Classes that help assign a topology to the cells. The interface {@link ch.unizh.ini.friend.topology.Retinotopic} means that the object has a {@link ch.unizh.ini.friend.topology.RetinotopicLocation} (basically a Point2D).

Static methods in {@link ch.unizh.ini.friend.topology.RetinotopicLocation} can find cells in the same or different layer that are corresponding, in a certain direction, etc.

{@link ch.unizh.ini.friend.topology.HexDirection} specifies a wrapping direction in the base hex coordinate system.

In order to use this notion of retinotopy, cells must correctly implement {@link ch.unizh.ini.friend.topology.Retinotopic}, e.g., they must have a {@link ch.unizh.ini.friend.topology.RetinotopicLocation} and correctly set it. This initialization is done, for example, in the static methods that construct arrays of cells from a preceeding layer.

The package UML is