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Chaining Context Substitutions

Posted: Fri May 13, 2016 10:32 am
by Bhikkhu Pesala
I guess this is a victory for the Visual OpenType Layout Feature Editor, as I don't really understand how to do this using code. What I wanted was for the lowercase r to be substituted with stylistic set 1 (ss01) after G and Y (and accented versions of these), but with stylistic set 2 after P and Q (and accented versions of these).

I created classes for PQ and GY (with the accented versions), and then added Contextual Alternates (calt) with chained context substitutions. The visual feedback on the Layout Feature Editor helped me to find a solution that worked by trial and error. I would not be surprised to learn that there's a better solution, but this does what I wanted without too much work.
Chaining Contexts.png
Chaining Contexts.png (104.34 KiB) Viewed 2223 times

Re: Chaining Context Substitutions

Posted: Fri May 13, 2016 11:22 am
by Erwin Denissen
And visually designing such features can be fun; especially when the expected results come alive!

Re: Chaining Context Substitutions

Posted: Fri May 13, 2016 12:20 pm
by Bhikkhu Pesala
The Comparison Toolbar helped me to decide which other Capitals to add to each class and the Preview Toolbar shows how the full alphabet looks, each glyph followed by the appropriate alternate lowercase r.
Preview Toolbar.png
Preview Toolbar.png (59.69 KiB) Viewed 2219 times

Re: Chaining Context Substitutions

Posted: Fri Jul 05, 2019 10:50 pm
by stormag
It might be worth mentioning, that Chaining Context Substitutions can be used for not only the Contextual Alternates (calt), but also for Required Contextual Alternates (rclt), when Chaining Context Substitutions are effectively the only "correct" way to go, assumed by the author of the font.