msh_gmshreader.cc

Go to the documentation of this file.

/*!
 *
 * Copyright (C) 2007 Technical University of Liberec.  All rights reserved.
 *
 * Please make a following refer to Flow123d on your project site if you use the program for any purpose,
 * especially for academic research:
 * Flow123d, Research Centre: Advanced Remedial Technologies, Technical University of Liberec, Czech Republic
 *
 * This program is free software; you can redistribute it and/or modify it under the terms
 * of the GNU General Public License version 3 as published by the Free Software Foundation.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not,
 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 021110-1307, USA.
 *
 *
 * $Id$
 * $Revision$
 * $LastChangedBy$
 * $LastChangedDate$
 *
 * @file
 * @ingroup mesh
 * @brief
 * @author dalibor
 * 
 * @date Created on October 3, 2010, 11:32 AM
 */

#include <istream>
#include <string>
#include <limits>

#include "msh_gmshreader.h"

#include "system/system.hh"
#include "system/sys_profiler.hh"
#include "system/tokenizer.hh"
#include "boost/lexical_cast.hpp"

#include "mesh/mesh.h"
#include "mesh/nodes.hh"


using namespace std;


GmshMeshReader::GmshMeshReader(const FilePath &file_name)
: tok_(file_name)
{
    tok_.set_comment_pattern( "#");
    last_header.time=-numeric_limits<double>::infinity();
    last_header.actual=false;
}



GmshMeshReader::GmshMeshReader(std::istream &in)
: tok_(in)
{
    tok_.set_comment_pattern( "#");
    last_header.time=-numeric_limits<double>::infinity();
    last_header.actual=false;
}



GmshMeshReader::~GmshMeshReader()   // Tokenizer close the file automatically
{}



void GmshMeshReader::read_mesh(Mesh* mesh, const RegionDB::MapElementIDToRegionID *el_to_reg_map) {
    START_TIMER("GMSHReader - read mesh");
    
    ASSERT( mesh , "Argument mesh is NULL.\n");
    read_physical_names(tok_, mesh);
    read_nodes(tok_, mesh);
    read_elements(tok_, mesh, el_to_reg_map);
}



void GmshMeshReader::read_nodes(Tokenizer &tok, Mesh* mesh) {
    using namespace boost;
    xprintf(Msg, "- Reading nodes...");

    if (! tok.skip_to("$Nodes")) xprintf(UsrErr,"Missing section '$Nodes' in the GMSH input file: %s\n",tok.f_name().c_str());
    try {
        tok.next_line(false);
        unsigned int n_nodes = lexical_cast<unsigned int> (*tok);;
        INPUT_CHECK( n_nodes > 0, "Zero number of nodes, %s.\n", tok.position_msg().c_str() );
        ++tok; // end of line

        mesh->node_vector.reserve(n_nodes);
        for (unsigned int i = 0; i < n_nodes; ++i) {
            tok.next_line();

            unsigned int id = lexical_cast<unsigned int> (*tok); ++tok;
            NodeFullIter node = mesh->node_vector.add_item(id);

            node->point()(0)=lexical_cast<double> (*tok); ++tok;
            node->point()(1)=lexical_cast<double> (*tok); ++tok;
            node->point()(2)=lexical_cast<double> (*tok); ++tok;
            ++tok; // skip mesh size parameter
        }

    } catch (bad_lexical_cast &) {
        xprintf(UsrErr, "Wrong format of number, %s.\n", tok.position_msg().c_str());
    }
    xprintf(Msg, " %d nodes read. \n", mesh->node_vector.size());
}



void GmshMeshReader::read_elements(Tokenizer &tok, Mesh * mesh, const RegionDB::MapElementIDToRegionID *el_to_reg_map) {
    using namespace boost;
    xprintf(Msg, "- Reading elements...");

    if (! tok.skip_to("$Elements")) xprintf(UsrErr,"Missing section '$Elements' in the GMSH input file: %s\n",tok.f_name().c_str());
    try {
        tok.next_line(false);
        unsigned int n_elements = lexical_cast<unsigned int> (*tok);
        INPUT_CHECK( n_elements > 0, "Zero number of elements, %s.\n", tok.position_msg().c_str());
        ++tok; // end of line

        mesh->element.reserve(n_elements);

        for (unsigned int i = 0; i < n_elements; ++i) {
            tok.next_line();

            unsigned int id = lexical_cast<unsigned int>(*tok); ++tok;


            //get element type: supported:
            //  1 Line (2 nodes)
            //  2 Triangle (3 nodes)
            //  4 Tetrahedron (4 nodes)
            // 15 Point (1 node)
            unsigned int type = lexical_cast<unsigned int>(*tok); ++tok;
            unsigned int dim;
            switch (type) {
                case 1:
                    dim = 1;
                    break;
                case 2:
                    dim = 2;
                    break;
                case 4:
                    dim = 3;
                    break;
                case 15:
                    dim = 0;
                    break;
                default:
                    dim = 0;
                    xprintf(UsrErr, "Element %d is of the unsupported type %d\n", id, type);
                    break;
            }

