This is the visualization of Fourier's series you can play around with. You can:

• Customize radius
• Customize frequency
• Customize phase displacement
• Add more circles
• Observe interesting figures those simple things make

Source code:

https://github.com/GaidamakUA/FourierGodotPlayground

Notes:

• If you can - please don't use web version. It's buggy.
• If web version blinks going fullscreen might fix it for you.
• To customize circle you have to select one at the bottom left.

If you have UI suggestions or know how to make it more user friendly - welcome to comments.