CGAL users discussion list

[Benoît Presles <>]

> > Hello Everybody,
> >
> > I think a new bug could be present in the "Alpha_shape_2" class (the
> > problem can be reproduced by using the list of points "fin" attached
> > in this email).
> >
> > First, I compute the alpha shape (GENERAL MODE).
> > Second, I print the segments which belongs to the alpha shape.
> > Third, I print the points which belongs to the alpha shape
> > (Alpha_shape_vertices_iterator).
> >
> > The problem is that I get too many points printed, for example the
> > point (60,50) doesn't belong to the alpha shape but is printed.
> >
> > Output of the program:
> > Reading 11 points from file
> > Alpha Shape computed
> > 7 alpha shape edges
> > 7 0 4 4
> > 4 4 1 0
> > 0 0 1 0
> > 1 0 2.5 0
> > 2.5 0 4.5 0
> > 4.5 0 7 0
> > 16 16 20 20
> > as_it=4.5 0
> > as_it=2.5 0
> > as_it=4 4
> > as_it=7 0
> > as_it=1 0
> > as_it=0 0
> > as_it=8 12
> > as_it=16 16
> > as_it=20 20
> > as_it=40 40
> > as_it=60 50
>
> It behaves as expected, vertices printed are either REGULAR or SINGULAR
> in GENERAL mode and REGULAR in REGULARIZED mode.

Maybe I don't understand something but in my point of view, in both 
cases (GENERAL or REGULARIZED mode), the vertices printed with 
"Alpha_shape_vertices_iterator" should be the same as the one printed 
with "Alpha_shape_edges_iterator" and it is not the case here.

Thank you very much for your help,
Ben_P

> S.