SpectralMeshTool.cpp

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#include "moab/SpectralMeshTool.hpp"
#include "moab/Interface.hpp"
#include "Internals.hpp"
#include "moab/ReadUtilIface.hpp"
#include "moab/CN.hpp"
 
#include <cmath>
#include <cassert>
 
namespace moab
{
const short int SpectralMeshTool::permute_array[] = { 0, 1, 13, 25, 3, 2, 14, 26, 7, 6, 18, 30, 11, 10, 22, 34 };
 
// lin_permute_array does the same to get the linear vertices of the coarse quad
const short int SpectralMeshTool::lin_permute_array[] = { 0, 25, 34, 11 };
 
Tag SpectralMeshTool::spectral_vertices_tag( const bool create_if_missing )
{
 ErrorCode rval = MB_SUCCESS;
 if( !svTag && create_if_missing )
 {
 if( !spectralOrder )
 {
 // should already be a spectral order tag...
 MB_SET_ERR_RET_VAL( "Spectral order must be set before creating spectral vertices tag", 0 );
 }
 
 // create it
 std::vector< EntityHandle > dum_val( spectralOrderp1 * spectralOrderp1, 0 );
 rval = mbImpl->tag_get_handle( "SPECTRAL_VERTICES", spectralOrderp1 * spectralOrderp1, MB_TYPE_HANDLE, svTag,
 MB_TAG_DENSE | MB_TAG_CREAT, &dum_val[0] );
 }
 
 return ( rval == MB_SUCCESS ? svTag : 0 );
}
 
/** \brief Return tag used to store spectral order
 * \param create_if_missing If true, will create this tag if it doesn't exist already
 */
Tag SpectralMeshTool::spectral_order_tag( const bool create_if_missing )
{
 ErrorCode rval = MB_SUCCESS;
 if( !soTag && create_if_missing )
 {
 
 // create it
 int dum = 0;
 rval = mbImpl->tag_get_handle( "SPECTRAL_ORDER", 1, MB_TYPE_INTEGER, soTag, MB_TAG_DENSE | MB_TAG_CREAT, &dum );
 }
 
 return ( rval == MB_SUCCESS ? soTag : 0 );
}
 
/** \brief Convert representation from coarse to fine
 * Each element in set, or in interface if set is not input, is converted to fine elements, using
 * vertices in SPECTRAL_VERTICES tagged array
 * \param spectral_set Set containing spectral elements
 */
ErrorCode SpectralMeshTool::convert_to_fine( EntityHandle /* spectral_set */ )
{
 return MB_NOT_IMPLEMENTED;
}
 
/** \brief Convert representation from fine to coarse
 * Each element in set, or in interface if set is not input, is converted to coarse elements, with
 * fine vertices put into SPECTRAL_VERTICES tagged array. NOTE: This function assumes that each
 * order^d (fine) elements comprise each coarse element, and are in order of fine elements in each
 * coarse element. If order is input as 0, looks for a SPECTRAL_ORDER tag on the mesh.
 * \param order Order of the spectral mesh
 * \param spectral_set Set containing spectral elements
 */
ErrorCode SpectralMeshTool::convert_to_coarse( int order, EntityHandle spectral_set )
{
 if( order ) spectralOrder = order;
 if( !spectralOrder )
 {
 MB_SET_ERR( MB_FAILURE, "Spectral order must be set or input before converting to spectral mesh" );
 }
 
 Range tmp_ents, ents;
 ErrorCode rval = mbImpl->get_entities_by_handle( spectral_set, tmp_ents );
 if( MB_SUCCESS != rval || ents.empty() ) return rval;
 
 // get the max-dimensional elements from it
 ents = tmp_ents.subset_by_dimension( 3 );
 if( ents.empty() ) ents = tmp_ents.subset_by_dimension( 2 );
 if( ents.empty() ) ents = tmp_ents.subset_by_dimension( 1 );
 if( ents.empty() )
 {
 MB_SET_ERR( MB_FAILURE, "Can't find any entities for conversion" );
 }
 
