Worked at improving the 2D offsetting tool.
Added code to generate interior offsets to shapes. Found a very interesting classifier class: IntTools_Context that among other methods has IsValidPointForFace that classifies the position of a point related to a face.
Tried also improving the external shape offset to generate the same shape and not rounded shape duplications but couldn't find a possibility to implement it. Some custom algorithm needs to be built.
On the screenshot an interior offset can be seen. It looks exactly like the external shape (a face was generated and then extruded). The exterior offset has rounded corners.