# usecases/c/UsesCase_MEDmesh_12.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/>.
     */

    /*
     *  Use case 12 : read a 2D unstructured mesh with moving grid (generic approach)
     */

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

    #include <string.h>

    int main (int argc, char **argv) {
      med_idt fid;
      med_int nmesh;
      char meshname[MED_NAME_SIZE+1]="";
      char meshdescription[MED_COMMENT_SIZE+1]="";
      med_int meshdim;
      med_int spacedim;
      med_sorting_type sortingtype;
      med_int nstep;
      med_mesh_type meshtype;
      med_axis_type axistype;
      char *axisname;
      char *unitname;
      char dtunit[MED_SNAME_SIZE+1]="";
      med_float *coordinates = NULL;
      med_int ngeo = 0;
      med_int nnodes = 0;
      med_int *connectivity = NULL;
      med_bool coordinatechangement;
      med_bool geotransformation;
      med_bool matrixtransformation;
      med_int matrixsize;
      med_float matrix[7]={ 0, 0, 0, 0, 0, 0, 0};
      int i, it, j;
      med_int profilesize;
      char profilename[MED_NAME_SIZE+1]="";
      med_int numdt, numit;
      med_float dt;
      med_geometry_type geotype;
      med_geometry_type *geotypes = MED_GET_CELL_GEOMETRY_TYPE;
      int ret=-1;

      /* open MED file with READ ONLY access mode */
      fid = MEDfileOpen("UsesCase_MEDmesh_9.med",MED_ACC_RDONLY);
      if (fid < 0) {
        MESSAGE("ERROR : open file in READ ONLY ACCESS mode ...");
        goto ERROR;
      }

      /* read how many mesh in the file */
      if ((nmesh = MEDnMesh(fid)) < 0) {
        MESSAGE("ERROR : read how many mesh ...");
        goto ERROR;
      }

      for (i=0;i<nmesh;i++) {

        /* read computation space dimension */
        if ((spacedim = MEDmeshnAxis(fid, i+1)) < 0) {
          MESSAGE("ERROR : read computation space dimension ...");
          goto ERROR;
        }

        /* memory allocation */
        if ((axisname  = (char*) malloc(MED_SNAME_SIZE*spacedim+1)) == NULL) {
          MESSAGE("ERROR : memory allocation ...");
          goto ERROR;
        }
        if ((unitname  = (char*) malloc(MED_SNAME_SIZE*spacedim+1)) == NULL) {
          MESSAGE("ERROR : memory allocation ...");
          goto ERROR;
        }

        /* read mesh informations : meshname, mesh dimension, mesh type ... */
        if (MEDmeshInfo(fid, i+1, meshname, &spacedim, &meshdim, &meshtype, meshdescription,
                        dtunit, &sortingtype, &nstep,
                        &axistype, axisname, unitname) < 0) {
          MESSAGE("ERROR : mesh info ...");
          free(axisname);
          free(unitname);
          goto ERROR;
        }
        free(axisname);
        free(unitname);

        /* read how many nodes in the mesh */
        if ((nnodes = MEDmeshnEntity(fid, meshname, MED_NO_DT, MED_NO_IT, MED_NODE, MED_NONE,
                                     MED_COORDINATE, MED_NO_CMODE,&coordinatechangement,
                                     &geotransformation)) < 0) {
          MESSAGE("ERROR : number of nodes ...");
          goto ERROR;
        }

        /* read mesh nodes coordinates */
        if ((coordinates = (med_float*) malloc(sizeof(med_float)*nnodes*spacedim)) == NULL) {
          MESSAGE("ERROR : memory allocation ...");
          goto ERROR;
        }

        if (MEDmeshNodeCoordinateRd(fid, meshname, MED_NO_DT, MED_NO_IT, MED_FULL_INTERLACE,
                                    coordinates) < 0) {
          MESSAGE("ERROR : nodes coordinates ...");
          free(coordinates);
          goto ERROR;
        }

        /* read all MED geometry cell types */
        for (it=1; it<= MED_N_CELL_FIXED_GEO; it++) {

          geotype = geotypes[it];

          if ((ngeo = MEDmeshnEntity(fid, meshname, MED_NO_DT, MED_NO_IT, MED_CELL,geotype,
                                     MED_CONNECTIVITY, MED_NODAL, &coordinatechangement,
                                     &geotransformation)) < 0) {
            MESSAGE("ERROR : number of cell ...");
            ISCRUTE(geotype);
            goto ERROR;
          }

          if (ngeo) {
            /* read cells connectivity in the mesh */
            if ((connectivity = (med_int *) malloc(sizeof(med_int)*ngeo*(geotype%100))) == NULL) {
              MESSAGE("ERROR : memory allocation ...");
              goto ERROR;
            }

            if (MEDmeshElementConnectivityRd(fid, meshname, MED_NO_DT, MED_NO_IT, MED_CELL,
                                             geotype, MED_NODAL, MED_FULL_INTERLACE, connectivity) < 0) {
              MESSAGE("ERROR : cellconnectivity ...");
              ISCRUTE(geotype);
              free(connectivity);
              goto ERROR;
            }

            /* memory deallocation */
            free(connectivity);
            connectivity = NULL;
          }
        }

        /* read nodes coordinates changements step by step */
        for (it=1;it<nstep;it++) {

          if (MEDmeshComputationStepInfo(fid, meshname, it+1,
                                         &numdt, &numit, &dt) < 0) {
            MESSAGE("ERROR : Computing step info ...");
            SSCRUTE(meshname);
            goto ERROR;
          }

          /* test changement : for nodes coordinates */
          if ((nnodes = MEDmeshnEntityWithProfile(fid, meshname, numdt, numit,
                                                  MED_NODE, MED_NONE,
                                                  MED_COORDINATE, MED_NO_CMODE,
                                                  MED_GLOBAL_PFLMODE, profilename, &profilesize,
                                                  &coordinatechangement, &geotransformation)) < 0) {
            MESSAGE("ERROR : number of nodes ...");
            goto ERROR;
          }

          /* if only coordinates have changed, then read the new coordinates */
          if (coordinatechangement && geotransformation) {
            if (MEDmeshNodeCoordinateWithProfileRd(fid, meshname, numdt, numit,
                                                   MED_GLOBAL_PFLMODE,profilename,
                                                   MED_FULL_INTERLACE,MED_ALL_CONSTITUENT,
                                                   coordinates) < 0) {
              MESSAGE("ERROR : nodes coordinates ...");
              free(coordinates);
              goto ERROR;
            }
          }

          if (coordinatechangement && ! geotransformation) {

            matrixsize = MEDmeshnEntity(fid,meshname,numdt,numit,
                                        MED_NODE,MED_NONE,MED_COORDINATE_TRSF,MED_NODAL,&coordinatechangement,
                                        &matrixtransformation);

            if (matrixsize < 0) {
              MESSAGE("ERROR : matrix transformation ...");
              goto ERROR;
            }

            if (matrixtransformation) {
              if ( MEDmeshNodeCoordinateTrsfRd(fid, meshname, numdt, numit, matrix) < 0 ) {
                MESSAGE("ERROR : read transformation matrix ...");
                goto ERROR;
              }
            }
          }
        }
      }
      free(coordinates);

      ret=0;
     ERROR:

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

      return ret;
    }