It is a Opentype question which is not related to Glyphs app. Do you know if it is possible to substitute for example two glyphs by three glyphs?
I have managed to change one by multiple or multiple by multiple as long as are equal numbers (for example three by three).
Two possible ways:
- Two separate substitution lookups: first a ligature,
a_b, then a one-to-many lookup,
a b c.
- A chaining contextual lookup, in which you call a lookup with one-to-many substitutions like
sub x y' lookup ONE2MANY;and the lookup
ONE2MANYis defined in the prefix and contains subs like
sub y by y z;.
Thanks! it’s not ideal but I will manage with the first option.
I can’t get this lookup to work:
sub A B C D by A B C E;
Always error message:
Make OTF error
Error: “Invalid ligature rule replacement” in Feature ccmp in line: 17
OpenType doesn’t allow this direct. There are ways to implement this but it requires several contextual substitutions.
sub A' B C D by a; sub a B' C D by b; sub a b C' D by c; sub a b c D' by d;
I didn’t try this and it might have some other side effects.
Thanks, could you please be more clear?
I guess you mean to break it down to 4 steps. What is the " ’ " for?
It indicates which character in the text stream will be replaced.
This is a contextual substitution. Read this please, it is explained here: https://glyphsapp.com/tutorials/features-part-2-contextual-substitutions
This was a great tip. Thanks.
I wish you all good health and better news…
This looks like the simplest way:
sub A B C D’ by E;
Do you see any issues with doing it like this?
sub A’ B C D E by a b c d e;
sub a b c d e B’ C’ D’ E’ by zeroWidthNoBreakSpace;
I’m searching for efficiencies in a large number of substitutions like this. This method seems to work well in testing.
That looks good.
Thank you all - this works perfect!