SVG color font and vertical metric issue

Glyphs
1

All the softwares in which I am testing a color font are interpreting vertical metrics differently. Only LibreOffice gets it right, and I suspect that is because it supports CPAL/COLR and so doesn’t present the same issue as other softwares that support only SVG.

Is it a known issue, and is there a way to workaround it? I am not an expert in color font technology so I have trouble to understand where this could come from.

note: by “all softwares” I mean TextEdit, Page, Word (Mac and Windows). Indesign is a different system so not included here.

Update:

  • On Word Windows and Mac: there is a “space after” of 8pt that is set by default. Removing this, makes the interline “1” behave as expected. I must have removed it when I tested the non-color font and forget about it when testing the color font.
  • Native text editors on Mac: no idea and I give up.
2

What exactly happens? As soon as you add an SVG table, the vertical metrics stop working as expected?

3

It may be something else actually. The non-color font doesn’t have « guidelines » in the background, while the color font does. I exported a non color variant with guidelines and noticed the same vertical metric issue. Interline space is added for the variant with guidelines.. maybe MacOS reads the bounding box of some basic glyphs and reinterpret metrics to avoid clashes :woman_shrugging:

4

Can you check the winAscender and winDescender in both fonts?

5

I had the same thought at first but the interline displayed in the version with guidelines is smaller than what I set for the usWin metrics (and it’s the same values in all styles).

Few years back I noticed that the first baseline in TextEdit was displayed according to the bounding box of Agrave, I wonder if there is something similar at play here.

I can send you the files if you want to investigate but my priority was Windows, I gonna give up on this one for now.