[ft-devel] Glyph with in OTF fonts

[Behdad Esfahbod]

Hi,

CFF encodes glyph advance widths.  OpenType CFF fonts as such encode glyph
advance widths in two places: the hmtx table, and the 'CFF ' table.

Previous versions of the OpenType specification required that the advance
widths specified in the two tables be equal.  This was changed in the newly
released OpenType 1.7:

  http://www.microsoft.com/typography/otspec/hmtx.htm

the idea is that fixed-width and proportional-width versions of a CJK font
should be able to share the CFF table and have different hmtx tables.

In my testing in August 2013, FreeType uses the advance widths from CFF table,
not hmtx.  I'm not sure if this was with new or old CFF rasterizer.  At any
rate, both should be switched to use the hmtx metrics instead.  That is, just
use the TrueType code for CFF.

Cheers,

-- 
behdad
http://behdad.org/