Variable font "width" snaps incorrectly depending on "weight" for multiples of 100

[herbst]

I'm running into a bug where Affinity Publisher seems to incorrectly handle variable font weights.

Whenever the font weight becomes a multiple of 100, the font width "snaps" to a different value – this seems to be whenever Affinity decides that this is a "preset", e.g. "Bold", "Medium" and so on, so weight multiples of 100.

A workaround is setting the font width to a non-default value – say, 99.9 instead of 100.0 – which prevents that snapping from happening.

Here's a screen recording:

- in the first half you can see me changing the weight. Whenever the number is a multiple of 100, the dropdown goes to a specific style name, but the "width" seems to jump away from the set value of 100 to "something else".

- in the second half, I adjust the "width" to be 99,9 instead of 100, and repeat the process. Now, it never "snaps" to one of those different weights anymore, which I think is the correct behaviour - when adjusting the "weight" slider, only the "weight" changes and I get what looks like "good" variable font behaviour.

- I would expect the behavior of dragging the weight slider to match what happens when dragging the weight slider on https://fonts.google.com/specimen/Nunito+Sans/tester – only the weight changes.

 

The font in question is Nunito Sans Variable from Google Fonts: https://fonts.google.com/specimen/Nunito+Sans. I attached the ttf file for convenience.

 

 

 

 

 

NunitoSans-VariableFont_YTLC,opsz,wdth,wght.ttf

[Hangman]

Hi @herbst and welcome to the forums,

This looks like a known bug in version 2.5.7 logged under AF-5244 which is currently awaiting a fix...

Except for a weight setting of 200 to 201, holding the Alt key while dragging the Weight slider seems to give the expected smooth transition...

[herbst]

Hi, I looked at the referenced issue and while it may be related I believe it's a separate issue. Here, the weight adjusts correctly; but other font axis "snap" to values they should not change to while adjusting the weight.

Holding the Alt key only appears to give a smooth transition because it most of the time jumps above the multiples of 100, going from e.g. 298 to 303, thus avoiding the issue. If you hold Alt and try to hit one of the 100's then the same issue appears. 

[Hangman]

Hi @herbst,

It seems to be influenced by the Optical Size setting. For me, this defaults to 12 and I see jumps between:

• 360 → 400 → 440
• 560 → 600 → 640
• 760 → 800 → 840

Changing the Optical Size to 6 results in a smooth transition but yes, regardless there is something not right... The font weights in 2.5.7 are also not shown in the correct order, i.e., they're shown alphabetically instead of weight though that may not be the issue here...

[herbst]

For me, changing any of the values to a non-default value results in the correct behaviour (not just optical size).

Summary:

• width != 100 -> I can smoothly adjust weight ✅
• opticalSize != 12 -> I can smoothly adjust weight  ✅
• YTLC (e height) != 500 -> I can smoothly adjust weight  ✅
• width == 100 && opticalSize == 12 && YTLC == 500 (all the default values) -> I can not smoothly adjust weight, there are jumps on the 100's ❌

[Hangman]

1 hour ago, herbst said:

For me, changing any of the values to a non-default value results in the correct behaviour (not just optical size).

I'm seeing the same behaviour in the 2.6 Beta...

Interestingly, this seems to be Mac-specific, the weight slider for Nunito Sans performs correctly on Windows...

Someone in the moderation team at Serif should hopefully pick this thread up and log the issue accordingly...