[HarfBuzz] font_get_h_extents & font_get_v_extents

[Khaled Hosny]

On Sun, Jun 26, 2016 at 11:11:11PM -0400, kelvinsthirteen at gmail.com wrote:
> 
> 
> > On Jun 26, 2016, at 10:25 PM, Khaled Hosny <khaledhosny at eglug.org> wrote:
> > 
> >> On Sun, Jun 26, 2016 at 10:05:15PM -0400, Kelvin Ma wrote:
> >> How do you get the plain ascent and descent of a font? font_get_h_extents()
> >> gives the HHead values of the font, not the regular ascent and descent.
> > 
> > There are three different settings for ascent and descent in OpenType
> > fonts, which one you are after?
> 
> The ones that partition the EM square. The ascent and descent should add up to the UPEM value.

I don’t know if there is such a thing, but it would be pretty useless
for many fonts as there should be no relation between EM size and
vertical metrics.