CGAL 5.1.3 - 2D Polyline Simplification
Polyline_simplification_2/points_and_vertices.cpp
#include <iostream>
#include <fstream>
#include <boost/config.hpp>
#include <boost/version.hpp>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polygon_2.h>
#include <CGAL/Polygon_with_holes_2.h>
#include <CGAL/Constrained_Delaunay_triangulation_2.h>
#include <CGAL/Constrained_triangulation_plus_2.h>
#include <CGAL/Polyline_simplification_2/simplify.h>
#if BOOST_VERSION >= 105600 && (! defined(BOOST_GCC) || BOOST_GCC >= 40500)
#include <CGAL/IO/WKT.h>
#endif
typedef CGAL::Polygon_2<K> Polygon_2;
typedef CGAL::Polygon_with_holes_2<K> Polygon_with_holes_2;
typedef PS::Vertex_base_2<K> Vb;
typedef CGAL::Triangulation_data_structure_2<Vb, Fb> TDS;
typedef CT::Point Point;
typedef CT::Constraint_id Constraint_id;
typedef CT::Constraint_iterator Constraint_iterator;
typedef CT::Vertices_in_constraint_iterator Vertices_in_constraint_iterator;
typedef CT::Points_in_constraint_iterator Points_in_constraint_iterator;
typedef PS::Stop_below_count_ratio_threshold Stop;
typedef PS::Squared_distance_cost Cost;
void print(const CT& ct, Constraint_id cid)
{
std::cout << "simplified polyline" <<std::endl;
for(Vertices_in_constraint_iterator vit =
ct.vertices_in_constraint_begin(cid);
vit != ct.vertices_in_constraint_end(cid);
++vit){
std::cout << (*vit)->point() << std::endl ;
}
std::cout << "original points" <<std::endl;
for(Points_in_constraint_iterator pit =
ct.points_in_constraint_begin(cid);
pit != ct.points_in_constraint_end(cid);
++pit){
std::cout << *pit << std::endl ;
}
}
int main(int argc, char* argv[])
{
std::ifstream ifs( (argc==1)?"data/polygon.wkt":argv[1]);
#if BOOST_VERSION >= 105600 && (! defined(BOOST_GCC) || BOOST_GCC >= 40500)
const bool remove_points = false;
CT ct;
Polygon_with_holes_2 P;
Constraint_id cid;
std::size_t largest = 0;
const Polygon_2& poly = P.outer_boundary();
Constraint_id cid2 = ct.insert_constraint(poly);
if(poly.size() > largest){
cid = cid2;
}
}
PS::simplify(ct, cid, Cost(), Stop(0.5), remove_points);
print(ct, cid);
PS::simplify(ct, cid, Cost(), Stop(0.5), remove_points);
ct.remove_points_without_corresponding_vertex(cid);
print(ct, cid);
#else
ifs.close();
#endif
return 0;
}