[css-masking] coordinate spaces for clipPathUnits="" and maskUnits="" when targetting non-SVG elements

I think the spec isn’t clear currently about how to interpret x="",
y="", etc. on SVG <clipPath> and <mask> elements when clip-path and mask
properties are used on non-SVG elements.  The sections defining the
clipPathUnits="" and maskUnits="" don’t discuss this, and probably
should mention this case, or link to the existing interpretations of
<geometry-box> for the properties.

Maybe the property definitions should say that fill-box is the default
when it’s not specified (and note that when specifying a <clip-source>
in clip-path, you can’t specify a <geometry-box> at all).  Some text
that says userSpaceOnUse corresponds to a coordinate space where (0,0)
is the top left corner of the <geometry-box> and its width/height are
the size of the <geometry-box> would be good too.

Relatedly, the discussion of the <geometry-box> that can be part of
mask-clip talks about how it defines the area that the “painted content”
is restricted to, but this doesn’t talk about how it should also define
the coordinate space for a referenced SVG <mask> element.

-- 
Cameron McCormack ≝ http://mcc.id.au/

Received on Friday, 6 November 2015 04:15:08 UTC