- From: Ian Hickson <ian@hixie.ch>
- Date: Fri, 13 May 2011 04:29:05 +0000 (UTC)
On Fri, 13 May 2011, Glenn Maynard wrote: > On Thu, May 12, 2011 at 11:34 PM, Ian Hickson <ian at hixie.ch> wrote: > > > > No, ImageData exposes the underlying data, not the data in CSS pixels. > > I know. That's what I was responding to: having different backing store > dimensions and dimensions exposed by ImageData doesn't make sense. > > If you mean that getImageData might return data of different dimensions > than the canvas coordinate space (which I see the spec allows), that > sounds like it would cause major interop problems if anyone actually did > that. It's very unobvious and I'd expect most people to miss it. It's pretty much the entire point of that API. That's why it has separate height/width information than the canvas. It has to be that way because there's no guarantee that CSS pixels will map to device pixels -- and that's not theoretical, there are shipping devices with high-density screens already (e.g. the iPhone). > Anyway, this doesn't help this case in general anyway because the > full-screen zoom level can change at any time. Sure, but there's not much that can be done for that case. -- Ian Hickson U+1047E )\._.,--....,'``. fL http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Thursday, 12 May 2011 21:29:05 UTC