CGAL 5.6.1 - 2D Arrangements
Arrangement_on_surface_2/rational_functions.cpp
// Constructing an arrangement of arcs of rational functions.
#include <CGAL/config.h>
#ifndef CGAL_USE_CORE
#include <iostream>
int main() {
std::cout << "Sorry, this example needs CORE ..." << std::endl;
return 0;
}
#else
#include "arr_rat_functions.h"
#include "arr_print.h"
int main() {
CGAL::IO::set_pretty_mode(std::cout); // for nice printouts.
// Define a traits class object and a constructor for rational functions.
Traits traits;
auto construct = traits.construct_x_monotone_curve_2_object();
// Define a polynomial representing x.
Polynomial x = CGAL::shift(Polynomial(1), 1);
// Define a container storing all arcs.
std::vector<Traits::X_monotone_curve_2> arcs;
// Create an arc (C1) supported by the polynomial y = x^4 - 6x^2 + 8,
// defined over the (approximate) interval [-2.1, 2.1].
Polynomial P1 = CGAL::ipower(x,4) - 6*x*x + 8;
Alg_real l(Bound(-2.1)), r(Bound(2.1));
arcs.push_back(construct(P1, l, r));
// Create an arc (C2) supported by the function y = x / (1 + x^2),
// defined over the interval [-3, 3].
Polynomial P2 = x;
Polynomial Q2 = 1 + x*x;
arcs.push_back(construct(P2, Q2, Alg_real(-3), Alg_real(3)));
// Create an arc (C3) supported by the parbola y = 8 - x^2,
// defined over the interval [-2, 3].
Polynomial P3 = 8 - x*x;
arcs.push_back(construct(P3, Alg_real(-2), Alg_real(3)));
// Create an arc (C4) supported by the line y = -2x,
// defined over the interval [-3, 0].
Polynomial P4 = -2*x;
arcs.push_back(construct(P4, Alg_real(-3), Alg_real(0)));
// Construct the arrangement of the four arcs.
Arrangement arr(&traits);
insert(arr, arcs.begin(), arcs.end());
print_arrangement(arr);
return 0;
}
#endif