1 /*
2  * Copyright (C) 1998, 2000-2007, 2010, 2011, 2012, 2013 SINTEF ICT,
3  * Applied Mathematics, Norway.
4  *
5  * Contact information: E-mail: tor.dokken@sintef.no
6  * SINTEF ICT, Department of Applied Mathematics,
7  * P.O. Box 124 Blindern,
8  * 0314 Oslo, Norway.
9  *
10  * This file is part of SISL.
11  *
12  * SISL is free software: you can redistribute it and/or modify
13  * it under the terms of the GNU Affero General Public License as
14  * published by the Free Software Foundation, either version 3 of the
15  * License, or (at your option) any later version.
16  *
17  * SISL is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU Affero General Public License for more details.
21  *
22  * You should have received a copy of the GNU Affero General Public
23  * License along with SISL. If not, see
24  * <http://www.gnu.org/licenses/>.
25  *
26  * In accordance with Section 7(b) of the GNU Affero General Public
27  * License, a covered work must retain the producer line in every data
28  * file that is created or manipulated using SISL.
29  *
30  * Other Usage
31  * You can be released from the requirements of the license by purchasing
32  * a commercial license. Buying such a license is mandatory as soon as you
33  * develop commercial activities involving the SISL library without
34  * disclosing the source code of your own applications.
35  *
36  * This file may be used in accordance with the terms contained in a
37  * written agreement between you and SINTEF ICT.
38  */
39 
40 #include "sisl-copyright.h"
41 
42 /*
43  *
44  * $Id: s1774.c,v 1.2 2001-03-19 15:58:53 afr Exp $
45  *
46  */
47 #define S1774
48 
49 #include "sislP.h"
50 
51 
52 #if defined(SISLNEEDPROTOTYPES)
53 void
s1774(SISLCurve * crv,double point[],int dim,double epsge,double start,double end,double guess,double * clpar,int * stat)54 s1774(SISLCurve *crv, double point[], int dim, double epsge,
55 	   double start, double end, double guess, double *clpar, int *stat)
56 #else
57 void s1774(crv, point, dim, epsge, start, end, guess, clpar, stat)
58      SISLCurve  *crv;
59      double point[];
60      int dim;
61      double epsge;
62      double start;
63      double end;
64      double guess;
65      double *clpar;
66      int    *stat;
67 #endif
68 /*
69 *********************************************************************
70 *
71 *********************************************************************
72 *
73 * PURPOSE    : Newton iteration on the distance function between
74 *              a curve and a point, to find a closest point or an
75 *              intersection point.
76 *              If a bad choice for the guess parameter is given in, the
77 *              iteration may end at a local, not global closest point.
78 *
79 *
80 * INPUT      : crv     - The curve in the closest point problem.
81 *              point   - The point in the closest point problem.
82 *              dim     - Dimension of the geometry.
83 *              epsge   - Geometrical resolution.
84 *              start   - Curve parameter giving the start of the search
85 *                        interval.
86 *              end     - Curve parameter giving the end of the search
87 *                        interval.
88 *              guess   - Curve guess parameter for the closest point
89 *                        iteration.
90 *
91 *
92 *
93 * OUTPUT     : clpar   - Resulting curve parameter from the iteration.
94 *              stat    - status messages
95 *                                = 2   : A minimum distanse found.
96 *                                = 1   : Intersection found.
97 *                                < 0   : error.
98 *
99 *
100 * METHOD     : Newton iteration.
101 *
102 *
103 * REFERENCES :
104 *
105 *
106 * WRITTEN BY : Johannes Kaasa, SINTEF, Aug 1995
107 *
108 *********************************************************************
109 */
110 {
111    int kpos = 0;             /* Error indicator. */
112    SISLPoint* ppoint = SISL_NULL; /* SISL point.      */
113 
114    /* Generate a SISL point. */
115 
116    ppoint = newPoint(point, dim, 0);
117 
118    /* Call s1771. */
119 
120    s1771(ppoint, crv, epsge, start, end, guess, clpar, stat);
121    if (*stat < 0) goto error;
122 
123    goto out;
124 
125    /* Error in lower level routine.  */
126 
127    error :
128    s6err("s1774", *stat, kpos);
129    goto out;
130 
131  out:
132     if (ppoint != SISL_NULL) freePoint(ppoint);
133 }
134 
135