Based on discussion of the current Point/Vector API in
GEOMETRY-14 and research into other geometric libraries, I think we should remove the Euclidean Point?D classes and make Vector?D also implement Point. This will end up being similar to the previous commons-math design but avoids the issue raised in MATH-1284 since the Point and Vector interfaces are not related. They just happen to be implemented by the same class, which we're calling Vector?D since a vector can be used to indicate a point (by adding it to the origin).
In the course of trying this out this design, I ended up removing 7 classes and simplifying several methods. I think that's a good indicator that this is a good design choice.
Pull request: https://github.com/apache/commons-geometry/pull/15