Arabic font : "Mark" problem with Ligatures.

ahmederaqi

hello,
I'm creating an Arabic font but i got a problem that when i type "Lam" and put mark "tashkeel" on it and "Alef" after that I found that the ligature doesn't work . but without the "mark" the ligature works fine.

John Hudson

You need to set the process marks flag in the ligature lookup to not process any marks, then the substitution will ignore the presence of any marks.

Another method would be to not treat the lam+alif as a ligature glyph, but instead as contextual variants, which would be particularly easy with the shape you are using. To do this, you would cut your ligature into two pieces, and then contextually change alif shape when it follows the lam.