CGAL 5.2.1 - 3D Triangulations
Triangulation_3/segment_simplex_traverser_3.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Delaunay_triangulation_3.h>
#include <assert.h>
#include <iostream>
#include <fstream>
#include <string>
#include <CGAL/IO/read_xyz_points.h>
#include <CGAL/Random.h>
#define CGAL_TRIANGULATION_3_VERBOSE_TRAVERSER_EXAMPLE
// Define the kernel.
typedef Kernel::Point_3 Point_3;
// Define the structure.
typedef DT::Segment_simplex_iterator Segment_simplex_iterator;
int main(int argc, char* argv[])
{
const char* fname = (argc>1) ? argv[1] : "data/blobby.xyz";
std::vector<Point_3> points;
std::ifstream stream(fname);
if (!stream ||
!CGAL::read_xyz_points(stream, std::back_inserter(points)))
{
std::cerr << "Error: cannot read file " << fname << std::endl;
return EXIT_FAILURE;
}
// Construct the Delaunay triangulation.
DT dt( points.begin(), points.end() );
assert( dt.is_valid() );
CGAL::Random rng;
std::cout << "Random seed is " << CGAL::get_default_random().get_seed() << std::endl;
unsigned int nb_cells = 0, nb_facets = 0, nb_edges = 0, nb_vertex = 0;
// Construct a traverser and use begin/end iterators
Point_3 p1(rng.get_double(-0.48, 0.31),
rng.get_double(-0.22, 0.22),
rng.get_double(-0.19, 0.19));
Point_3 p2(rng.get_double(-0.48, 0.31),
rng.get_double(-0.22, 0.22),
rng.get_double(-0.19, 0.19));
Segment_simplex_iterator st = dt.segment_traverser_simplices_begin(p1, p2);
Segment_simplex_iterator stend = dt.segment_traverser_simplices_end();
for (; st != stend; ++st)
{
if (st->dimension() == 3) ++nb_cells;
else if (st->dimension() == 2) ++nb_facets;
else if (st->dimension() == 1) ++nb_edges;
else if (st->dimension() == 0) ++nb_vertex;
}
#ifdef CGAL_TRIANGULATION_3_VERBOSE_TRAVERSER_EXAMPLE
std::cout << "While traversing from " << p1 << " to " << p2 << std::endl;
std::cout << "\tcells : " << nb_cells << std::endl;
std::cout << "\tfacets : " << nb_facets << std::endl;
std::cout << "\tedges : " << nb_edges << std::endl;
std::cout << "\tvertices : " << nb_vertex << std::endl;
std::cout << std::endl << std::endl;
#endif
// Construct a traverser and use range-iterator
nb_cells = 0, nb_facets = 0, nb_edges = 0, nb_vertex = 0;
for (const Simplex& s : dt.segment_traverser_simplices(p1, p2))
{
if (s.dimension() == 3) ++nb_cells;
else if (s.dimension() == 2) ++nb_facets;
else if (s.dimension() == 1) ++nb_edges;
else if (s.dimension() == 0) ++nb_vertex;
}
#ifdef CGAL_TRIANGULATION_3_VERBOSE_TRAVERSER_EXAMPLE
std::cout << "While traversing from " << p1 << " to " << p2 << std::endl;
std::cout << "\tcells : " << nb_cells << std::endl;
std::cout << "\tfacets : " << nb_facets << std::endl;
std::cout << "\tedges : " << nb_edges << std::endl;
std::cout << "\tvertices : " << nb_vertex << std::endl;
std::cout << std::endl << std::endl;
#endif
return 0;
}