On 11 Sep 2013, at 5:32 am, Ian Hickson <i...@hixie.ch> wrote: > On Wed, 11 Sep 2013, Dean Jackson wrote: >> On 11 Sep 2013, at 12:14 am, Stephen White <senorbla...@chromium.org> >> wrote: >>> >>> now that some browsers are including browser zoom (page zoom) in >>> window.devicePixelRatio >> >> Ouch. Who is doing this and why? > > Why ouch?
Because we’ve always operated under the assumption that devicePixelRatio is the mapping from CSS px to device pixels at 1:1 scale/zoom, and that it is constant for a particular display. The only change content would see is if the window is dragged to/from a high resolution screen. There are other ways to query the page zoom. I fear this will break existing content. I don’t think we’d ever want to change the behaviour. Dean > > Actually what I really think we should do is also change the > window.devicePixelRatio for pinch zoom. Combined with the suggestions for > canvas, that would allow (as Rik pointed out on IRC) for high-quality > canvas all the way zoomed in, and for cheap canvases when zoomed out.