Re: [css3-writing-modes] Character's intrinsic orientation

On 06/04/2011 07:21 AM, Eric Muller wrote:
>
> I think you have another problem with arrows. U+2190 โ† LEFTWARDS ARROW is EAW=A, Gc=Sm, sc=zyyy (common), so it's horizontal;
> I think you want vertical/translate. Similarly for the non-JIS arrows, e.g. U+219A โ†š LEFTWARDS ARROW WITH STROKE, ea=N,
> Gc=sm, sc=zyyy.

All of the arrows are rotated by default. Making some arrows rotate and others not
rotate seems to me a very bad idea.

> Finally, I remain unconvinced by the use of EAW, which has, IMHO, no place in modern Unicode implementations, at least those
> that do not deal specifically with JIS. For example, U+0391 ฮ‘ GREEK CAPITAL LETTER ALPHA has eaw="A" and while U+1F09 แผ‰ GREEK
> CAPITAL LETTER ALPHA WITH DASIA, which is canonically equivalent to <0391, 0314> has eaw="N".

The problem you cite is not a problem with the current definitions in the spec,
because we do not use EAW to determine the orientation of letters.

> I am  a bit confused by 5.1.1; when does it apply? Hasn't the text before that
> section answered all the questions?

Hm, yes the first paragraph is repeating the information above. I can try to
edit the text to avoid that.

> In any case, I don't like:
>
> "The orientation of characters belonging to the Common, Inherited, and Unknown script
> categories may be UA- or font-dependent in vertical typographic modes:"
>
> I believe that the author of a document has be able to control the final appearance.

I believe that the default behavior should try to do the right thing in as many
cases as possible, and that the ability to map codepoints to custom orientatations
does not belong in this level of CSS. Within those constraints, the current spec
is the best I've been able to come up with. I don't understand how to incorporate
your request within those constraints; you will have to give me an example.

> Also, AFAIK, the vrt2 feature is not used by anybody. It is the result of misconception
> of the way layout engines are written.

So I'm getting conflicting information from you and Ken Lunde as to whether vrt2 should
be used for anything. Wrt pre-rotated Latin, I don't see that as useful or necessary.
But wrt punctuation and symbols, it seems to me that if the font has something to say
about the correct orientation of those for that font's character design, it should be
followed.

~fantasai

Received on Saturday, 4 June 2011 00:43:31 UTC