[webfonts] pixel-perfection

It seems we have some work left in order to achieve pixel-perfection
for webfonts. Consider this simple test page:

   http://people.opera.com/howcome/2008/tests/webfonts.html

Which is rendered this way in Safari (3.1.2), Firefox (Minefield 3.1b1
pre 20080911023329) and Opera (internal build):

   http://people.opera.com/howcome/2008/tests/webfonts.png

There are several noteworthy differences:

 - Safari put the first font (Starburst) at the top of the line box,
   Firefox and Opera puts it at the bottom. The small line-height (1)
   accentuates the differences, but it would be interestesting to know
   why the same font is treated so differently. 

 - The second font (Decorated Roman Initials) placed differently in
   all three browsers, although the differences are smaller.

 - Safari's rendering is noticably darker, especially for the ornate
   Decorated Roman Initials. This may be due to it anti-aliasing stratgy?

 - Opera sometimes go below the line box. This is probably a rounding
   error somewhere.

This behavior is outside the jurisdiction of CSS, but for the sake of
authors it would be good to align implementations as much as possible
before webfonts are used for real.

-h&kon
              Håkon Wium Lie                          CTO °þe®ª
howcome@opera.com                  http://people.opera.com/howcome

Received on Saturday, 1 November 2008 23:19:25 UTC