fs_selection WWS bit should be 0 if no name ID 21 and 22

[ollimeier]

Hi,

according to Microsofts OT Spec the fsSelection bit 8 (=WWS) should be set if name ID 21 and 22 are NOT used.

Many typographic families contains faces that differ only in one or more of the attributes weight, width and slope. Even though a family might have a large number of member faces, if the variations are in these attributes only, then family and subfamily names provided in the 'name' table using IDs 1 and 2 or 16 and 17 will be consistent with a weight/width/slope family model. In this case, bit 8 should be set, and 'name' entries for name IDs 21 and 22 should not be included.
https://docs.microsoft.com/en-us/typography/opentype/spec/os2#fsselection

Currently, the following code does not take care of this:

gftools/Lib/gftools/fix.py

Line 224 in f0d02b3

fs_selection &= 1 << 7

Cheers,
Olli

[ollimeier]

It should include something like:

    name_table_obj = font_obj['name']
    name_id_21 = name_table_obj.getDebugName(21)
    name_id_22 = name_table_obj.getDebugName(22)

    if name_id_21 is None and name_id_22 is None:
        fs_selection = font_obj["OS/2"].fsSelection
        fs_selection |= 1 << 8
        font_obj["OS/2"].fsSelection = fs_selection

[m4rc1e]

Thanks for both the issue and PR.

Are you planning on using gftools to release families which may have Condensed/Expanded styles etc? I'm afraid atm, this isn't possible.

I'd be interested to hear your requirements since I'd like us to make the tools in this repo more flexible.

[ollimeier]

@m4rc1e Thanks for your patient feedback. As mentioned in the PR, it seems my understanding of the use of the wws bit differs a bit from yours. Even thou I 'separate' the family into their 'wdiths', I set the wws bit when I don't use name ID 21 and 22.

[m4rc1e]

Our name records and bit settings are specific to Google Fonts. They may not follow best practices. However, please note that Source Sans, Source Serif etc also do not contain either the WWS bit or nameIds 21,22. The only families we serve which do have the WWS bit enabled are Noto since they also contain width variants so it does fulfil the WWS model.

@twardoch I seem to remember you may have had a hand in deciding name records and bit settings?

[m4rc1e]

@moontypespace do you know of any repercussions for not enabling the bit, even if the family only contains normal widths?