The class Alpha_status<NT> is a small data strructure to store the critical alpha values of faces of an alpha shape. Each face has three critical alpha values, called alpha_min, alpha_mid and alpha_max in increasing order. The face will be exterior for any alpha_min, singular for alpha_min alpha_mid, regular for alpha_mid alpha_max and interior for alpha_max . The value alpha_min is undefined for faces which are not Gabriel faces and therefore do not appear in the alpha complex without any of their including face. The value alpha_max is undefined for convex hull faces which can never be interior, The data structure also includes two boolean to mark if the face is a Gabriel face or a convex hull face.
The class Alpha_status<NT> is paremetrized by a number type NT.
#include <CGAL/Alpha_shape_cell_base_3.h>
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default constructor.
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