Re: [Groff] strange commands in grn

[Daniel Senderowicz]

>From an old gremlin tutorial, page 19 (Dec 29, 1984):

... start quote {

6.1. Stipple Filled Polygons
   The introduction of stipple filled polygons has meant a few
changes to GRN. If your picture includes polygons, you should
specify the stipple type (UNIGRAFIX or CIFPLOT) to GRN as
follows:
                     st cf
or,
                     st ug
The default stipple patterns displayed in GREMLIN are CIFPLOT
stipples. In addition to choosing the stipple type, you can also
select stipple patterns other than those displayed by GREMLIN.
Each picture may contain up to eight different stipple patterns.
You can make the association between stipple pattern number (1 -
8) and the stipple pattern using the commands (l1, l2, ..., l8).
The stipple pattern is denoted by its index in stipple font file
(see Appendix B). Note that there are 32 CIFPLOT stipple patterns
and 64 UNIGRAFIX stipple patterns. The default associations,
which you need not specify, are as follows:

                     l1 1
                     l2 3
                     l3 12
                     l4 14
                     l5 16
                     l6 19
                     l7 21
                     l8 23

It is also possible to make these same associations when you run
GREMLIN so that the stipple patterns displayed in the editor are
the same as those printed. See section 9.

} end quote

With respect to .sc I can't remember but I have it in my header
file for all my roff texts (probably since the epoch), but if I
find it I'll post it.

Dan

>Who knows what the commands .sc and .st are?  I couldn't find any
>reference.  They are used in the grn source code to select a stipple
>apparently...