I have been working since a while ago on a painter algorithm that uses GLSL shaders to handle a particle system in real time. The particles move on the screen, generating an effect that gives the impression of flowing paint. I implemented this algorithm in Processing, and the last week I finally managed to get some time to work on two optimizations to the original version of the algorithm: texture displacement mapping and Vertex Buffer Objects. With these two optimizations, the number of particles that can be displayed at a playable framerate goes from 10,000 up to 100,000. Here is the link.