Question

In my game engine, there are objects that need to be updated periodically. For example, a scene can be lowering its alpha, so I set an interval that does it. Also, the camera sometimes needs to jiggle a bit, which requires interpolation on the rotation property.

I see that there are two ways of dealing with these problems:

1. Have an update() method that calls all other object’s update methods. The objects track time since they were last updated and act accordingly.

2. Do a setInterval for each object’s update method.

What is the best solution, and why?

Answer 1

setInterval does not keep to a clock, it just sequences events as they come in. Browsers tend to keep at least some minor amount of time between events. So if you have 10 events that all need to fire after 100ms you’ll likely see the last event fire well into the 200ms. (This is easy enough to test).

Having only one event (and calling update on all objects) is in this sense better than having each object set it’s own interval. There may be other considerations though but for at least this reason option 2 is unfeasible.

Here is some more about setInterval How do browsers determine what time setInterval should use?