Re: transform as a presentation attribute

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

Received on Wednesday, 25 June 2014 21:32:59 UTC