Re: [css3-fonts] Behdad's Feedback on CSS Fonts Module Level 3 Editor's Draft 5 April 2010

On 08/19/10 16:53, Chris Lilley wrote:
> On Thursday, August 19, 2010, 8:08:16 PM, Behdad wrote:
> 
> BE> On 08/17/10 05:12, Jonathan Kew wrote:
>>> In that case, I suggest we should have a new property called "font-extend" that would take a scaling factor to be applied to the glyphs and metrics in the x-direction (or rather, along the direction of text layout, so for vertical text it would apply in the y-direction). A font-extend value of less than 1.0 would actually compress the glyphs, of course. And negative values ought to reflect the glyphs and reverse the text direction, so that <span style="font-extend: -1.0">mirror writing</span> becomes easy to express.
> 
> BE> Watch out!  Mirroring text that way has bidi implications.  Mirror an RTL span
> BE> and it should be processed as LTR during bidi now. 
> 
> Well, no. It would look like rtl text in a mirror. With the glyphs backwards, and everything.

Not when you mix it.  Believe me.  If you have an Arabic sentence with a Latin
word in the middle, normally you have an ordering of characters like this:

  10 9 8 7 4 5 6 3 2 1
  <------- ----> <----

Where the '456' is the Latin word.  Now if you use a mirrored font for your
Arabic only, you get the ordering of characters this way:

  7 8 9 10 4 5 6 1 2 3
  -------> ----> ---->

Which is wrong.  It should be:

  1 2 3 4 5 6 7 8 9 10
  ------------------->

Because now your Arabic is read LTR, not RTL.

behdad

Received on Thursday, 19 August 2010 22:23:17 UTC