Re: transform as a presentation attribute

Tab Atkins Jr.
>However, there is absolutely nothing wrong with a UA choosing instead
>to set a px to 1/96th of an actual inch, so that all the physical
>units are physically correct, if it has the information to do so.

But they don't . And probably won't ever - unless there was specific
mechanism to do so.  If renders were expected to support that then
physical/absolute units will actually become a lot more useful.  It would
open up whole new use cases for SVG..

Paul






On 26 June 2014 09:32, Tab Atkins Jr. <jackalmage@gmail.com> wrote:

> On Wed, Jun 25, 2014 at 6:16 AM, Paul LeBeau <paul.lebeau@gmail.com>
> wrote:
> >> Presumably SVG 2 will adopt this from CSS 2.1, this will apply as well.
> >
> > Has there been any discussion on adding an ability to alter the default
> DPI?
>
> This is up to the browser.  Olaf's statement is unfortunately slightly
> incorrect, in a rather common way.  What CSS did was fix the ratio
> between the px unit and the other absolute units, effectively
> transforming px into an absolute unit just like pt is.  However, it
> *also* explicitly allows user agents to vary their definition of
> absolute units in order to make the px unit fit a more convenient
> size.  On laptops and desktops, this is usually done to make the px an
> exact multiple of the device pixel size, but on many mobile devices,
> it's instead used to make the screen exactly 320px wide, for better
> compat with pages designed solely for the iPhone.
>
> However, there is absolutely nothing wrong with a UA choosing instead
> to set a px to 1/96th of an actual inch, so that all the physical
> units are physically correct, if it has the information to do so.  The
> spec even explicitly recommends doing so for printing, where the
> arguments for an altered px value are much weaker.
>
> We do not yet have anything that lets an author explicitly request a
> particular unit scale.
>
> ~TJ
>