TagIterateC.cpp

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    1 /*
    2  * This program shows how to get a pointer to tag memory, allowing an application to work
    3  * directly with tag memory instead of calling through the api.
    4  */
    5  
    6 #include "iMesh.h"
    7 #include "iMesh_extensions.h"
    8 #include <cstdio>
    9 #include <cstring>
   10  
   11 #define CHKERR( e, m )           \
   12     if( iBase_SUCCESS != ( e ) ) \
   13     {                            \
   14         printf( m );             \
   15         return 1;                \
   16     }
   17  
   18 int main( int argc, char* argv[] )
   19 {
   20     iMesh_Instance mesh;
   21     iBase_EntitySetHandle root_set;
   22     int err;
   23     const char* filename;
   24     iBase_EntityArrIterator iter;
   25     iBase_TagHandle tagh;
   26     int count, atend;
   27     double* tag_data;
   28     int num_regions;
   29  
   30     if( argc == 2 )
   31     {
   32         filename = argv[1];
   33     }
   34     else
   35     {
   36         printf( "Usage: %s <mesh_filename>\n", argv[0] );
   37         return 0;
   38     }
   39  
   40     /* initialize the Mesh */
   41     iMesh_newMesh( NULL, &mesh, &err, 0 );CHKERR( err, "Failed to create a mesh instance.\n" );
   42     iMesh_getRootSet( mesh, &root_set, &err );CHKERR( err, "Failed to return a root set.\n" );
   43  
   44     iMesh_load( mesh, root_set, filename, NULL, &err, strlen( filename ), 0 );
   45  
   46     /* get the number of regions in the mesh */
   47     iMesh_getNumOfType( mesh, root_set, iBase_REGION, &num_regions, &err );CHKERR( err, "Failed to get number of regions." );
   48  
   49     /* get an iterator to all regions in the model */
   50     iMesh_initEntArrIter( mesh, root_set, iBase_REGION, iMesh_ALL_TOPOLOGIES, num_regions, 0, &iter, &err );CHKERR( err, "Failed to create iterator over regions." );
   51  
   52     /* create a tag to put on the regions */
   53     iMesh_createTagWithOptions( mesh, "dumtag", "moab:TAG_STORAGE_TYPE=DENSE moab:TAG_DEFAULT_VALUE=0.0", 1,
   54                                 iBase_DOUBLE, &tagh, &err, 6, 54 );CHKERR( err, "Failed to create a tag.\n" );
   55  
   56     atend = 0;
   57  
   58     while( !atend )
   59     {
   60  
   61         /* get a pointer to that tag data; this will allocate tag storage if it isn't allocated yet
   62          */
   63         iMesh_tagIterate( mesh, tagh, iter, &tag_data, &count, &err );CHKERR( err, "Failed to create a tag.\n" );
   64  
   65         /* step the iterator over count entities */
   66         iMesh_stepEntArrIter( mesh, iter, count, &atend, &err );CHKERR( err, "Failed to step iterator.\n" );
   67  
   68         /* operate on tag data, or store it for later */
   69     }
   70  
   71     iMesh_dtor( mesh, &err );CHKERR( err, "Failed to destroy iMesh instance.\n" );
   72  
   73     return 0;
   74 }