Re: [CSSWG] Minutes and Resolutions 2010-03-17

John Daggett:
> 
> Name:    character-transform
> Value:   normal | inferior | ordinal | subscript | superscript
> Initial: normal

Before I read John Hudson’s mail I thought ‘subs’ and ‘supr’ only applied to digits whereas ‘ordn’ and ‘sinf’ included letters, since the descriptions on <http://www.microsoft.com/typography/otspec/featurelist.htm> read that way. I would then have had suggested values to enable these separately, but it seems we should combine ‘subs’ and ‘sinf’ anyhow and perhaps we also can combine ‘supr’ and ‘ordn’.

If ‘vertical-align’ is either ‘sub’ or ‘super’ we can guess the proper transformation to do, so authors should only have to specify ‘auto’. I also like ‘index’ for ‘subs’, ‘sinf’, ‘supr’ at least. The equivalent AAT feature is ‘Vertical Position’; the AAT feature spec <http://developer.apple.com/fonts/Registry/>, though less relevant today, is much more readable than the OT one, by the way.

If someone comes up with a usecase where you wouldn’t alter ‘vertical-align’ – and it’s possible I just missed it since there are several hundred unread W3 mails in my inbox – we could introduce finer control (especially ‘ordinal’), but till then I don’t see what’s wrong with this:

  character-transform: _normal_ | auto   (inherited)

  ‘normal’:  -subs -sinf -supr -ordn / ‘No Vertical Position’
  ‘auto’:    +subs +sinf / ‘Inferiors’ where “vertical-align: sub”,
             +supr +ordn / ‘Superiors’ where “vertical-align: super”

Since AAT ‘Ordinals’ value is hardly supportable this way and if ordinals are really too different from superiors, “ordinal || index” replaces (or augments?) ‘auto’:

  ‘ordinal’: +ordn / ‘Ordinals’
  ‘index’:   +subs +sinf / ‘Inferiors’ where “vertical-align: sub”,
             +supr / ‘Superiors’ where “vertical-align: super”

Although ‘normal’ is initial, ‘auto’ should be default for phrase level elements in UASSs.

 sub, sup {
   line-height: normal;
   character-transform: auto;/* will fall back to 
      font-size: smaller or some better emulation */
 }
 sub {
   vertical-align: sub;
 }
 sup {
   vertical-align: super;
 }

PS: I’m probably ignorant or lazy again, but why is this not a ‘font-variant-*’ property?

Received on Wednesday, 24 March 2010 22:50:38 UTC