larry@JPL-VLSI.ARPA.UUCP (12/06/86)
How does X relate to the ANSI and soon-to-be ISO Graphical Kernel
Standard? Do they serve the same or similar purposes? If so, why
this needless duplication? Or is there some good reason for it?
Larry @ jpl-vlsigarry@TCGOULD.TN.CORNELL.EDU.UUCP (12/10/86)
In a recent article larry@JPL-VLSI.ARPA wrote: >How does X relate to the ANSI and soon-to-be ISO Graphical Kernel >Standard? Do they serve the same or similar purposes? If so, why >this needless duplication? Or is there some good reason for it? X is a "windowing system" while GKS is a "graphics package". Technically, the distinction is mostly a matter of emphasis - a graphics package will as a rule go on at great lengths about geometry, renditions, and transformations, and only touch moderately upon text and screen windows, A windowing system, on the other hand, will concentrate on doing text and updates speedily, and keeping the screen windows organized, and only touch upon geometry and transformations. Graphics packages generally allow some form of "stored display list" - but do not allow sharing of the screen - while windowing systems generally allow (encourage) multiprocessing on a single screen but run in "immediate mode". Both kinds of system are can be either programmed or utility-driven. As a rule of thumb, if you have both, you'll use standard utilities to drive the windowing system (one of the commonest window system utilities is the terminal emulator) and you'll write programs to drive the graphics system. None of the above distinctions are absolute - both kinds of system have the same purpose of displaying information to a user on a graphics screen. They just differ in particulars between what's made easy to do and what's made hard/impossible. There are numerous books in the bookstore on GKS and other graphics packages; I'm not aware of any books on X yet, but for a related windowing system you might try the "Smalltalk 80" book. Hope this helps. Software, at this level, is *not* simple. Rumors to the contrary are unfounded. :-) garry wiegand (garry%cadif-oak@cu-arpa.cs.cornell.edu)
gwu@VLSI.CS.CMU.EDU.UUCP (12/10/86)
At least here in the ECE Dept. of C-MU, we try to write all of
our graphics software in GKS. We have a GKS implementation for the X
Window System, and a GKS implementation for several other
machines/devices which do not run X. These include our Imagen Laser
printers, our HP pen plotter, C-MU's Andrew system, and HP9836s and
HP9000/300 running HP-UX. This way, our stuff works on machines which
run X, but also work for other devices and machines.
George J Wu