GNU bug report logs - #33729
27.0.50; Partial glyphs not rendered for Gujarati with Harfbuzz enabled (renders fine using m17n)

Previous Next

Full log

Message #161 received at 33729 <at> debbugs.gnu.org (full text, mbox):

From: Khaled Hosny <dr.khaled.hosny <at> gmail.com>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: behdad <at> behdad.org, far.nasiri.m <at> gmail.com, 33729 <at> debbugs.gnu.org
Subject: Re: bug#33729: 27.0.50; Partial glyphs not rendered for Gujarati
 with Harfbuzz enabled (renders fine using m17n)
Date: Wed, 30 Jan 2019 00:33:30 +0200

On Sun, Jan 06, 2019 at 07:54:24PM +0200, Eli Zaretskii wrote:
> > Date: Sat, 5 Jan 2019 23:04:20 +0200
> > From: Khaled Hosny <dr.khaled.hosny <at> gmail.com>
> > Cc: far.nasiri.m <at> gmail.com, behdad <at> behdad.org, 33729 <at> debbugs.gnu.org
> > 
> > I pushed a couple of commits that does this based on my limited
> > understanding of Emacs code, please check.
> 
> Can you explain why you moved the call to
> hb_buffer_guess_segment_properties _after_ the code which sets some of
> the properties?  I cannot find anything about that in the HarfBuzz
> documentation.  Is this because guessing the unset properties can
> benefit from knowing the properties which _are_ set, such as the
> direction?

hb_buffer_guess_segment_properties() won’t guess set properties, so moving
it last was to avoid wasting time guessing properties that we will
override later anyway.

> I did it the other way around, because my mental model was: first set
> the defaults, then override them where better info is available.

hb_buffer_guess_segment_properties() is not for setting defaults (there
is no such thing as default buffer properties in HarfBuzz working
model), it is a kind of quick and dirty hack and production code should
not use it.

Regards,
Khaled

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.