[racket] Pixel sorting

Hi there list.

I came across this technique:
http://kimasendorf.tumblr.com/post/32936480093/processing-source-code

It was originally implemented in processing, and I thought I'd have a
shot at doing something similar in racket. Here's what I came up with:

https://gist.github.com/minikomi/96776d0bb0dbb05af90c

Check it out and have a play around! Pretty fun to point it at images
on the web.

If anyone can offer ways to speed it up I'm also very open to suggestion.

Also, if anyone is making anything graphics related in racket (image
manipulation, simple animations) I'd like to hear about it. There's a
few people in my office who use open frameworks for such things but I
don't like the C++ style of it at all :)

-A