Web Audio API visualizer: LED spectrum and dynamic gradient

An LED-looking spectrum visualization as well as color gradient that isn't just a horizontal or vertical gradient.

Settings used:
* FFT size: 9600 samples (exactly 200ms on 48kHz sample rate, non-power of two FFT size supported by my custom FFT routine that WebAudio's built-in analyzer doesn't support)
* Window function: Gaussian w/ parameter of 2.4 (similar to foobar2000's built-in windowed FFT visualization for use with visualization components)
* Color: Scaled gradient (similar to Vertical C option in foo_musical_spectrum)
* Peak decay rate: 0.025 w/ 0 frames delay
* Main bay decay: Similar to spectrum analyzer thing in FabFilter Pro-Q 3 (w/ smoothing time constant of 95%)
* Bands per octave: 1/24th octave (240 bands on 20Hz-20kHz range)

This project: Frequency bands spectrum analyzer using either FFT or CQT (https://codepen.io/TF3RDL/pen/poQJwRW)
Song: Xtrullor - Neophyte (https://www.youtube.com/watch?v=5FXJ6Tqygj4)

BTW, I've made a new (unlisted) playlist of what soundtracks would be included in a hypothetical billiard simulation game "SM Billiards" (basically ShootersPool but without real-world brands, lots of game modes like Russian Pyramid and Snooker Plus, and of course console versions): https://www.youtube.com/playlist?list=PLLJN6ybTUJL61XJy24yBz_mkZeosEINkf

Видео Web Audio API visualizer: LED spectrum and dynamic gradient канала Andri Gunawan