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#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polygon_mesh_processing/triangulate_hole.h>
#include <CGAL/utility.h>
#include <vector>
#include <iterator>
typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
typedef Kernel::Point_3 Point;
int main()
{
std::vector<Point> polyline;
polyline.push_back(Point( 1.,0.,0.));
polyline.push_back(Point( 0.,1.,0.));
polyline.push_back(Point(-1.,0.,0.));
polyline.push_back(Point( 1.,1.,0.));
// repeating first point (i.e. polyline.push_back(Point(1.,0.,0.)) ) is optional
// any type, having Type(int, int, int) constructor available, can be used to hold output triangles
typedef CGAL::Triple<int, int, int> Triangle_int;
std::vector<Triangle_int> patch;
patch.reserve(polyline.size() -2); // there will be exactly n-2 triangles in the patch
CGAL::Polygon_mesh_processing::triangulate_hole_polyline(
polyline,
std::back_inserter(patch));
for(std::size_t i = 0; i < patch.size(); ++i)
{
std::cout << "Triangle " << i << ": "
<< patch[i].first << " " << patch[i].second << " " << patch[i].third
<< std::endl;
}
// note that no degenerate triangles are generated in the patch
std::vector<Point> polyline_collinear;
polyline_collinear.push_back(Point(1.,0.,0.));
polyline_collinear.push_back(Point(2.,0.,0.));
polyline_collinear.push_back(Point(3.,0.,0.));
polyline_collinear.push_back(Point(4.,0.,0.));
std::vector<Triangle_int> patch_will_be_empty;
CGAL::Polygon_mesh_processing::triangulate_hole_polyline(
polyline_collinear,
back_inserter(patch_will_be_empty));
CGAL_assertion(patch_will_be_empty.empty());
return 0;
}
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