jedi-academy/codemp/qcommon/cm_polylib.h

// this is only used for visualization tools in cm_ debug functions

typedef struct
{
	int		numpoints;
	vec3_t	p[4];		// variable sized
} winding_t;

#define	MAX_POINTS_ON_WINDING	64

#define	SIDE_FRONT	0
#define	SIDE_BACK	1
#define	SIDE_ON		2
#define	SIDE_CROSS	3

#define	CLIP_EPSILON	0.1f

#define MAX_MAP_BOUNDS			65535

// you can define on_epsilon in the makefile as tighter
#ifndef	ON_EPSILON
#define	ON_EPSILON	0.1f
#endif

winding_t	*AllocWinding (int points);
vec_t	WindingArea (winding_t *w);
void	WindingCenter (winding_t *w, vec3_t center);
void	ClipWindingEpsilon (winding_t *in, vec3_t normal, vec_t dist, 
				vec_t epsilon, winding_t **front, winding_t **back);
winding_t	*ChopWinding (winding_t *in, vec3_t normal, vec_t dist);
winding_t	*CopyWinding (winding_t *w);
winding_t	*ReverseWinding (winding_t *w);
winding_t	*BaseWindingForPlane (vec3_t normal, vec_t dist);
void	CheckWinding (winding_t *w);
void	WindingPlane (winding_t *w, vec3_t normal, vec_t *dist);
void	RemoveColinearPoints (winding_t *w);
int		WindingOnPlaneSide (winding_t *w, vec3_t normal, vec_t dist);
void	FreeWinding (winding_t *w);
void	WindingBounds (winding_t *w, vec3_t mins, vec3_t maxs);

void	AddWindingToConvexHull( winding_t *w, winding_t **hull, vec3_t normal );

void	ChopWindingInPlace (winding_t **w, vec3_t normal, vec_t dist, vec_t epsilon);
// frees the original if clipped

void pw(winding_t *w);