l_poly.h

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

//a winding gives the bounding points of a convex polygon
typedef struct
{
    int     numpoints;
    vec3_t  p[4];           //variable sized
} winding_t;

#define MAX_POINTS_ON_WINDING   96

//you can define on_epsilon in the makefile as tighter
#ifndef ON_EPSILON
#define ON_EPSILON  0.1
#endif
//winding errors
#define WE_NONE                     0
#define WE_NOTENOUGHPOINTS          1
#define WE_SMALLAREA                    2
#define WE_POINTBOGUSRANGE          3
#define WE_POINTOFFPLANE            4
#define WE_DEGENERATEEDGE           5
#define WE_NONCONVEX                    6

//allocates a winding
winding_t *AllocWinding (int points);
//returns the area of the winding
vec_t WindingArea (winding_t *w);
//gives the center of the winding
void WindingCenter (winding_t *w, vec3_t center);
//clips the given winding to the given plane and gives the front
//and back part of the clipped winding
void ClipWindingEpsilon (winding_t *in, vec3_t normal, vec_t dist, 
                    vec_t epsilon, winding_t **front, winding_t **back);
//returns the fragment of the given winding that is on the front
//side of the cliping plane. The original is freed.
winding_t *ChopWinding (winding_t *in, vec3_t normal, vec_t dist);
//returns a copy of the given winding
winding_t *CopyWinding (winding_t *w);
//returns the reversed winding of the given one
winding_t *ReverseWinding (winding_t *w);
//returns a base winding for the given plane
winding_t *BaseWindingForPlane (vec3_t normal, vec_t dist);
//checks the winding for errors
void CheckWinding (winding_t *w);
//returns the plane normal and dist the winding is in
void WindingPlane(winding_t *w, vec3_t normal, vec_t *dist);
//removes colinear points from the winding
void RemoveColinearPoints(winding_t *w);
//returns on which side of the plane the winding is situated
int WindingOnPlaneSide(winding_t *w, vec3_t normal, vec_t dist);
//frees the winding
void FreeWinding(winding_t *w);
//gets the bounds of the winding
void WindingBounds(winding_t *w, vec3_t mins, vec3_t maxs);
//chops the winding with the given plane, the original winding is freed if clipped
void ChopWindingInPlace (winding_t **w, vec3_t normal, vec_t dist, vec_t epsilon);
//prints the winding points on STDOUT
void pw(winding_t *w);
//try to merge the two windings which are in the given plane
//the original windings are undisturbed
//the merged winding is returned when merging was possible
//NULL is returned otherwise
winding_t *TryMergeWinding (winding_t *f1, winding_t *f2, vec3_t planenormal);
//brute force winding merging... creates a convex winding out of
//the two whatsoever
winding_t *MergeWindings(winding_t *w1, winding_t *w2, vec3_t planenormal);

//#ifdef ME
void ResetWindings(void);
//returns the amount of winding memory
int WindingMemory(void);
int WindingPeakMemory(void);
int ActiveWindings(void);
//returns the winding error string
char *WindingErrorString(void);
//returns one of the WE_ flags when the winding has errors
int WindingError(winding_t *w);
//removes equal points from the winding
void RemoveEqualPoints(winding_t *w, float epsilon);
//returns a winding with a point added at the given spot to the
//given winding, original winding is NOT freed
winding_t *AddWindingPoint(winding_t *w, vec3_t point, int spot);
//returns true if the point is on one of the winding 'edges'
//when the point is on one of the edged the number of the first
//point of the edge is stored in 'spot' 
int PointOnWinding(winding_t *w, vec3_t normal, float dist, vec3_t point, int *spot);
//find a plane seperating the two windings
//true is returned when the windings area adjacent
//the seperating plane normal and distance area stored in 'normal' and 'dist'
//this plane will contain both the piece of common edge of the two windings
//and the vector 'dir'
int FindPlaneSeperatingWindings(winding_t *w1, winding_t *w2, vec3_t dir,
                                            vec3_t normal, float *dist);
//
int WindingsNonConvex(winding_t *w1, winding_t *w2,
                             vec3_t normal1, vec3_t normal2,
                             float dist1, float dist2);
//#endif //ME

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