Re: [groff] improve a few terminal renderings of special characters

[John Gardner]

> > I wonder if John Gardner's HTML-canvas renderer could lay down text
> > in a dark grey that's additive to what's already there, thus
> > over-striking would have an effect, e.g. `\z~o' as well as bold.

Does this not work already? Overstriking diacritics should work the same
for the renderer because it's processing the same movement and printing
commands Troff generates for post-processing...

> > Half-line motions would be nice too, John. ;-)
> > Heirloom's nroff still produces ASR-33 codes by default.

Don't worry, those are accommodated too
<https://github.com/Alhadis/Roff.js/blob/2ebfc4a2634001e5a849ac37f996e88481df4411/lib/postproc/text-grid.js#L646-L680>.
=)

On Thu, 23 Aug 2018 at 20:38, Ralph Corderoy <address@hidden> wrote:

> Hi Ingo,
>
> > > If there's expansions for U+2661 `white heart suit', or U+2665
> > > `black heart suit', etc., then they're `H'.
> ...
> > Besides, they do not have an ASCII representation, and i really
> > wouldn't see see the point in adding one, given that they don't even
> > have a groff character name - and it's good that they don't have a
> > name, IMHO.
>
> I agree more groff character names should not be added for these hearts,
> and that the two you pointed out that are `Unicode only' seem out of
> place in that documentation.
>
> But there's two things going on here.  Mapping `\(HE', etc., and mapping
> Unicode runes.  Unicode defines two sets of card suites, each
> distinguishing between red and black, e.g. here I see U+2661 as an
> outline heart versus the filled-in spade of U+2660.
>
>               +4  troff
>     U+2660 →♠  ♤  SP
>     U+2661  ♡ →♥  HE
>     U+2662  ♢ →♦  DI
>     U+2663 →♣  ♧  CL
>
> groff maps its four troff characters onto a mix of the two.
>
>     $ groff -Tutf8 <<<'\(SP\(HE\(DI\(CL' | tr -d \\n |
>     > iconv -t ucs-2le | od -An -tx2
>      2660 2665 2666 2663
>
> That's what the arrows are marking in the above list.  I'm guessing
> that's because they appeared all filled in originally, e.g. with
> Hierloom troff pulling in Adobe's Symbol font:
>
>     printf '\\C'\''%s'\''\n' spade heart diamond club |
>     ./troff -Tps | ./dpost >/tmp/cards.ps
>
> If the author specifies them by Unicode rune to get an above column of
> four then shouldn't `SHDC' appear as approximations for all four,
> regardless of column?
>
> > > An emoji heart would be `<heart>', but there doesn't seem to be a
> > > simple plain obvious heart emoji, but dozens.  :-)
> >
> > And those certainly do not deserve assignment of groff character
> > names, either.
>
> No, agreed.  So no typesetting of `I❤Unix' using Unicode then?
> That would be the place for your `<heart>'.
>
> > > I wonder if John Gardner's HTML-canvas renderer could lay down text
> > > in a dark grey that's additive to what's already there, thus
> > > over-striking would have an effect, e.g. `\z~o' as well as bold.
> > > For plus points, every glyph placed could have a slight random
> > > `jitter' applied to both its coordinates so bold was also thicker,
> > > except around the edges.  Half-line motions would be nice too, John.
> > > ;-)
> >
> > Right, and i want ponies.  And cute little unicorns!  ;-)
>
> I don't think PostScript's graphic model offers compositing two
> overlapping 0.7 greys to a saturated 1.0 black, but GhostScript's
> https://www.ghostscript.com/doc/9.23/Language.htm#Additional_operators
> borrows from PDF 1.4.  Heirloom's nroff still produces ASR-33 codes by
> default.  PostScript from them aiming at over-striking shouldn't be
> hard, and GhostScript could then produce PDF, PNGs, ...  :-)
>
> --
> Cheers, Ralph.
> https://plus.google.com/+RalphCorderoy
>
>