Re: [NTG-context] Making necessary OpenType features on by default

On Sat, Feb 21, 2009 at 12:41:48PM +0100, Hans Hagen wrote:

Idris Samawi Hamid ادريس سماوي حامد wrote:

...

On Fri, 20 Feb 2009 11:39:23 -0700, Khaled Hosny wrote:

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Microsoft's OpenType features list page (http://www.microsoft.com/typography/otspec/features_ae.htm) gives a "UI suggestion" for each feature noting if it should be on by default,

Hmm, I think this page is more relevant for what you have in mine:

http://www.microsoft.com/typography/otfntdev/arabicot/features.htm

:-)

watch the "The standard order for applying Arabic features encoded in OpenType fonts" ... an earlier mkiv otf handler did this but then we found out that it violates the otf 'any order possible' rule so now we do just the order as we encounter it (and even then it took us a while to figure out where/how to avoid interferences); so ... it's up to the font designer (or technician)

IIRC, the 'ccmp' should be applied before any other lookup, the rest are applied as they are ordered in the font, at least this makes sense more.

now, having init, medi, fina, isol, rlig enabled might be the default, but for instance arabtype output looks much better when instead of rlig we use calt/clig etc so, in that case the defaults would bot be the best choice; again an argument for a database approach

Arabic Typesetting is a quit a special case font, though I believe that 'calt' and 'clig' should be on by default for any font.

there are even fonts out there that have the right gsub/gpos info but lack the feature being listed in the script/lang dictionary which is complicating live even more; maybe we should assume that the renderers of ms and adobe have some additional built in heuristics of using specific fonts

Any links to such fonts? Looks interesting. Regards, Khaled -- Khaled Hosny Arabic localizer and member of Arabeyes.org team