            //get number of tags (at least 2)
            unsigned int n_tags = lexical_cast<unsigned int>(*tok);
            INPUT_CHECK(n_tags >= 2, "At least two element tags have to be defined for element with id=%d, %s.\n",
                    id, tok.position_msg().c_str());
            ++tok;

            //get tags 1 and 2
            unsigned int region_id = lexical_cast<unsigned int>(*tok); ++tok;
            lexical_cast<unsigned int>(*tok); ++tok; // GMSH region number, we do not store this
            //get remaining tags
            unsigned int partition_id=0;
            if (n_tags > 2)  { partition_id = lexical_cast<unsigned int>(*tok); ++tok; } // save partition number from the new GMSH format
            for (unsigned int ti = 3; ti < n_tags; ti++) ++tok;         //skip remaining tags

            // allocate element arrays TODO: should be in mesh class
            Element *ele=nullptr;
            // possibly modify region id
            if (el_to_reg_map) {
                RegionDB::MapElementIDToRegionID::const_iterator it = el_to_reg_map->find(id);
                if (it != el_to_reg_map->end()) region_id = it->second;
            }
            RegionIdx region_idx = mesh->region_db_.add_region( region_id, dim );

            if (region_idx.is_boundary()) {
                ele = mesh->bc_elements.add_item(id);
            } else {
                if(dim == 0 )
                    xprintf(Warn, "Bulk elements of zero size(dim=0) are not supported. Mesh file: %s, Element ID: %d.\n", tok.f_name().c_str() ,id);
                else
                    ele = mesh->element.add_item(id);
            }
            ele->init(dim, mesh, region_idx);
            ele->pid=partition_id;

            unsigned int ni;
            FOR_ELEMENT_NODES(ele, ni) {
                unsigned int node_id = lexical_cast<unsigned int>(*tok);
                NodeIter node = mesh->node_vector.find_id( node_id );
                INPUT_CHECK( node!=mesh->node_vector.end() ,
                        "Unknown node id %d in specification of element with id=%d, %s.\n",
                        node_id, id, tok.position_msg().c_str());
                ele->node[ni] = node;
                ++tok;
            }
        }

    } catch (bad_lexical_cast &) {
        xprintf(UsrErr, "Wrong format of number, %s.\n", tok.position_msg().c_str());
    }

    mesh->n_all_input_elements_=mesh->element.size() + mesh->bc_elements.size();
    xprintf(Msg, " %d bulk elements, %d boundary elements. \n", mesh->element.size(), mesh->bc_elements.size());
}



void GmshMeshReader::read_physical_names(Tokenizer &tok, Mesh * mesh) {
    using namespace boost;

    if (! tok.skip_to("$PhysicalNames", "$Nodes") ) return;
    try {
        tok.next_line(false);
        unsigned int n_physicals = lexical_cast<unsigned int> (*tok);
        ++tok; // end of line

        for (unsigned int i = 0; i < n_physicals; ++i) {
            tok.next_line();
            // format of one line:
            // dim    physical-id    physical-name

            unsigned int dim = lexical_cast<unsigned int>(*tok); ++tok;
            unsigned int id = lexical_cast<unsigned int>(*tok); ++tok;
            string name = *tok; ++tok;

            mesh->region_db_.add_region(id, name, dim);
        }

    } catch (bad_lexical_cast &) {
        xprintf(UsrErr, "Wrong format of number, %s.\n", tok.position_msg().c_str());
    }
}


// Is assumed to be called just after tok.skip_to("..")
// reads the header from the tokenizer @p tok and return it as the second parameter
void GmshMeshReader::read_data_header(Tokenizer &tok, GMSH_DataHeader &head) {
    using namespace boost;
    try {
        // string tags
        tok.next_line(false);
        unsigned int n_str = lexical_cast<unsigned int>(*tok); ++tok;
        head.field_name="";
        head.interpolation_scheme = "";
        if (n_str > 0) {
            tok.next_line(); n_str--;
            head.field_name= *tok; ++tok; //  unquoted by tokenizer if needed
        }
        if (n_str > 0) {
            tok.next_line(); n_str--;
            head.interpolation_scheme = *tok; ++tok;
        }
        for(;n_str>0;n_str--) tok.next_line(false); // skip possible remaining tags

        //real tags
        tok.next_line();
        unsigned int n_real = lexical_cast<unsigned int>(*tok); ++tok;
        head.time=0.0;
        if (n_real>0) {
            tok.next_line(); n_real--;
            head.time=lexical_cast<double>(*tok); ++tok;
        }
        for(;n_real>0;n_real--) tok.next_line(false);

