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: sh6count.c,v 1.2 2001-03-19 15:59:07 afr Exp $
45  *
46  */
47 
48 
49 #define SH6COUNT
50 
51 #include "sislP.h"
52 
53 
54 #if defined(SISLNEEDPROTOTYPES)
55 int
sh6count(SISLIntpt * pt,int * jstat)56       sh6count(SISLIntpt *pt,int *jstat)
57 #else
58 int sh6count(pt,jstat)
59    SISLIntpt *pt;
60    int       *jstat;
61 #endif
62 /*
63 *********************************************************************
64 *
65 *********************************************************************
66 *
67 * PURPOSE    : Given a main Intpt
68 *              return the number of points in the list (of
69 *              main points)
70 *              and determine whether it is open or closed
71 *              through *jstat. If the Intpt is not
72 *              in a unique list, say so.
73 *
74 *
75 * INPUT      : pt       - Pointer to the Intpt.
76 *              index    - Index specifying a list containing pt.
77 *              jstat    - Error flag.
78 *                         jstat = 0   => Successful. List is open.
79 *                         jstat = 1   => Successful. List is closed.
80 *                         jstat = 2   => pt is a junction pt.
81 *                         jstat = 3   => pt is isolated.
82 *                         jstat = -1  => Error in pt.
83 *                         jstat = -2  => List is inconsistent.
84 *
85 *
86 *
87 * METHOD     : 1. Traverse forwards from pt to one end of
88 *                 the list.
89 *              2. Then (unless list is closed) go to the
90 *                 other end of the list.
91 *
92 *
93 * REFERENCES :
94 *
95 * WRITTEN BY : Michael Floater, SI, Oslo, Norway. Sept. 91.
96 *
97 *********************************************************************
98 */
99 {
100    int       ki;      /* Counter.                        */
101    SISLIntpt *pt1, *pt2;  /* Neighbours of pt.           */
102    SISLIntpt *lastpt, *nowpt, *nextpt;
103 			 /* 3 adjacents pts in the list. */
104    int       kstat;   /* Status variable.                */
105 
106    *jstat = 0;
107    ki=1;
108 
109    if(pt == SISL_NULL) goto err1;
110    if(!sh6ismain(pt)) goto err1;
111 
112    sh6getnhbrs(pt,&pt1,&pt2,&kstat);
113    if(kstat < 0) goto err2; /* Bad list. */
114    if(kstat == 2)
115    {
116        *jstat = 2;
117        goto out;
118    }
119    if(kstat == 3)
120    {
121        *jstat = 3;
122        goto out;
123    }
124 
125 
126    /* Traverse in the first direction unless at the end. */
127 
128    nextpt=pt1;
129    nowpt=pt;
130    while(nextpt != SISL_NULL && nextpt != pt)
131    {
132        ki++;
133        lastpt=nowpt;
134        nowpt=nextpt;
135        sh6getother(nowpt,lastpt,&nextpt,&kstat);
136        if(kstat < 0) goto err2; /* Bad list. */
137    }
138 
139    /* Now if nextpt == pt the list is closed and we're finished. */
140 
141    if(nextpt == pt)
142    {
143        *jstat=1;
144        goto out;
145    }
146 
147    /* Otherwise traverse in the second direction. */
148 
149    nextpt=pt2;
150    nowpt=pt;
151    while(nextpt != SISL_NULL)
152    {
153        ki++;
154        lastpt=nowpt;
155        nowpt=nextpt;
156        sh6getother(nowpt,lastpt,&nextpt,&kstat);
157        if(kstat < 0) goto err2; /* Bad list. */
158    }
159 
160    goto out;
161 
162 err1:
163    /* Error. Error in pt or index. */
164    *jstat = -1;
165    s6err("sh6count",*jstat,0);
166    goto out;
167 
168 err2:
169    /* Error. List is inconsistent. */
170    *jstat = -2;
171    s6err("sh6count",*jstat,0);
172    goto out;
173 
174    out :
175       return ki;
176 }
177