src/common/fvect.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#endif
/*
 *  fvect.c - routines for floating-point vector calculations
 */

/* ====================================================================
 * The Radiance Software License, Version 1.0
 *
 * Copyright (c) 1990 - 2002 The Regents of the University of California,
 * through Lawrence Berkeley National Laboratory.   All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *         notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *           if any, must include the following acknowledgment:
 *             "This product includes Radiance software
 *                 (http://radsite.lbl.gov/)
 *                 developed by the Lawrence Berkeley National Laboratory
 *               (http://www.lbl.gov/)."
 *       Alternately, this acknowledgment may appear in the software itself,
 *       if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
 *       and "The Regents of the University of California" must
 *       not be used to endorse or promote products derived from this
 *       software without prior written permission. For written
 *       permission, please contact [email protected].
 *
 * 5. Products derived from this software may not be called "Radiance",
 *       nor may "Radiance" appear in their name, without prior written
 *       permission of Lawrence Berkeley National Laboratory.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Lawrence Berkeley National Laboratory.   For more
 * information on Lawrence Berkeley National Laboratory, please see
 * <http://www.lbl.gov/>.
 */

#include  <math.h>
#include  "fvect.h"


double
fdot(v1, v2)                    /* return the dot product of two vectors */
register FVECT  v1, v2;
{
        return(DOT(v1,v2));
}


double
dist2(p1, p2)                   /* return square of distance between points */
register FVECT  p1, p2;
{
        FVECT  delta;

        delta[0] = p2[0] - p1[0];
        delta[1] = p2[1] - p1[1];
        delta[2] = p2[2] - p1[2];

        return(DOT(delta, delta));
}


double
dist2line(p, ep1, ep2)          /* return square of distance to line */
FVECT  p;               /* the point */
FVECT  ep1, ep2;        /* points on the line */
{
        register double  d, d1, d2;

        d = dist2(ep1, ep2);
        d1 = dist2(ep1, p);
        d2 = d + d1 - dist2(ep2, p);

        return(d1 - 0.25*d2*d2/d);
}


double
dist2lseg(p, ep1, ep2)          /* return square of distance to line segment */
FVECT  p;               /* the point */
FVECT  ep1, ep2;        /* the end points */
{
        register double  d, d1, d2;

        d = dist2(ep1, ep2);
        d1 = dist2(ep1, p);
        d2 = dist2(ep2, p);

        if (d2 > d1) {                  /* check if past endpoints */
                if (d2 - d1 > d)
                        return(d1);
        } else {
                if (d1 - d2 > d)
                        return(d2);
        }
        d2 = d + d1 - d2;

        return(d1 - 0.25*d2*d2/d);      /* distance to line */
}


void
fcross(vres, v1, v2)            /* vres = v1 X v2 */
register FVECT  vres, v1, v2;
{
        vres[0] = v1[1]*v2[2] - v1[2]*v2[1];
        vres[1] = v1[2]*v2[0] - v1[0]*v2[2];
        vres[2] = v1[0]*v2[1] - v1[1]*v2[0];
}


void
fvsum(vres, v0, v1, f)          /* vres = v0 + f*v1 */
register FVECT  vres, v0, v1;
register double  f;
{
        vres[0] = v0[0] + f*v1[0];
        vres[1] = v0[1] + f*v1[1];
        vres[2] = v0[2] + f*v1[2];
}


double
normalize(v)                    /* normalize a vector, return old magnitude */
register FVECT  v;
{
        register double  len, d;
        
        d = DOT(v, v);
        
        if (d <= 0.0)
                return(0.0);
        
        if (d <= 1.0+FTINY && d >= 1.0-FTINY)
                len = 0.5 + 0.5*d;      /* first order approximation */
        else
                len = sqrt(d);

        v[0] *= d = 1.0/len;
        v[1] *= d;
        v[2] *= d;

        return(len);
}


void
spinvector(vres, vorig, vnorm, theta)   /* rotate vector around normal */
FVECT  vres, vorig, vnorm;
double  theta;
{
        double  sint, cost, normprod;
        FVECT  vperp;
        register int  i;
        
