\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.12.1 - 2D Triangulation
Triangulation_2/polylines_triangulation.cpp
#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
#include <CGAL/Polygon_2.h>
#include <CGAL/Constrained_Delaunay_triangulation_2.h>
#include <CGAL/Constrained_triangulation_plus_2.h>
#include <vector>
typedef CGAL::Polygon_2<K> Polygon_2;
typedef CDTP::Point Point;
typedef CDTP::Constraint_id Cid;
typedef CDTP::Vertex_handle Vertex_handle;
void
print(const CDTP& cdtp, Cid cid)
{
typedef CDTP::Vertices_in_constraint Vertices_in_constraint;
std::cout << "Polyline constraint:" << std::endl;
for(Vertices_in_constraint it = cdtp.vertices_in_constraint_begin(cid);
it !=cdtp.vertices_in_constraint_end(cid);
it++){
Vertex_handle vh = *it;
std::cout << vh->point() << std::endl;
}
}
void
contexts(const CDTP& cdtp)
{
CDTP::Subconstraint_iterator
beg = cdtp.subconstraints_begin(),
end = cdtp.subconstraints_end();
for(; beg!=end; ++beg){
Vertex_handle vp = beg->first.first, vq = beg->first.second;
if(cdtp.number_of_enclosing_constraints(vp, vq) == 2){
CDTP::Context_iterator cbeg = cdtp.contexts_begin(vp,vq),
cend = cdtp.contexts_end(vp,vq);
std::cout << "subconstraint " << vp->point() << " " << vq->point()
<< " is on constraints starting at:\n";
for(; cbeg != cend; ++cbeg){
CDTP::Context c = *cbeg;
std::cout << (*(c.vertices_begin()))->point() << std::endl;
}
}
}
}
int
main( )
{
CDTP cdtp;
cdtp.insert_constraint(Point(0,0), Point(1,1));
std::vector<Point> points;
points.push_back(Point(1,1));
points.push_back(Point(5,2));
points.push_back(Point(6,0));
points.push_back(Point(3,0));
Cid id1 = cdtp.insert_constraint(points.begin(), points.end());
print(cdtp, id1);
Polygon_2 poly;
poly.push_back(Point(2,3));
poly.push_back(Point(4,0));
poly.push_back(Point(5,0));
poly.push_back(Point(6,2));
Cid id2 = cdtp.insert_constraint(poly.vertices_begin(), poly.vertices_end(), true);
print(cdtp, id1);
print(cdtp, id2);
contexts(cdtp);
return 0;
}