ref: bea7b7bf8ccbc2bc41906517079e76fcfb31cb5a
dir: /common/mathlib.c/
/*
===========================================================================
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
===========================================================================
*/
// mathlib.c -- math primitives
#include "cmdlib.h"
#include "mathlib.h"
#ifdef _WIN32
//Improve floating-point consistency.
//without this option weird floating point issues occur
#pragma optimize( "p", on )
#endif
vec3_t vec3_origin = {0,0,0};
/*
** NormalToLatLong
**
** We use two byte encoded normals in some space critical applications.
** Lat = 0 at (1,0,0) to 360 (-1,0,0), encoded in 8-bit sine table format
** Lng = 0 at (0,0,1) to 180 (0,0,-1), encoded in 8-bit sine table format
**
*/
void NormalToLatLong( const vec3_t normal, byte bytes[2] ) {
// check for singularities
if ( normal[0] == 0 && normal[1] == 0 ) {
if ( normal[2] > 0 ) {
bytes[0] = 0;
bytes[1] = 0; // lat = 0, long = 0
} else {
bytes[0] = 128;
bytes[1] = 0; // lat = 0, long = 128
}
} else {
int a, b;
a = RAD2DEG( atan2( normal[1], normal[0] ) ) * (255.0f / 360.0f );
a &= 0xff;
b = RAD2DEG( acos( normal[2] ) ) * ( 255.0f / 360.0f );
b &= 0xff;
bytes[0] = b; // longitude
bytes[1] = a; // lattitude
}
}
/*
=====================
PlaneFromPoints
Returns false if the triangle is degenrate.
The normal will point out of the clock for clockwise ordered points
=====================
*/
qboolean PlaneFromPoints( vec4_t plane, const vec3_t a, const vec3_t b, const vec3_t c ) {
vec3_t d1, d2;
VectorSubtract( b, a, d1 );
VectorSubtract( c, a, d2 );
CrossProduct( d2, d1, plane );
if ( VectorNormalize( plane, plane ) == 0 ) {
return qfalse;
}
plane[3] = DotProduct( a, plane );
return qtrue;
}
/*
================
MakeNormalVectors
Given a normalized forward vector, create two
other perpendicular vectors
================
*/
void MakeNormalVectors (vec3_t forward, vec3_t right, vec3_t up)
{
float d;
// this rotate and negate guarantees a vector
// not colinear with the original
right[1] = -forward[0];
right[2] = forward[1];
right[0] = forward[2];
d = DotProduct (right, forward);
VectorMA (right, -d, forward, right);
VectorNormalize (right, right);
CrossProduct (right, forward, up);
}
void Vec10Copy( vec_t *in, vec_t *out ) {
out[0] = in[0];
out[1] = in[1];
out[2] = in[2];
out[3] = in[3];
out[4] = in[4];
out[5] = in[5];
out[6] = in[6];
out[7] = in[7];
out[8] = in[8];
out[9] = in[9];
}
void VectorRotate3x3( vec3_t v, float r[3][3], vec3_t d )
{
d[0] = v[0] * r[0][0] + v[1] * r[1][0] + v[2] * r[2][0];
d[1] = v[0] * r[0][1] + v[1] * r[1][1] + v[2] * r[2][1];
d[2] = v[0] * r[0][2] + v[1] * r[1][2] + v[2] * r[2][2];
}
double VectorLength( const vec3_t v ) {
int i;
double length;
length = 0;
for (i=0 ; i< 3 ; i++)
length += v[i]*v[i];
length = sqrt (length); // FIXME
return length;
}
qboolean VectorCompare( const vec3_t v1, const vec3_t v2 ) {
int i;
for (i=0 ; i<3 ; i++)
if (fabs(v1[i]-v2[i]) > EQUAL_EPSILON)
return qfalse;
return qtrue;
}
vec_t Q_rint (vec_t in)
{
return floor (in + 0.5);
}
void VectorMA( const vec3_t va, double scale, const vec3_t vb, vec3_t vc ) {
vc[0] = va[0] + scale*vb[0];
vc[1] = va[1] + scale*vb[1];
vc[2] = va[2] + scale*vb[2];
}
void CrossProduct( const vec3_t v1, const vec3_t v2, vec3_t cross ) {
cross[0] = v1[1]*v2[2] - v1[2]*v2[1];
cross[1] = v1[2]*v2[0] - v1[0]*v2[2];
cross[2] = v1[0]*v2[1] - v1[1]*v2[0];
}
vec_t _DotProduct (vec3_t v1, vec3_t v2)
{
return v1[0]*v2[0] + v1[1]*v2[1] + v1[2]*v2[2];
}
void _VectorSubtract (vec3_t va, vec3_t vb, vec3_t out)
{
out[0] = va[0]-vb[0];
out[1] = va[1]-vb[1];
out[2] = va[2]-vb[2];
}
void _VectorAdd (vec3_t va, vec3_t vb, vec3_t out)
{
out[0] = va[0]+vb[0];
out[1] = va[1]+vb[1];
out[2] = va[2]+vb[2];
}
void _VectorCopy (vec3_t in, vec3_t out)
{
out[0] = in[0];
out[1] = in[1];
out[2] = in[2];
}
void _VectorScale (vec3_t v, vec_t scale, vec3_t out)
{
out[0] = v[0] * scale;
out[1] = v[1] * scale;
out[2] = v[2] * scale;
}
vec_t VectorNormalize( const vec3_t in, vec3_t out ) {