        if (theta == 0.0) {
                if (vres != vorig)
                        VCOPY(vres, vorig);
                return;
        }
        cost = cos(theta);
        sint = sin(theta);
        normprod = DOT(vorig, vnorm)*(1.-cost);
        fcross(vperp, vnorm, vorig);
        for (i = 0; i < 3; i++)
                vres[i] = vorig[i]*cost + vnorm[i]*normprod + vperp[i]*sint;
}
Revision:	2.6
Committed:	Sat Feb 22 02:07:22 2003 UTC (21 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.5:	+61 -6 lines
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	Content
1	#ifndef lint
2	static const char RCSid[] = "$Id$";
3	#endif
4	/*
5	* fvect.c - routines for floating-point vector calculations
6	*/
7
8	/* ====================================================================
9	* The Radiance Software License, Version 1.0
10	*
11	* Copyright (c) 1990 - 2002 The Regents of the University of California,
12	* through Lawrence Berkeley National Laboratory. All rights reserved.
13	*
14	* Redistribution and use in source and binary forms, with or without
15	* modification, are permitted provided that the following conditions
16	* are met:
17	*
18	* 1. Redistributions of source code must retain the above copyright
19	* notice, this list of conditions and the following disclaimer.
20	*
21	* 2. Redistributions in binary form must reproduce the above copyright
22	* notice, this list of conditions and the following disclaimer in
23	* the documentation and/or other materials provided with the
24	* distribution.
25	*
26	* 3. The end-user documentation included with the redistribution,
27	* if any, must include the following acknowledgment:
28	* "This product includes Radiance software
29	* (http://radsite.lbl.gov/)
30	* developed by the Lawrence Berkeley National Laboratory
31	* (http://www.lbl.gov/)."
32	* Alternately, this acknowledgment may appear in the software itself,
33	* if and wherever such third-party acknowledgments normally appear.
34	*
35	* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
36	* and "The Regents of the University of California" must
37	* not be used to endorse or promote products derived from this
38	* software without prior written permission. For written
39	* permission, please contact [email protected].
40	*
41	* 5. Products derived from this software may not be called "Radiance",
42	* nor may "Radiance" appear in their name, without prior written
43	* permission of Lawrence Berkeley National Laboratory.
44	*
45	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
46	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
47	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
48	* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
49	* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
51	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
52	* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
53	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
54	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
55	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56	* SUCH DAMAGE.
57	* ====================================================================
58	*
59	* This software consists of voluntary contributions made by many
60	* individuals on behalf of Lawrence Berkeley National Laboratory. For more
61	* information on Lawrence Berkeley National Laboratory, please see
62	* <http://www.lbl.gov/>.
63	*/
64
65	#include <math.h>
66	#include "fvect.h"
67
68
69	double
70	fdot(v1, v2) /* return the dot product of two vectors */
71	register FVECT v1, v2;
72	{
73	return(DOT(v1,v2));
74	}
75
76
77	double
78	dist2(p1, p2) /* return square of distance between points */
79	register FVECT p1, p2;
80	{
81	FVECT delta;
82
83	delta[0] = p2[0] - p1[0];
84	delta[1] = p2[1] - p1[1];
85	delta[2] = p2[2] - p1[2];
86
87	return(DOT(delta, delta));
88	}
89
90
91	double
92	dist2line(p, ep1, ep2) /* return square of distance to line */
93	FVECT p; /* the point */
94	FVECT ep1, ep2; /* points on the line */
95	{
96	register double d, d1, d2;
97
98	d = dist2(ep1, ep2);
99	d1 = dist2(ep1, p);
100	d2 = d + d1 - dist2(ep2, p);
101
102	return(d1 - 0.25d2d2/d);
103	}
104
105
106	double
107	dist2lseg(p, ep1, ep2) /* return square of distance to line segment */
108	FVECT p; /* the point */
109	FVECT ep1, ep2; /* the end points */
110	{
111	register double d, d1, d2;
112
113	d = dist2(ep1, ep2);
114	d1 = dist2(ep1, p);
115	d2 = dist2(ep2, p);
116
117	if (d2 > d1) { /* check if past endpoints */
118	if (d2 - d1 > d)
119	return(d1);
120	} else {
121	if (d1 - d2 > d)
122	return(d2);
123	}
124	d2 = d + d1 - d2;
125
126	return(d1 - 0.25d2d2/d); /* distance to line */
127	}
128
129
130	void
131	fcross(vres, v1, v2) /* vres = v1 X v2 */
132	register FVECT vres, v1, v2;
133	{
134	vres[0] = v1[1]v2[2] - v1[2]v2[1];
135	vres[1] = v1[2]v2[0] - v1[0]v2[2];
136	vres[2] = v1[0]v2[1] - v1[1]v2[0];
137	}
138
139
140	void
141	fvsum(vres, v0, v1, f) /* vres = v0 + fv1 /
142	register FVECT vres, v0, v1;
143	register double f;
144	{
145	vres[0] = v0[0] + f*v1[0];
146	vres[1] = v0[1] + f*v1[1];
147	vres[2] = v0[2] + f*v1[2];
148	}
149
150
151	double
152	normalize(v) /* normalize a vector, return old magnitude */
153	register FVECT v;
154	{
155	register double len, d;
156
157	d = DOT(v, v);
158
159	if (d <= 0.0)
160	return(0.0);
161
162	if (d <= 1.0+FTINY && d >= 1.0-FTINY)
163	len = 0.5 + 0.5d; / first order approximation */
164	else
165	len = sqrt(d);
166
167	v[0] *= d = 1.0/len;
168	v[1] *= d;
169	v[2] *= d;
170
171	return(len);
172	}
173
174
175	void
176	spinvector(vres, vorig, vnorm, theta) /* rotate vector around normal */
177	FVECT vres, vorig, vnorm;
178	double theta;
179	{
180	double sint, cost, normprod;
181	FVECT vperp;
182	register int i;
183
184	if (theta == 0.0) {
185	if (vres != vorig)
186	VCOPY(vres, vorig);
187	return;
188	}
189	cost = cos(theta);
190	sint = sin(theta);
191	normprod = DOT(vorig, vnorm)*(1.-cost);
192	fcross(vperp, vnorm, vorig);
193	for (i = 0; i < 3; i++)
194	vres[i] = vorig[i]cost + vnorm[i]normprod + vperp[i]*sint;
195	}