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

On Mon, Jul 29, 2013 at 1:08 PM, Tab Atkins Jr. <jackalmage@gmail.com>wrote:

> On Mon, Jul 29, 2013 at 12:40 PM, Rik Cabanier <cabanier@gmail.com> wrote:
> > On Mon, Jul 29, 2013 at 4:10 AM, Simon Sapin <simon.sapin@exyr.org>
> wrote:
> >> Le 26/07/2013 18:41, Tab Atkins Jr. a écrit :
> >>> On Fri, Jul 26, 2013 at 10:21 AM, Simon Sapin<simon.sapin@exyr.org>
> >>> 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.
> >
> >
> > It seems that browser zoom/changing the device pixel ratio should not be
> > affected by 'snap'.
>
> They're not affected by snap, but snap is affected by them.
>

That's what I meant :-)
Wouldn't this result in weird resizing behavior while zooming?

For instance, you have a 96x96 pixel image that knows it 96dpi. By default,
it will take up 96 CSS and device pixels on the screen.
If you zoom by 10%, it will still take up 96 CSS pixels but 106 device
pixels.

Now what happens if you set the image style to:

image-resolution: from-image snap;



> > This is a very confusing property. Shouldn't there be a reference to
> device
> > pixel ratio?
>
> Maybe?  The relevant concepts are very ill-defined in the platform at
> the moment (and this is a legacy property).
>

I agree.
What do you mean by 'legacy'? Did anyone implement this?