- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Tue, 24 Jun 2014 14:44:03 -0700
- To: Juergen Roethig <roethig@dhbw-karlsruhe.de>
- Cc: www-svg <www-svg@w3.org>
On Tue, Jun 24, 2014 at 2:27 PM, Juergen Roethig <roethig@dhbw-karlsruhe.de> wrote: > 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 [http://www.w3.org/TR/SVG/coords.html]: >> >> 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. In practice, user-space units and px units are interchangeable. If the spec is unclear, it can be fixed, but what I'm saying is definitely true. Here is a test-case: <!DOCTYPE html> <svg viewBox="0 0 10 10" width=100 height=100 style="border: thin solid;"> <rect x=1 y=1 width=2 height=2 fill=blue ></rect> <rect x=1 y=5 width=2px height=2px fill=green></rect> </svg> Using other units, such as 'em' or 'cm', also makes this clear - they're scaled accordingly to maintain the correct relationship with the px unit. >>> On Tue, Jun 24, 2014 at 12:48 PM, Juergen Roethig >>> <roethig@dhbw-karlsruhe.de> 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! This is getting quite inappropriate. Please stop. ~TJ
Received on Tuesday, 24 June 2014 21:44:51 UTC