CGAL users discussion list

[Ashwin Nanjappa <>]

Hi Khuong,

> 1. Where can I find the manual reference for X_handle (e.g, Face_handle,
> Vertex_handle...). For example, in the implementation
> examples/Segment_Delaunay_graph_2/sdg-voronoi-edges.cpp, the author called
> function site() SDG2::Vertex_handle, but I couldn't find any reference to
> SDG2::Vertex_handle.

A handle is like a pointer to an undelying object. A Vertex_handle is
a pointer to a vertex and so on.
See:
<http://www.cgal.org/Manual/3.3.1/doc_html/cgal_manual/Handle_ref/Concept_Handle.html>

The page says: "A Handle is akeen to a pointer to an object providing
the dereference operator". The "akeen" should be "akin" :-)

> 2. I couldn't find the detail about the manual reference of the
> Segment_Delaunay_graph_2::Edge (and Edge object in general). For example, in
> the same file above, the author call e.first, e.second....No reference found
> either!!!

The edge object is a pair.
See:
<http://www.cgal.org/Manual/3.4/doc_html/cgal_manual/TDS_2_ref/Concept_TriangulationDataStructure_2.html>

"""
typedef std::pair<Face_handle,int>
Edge;   The edge type. The Edge(f,i) is edge common to faces f and
f.neighbor(i). It is also the edge joining the vertices vertex(cw(i))
and vertex(ccw(i)) of f.
"""

> 3. I'd like to extract the faces with associated edges of the segment
> voronoi diagram. Could you guy tell me how to proceed? I'm completely lost
> in the CGAL's manual reference!!!

Could you elaborate?

~ash