Are you plagued by little yellow triangles in your Glyphs.app project?

Glyphs gives us a powerful language for specifying sidebearings by referencing the values of other glyphs. This is useful, but can lead to some problems. For instance, you might set the left sidebearing of Dcaron to be equal to D, which in turn is equal to H. But, if you edit H, the derived sidebearings will no longer be correct. This requires tedious manual upating to fix.

You can also set up situations where A depends on B which in turn depends on A... a circular dependency that can't be resolved.

MetricsSolver is a plugin for Glyphs.app that attempts to resolve all metrics for all glyphs in your font, across all masters. It does this by building a simple dependency graph for each glyph, and resolving the metrics on the referenced glyphs first. It'll also warn you about typos and circular dependencies in your metrics keys.

To use it, just select "Resolve All Metrics" from the "Edit" menu.

Caveats:

• The font view tab won't automatically update; to get rid of the little yellow triangles just scroll the view.
• Some metrics may have rounding errors(?) and won't resolve completely no matter what. I'm not sure what the cause or fix is for this.
• This plugin has only been tested against my own work; feedback and (especially) pull requests are welcome!