld.numtriangles-1;
 +} //end of the function TH_CreateTriangle
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_CreateTetrahedron(int triangles[4])
 +{
 +	th_tetrahedron_t *tetrahedron;
 +	int i;
 +
 +	if (thworld.numtetrahedrons == 0) thworld.numtetrahedrons = 1;
 +	if (thworld.numtetrahedrons >= MAX_TH_TETRAHEDRONS)
 +		Error("MAX_TH_TETRAHEDRONS");
 +	tetrahedron = &thworld.tetrahedrons[thworld.numtetrahedrons++];
 +	for (i = 0; i < 4; i++)
 +	{
 +		tetrahedron->triangles[i] = triangles[i];
 +		if (thworld.triangles[abs(triangles[i])].front)
 +		{
 +			thworld.triangles[abs(triangles[i])].back = thworld.numtetrahedrons-1;
 +		} //end if
 +		else
 +		{
 +			thworld.triangles[abs(triangles[i])].front = thworld.numtetrahedrons-1;
 +		} //end else
 +	} //end for
 +	tetrahedron->volume = 0;
 +	return thworld.numtetrahedrons-1;
 +} //end of the function TH_CreateTetrahedron
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_IntersectTrianglePlanes(int v1, int v2, th_plane_t *triplane, th_plane_t *planes)
 +{
 +	float *p1, *p2, front, back, frac, d;
 +	int i, side, lastside;
 +	vec3_t mid;
 +
 +	p1 = thworld.vertexes[v1].v;
 +	p2 = thworld.vertexes[v2].v;
 +
 +	front = DotProduct(p1, triplane->normal) - triplane->dist;
 +	back = DotProduct(p2, triplane->normal) - triplane->dist;
 +	//if both points at the same side of the plane
 +	if (front < 0.1 && back < 0.1) return false;
 +	if (front > -0.1 && back > -0.1) return false;
 +	//
 +	frac = front/(front-back);
 +	mid[0] = p1[0] + (p2[0] - p1[0]) * frac;
 +	mid[1] = p1[1] + (p2[1] - p1[1]) * frac;
 +	mid[2] = p1[2] + (p2[2] - p1[2]) * frac;
 +	//if the mid point is at the same side of all the tri bounding planes
 +	lastside = 0;
 +	for (i = 0; i < 3; i++)
 +	{
 +		d = DotProduct(mid, planes[i].normal) - planes[i].dist;
 +		side = d < 0;
 +		if (i && side != lastside) return false;
 +		lastside = side;
 +	} //end for
 +	return true;
 +} //end of the function TH_IntersectTrianglePlanes
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_OutsideBoundingBox(int v1, int v2, vec3_t mins, vec3_t maxs)
 +{
 +	float *p1, *p2;
 +	int i;
 +
 +	p1 = thworld.vertexes[v1].v;
 +	p2 = thworld.vertexes[v2].v;
 +	//if both points are at the outer side of one of the bounding box planes
 +	for (i = 0; i < 3; i++)
 +	{
 +		if (p1[i] < mins[i] && p2[i] < mins[i]) return true;
 +		if (p1[i] > maxs[i] && p2[i] > maxs[i]) return true;
 +	} //end for
 +	return false;
 +} //end of the function TH_OutsideBoundingBox
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_TryEdge(int v1, int v2)
 +{
 +	int i, j, v;
 +	th_plane_t *plane;
 +	th_triangle_t *tri;
 +
 +	//if the edge already exists it must be valid
 +	if (TH_FindEdge(v1, v2)) return true;
 +	//test the edge with all existing triangles
 +	for (i = 1; i < thworld.numtriangles; i++)
 +	{
 +		tri = &thworld.triangles[i];
 +		//if triangle is enclosed by two tetrahedrons we don't have to test it
 +		//because the edge always has to go through another triangle of those
 +		//tetrahedrons first to reach the enclosed triangle
 +		if (tri->front && tri->back) continue;
 +		//if the edges is totally outside the triangle bounding box
 +		if (TH_OutsideBoundingBox(v1, v2, tri->mins, tri->maxs)) continue;
 +		//if one of the edge vertexes is used by this triangle
 +		for (j = 0; j < 3; j++)
 +		{
 +			v = thworld.edges[abs(tri->edges[j])].v[tri->edges[j] < 0];
 +			if (v == v1 || v == v2) break;
 +		} //end for
 +		if (j < 3) continue;
 +		//get the triangle plane
 +		plane = &thworld.planes[tri->planenum];
 +		//if the edge intersects with a triangle then it's not valid
