CGAL 6.1.2 - 2D Arrangements: Arrangement_on_surface_2/consolidated_curve_data.cpp

CGAL 6.1.2 - 2D Arrangements

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Arrangement_on_surface_2/consolidated_curve_data.cpp
// Associating a color attribute with segments using the consolidated
// curve-data traits.
#include <CGAL/Arr_consolidated_curve_data_traits_2.h>
#include "arr_exact_construction_segments.h"
enum Segment_color {RED, BLUE};
using Data_traits =
CGAL::Arr_consolidated_curve_data_traits_2<Traits, Segment_color>;
using Colored_segment = Data_traits::Curve_2;
using Colored_arr = CGAL::Arrangement_2<Data_traits>;
int main() {
Colored_arr arr;
// Construct an arrangement containing three RED line segments.
insert(arr, Colored_segment(Segment(Point(-1, -1), Point(1, 3)), RED));
insert(arr, Colored_segment(Segment(Point(2, 0), Point(3, 3)), RED));
insert(arr, Colored_segment(Segment(Point(0, 3), Point(2, 5)), RED));
// Insert three BLUE line segments.
insert(arr, Colored_segment(Segment(Point(-1, 3), Point(4, 1)), BLUE));
insert(arr, Colored_segment(Segment(Point(-1, 0), Point(4, 1)), BLUE));
insert(arr, Colored_segment(Segment(Point(-2, 1), Point(1, 4)), BLUE));
// Go over all vertices and print just the ones corresponding to intersection
// points between RED segments and BLUE segments. Skip endpoints of
// overlapping sections.
for (auto vit = arr.vertices_begin(); vit != arr.vertices_end(); ++vit) {
// Go over the current-vertex incident-halfedges and examine their colors.
bool has_red = false, has_blue = false;
Colored_arr::Halfedge_around_vertex_const_circulator eit, first;
eit = first = vit->incident_halfedges();
do {
// Get the color of the current halfedge.
if (eit->curve().data().size() == 1) {
Segment_color color = eit->curve().data().front();
if (color == RED) has_red = true;
else if (color == BLUE) has_blue = true;
}
} while (++eit != first);
// Print the vertex only if incident RED and BLUE edges were found.
if (has_red && has_blue) {
std::cout << "Red intersect blue at (" << vit->point() << ")\n";
}
}
// Locate the edges that correspond to a red-blue overlap.
for (auto eit = arr.edges_begin(); eit != arr.edges_end(); ++eit) {
// Go over the incident edges of the current vertex and examine their colors.
bool has_red{false}, has_blue{false};
for (auto it = eit->curve().data().begin(); it != eit->curve().data().end();
++it)
{
if (*it == RED) has_red = true;
else if (*it == BLUE) has_blue = true;
}
// Print the edge only if it corresponds to a red-blue overlap.
if (has_red && has_blue)
std::cout << "Red overlap blue at [" << eit->curve() << "]\n";
}
return 0;
}
CGAL::Arr_consolidated_curve_data_traits_2
The class Arr_consolidated_curve_data_traits_2 is a model of the concept AosTraits_2,...
Definition: Arr_consolidated_curve_data_traits_2.h:27
CGAL::Arrangement_2
Definition: Arrangement_2.h:57