default viewport size of SVG resource documents

Is it defined what the default size of an SVG resource document is?  I
don’t think it is, and we probably should define it.

I am not sure whether it is possible to write content that depends on
this size in regular SVG documents (if you think of a way, let me
know!), but I think it is possible with SVG glyphs in OpenType.  For
example, if the font document is:

  <svg xmlns="">
    <rect glyphid="1" width="100%" height="20"/>

this would define a glyph consisting of a rectangle that hangs just
below the baseline at a height of 20 units-per-em.  It’s not clear what
the 100% would resolve against, though.  In a regular SVG document that
is being presented in some viewport then that viewport size will
determine the viewBox automatically.

For font documents, I think it could make sense to define the viewport
as a square whose width and height are the units-per-em value from the
font’s head table.  More sense than any other values, probably.

Cameron McCormack ≝

Received on Thursday, 12 March 2015 06:08:46 UTC