Edit (Jan 30th, 2017): I written an article on how Random Art works. You can read it here.
Well... actually I ported that to C++ (& Qt) first about a year ago, then I did another port over to C# four months later. The C# one was a little more interesting because it was a distributed rendering system leveraging cloud services and RabbitMQ; I ended up using it on a film I was working on. Pretty cool. Those... I don't really feel comfortable sharing the source to right now. But I'll give you a Nim implementation instead. : P
You can find the application over here on GitLab (or GitHub if you prefer it). To compile the thing, your going to need GLFW installed as well. It can run into two modes: CPU bounding rendering and GPU (via OpenGL). There is a lot more info the in the Readme, but here is the usage message:
Usage: ./random_art [input] [options..] input : a path to an equation file, or provide `stdin` to read input from standard input Options: -r, --renderer : cpu | opengl render on the CPU or with a GPU (using OpenGL) -s, --size : <width>x<height> the dimension of the render, must be a positive int -b, --bounds : <xMin>,<xMax>,<yMin>,<yMax> the bounds to use to render, must be a float -o, --output : <filename>.png the file to save the render as, must end with .png
If you run the application without providing an equation, it will think up one for you. Writing your own equations has this Scheme-like syntax. It's pretty easy to understand, but also to parse. The equation below makes the image to the right.
(mul (var y) (mod (sum (var x) (var y) ) (const 1 0.7 -0.1 0.95) ) )
I plan on working on this some more down the road. You can already see some of my changes showing up (e.g. an alpha value). I'll keep you guys posted. Once again, the code is available here (GitHub mirror).