[OpenType] RE: Proposal: deprecate ReqFeatureIndex

[Behdad Esfahbod]

On 08/21/2012 07:10 PM, John Hudson wrote:

> I proposed <rclt> because I and other designers are producing type 
> designs that rely for intended display on contextual substitutions, and 
> that may be anything from less-than-beautiful to actually unreadable if 
> these substitutions are turned off. In some respects, I think the 
> OpenType assumptions of script required, language exception, and 
> typographic optional layout are misleading, because the category of 
> design required features does not fit neatly onto the structure. This is 
> the category where we're increasingly working.

Fair enough.

> And I agree with you that the ReqFeatureIndex is just daffy.

IMO you are contradicting yourself, as ReqFeatureIndex does *exactly* what you
are asking for.  Ie, a feature that can't be turned off!

Lets be clear: the situation right now is that ReqFeatureIndex is not
universally implemented, mostly because Adobe didn't implement it in some of
their products.  And because of that, it's unreliable, and as a result Adobe
is requesting that it be deprecated.  Oh well...

Let me also respond to Sairus's statement that OT spec does not specify when
to apply the required features.  I don't think it's a valid point, because the
spec does NOT specify those kind of things for any feature...  All of us know,
the details of how to use the data in the font have always been unwritten.

My 0.02CAD,
behdad