The code can be downloaded from the
cgal-public-dev repository of CGAL.
Here is a direct link to the branch Periodic_4_hyperbolic_triangulation_2-IIordanov and here a direct link to the directory Periodic_4_hyperbolic_triangulation_2.
A package will be submitted for integration into CGAL as soon as the documentation is written.
Alternatively, download separate Maple sheets with calculations for...
...the elements of the fundamental octagon (vertices, midpoints...)
...rational dummy points
...the diameters of the empty disks for the dummy points (algebraic and rational)
...the proof of Theorem 1 in the paper
...the expressions of the translations around a vertex of the fundamental domain
...the algebraic degree of the Orientation predicate
...the algebraic degree of the InCircle predicate
...the algebraic degree of the SideOfOctagon predicate