[MPEG-OTSPEC] Possible edit for LTSH and b64k

[Takaaki Fuji 藤 貴亮]

Thank you so much! As for versioning I have no particular opinions and whatever is fine.

Regards,

Takaaki Fuji

> On Feb 3, 2024, at 3:31, Behdad Esfahbod <behdad at behdad.org> wrote:
> 
> Thank you for this. I filed the following issue with a proposal:
> 
>   https://github.com/harfbuzz/boring-expansion-spec/issues/132
> 
> behdad
> http://behdad.org/
> 
> 
> On Thu, Feb 1, 2024 at 10:46 PM Takaaki Fuji 藤 貴亮 via mpeg-otspec <mpeg-otspec at lists.aau.at> wrote:
> Hello all,
> 
> Sorry if I missed past discussions, but I found LTSH might also need a small change for the b64k proposal, where the 'numGlyphs' field is uint16.
> 
> I checked the fonts currently available in macOS and Windows, and still a number of fonts include a set of VDMX/hdmx/LTSH table, possibly generated with the Microsoft’s CacheTT tool. I also found out that B612 (https://b612-font.com) is one of the recent fonts with those tables.
> 
> For b64k fonts, I suppose just capping this field at 65,535 should suffice as you can put an arbitrary number of 'yPels' in the table anyway. Like the 'sbix' table, putting a line like
> 
> > The glyph count is derived from the size of the ‘GLYF’ table when present, or from the 'maxp' table. 
> 
> into the description sounds nice to make sure b64k-aware clients should ignore the ’numGlyphs’ field in this table.
> 
> So, in case this table is still in use, we might want to make a small edit. What do you think?
> 
> Regards,
> 
> Takaaki Fuji
> 
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