W3C home > Mailing lists > Public > www-svg@w3.org > March 2011

Re: font formats and SVG2

From: John Daggett <jdaggett@mozilla.com>
Date: Wed, 2 Mar 2011 18:23:10 -0800 (PST)
To: "Dr. Olaf Hoffmann" <Dr.O.Hoffmann@gmx.de>
Cc: www-svg@w3.org
Message-ID: <1950846564.494829.1299118990877.JavaMail.root@cm-mail03.mozilla.org>
Dr. Olaf Hoffmann wrote:

>>Can someone explain what the features are that are not offered
>>in TrueType fonts?
> 
> I think, the possibility to embed SVG fonts within a graphics
> (SVG document) is an important feature for authors, as soon as
> this is widely implemented. The glyphs can be created with
> features from SVG, no need to learn yet another format not much
> related to the graphical problem, the authors has, if just a
> few glyphs are needed for a logo or something like that. SVG
> fonts help to keep things simple for authors, especially for
> those not very interested in creating complete fonts for
> general use, but just some glyphs for a special purpose.

Taking SVG-defined outlines and generating a font via FontForge
is a *trivial* process.  Converting these to OpenType allows them
to be used as input to *text* rasterizers (e.g. DirectWrite,
FreeType, ATS) as opposed to purely graphic renderers.
Without the use of a text rasterizer, the results will not be
subpixel antialiased, which typically includes rasterization
techniques tuned specifically for text.

> If the glyph information is directly embedded in the SVG
> document, it is simply possible to provide standalone documents
> with predictable behaviour for the presentation of the glyphs.
> To assume that referenced external fonts in another format are
> always available is risky and I think it will not be acceptable
> for some designers with a quite detailed opinion about the
> appearance of their graphics and how to control this on their
> own.

By this argument, SVG should define a raster graphic element so that
images do not need to be referenced externally.

> A detailed control about the appearance of a glyph it typically
> not so important for the author of such text documents as for
> some text within an SVG document with close relation to other
> graphical content.

What detailed control are you thinking about here, specifically
in the context of SVG 1.2T Fonts?

I think it would be far better to consider ways to better
integrate OpenType fonts in SVG, such as providing API's to
access glyph path data in OpenType fonts.  I think this would
open up a *far* wider set of use cases for authors who want to
modify glyphs from a given font as part of a design than the one
you're suggesting.

One underlying argument I keep hearing is that SVG Fonts provide
an "all-SVG" workflow.  That might be useful in the context of an
SVG-only renderer but as part of an integrated web platform for
graphics, it's redundant.

I think it's best that SVG2 remove SVG font objects entirely. The
use cases just aren't strong enough to justify the ongoing cost
of implementation/testing this mostly redundant feature.

John Daggett
Received on Thursday, 3 March 2011 02:23:44 GMT

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