Fourier Epicycles

Drag on the canvas to draw a closed shape (try to finish near where you started), or pick a preset. The path is resampled into points treated as complex numbers, a Discrete Fourier Transform decomposes it into rotating vectors, and the largest N of them — chained tip-to-tail — redraw your outline, leaving a glowing trail that loops each period. Slide Harmonics low for a rough sketch, high for a faithful copy. Works with touch, too.