On Friday, March 21, 2008, 9:49:07 PM, Krzysztof wrote:
KK> Felipe Sanches wrote:
> SVG1.1 spec, on session 20:
> The purpose of SVG fonts is to allow for delivery of glyph
>> display-only environments. SVG fonts that accompany Web pages must be
>> supported only in browsing and viewing situations. Graphics editing
>> applications or file translation tools must not attempt to convert SVG
>> into system fonts. The intent is that SVG files be interchangeable
>> two content creators, but not the SVG fonts that might accompany these
>> files. *Instead, each content creator will need to license the given font
>> before being able to successfully edit the SVG file.* The
>> indicates the name of licensed font to use for editing.
> Am I getting confused or is this part of the spec really
promoting the use
> of DRM techniques for SVG Fonts?
KK> I think it means that:
KK> 1. SVG fonts are used to enable rendering of SVG images that contain a font
KK> that isn't on your system.
KK> 2. Because some fonts are copyrighted, if you have licensed i.e. a TTF font,
KK> you should be able to convert it into an SVG font to allow other people to
KK> see it on your web page, however others should not be able to take your
KK> generated SVG font and recreate your licensed TTF font from it.
KK> 3. I also think it means that editing an SVG image that contains SVG fonts
KK> created from licensed fonts should be impossible unless the original TTF
KK> font is present in your system.
It could be read that way. That isn't the intent. For one thing, there might not be an
'original' font in a different format.
KK> 4. Because the SVG font has the full information required to display a
KK> glyph, it means that respecting those restrictions is up to the goodwill of
KK> I think this basically means that if an SVG font was created from a licensed
KK> font, it's supposed to be "read-only", as well as any document that
not exactly read-only. Editing of the SVG file is fine. SVG fonts are not however
particularly suitable to be converted to system (truetype) fonts, for a number of
- truetype has restrictions on the type of bezier curves allowed, the placement of control
points, and the intersection of curves. SVG fonts need not follow any of these
restrictions, they are general SVG paths.
- truetype depends on (non-royalty free) hinting programs for high quality display of
small, high contrast, axis-aligned text. SVG does not have font hints - svg text can be
displayed at angles, skewed, in multiple colors, at sizes that are not integral multiples
of one pixel and in positions that are not axis aligned or pixel-grid aligned.
KK> and converting such an SVG font to a system-readable font should be
KK> impossible. I have the impression that this paragraph was put in to appease
KK> font vendors (keep in mind that this spec was originally created by Adobe).
The spec was not "originally created by Adobe".
The editor of the 1.0 spec, and one of the editors of the 1.1 spec, was from Adobe. The
list of authors can be seen in the spec and is rather extensive. A lot of different
companies and individuals contributed to the creation of the SVG spec.
KK> It doesn't advocate DRM in its regular sense, rather something like a
KK> "please do not steal" sign.
KK> I think that an SVG font to TTF converter could
KK> comply with this part of the specification, provided it refused to work on
KK> SVG fonts derived from copyrighted fonts.
How would it know? The license info is not machine readable. A person has to make the
Chris Lilley mailto:chris@...157...
Interaction Domain Leader
W3C Graphics Activity Lead
Co-Chair, W3C Hypertext CG