CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 01/31/2012 01:40 PM, Winnie Hellmann wrote:
> > Because the typo is consistently used in the code :)
> That's why I love auto completion. ;-)
>
> > > I want to sort my arrangement vertices by y-coordinate using a sweep
> > > line.
> So this leaves me with the question: Can I do a sweep line inside an
> arrangement in y-direction? As far as I have seen the Basic_sweep_line_2
> does sweeping in x-direction, but I haven't found any documentation for
> this class.

That's doable by providing another model of ArrangementTraits_2 to
handle that. In that traits, you need to define you own functors
Make_x_monotone_2, Compare_x_2 ...
In each functor you can reuse existing implementation and swap usage of
x and y. This is definitely not an easy solution.

The lazy solution is to have a preprocessing step to convert your input
by swapping x and y coordinates of points (and use handmade global
functions get_x(Point_2),get_y(Point_2) to avoid confusion in the rest
of your code).


Sebastien.




http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Arrangement_on_surface_2_ref/Concept_ArrangementTraits_2.html
> Thanks,
> Winnie Hellmann