oSCUBA a buffered core graphic system
The graphics community is recently taking a close look at graphics standardization prompted by issues such as portability of software, application program structure, diverse hardware, etc. Through these efforts, the Graphic Standards Planning Committee of ACM/SIGGRAPH has proposed a standard. This standard advocates four levels of the Core system, namely basic, buffered, interactive and complete. This paper describes a Level 2 (i.e. buffered) implementation of the Core system in APL, referred to as oSCUBA (APL BUffered Core System). The details of the structure and organization of oSCUBA are given. The implementation is highly modular in nature, provides both two and three dimensional capabilities with several types of projective transformations and supports full segmentation capabilities. Several examples illustrating the use of the system are included. The interactive nature of APL is found to be attractive. Some deviations from the Core system have been incorporated. These include a modular hardcopy interface to produce graphics on plotters etc. and a facility to retain world coordinates of the objects. The system, though appearing to be satisfactory, has to undergo further testing to gain user confidence.