 +		if (TH_IntersectTrianglePlanes(v1, v2, plane, tri->planes)) return false;
 +	} //end for
 +	return true;
 +} //end of the function TH_TryEdge
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_TryTriangle(int verts[3])
 +{
 +	th_plane_t planes[3], triplane;
 +	vec3_t t1, t2;
 +	float *p0, *p1, *p2;
 +	int i, j;
 +
 +	p0 = thworld.vertexes[verts[0]].v;
 +	p1 = thworld.vertexes[verts[1]].v;
 +	p2 = thworld.vertexes[verts[2]].v;
 +
 +	VectorSubtract(p0, p1, t1);
 +	VectorSubtract(p2, p1, t2);
 +	CrossProduct(t1, t2, triplane.normal);
 +	VectorNormalize(triplane.normal);
 +	triplane.dist = DotProduct(p0, triplane.normal);
 +	//
 +	TH_CreateTrianglePlanes(verts, &triplane, planes);
 +	//test if any existing edge intersects with this triangle
 +	for (i = 1; i < thworld.numedges; i++)
 +	{
 +		//if the edge is only used by triangles with tetrahedrons at both sides
 +		if (!thworld.edges[i].usercount) continue;
 +		//if one of the triangle vertexes is used by this edge
 +		for (j = 0; j < 3; j++)
 +		{
 +			if (verts[j] == thworld.edges[j].v[0] ||
 +				verts[j] == thworld.edges[j].v[1]) break;
 +		} //end for
 +		if (j < 3) continue;
 +		//if this edge intersects with the triangle
 +		if (TH_IntersectTrianglePlanes(thworld.edges[i].v[0], thworld.edges[i].v[1], &triplane, planes)) return false;
 +	} //end for
 +	return true;
 +} //end of the function TH_TryTriangle
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_AddTriangleToList(th_triangle_t **trianglelist, th_triangle_t *tri)
 +{
 +	tri->prev = NULL;
 +	tri->next = *trianglelist;
 +	if (*trianglelist) (*trianglelist)->prev = tri;
 +	*trianglelist = tri;
 +} //end of the function TH_AddTriangleToList
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_RemoveTriangleFromList(th_triangle_t **trianglelist, th_triangle_t *tri)
 +{
 +	if (tri->next) tri->next->prev = tri->prev;
 +	if (tri->prev) tri->prev->next = tri->next;
 +	else *trianglelist = tri->next;
 +} //end of the function TH_RemoveTriangleFromList
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_FindTetrahedron1(th_triangle_t *tri, int *triangles)
 +{
 +	int i, j, edgenum, side, v1, v2, v3, v4;
 +	int verts1[3], verts2[3];
 +	th_triangle_t *tri2;
 +
 +	//find another triangle with a shared edge
 +	for (tri2 = tri->next; tri2; tri2 = tri2->next)
 +	{
 +		//if the triangles are in the same plane
 +		if ((tri->planenum & ~1) == (tri2->planenum & ~1)) continue;
 +		//try to find a shared edge
 +		for (i = 0; i < 3; i++)
 +		{
 +			edgenum = abs(tri->edges[i]);
 +			for (j = 0; j < 3; j++)
 +			{
 +				if (edgenum == abs(tri2->edges[j])) break;
 +			} //end for
 +			if (j < 3) break;
 +		} //end for
 +		//if the triangles have a shared edge
 +		if (i < 3)
 +		{
 +			edgenum = tri->edges[(i+1)%3];
 +			if (edgenum < 0) v1 = thworld.edges[abs(edgenum)].v[0];
 +			else v1 = thworld.edges[edgenum].v[1];
 +			edgenum = tri2->edges[(j+1)%3];
 +			if (edgenum < 0) v2 = thworld.edges[abs(edgenum)].v[0];
 +			else v2 = thworld.edges[edgenum].v[1];
 +			//try the new edge
 +			if (TH_TryEdge(v1, v2))
 +			{
 +				edgenum = tri->edges[i];
 +				side = edgenum < 0;
 +				//get the vertexes of the shared edge
 +				v3 = thworld.edges[abs(edgenum)].v[side];
 +				v4 = thworld.edges[abs(edgenum)].v[!side];
 +				//try the two new triangles
 +				verts1[0] = v1;
 +				verts1[1] = v2;
 +				verts1[2] = v3;
 +				triangles[2] = TH_FindTriangle(verts1);
 +				if (triangles[2] || TH_TryTriangle(verts1))
 +				{
 +					verts2[0] = v2;
 +					verts2[1] = v1;
 +					verts2[2] = v4;
 +					triangles[3] = TH_FindTriangle(verts2);
