Re: [css3-images] `image-resolution: span` and transformations.

On Mon, Jul 29, 2013 at 4:10 AM, Simon Sapin <> wrote:
> Le 26/07/2013 18:41, Tab Atkins Jr. a écrit :
>> On Fri, Jul 26, 2013 at 10:21 AM, Simon Sapin<>
>> wrote:
>>> Le 26/07/2013 17:56, Tab Atkins Jr. a écrit :
>>>> I don't think it should.  For one, this would mean that the intrinsic
>>>> size of an image changes as you transform it, which is clearly not a
>>>> good result.
>>> Your first point also applies to user zoom, especially with mobile-style
>>> panning zoom. What does "snap" mean in this context?
>> No, mobile pinch-zoom is a distinct type of zoom.  We need to
>> formalize these concepts within CSS, as they're being formalized in
>> the back-end ad-hocly right now.
>> The relevant type of zoom is the one that changes the viewport size.
>> This changes a bunch of the layout, so it's okay for images to have a
>> different intrinsic size.
> Ok. So, to sum up:
> * Transforms should not affect 'snap'. This makes 'snap' useless on
> transformed images, but that seems better than the alternative.
> * "Desktop-type" zoom that changes the size (in CSS units) of the initial
> containing block should affect 'snap'. That’s fine because layout probably
> changes anyway.
> * "Mobile-type" zoom that does not change the size of the ICB should not
> affect 'snap'. IMO this makes 'snap' completely useless if the user is
> expected change the zoom level a lot. I’d rather have UAs ignore it in such
> cases than apply it in a way that only makes sense at one precise zoom
> level.

If you're designing a mobile site and care about the resolution of
your images, you should be setting the zoom level to 1 anyway.  Users
are *not* generally "expected to change the zoom level a lot" - when
that's happening, it's because they're using a site designed solely
for desktop without any thought given to mobile.

Additionally, as I stated, these constraints are exactly the same as
what we want to expose for <canvas>.


Received on Monday, 29 July 2013 16:34:23 UTC