Not all variable font axes work.

[thomgb]

I have a font with 3 axes. One interpolates (wght) two don't (STEP, ANGL) = featureVariations. With fontVariations() wght and ANGL work fine, but STEP doesn't. STEP sometimes(?) behaves like ANGL...

In FontView all works fine.

[typemytype]

could you provide an example font?

[thomgb]

Sure. PanType.zip

[justvanrossum]

Can you verify the font works as expected in a browser, say, with Axis-Praxis? We can't rule out that there are bugs in the OS support for FeatureVariations. I'm not sure which browsers use which parts of OS support for variable fonts, though.

[typemytype]

and what OS are you using?

variations works half and half on 10.10

[thomgb]

i'm on 10.13

In AP all works good. :)

[justvanrossum]

Ha, it works even in Chrome on 10.10 :) So apparently Chrome doesn't use (much of) CoreText.

[justvanrossum]

I sent Thom a script that works directly with CoreText and that seems to display the same problem. So: either we're not using CoreText correctly (my script roughly does the same as DB), or CoreText has a bug with FeatureVariations. I optimistically guess it's the latter :)

[thomgb]

The same Axis-Praxis test in Safari failed! Must be a CoreText bug.

[justvanrossum]

Yes, everything now points to this being a CoreText bug. @thomgb, I assume you are on the latest version of 10.13? @typemytype, do you know who to contact at Apple about this?

[thomgb]

@justvanrossum indeed 10.13

[litherum]

You can file a bug at bugreporter.apple.com. If you do that, please post the bug number so I can make sure it doesn't fall through the cracks.

[justvanrossum]

I think @typemytype filed an issue, and it seems Paolo found it. Frederik, do you have an issue number to share here for reference?

Let's leave this issue open until there's a confirmed fix from Apple.

[typemytype]

got notified that is has been resolved in the latest macOS 10.13.4beta, I dont have time to install it...