Does anyone know how to make a timer with a time interval of 0.001? I read somewhere that a Timer can't have a time interval lower than 0.02, and my timer is behaving that way.
My timer:
timer = Timer.scheduledTimer(timeInterval: 0.001, target: self, selector: #selector(self.updateTimer), userInfo: nil, repeats: true)
@objc func updateTimer() {
miliseconds += 0.001
}
Yes, you can have time intervals less than 0.02 seconds. E.g. 0.01 second interval is easily accomplished. But at 0.001 or 0.0001 seconds, you’re starting to be constrained by practical considerations of how much you could accomplish in that period of time.
But if your goal is to represent something in the UI, there’s rarely any point for exceeding the device’s maximum frames per second (usually 60 fps). If the screen can only be updated every 60th of a second, what’s the point in calculating more frequently than that? That’s just wasted CPU cycles. By the way, if we were trying to achieve optimal screen refresh rates, we’d use CADisplayLink, not Timer. It works just like a timer, but is optimally timed for refreshing the screen at its optimal rate.
For what it’s worth, the idea of updating milliseconds to capture elapsed time is a bit of non-starter. We never update a “elapsed time counter” like this, because even in the best case scenarios, the frequency is not guaranteed. (And because of limitations in binary representations of fractional decimal values, we rarely want to be adding up floating point values like this, either.)
Instead, if we want to have the fastest possible updates in our UI, we’d save the start time, start a CADisplayLink, and every time the timer handler is called, calculate the elapsed time as the difference between current time and the start time.
Now, if you really needed a very precise timer, it can be done, but you should see Technical Note TN2169, which shows how to create high precision timer. But this is more of an edge-case scenario.