[mxtopher]

so tick calls requestAnimationFrame that calls tick that... Doesn't it create an ever growing stack? Isn't there a way to do it with a while loop?

[Rusky]

requestAnimationFrame just queues up the callback for later, it doesn't actually call into it. There's no stack growth.

[zerocrates]

It doesn't create an ever-growing stack.

tick calls requestAnimationFrame, tick returns, the browser waits for the next frame and calls tick...