Boolean_set_operations_2/bezier_traits_adapter2.cpp

#include <CGAL/config.h>

#ifndef CGAL_USE_CORE
#include <iostream>
int main()
{
  std::cout << "Sorry, this example needs CORE ..." << std::endl;
  return (0);
}
#else

#include <CGAL/Cartesian.h>
#include <CGAL/CORE_algebraic_number_traits.h>
#include <CGAL/Arr_Bezier_curve_traits_2.h>
#include <CGAL/Gps_traits_2.h>
#include <CGAL/Boolean_set_operations_2.h>
#include <CGAL/General_polygon_set_2.h>
#include <CGAL/Timer.h>

#include <fstream>

typedef CGAL::CORE_algebraic_number_traits            Nt_traits;
typedef Nt_traits::Rational                           Rational;
typedef Nt_traits::Algebraic                          Algebraic;

typedef CGAL::Cartesian<Rational>                     Rat_kernel;
typedef CGAL::Cartesian<Algebraic>                    Alg_kernel;
typedef CGAL::Arr_Bezier_curve_traits_2<Rat_kernel, Alg_kernel, Nt_traits>
                                                      Traits_2;

typedef Rat_kernel::Point_2                           Bezier_rat_point;
typedef Traits_2::Curve_2                             Bezier_curve;
typedef Traits_2::X_monotone_curve_2                  Bezier_X_monotone_curve;
typedef CGAL::Gps_traits_2<Traits_2>                  Bezier_traits;
typedef Bezier_traits::General_polygon_2              Bezier_polygon;
typedef Bezier_traits::General_polygon_with_holes_2   Bezier_polygon_with_holes;
typedef CGAL::General_polygon_set_2<Bezier_traits>    Bezier_polygon_set;
typedef std::vector<Bezier_polygon>                   Bezier_polygon_vector;

Bezier_curve read_bezier_curve(std::istream& is, bool aDoubleFormat)
{
  // Read the number of control points.
  unsigned int  n;

  is >> n;

  // Read the control points.
  std::vector<Bezier_rat_point> ctrl_pts;
  for (unsigned int k = 0; k < n; ++k) {
    Bezier_rat_point p;
    if (aDoubleFormat) {
      double x, y;
      is >> x >> y;
      p = Bezier_rat_point(x,y);
    }
    else
      is >> p;

    if ((k == 0) || (ctrl_pts[k-1] != p))
      ctrl_pts.push_back(p);
  }

  return Bezier_curve(ctrl_pts.begin(), ctrl_pts.end());
}

bool read_bezier(char const* aFileName, Bezier_polygon_set& rSet)
{

  bool rOK = false;

  std::ifstream in_file(aFileName);

  if (in_file) {
    try {
      std::cout << "Reading " << aFileName << std::endl;

      std::string format;
      std::getline(in_file, format);

      bool lDoubleFormat =
        ((format.length() >= 6) && (format.substr(0,6) == "DOUBLE"));

      // Red the number of bezier polygon with holes
      unsigned int n_regions;
      in_file >> n_regions;

      for (unsigned int r = 0; r < n_regions; ++r) {
        Bezier_polygon_vector  polygons;

        // Read the number of bezier curves.
        unsigned int n_boundaries;
        in_file >> n_boundaries;

        for (unsigned int b = 0; b < n_boundaries; ++b) {
          // Read the number of bezier curves.
          unsigned int n_curves;
          in_file >> n_curves;

          // Read the curves one by one, and construct the general polygon these
          // curve form (the outer boundary and the holes inside it).

          std::list<Bezier_X_monotone_curve> xcvs;

          for (unsigned int k = 0; k < n_curves; ++k) {
            // Read the current curve and subdivide it into x-monotone subcurves.

            std::list<CGAL::Object>                 x_objs;
            std::list<CGAL::Object>::const_iterator xoit;
            Bezier_X_monotone_curve                 xcv;
            Bezier_traits                           traits;
            Bezier_traits::Make_x_monotone_2        make_x_monotone =
              traits.make_x_monotone_2_object();

            Bezier_curve B = read_bezier_curve(in_file, lDoubleFormat);
            if (B.number_of_control_points() >= 2) {

              make_x_monotone(B, std::back_inserter(x_objs));

              for (xoit = x_objs.begin(); xoit != x_objs.end(); ++xoit) {
                if (CGAL::assign(xcv, *xoit))
                  xcvs.push_back(xcv);
              }
            }
          }

          Bezier_polygon  pgn(xcvs.begin(), xcvs.end());

          CGAL::Orientation  orient = pgn.orientation();
          std::cout << "  Orientation: " << orient << std::endl;

          if (((b == 0) && (orient == CGAL::CLOCKWISE)) ||
              ((b > 0) && (orient == CGAL::COUNTERCLOCKWISE)))
          {
            std::cout << "    Reversing orientation: " << std::endl;
            pgn.reverse_orientation();
          }

          polygons.push_back(pgn);
        }

        if (polygons.size() > 0) {
          Bezier_polygon_with_holes pwh(polygons.front());

          if (polygons.size() > 1) {
            Bezier_polygon_vector::const_iterator it;
            for (it = CGAL::cpp11::next(polygons.begin());
                 it != polygons.end(); ++it)
              pwh.add_hole(*it);
          }

          if (is_valid_polygon_with_holes(pwh, rSet.traits())) {
            std::cout << "  Inserting Bezier polygon with holes comprising "
                      << polygons.size() << " boundaries in total into set."
                      << std::endl;
            rSet.join(pwh);
            std::cout << "    Done." << std::endl;
          }
          else
            std::cout << "  **** Bezier polygon with holes is NOT VALID ****"
                      << std::endl;
        }

        rOK = true;
      }
    }
    catch(std::exception const& x) {
      std::cout << "An exception ocurred during reading of Bezier polygon set:"
                << x.what() << std::endl;
    }
    catch(...) {
      std::cout << "An exception ocurred during reading of Bezier polygon set."
                << std::endl;
    }
  }

  return rOK;
}

// The main program.
int main(int argc, char* argv[])
{
  const char* filename1 = (argc > 1) ? argv[1] : "char_g.bps";
  const char* filename2 = (argc > 2) ? argv[2] : "char_m.bps";
  const char* bop       = (argc > 3) ? argv[3] : "i";

  // Read the general polygons from the input files.
  CGAL::Timer timer;
  Bezier_polygon_set S1, S2;

  timer.start();


  if (! read_bezier(filename1, S1)) {
    std::cerr << "Failed to read " << filename1 << " ..." << std::endl;
    return 1;
  }

  if (! read_bezier(filename2, S2)) {
    std::cerr << "Failed to read " << filename2 << " ..." << std::endl;
    return 1;
  }

  timer.stop();
  std::cout << "Constructed the input polygons in " << timer.time()
            << " seconds." << std::endl << std::endl;

  std::cout << "Starting boolean operation..." << std::endl;
  timer.reset();
  timer.start();
  try {
    switch (bop[0]) {
      case 'i': S1.intersection(S2); break;
      case 'u': S1.join(S2); break;
    }
  }
  catch(std::exception const& x) {
    std::cout << "An exception occurred during the Boolean operation:"
              << x.what() << std::endl;
  }
  catch(...) {
    std::cout << "An exception occurred during the Boolean operation."
              << std::endl;
  }
  timer.stop();

  std::cout << "The " << ( bop[0] == 'i' ? "intersection" : "union" )
            << " computation took "
            << timer.time() << " seconds." << std::endl;

  return 0;
}

#endif