lib/Generate/trimesh_geompk.c

   1 /*
   2     This file is part of the FElt finite element analysis package.
   3     Copyright (C) 1993 Jason I. Gobat and Darren C. Atkinson
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18 */
  19
  20 /****************************************************************************
  21  *
  22  * File:        triangle.c
  23  *
  24  ***************************************************************************/
  25
  26 # include <math.h>
  27 # include <stdio.h>
  28 # include "allocate.h"
  29 # include "error.h"
  30 # include "fe.h"
  31 # include "objects.h"
  32 # include "mesh.h"
  33
  34 typedef double dbl_pair [2];
  35 typedef int    triple_int [3];
  36
  37 void geompk_ ( );
  38
  39 /****************************************************************************
  40  *
  41  * Function:    GenerateTriMesh
  42  *
  43  * Description: a procedure to interface to Geompack and generate a mesh
  44  *              of triangular elements.
  45  *
  46  ****************************************************************************/
  47
  48 unsigned GenerateTriMesh (trimesh,element,node,numelts,numnodes,bnode,belement)
  49    TriMesh      trimesh;
  50    Element      **element;
  51    Node         **node;
  52    unsigned     *numelts;
  53    unsigned     *numnodes;
  54    unsigned     bnode;
  55    unsigned     belement;
  56 {
  57    unsigned     i,j;
  58    unsigned     count;
  59    int          ne, nn;
  60    int          nvertices,
  61                 *nvbc;
  62    double       (*vcl) [2];
  63    int          (*eln) [3];
  64    int          status;
  65
  66    nvertices = 0;
  67
  68    if (trimesh -> numcurves <= 0) {
  69       error ("must have at least a boundary curve to generate a TriMesh");
  70       return 1;
  71    }
  72
  73    if (trimesh -> definition -> numnodes != 3) {
  74       error ("TriMesh generation requires three node elements");
  75       return 1;
  76    }
  77
  78    vcl = Allocate (dbl_pair, 4*trimesh -> max);
  79    eln = Allocate (triple_int, 2*trimesh -> max);
  80
  81    if (vcl == NULL || eln == NULL)
  82       Fatal ("allocation error creating TriMesh");
  83
  84    nvbc = Allocate (int, trimesh -> numcurves);
  85
  86    if (nvbc == NULL)
  87       Fatal ("allocation error creating TriMesh");
  88
  89    count = 0;
  90
  91    for (i = 0 ; i < trimesh -> numcurves ; i++) {
  92       nvertices += trimesh -> curves [i] -> numvc;
  93       nvbc [i] = trimesh -> curves [i] -> numvc;
  94
  95       for (j = 0 ; j < trimesh -> curves[i] -> numvc ; j++) {
  96          vcl [count][0] = trimesh -> curves[i] -> vcl[j][0];
  97          vcl [count][1] = trimesh -> curves[i] -> vcl[j][1];
  98          count++;
  99       }
 100    }
 101
 102    if (nvertices <= 0) {
 103       error ("nothing to generate");
 104       Deallocate (vcl);
 105       Deallocate (eln);
 106
 107       return 1;
 108    }
 109
 110
 111    geompk_ (&(trimesh -> tolin), &(trimesh -> angspc),
 112             &(trimesh -> angtol), &(trimesh -> kappa),
 113             &(trimesh -> dmin), &(trimesh -> min),
 114             &(trimesh -> max), &nvertices, &(trimesh -> numcurves),
 115             nvbc, vcl, eln, &ne, &status);
 116
 117    if (status) {
 118       error ("Geompack error code #%d in TriMesh generation",status);
 119       return 1;
 120    }
 121
 122    if (ne <= 0) {
 123       error ("nothing to generate");
 124       return 1;
 125    }
 126
 127         /*
 128          * allocate some memory to hold everything that we will generate
 129          */
 130
 131    nn = nvertices;
 132
 133    if (nn <= 0) {
 134       error ("nothing to generate");
 135       return 1;
 136    }
 137
 138    if (!(*node = Allocate(Node, nn)))
 139       Fatal ("allocation error in TriMesh generation");
 140
 141    UnitOffset (*node);
 142
 143    for (i = 1 ; i <= nn ; i++) {
 144       if (!((*node) [i] = CreateNode (0)))
 145          Fatal ("allocation error in TriMesh generation");
 146    }
 147
 148    if (!(*element = Allocate(Element, ne)))
 149       Fatal ("allocation error in TriMesh generation");
 150
 151    UnitOffset (*element);
 152
 153    for (i = 1 ; i <= ne ; i++) {
 154       if (!((*element) [i] = CreateElement (0, trimesh -> definition)))
 155          Fatal ("allocation error in TriMesh generation");
 156    }
 157
 158         /*
 159          * generate all the nodes
 160          */
 161
 162    for (i = 1 ; i <= nn ; i++) {
 163
 164       (*node) [i] -> number = i + bnode;
 165       (*node) [i] -> x = vcl [i-1][0];
 166       (*node) [i] -> y = vcl [i-1][1];
 167       (*node) [i] -> z = 0;
 168
 169    }
 170
 171         /*
 172          * attach all the elements to the nodes
 173          */
 174
 175    for (i = 1 ; i <= ne ; i++) {
 176
 177       (*element) [i] -> number = i + belement;
 178       (*element) [i] -> node [1] = (*node) [eln[i-1][0]];
 179       (*element) [i] -> node [2] = (*node) [eln[i-1][1]];
 180       (*element) [i] -> node [3] = (*node) [eln[i-1][2]];
 181
 182    }
 183
 184    *numnodes = nn;
 185    *numelts  = ne;
 186
 187    Deallocate (vcl);
 188    Deallocate (eln);
 189
 190    return 0;
 191 }