Games use a fixed-timestep for physics, while allowing the video timestep (fps) to vary. This means your update(delta)
function gets called with a constant delta value. This maintains stability.
This means in practice, update
may end up being called multiple times on average per single call of draw()
, depending on how much time elapses.
For details see: Gaffer’s “fix your timestep”
A larger (python) example is at cookbook: ConstantGametime