Re: Small caps problem/bug with some fonts

[Hans Hagen <pragma@wxs.nl>]

Barry Schwartz wrote:

> The font is unambiguous about it, though. Are you sure the software
> isn't performing the feature list in order rather than lookup list? Or
> is the software performing substitutions in its own ad hoc order?

in basemode we use built in traditional tex methods, so only ligatures 
and kerning; as a bonus i also support replacements, but in base mode 
the user really has to know what he/she asks for; in thsi particular 
case, asking for both ligatures (not contextual btw) and repacements 
(smsc) one gets them combined

so, this is why there is (the somewhat slower but more conforming) node 
mode as well; in that case (contextual) lookups are taken care of

but even then, if a font is not clear about issues, then one can get 
unwanted side effects (the frac feature for instance is often quite 
bugged and can only be applied selectively)

also, in context mkiv we have variants like dynamic features, user 
defined features, strategies etc (after all, nothing can stop us from 
doing a better job)

> Now I _make_ opentype fonts with small caps and ligatures and so want
> the software to do what I tell it (except when it was I who made the
> error).  :)

well, as said ... base mode has some known limitations and if you want 
the whole lot, you should use node mode (fyi: apart from isolated 
features we also support mixtures; the open type font format makes no 
assumptions about tags and gpos/gsub application so for instance the 
smallcaps feature might use one-to-one subsititutions as well as any 
other kind and complex fonts (like idris arabic font) does that)

(maybe simplefonts should default to node mode)

Hans

ps. if you run (as i demonstrated at the eurotex/context conference)

mtxrun --script server --auto

you can access an interactive features tester in your webbrouwser

there is also a trace option there where you can see what happens (in 
node mode)

Hans

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