XPLG

摘要

An experiemtnal interactive graphics programming system has been built for a Xerox Sigma 5 computer based on William M. Newman's display procedures. The XPL compiler generator system was used for extending the syntax and semantics of the XPL language to produce a graphics language called XPLG. The XPLG compiler produces calls to a runtime support load module which handles windowing, viewports, clipping, boxing, 2-dimensional transformations, call naming, hit processing, etc. Independence from the numerous types of display and pointing devices is achieved by isolating all device dependent parts of the system in a separate, simple load module for each device. Several interesting implementation problems were solved.