Contextual Mark Attachment

[abdrhnf (Hanif)]

Contextual Mark Attachment in vocalised Arabic

I have try useMarkFilteringSet as i see on another thread, but i don’t understand how it works and what anchor/mark glyphs should i include to the Mark Filter Class. my solution for now i am created another duplicated glyphs as contextual alternate with new mark position. I really like this contextual mark feature to be explained more as this very helpful for developing arabic fonts that based on handwriting calligraphy.

i’ve ask this thing last year, it might help