 +					if (triangles[3] || TH_TryTriangle(verts2))
 +					{
 +						triangles[0] = tri - thworld.triangles;
 +						triangles[1] = tri2 - thworld.triangles;
 +						if (!triangles[2]) triangles[2] = TH_CreateTriangle(verts1);
 +						if (!triangles[3]) triangles[3] = TH_CreateTriangle(verts2);
 +						return true;
 +					} //end if
 +				} //end if
 +			} //end if
 +		} //end if
 +	} //end for
 +	return false;
 +} //end of the function TH_FindTetrahedron
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_FindTetrahedron2(th_triangle_t *tri, int *triangles)
 +{
 +	int i, edgenum, v1, verts[3], triverts[3];
 +	float d;
 +	th_plane_t *plane;
 +
 +	//get the verts of this triangle
 +	for (i = 0; i < 3; i++)
 +	{
 +		edgenum = tri->edges[i];
 +		if (edgenum < 0) verts[i] = thworld.edges[abs(edgenum)].v[1];
 +		else verts[i] = thworld.edges[edgenum].v[0];
 +	} //end for
 +	//
 +	plane = &thworld.planes[tri->planenum];
 +	for (v1 = 0; v1 < thworld.numvertexes; v1++)
 +	{
 +		//if the vertex is only used by triangles with tetrahedrons at both sides
 +		if (!thworld.vertexes[v1].usercount) continue;
 +		//check if the vertex is not coplanar with the triangle
 +		d = DotProduct(thworld.vertexes[v1].v, plane->normal) - plane->dist;
 +		if (fabs(d) < 1) continue;
 +		//check if we can create edges from the triangle towards this new vertex
 +		for (i = 0; i < 3; i++)
 +		{
 +			if (v1 == verts[i]) break;
 +			if (!TH_TryEdge(v1, verts[i])) break;
 +		} //end for
 +		if (i < 3) continue;
 +		//check if the triangles are valid
 +		for (i = 0; i < 3; i++)
 +		{
 +			triverts[0] = v1;
 +			triverts[1] = verts[i];
 +			triverts[2] = verts[(i+1)%3];
 +			//if the triangle already exists then it is valid
 +			triangles[i] = TH_FindTriangle(triverts);
 +			if (!triangles[i])
 +			{
 +				if (!TH_TryTriangle(triverts)) break;
 +			} //end if
 +		} //end for
 +		if (i < 3) continue;
 +		//create the tetrahedron triangles using the new vertex
 +		for (i = 0; i < 3; i++)
 +		{
 +			if (!triangles[i])
 +			{
 +				triverts[0] = v1;
 +				triverts[1] = verts[i];
 +				triverts[2] = verts[(i+1)%3];
 +				triangles[i] = TH_CreateTriangle(triverts);
 +			} //end if
 +		} //end for
 +		//add the existing triangle
 +		triangles[3] = tri - thworld.triangles;
 +		//
 +		return true;
 +	} //end for
 +	return false;
 +} //end of the function TH_FindTetrahedron2
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_TetrahedralDecomposition(th_triangle_t *triangles)
 +{
 +	int i, thtriangles[4], numtriangles;
 +	th_triangle_t *donetriangles, *tri;
 +
 +	donetriangles = NULL;
 +
 +	/*
 +	numtriangles = 0;
 +	qprintf("%6d triangles", numtriangles);
 +	for (tri = triangles; tri; tri = triangles)
 +	{
 +		qprintf("\r%6d", numtriangles++);
 +		if (!TH_FindTetrahedron1(tri, thtriangles))
 +		{
 +//			if (!TH_FindTetrahedron2(tri, thtriangles))
 +			{
 +//				Error("triangle without tetrahedron");
 +				TH_RemoveTriangleFromList(&triangles, tri);
 +				continue;
 +			} //end if
 +		} //end if
 +		//create a tetrahedron from the triangles
 +		TH_CreateTetrahedron(thtriangles);
 +		//
 +		for (i = 0; i < 4; i++)
 +		{
 +			if (thworld.triangles[abs(thtriangles[i])].front &&
 +				thworld.triangles[abs(thtriangles[i])].back)
 +			{
 +				TH_RemoveTriangleFromList(&triangles, &thworld.triangles[abs(thtriangles[i])]);
 +				TH_AddTriangleToList(&donetriangles, &thworld.triangles[abs(thtriangles[i])]);
 +				TH_FreeTriangleEdges(&thworld.triangles[abs(thtriangles[i])]);
 +			} //end if
 +			else
 +			{
 +				TH_AddTriangleToList(&triangles, &thworld.triangles[abs(thtriangles[i])]);
