- From: Ian Hickson <ian@hixie.ch>
- Date: Tue, 8 May 2007 04:57:35 +0000 (UTC)
On Tue, 16 May 2006, Andrew Fedoniouk wrote:
> > > |
> > > | Canvases are automatically double-buffered.
> > >
> > > Why? Is this a requirement?
> >
> > Not in theory, but in practice it is. Early Opera implementations
> > didn't do this and the performance was too slow for practical use.
>
> This does not mean that acceptable implementation without
> double-buffering is not possible or does not make sense.
>
> For simple cases like custom bullet for the list it makes sense to have
> one of these (or combination of these):
>
> 1) non-buffered draw, small area to draw and simple image. If
> buffered draw needed - use Image;
>
> 2) or to have getGraphics defined as
> getGraphics("what",x,y,width, height, backgroundColor = transparent) or
>
> 3) or to be able to say for example
> element.style.listStyleImage = new Image();
>
> 4) or in <style> to define
> li { list-style-image: url("script: nameOfVariableHoldingImage;"); }
>
> (assumption was made that getGraphics/Canvas will be available for any
> element)
I don't really understand. For bullets, <canvas> isn't really the right
answer anyway. The expected use case for <canvas> is graphs, games, that
kind of thing. I also don't see why double buffering would be bad even for
bullets.
--
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Monday, 7 May 2007 21:57:35 UTC