source-serif icon indicating copy to clipboard operation
source-serif copied to clipboard

Interpolation problems in `SourceSerif4[opsz,wght].ttf`

Open behdad opened this issue 2 years ago • 5 comments

Hello!

This is an automatically-generated report about possible interpolation problems in SourceSerif4[opsz,wght].ttf, as found in the Google Fonts catalog.

To download a PDF version of this report with helpful visuals of the problems, click here; Or to view it on the GitHub website, click here.

The report follows:

Glyph uni20A6 was not compatible:
  Masters: '', 'opsz=8.0':
    Contour 0 structures differ: '', 'opsz=8.0'

This report was generated using the fonttools varLib.interpolatable tool. We understand that sometimes the tool generates false-positives. Particularly for more complicated font designs. If you did not find this report useful, please accept our apologies and ignore / close it.

To give feedback about this report, please file an issue or open a discussion at fonttools.

behdad avatar Nov 23 '23 13:11 behdad

Sorry for the noise.

behdad avatar Nov 23 '23 20:11 behdad

I was also tempted to close this at first, but I think it's worth a second look. The interpolation is fine, but you'll see that points are "wandering" (moving across a long distance).

I'll make an edit as soon as I find a moment.

frankrolf avatar Nov 24 '23 07:11 frankrolf

Hi Frank. Do you find this useful? It's a kink detector.

SourceSerif4[opsz,wght].ttf.pdf

behdad avatar Nov 25 '23 20:11 behdad

Hi Behdad, thank you for this. I am aware of those kinks, but I don’t think there’s a way around them (except HOI). I have made my own kinking reporter in RoboFont, and I left those points in deliberately – otherwise, the style of the terminal would have been compromised.

It’s tempting to flag those kinks as an error since it’s technically possible – however I don’t think they are very relevant. A typeface in which all outlines are completely smooth isn’t necessarily better than a design where kinks may occur – especially if we consider the intended application size.

With respect for this work, and without any judgment – flagging those could be interpreted as “missing the forest for the trees“. :-) Still, I think it’s useful for the designer to be informed of kinking, so they can make a decision whether they are avoidable.

frankrolf avatar Nov 26 '23 11:11 frankrolf

Thanks Frank for the feedback. I was still tuning my tool. With current default settings it doesn't report those anymore. It does catch major kinks that the designers want to fix.

behdad avatar Nov 26 '23 15:11 behdad