Circle Tangents in OpenSCAD

Some simple OpenSCAD to get the points for lines that are tangential to two arbitrary circles.

I found myself bodging this a lot so used Prof. Google to get some equations to do it properly.

Enjoy!

Update: I've been pointed to this thread where there's a very nice bit of code at the bottom that solves the problem in a different way and is probably easier to use! http://forum.openscad.org/Script-to-replicate-hull-and-minkoswki-for-CSG-export-import-into-FreeCAD-tp16537p16556.html