X Height Snapping Exceptions in ttfautohint setting not working as expected

Hi, i stumbled upon a problem with ttfautoninting bundled in Glyphs app.

According to specifications of ttfautohint the x Height Snapping Exceptions sholde work like this:

A list of comma separated PPEM values or value ranges at which no x height snapping shall be applied. A value range has the form value 1 - value 2, meaning value 1 <= PPEM <= value 2. value 1 or value 2 (or both) can be missing; a missing value is replaced by the beginning or end of the whole interval of valid PPEM values, respectively (6 to 32767). Whitespace is not significant; superfluous commas are ignored, and ranges must be specified in increasing order. For example, the string "7-9, 11, 13-" means the values 7, 8, 9, 11, 13, 14, 15, etc. Consequently, if the supplied argument is "-" , no x height snapping takes place at all. The default is the empty string ( "" ), meaning no snapping exceptions.

Paste or type values in input → press OK
Values saved only if there is a single value in the input. Like 10 or 2
In all other cases value is reset to default (empty).

Please help. Maybe i’m not getting something, or maybe it’s a bug.

True, that is a UI bug.

Workaround: paste the parameter in a text editor, edit it there and paste it back into the custom parameters.

Or use the mekkablue script Hinting > Set TTF Autohint Options. It batch-sets it for all instances that have a TTFAutohint Options parameter at the same time.


1 Like

Thanks for the fast reply!

If i use the makkablue script will i see the modified parameter in the instance table? Or it’s doing some “under the table” modifications?

Sorry, for bothering, don’t mind the question. Reread your reply & understood how this works.

I fixed it.