CGAL users discussion list

[Winnie Hellmann <>]

Dear list,

I am trying to find all vertices and edges of a triangulation 
(Constrained_Delaunay_triangulation_2) that intersect with an vertical 
upward ray with given x-coordinate. My first approach was to use the 
Triangulation_line_face_circulator_2, which fails in case the ray is 
collinear to a vertical edge on the left side of the triangulation's 
convex hull (see [1] and [2], and alo l2 in [3]).

Does CGAL provide a linear time possibility to do a vertical ray shoot 
in a triangulation? Copying the whole triangulation (e.g. into an 
arrangement) is not an option.

Thank you in advance,
Winnie Hellmann

[1] http://www.winniehell.de/tmp/cgal/input.svg
[2] http://www.winniehell.de/tmp/cgal/triangulation.svg
[3] 
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Triangulation_2_ref/Class_Triangulation_2.html#Triangulation_ref_Fig_Line_face_circulator