The 'background' csh script changes the screen background color/image via pft

Usage background -reset
      background -gray GrayShade
      background -RGB Red Green Blue
      background -{file, center, scale, minscale, tile, debug} FileName

0.0 <= GrayShade, Red, Green, Blue <= 1.0
FileName = Encapsulated PostScript file.

Options can be shortened to just their first letter, eg. 'background -g 0.666'
The 'gray' & 'RGB' options can be combined with 'file', 'center' and 'minscale'

The 'file' option just puts up an image at {0,0}, the 'center' option centers
the image on the screen instead.  The 'scale' and 'minscale' fit the image to
the screen -- 'scale' maintains aspect ratio, 'minscale' doesn't.  The 'tile'
option tiles the screen with an image.  Only one of these options should be
used at a time.

Modified by Gilles Detillieux (gilles@scrc.UManitoba.CA) Jan 9-11/91:
- fix BoundingBox handling to allow negative origin, handle missing space
- add "0 setgray" before file copied
- add -debug option to see generated code
- change window handling so it works under 2.0

Updated Aug 25/93 - cdl
- rewrote window handling so it works under 3.1
  (awful hack might even be backward compatible)

Modified 4/18/94 - cdl
- incorporated a setrgbcolor option ala Darcy Brockbank's USENET post
- fixed bug in debug case statement

- Christopher Lane (lane@camis.stanford.edu) 4/18/94

Copyright '90, '91, '92 '93 & '94 by The Leland Stanford Junior University.
This program may be distributed without restriction for non-commercial use.
