Re: font formats and SVG2

2011/3/3 John Daggett <jdaggett@mozilla.com>

> 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.


Depend for whom. Triviality, as intuitivity, as simplicity is a matter of
perception and depend a lot of the user. For example, I'm familiar both with
SVG and FontForge. Definitely I found SVG authoring tool much more friendly
and therefor easier to use than FontForge. But I'm sure there is people that
think the opposite.


> 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.
>

SVG fonts and OpenType fonts do not achieve the same purpose. OpenType fonts
are mainly made for regular text where rasterization is important. SVG fonts
are made for graphical use such as ornamental fonts or "glyphs as image" use
case (in logos for example to keep the semantic of each glyph but used in a
highly graphical environment). So if SVG fonts cannot used resterizers is
not such a problem. This is just something authors have to be aware of to
avoid misplaced usage (Yes, I know, most of the time author sucks with
technologies and use them badly... I know, I'm one of them :p ).


>
> > 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.
>

We are talking about fonts, not about raster graphic in general. An author
that want to be in control of it's design do not necessarily want (nor even
need) to relay on rester graphic but if he wants to use fonts at the moment,
you let him no choice.


>
> > 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?
>

Ah ! If you restrict the subject to SVG 1.2T of course the discussion will
turn short.
But with SVG Full it's another story : color, gradient, clipping, filters...
everything that made SVG awesome could be bound with a glyph semantic which
is good for graphical creativity, new usage, and accessibility (that last
point is the most important IMO).

But just with SVG 1.2T fonts and scripting (and maybe some days SVG
parameters) it's possible to design very specific behavior for the font in a
specific graphical environment. This gives the authors higly customizable
graphical 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.
>

This is interesting but not necessarily accurate. Do you seriously consider
that font companies will accept such a feature for OpenType fonts? This is
possible but I seriously doubt it and it will take years (or even decade)
before that happen (but this is something that should be discuss at the W3C
Font WG for WOFF). On the other hand, SVG fonts are here now (incompletely
implemented but here)


>
> 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 agree that there is overlap between SVG fonts and other fonts format but
once again, SVG fonts main purpose is NOT plain HTML text. There are
specific usage and opportunity for SVG fonts in Web design. At the moment we
are in the chicken and egg paradox. It's hard to figure what will happen
with SVG fonts because there is no good implementation available so no one
use SVG fonts at their full potential so no one want to invest in that
technology... sad, really sad for authors and the Web in general.

-- 
Jeremie
.............................
Web : http://jeremie.patonnier.net
Twitter : @JeremiePat <http://twitter.com/JeremiePat>