whoa-var-debug's Introduction

Debugging Defaults in 4-axis Variable Font

When generating a variable font with fontmake v1.9.1(and 1.9.0), I experience the following weird results in Adobe Illustrator and Photoshop. I think I've isolated the issue coming from the default values that are used when defining the axes in the designspace file.

Using the designspace file named whoa-test.designspace, everything generates correctly.
Using the designspace file named whoa-test-mangled.designspace, the outlines appear mangled in Photoshop and Illustrator. The only thing that has changed is that the default values for each axis are set to an intermediate master, not an extreme.

Notes

Only the H glyph is included in the example files
Both files work fine in Fontview and Chrome. The issue only appears in Adobe applications.
In this font, there are 4 axes, each with a negative min, and positive max. Then there are also masters for the 0 values(intermediate center). Leading to 81 masters, to handle all the permutations of -1,0,1 with 4 masters :) Ideally, I'd like the default to be 0 for everything.
I've tried with a singled, filled in H, and get the same results. In other words no outlined/stroke style, and only one H just following the path of the topmost H. I don't believe it's due to the complexity of the outline. Sorry for not providing this in the example files, but I can do so if that's helpful.
UFO's are generated from Glyphs.
Glyphs can generate the variable font, but it seems to mix masters. Moving the scale slider, will instead rotate the glyph sometimes. I think there's a bug in their generation code?