Avar: Axis value map out of order

1

Hello, I am running into a consistent Fontbakery warn. I exported a variable font with Axis Location parameters set in all masters and active instances. I ordered the axes: wdth–wght–ital.
Upon export, I get:

ots-sanitize passed this file, however warnings were printed:

ERROR: avar: Axis value map out of order ERROR: Table discarded

When I remove the Axis Location parameters from the instance, this warn is no longer printed. What can I do to remedy this? Thanks!

2

It seems that the instance map to values are bigger or smaller than what the masters defines as the mapped space.

3

@SCarewe did you ever find a solution here? I’m having a similar issue in a Weight + Slant VF. I’ve triple-checked, and it seems that the axis location values (and resulting avar table, when inspected with TTX) are fine, and a good match between Masters and Exports.

The font in question does have a Hairline Export that is at wght=50, and maybe this is relevant?

4

Okay, solution found, at least in my current case.

It should work to set up a Slant axis with arbitrary values (such as 0 and 8) for upright and slanted masters/exports, then use Axis Location parameters to map these to the OT spec-compliant 0 to -8 axis range. However, when using Glyphs to build this to a variable font, such a setup results in an avar entry for Slant that is “criss-crossed.” At least, this happened when I went to correct the Slant range and locations, without also changing the general Slant values for masters and exports. Here’s the before/after of the slnt avar entry:

  <segment axis="slnt">
-   <mapping from="-1.0" to="-1.0"/>
+   <mapping from="-1.0" to="1.0"/>
    <mapping from="0.0" to="0.0"/>
-   <mapping from="1.0" to="1.0"/>
+   <mapping from="1.0" to="-1.0"/>
  </segment>

Now that I’ve set up the general Slant axis values to be a negative range from the start, I’m passing the OTS check.

5

Can you send me the .glyphs file?

6

Can you post your avar table?