\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)

CGAL 4.3 - 2D Arrangements

All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Groups Pages
Arrangement_on_surface_2/generic_curve_data.cpp
// Associating a name attribute with segments using the generic curve-data
// traits.
#include "arr_rational_nt.h"
#include <CGAL/Cartesian.h>
#include <CGAL/Arr_segment_traits_2.h>
#include <CGAL/Arr_polyline_traits_2.h>
#include <CGAL/Arr_curve_data_traits_2.h>
#include <CGAL/Arrangement_2.h>
#include <string>
// Define a functor for concatenating name fields.
typedef std::string Name;
struct Merge_names
{
Name operator() (const Name& s1, const Name& s2) const
{
return (s1 + " " + s2);
}
};
typedef CGAL::Cartesian<Number_type> Kernel;
typedef CGAL::Arr_segment_traits_2<Kernel> Segment_traits_2;
typedef CGAL::Arr_polyline_traits_2<Segment_traits_2> Polyline_traits_2;
typedef Polyline_traits_2::Curve_2 Polyline_2;
typedef CGAL::Arr_curve_data_traits_2<Polyline_traits_2, Name, Merge_names>
Traits_2;
typedef Traits_2::Point_2 Point_2;
typedef Traits_2::Curve_2 Curve_2;
typedef Traits_2::X_monotone_curve_2 X_monotone_curve_2;
typedef CGAL::Arrangement_2<Traits_2> Arrangement_2;
int main ()
{
// Construct an arrangement of four polylines named A--D.
Arrangement_2 arr;
Point_2 points1[5] = {Point_2(0,0), Point_2(2,4), Point_2(3,3),
Point_2(4,4), Point_2(6,0)};
insert (arr, Curve_2 (Polyline_2 (points1, points1 + 5), "A"));
Point_2 points2[3] = {Point_2(1,5), Point_2(3,3), Point_2(5,5)};
insert (arr, Curve_2 (Polyline_2 (points2, points2 + 3), "B"));
Point_2 points3[4] = {Point_2(1,0), Point_2(2,2),
Point_2(4,2), Point_2(5,0)};
insert (arr, Curve_2 (Polyline_2 (points3, points3 + 4), "C"));
Point_2 points4[2] = {Point_2(0,2), Point_2(6,2)};
insert (arr, Curve_2 (Polyline_2 (points4, points4 + 2), "D"));
// Print all edges that correspond to an overlapping polyline.
Arrangement_2::Edge_iterator eit;
for (eit = arr.edges_begin(); eit != arr.edges_end(); ++eit) {
if (eit->curve().data().length() > 1) {
std::cout << "[" << eit->curve() << "] "
<< "named: " << eit->curve().data() << std::endl;
// Rename the curve associated with the edge.
arr.modify_edge (eit, X_monotone_curve_2 (eit->curve(), "overlap"));
}
}
return 0;
}