 // get a ptr to connectivity
 if( ents.psize() != 1 )
 {
 MB_SET_ERR( MB_FAILURE, "Entities must be in one chunk for conversion" );
 }
 EntityHandle* conn;
 int count, verts_per_e;
 rval = mbImpl->connect_iterate( ents.begin(), ents.end(), conn, verts_per_e, count );
 if( MB_SUCCESS != rval || count != (int)ents.size() ) return rval;
 
 Range tmp_range;
 return create_spectral_elems( conn, ents.size(), CN::Dimension( TYPE_FROM_HANDLE( *ents.begin() ) ), tmp_range );
}
 
template < class T >
ErrorCode SpectralMeshTool::create_spectral_elems( const T* conn,
 int num_fine_elems,
 int dim,
 Range& output_range,
 int start_idx,
 Range* local_gids )
{
 assert( spectralOrder && num_fine_elems );
 
 // now create num_coarse_elems
 // compute the number of local elems, accounting for coarse or fine representation
 // spectral_unit is the # fine elems per coarse elem, or spectralOrder^2
 int spectral_unit = spectralOrder * spectralOrder;
 int num_coarse_elems = num_fine_elems / spectral_unit;
 
 EntityHandle* new_conn;
 EntityHandle start_elem;
 ReadUtilIface* rmi;
 ErrorCode rval = mbImpl->query_interface( rmi );
 if( MB_SUCCESS != rval ) return rval;
 
 int verts_per_felem = spectralOrderp1 * spectralOrderp1, verts_per_celem = std::pow( (double)2.0, dim );
 
 rval = rmi->get_element_connect( num_coarse_elems, verts_per_celem, ( 2 == dim ? MBQUAD : MBHEX ), 0, start_elem,
 new_conn );MB_CHK_SET_ERR( rval, "Failed to create elems" );
 
 output_range.insert( start_elem, start_elem + num_coarse_elems - 1 );
 
 // read connectivity into that space
 
 // permute_array takes a 4*order^2-long vector of integers, representing the connectivity of
 // order^2 elems (fine elems in a coarse elem), and picks out the ids of the vertices necessary
 // to get a lexicographically-ordered array of vertices in a spectral element of that order
 // assert(verts_per_felem == (sizeof(permute_array)/sizeof(unsigned int)));
 
 // we're assuming here that elems was empty on input
 int count;
 EntityHandle* sv_ptr = NULL;
 rval = mbImpl->tag_iterate( spectral_vertices_tag( true ), output_range.begin(), output_range.end(), count,
 (void*&)sv_ptr );MB_CHK_SET_ERR( rval, "Failed to get SPECTRAL_VERTICES ptr" );
 assert( count == num_coarse_elems );
 int f = start_idx, fs = 0, fl = 0;
 for( int c = 0; c < num_coarse_elems; c++ )
 {
 for( int i = 0; i < verts_per_celem; i++ )
 new_conn[fl + i] = conn[f + lin_permute_array[i]];
 fl += verts_per_celem;
 for( int i = 0; i < verts_per_felem; i++ )
 sv_ptr[fs + i] = conn[f + permute_array[i]];
 f += verts_per_celem * spectral_unit;
 fs += verts_per_felem;
 }
 if( local_gids ) std::copy( sv_ptr, sv_ptr + verts_per_felem * num_coarse_elems, range_inserter( *local_gids ) );
 
 return MB_SUCCESS;
}
 
// force instantiation of a few specific types
template ErrorCode SpectralMeshTool::create_spectral_elems< int >( const int* conn,
 int num_fine_elems,
 int dim,
 Range& output_range,
 int start_idx,
 Range* local_gids );
template ErrorCode SpectralMeshTool::create_spectral_elems< EntityHandle >( const EntityHandle* conn,
 int num_fine_elems,
 int dim,
 Range& output_range,
 int start_idx,
 Range* local_gids );
} // namespace moab