CGAL 5.6.1 - 2D Arrangements
Arrangement_on_surface_2/unbounded_non_intersecting.cpp
// Constructing an arrangement of unbounded linear objects using the insertion
// function for non-intersecting curves.
#include <cassert>
#include "arr_linear.h"
#include "arr_print.h"
int main() {
Arrangement arr;
// Insert a line in the (currently single) unbounded face of the arrangement;
// then, insert a point that lies on the line splitting it into two.
X_monotone_curve c1 = Line(Point(-1, 0), Point(1, 0));
arr.insert_in_face_interior(c1, arr.unbounded_face());
Vertex_handle v = insert_point(arr, Point(0,0));
assert(! v->is_at_open_boundary());
// Add two more rays using the specialized insertion functions.
arr.insert_from_right_vertex(Ray(Point(0, 0), Point(-1, 1)), v); // c2
arr.insert_from_left_vertex(Ray(Point(0, 0), Point(1, 1)), v); // c3
// Insert three more interior-disjoint rays, c4, c5, and c6.
insert_non_intersecting_curve(arr, Ray(Point(0, -1), Point(-2, -2)));
insert_non_intersecting_curve(arr, Ray(Point(0, -1), Point(2, -2)));
insert_non_intersecting_curve(arr, Ray(Point(0, 0), Point(0, 1)));
print_unbounded_arrangement_size(arr);
// Print the outer CCBs of the unbounded faces.
int k = 1;
for (auto it = arr.unbounded_faces_begin(); it != arr.unbounded_faces_end();
++it)
{
std::cout << "Face no. " << k++ << "(" << it->is_unbounded() << ","
<< it->number_of_holes() << ")" << ": ";
Arrangement::Ccb_halfedge_const_circulator first = it->outer_ccb();
auto curr = first;
if (! curr->source()->is_at_open_boundary())
std::cout << "(" << curr->source()->point() << ")";
do {
Arrangement::Halfedge_const_handle e = curr;
if (! e->is_fictitious()) std::cout << " [" << e->curve() << "] ";
else std::cout << " [ ... ] ";
if (! e->target()->is_at_open_boundary())
std::cout << "(" << e->target()->point() << ")";
} while (++curr != first);
std::cout << std::endl;
}
return 0;
}