I was working on a Unity project and came across an example where the input manager sets a public variable, like 'jump', to true when a key, such as the spacebar, is pressed. The character then checks this variable every frame to determine if it should jump. My main questions are: 1) Isn't it more efficient to use a callback method like 'ExecuteJump' to handle this instead of polling a variable? Why would the Unity development team choose this method? 2) Are there scenarios where polling is genuinely better for performance compared to callbacks, or does it have advantages that callbacks don't? 3) While I find polling can complicate debugging, could implementing a design pattern like the observer pattern simplify this while maintaining efficiency?
3 Answers
Not everything needs to prioritize efficiency; simplicity often pays off in the long run. Establishing a clear and predictable flow can help prevent issues that arise from state complexity and potential race conditions. Sometimes, easier code leads to better maintainability.
In the context of Unity's frame-based update system, polling fits perfectly. Most gameplay systems run every frame, so checking the input state during that time keeps timing predictable and efficient. A few boolean checks aren't costly performance-wise. While callbacks are useful for one-time events, they can mess with the order of operations if they trigger at the wrong time.
Polling is often simpler because you can easily control when and how often it happens. For example, if you're polling every update, you know exactly when that check occurs. With callbacks, things can get unpredictable, especially if the state changes rapidly or multiple actions trigger the same callback. Plus, if you're dealing with complex states, a centralized polling approach can be much cheaper than having several callbacks checking against multiple conditions every frame.
Thanks for the insight! It really clarifies why polling can be a good choice.
Exactly! Focusing too much on efficiency can complicate things unnecessarily.