[mpeg-OTspec] Registering new GPOS features?

[Behdad Esfahbod]

'dist' feature?

On Mon, Apr 23, 2018 at 2:21 PM, Ken Lunde lunde at adobe.com [mpeg-OTspec] <
mpeg-OTspec-noreply at yahoogroups.com> wrote:

>
>
> John,
>
> That concern was mentioned earlier on in the blog article:
>
> > ...and while the existing kerning features were discussed as a possible
> vehicle for such metrics information, there is an obvious conflict for
> fonts that are intended to supply genuine kerning values versus contextual
> spacing values that generally used fixed values and affect a much smaller
> number of glyphs.
>
> In other words, Japanese fonts that include genuine kerning data in these
> two GPOS features, kern and vkrn, also include metrics information in the
> palt and vpal GPOS features that also need to be turned on, which generally
> makes the kana proportional, along with most of the punctuation and some
> symbols, plus kerning values, some of them subtle, on top of all that.
> That's a bunch of metrics complexity that simpler environments that have no
> line-layout support whatsoever, which may merely want to get rid of unused
> "space" in full-width brackets and other full-width punctuation, in the
> form of half or a quarter of an em.
>
> Regards...
>
> -- Ken
>
> > On Apr 23, 2018, at 2:46 AM, John Hudson <john at tiro.ca> wrote:
> >
> > On 22-04-2018 22:14, Ken Lunde lunde at adobe.com [mpeg-OTspec] wrote:
> >> Vladimir,
> >>
> >> When is the next opportunity for registering new features? I ask,
> because I may have a couple in the proverbial hopper:
> >>
> >> https://blogs.adobe.com/CCJKType/2018/04/contextual-spacing.html
> >>
> >
> > From that discussion paper:
> >
> > 'Our meeting ended with lunch at PHB, along with the idea to register
> two new OpenType
> > GPOS (Glyph Positioning) features that would be tentatively tagged
> 'cspc' (“Contextual
> > Spacing”) and 'vcsp' (“Vertical Contextual Spacing”), and which would
> behave like the 'kern'
> > and 'vkrn' in that they adjust inter-glyph spacing.
> > ...
> > 'In order to be able to test in environments that do not support
> arbitrary OpenType
> > features, the example font includes the lookups for the 'cspc' and
> 'vcsp' GPOS features
> > in the 'kern' and 'vkrn' GPOS features, respectively.'
> >
> > Can you explain why you want to register two new features for this,
> rather than just putting the lookups in the 'kern' and 'vkrn' features as
> in this demonstration?
> >
> > JH
> >
> > --
> >
> > John Hudson
> > Tiro Typeworks Ltd
> > www.tiro.com
> >
> > Salish Sea, BC
> > tiro at tiro.com
> >
> >
> > NOTE: In the interests of productivity, I am currently
> > dealing with email on only two days per week, usually
> > Monday and Thursday unless this schedule is disrupted
> > by travel. If you need to contact me urgently, please
> > use some other method of communication. Thank you.
> >
>
> 
>



-- 
behdad
http://behdad.org/
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