Publisher-Subscriber pattern C# delegates and events
When events can be based on visibility, distance, or collisions, we can use such events as OnTriggerExit and OnBecomeInvisible. When events can be based on time periods, we can use coroutines. However, some events are unique to each game situation, and C# offers several methods of broadcasting user-defined event messages to scripted objects. One approach is the SendMessage(...) method, which, when sent to a GameObject, will check every Monobehaviour scripted component and execute the named method if its parameters match. However, this involves an inefficient technique known as reflection. C# offers another event message approach known as delegates and events, which we describe and implement in this recipe.
Delegates and events work in a similar way to SendMessage(...), but are much more efficient since Unity maintains a defined list of which objects are listening to the broadcast events. SendMessage(...) should be avoided if performance...
