Re: [ft] FreeType Metrics Question

[Grzegorz Rolek]

There's no explicit metric for the cap height in a font file. There indeed 
might be such a metric in font editors, but only as a guide for the designer. I 
doubt any rendering engine calculates the cap height from the font because that 
would mean making a lot of assumptions. I actually don't think the value is of 
any use at this level since the process of spacing the line requires only one 
height from the baseline up to set it properly and the ascender value provides 
this already.

If you indeed need a consistent line spacing between different platforms, then 
you probably want to look into the line gap value, i.e. extra whitespace set 
for a particular font, which has redundant entries in the font, each of which 
being used differently by different platforms. For brief explanation of the 
problem see the section on linespacing, page 23, at Dr. Jürgen Willrodt's 
presentation on OpenType spec at 
http://fonttools.org/downloads/TD_2009/OpenType_Status_2009.pdf.


On Aug 4, 2012, at 6:21 PM, Andreas Sandberg wrote:

> I think actually what I need is the ability to retrieve the cap height.  Is 
> something thats possible to retrieve?

On Aug 6, 2012, at 8:35 PM, Andreas Sandberg wrote:

> So, I just need a way to retrieve the cap height from a font if that's 
> possible.  From some of the font editors I've briefly played with, it does 
> seem possible but I cant' find reference to it in the freetype api.