[HarfBuzz] What is the utility of the advances list?

[Jonathan Kew]

On 29/10/13 10:19, eduardo wrote:
> Hi,
>
> Why does hb return a list of advances when, given a glyph, it can easily
> be extracted from the font? Are the glyph advances context dependant? If
> so, what is a good language/script to see the difference?
>

Yes, of course they're context-dependent. The simplest example may be 
kerning. If the GPOS table contains a kern pair for "AV", then the 
advances you get from harfbuzz for the 'A' and 'V' glyphs will not be 
the same as the individual glyph advances you'd find in the font.