On Thursday, March 20, 2008, 5:55:19 AM, Felipe wrote:


>

SVG1.1 spec, on session 20:


The purpose of SVG fonts is to allow for delivery of glyph outlines in 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 fonts into system fonts. The intent is that SVG files be interchangeable between two content creators, but not the SVG fonts that might accompany these SVG files. Instead, each content creator will need to license the given font before being able to successfully edit the SVG file. The font-face-name element 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?




DRM is an enforcement mechanism. SVG doesn't have one. 


In the early days of SVG, many fonts were produced by conversion from TrueType. There was a concern that if an authoring tool performed the reverse conversion, it could be seen as a way to steal truetype fonts. In practice, since SVG does not do font hinting (truetype hints are programs and can be copyrighted; Type 1-style hints are declarative, and were considered for SVG, but such hinting is hard to specify conformance-wise) this turned out not to be a problem.


The intent of the bolded text was for authoring; if the 'original' font was available, an authoring tool might use that information. For example, if the SVG file had a font with the glyphs S, V and G but the content creator wanted to have text that said 'SAG'; that would require going back to the original font to get the 'A" glyph.


However, its perfectly possible to create an SVG font from scratch (eg, in FontForge). Also, some font licenses let you edit the font and convert to other formats, as long as you don't keep the original name (Bitstream Vera springs to mind). So that text has some issues.


The SVG 1.2 spec says, instead


  

The purpose of SVG fonts is to allow for delivery of glyph outlines in 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 fonts into system fonts. 

http://www.w3.org/TR/SVGMobile12/fonts.html#SVGFontsOverview



which is clearer, and avoids and hand-wavy hints about sneaking in the name of some 'original' font and doing clever things with it on the fly.


As to fonts having licenses, I hope that is not a surprise to anyone. Licenses vary widely in what they allow or disallow. A content designer is responsible for checking that any derived works they make from someone else's content meets any licenses that apply. This is true for fonts, images, sounds, video and so forth. There are several free font licenses available, for example.


A corollary of that statement about it being the content creators responsibility is that SVG implementations will *not* check; there is no DRM in SVG. The renderer takes no position on the legality of the curves in your file :)



-- 

 Chris Lilley                    mailto:chris@...157...

 Interaction Domain Leader

 W3C Graphics Activity Lead

 Co-Chair, W3C Hypertext CG