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: s1436.c,v 1.2 2001-03-19 15:58:49 afr Exp $
45 *
46 */
47
48
49 #define S1436
50
51 #include "sislP.h"
52
53 #if defined(SISLNEEDPROTOTYPES)
54 void
s1436(SISLSurf * ps1,double apar,SISLCurve ** rcurve,int * jstat)55 s1436(SISLSurf *ps1,double apar,SISLCurve **rcurve,int *jstat)
56 #else
57 void s1436(ps1,apar,rcurve,jstat)
58 SISLSurf *ps1;
59 double apar;
60 SISLCurve **rcurve;
61 int *jstat;
62 #endif
63 /*
64 *********************************************************************
65 *
66 *********************************************************************
67 *
68 * PURPOSE : Make constant parameter curve in the surface. The
69 * constant parameter value used is apar and is in the
70 * second parameter direction.
71 *
72 *
73 *
74 * INPUT : ps1 - Surface.
75 * apar - Parameter value to use whe picking out constant
76 * parameter curve in second parameter direction.
77 *
78 *
79 *
80 * OUTPUT : rcurve - Constant parameter curve.
81 * jstat - status messages
82 * > 0 : warning
83 * = 0 : ok
84 * < 0 : error
85 *
86 *
87 * METHOD : The surface is treated as a (ps1->idim*ps1->in1)-
88 * dimensional curve with ps1->in2 vertices. The value
89 * of this curve at apar is calculated. This value is
90 * then viewed as the vertices of a (ps1->idim)-dimensional
91 * curve. The curve with these vertices and the knot-vector
92 * ps1->in2 is the curve we are looking for.
93 *
94 *
95 * REFERENCES :
96 *
97 *-
98 * CALLS : s1221 - Evaluate curve in given parameter value.
99 * newCurve - Create and initialize new curve.
100 *
101 * WRITTEN BY : Vibeke Skytt, SI, 88-11.
102 * REWISED BY : Per Evensen, SI, 89-3; Prepared for rational description.
103 * REWISED BY : Per Evensen, SI, 90-9; Corrected arguments in last call to newCurve.
104 * MODIFIED BY : Mike Floater, SI, 91-01; Use rcoef instead of ecoef if rational.
105 *
106 *********************************************************************
107 */
108 {
109 int kstat = 0; /* Local status variable. */
110 int kpos = 0; /* Position of error. */
111 int kder = 0; /* Number of derivatives of curve to evalutate. */
112 int kleft = 0; /* Parameter used in evaluation of curve. */
113 int kind = 0; /* Kind of curve
114 = 1 : Polynomial B-spline curve.
115 = 2 : Rational B-spline curve.
116 = 3 : Polynomial Bezier curve.
117 = 4 : Rational Bezier curve. */
118 int kdim;
119 double *scoef; /* Pointer to vertices. */
120 double *scurve = SISL_NULL; /* Vertices of constant parameter curve. */
121 SISLCurve *qc = SISL_NULL; /* Pointer to intermediate curve. */
122
123 /* Prepare for rational description. */
124
125 kdim = ps1->idim;
126 kind = ps1->ikind;
127 if(ps1->ikind == 2 || ps1->ikind == 4)
128 {
129 scoef = ps1->rcoef;
130 kdim = kdim+1;
131 }
132 else
133 {
134 scoef = ps1->ecoef;
135 }
136
137 /* Create the curve describing the surface as a curve. */
138
139 if ((qc = newCurve(ps1->in2,ps1->ik2,ps1->et2,scoef,1,
140 ps1->in1*kdim,0)) == SISL_NULL) goto err101;
141
142 /* Allocate space for value of curve. */
143
144 if ((scurve = newarray(ps1->in1*kdim,double)) == SISL_NULL) goto err101;
145
146 /* Evaluate this curve at given parameter value. */
147
148 s1221(qc,kder,apar,&kleft,scurve,&kstat);
149 if (kstat < 0) goto error;
150
151 /* Create constant parameter curve. */
152
153 *rcurve = newCurve(ps1->in1,ps1->ik1,ps1->et1,scurve,kind,ps1->idim,1);
154 if (*rcurve == SISL_NULL) goto err101;
155
156 /* Set periodicity flag. */
157
158 (*rcurve)->cuopen = ps1->cuopen_1;
159
160 /* Curve picked. */
161
162 *jstat = 0;
163 goto out;
164
165 /* Error in space allocation. */
166
167 err101: *jstat = -101;
168 s6err("s1436",*jstat,kpos);
169 goto out;
170
171 /* Error in lower level routine. */
172
173 error : *jstat = kstat;
174 s6err("s1436",*jstat,kpos);
175 goto out;
176
177 out:
178
179 /* Free space occupied by local arrays. */
180
181 if (scurve != SISL_NULL) freearray(scurve);
182 if (qc != SISL_NULL) freeCurve(qc);
183
184 return;
185 }
186