I can only talk from a Persian perspective: This bulge is, flat out, unacceptable for Persian writers. I know that many Arabic fonts have this bulge, most famously Tahoma. But you can never see this bulge in any serious publication (look at newspaper front pages in jaaar.com and see if you can spot a single YEH with such bulge). None of the most popular Persian fonts (e.g. Nazanin, Mitra, Yagut, Yekan, Terafic, Titr, and Koodak) ever have this strange shape of YEH.
I suspect the addition of this bulge is due to the shortage of descendent space in Arabic script when it is paired with the Latin script: It's a "solution" to give YEH (one of the lowest letters in the script) enough space to enjoy it's curves without going below the lower base line.
But no matter the cause, such bulge is present only in some artistic calligraphy (and even there, it is rare) and simply does not exist in modern Persian writing.
I have actually modified the Ubuntu Arabic font to fix this problem, and also another problem with the isolated form of YEH. Please see the sketches attached. I am happy to also pass the .sfd file, though I don't think it's actually useful, since I made the curves without much delicacy.
And about "fitting with Ubuntu Latin font design," yes it is actually very nice. But I am sure that the modified shapes of YEH can also be made harmonized with the rest of the design.
I can only talk from a Persian perspective: This bulge is, flat out, unacceptable for Persian writers. I know that many Arabic fonts have this bulge, most famously Tahoma. But you can never see this bulge in any serious publication (look at newspaper front pages in jaaar.com and see if you can spot a single YEH with such bulge). None of the most popular Persian fonts (e.g. Nazanin, Mitra, Yagut, Yekan, Terafic, Titr, and Koodak) ever have this strange shape of YEH.
I suspect the addition of this bulge is due to the shortage of descendent space in Arabic script when it is paired with the Latin script: It's a "solution" to give YEH (one of the lowest letters in the script) enough space to enjoy it's curves without going below the lower base line.
But no matter the cause, such bulge is present only in some artistic calligraphy (and even there, it is rare) and simply does not exist in modern Persian writing.
I have actually modified the Ubuntu Arabic font to fix this problem, and also another problem with the isolated form of YEH. Please see the sketches attached. I am happy to also pass the .sfd file, though I don't think it's actually useful, since I made the curves without much delicacy.
And about "fitting with Ubuntu Latin font design," yes it is actually very nice. But I am sure that the modified shapes of YEH can also be made harmonized with the rest of the design.