At present, object-oriented programming is emerging from the research
labora- tories and invading into the field of industrial applications.
More and more products have been implemented with the aid of
object-oriented programming techniques and tools, usually as extensions
of traditional languages in hybrid development systems. Some of the
better known examples are OSF-Motif, News, Objective-C on the NeXT
computer, the C extension C++, and CLOS an object- oriented extension of
LISP. All of these developments incorporate interactive graphics.
Effective object-oriented systems in combination with a graphics kernel-
does it mean that the field of computer graphics has now become merely
an aspect of the object-oriented world? We do not think so. In spite of
interesting individual developments, there are still no sound
object-oriented graphics sys- tems available. If it is desired to
develop a complex graphics application embed- ded in a window-oriented
system then it is still necessary to work with elemen- tary tools. What
is to be displayed and interactively modified inside a window must be
specified with a set of graphics primitives at a low level, or has to be
written with a standardized graphics kernel system such as GKS or PHIGS,
i. e., by kernels specified and implemented in a non-object-oriented
style. With the terms GKS and PHIGS we enter the world of international
graphics standards. GKS and PHIGS constitute systems, not mere
collections of graphics primitives.