Possible algorithm suggestion

I just saw part of the video on twitch. Since i am not familiar with processing, i am using this issue to give a possible solution.

First i will assume that correct maths are not necessary to avoid overcomplexity. Given that, i will use this [math.stackexchange](https://math.stackexchange.com/a/2145870/580045) answer as a base.
From it

we can derive a new equation for R = ± sqrt((L t)/π + r^2) and t!=0 for the external radius.

Second we understand that in a tape recorder, it is the reading head that drives the tape

Given that, we could have:
- constant max tape length: L
- variable tape length of the left supply reel : L1
- variable tape length of the left supply reel : L2
- constant tape thickness: th
- conversion equation: R = ± sqrt((L th)/π + r^2)
- the head: loop/stream
- returning a certain amount of length by time
- or just directly changing L1 and L2
- left supply reel:
- taking the stream of length and using the conversion equation to create new circles of stroke th
- or just do it directly depending on L1
- right take-up reel: subtracting the stream of length and doing the reverse from the supply reel.

The exact code will depend highly on the capabilities of the processing language...