Re: A property for font antialiasing control on Mac OS X



On Jul 17, 2013, at 6:00 PM, "L. David Baron" <dbaron@dbaron.org> wrote:

> On Wednesday 2013-07-17 17:04 -0700, Rik Cabanier wrote:
>> Other cases where you might want to turn off anti-aliasing:
>> - animations
>> when animating text, you don't want to anti-alias because of performance
>> and also because subpixel AA will cause "jiggling" of characters when you
>> move a text run
> 
> The jiggling is a result of subpixel *positioning* of text (which
> also requires re-rasterizing for the different subpixel positions,
> which integer shifts don't).  I think that's independent of
> antialiasing.

Right. And at least SVG has a CSS property to disable glyph alignment so that you don't see these jumps. The property is implemented in all browsers even though I forgot the name right now.

Greetings
Dirk

> 
>> - content that will end up in a 3d transform
> 
> Implementations already know how to disable subpixel AA here;
> authors don't need to give hints.
> 
>> - match canvas text
>> Text in canvas never uses subpixel-AA (although there are some browsers
>> that allow it) and an author might want to match HTML text with Canvas text
> 
> I don't think this is a strong use case.
> 
>> Maybe for background-clip you might want the text to be a hard clip and not
>> antialiased?
> 
> I don't think antialiasing of text will ever cause it to extend
> outside a clip that it's in.
> 
>> Because of transition, animations and 3d transform, I don't believe that
>> this will be a temporary solution (unless of course display technology
>> advances so much that subpixel-AA is no longer needed)
> 
> I think in the long run, as display densities increase, we may well
> be moving towards subpixel AA no longer being needed.  But that's
> probably a long ways off.  I don't think your other examples are use
> cases for author control (nor have I heard of such author control
> ever being provided on platforms other than Mac).
> 
> -David
> 
> -- 
> 𝄞   L. David Baron                         http://dbaron.org/   𝄂
> 𝄢   Mozilla                           http://www.mozilla.org/   𝄂
>

Received on Thursday, 18 July 2013 14:18:53 UTC