bug#72268: 31.0.50; Color emoji rendering

[Manuel Giraud via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Manuel Giraud <manuel@ledu-giraud.fr>
>> Cc: Po Lu <luangruo@yahoo.com>,  72268@debbugs.gnu.org
>> Date: Wed, 24 Jul 2024 13:59:10 +0200
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> >> Date: Wed, 24 Jul 2024 10:59:03 +0200
>> >> From:  Manuel Giraud via "Bug reports for GNU Emacs,
>> >>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> >> 
>> >> With emacs configured as below, I have a weird rendering for color
>> >> emojis:
>> >
>> > I don't think we support color Emoji without Cairo.  Po Lu, am I
>> > right?
>> >
>> > If you use a black-and-white Emoji font, do Emoji display correctly?
>> 
>> Yes they do.  The black and white "Noto Emoji" are correctly displayed.
>
> I think this is all you can expect without Cairo.
>
>> FWIW, a Cairo build is worse in this regard: no Emoji are displayed at
>> all (black and white or color).
>
> That's strange, because AFAIK users on GNU/Linux do report very good
> results with Cairo and color Emoji fonts.  Did you try Noto Color
> Emoji (which is the default font for Emoji in Emacs)?

Yes.  I think that I'd better try to resolve this issue (w/ a Cairo
build) than try to solve it in Xft.

Currently, with a Cairo build, Emoji are displayed with empty boxes (not
the boxed hex representation, just empty ones).  'C-u C-x =' says it is
"Noto Color Emoji".  I'm using cairo 1.18.0.
-- 
Manuel Giraud