This is a little physics toy I've been working on off and on for a while. I originally planned on making a more fully featured game of some sort (I suppose I still may some day), but it turns out that writing interesting graphics and physics algorithms is more compelling than the hard work of polishing an actual product. Who knew?<p>While there are plenty of good guides for 2D and 3D graphics and physics, there's not much out there for 4D. In hopes of alleviating that, the code here is arranged such that the commits are more or less a step-by-step guide, with comments for the interesting or tricky parts. While I don't think I came close to the simplicity or clarity of Box2D Lite, I hope it can serve as a useful example to anyone interested in 4D rendering and physics.