[HarfBuzz] Shaping different scripts in the same text run

[Konstantin Ritt]

Or better look http://www.unicode.org/reports/tr24/#Common and
http://www.unicode.org/reports/tr24/#Nonspacing_Marks

Konstantin


2013/4/7 Khaled Hosny <khaledhosny at eglug.org>

> Please note that characters with common or inherited script property
> need special treatment, the corresponding Pango code is in
> pango/pango-script.c
>
> Regards,
> Khaled
>
> On Sun, Apr 07, 2013 at 02:07:15PM +0200, Lóránt Pintér wrote:
> > Thanks. I could manage to do this by using ucdn_get_script() for now.
> BiDi is going to be the next big challenge.
> >
> > --
> > Lóránt Pintér
> > Developer at Prezi (http://prezi.com)
> >
> >
> >
> > On Sunday, April 7, 2013 at 1:55 PM, Khaled Hosny wrote:
> >
> > > On Sun, Apr 07, 2013 at 02:59:32AM +0200, Lóránt Pintér wrote:
> > > > Hi,
> > > >
> > > > I'm struggling with the problem of shaping mixed text. Say I have
> Thai
> > > > and English text that I would like to shape. If I put all of it in a
> > > > buffer, HarfBuzz chooses a shaper based on the first identifiable
> > > > character, and then uses that shaper for the whole text. So
> > > > "<thai><english>" gets shaped fine with the Thai shaper, but
> > > > "<english><thai>" gets messed up because it is shaped with the
> default
> > > > shaper.
> > > >
> > > > I was trying to figure out how Pango does this, but found nothing
> yet.
> > > >
> > > > Is it possible to ask HarfBuzz to identify text runs inside a buffer
> > > > (or some other way) that can be shaped with different shapers? If
> > > > there was a call that would identify the script (and maybe writing
> > > > direction) of each character in the input, then I could split the
> > > > buffer at positions where these a different script is used.
> > > >
> > >
> > >
> > > You have to split the text runs before passing them to HarfBuzz, etch
> > > run should have the same script/language and text direction.
> > >
> > > Ideally text should be first itemized into runs with the same script,
> > > and further split them into directional run according to BiDi
> algorithm.
> > >
> > > There are of course more subtleties involved, like when using multiple
> > > fonts etc.
> > >
> > > Regards,
> > > Khaled
> > >
> > >
> >
> >
> _______________________________________________
> HarfBuzz mailing list
> HarfBuzz at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/harfbuzz
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/harfbuzz/attachments/20130407/48deb125/attachment.html>