Pre-Interpolation filters?

Scripting
1

Hello, is it possible to call a filter in an instance before it is interpolated?

For example: I have a font which uses different corner components between masters. I want to decompose them (because they are compatible) before the instance is interpolated.

I can of course simply run a filter on the whole font before exporting, but that’s annoying. Is there some way of setting this up as a parameter in the exports?

2

Yes, use a “PreInterpolationFilter” CP.

3

Okay, thanks. I couldn’t find that in the list. I knew there was something like PreInterpolationFilter, just didn’t realise it’s a hidden parameter.

Thanks!

4

I can’t get this to work.

This is my filter:

@objc.python_method
def filter(self, layer, inEditView, customParameters):
	for corner in layer.allCorners():
		layer.removeHint_(corner)

Even just writing print("Hello") doesn’t print anything when used as a PreInterpolationFilter.

My goal is to remove all corner components in all layers before interpolation. Is this doable?

5

Why before interpolation?
If you like to export without the corners, you can add a “Remove Glyphs” parameter that contains the corners.

6

Ah! That’s smart. Thanks.

How about for decomposing corners? I need to do this before interpolation, because the file has different corner components between masters (so, incompatible), but they are compatible after decomposition.

7

Does your filter work (meaning the print() shows) when run as a “Filter”?

8

Yes.

9

Can you try adding:

def processGlyph_withArguments_(self, glyph, arguments):

(without the @objc.python_method).

10

Excellent, that works. Thank you!