You can check the Pango's script gallery (GNOME project) [0] as showcase of their prowess to be able to render Persian/Urdu that is the most complex form of Arabic script.
Complexity comes from the fact that in Arabic, a single character can have at max 4 contextual shapes generally speaking. In Nastaleeq variation, a single character can have up 100s of contextual shapes depending upon where it appears in the word.
Complexity comes from the fact that in Arabic, a single character can have at max 4 contextual shapes generally speaking. In Nastaleeq variation, a single character can have up 100s of contextual shapes depending upon where it appears in the word.
[0]. https://pango.gnome.org/ScriptGallery