[whatwg] High-density canvases

[Boris Zbarsky]

On 9/10/13 4:22 PM, Dean Jackson wrote:
> I think there are two separate things a developer might want:
>
> - the number of actual pixels that correspond to 1 CSS px without zoom

What are the use cases for this, as opposed to "number of actual pixels 
that correspond to 1 CSS px"?

And are you talking about the sort of zoom that changes layout (because 
it changes the number of CSS px per device px and hence changes font 
rasterization), or the sort that does not (which basically does a zoom 
without changing font metrics)?

> - the page zoom

Which one?

> Indeed. I’m not opposed to exposing this. I am reluctant to change something that has behaved a particular way for a number of years.

Shipping UAs already disagree on how devicePixelRatio works with zoom. 
They also disagree on how zoom behaves in general.

-Boris