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/**
* SFCGAL
*
* Copyright (C) 2012-2013 Oslandia <infos@oslandia.com>
* Copyright (C) 2012-2013 IGN (http://www.ign.fr)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include <fstream>
#include <CGAL/Cartesian.h>
#include <CGAL/Point_2.h>
#include <CGAL/Point_3.h>
#include <CGAL/Segment_2.h>
#include <CGAL/Segment_3.h>
#include <CGAL/Polygon_2.h>
#include <CGAL/Polygon_with_holes_2.h>
typedef CGAL::Cartesian< double > Kernel ;
typedef Kernel::Vector_2 Vector_2 ;
typedef Kernel::Vector_3 Vector_3 ;
typedef Kernel::Point_2 Point_2 ;
typedef Kernel::Point_3 Point_3 ;
typedef CGAL::Segment_2< Kernel > Segment_2 ;
typedef CGAL::Segment_3< Kernel > Segment_3 ;
typedef CGAL::Polygon_2< Kernel > Polygon_2 ;
typedef CGAL::Polygon_with_holes_2< Kernel > Polygon_with_holes_2 ;
#include <CGAL/Delaunay_triangulation_2.h>
#include <CGAL/Triangulation_vertex_base_with_info_2.h>
//-- Info on vertex (unsigned int, an idenfier)
typedef CGAL::Triangulation_vertex_base_with_info_2< unsigned int, Kernel > Vb ;
typedef CGAL::Triangulation_data_structure_2< Vb > Tds ;
//-- Triangulation
typedef CGAL::Delaunay_triangulation_2< Kernel, Tds > Delaunay_triangulation_2 ;
//-- point generator
#include <CGAL/point_generators_2.h>
typedef CGAL::Creator_uniform_2< double, Point_2 > Creator_2;
/**
* Generate a terrain and export to wavefront obj format
*/
int main()
{
std::ofstream ofs("triangulation2.obj");
if ( ! ofs.good() ){
std::cout << "can't open file" << std::endl;
return 1 ;
}
const size_t n = 1000 ;
CGAL::Random_points_in_disc_2< Point_2, Creator_2 > g( 5.0 );
//-- triangulate points
Delaunay_triangulation_2 tri;
// create points and associates ids
std::vector< Point_2 > points;
for ( size_t i = 0; i < n; i++ ){
Point_2 point2d = *(++g) ;
Delaunay_triangulation_2::Vertex_handle v = tri.insert( point2d );
v->info() = i ;
points.push_back( point2d );
}
// print vertices
ofs << "# " << tri.number_of_vertices() << " vertices"<< std::endl ;
for ( size_t i = 0; i < n; i++ ){
ofs << "v " << points[i] << " 0.0" << std::endl;
}
// print faces
ofs << "# " << tri.number_of_faces() << " faces"<< std::endl ;
//-- print triangles
// warning : Delaunay_triangulation_2::All_faces_iterator iterator over infinite faces
for ( Delaunay_triangulation_2::Finite_faces_iterator it = tri.finite_faces_begin();
it != tri.finite_faces_end(); ++it )
{
size_t ia = it->vertex(0)->info();
size_t ib = it->vertex(1)->info();
size_t ic = it->vertex(2)->info();
assert( it->is_valid() );
assert ( ia < tri.number_of_vertices() || ib < tri.number_of_vertices() || ic < tri.number_of_vertices() ) ;
ofs << "f " << ( ia + 1 ) << " " << ( ib + 1 ) << " " << ( ic + 1 ) << std::endl;
}
return 0;
}
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