Re: SVG Fonts inside of OpenType fonts? [Cross-post from www-font@w3.org]

Alex Danilo:
> > This is incorrect. If an implementation does SVG Full fonts, then the
> > content can contain <use> elements.

Levantovsky, Vladimir:
> I am not sure what you mean by content. Would plain sequence of
> Unicode codepoints be considered a content?

I think Alex means the content of the <glyph>, i.e. you can have

  <svg …>
    <defs>
      <path id="a" d="M …"/>
    </defs>
    <font>
      <glyph>
        <use xlink:href="#a"/>
        …
      </glyph>
    </font>
  </svg>

> > So, the glyph geometries themselves can just sit in a <defs> or
> > wherever, and you could even use their 'id' as your glyph index.
> > Then the <glyph> elements in the SVG font can reference an arbitrary
> > number of them. i.e. one-to-m, n-to-m and n-to- one mappings are all
> > possible with the SVG font spec. as is, no changes required.
> > 
> > It is a fact that an authoring tool is capable of outputting SVG
> > font outlines for glyphs etc. as a single self contained file with
> > no rendering ambiguity. Furthermore, language dependent rendering
> > can be achieved with <switch> if you wish.
> 
> I am sorry, I don't understand half of the above (I'm sure due to my
> limited knowledge of SVG Full fonts). Maybe a simple use case could
> help illustrate this workflow better:
>
> I have an SVG Full font and a string of Unicode characters that belong
> to a complex script where each character may be represented by one
> of many glyphs available in SVG font, and where a number of various
> character combinations may need to be replaced by a single glyph
> (ligature). I expect to get a readable text displayed as the result.
> What would have to happen for a text to be rendered correctly?

In cases where you have a complex script that isn’t supported directly
by SVG Font’s ligature and Arabic form features, then you can use
<altGlyph> to select an explicit glyph to use for a run of Unicode
characters.  For example:

  <font>
    <glyph id="complex">
      …
    </glyph>
  </font>
  <text>The <altGlyph xlink:href="#complex">xyzzy</altGlyph>
    glyph.</text>

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