CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 02/20/2015 08:48 PM, Marius Kintel wrote:
> Hi,
>
> The rollback code is never reached in cases where scd.visit_shell_objects() 
> throws an exception.
> e.g. violated intersection constraint in Constrained_triangulation_2.
>
> We temporarily worked around this by explicitly catching those exceptions in 
> our forked version of the Build_polyhedron class.
> I haven’t tested Giles’ variant, but that looks a lot cleaner that our 
> attempt.

I'll have deeper look.

In the meantime you can try:
#define CGAL_CT2_WANTS_TO_HAVE_EXTRA_ACTION_FOR_INTERSECTING_CONSTRAINTS
#define CGAL_CDT2_EXTRA_ACTION_FOR_INTERSECTING_CONSTRAINTS throw 
WhatEverException;

This will allow you to throw an exception if constraints intersect.

Sebastien.

>   -Marius
>
> On Feb 19, 2015, at 05:35 AM, Sebastien Loriot (GeometryFactory) 
> <>
>  wrote:
>
> > Please check whether the following patch solves your problem:
> > --- a/Nef_3/include/CGAL/Nef_polyhedron_3.h
> > +++ b/Nef_3/include/CGAL/Nef_polyhedron_3.h
> > @@ -824,6 +824,7 @@ protected:
> >         if(skip_volumes-- <= 0)
> >           scd.visit_shell_objects(SFace_const_handle(c->shells_begin()),V);
> >        B.end_surface();
> > +      if ( B.error() ) B.rollback();
> >      }
> >
> >    };
> > @@ -977,6 +978,7 @@ protected:
> >        Visitor V(B,omit_vertex, scd,VI);
> >        scd.visit_shell_objects(sf, V);
> >        B.end_surface();
> > +      if ( B.error() ) B.rollback();
> >      }
> >
> >    };