Advanced Concepts for High - Level Graphics Languages

Much effort has been expended in the past years on the specification of the CORE and the GKS subprogram system standard proposals. Both have a common intent: They standardize the input/output interface between an application program and the graphics terminals. Such systems can not, however, address the modelling problem, i.e. ways and means to create or define graphical objects. This task is at present still left to the application program. As the demand for increasingly sophisticated graphical output rises, more effective software tools must be developed. It is the purpose of this paper to demonstrate the capability and effectiveness of a high-level graphics programming language for modelling. In particular, high-level operations required for modelling, such as the explicit definition as well as functional generation of graphical objects, and the systematic manipulation, editing, and substitution of graphical data are discussed. Several explicit examples of modelling of graphical objects with the aid of essential program fragments and their resulting output are presented, by this means simultaneously high-lighting some of the characteristics of the Language for Interactive Graphics (LIG6).