This document will show you how to write programs using the Object Oriented Graphics Library (OOGL). It will also give you an introduction to using geomview—a 3-dimensional viewing program written using OOGL. By using geomview, your application is freed from having to do any specific graphics functions. 1
The OOGL routines are a high-level set of modules that let you specify and display geometry. There are several types of geometric primitives which OOGL can handle, including polygons, vectors, meshes, and parametric surfaces patches. In addition, these primitives can be organized into a higher-order lists. Also, multiple instances of the same geometry can be created by specifying different modeling transformations. Each sort of geometric object, whether low-level or high-level, comes equipped with a standard set of operations. Examples of these operations include loading from and saving to files, drawing to a display device, and computing a bounding box. This style of programming, which combines data structures with operations which act on these data structures, is known as object-oriented programming. Although currently OOGL only works on SGI workstations, it has been designed to make it easy to port to other environments.
It is assumed you know how to program in C. After reading this and looking through the example programs you will be ready to create your own OOGL applications.