An object-oriented kernel for geographical information systems

The development of a graphical kernel for geographical information systems is reported. It is based on a multi-dimensional data structure called GBD tree which provides an efficient environment for spatial data retrieval. Graphic entities are classified and represented by a small set of primitive geometrical entities which are implemented as a C++ class library. Applications can derive their own data types from the providing kernel by exploiting the IFO object-oriented data model. Although the main purpose is to support the GIS applications, it can be expected that this graphic kernel can be extended to a general-purpose one for graphic applications