It's just a quick project. Pick a few points not too far from the center point and the program will try generating a curve that passes through them. Hold space to pause and see all the waves making up the curve. The random-colored waves and dark grey bars representing the multipliers on the waves are shown to be larger than they should be, so if you actually stacked the waves up, the final result would be stretched vertically.
a long time ago I saw this Fourier transform thing https://en.wikipedia.org/wiki/Square_wave This program just makes small adjustments in the waves rather than trying to solve the system of equations.