mathlib.h

/*
Copyright (C) 1996-1997 Id Software, Inc.

This program 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.

This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// mathlib.h

typedef float vec_t;
typedef vec_t vec3_t[3];

#ifndef M_PI
#define M_PI		3.14159265358979323846	// matches value in gcc v2 math.h
#endif

struct mplane_s;
extern vec3_t vec3_origin;
extern int nanmask;

#define	IS_NAN(x) (((*(int *)&x)&nanmask)==nanmask)
#define anglemod(a) (((int) ((a) * (65536.0f / 360.0f)) & 65535) * (360.0f / 65536.0f))
#define DotProduct(a,b) ((a)[0]*(b)[0]+(a)[1]*(b)[1]+(a)[2]*(b)[2])
#define VectorClear(a) ((a)[0]=(a)[1]=(a)[2]=0)
#define VectorSubtract(a,b,c) ((c)[0]=(a)[0]-(b)[0],(c)[1]=(a)[1]-(b)[1],(c)[2]=(a)[2]-(b)[2])
#define VectorAdd(a,b,c) ((c)[0]=(a)[0]+(b)[0],(c)[1]=(a)[1]+(b)[1],(c)[2]=(a)[2]+(b)[2])
#define VectorCopy(a,b) ((b)[0]=(a)[0],(b)[1]=(a)[1],(b)[2]=(a)[2])
#define VectorLength(a) (sqrt(DotProduct(a, a)))
#define VectorMA(a, scale, b, c) ((c)[0] = (a)[0] + (scale) * (b)[0],(c)[1] = (a)[1] + (scale) * (b)[1],(c)[2] = (a)[2] + (scale) * (b)[2])
#define CrossProduct(a,b,c) ((c)[0]=(a)[1]*(b)[2]-(a)[2]*(b)[1],(c)[1]=(a)[2]*(b)[0]-(a)[0]*(b)[2],(c)[2]=(a)[0]*(b)[1]-(a)[1]*(b)[0])
#define VectorScale(in, scale, out) ((out)[0] = (in)[0] * (scale),(out)[1] = (in)[1] * (scale),(out)[2] = (in)[2] * (scale))

float VectorNormalize (vec3_t v);		// returns vector length
void AngleVectors (const vec3_t angles, vec3_t forward, vec3_t right, vec3_t up);
int BoxOnPlaneSide (vec3_t emins, vec3_t emaxs, struct mplane_s *plane);

#define BOX_ON_PLANE_SIDE(emins, emaxs, p)	\
	(((p)->type < 3)?						\
	(										\
		((p)->dist <= (emins)[(p)->type])?	\
			1								\
		:									\
		(									\
			((p)->dist >= (emaxs)[(p)->type])?\
				2							\
			:								\
				3							\
		)									\
	)										\
	:										\
		BoxOnPlaneSide( (emins), (emaxs), (p)))