Anchors & decomposition

Glyphs
#1

If the base glyph has two anchors (for example “top” and “top_right”), is there some way to ensure the accent is attached to the intended anchor when decomposed*?

*Not the kind of decomposition that happens inside Glyphs where you turn components to outlines, but the kind where you split an accented letter into base letter + accent glyphs.

#2

Hmm, it has to go into the mark feature somehow. I assume you understand the inner workings of that feature in AFDKO code?

  1. In the worst case by opening the features.fea and adjusting the respective mark feature. But that is tedious and easy to forget because you would have to do it every time.
  2. Or by an additional GPOS rule that kerns the mark from the top position to the top_right position, but that does not interpolate.
  3. Or you use topright (next to top in the base glyphs) and _topright (instead of _top in the mark) as anchors. That should open an additional lookup in mark.
  4. Or you use a GSUB rule that flips the mark for an alternate with a shifted _top.
#3

Hmm.

I have a basic grasp of the mark feature, yes. The context of my question was a little misleading. Actually, I have two stacked marks (ḗ). So what I want to achieve, is – given a specific context – to attach the mark to a different anchor, e.g:

• Use the regular “top” anchor to position the macron in ē
• Use the “top_lower” anchor to position the macron in ḗ.

Is that possible? Without adding a new glyph? Keep in mind, I am only talking about decomposed rendering.

#4

A kern wouldn’t work, right? Would it not be overridden by the mark positioning?