bug#62994: [PATCH v7] Add support for colored and styled underlines on tty frames

[Jim Porter]

On 4/21/2024 11:01 PM, Eli Zaretskii wrote:
> > Cc: 62994@debbugs.gnu.org
> > Date: Mon, 22 Apr 2024 08:44:15 +0800
> > From:  Po Lu via "Bug reports for GNU Emacs,
> >   the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> >
> > This change should be accompanied by like updates to *_draw_glyph_string
> > and related functions in the remaining terminal backends.
>
> I believe Jim Porter wanted to work on that.  Jim, have you made any
> progress in this matter?

I spent some time looking at it, and I have what I think would be a 
reasonable path forward. Essentially, make a more-generalized form of 
'x_draw_underwave' that can draw a tiled 1-bit image for the underline, 
and then pass the image data in as an argument. That would keep the code 
duplication to a minimum.

I haven't gotten a working implementation of this idea yet though, since 
I've been very busy with non-Emacs things. If someone else is itching to 
work on this, go for it. Otherwise, I should have a lot more free time 
by May.