FileRead.cpp

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    1 #include <iostream>
    2 #include <fstream>
    3 #include <vector>
    4 #include <string>
    5 #include <sstream>
    6  
    7 #include "moab/Core.hpp"
    8 #include "moab/ReadUtilIface.hpp"
    9  
   10 using namespace std;
   11 using namespace moab;
   12  
   13 int comment( string& line )
   14 {
   15     // if a line starts with '#' is a comment
   16     // eat white space characters
   17     size_t found = line.find_first_not_of( " \t" );
   18     if( found == string::npos ) return 1;  // empty line
   19     if( '#' == line[found] ) return 1;     // a comment indeed
   20     return 0;                              // a line with some data in it, then
   21 }
   22 ErrorCode ReadTriangleOutput( Interface* mb, string fileBase )
   23 {
   24  
   25     //
   26     // get the read interface from moab
   27     ReadUtilIface* iface;
   28     ErrorCode rval = mb->query_interface( iface );
   29     //
   30     if( MB_SUCCESS != rval )
   31     {
   32         cout << "Can't get interface.\n";
   33         return MB_FAILURE;
   34     }
   35     // Triangle default <name>.node
   36     string nodeFileName = fileBase + ".node";
   37     ifstream nodeFile( nodeFileName.c_str() );
   38     if( !nodeFile.is_open() )
   39     {
   40         cout << "can't open node file .\n";
   41         return MB_FILE_DOES_NOT_EXIST;
   42     }
   43     cout << "reading nodes from file " << nodeFileName.c_str() << endl;
   44  
   45     string eleFileName = fileBase + ".ele";
   46     ifstream eleFile( eleFileName.c_str() );
   47     if( !eleFile.is_open() )
   48     {
   49         cout << "can't open element file .\n";
   50         return MB_FILE_DOES_NOT_EXIST;
   51     }
   52     cout << "reading elements from file " << eleFileName.c_str() << endl;
   53  
   54     string line;
   55  
   56     // ignore comment lines that start with #
   57  
   58     int num_nodes = 0, num_triangles = 0;
   59     while( num_nodes == 0 )
   60     {
   61         getline( nodeFile, line );
   62         if( comment( line ) ) continue;
   63         stringstream tks( line );
   64         tks >> num_nodes;  // ignore the rest of the first line
   65                            // maybe will read attributes some other time
   66         cout << "num nodes:" << num_nodes << endl;
   67     }
   68  
   69     //  allocate a block of vertex handles and read xyz’s into them
   70     //  we know the size of the node arrays, and this call will allocate
   71     //   needed arrays, coordinate arrays
   72     //   also, it will return a starting handle for the node sequence
   73     vector< double* > arrays;
   74     EntityHandle startv;
   75     rval = iface->get_node_coords( 2, num_nodes, 0, startv, arrays );
   76     for( int i = 0; i < num_nodes; i++ )
   77     {
   78         getline( nodeFile, line );
   79         if( comment( line ) )
   80         {
   81             i--;  // read one more line
   82             continue;
   83         }
   84         stringstream tokens( line );
   85         int nodeId;
   86         tokens >> nodeId >> arrays[0][i] >> arrays[1][i];
   87     }
   88  
   89     // now read the element data from a different file
   90     // first, find out how many elements are out there
   91     // first line with data should have it
   92     while( num_triangles == 0 )
   93     {
   94         getline( eleFile, line );
   95         if( comment( line ) ) continue;
   96         stringstream tks( line );
   97         tks >> num_triangles;  // ignore the rest of the line
   98         cout << "num triangles:" << num_triangles << endl;
   99     }
  100  
  101     EntityHandle starte;
  102     EntityHandle* starth;  // the connectivity array that will get populated
  103                            // with triangle data
  104     // allocate block of triangle handles and read connectivity into them
  105     rval = iface->get_element_connect( num_triangles, 3, MBTRI, 0, starte, starth );
  106  
  107     for( int j = 0; j < num_triangles; j++ )
  108     {
  109         getline( eleFile, line );
  110         if( comment( line ) )
  111         {
  112             j--;  // read one more line
  113             continue;
  114         }
  115         stringstream tokens( line );
  116         int eleId;
  117         unsigned int node;
  118         tokens >> eleId;
  119         for( int k = 0; k < 3; k++ )
  120         {
  121             tokens >> node;
  122             // vertex handles start at startv
  123             starth[3 * j + k] = startv + node - 1;
  124         }
  125     }
  126  
  127     mb->release_interface( iface );
  128     //
  129     return MB_SUCCESS;
  130 }
  131  
  132 // .
  133 //  Read Triangle output files
  134 //  Assume that the format is <filename>.node and <filename>.ele
  135 //   see  http://www.cs.cmu.edu/~quake/triangle.html for details
  136 //
  137 int main( int argc, char** argv )
  138 {
  139     if( 3 != argc )
  140     {
  141         cout << "Usage: " << argv[0] << " <filename>  <outFile> " << endl;
  142         cout << "       <filename>  is the base file name; *.ele and *.node file are read; outFile "
  143                 "is a file with an extension recognized by MOAB "
  144              << endl;
  145         return 0;
  146     }
  147  
  148     string filename = argv[1];
  149     char* outfile   = argv[2];
  150  
  151     // get MOAB instance and read the file
  152     Core* mb = new Core();
  153  
  154     ErrorCode rval = ReadTriangleOutput( mb, filename );
  155  
  156     if( rval == MB_SUCCESS )
  157     {
  158         cout << "Writing output file " << outfile << endl;
  159         mb->write_file( outfile );
  160     }
  161  
  162     delete mb;
  163  
  164     return 0;
  165 }