Transforming/editing glyphs with fonttools?

Jon Palmisciano

Hello everyone!

I'm diving back into fonttools again and am wondering if there is a way to transform/edit glyphs with fonttools. Here are some examples of workflows I'd want to be able to do:

• Scale all the glyphs in a font horizontally to 125% width. (Yes, I know this is a type crime, but this is for an experiment, not production use.)
• Find all points touching (or close to) the baseline and shift them down by 10 units.
• etc.

I browsed the fonttools API this morning and found the pen classes, but those seem to be for drawing glyphs from scratch as far as I can tell. Does fonttools support editing glyphs as I've described? If so, are there any examples out there? I searched this morning but couldn't find anything, which led me to ask here.

Simon Cozens

It's much easier to do this stuff at the UFO level. Fontmake supports filtering UFOs, including a filter which mimics the Glyphs "Transformation" filter. See https://github.com/googlefonts/fontmake/blob/main/USAGE.md#outline-filtering

Jon Palmisciano

I'll check that out. Thank you, Simon.