 +			} //end else
 +		} //end for
 +	} //end for*/
 +	qprintf("%6d tetrahedrons", thworld.numtetrahedrons);
 +	do
 +	{
 +		do
 +		{
 +			numtriangles = 0;
 +			for (i = 1; i < thworld.numtriangles; i++)
 +			{
 +				tri = &thworld.triangles[i];
 +				if (tri->front && tri->back) continue;
 +				//qprintf("\r%6d", numtriangles++);
 +				if (!TH_FindTetrahedron1(tri, thtriangles))
 +				{
 +//					if (!TH_FindTetrahedron2(tri, thtriangles))
 +					{
 +						continue;
 +					} //end if
 +				} //end if
 +				numtriangles++;
 +				//create a tetrahedron from the triangles
 +				TH_CreateTetrahedron(thtriangles);
 +				qprintf("\r%6d", thworld.numtetrahedrons);
 +			} //end for
 +		} while(numtriangles);
 + 		for (i = 1; i < thworld.numtriangles; i++)
 +		{
 +			tri = &thworld.triangles[i];
 +			if (tri->front && tri->back) continue;
 +			//qprintf("\r%6d", numtriangles++);
 +//			if (!TH_FindTetrahedron1(tri, thtriangles))
 +			{
 +				if (!TH_FindTetrahedron2(tri, thtriangles))
 +				{
 +					continue;
 +				} //end if
 +			} //end if
 +			numtriangles++;
 +			//create a tetrahedron from the triangles
 +			TH_CreateTetrahedron(thtriangles);
 +			qprintf("\r%6d", thworld.numtetrahedrons);
 +		} //end for
 +	} while(numtriangles);
 +	//
 +	numtriangles = 0;
 +	for (i = 1; i < thworld.numtriangles; i++)
 +	{
 +		tri = &thworld.triangles[i];
 +		if (!tri->front && !tri->back) numtriangles++;
 +	} //end for
 +	Log_Print("\r%6d triangles with front only\n", numtriangles);
 +	Log_Print("\r%6d tetrahedrons\n", thworld.numtetrahedrons-1);
 +} //end of the function TH_TetrahedralDecomposition
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_AASFaceVertex(aas_face_t *face, int index, vec3_t vertex)
 +{
 +	int edgenum, side;
 +
 +	edgenum = aasworld.edgeindex[face->firstedge + index];
 +	side = edgenum < 0;
 +	VectorCopy(aasworld.vertexes[aasworld.edges[abs(edgenum)].v[side]], vertex);
 +} //end of the function TH_AASFaceVertex
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +int TH_Colinear(float *v0, float *v1, float *v2)
 +{
 +	vec3_t t1, t2, vcross;
 +	float d;
 +	
 +	VectorSubtract(v1, v0, t1);
 +	VectorSubtract(v2, v0, t2);
 +	CrossProduct (t1, t2, vcross);
 +	d = VectorLength( vcross );
 +
 +	// if cross product is zero point is colinear
 +	if (d < 10)
 +	{
 +		return true;
 +	} //end if
 +	return false;
 +} //end of the function TH_Colinear
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_FaceCenter(aas_face_t *face, vec3_t center)
 +{
 +	int i, edgenum, side;
 +	aas_edge_t *edge;
 +
 +	VectorClear(center);
 +	for (i = 0; i < face->numedges; i++)
 +	{
 +		edgenum = abs(aasworld.edgeindex[face->firstedge + i]);
 +		side = edgenum < 0;
 +		edge = &aasworld.edges[abs(edgenum)];
 +		VectorAdd(aasworld.vertexes[edge->v[side]], center, center);
 +	} //end for
 +	VectorScale(center, 1.0 / face->numedges, center);
 +} //end of the function TH_FaceCenter
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +th_triangle_t *TH_CreateAASFaceTriangles(aas_face_t *face)
 +{
 +	int i, first, verts[3], trinum;
 +	vec3_t p0, p1, p2, p3, p4, center;
 +	th_triangle_t *tri, *triangles;
 +
 +	triangles = NULL;
 +	//find three points that are not colinear
 +	for (i = 0; i < face->numedges; i++)
 +	{
 +		TH_AASFaceVertex(face, (face->numedges + i-2)%face->numedges, p0);
 +		TH_AASFaceVertex(face, (face->numedges + i-1)%face->numedges, p1);
 +		TH_AASFaceVertex(face, (i  )%face->numedges, p2);
 +		if (TH_Colinear(p2, p0, p1)) continue;
 +		TH_AASFaceVertex(face, (i+1)%face->numedges, p3);
 +		TH_AASFaceVertex(face, (i+2)%face->numedges, p4);
