Contextual Alternates in Arabic

hi all,
i’m new user and new at programming open type features, so how can i keep always the middle tooth in my font always high for beh, teh, theh, ex., like thing sketch done in illustrator! so please help.
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There is a tutorial about contextual Alternates that describes exactly the code you need.

In short, define two equivalent classes (same number and corresponding order of Glyphs) called teethDEF and teethHIGH, and put this code in calt:

sub @teethDEF @teethDEF' by @teethHIGH;

thanks mekkablue, this one you mean ?
https://glyphsapp.com/tutorials/features-part-2-contextual-substitutions

:slight_smile: i can’t understand yet where can i made those teethDEF, teethHIGH.
do you mean that i should create a new glyphs name teethDEF, teethHIGH?

No, new classes. Please read the tutorial, it is explained there.

thank you anyway, but i didn’t found any new tutorial or new classes.

What about this one?

The part titled ‘Cycling Through Glyph Classes’ explains how to set up classes. More detailed technical info can be found in the Handbook.

i’ll check and back to you.