CGAL users discussion list

[Dennis Endt <>]

Hi,

thanks for your reply.

That`s what I`m looking for:
Segment     t.segment ( Face_handle f, int i)

But this doesn`t exist. I don`t find it in the maunal and the compiler
only gives me two possibilities to define a segment:
Segment t.segment( Edge e)
Segment t.segment( const Cell handle c, int i, int j)

So plz tell me how can I get the edges/segments of a face where the face
should be a triangle? A small example woulb be very nice.

Best,
Dennis


Olivier Devillers schrieb:
> Dennis Endt a écrit :
>> Hi Andreas,
>>
>> I read the manual for another time and it became clear how I can get a
>> triangle of a facet. I think I understand how you define the geometry
>> and how I can work with them.
>>
>> But I miss the edges of a triangle. Can I only read out the points?
>>   
>
> It must be clear that you do not "read the triangle" from the
> triangulation.
> The triangle you get is constructed on the fly when you ask for it.
>
> From the manual I get  (but you said that you looked at it ;-)
>
>
> Triangle     t.triangle ( Face_handle f)     Returns the triangle
> formed by the three vertices of f.
> Precondition:     The face is finite.
> Segment     t.segment ( Face_handle f, int i)     Returns the line
> segment formed by the vertices ccw(i) and cw(i) of face f.
> Precondition:     0 i 2. The vertices ccw(i) and cw(i) of f are finite.
> Segment     t.segment ( Edge e)     Returns the line segment
> corresponding to edge e.
> Precondition:     e is a finite edge
> Segment     t.segment ( Edge_circulator ec)     Returns the line
> segment corresponding to edge *ec.
> Precondition:     *ec is a finite edge.
> Segment     t.segment ( Edge_iterator ei)     Returns the line segment
> corresponding to edge *ei.
> Precondition:     *ei is a finite edge.
> Point     t.circumcenter ( Face_handle f)     Compute the circumcenter
> of the face pointed to by f. This function is available only if the
> corresponding function is provided in the geometric traits.
>
>
> thus you can get Segment corresponding to an edge (but this segment is
> constructed when you ask for it)
> The only geometry stored in the trainagulation is a point for each
> finite vertex
>
>