How to create a contextual substitution

FontCreator - Font Editor FontCreator - Support
1

I need to create a feature that sometimes substitutes an alternate glyph depending on what precedes it. For example, if a certain class of glyphs are preceded by a certain class of other glyphs, they should be replaced by alternate glyphs with small changes.

Here’s what I have, below. “Backtrack” and “Input” make sense to me, and I’ve created glyph classes for those. But I don’t understand “Substitution table.” How do I create the correct one-to-one substitution table? I can create a table, but I don’t know how to edit it.
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1 Like
2

You need to create a dangling substitution lookup and then add that as Substitution Table.

3

Ok, I created a substitution table. But I am not getting the substitutions, and it says “not used.” What am I missing? Thanks.
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4

Sorry to bump this, but I am still stuck. What am I missing here?

5

FontCreator just didn’t update the info, so it kept showing “not used”. The next upcoming update will fix it.

6

Thanks, but just to clarify, I’m using PC at the moment, since Mac crashes when I add a lookup.

Is single substitution currently not possible on PC?

7

Of course it is possible, but in your case the contextual lookup (SUB Mark BLW) is not added to a feature, so it is unused.

We have just released a new Mac version, 15.0.0.3003. Do give that one a try!