## AlphaShapeFace_2

### Definition

### Refines

TriangulationFaceBase_2.

### Types

AlphaShapeFace_2::Interval_3
| A container type to get (and put) the three special values (1, 2, 3) associated with an alpha shape edge.
AlphaShapeFace_2::FT
| A type to hold a coordinate type class. 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

### Creation

| advanced |

AlphaShapeFace_2 f;
| default constructor.
AlphaShapeFace_2 f ( void* v0, void* v1, void* v2);
| constructor setting the incident vertices.

AlphaShapeFace_2 f ( | void* v0, void* v1, void* v2, void* n0, void* n1, void* n2);

| constructor setting the incident vertices and the neighboring faces.

| advanced |

### Access Functions

Interval_3 | f.get_ranges ( int i)
|  | returns the interval associated with the edge indexed with i, which contains three alpha values 1 2 3, such as for between 1 and 2, the edge indexed with i is attached but singular, for between 2 and 3, the edge is regular, and for greater than 3, the edge is interior.
FT | f.get_alpha () | return the alpha value, under which the alpha shape contains the face.

### Modifiers

| advanced |

void | f.set_ranges ( int i, Interval_3 V)
|  | sets the interval associated with the edge indexed with i, which contains three alpha values 1 2 3, such as for between 1 and 2, the edge indexed with i is attached but singular, for between 2 and 3, the edge is regular, and for greater than 3, the edge is interior.
void | f.set_alpha ( FT A)
|  | sets the alpha value, under which the alpha shape contains the face.

| advanced |