The Computer Graphics Virtual Device Interface

Decisions about which functions to include in systems like PHIGS and GKS-3D are based primarily on the tasks users want performed, such as direct support for 3D operations. The design criteria for device interface systems like the Computer Graphics Virtual Device Interface, however, must be based on what is feasible to do in a device, while still considering how to decompose tasks into hardware-realizable functions. Complicating these design decisions is the wide range of existing device technology and the breadth of usage models imposed by different task-oriented software.