vec_t length, ilength;
length = sqrt (in[0]*in[0] + in[1]*in[1] + in[2]*in[2]);
if (length == 0)
{
VectorClear (out);
return 0;
}
ilength = 1.0/length;
out[0] = in[0]*ilength;
out[1] = in[1]*ilength;
out[2] = in[2]*ilength;
return length;
}
vec_t ColorNormalize( const vec3_t in, vec3_t out ) {
float max, scale;
max = in[0];
if (in[1] > max)
max = in[1];
if (in[2] > max)
max = in[2];
if (max == 0) {
out[0] = out[1] = out[2] = 1.0;
return 0;
}
scale = 1.0 / max;
VectorScale (in, scale, out);
return max;
}
void VectorInverse (vec3_t v)
{
v[0] = -v[0];
v[1] = -v[1];
v[2] = -v[2];
}
void ClearBounds (vec3_t mins, vec3_t maxs)
{
mins[0] = mins[1] = mins[2] = 99999;
maxs[0] = maxs[1] = maxs[2] = -99999;
}
void AddPointToBounds( const vec3_t v, vec3_t mins, vec3_t maxs ) {
int i;
vec_t val;
for (i=0 ; i<3 ; i++)
{
val = v[i];
if (val < mins[i])
mins[i] = val;
if (val > maxs[i])
maxs[i] = val;
}
}
/*
=================
PlaneTypeForNormal
=================
*/
int PlaneTypeForNormal (vec3_t normal) {
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;
return PLANE_NON_AXIAL;
}
/*
================
MatrixMultiply
================
*/
void MatrixMultiply(float in1[3][3], float in2[3][3], float out[3][3]) {
out[0][0] = in1[0][0] * in2[0][0] + in1[0][1] * in2[1][0] +
in1[0][2] * in2[2][0];
out[0][1] = in1[0][0] * in2[0][1] + in1[0][1] * in2[1][1] +
in1[0][2] * in2[2][1];
out[0][2] = in1[0][0] * in2[0][2] + in1[0][1] * in2[1][2] +
in1[0][2] * in2[2][2];
out[1][0] = in1[1][0] * in2[0][0] + in1[1][1] * in2[1][0] +
in1[1][2] * in2[2][0];
out[1][1] = in1[1][0] * in2[0][1] + in1[1][1] * in2[1][1] +
in1[1][2] * in2[2][1];
out[1][2] = in1[1][0] * in2[0][2] + in1[1][1] * in2[1][2] +
in1[1][2] * in2[2][2];
out[2][0] = in1[2][0] * in2[0][0] + in1[2][1] * in2[1][0] +
in1[2][2] * in2[2][0];
out[2][1] = in1[2][0] * in2[0][1] + in1[2][1] * in2[1][1] +
in1[2][2] * in2[2][1];
out[2][2] = in1[2][0] * in2[0][2] + in1[2][1] * in2[1][2] +
in1[2][2] * in2[2][2];
}
void ProjectPointOnPlane( vec3_t dst, const vec3_t p, const vec3_t normal )
{
float d;
vec3_t n;
float inv_denom;
inv_denom = 1.0F / DotProduct( normal, normal );
d = DotProduct( normal, p ) * inv_denom;
n[0] = normal[0] * inv_denom;
n[1] = normal[1] * inv_denom;
n[2] = normal[2] * inv_denom;
dst[0] = p[0] - d * n[0];
dst[1] = p[1] - d * n[1];
dst[2] = p[2] - d * n[2];
}
/*
** assumes "src" is normalized
*/
void PerpendicularVector( vec3_t dst, const vec3_t src )
{
int pos;
int i;
float minelem = 1.0F;
vec3_t tempvec;
/*
** find the smallest magnitude axially aligned vector
*/
for ( pos = 0, i = 0; i < 3; i++ )
{
if ( fabs( src[i] ) < minelem )
{
pos = i;
minelem = fabs( src[i] );
}
}
tempvec[0] = tempvec[1] = tempvec[2] = 0.0F;
tempvec[pos] = 1.0F;
/*
** project the point onto the plane defined by src
*/
ProjectPointOnPlane( dst, tempvec, src );
/*
** normalize the result
*/
VectorNormalize( dst, dst );
}
/*
===============
RotatePointAroundVector
This is not implemented very well...
===============
*/
void RotatePointAroundVector( vec3_t dst, const vec3_t dir, const vec3_t point,
float degrees ) {
float m[3][3];
float im[3][3];
float zrot[3][3];
float tmpmat[3][3];
float rot[3][3];
int i;
vec3_t vr, vup, vf;
float rad;
vf[0] = dir[0];
vf[1] = dir[1];
vf[2] = dir[2];
PerpendicularVector( vr, dir );
CrossProduct( vr, vf, vup );
m[0][0] = vr[0];
m[1][0] = vr[1];
m[2][0] = vr[2];
m[0][1] = vup[0];
m[1][1] = vup[1];
m[2][1] = vup[2];
m[0][2] = vf[0];
m[1][2] = vf[1];
m[2][2] = vf[2];
memcpy( im, m, sizeof( im ) );
im[0][1] = m[1][0];
im[0][2] = m[2][0];
im[1][0] = m[0][1];
im[1][2] = m[2][1];
im[2][0] = m[0][2];
im[2][1] = m[1][2];
memset( zrot, 0, sizeof( zrot ) );
zrot[0][0] = zrot[1][1] = zrot[2][2] = 1.0F;
rad = DEG2RAD( degrees );
zrot[0][0] = cos( rad );
zrot[0][1] = sin( rad );
zrot[1][0] = -sin( rad );
zrot[1][1] = cos( rad );
MatrixMultiply( m, zrot, tmpmat );
MatrixMultiply( tmpmat, im, rot );
for ( i = 0; i < 3; i++ ) {
dst[i] = rot[i][0] * point[0] + rot[i][1] * point[1] + rot[i][2] * point[2];
}
}