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/* Copyright (c) 1992 The Geometry Center; University of Minnesota
1300 South Second Street; Minneapolis, MN 55454, USA;
This file is part of geomview/OOGL. geomview/OOGL is free software;
you can redistribute it and/or modify it only under the terms given in
the file COPYING, which you should have received along with this file.
This and other related software may be obtained via anonymous ftp from
geom.umn.edu; email: software@geom.umn.edu. */
static char *copyright = "Copyright (C) 1992 The Geometry Center";
/* Authors: Charlie Gunn, Pat Hanrahan, Stuart Levy, Tamara Munzner, Mark Phillips, Celeste Fowler */
/*
** point3.c - 3D vector arithmetic module.
**
** pat hanrahan
**
*/
# include <math.h>
# include "tolerance.h"
# include "point3.h"
# include "transform3.h"
Point3 Pt3Origin = { 0., 0., 0. };
/* print vector */
void
Pt3Print( const Point3 *v )
{
/* Only works if Pt3Coord is a float */
printf("[%g %g %g]\n", v->x, v->y, v->z);
}
void
Pt3From(Point3 *v, double x, double y, double z)
{
v->x = x;
v->y = y;
v->z = z;
}
/* v2 = v1 */
void
Pt3Copy( const Point3 *v1, Point3 *v2 )
{
v2->x = v1->x;
v2->y = v1->y;
v2->z = v1->z;
}
/* v3 = v1 + v2 */
void
Pt3Add( const Point3 *v1, const Point3 *v2, Point3 *v3 )
{
v3->x = v1->x + v2->x;
v3->y = v1->y + v2->y;
v3->z = v1->z + v2->z;
}
/* v3 = v1 - v2 */
void
Pt3Sub( const Point3 *v1, const Point3 *v2, Point3 *v3)
{
v3->x = v1->x - v2->x;
v3->y = v1->y - v2->y;
v3->z = v1->z - v2->z;
}
/* v2 = s * v1 */
void
Pt3Mul( double s, const Point3 *v1, Point3 *v2 )
{
v2->x = s*v1->x;
v2->y = s*v1->y;
v2->z = s*v1->z;
}
/* v1 . v2 */
Pt3Coord
Pt3Dot( const Point3 *v1, const Point3 *v2 )
{
return v1->x*v2->x+v1->y*v2->y+v1->z*v2->z;
}
/* v3 = v1 x v2 */
void
Pt3Cross( const Point3 *v1, const Point3 *v2, Point3 *v3 )
{
v3->x = v1->y*v2->z-v1->z*v2->y;
v3->y = v1->z*v2->x-v1->x*v2->z;
v3->z = v1->x*v2->y-v1->y*v2->x;
}
/* v1 . (v2 x v3) */
Pt3Coord
Pt3TripleDot( const Point3 *v1, const Point3 *v2, const Point3 *v3 )
{
return v1->x*(v2->y*v3->z-v2->z*v3->y)
+ v1->y*(v2->z*v3->x-v2->x*v3->z)
+ v1->z*(v2->x*v3->y-v2->y*v3->x);
}
/* v4 = (v1 x v2) x v3 */
void
Pt3TripleCross( const Point3 *v1, const Point3 *v2, const Point3 *v3, Point3 *v4 )
{
Point3 v;
Pt3Cross( v1, v2, &v );
Pt3Cross( &v, v3, v4 );
}
Pt3Coord
Pt3Length( const Point3 *v )
{
return sqrt( v->x*v->x + v->y*v->y + v->z*v->z );
}
Pt3Coord
Pt3Distance( const Point3 *v1, const Point3 *v2 )
{
Point3 v12;
Pt3Sub(v1,v2,&v12);
return Pt3Length(&v12);
}
Pt3Coord
Pt3Angle( const Point3 *v1, const Point3 *v2 )
{
return(acos(Pt3Dot(v1, v2) / (Pt3Length(v1) * Pt3Length(v2))));
}
void
Pt3Unit( Point3 *v )
{
Pt3Coord len;
len = Pt3Length(v);
if( len != 0. && len != 1. )
Pt3Mul( 1./len, v, v );
}
/*
* lerp - linear interpolation
*
* v3 = (1-t)*v1 + t*v2
*/
void
Pt3Lerp( double t, const Point3 *v1, const Point3 *v2, Point3 *v3 )
{
v3->x = (1.-t)*v1->x + t*v2->x;
v3->y = (1.-t)*v1->y + t*v2->y;
v3->z = (1.-t)*v1->z + t*v2->z;
}
void
Pt3Comb( double t1, const Point3 *v1, double t2, const Point3 *v2, Point3 *v3 )
{
v3->x = t1*v1->x + t2*v2->x;
v3->y = t1*v1->y + t2*v2->y;
v3->z = t1*v1->z + t2*v2->z;
}
/* vectors equal */
int
Pt3Equal( const Point3 *v1, const Point3 *v2 )
{
Pt3Coord v;
v = Pt3Distance(v1, v2);
return fz(v);
}
/* parallel vectors */
int
Pt3Parallel( const Point3 *v1, const Point3 *v2 )
{
Point3 v3;
Pt3Coord v;
Pt3Cross(v1,v2,&v3);
v=Pt3Length(&v3);
return fz(v);
}
/* perpendicular vectors */
int
Pt3Perpendicular( const Point3 *v1, const Point3 *v2 )
{
Pt3Coord v;
v=Pt3Dot(v1,v2);
return fz(v);
}
void
Pt3Transform( T, p1, p2 )
Transform3 T;
Point3 *p1, *p2;
{
register Pt3Coord x, y, z, w;
x = p1->x;
y = p1->y;
z = p1->z;
w = (T[X][W]*x + T[Y][W]*y + T[Z][W]*z + T[W][W]);
if(w != 1.0) {
w = 1.0 / w;
p2->x = w * (x*T[X][X] + y*T[Y][X] + z*T[Z][X] + T[W][X]);
p2->y = w * (x*T[X][Y] + y*T[Y][Y] + z*T[Z][Y] + T[W][Y]);
p2->z = w * (x*T[X][Z] + y*T[Y][Z] + z*T[Z][Z] + T[W][Z]);
} else {
p2->x = x*T[X][X] + y*T[Y][X] + z*T[Z][X] + T[W][X];
p2->y = x*T[X][Y] + y*T[Y][Y] + z*T[Z][Y] + T[W][Y];
p2->z = x*T[X][Z] + y*T[Y][Z] + z*T[Z][Z] + T[W][Z];
}
}
void
Pt3TransformN( T, p1, p2, n )
Transform3 T;
Point3 *p1, *p2;
int n;
{
while( n-- )
Pt3Transform( T, p1++, p2++ );
}
void
NormalTransform( T, a, b )
Transform3 T;
Point3 *a, *b;
{
Pt3Transform(T, a, b);
b->x -= T[W][X];
b->y -= T[W][Y];
b->z -= T[W][Z];
Pt3Unit(b);
}
void
NormalTransformN( T, a, b, n )
Transform3 T;
Point3 *a, *b;
int n;
{
while ( n-- )
NormalTransform( T, a++, b++ );
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.