What he means is that stuff that runs a lot of times per second (based on frame/tick) should have the variables already created, cause this process is kinda expensive when running loops/lot of times.
Is better to use variables that you already have the value like "which button" is being pressed, before, when possible, than all that calculations logic.
Also, you shouldn't do a lot of calculations inside this process cause will hang
A good use case would be putting all that inside a timer, so instead of calling 1280 times per second you could optimize it to running, for example, once per second.
He also said that timer wouldn’t be good because it would not be accurate for simulating a tickrate
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