W3C home > Mailing lists > Public > www-svg@w3.org > January 2013

Re: SVG 2 Features and Approach

From: Robert O'Callahan <robert@ocallahan.org>
Date: Fri, 18 Jan 2013 22:43:25 +1300
Message-ID: <CAOp6jLYSjSwnrrJqyNgTaoaAzYm6hu4mUtfnYZSBLyuu9haM=w@mail.gmail.com>
To: Erik Dahlstrom <ed@opera.com>
Cc: "Tab Atkins Jr." <jackalmage@gmail.com>, Doug Schepers <schepers@w3.org>, Charles Lamont <charles@gateho.gotadsl.co.uk>, www-svg <www-svg@w3.org>
On Tue, Jan 15, 2013 at 5:17 AM, Erik Dahlstrom <ed@opera.com> wrote:

> It's more a lack of data tables, for complex shaping and so on. It's
> entirely possible to represent these in XML, but no one seems interested
> enough to do this. OTOH the svg-in-opentype idea suffers from much the same
> problems that SVG Full Fonts have, in the sense that they too need
> restrictions and custom rules (a spec in other words). You'd get more for
> free by representing the necessary OpenType tables in SVG Fonts rather than
> the other way around.
>

I don't agree.

In our experimental implementation, we get "for free" all OpenType shaping
features --- kerning, ligatures, complex scripts, variant glyphs, etc etc.
We didn't have to write a spec for how to express those in XML and map
between Opentype tables and XML, nor did we have to implement such a
mapping, nor did we have to worry about what happens when those
hypothetical XML values are mutated by script, etc. There was literally no
work to do. Of course, CSS features that influence shaping, such as
"font-feature-settings" also "just work".

We took a very simple approach to defining the restrictions on what can be
in an SVG glyph document: we apply exactly the same restrictions as we
apply to SVG images. The only feature of SVG images that you can't use in
SVG glyphs in our builds is animation --- there's nothing difficult about
fixing that, it's just a little more implementation work. Anyway, last I
checked, browsers supporting SVG Fonts supported nothing but single
monochrome paths, which suggests that they aren't using their normal SVG
rendering code to render SVG glyphs. We do.

And you lose a lot of flexibility by going down the svg-in-opentype route
> IMHO.
>

What flexibility are you thinking of?

Rob
-- 
Jesus called them together and said, “You know that the rulers of the
Gentiles lord it over them, and their high officials exercise authority
over them. Not so with you. Instead, whoever wants to become great among
you must be your servant, and whoever wants to be first must be your
slave — just
as the Son of Man did not come to be served, but to serve, and to give his
life as a ransom for many.” [Matthew 20:25-28]
Received on Friday, 18 January 2013 09:43:53 GMT

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