CGAL users discussion list

[Monique Teillaud <>]

Hi,

I don't remember details but I guess that we have followed the same 
conventions as the CGAL circular kernel, see
https://doc.cgal.org/latest/Manual/packages.html#PkgCircularKernel2 
The orientation is chosen to be globally consistent. 

I have checked the documentation quickly. As far as I can see, neither the 
traits concept
(https://doc.cgal.org/latest/Hyperbolic_triangulation_2/classHyperbolicDelaunayTriangulationTraits__2.html)
nor the two models (note that one of them is based on the abovementioned 
circular kernel) is explicitly saying anything on the orientation of circular 
arcs. There is no guarantee that undocumented properties stay the same 
forever, so, it might be risky to rely on them. 

Best,
--
Monique Teillaud 
https://members.loria.fr/Monique.Teillaud/
INRIA Nancy - Grand Est, LORIA 
Institut National de Recherche en Informatique et Automatique

----- Le 14 Juin 19, à 9:10, Stefan Witzel 

 a écrit :

> Hi again,
> 
> If I understand correctly in lines 135-136 of
> 
> Hyperbolic_triangulation_2/include/CGAL/internal/Hyperbolic_Delaunay_triangulation_traits_2_functions.h
> 
> the orientation of hyperbolic segments is chosen so that circular arcs
> are always (counter-?)clockwise, discarding potential combinatorial
> information. That is, a hyperbolic segment from p to q may end up
> going from q to p. Is this correct and is there a good reason for it?
> 
> Best,
> Stefan
>