Concepts for a high level programming language for regional computer graphics

Researchers developing high-level graphics languages have, according to the literature, focused their attention towards line-drawing graphics. Little effort has been devoted to systematic investigations of languages that handle graphical data representing line-drawings as well as solid areas. The latter type of graphical data is usually represented hy outlines, and solid area properties are visualized by hatching or filling techniques. A study of the literature on programming languages leads to the conclusion that graphical data should be treated as a data type. Based on the concept of treating graphical data as a data type in its own right, the mathematical and conceptual aspects of this type of data are investigated and established. Much scattered information, such as the representation of regions, has been unified using formal descriptions. Hatching, one of the many ways of achieving external representation of regions, is also investigated. A hatching algorithm is proposed and implemented that envelops the good features of others, and establishes a framework for hatching algorithms. Its implementation achieves the expected tasks. A proposal for a graphics language demonstrates the usefulness and feasibility of this type of graphics. Some of its features have been implemented. Finally, a fairly complete bibliography serves as a gateway for further research in this area.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat