From: Eli Zaretskii <eliz@gnu.org>
To: James Cloos <cloos@jhcloos.com>
Cc: 39554@debbugs.gnu.org
Subject: bug#39554: 27.0.50; cairo not composing sequences
Date: Wed, 12 Feb 2020 21:59:37 +0200 [thread overview]
Message-ID: <83lfp7r2za.fsf@gnu.org> (raw)
In-Reply-To: <m3d0ajd4fq.fsf@carbon.jhcloos.org> (message from James Cloos on Wed, 12 Feb 2020 13:51:53 -0500)
[Please keep the bug number on the CC list.]
> From: James Cloos <cloos@jhcloos.com>
> Date: Wed, 12 Feb 2020 13:51:53 -0500
>
> >>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:
>
> >> Sequences like 0̸ fail to display composed in master --with-cairo but do
> >> when usin xft.
>
> EZ> Please show a complete reproducing recipe for this problem.
>
> The 0̸ in thequoted line is one.
Sorry, I failed to realize that ̸ was a combining accent, not an ASCII
slash.
In an Emacs built with HarfBuzz on MS-Windows, if I use a font that
has support for ̸, I do see these two characters composed into a single
glyph whose width is as that of a single character. But if I use
DejaVu Sans Mono, I indeed see a double-width grapheme cluster. So I
think this might be related to font selection somehow. Can you try
different monospaced fonts and see if the results in the Cairo build
are better with other fonts?
> EZ> This means that the font backend couldn't produce a single glyph for
> EZ> the character combination, for some reason, so it displayed the
> EZ> original glyphs as a single grapheme cluster. IOW, character
> EZ> composition did work, it just didn't find a precomposed glyph in the
> EZ> font, or maybe the precomposed glyph was rejected for some reason.
>
> It is not supposed to be looking for precomposed glyphs. It is supposed
> to be rendering each combining glyph on top of the base glyph. Just
> like xft does.
The way character composition works in Emacs, we first ask the font
for precomposed glyphs, and display them if the font has them. If
that fails, then we combine the separate glyphs ourselves. See
compose-gstring-for-graphic.
next prev parent reply other threads:[~2020-02-12 19:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-10 20:53 bug#39554: 27.0.50; cairo not composing sequences James Cloos
2020-02-11 3:26 ` Eli Zaretskii
[not found] ` <m3d0ajd4fq.fsf@carbon.jhcloos.org>
2020-02-12 19:59 ` Eli Zaretskii [this message]
2020-02-13 20:16 ` James Cloos
2020-02-13 20:24 ` Eli Zaretskii
2020-02-14 0:58 ` James Cloos
2020-02-14 1:07 ` YAMAMOTO Mitsuharu
2020-02-14 4:50 ` James Cloos
2020-02-14 8:44 ` Robert Pluim
2022-02-10 7:25 ` Lars Ingebrigtsen
2022-02-11 20:40 ` James Cloos
2022-02-12 6:50 ` Eli Zaretskii
2022-02-11 20:48 ` James Cloos
2020-02-11 3:27 ` Eli Zaretskii
2020-02-12 18:54 ` James Cloos
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=83lfp7r2za.fsf@gnu.org \
--to=eliz@gnu.org \
--cc=39554@debbugs.gnu.org \
--cc=cloos@jhcloos.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).