The class Triangulation_data_structure_2<Vb,Fb> is a model for the TriangulationDataStructure_2 concept. It can be used to represent an orientable 2D triangulation embedded in a space of any dimension.
The vertices and faces are stored in two nested containers, which are implemented using CGAL::Compact_container. The class may offer some flexibility for the choice of container in the future, in the form of additional template parameters.
#include <CGAL/Triangulation_data_structure_2.h>
In addition to the interface documented in the concept, the class offers the following types and functions.
typedef CGAL::Compact_container<Vertex>  
Vertex_range;  Vertex container type.  
typedef CGAL::Compact_container<Face>  
Face_range;  Face container type. 
In addition to the modifiers required by the TriangulationDataStructure_2 concept, the Triangulation_data_structure_2<Vb,Fb> class supports also the modifiers below. Note also that the modifiers below guarantee the combinatorial validity of the resulting data structure.
Vertex_handle  tds.join_vertices ( Face_handle f, int i)  
Joins
the vertices that are endpoints of the edge (f,i). It returns
a vertex handle to common vertex (see
Fig. 38.6).
 
Vertex_handle  tds.join_vertices ( Edge e)  Joins the vertices that are endpoints of the edge e. It returns a vertex handle to common vertex.  
Vertex_handle  tds.join_vertices ( Edge_iterator eit)  
Joins the vertices that are endpoints of the edge *eit. It returns a vertex handle to common vertex.  
Vertex_handle  tds.join_vertices ( Edges_circulator ec)  
Joins the vertices that are endpoints of the edge *ec. It returns a vertex handle to common vertex.  
boost::tuples::tuple<Vertex_handle, Vertex_handle, Face_handle, Face_handle>  
tds.split_vertex ( Vertex_handle v, Face_handle f1, Face_handle f2)  
Splits the vertex v into two vertices v1 and
v2. The common faces f and g of v1 and
v2 are created after (in the counterclockwise sense) the
faces f1 and f2. The 4tuple (v1,v2,f,g) is
returned (see Fig. 38.6).
 
Vertex_handle  tds.insert_degree_2 ( Face_handle f, int i)  
Inserts a degree two vertex and two faces adjacent to it that have two common edges. The edge defined by the face handle f and the integer i is duplicated. It returns a handle to the vertex created (see Fig. 38.7).  
void  tds.remove_degree_2 ( Vertex_handle v)  
Removes a degree 2
vertex and the two faces adjacent to it. The two edges of the star of
v that are not incident to it are collapsed
(see Fig. 38.7).
