11.12. What makes up Display PostScript?
Display PostScript has many different features, a few of
which are:
- Extensions to the PostScript language
- Multiple execution contexts: where multiple different
PostScript programs can be run independently and simultaneously
(needed for window environments);
- User name encodings : These allow for improved efficiency;
- Support for windowing systems : Extensions to PostScript
that allow display specific information;
- Bitmap font coordination : These allow for improved
legibility of text in a window.
- A PostScript Interpreter
The enhanced PostScript Interpreter has the ability to interpret
standard PostScript commands, as well as the extensions provided
with Display PostScript.
- A C language interface (the Client Library)
to Display PostScript's facilities. The client library is an
interface into Display PostScript which enable it to be used in C
programs. It is a translator, so that when the C program is
compiled, it knows what to do with Display PostScript parts.
- Support libraries for different windowing systems
As different Window managers handle scrolling, redrawing,
resizing, cursor functions, etc., in different manners, Display
PostScript has methods for determining the characteristics of
each window system and then works with it to provide graphical
display and interaction.
- pswrap, a preprocessor that enables a PostScript
program to be wrapped in a C program. This is a package that
enables C to send PostScript code to a PostScript interpreter.
This means that it calls the PostScript program, keeping it in
its native state, rather than using a binary format of it as in
the Client Library.
