# usecases/c/UsesCase_MEDfield_18.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/>.
     */

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

    #include <string.h>

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

    #include <string.h>

    /*
     * Field use case 18 : read a field (generic approach) in a MED file with
     *                     values defined on integration points on struct elements
     */

    int main (int argc, char **argv) {
      med_idt fid,mfid,sfid,cmfid;
      med_idt nfield, i, j;
      char meshname[MED_NAME_SIZE+1]="";
      med_bool localmesh;
      char fieldname[MED_NAME_SIZE+1]="";
      med_field_type fieldtype;
      char *componentname = NULL;
      char *componentunit = NULL;
      char dtunit[MED_SNAME_SIZE+1]="";
      med_float *values = NULL;
      med_int nstep, nvalues;
      med_int ncomponent;
      med_int csit, numit, numdt, it;
      med_float dt;
      med_geometry_type *geotypes=NULL, geotype;
      med_int nmodels;
      med_int nprofile, pit, profilesize;
      char profilename[MED_NAME_SIZE+1]="";
      med_int nintegrationpoint;
      char localizationname[MED_NAME_SIZE+1]="";
      int k;
      char elementname[MED_NAME_SIZE+1]="";
      char supportmeshname[MED_NAME_SIZE+1]="";
      med_entity_type entitype;
      med_int elementdim;
      med_int nnode,ncell;
      med_geometry_type geocelltype;
      med_bool anyprofile=0;
      med_int nconstatt, *nvaratt=NULL;
      med_bool coordinatechangement;
      med_bool geotransformation;
      int ret=-1;

      /* open file */
      fid = MEDfileOpen("UsesCase_MEDfield_17.med",MED_ACC_RDWR);
      if (fid < 0) {
        MESSAGE("ERROR : open file ...");
        return -1;
      }

      if (( mfid=MEDfileObjectsMount(fid,  "UsesCase_MEDstructElement_1.med",MED_MESH_SUPPORT)) < 0 ) {
        MESSAGE("ERROR : file mounting ...");
        return -1;
      }

      if (( sfid=MEDfileObjectsMount(fid,  "UsesCase_MEDstructElement_1.med",MED_ELSTRUCT)) < 0 ) {
        MESSAGE("ERROR : file mounting ...");
        return -1;
      }

      if (( cmfid=MEDfileObjectsMount(fid,  "UsesCase_MEDstructElement_1.med",MED_MESH)) < 0 ) {
        MESSAGE("ERROR : file mounting ...");
        return -1;
      }

      /*
       * generic approach : how many fields in the file and identification
       * of each field.
       */
      if ((nfield = MEDnField(fid)) < 0) {
        MESSAGE("ERROR : How many fields in the file ...");
        return -1;
      }

      /*
       * read values for each field
       */
      for (i=0; i<nfield; i++) {

        if ((ncomponent = MEDfieldnComponent(fid,i+1)) < 0) {
          MESSAGE("ERROR : number of field component ...");
          return -1;
        }

        if ((componentname = (char *) malloc(ncomponent*MED_SNAME_SIZE+1)) == NULL) {
          MESSAGE("ERROR : memory allocation ...");
          return -1;
        }

        if ((componentunit = (char *) malloc(ncomponent*MED_SNAME_SIZE+1)) == NULL) {
          MESSAGE("ERROR : memory allocation ...");
          return -1;
        }

        if (MEDfieldInfo(fid, i+1, fieldname, meshname, &localmesh, &fieldtype,
                         componentname, componentunit, dtunit, &nstep) < 0) {
          MESSAGE("ERROR : Field info ...");
          free(componentname);
          free(componentunit);
          return -1;
        }

        free(componentname);
        free(componentunit);

        /* read how many struct element models in the mesh ? */
        if ((nmodels = MEDmeshnEntity(fid, meshname, MED_NO_DT, MED_NO_IT, MED_STRUCT_ELEMENT, MED_GEO_ALL,
                                      MED_UNDEF_DATATYPE, MED_NO_CMODE,&coordinatechangement,
                                      &geotransformation)) < 0) {
          MESSAGE("ERROR : number of nodes ...");
          return -1;
        }
        geotypes = (med_geometry_type *) malloc(sizeof(med_geometry_type)*nmodels);
        nvaratt = (med_int *) malloc(sizeof(med_int)*nmodels);

        for (it=0; it<nmodels; it++) {
          if (MEDstructElementInfo(mfid, it+1, elementname, geotypes+it, &elementdim,
                                   supportmeshname, &entitype, &nnode, &ncell,
                                   &geocelltype, &nconstatt, &anyprofile, nvaratt+it) < 0) {
            MESSAGE("ERROR : struct element models information ...");
            return -1;
          }
        }

        /*
         * Read field values for each computing step
         */
        for (csit=0; csit<nstep; csit++) {

          if (MEDfieldComputingStepInfo(fid, fieldname, csit+1, &numdt, &numit, &dt) < 0) {
            MESSAGE("ERROR : Computing step info ...");
            return -1;
          }

          /*
           * ... In our case, we suppose that the field values are only defined on struct element ...
           */
          for (it=0; it<nmodels; it++) {
            geotype = *(geotypes+it);

            /*
             * How many profile for each geometry type ?
             */
            if ((nprofile = MEDfieldnProfile(fid, fieldname, numdt, numit, MED_STRUCT_ELEMENT, geotype,
                                             profilename, localizationname)) < 0) {
              MESSAGE("ERROR : read number of profile ");
              return -1;
            }

            /*
             * Read values for each profile
             */
            for (pit=0; pit<nprofile; pit++) {

              if ((nvalues = MEDfieldnValueWithProfile(fid, fieldname, numdt, numit, MED_STRUCT_ELEMENT, geotype,
                                                       pit+1, MED_COMPACT_PFLMODE, profilename, &profilesize,
                                                       localizationname, &nintegrationpoint)) < 0) {
                MESSAGE("ERROR : read number of values with a profile ...");
                return -1;
              }

              if (nvalues) {
                if ((values = (med_float *) malloc(sizeof(med_float)*nvalues*ncomponent*nintegrationpoint)) == NULL) {
                  MESSAGE("ERROR : memory allocation ...");
                  return -1;
                }
                if (MEDfieldValueWithProfileRd(fid, fieldname, numdt, numit, MED_STRUCT_ELEMENT, geotype,
                                               MED_COMPACT_PFLMODE, profilename,
                                               MED_FULL_INTERLACE, MED_ALL_CONSTITUENT,
                                               (unsigned char*) values) < 0) {
                  MESSAGE("ERROR : read fields values for cells ...");
                  free(values);
                  return -1;
                }
                free(values);
              }
            }
          }
        }

        ret=0;
      ERROR:
        if (nvaratt)
          free(nvaratt);
        if (geotypes)
          free(geotypes);

      }

      if ( MEDfileObjectsUnmount(fid, mfid, MED_MESH_SUPPORT) < 0 ) {
        MESSAGE("ERROR : file unmounting ...");
        ret=-1;
      }

      if ( MEDfileObjectsUnmount(fid, sfid, MED_ELSTRUCT) < 0 ) {
        MESSAGE("ERROR : file unmounting ...");
        ret=-1;
      }

      if ( MEDfileObjectsUnmount(fid, cmfid, MED_MESH) < 0 ) {
        MESSAGE("ERROR : file unmounting ...");
        ret=-1;
      }

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

      return ret;
    }