I’m new here.
I’m using FontLab to create OT kern table for a rtl (PersoArabic) font. Everything goes well except that kerning value, positive or negative, is applied to the right sidebearing of the glyph on the right. It’s rtl and the right glyph is paired with its left glyph not the previous glyph on the right. In rtl pair, I type the right one ﬁrst then the left one. If I have a kerning valure of -100 for example, this value is not applied to its left sidebearing as it should, but to its right sidebearing which brings the previous character which has nothing to do with this kerning pair very close or even superposed.
I hope I could explain the problem clearly for this mostly ltr minded crowd!
Kerning in rtl