        // int tags
        tok.next_line();
        unsigned int n_int = lexical_cast<unsigned int>(*tok); ++tok;
        head.time_index=0;
        head.n_components=1;
        head.n_entities=0;
        head.partition_index=0;
        if (n_int>0) {
            tok.next_line(); n_int--;
            head.time_index=lexical_cast<unsigned int>(*tok); ++tok;
        }
        if (n_int>0) {
            tok.next_line(); n_int--;
            head.n_components=lexical_cast<unsigned int>(*tok); ++tok;
        }
        if (n_int>0) {
            tok.next_line(); n_int--;
            head.n_entities=lexical_cast<unsigned int>(*tok); ++tok;
        }
        for(;n_int>0;n_int--) tok.next_line(false);
    } catch (bad_lexical_cast &) {
                xprintf(UsrErr, "Wrong format of the $ElementData header, %s.\n", tok.position_msg().c_str());
    }
}



void GmshMeshReader::read_element_data( GMSH_DataHeader &search_header,
        double *data, std::vector<int> const & el_ids)
{

    using namespace boost;

    unsigned int id, idx, n_read;
    vector<int>::const_iterator id_iter;
    double * data_ptr;

    while ( last_header.time <= search_header.time*(1.0 + 2.0*numeric_limits<double>::epsilon()) ) {
        // @p data buffer is not actual anymore

        if (last_header.actual) {
            // read @p data buffer as we have correct header with already passed time
            // we assume that @p data buffer is big enough

            n_read = 0;
            id_iter=el_ids.begin();
            unsigned int i_row;
            for (i_row = 0; i_row < last_header.n_entities; ++i_row)
                try {
                    tok_.next_line();
                    id = lexical_cast<unsigned int>(*tok_); ++tok_;
                    while (id_iter != el_ids.end() && *id_iter < (int)id) {
                        ++id_iter; // skip initialization of some rows in data if ID is missing
                    }
                    if (id_iter == el_ids.end()) {
                        xprintf(Warn,"In file '%s', '$ElementData' section for field '%s', time: %f.\nData ID %d not found or is not in order. Skipping rest of data.\n",
                                tok_.f_name().c_str(), search_header.field_name.c_str(), last_header.time, id);
                        break;
                    }
                    // save data from the line if ID was found
                    if (*id_iter == (int)id) {
                        idx = id_iter - el_ids.begin();
                        data_ptr = data + idx * search_header.n_components;
                        for (unsigned int i_col =0; i_col < search_header.n_components; ++i_col, ++data_ptr) {
                            *(data_ptr) = lexical_cast<double>(*tok_); ++tok_;
                        }
                        n_read++;
                    }
                    // skip the line if ID on the line  < actual ID in the map el_ids
                } catch (bad_lexical_cast &) {
                    xprintf(UsrErr, "Wrong format of $ElementData line, %s.\n", tok_.position_msg().c_str());
                }
            // possibly skip remaining lines after break
            while (i_row < last_header.n_entities) tok_.next_line(false), ++i_row;

            xprintf(Msg, "time: %f; %d entities of field %s read.\n",
                    last_header.time, n_read, last_header.field_name.c_str());

            search_header.actual = true; // use input header to indicate modification of @p data buffer
        }

        // find next the data section of corresponding field name
        last_header.field_name="";
        while (! tok_.eof() && last_header.field_name != search_header.field_name) {
            if ( tok_.skip_to("$ElementData") )
                read_data_header(tok_, last_header);
        }

        if (tok_.eof()) {
            if (! last_header.actual) {
                // first call of the method, no data read
                xprintf(UsrErr, "In file '%s', missing '$ElementData' section for field '%s'.\n",
                        tok_.f_name().c_str(), search_header.field_name.c_str());
                return;
            } else {
                // mark data as actual until inf
                last_header.time=numeric_limits<double>::infinity(); //
                return;
            }
        } else {
            // check that the header is valid, try to correct
            if (last_header.n_components != search_header.n_components) {
                xprintf(Warn, "In file '%s', '$ElementData' section for field '%s', time: %f.\nWrong number of components: %d, using %d instead.\n",
                        tok_.f_name().c_str(), search_header.field_name.c_str(), last_header.time, last_header.n_components, search_header.n_components);
                last_header.n_components=search_header.n_components;
            }
            if (last_header.n_entities != search_header.n_entities) {
                xprintf(Warn, "In file '%s', '$ElementData' section for field '%s', time: %f.\nWrong number of entities: %d, using %d instead.\n",
                        tok_.f_name().c_str(), search_header.field_name.c_str(), last_header.time, last_header.n_entities, search_header.n_entities);
                // last_header.n_entities=search_header.n_entities;
            }

        }
        last_header.actual=true;

    } // time loop
}