Re: [Groff] pic and nroff

[Tadziu Hoffmann]

>   1. Set pic's `arrowhead' style variable to 0 so that
>      arrowheads aren't filled.  It's probably worth to handle
>      this with a new command line option for `pic', similar to
>      option -n (which does more than that).
> 
>   3. Say `.color 0' before and `.color 1' after the image.
>      [This is the first time I see a useful application of
>      this request which I've introduced a long time ago :-)]

Both of these don't concern groff code, so, regardless of what
else is done, they will remain options available to the user.


>   2. Undo an optimization within pic which currently assumes
>      that fill and glyph colours are completely independent.
>      This would mean that after a filled object the fill
>      colour is immediately reset to the default.

This sounds like a reasonable solution (least likely to give
surprising results).

[In which way are fill and glyph colors not independent?]


> The fix is not easy, unfortunately.  Arrow heads are always
> filled with the outline colour, which is black.  `pic' thus
> has to change the fill colour accordingly.  I can't imagine
> any way to make that work automatically work with TTYs.

Maybe a solution would be to introduce a "background color"
independent of glyph (=foreground) and fill color, for those
devices that support it (such as grotty).  Although grotty
would still use a "color background" (in the character-cell
device output) for filling graphics objects, background colors
could (additionally) be used independent of this.

Whether grotty should honor background colors (e.g., for
screen output) or ignore them (e.g., for lineprinters)
could be controlled with a new keyword in the DESC file.