[HarfBuzz] How to increase harfbuzz numerical precision

[Khaled Hosny]

It is, but you have to set it separately, and then you can set the font
scale to whatever value you need without both being interdependent.

On Tue, Jun 28, 2016 at 07:15:23PM -0400, Kelvin Ma wrote:
> I thought ppem was dependent on UPEM and font scale, is it not?
> 
> On Tue, Jun 28, 2016 at 7:12 PM, Khaled Hosny <khaledhosny at eglug.org> wrote:
> 
> > Device tables depend on ppem, so despite the scale being set
> > on the font, you should still set the exact ppem.
> >
> > On Tue, Jun 28, 2016 at 06:43:58PM -0400, Kelvin Ma wrote:
> > > so that’s the only way huh…
> > > doesn’t that kind of defeat the purpose of hb.font_create() and having
> > many
> > > scaled versions of the same font? You would only ever need one font of
> > each
> > > face, scaled to the UPEM, if the fontsize was to be applied externally
> > > after shaping already occurred.
> > >
> > > On Tue, Jun 28, 2016 at 5:51 PM, Behdad Esfahbod <behdad at behdad.org>
> > wrote:
> > >
> > > > HarfBuzz coordinates work in a int32 space.  You are free to set
> > whatever
> > > > scales you want on the font.  For example, use 6 or 8 or 10 or 16 bits
> > of
> > > > sub-pixel precision by multiplying your scale by a number.
> > > >
> > > > On Tue, Jun 28, 2016 at 4:57 PM, Kelvin Ma <kelvinsthirteen at gmail.com>
> > > > wrote:
> > > >
> > > >> It appears that harfbuzz rounds all decimals to integers when giving
> > > >> glyph advances and offsets. This is causing some ugly misalignment
> > problems
> > > >> in arabic shaping, as well as latin cursive fonts. (see pictures)
> > > >>
> > > >> [image: Inline image 1]
> > > >>
> > > >> [image: Inline image 2]
> > > >>
> > > >> [image: Inline image 3]
> > > >> How do I get harfbuzz to preserve the floats?
> > > >>
> > > >> _______________________________________________
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> > > >> HarfBuzz at lists.freedesktop.org
> > > >> https://lists.freedesktop.org/mailman/listinfo/harfbuzz
> > > >>
> > > >>
> > > >
> > > >
> > > > --
> > > > behdad
> > > > http://behdad.org/
> > > >
> >
> >
> >
> >
> >
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> > > https://lists.freedesktop.org/mailman/listinfo/harfbuzz
> >
> >