[compatibility cheker] Allow empty non-default glyphs #1163
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
made the Bold 'space' glyph non-empty (the default 'Regular' is still empty) to trigger error when default is empty but non-default is not. also added 'E' glyph which is non-empty in default 'Regular' master but it is empty in the non-default 'Bold' master. This should be allowed and pass the check, not raise an error. The empty non-default glyph should be treated as if it is not there. This is to add support for sparse kerning.
unrelated to this PR, flake8 complains about "Exception class with `__init__` should pass all args to `super().__init__()` in order to work with `copy.copy()`"
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
fonttools varLib already treats empty glyphs in non-default masters as non-participating ('sparse') in gvar interpolation.
But fontmake's compatibility checker currently rejects these as it expects all glyphs to have the same number/type of segments.
In fonttools/fonttools#3956 we relaxed this requirement in cu2qu. So we can now let fontmake pass these through.
Adding empty non-default glyhps can be useful for defining masters that only contribute kerning data. The kerning.plist needs the glyphs to be present in the UFO default layer, otherwise the the pair referencing any missing glyphs will be pruned by the ufo2ft kernFeatureWriter. By adding empty glyphs, the kerning pairs can stay and the ufo2ft's VariableKernFeatureWriter can generate a variable kern feature, but no additional gvar deltas will get added for those glyphs.
Fixes #1158