From: [email protected] [mailto:[email protected]] On Behalf Of Philippe Verdy
> Hmmm.... Given the current standard in OpenType, and the fact that > OpenType fonts cannot reorder glyphs to support the BiDi algorithm > and correctly handle featues like ligatures... I agree that OpenType font tables cannot to glyph re-ordering. But totally incorrect in saying that it cannot handle ligatures. > What this means is that, in practice, PUA are only usable in fonts for > characters with strong LTR directionality, excluding all reordering and > mirroring. In the OpenType specification, the only data related to glyph mirroring that a rendering engine is assumed to have is the bidi mirroring data from TUS 5.1. (See http://www.microsoft.com/typography/otspec/TTOCHAP1.htm#ltrrtl.) All other glyph mirroring is to be handled using glyph substitution data in OpenType Layout tables in fonts. Peter
