\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.13.2 - dD Triangulations
triangulation_data_structure_static.cpp
#include <CGAL/Triangulation_data_structure.h>
#include <CGAL/assertions.h>
#include <vector>
int main()
{
TDS S;
CGAL_assertion( 7 == S.maximal_dimension() );
CGAL_assertion( -2 == S.current_dimension() );
CGAL_assertion( S.is_valid() );
std::vector<TDS::Vertex_handle> V(10);
V[0] = S.insert_increase_dimension(); //insert first vertex
CGAL_assertion( -1 == S.current_dimension() );
for( int i = 1; i <= 5; ++i )
V[i] = S.insert_increase_dimension(V[0]);
// the first 6 vertices have created a triangulation
// of the 4-dimensional topological sphere
// (the boundary of a five dimensional simplex).
CGAL_assertion( 4 == S.current_dimension() );
CGAL_assertion( 6 == S.number_of_vertices() );
CGAL_assertion( 6 == S.number_of_full_cells() );
TDS::Full_cell_handle c = V[5]->full_cell();
V[6] = S.insert_in_full_cell(c);
// full cell c is split in 5
CGAL_assertion( 7 == S.number_of_vertices() );
CGAL_assertion( 10 == S.number_of_full_cells() );
c = V[3]->full_cell();
TDS::Facet ft(c, 2); // the Facet opposite to vertex 2 in c
V[7] = S.insert_in_facet(ft);
// facet ft is split in 4 and the two incident cells are split accordingly
CGAL_assertion( 8 == S.number_of_vertices() );
CGAL_assertion( 16 == S.number_of_full_cells() );
c = V[3]->full_cell();
TDS::Face face(c);
// meant to contain the edge joining vertices 2 and 4 of full_cell c
face.set_index(0, 2); // namely vertex 2
face.set_index(1, 4); // and vertex 4
V[8] = S.insert_in_face(face);
// face is split in 2, and all incident full cells also
CGAL_assertion( S.is_valid() );
TDS::Full_cell_handle hole[2];
hole[0] = V[8]->full_cell();
hole[1] = hole[0]->neighbor(0);
// the hole is made of two adjacent full cells
ft = TDS::Facet(hole[0], 1); // a face on the boundary of hole[0]
V[9] = S.insert_in_hole(hole, hole+2, ft);
// the hole is triangulated by linking a new vertex to its boundary
CGAL_assertion( S.is_valid() );
return 0;
}