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[Hanjoerg Seybold <>]

Hello Olivier,
Thanks a lot for the answer. I was already thinking of something like this, 
but i thought there was a simpler answer ;)
merci
hj 


Olivier Devillers writes: 

> Hanjoerg Seybold a écrit :
> > Hi!
> > Nobody has an idea how to obtain the direction of infinite halfedges?
> > thanks hj
> > Hanjoerg Seybold writes:
> > > Hello!
> > > I am making calculations with voronoi diagrams. For my application i 
> > > have to intersect the unbounded edges/halfedges with a boundary given by 
> > > a polygon or a segment or line. After studying the manual and i am a bit 
> > > confused about the halfedge structure. 1. it is said that "Halfedges are 
> > > oriented edges", but i cannot find a
> > >   method how to access  the orientation.
> from source to target ! 
>
> > > 2. It is possibe to check if a halfedge IS a segment or ray. h.is_ray(),
> > >   but if the halfedge IS a ray, how can i access its features 
> > > (direction,
> > >   etc.)?
> I agree that such a function should be there. 
>
> Anyway you can get dual()->segment() to get the dual Delaunay edge
> and rotate it by 90 d. to get the direction 
>
> > > 3. My Problem is that i iterate through the halfedges and i want to know 
> > > if
> > >  a infinite halfedge intersects a polygon. For this i wanted to 
> > > construct
> > >  a  line ray etc out of the halfedge, but i dont know how to obtain the
> > >   direction in the case that the halfedge has only source OR target. Any 
> > > help would be welcome   hansjoerg
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