[ferret_users] "reverse video" PostScript

[Ryo Furue <furue@xxxxxxxxxx>]

Hello all,

Perhaps this has been discussed, but since I didn't find
an answer in the mailing-list archive, I summarize what
I did to get a "reverse video" PostScript output.

Goal: to draw axes and labels in white in the PostScript
      output.

A solution:

   yes? ppl color 1 99 99 100  !! not exactly "white"
   yes? ppl color 2  0  0   1  !! not exactly "black"
   yes? set mode metafile
   yes? fill/i=1:10/j=1:10 i+j
   yes? contour/i=1:10/j=1:10/color=2/ov i+j  !! black contours
   yes? quit
   $ gksm2ps -R -o myplot.ps -l cps metafile.plt

This works with

        FERRET v5.70
        Linux(g77) 2.4.18 - 06/30/04

The trick is

   ppl color 1 99 99 100  !! not exactly white
   ppl color 2  0  0   1  !! not exactly black

It seems that if you use the exact white "100 100 100", then color 1
is regarded as "the foreground color" and drawn in black by PostScript
renderers (like ghostview).  The same applies to black, I think.

The reason I want this is that I use a very dark background for
my PowerPoint presentations and I want the imported plots to have
white axes and labels with a transparent background.

Hope this is of some help to somebody,

Ryo