Dynamic spacing arithmetic/ Update Metrics bug

Hi there,

big fan of glyphs! I keep running into an issue on my font file lately, though. I am using dynamic spacing/sidebearing arithmetic (calling a lot to OHno). Lately when I go to update the spacing on base glyphs like O/H/n/o, the red update warning shows on other glyphs using that letter as the sibearing value, but when I click "Update metrics (either manually or by the “Update metrics” menu function), it changes the base glyph’s sidebearing value rather than updating the linked glyphs. About 2 or 3 months back I ran “Steal Metrics” by Mekka Blue to copy over spacing between masters in the file. Could that somehow be causing these issues? Or has anyone else experienced this?

This Loom video shows it happening. And oddly, the bug doesn’t always happen when updating metrics, only every so often. In the video you can see the update metrics works fine until it gets to the capital I. Loom | Free Screen & Video Recording Software

The only way I have been able to work around is to retype in the character into the sidebearing on the offending glyph. But sometimes even that doesn’t work. For example, right now I cannot get any dynamic sidebearings on “I” to behave, even after removing and retyping. It’s time consuming to not be able to use a bulk “Update metrics” because I can’t know when it will work.

Thanks for any advice!

Are you using components anywhere? To me, it looks like you could be using the I as a component in the H, so if you update the metrics in the I, which are inherited from the H, the components shift in the H, meaning the sidebearings change, meaning the circle starts all over again.

Unrelated tip: you can select all glyphs and click Glyph > Update Metrics (+ press Option for All Masters)

Thank you so much @SCarewe - That’s exactly what’s happening! I knew it had to be user error somehow. Super appreciate the quick feedback.
Yep, now that I know what’s causing it, I’ll fix and be able to use the mass select “Update metrics” again. I was afraid to before when I couldn’t tell what was causing the metrics to change. :slight_smile:

Great to hear that was easily resolved :slightly_smiling_face: This is why it’s always a good idea to facilitate automatic alignment where possible. Never mix components and paths in a glyph, for instance, as you can’t control the alignment correctly and things will get broken.

In this case, I would either recommend decomposing the I component in the H, or using a component (called something like _UC_stem) that you paste into the I and the H. Point being that you never really want to touch the sidebearings of components, as they shift otherwise (consider using metrics rules like =50 on both sides to guarantee fixed metrics).

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Thank you for the tips! I’ll be making the adjustments today :slight_smile: