referencing SVG Integration specification for SVG glyph requirements

[Cameron McCormack]

The SVG Working Group feels it would be better for the OpenType spec to
move some of the requirements on how SVG glyph documents are handled
to the SVG Integration spec.  SVG Integration (which is published at the
W3C) defines requirements on how SVG documents are processed in the
context of other documents.  We already have a normative dependency on
SVG Integration for “secure animated mode”, which is what requires that
script does not run, animations do run, interaction is not possible, and
external references are disallowed.

The specific requirements that I think should be moved to SVG
Integration are:

  1. The user agent style sheet rule that sets ‘fill: context-fill’
     etc. on the root element.

  2. The user agent style sheet rule that disables rendering of
     <text> and <foreignObject> elements.

The requirement to add user agent style sheet rules to map the palette
colours to CSS custom properties can remain, as they have a much
stronger dependency on exactly how the palette is defined in the font.

Doing this will let us update the requirements as new SVG features are
introduced, as I believe W3C specifications can be updated more quickly
than OpenType, and in tandem with any new SVG specifications (such as
SVG 2, which is in development now).

The SVG Working Group discussed this at our face-to-face meeting last
week and resolved to publish a Working Draft of SVG Integration (it
previously existed only as an Editor’s Draft) incorporating the above
changes.  This is now available here:

  http://www.w3.org/TR/svg-integration/

That undated URL is what should be referenced from OpenType, so that it
will always point to latest published version of the document.

I have wrapped up the “secure animated mode” requirement and the above
two user agent style sheet rules into a single referencing mode named
“font document”, which is what the reference to “secure animated mode”
should be replaced with.

Thanks,

Cameron

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