\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 5.0.2 - 3D Triangulation Data Structure
TDS_3/linking_2d_and_3d.cpp
#include <CGAL/Triangulation_data_structure_2.h>
#include <CGAL/Triangulation_data_structure_3.h>
#include <cassert>
// declare the 2D vertex base type, parametrized by some 3D TDS.
template < typename T3, typename Vb = CGAL::Triangulation_ds_vertex_base_2<> >
class My_vertex_2;
// declare the 3D vertex base type, parametrized by some 2D TDS.
template < typename T2, typename Vb = CGAL::Triangulation_ds_vertex_base_3<> >
class My_vertex_3;
// Then, we have to break the dependency cycle.
// we need to refer to a dummy 3D TDS.
Dummy_tds_3;
// the 2D TDS, initially plugging a dummy 3D TDS in the vertex type
// (to break the dependency cycle).
typedef CGAL::Triangulation_data_structure_2<My_vertex_2<Dummy_tds_3> > TDS_2;
// the 3D TDS, here we can plug the 2D TDS directly.
template < typename T3, typename Vb >
class My_vertex_2
: public Vb
{
public:
typedef typename Vb::Face_handle Face_handle;
template <typename TDS2>
struct Rebind_TDS {
typedef typename Vb::template Rebind_TDS<TDS2>::Other Vb2;
// we also have to break the cycle here by hardcoding TDS_3 instead of T3.
typedef My_vertex_2<TDS_3, Vb2> Other;
};
My_vertex_2() {}
My_vertex_2(Face_handle f) : Vb(f) {}
// we store a vertex handle of the 3D TDS.
typename T3::Vertex_handle v3;
};
template < typename T2, typename Vb >
class My_vertex_3
: public Vb
{
public:
typedef typename Vb::Cell_handle Cell_handle;
template <typename TDS2>
struct Rebind_TDS {
typedef typename Vb::template Rebind_TDS<TDS2>::Other Vb2;
typedef My_vertex_3<T2, Vb2> Other;
};
My_vertex_3() {}
My_vertex_3(Cell_handle c) : Vb(c) {}
// we store a vertex handle of the 2D TDS.
typename T2::Vertex_handle v2;
};
int main() {
TDS_2 t2;
TDS_3 t3;
TDS_2::Vertex_handle v2 = t2.insert_dim_up();
TDS_3::Vertex_handle v3 = t3.insert_increase_dimension();
v2->v3 = v3;
v3->v2 = v2;
assert(t2.is_valid());
assert(t3.is_valid());
return 0;
}