IEnumerator WaitForPreviousTransition(FiniteStateMapping nextState)
{
while (isInTransition)
{
yield return(null);
}
ChangeState((T)nextState.state);
}
private IEnumerator ChangeToNewStateRoutine(FiniteStateMapping newState, FiniteStateTransition transition)
{
destinationState = newState; //Chache this so that we can overwrite it and hijack a transition
if (currentState != null)
{
if (currentState.hasExitRoutine)
{
exitRoutine = currentState.ExitRoutine();
if (exitRoutine != null && transition != FiniteStateTransition.Overwrite) //Don't wait for exit if we are overwriting
{
yield return(engine.StartCoroutine(exitRoutine));
}
exitRoutine = null;
}
else
{
currentState.ExitCall();
}
currentState.Finally();
}
lastState = currentState;
currentState = destinationState;
if (currentState != null)
{
if (currentState.hasEnterRoutine)
{
enterRoutine = currentState.EnterRoutine();
if (enterRoutine != null)
{
yield return(engine.StartCoroutine(enterRoutine));
}
enterRoutine = null;
}
else
{
currentState.EnterCall();
}
//Broadcast change only after enter transition has begun.
if (Changed != null)
{
Changed((T)currentState.state);
}
}
isInTransition = false;
}
public FiniteStateMachine(FiniteStateMachineRunner engine, MonoBehaviour component)
{
this.engine = engine;
this.component = component;
//Define States
var values = Enum.GetValues(typeof(T));
if (values.Length < 1)
{
throw new ArgumentException("Enum provided to Initialize must have at least 1 visible definition");
}
stateLookup = new Dictionary <object, FiniteStateMapping>();
for (int i = 0; i < values.Length; i++)
{
var mapping = new FiniteStateMapping((Enum)values.GetValue(i));
stateLookup.Add(mapping.state, mapping);
}
//Reflect methods
var methodBindingFlags = BindingFlags.FlattenHierarchy | BindingFlags.Instance | BindingFlags.DeclaredOnly | BindingFlags.Public |
BindingFlags.NonPublic;
// To refactor
var baseMethods = component.GetType().BaseType.GetMethods(methodBindingFlags);
var methods = baseMethods.Union(component.GetType().GetMethods(methodBindingFlags)).ToArray();
//Bind methods to states
var separator = "_".ToCharArray();
for (int i = 0; i < methods.Length; i++)
{
if (methods[i].GetCustomAttributes(typeof(CompilerGeneratedAttribute), true).Length != 0)
{
continue;
}
var names = methods[i].Name.Split(separator);
//Ignore functions without an underscore
if (names.Length <= 1)
{
continue;
}
Enum key;
try
{
key = (Enum)Enum.Parse(typeof(T), names[0]);
}
catch (ArgumentException)
{
//Not an method as listed in the state enum
continue;
}
var targetState = stateLookup[key];
switch (names[1])
{
case "Enter":
if (methods[i].ReturnType == typeof(IEnumerator))
{
targetState.hasEnterRoutine = true;
targetState.EnterRoutine = CreateDelegate <Func <IEnumerator> >(methods[i], component);
}
else
{
targetState.hasEnterRoutine = false;
targetState.EnterCall = CreateDelegate <Action>(methods[i], component);
}
break;
case "Exit":
if (methods[i].ReturnType == typeof(IEnumerator))
{
targetState.hasExitRoutine = true;
targetState.ExitRoutine = CreateDelegate <Func <IEnumerator> >(methods[i], component);
}
else
{
targetState.hasExitRoutine = false;
targetState.ExitCall = CreateDelegate <Action>(methods[i], component);
}
break;
case "Finally":
targetState.Finally = CreateDelegate <Action>(methods[i], component);
break;
case "Update":
targetState.Update = CreateDelegate <Action>(methods[i], component);
break;
case "LateUpdate":
targetState.LateUpdate = CreateDelegate <Action>(methods[i], component);
break;
case "FixedUpdate":
targetState.FixedUpdate = CreateDelegate <Action>(methods[i], component);
break;
case "OnCollisionEnter":
targetState.OnCollisionEnter = CreateDelegate <Action <Collision> >(methods[i], component);
break;
}
}
//Create nil state mapping
currentState = new FiniteStateMapping(null);
}
public void ChangeState(T newState, FiniteStateTransition transition)
{
if (stateLookup == null)
{
throw new Exception("States have not been configured, please call initialized before trying to set state");
}
if (!stateLookup.ContainsKey(newState))
{
throw new Exception("No state with the name " + newState.ToString() + " can be found. Please make sure you are called the correct type the statemachine was initialized with");
}
var nextState = stateLookup[newState];
if (currentState == nextState)
{
return;
}
//Cancel any queued changes.
if (queuedChange != null)
{
engine.StopCoroutine(queuedChange);
queuedChange = null;
}
switch (transition)
{
//case StateMachineTransition.Blend:
//Do nothing - allows the state transitions to overlap each other. This is a dumb idea, as previous state might trigger new changes.
//A better way would be to start the two couroutines at the same time. IE don't wait for exit before starting start.
//How does this work in terms of overwrite?
//Is there a way to make this safe, I don't think so?
//break;
case FiniteStateTransition.Safe:
if (isInTransition)
{
if (exitRoutine != null) //We are already exiting current state on our way to our previous target state
{
//Overwrite with our new target
destinationState = nextState;
return;
}
if (enterRoutine != null) //We are already entering our previous target state. Need to wait for that to finish and call the exit routine.
{
//Damn, I need to test this hard
queuedChange = WaitForPreviousTransition(nextState);
engine.StartCoroutine(queuedChange);
return;
}
}
break;
case FiniteStateTransition.Overwrite:
if (currentTransition != null)
{
engine.StopCoroutine(currentTransition);
}
if (exitRoutine != null)
{
engine.StopCoroutine(exitRoutine);
}
if (enterRoutine != null)
{
engine.StopCoroutine(enterRoutine);
}
//Note: if we are currently in an EnterRoutine and Exit is also a routine, this will be skipped in ChangeToNewStateRoutine()
break;
}
if ((currentState != null && currentState.hasExitRoutine) || nextState.hasEnterRoutine)
{
isInTransition = true;
currentTransition = ChangeToNewStateRoutine(nextState, transition);
engine.StartCoroutine(currentTransition);
}
else //Same frame transition, no coroutines are present
{
if (currentState != null)
{
currentState.ExitCall();
currentState.Finally();
}
lastState = currentState;
currentState = nextState;
if (currentState != null)
{
currentState.EnterCall();
if (Changed != null)
{
Changed((T)currentState.state);
}
}
isInTransition = false;
}
}
