Re: transform as a presentation attribute [was: Re: [whatwg] SVG cloning elements from HTML5]

Hello world,

Tab Atkins Jr. wrote:
> So, all "transform" does is transform the coordinate space that those
> units work in.  This is identical between CSS and SVG; some SVG
> presentation attributes just allow px lengths to be specified without
> a unit, while the CSS properties require units.  So yes, your
> coordinate system unit might be 5px wide *in the untransformed
> viewport's coordinate space*, but in the local space it's still just
> 1px, because user coordinates *are* px units when untransformed.
> Viewbox is a scale/translate transform applied after the other
> transforms.

The statement "user coordinates *are* px units when untransformed" is 
_not_ true, at least not for SVG in the actual specification.
See []:
> Lengths in SVG can be specified as:
> (if no unit identifier is provided) values in user space — for example, "15"
> (if a unit identifier is provided) a length expressed as an absolute or relative unit measure — for example, "15mm" or "5em"
> The supported length unit identifiers are: em, ex, px, pt, pc, cm, mm, in, and percentages.

This is a clear distinction between values in user space and a length 
expressed with the help of a unit. And besides that, a px unit even in 
mobile "devices" has some relationship with a "device pixel" - the 
device has just a "virtual resolution" of, say, 320px*480px, since the 
first such devices had that measure as physical resolution, and nowadays 
the resolution is somewhat higher. And because some web pages for such 
mobile devices were designed by people who did not understand the 
difference between a user coordinate system and a physical length, those 
browsers were stuck to a "virtual resolution" of 320px*480px. But when 
someone comes up and says that my device might now even have a 
resolution of 0.04px*0.06px, I will doubt about his soundness of mind 
... and if the unit is so unimportant in those cases, why don't we call 
a "px" a rabbit, and a "in" a "hedgehog", from now on? It's just a 

>> On Tue, Jun 24, 2014 at 12:48 PM, Juergen Roethig
>> <> wrote:
>> ... but I am surprised to learn, just now, about the accuracy, carefulness,
>> and reliability when making new "standards" in the W3C - so far the "living
>> standard" of HTML was the best example for that (and yes, I know, the term
>> "living standard" for HTML is not originating from the W3C), but other
>> standards seem to adopt those superiour principles as well (irony intended,
>> or in that case you might even call it sarcasm).
> Cool story bro.

Not as cool as the "Junior" on this list!

Juergen Roethig

Received on Tuesday, 24 June 2014 21:29:08 UTC