.calt code model?

Andreas Stötzner

Sorry for my ignorance …
I just fail to find a suitable reference for the following issue:
The font features some peculiar descender shapes which collide with other letters in some instances. I’d like to solve this by the .calt feature. It’s only a few pairings, nothing really tricky I suppose. But I just miss to catch the suitable code model snippet … single glyph approach preferred over class definitions, probably.
– Any advise highly appreciated!

Mike Wenzloff

Here's one such available location on the web that is pretty easy to understand and apply.

https://glyphsapp.com/tutorials/features-part-2-contextual-substitutions

Mike

Andreas Stötzner

thanks Mike, this is what I have been looking for.

Igor Petrovic

I have a situation where the class appears often in calt substitutions, but here and there some other letters appear in addition to that class as subjects of substitution.

So I would like to check would this code work:

sub [@class a b c] [j jcircumflex]' by [j.alt jcircumflex.alt];

In other words, can @class definition be part of [ ] class definition?

Florian Pircher

Yes. Have a look at the feature file specification for details, in particular section 2.g.ii:

http://adobe-type-tools.github.io/afdko/OpenTypeFeatureFileSpecification.html#2.g.ii

Igor Petrovic

Thanks!