Re: [ft-devel] [GSoC] Extending the CF2 interpreter

[Hin-Tak Leung]

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On Mon, 17/7/17, Werner LEMBERG <address@hidden> wrote:
 
> Looks like a buglet (or feature) in
> FontForge.  It seems that the
> ascender and
> descender values are based on the font's bboxes of
> all
> glyphs (taking probably the maximum and
> minimum, respectively).
> However, the OS/2
> values should be taken literally instead.

I'd say it is probably a feature of FontForge rather than a bug, to actually 
sum all the bound boxes. OTOH, surely global ascender /descender is not related 
to line-spacing at all? It is entirely conceivable, though extremely unlikely, 
that a font is, by design, having a lot of hanging-below and sticking-above 
bits, or having very line-spacings within nothing much between.

I think the Zapfino font ( https://en.wikipedia.org/wiki/Zapfino ) is a good 
illustration of the "lots of hanging-below and sticking-above bits" idea...