CGAL 5.5  2D Alpha Shapes

The concept AlphaShapeVertex_2
describes the requirements for the base vertex of an alpha shape.
TriangulationVertexBase_2
, if the underlying triangulation of the alpha shape is a Delaunay triangulation.
RegularTriangulationVertexBase_2
, if the underlying triangulation of the alpha shape is a regular triangulation.
Periodic_2TriangulationVertexBase_2
, if the underlying triangulation of the alpha shape is a periodic triangulation.
CGAL::Alpha_shape_vertex_base_2
(templated with the appropriate triangulation vertex base class). Types  
typedef unspecified_type  FT 
A coordinate type. More...  
Creation  
AlphaShapeVertex_2 ()  
default constructor.  
AlphaShapeVertex_2 (Point p)  
constructor setting the point.  
AlphaShapeVertex_2 (Point p, const Face_handle &ff)  
constructor setting the point associated to and an incident face.  
Access Functions  
std::pair< FT, FT >  get_range () 
returns two alpha values \( \alpha_1 \leq\alpha_2\), such as for \( \alpha\) between \( \alpha_1\) and \( \alpha_2\), the vertex is attached but singular, and for \( \alpha\) upper \( \alpha_2\), the vertex is regular.  
Modifiers  
void  set_range (std::pair< FT, FT > I) 
sets the alpha values \( \alpha_1 \leq\alpha_2\), such as for \( \alpha\) between \( \alpha_1\) and \( \alpha_2\), the vertex is attached but singular, and for \( \alpha\) upper \( \alpha_2\), the vertex is regular.  
A coordinate type.
The type must provide a copy constructor, assignment, comparison operators, negation, multiplication, division and allow the declaration and initialization with a small integer constant (cf. requirements for number types). An obvious choice would be coordinate type of the point class.