On Fri, Feb 12, 2010 at 07:21:14PM +0100, Hans Hagen wrote:
On 12-2-2010 19:03, Khaled Hosny wrote:
Is 'opbd' feature supported? According to the spec[1] this feature is used to define what I think is equivalent to the protrusion values used for optical alignment of the glyphs. I grepped the sources and there seem no be special handling of it, I don't have fonts that use this feature (I didn't look for one) but I'm planning to use it in my fonts and thought I'd check if ConTeXt support it first.
This Typophile thread[2] might be interesting too.
If fonts are needed I can check for free fonts that implement this, or prepare a font for testing.
[1] http://www.microsoft.com/typography/OTSPEC/features_ko.htm#opbd [2] http://typophile.com/node/48738
Indeed I need a test font in order to see how it can be implemented. If there are no fonts we should wonder what the exact spec is. Does fontforge support it?
I found that the font "fxlbi.otf" (of libertine fonts) has both 'lfbd' and 'rtbd' (left/right optical bounds) but no 'opbd' feature. Now re-reading the spec, I don't see what the values stored in 'opbd' is used for as the application has to consult 'lfbd' or 'rtbd' feature according to the position of the glyph in the line, I asked on OpenType mailing list but I don't expect getting an answer (nobody implemented this feature, except FontForge AFAIK.) My suggestion is to ignore 'opbd' completely and just use the values from 'lfbd'/'rtbd' directly. Regards, Khaled -- Khaled Hosny Arabic localiser and member of Arabeyes.org team Free font developer