The concept AlphaShapeVertex_2
describes the requirements for the base vertex of an alpha shape.
 Refines
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
 Has Models:
CGAL::Alpha_shape_vertex_base_2
(templated with the appropriate triangulation vertex base class).

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.



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.


◆ FT
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.