topology/generateSimplicityTables2D.cpp

Creates precomputed tables for determining whether some point is simple within an 2D object.

Resulting table for 4-8 topology.

#include "DGtal/topology/tables/NeighborhoodTablesGenerators.h"
#include <vector>
#include "DGtal/shapes/Shapes.h"
#include "DGtal/io/boards/Board2D.h"
#include "DGtal/io/Color.h"
 
// For saving compressed tables.
#include <boost/iostreams/filtering_streambuf.hpp>
#include <boost/iostreams/copy.hpp>
#include <boost/iostreams/filter/zlib.hpp>
 
using namespace std;
using namespace DGtal;


template <typename Object, typename Map>
void
displaySimplicityTable( Board2D & board,
                        const typename Object::DigitalTopology & /*dt*/,
                        const Map & map )
{
  typedef typename Object::DigitalSet DigitalSet;
  typedef typename Object::Point Point;
  typedef typename DigitalSet::Domain Domain;
  typedef typename Domain::ConstIterator DomainConstIterator;
 
  Point p1 = Point::diagonal( -1 );
  Point p2 = Point::diagonal(  1 );
  Point c = Point::diagonal( 0 );
  Domain domain( p1, p2 );
 
  Point q1 = Point::diagonal( -1 );
  Point q2 = Point::diagonal( 4*16-1 );
  Domain fullDomain( q1, q2 );
  board << SetMode( fullDomain.className(), "Paving" );
  unsigned int cfg = 0;
  for ( unsigned int y = 0; y < 16; ++y )
    for ( unsigned int x = 0; x < 16; ++x, ++cfg )
      {
        bool simple = map[ cfg ];
        Point base( x*4, y*4 );
        unsigned int mask = 1;
        for ( DomainConstIterator it = domain.begin();
              it != domain.end(); ++it )
          {
            Point q = base + (*it);
            if ( *it == c )
              board << CustomStyle( q.className(),
                                    new CustomColors( Color( 0, 0, 0 ),
                                                      Color( 30, 30, 30 ) ) );
            else
              {
                if ( cfg & mask )
                  board <<
                    CustomStyle( q.className(),
                                 simple
                                 ? new CustomColors( Color( 0, 0, 0 ),
                                                     Color( 10, 255, 10 ) )
                                 : new CustomColors( Color( 0, 0, 0 ),
                                                     Color( 255, 10, 10 ) ) );
                else
                  board <<
                    CustomStyle( q.className(),
                                 simple
                                 ? new CustomColors( Color( 0, 0, 0 ),
                                                     Color( 245, 255, 245 ) )
                                 : new CustomColors( Color( 0, 0, 0 ),
                                                     Color( 255, 245, 245 ) ) );
                mask <<= 1;
              }
            board << q;
          }
      }
}

template <typename Map>
void
outputTableAsArray( ostream & out,
                    const Map & map,
                    const string & tableName )
{
  typedef typename Map::const_iterator MapConstIterator;
  out << "const bool " << tableName << "[ " << map.size() << " ] = { ";
  for ( MapConstIterator it = map.begin(), it_end = map.end();
        it != it_end; )
    {
      out << *it;
      ++it;
      if ( it != it_end ) out << ", ";
    }
  out << " };" << std::endl;
}
 
 
int main( int /*argc*/, char** /*argv*/ )
{
  typedef std::vector<bool> ConfigMap;
 
  using namespace Z2i;
  trace.beginBlock ( "Generate 2d table for 4-8 topology" );
  ConfigMap table4_8( 256 );
  functions::generateSimplicityTable< Object4_8 >( dt4_8, table4_8 );
  trace.endBlock();
 
  trace.beginBlock ( "Generate 2d table for 8-4 topology" );
  ConfigMap table8_4( 256 );
  functions::generateSimplicityTable< Object8_4 >( dt8_4, table8_4 );
  trace.endBlock();
 
  Board2D board;
  trace.beginBlock ( "Display 2d table for 4-8 topology" );
  displaySimplicityTable< Object4_8 >( board, dt4_8, table4_8 );
  board.saveEPS( "table4_8.eps" );
  trace.endBlock();
 
  board.clear();
  trace.beginBlock ( "Display 2d table for 8-4 topology" );
  displaySimplicityTable< Object8_4 >( board, dt8_4, table8_4 );
  board.saveEPS( "table8_4.eps" );
  trace.endBlock();
 
  outputTableAsArray( std::cout, table4_8, "simplicityTable4_8" );
  outputTableAsArray( std::cout, table8_4, "simplicityTable8_4" );
 
  /* Output bitset tables to files,
   * for using with NeighborhoodConfigurations.h interface.
   * These tables can be accesed from NeighborhoodTables.h header.
   */
  using ConfigMapBit = std::bitset<256> ; // 2^8
  ConfigMapBit bit_table8_4;
  ConfigMapBit bit_table4_8;
  functions::generateSimplicityTable< Object8_4 >( dt8_4, bit_table8_4 );
  functions::generateSimplicityTable< Object4_8 >( dt4_8, bit_table4_8 );
  // string filename = "simplicity_table8_4.txt";
  // ofstream file1( filename );
  // file1 << bit_table8_4;
  // file1.close();
  {
    string filename = "simplicity_table8_4.zlib";
    ofstream file( filename );
    ConfigMapBit* table = &bit_table8_4;
    std::stringstream table_stream;
    table_stream << *table;
    namespace io = boost::iostreams;
    io::filtering_streambuf<io::input> filter;
    filter.push(io::zlib_compressor());
    filter.push(table_stream);
    io::copy(filter,file);
    file.close();
  }
 
  // string filename = "simplicity_table4_8.txt";
  // ofstream file2( filename );
  // file2 << bit_table4_8;
  // file2.close();
  {
    string filename = "simplicity_table4_8.zlib";
    ofstream file( filename );
    ConfigMapBit* table = &bit_table4_8;
    std::stringstream table_stream;
    table_stream << *table;
    namespace io = boost::iostreams;
    io::filtering_streambuf<io::input> filter;
    filter.push(io::zlib_compressor());
    filter.push(table_stream);
    io::copy(filter,file);
    file.close();
  }
 
  return 0;
}
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