First of all: Thank you very much for this awesome program!
I’ve stumbled across a minor issue in the OpenType Designer: When a diacritical mark is placed on the first character of a kerning pair, it seems to be moved by the kerning value just like the second character of the pair. A screenshot shows it better than I can explain it: Some additional info:
- ᝆ + ᝆ (two times Buhid letter Ta) is a kerning pair with a kerning value of -300.
- The Combining Vowel Sign I is placed on the Ta using a Mark to base attachment lookup.
- In the kerning lookup, Process Marks is set to None; otherwise the mark would prevent the kerning entirely.
- The mark is only shifted in this preview. After exporting the font, it looks just fine e.g. in Firefox: The kerning is applied, and the mark is where it should be.
This issue is a minor thing as it only happens in the preview and does not affect the actual outcome. But it can mislead the user into thinking they’ve done something wrong.
Kind regards,
Alexander Lange