TT exports contain nested components

Hi, when using FontBakery to check our exported TTFs, it always complains that they contain nested components, which apparenty is a Bad Thing in both static and variable TT fonts.

And, in fact, FontBakery is right: the accent on uni1EAE (Abreveacute) gets shifted to the right and is no longer centred above the apex of the A; this is visible when rendering with FreeType or reopening the TTF in Glyphs again.

Apparently, the TT export behaviour changed in version 2.4.2: If you have nested components, and export a TrueType, more components are kept, and less decomposition happens. (new in Glyphs 2.4.2:

Exported TTFs in Glyphs 2.4.1 don’t generate this error, as the double accents are all placed individually on top of the A. The new behaviour also remains the same in Glyphs 3 (we normally use 2.6.2).

What exactly was supposed to have changed in Glyphs 2.4.2? Is creating buggy TTFs with nested components really the expected behaviour of Glyphs or is it a bug?

Is there a solution for this problem other than scripting to rebuild such glyphs on export (e.g. via a custom parameter)?

1 Like