[MPEG-OTSPEC] Vertical Writing: Character Orientations are Sometimes Uncontrollable

[Levantovsky, Vladimir]

On Friday, August 7, 2020 10:41 PM, Eric Muller wrote:

The link between layout engines and fonts is the 'vert' feature. So what
Murata-san wants is for the 'vert' feature to behave according to some
known fixed rules (of course, the UAX50 rules are an obvious choice, but
by no means necessary), rather than the current situation where MS
Mincho does it one way and Meiryo does it another way. I can only see
two solutions, after having picked the rules: 1) we fix the fonts that
do not follow the rules or 2) we switch to a new feature that
specifically imposes the rules (and may be fallback to 'vert') . I
suspect that 1) is not an option.

A couple of observation points:

1.       I’d like to remind us all that the most recent amendment (published in June this year) addresses, among other things, the description and application of the ‘vert’ feature to bring it in compliance with UAX50. These changes were initially introduced as a proposal from Ken Lunde, back in 2017, and then discussed and agreed by the group, before making it into the formal input contribution as a basis for the latest amendment.

2.       Speaking about two possible solutions outlined by Eric:
1) Fixing _some_ fonts that do not follow the rules would be my preference. The specification of ‘vert’ feature has just been amended, and it is only natural to expect that implementations should be updated as well to make them conformant to the spec. Yes, it may [and, likely, will] take some time, but I think this is still a better choice than
2) Switching “to a new feature that specifically imposes the rules” means that _all_ fonts have to be updated to implement this new feature! If option 1) requires some work, then option 2) requires more work – how is that an improvement? On top of that, having two features to address the same functionality isn’t ideal, and will only add more confusion, IMHO.

Thanks,
Vladimir

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.aau.at/pipermail/mpeg-otspec/attachments/20200810/ecdb887f/attachment.html>