On Mon, Jun 28, 2010 at 03:47:40PM +0000, Murray Sargent wrote: > Khaled notes: "There are so many issues with MS implementation(s), for > example you can not combine any arbitrary Arabic diacritical marks on any > given base character. I don't think Unicode need to invent workaround broken > vendor implementations, interested parties should instead pressure on that > vendor to fix its implementation(s)." > > The MS Office math facility allows combining marks in the range > U+0300..U+036F and most in the range U+20D0..U+20F0 to be applied to any base > character(s) including complicated mathematical expressions. Such generality > is needed in mathematics, since tildes, hats, bars, etc., are displayed over > multiple base characters such as the expression a+b. Hebrew and Arabic > combining marks aren't currently treated as valid mathematical combining > marks, so the sequence U+25CC U+05BC U+05B8 doesn't render as Vincent desires > in a math zone. It seems reasonable to allow all Unicode combining marks as > accents in math zones.
That would be nice, but we were talking about combining marks in normal, non-math, text. For example, it is now common practice to use two consecutive Fatha/Damma/Kasra for a certain form of Arabic tanwin used in Koran, however Uniscribe won't allow this and will always insert a dotted circle between the two marks. I know this behaviour is documented, but I fail to see the rationale behind it. Generally speaking, doing "script spell checking" in the rendering engine is a lousy idea IMO. Regards, Khaled -- Khaled Hosny Arabic localiser and member of Arabeyes.org team Free font developer
