# usecases/c/UsesCase_MEDmesh_4.c

    /*  This file is part of MED.
     *
     *  COPYRIGHT (C) 1999 - 2012  EDF R&D, CEA/DEN
     *  MED is free software: you can redistribute it and/or modify
     *  it under the terms of the GNU Lesser General Public License as published by
     *  the Free Software Foundation, either version 3 of the License, or
     *  (at your option) any later version.
     *
     *  MED is distributed in the hope that it will be useful,
     *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     *  GNU Lesser General Public License for more details.
     *
     *  You should have received a copy of the GNU Lesser General Public License
     *  along with MED.  If not, see <http://www.gnu.org/licenses/>.
     */

    /*
     *  How to create a structured mesh
     *
     *  Use case 4 :  write a 2D structured mesh (5x3 cartesian grid)
     */

    #include <med.h>
    #define MESGERR 1
    #include <med_utils.h>

    #include <string.h>

    int main (int argc, char **argv) {
      med_idt fid;
      const char meshname[MED_NAME_SIZE+1] = "2D structured mesh";
      const med_int spacedim = 2;
      const med_int meshdim = 2;
      const char axisname[2*MED_SNAME_SIZE+1] = "x               y               ";
      const char unitname[2*MED_SNAME_SIZE+1] = "cm              cm              ";
      med_int axis, size ;
      const med_float cooXaxis[5] = {1.,2.,3.,4.,5.};
      const med_float cooYaxis[3] = {1.,2.,3.};
      /*                    12345678901234561234567890123456123456789012345612345678901234561234567890123456123456789012345612345678901234561234567890123456 */
      const char cellsnames[8*MED_SNAME_SIZE+1] = "CELL_1          CELL_2          CELL_3          CELL_4          CELL_5          CELL_6          CELL_7          CELL_8          ";
      const med_int nquad4 = 8;
      int ret=-1;

      /* MED file creation */
      fid = MEDfileOpen("UsesCase_MEDmesh_4.med",MED_ACC_CREAT);
      if (fid < 0) {
        MESSAGE("ERROR : file creation ...");
        goto ERROR;
      }

      /* create the structured mesh in the MED file */
      if (MEDmeshCr(fid, meshname, spacedim, meshdim, MED_STRUCTURED_MESH,
                    "A 2D structured mesh","",MED_SORT_DTIT,
                    MED_CARTESIAN, axisname, unitname) < 0) {
        MESSAGE("ERROR : mesh creation ...");
        goto ERROR;
      }

      /* specify the grid type : MED_CARTESIAN_GRID */
       if (MEDmeshGridTypeWr(fid,meshname, MED_CARTESIAN_GRID) < 0) {
        MESSAGE("ERROR : write grid type ...");
        goto ERROR;
      }

       /* write axis "X" and "Y" coordinates */
       axis = 1;
       size = 5;
       if (MEDmeshGridIndexCoordinateWr(fid, meshname, MED_NO_DT, MED_NO_IT,0.0,
                                        axis, size, cooXaxis) < 0) {
         MESSAGE("ERROR : write of axis X coordinates ...");
         goto ERROR;
       }
      axis++;
      size = 3;
      if (MEDmeshGridIndexCoordinateWr(fid, meshname, MED_NO_DT, MED_NO_IT,0.0,
                                       axis, size, cooYaxis) < 0) {
        MESSAGE("ERROR : write of axis Y coordinates ...");
        goto ERROR;
      }

      /* optionnal : names for nodes or elements */
      /* In this case, a name is given to the cells of the mesh */
      if (MEDmeshEntityNameWr(fid, meshname, MED_NO_DT, MED_NO_IT,
                              MED_CELL, MED_QUAD4, nquad4,
                              cellsnames) < 0) {
        MESSAGE("ERROR : cells names  ...");
        goto ERROR;
      }

      /* create family 0 : by default, all mesh entities family number is 0 */
      if (MEDfamilyCr(fid, meshname,MED_NO_NAME, 0, 0, MED_NO_GROUP) < 0) {
        MESSAGE("ERROR : quadrangular cells connectivity ...");
        goto ERROR;
      }

      ret = 0;
     ERROR:

      /* close MED file  */
      if (MEDfileClose(fid) < 0) {
        MESSAGE("ERROR : close file ...");
        ret = -1;
      }

      return ret;
    }