Hi Peter, Thanks for your interest in GGL, and for trying to integrate it into your project. Lines and rays don't exist yet in GGL indeed. Adding them would basically consist in defining the corresponding concepts (like for polygon, segment, etc...) and then specialize the distance and intersection (to start with) algorithms for them, which is completely feasible. I'm personnally more video games oriented so I have already thought about the need of such things actually. As for directions, it's not there just because we didn't need it until now (there only exist a notion of orientation for points ranges traversal). I guess it would only be a traits to define and to use in algorithms that needed it. So to summarize, all those things are not yet there, but can easily be added. HTH Bruno