06:26 pm, 9 Apr 09
opentype condom
http://github.com/agl/otc/tree/master:
The CSS font-face property is great for web typography. Having to use images in order to get the correct typeface is a great sadness; one should be able to use vectors.See also my discussion of the terror of web fonts.
However, the TrueType renderers on many platforms have never been part of the attack surface before and putting them on the front line is a scary proposition. Esp on platforms like Windows where it's a closed-source blob running with high privilege.
Thus, the OpenType Condom (OTC) is designed to parse and serialise OpenType files, validating them and sanitising them as it goes. Most significantly, it removes hinting bytes from the files as it processes.
The name is also pretty bad, and reeks of just wanting to use "condom" in a name. Based on the name, I assumed it insulated the font renderer completely, but in fact it filters out bad and passes through good - this is almost exactly *not* what condoms do.
Interesting...
It's a shame it can't also sanitize rather than strip the bytecode bits, since many fonts look terrible without hints.
However, I guess doing foolproof sanitizing would involve the halting problem and other such trouble, plus they'd probably fall foul of the patents on the TrueType hinting language.
(For Chromium, we don't use the X server's font rendering so we side-step it anyway.)
However, you're certainly right that an X client can change the server's font path. That's why we don't allow the renderer process to have an X connection (among many scary reasons).
Cheers
Alternately useful
As a code monkey for a large corporate entity, one of my concerns for using web fonts is the potential for a legal smackdown that comes from using TTFs of client-requested, usually non-distribution licensed fonts.One of the nifty legal loopholes in typographic IP law is that the glyphs are not protected by anything - but the hinting code is. Therefore, it's an infringement of copyright to use a hinted TTF file on a webpage, as you're implicitly distributing hinting code to the entire world.
This is why sIFR, for example, is completely legal: Flash only embeds the glyph code; it figures out how best to render the results by itself, without the hinting code.
Fonts without hinting no longer look as bad as they used to; higher resolution displays and ubiquitous sub-pixel hinting (effectively bumping up the horizontal resolution by a factor of three) have pretty much rendered the presence of hinting code a non-issue.
Now if only I could get this (otc) built*, I could provide a web service to do the heavy lifting for everyone (I've already got a TTF->EOT (IE4+) and TTF->SVG (Safari 2+) converter; stripping out the hinting data would be the last necessary item to have broad support (Fx 3+ supports TTF, but not SVG).
* Unfortunately, Dreamhost has no support for scons, so I've got to put together a Makefile if I'm to get it working.