Re: [ft-devel] vertBearingY of CFF glyphs is always unscaled

[Werner LEMBERG]

[CCed Behdad]

> I had an issue with vertical text layout in HarfBuzz, in short we
> have the calculation:
> 
>       y = metrics.horiBearingY - (-metrics.vertBearingY)
> 
> and since horiBearingY is scaled with font size while vertBearingY
> is not, the result was completely wrong resulting in misplaced
> glyphs (it was "mysterious because it affected only glyphs where the
> value of this calculation was used, and the degree of misplacement
> changes with font size).

I fear that support for the various vertical metrics components is
severely broken in FreeType.  In particular, values are computed
differently for different font formats.  To fix this for all font
formats it would be necessary to investigate the issue in great
detail; in particular, we need a detailed comparison with the MS and
Apple engines: Some comments in FreeType indicate that, for example,
the OpenType specification and recommendations contradict the actual
implementation in Windows (and/or OS X).

Do you have some time to devote to this issue?  Or maybe another
volunteer?


    Werner