3.4.1 Color hardcopy
When you produce a color picture (with plf or pli, for example) on your
screen, you need to save not only the picture, but also the palette you
used to draw that picture. Since the palette might change for each
frame in a hardcopy file, the file must contain a complete palette as a
sort of preamble to each frame. However, you usually want less
expensive, higher quality black and white output, so the palette
information is usually unnecessary. Yorick optionally converts colors
to a standard gray scale before output to a hardcopy file, saving a
little space in the output file.
If you are going to use a black and white printer, you can turn off
palette dumping by means of the dump= keyword:
(you could also specify the name for the next hardcopy file). Unlike
the name of the hardcopy file, the palette dumping flag persists across
any number of hardcopy files. To turn on dumping again, you need to
call hcp_file with dump=1.
All Yorick PostScript files will print on any PostScript printer, black
and white or color. However, if you set dump=0, the palette was
not dumped to the file, and it will print gray even on a color printer.
If you print a dump=1 file on a black and white printer, the
result will be very similar to dump=0; your colors will be
translated to grays. You can put the call to hcp_file setting
dump=0 in your `custom.i' file if you rarely want to dump the