Drealmer's Tumblr

Visual Studio 2010 does it wrong

ClearType is an anti-aliased font rendering technique used by Windows, for some more information about how it works, have a look at my previous post on the topic: (link). This thing is a matter of taste, you either love it or hate it. I love it.

Recently, my boss told me he could not stand the font rendering in the beta of Visual Studio 2010 (link) because it was blurry. At first I thought it was simply because he was not accustomed to ClearType, but he then told me it was an acknowledged bug (link)… Uh wait, what?

Let’s compare Visual Studio 2008 and Visual Studio 2010 beta, both with Courier New 10, here are the results:

What happened? Why is the 2010 line shorter? Don’t you feel there is something fuzzy on the lower line but cannot point out what? It all becomes clear if we compare a repetition of the same letter and zoom a bit (2008 above, 2010 below):

Because the way sub-pixel anti-aliasing works, twice the same symbol might produce different colors if they are not horizontally aligned on pixels. ClearType is supposed to work this way (snap glyphs), but it looks like WPF (link) got it wrong, and Visual Studio 2010 relies on WPF…