The GTVIRT is a fast low-level Graphic library, allowing to develop Graphic programs in a completely device independent way. The GTVIRT library involves the following concepts:
Each directory has its own User coordinate system. This feature can be used to map several coordinate systems to different or similar regions of the Plot Page.
The GTVIRT normally operates in a buffered mode. All drawings command a written into an internal metacode, and only transmitted to the plotting device when required by the calling program. In addition, for applications which require an unbuffered plot, an immediate mode is available.