Towards Object-Oriented Modelling of Euclidean Geometry
Maria Alberta Alberti, Eric Bastioli, Daniele Marini
This paper presents an object-oriented approach to interactive modelling
of geometric objects. The objects are specified by geometric constructions,
which are built mimicing the compass-and-ruler manual approach in a graphical
direct manipulation interface. The system adopts a "programming by example"
paradigm to incrementally enrich construction methods; new constructions can
be used to define new classes of objects or new methods for an existing class.
Messages exchanged among objects specify geometric relationships among entities.
Messages sent at construction time implicitly form a relationship network,
which is preserved during subsequent geometric transformations, allowing
to satisfy geometric constraints without recurring to numerical methods.
The prototype GEObject is implemented under Actor in Windows 3.0 environment.
gennaio 95, M.A.Alberti,
alberti@dsi.unimi.it