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Re: [whatwg] High-density canvases

From: Ian Hickson <ian@hixie.ch>
Date: Thu, 12 Sep 2013 17:42:50 +0000 (UTC)
To: Robert O'Callahan <robert@ocallahan.org>
Message-ID: <alpine.DEB.2.00.1309121742300.12210@ps20323.dreamhostps.com>
Cc: Rik Cabanier <cabanier@gmail.com>, Dean Jackson <dino@apple.com>, Stephen White <senorblanco@chromium.org>, WHAT Working Group <whatwg@whatwg.org>
On Thu, 12 Sep 2013, Robert O'Callahan wrote:
> On Wed, Sep 11, 2013 at 11:24 AM, Ian Hickson <ian@hixie.ch> wrote:
> > On Wed, 11 Sep 2013, Robert O'Callahan wrote:
> > > Pinch-zoom is hard because we don't want to trigger reflows or other 
> > > expensive behavior on pinch-zoom. I'd leave pinch-zoom out of it for 
> > > now.
> >
> > Unless I'm missing something fundamental, changing the pixel density 
> > doesn't cause a layout, it's changing the width that causes a layout.
> 
> Changing pixel density does cause a layout in Gecko. For example we 
> round CSS border widths to a whole number of device pixels. (This 
> ensures that when page zoom is applied, all borders with the same 
> specified width are rendered with the same visual width.) On some 
> platforms (Windows), changing pixel density affects text hinting which 
> affects text layout.

So how do you do pinch-zoom under the hood on mobile devices?

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Thursday, 12 September 2013 17:43:16 UTC

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