Replying to paoloC:
d.geodesic and d.rhumbline are two interesting tools, especially
in educational courses, but they are no longer supported in grass
7.0.
They are still in 7.0. Interactive mode has been removed, and coor= from the command line has been added.
Is it possible to have them in wxGUI ?
I assume the GUI has some sort of buttons for them, but I can't say for sure where to look. Try the overlays section of the Map Display window.
Or, better, two analogous tools like e.g.: v.geodesic and
v.rhumbline ?
maybe not to hard to adapt the code..
regards,
Hamish