Delaunay triangulation constrained

Hello everyone,
I start a project that gives me a lot of questions.
The goal is to be a lanscape, with a perfect geometry mesh *.

I want to create a Delaunay triangulation constrained to points and curves.

I leave a link in French interest in understanding the stress of a mesh.

# http://www.kaddour.com/chap4/chap4.htm _toc420738722

* a constraint triangulation must respect the topology of the site (voronoy??)

thanks a lot for your helping.