 +		if (TH_Colinear(p2, p3, p4)) continue;
 +		break;
 +	} //end for
 +	//if there are three points that are not colinear
 +	if (i < face->numedges)
 +	{
 +		//normal triangulation
 +		first = i; //left and right most point of three non-colinear points
 +		TH_AASFaceVertex(face, first, p0);
 +		verts[0] = TH_FindOrCreateVertex(p0);
 +		for (i = 1; i < face->numedges-1; i++)
 +		{
 +			TH_AASFaceVertex(face, (first+i  )%face->numedges, p1);
 +			TH_AASFaceVertex(face, (first+i+1)%face->numedges, p2);
 +			verts[1] = TH_FindOrCreateVertex(p1);
 +			verts[2] = TH_FindOrCreateVertex(p2);
 +			trinum = TH_CreateTriangle(verts);
 +			tri = &thworld.triangles[trinum];
 +			tri->front = -1;
 +			TH_AddTriangleToList(&triangles, tri);
 +		} //end for
 +	} //end if
 +	else
 +	{
 +		//fan triangulation
 +		TH_FaceCenter(face, center);
 +		//
 +		verts[0] = TH_FindOrCreateVertex(center);
 +		for (i = 0; i < face->numedges; i++)
 +		{
 +			TH_AASFaceVertex(face, (i  )%face->numedges, p1);
 +			TH_AASFaceVertex(face, (i+1)%face->numedges, p2);
 +			if (TH_Colinear(center, p1, p2)) continue;
 +			verts[1] = TH_FindOrCreateVertex(p1);
 +			verts[2] = TH_FindOrCreateVertex(p2);
 +			trinum = TH_CreateTriangle(verts);
 +			tri = &thworld.triangles[trinum];
 +			tri->front = -1;
 +			TH_AddTriangleToList(&triangles, tri);
 +		} //end for
 +	} //end else
 +	return triangles;
 +} //end of the function TH_CreateAASFaceTriangles
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +th_triangle_t *TH_AASToTriangleMesh(void)
 +{
 +	int i, j, facenum, otherareanum;
 +	aas_face_t *face;
 +	th_triangle_t *tri, *nexttri, *triangles;
 +
 +	triangles = NULL;
 +	for (i = 1; i < aasworld.numareas; i++)
 +	{
 +		//if (!(aasworld.areasettings[i].presencetype & PRESENCE_NORMAL)) continue;
 +		for (j = 0; j < aasworld.areas[i].numfaces; j++)
 +		{
 +			facenum = abs(aasworld.faceindex[aasworld.areas[i].firstface + j]);
 +			face = &aasworld.faces[facenum];
 +			//only convert solid faces into triangles
 +			if (!(face->faceflags & FACE_SOLID))
 +			{
 +				/*
 +				if (face->frontarea == i) otherareanum = face->backarea;
 +				else otherareanum = face->frontarea;
 +				if (aasworld.areasettings[otherareanum].presencetype & PRESENCE_NORMAL) continue;
 +				*/
 +				continue;
 +			} //end if
 +			//
 +			tri = TH_CreateAASFaceTriangles(face);
 +			for (; tri; tri = nexttri)
 +			{
 +				nexttri = tri->next;
 +				TH_AddTriangleToList(&triangles, tri);
 +			} //end for
 +		} //end if
 +	} //end for
 +	return triangles;
 +} //end of the function TH_AASToTriangleMesh
 +//===========================================================================
 +//
 +// Parameter:			-
 +// Returns:				-
 +// Changes Globals:		-
 +//===========================================================================
 +void TH_AASToTetrahedrons(char *filename)
 +{
 +	th_triangle_t *triangles, *tri, *lasttri;
 +	int cnt;
 +
 +	if (!AAS_LoadAASFile(filename, 0, 0))
 +		Error("couldn't load %s\n", filename);
 +
 +	//
 +	TH_InitMaxTH();
 +	//create a triangle mesh from the solid faces in the AAS file
 +	triangles = TH_AASToTriangleMesh();
 +	//
 +	cnt = 0;
 +	lasttri = NULL;
 +	for (tri = triangles; tri; tri = tri->next)
 +	{
 +		cnt++;
 +		if (tri->prev != lasttri) Log_Print("BAH\n");
 +		lasttri = tri;
 +	} //end for
 +	Log_Print("%6d triangles\n", cnt);
 +	//create a tetrahedral decomposition of the world bounded by triangles
 +	TH_TetrahedralDecomposition(triangles);
 +	//
 +	TH_FreeMaxTH();
 +} //end of the function TH_AASToTetrahedrons
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