State machine library for Unity. Inspired by Stateless.
var car = new StateMachine<CarState, CarAction>(State.Idle);
car.Configure(CarState.Idle)
.Permit(CarAction.Ignition, CarState.Running);
car.Configure(CarState.Running)
.PermitIf(CarAction.Crashed, CarState.Wrecked, () => health == 0);
car.Configure(CarState.Running)
.PermitDynamic(CarState.Idle, () => fuel == 0);
car.Configure(CarState.Running)
.Permit(CarAction.BoosterActivated, CarState.Boosting);
car.Configure(CarState.Boosting)
.OnEntry(BoostVelocity)
.PermitImmediate(CarState.Running);
car.Initialize();
car.Activate(CarAction.Ignition);Get the unitypackage
Standard state machine features supported:
- States and triggers of any type.
- Entry/exit state events.
- Conditional trigger transitions.
Unity-oriented features:
- State update events.
- Conditional transitions without triggers.
- Immediate transitions for intermediate states.
public class ItemActor : MonoBehaviour
{
// ...
private void Awake()
{
itemMachine = new StateMachine<ItemState, ItemTrigger>(ItemState.Dropped);
itemMachine.Configure(ItemState.Dropped)
.OnEntry(() => Debug.Log("Dropped."))
.OnExit(() => Debug.Log("Picked up"))
.OnUpdate(EmitAura);
itemMachine.Initialize();
}
private void Update()
{
itemMachine.Update();
}
// ...
}The state machine will transition to a new state as soon as the trigger is called.
car.Configure(CarState.Idle)
.Permit(CarAction.Ignition, CarState.Running);Unhandled triggers for the current state are ignored.
Transitions can be triggered by conditional triggers or can be based solely on external variable changes.
trader.Configure(TraderState.Waiting)
.PermitIf(TraderTrigger.Insulted, TraderState.Closed, () => reputation <= 0)
.PermitDynamic(TraderState.Closed, () => mood.Mediocre);Immediate transitions can be configured for intermediate states that need to do useful work and transition to another state right away.
movement.Configure(MoveState.Jumping)
.OnEntry(() => AddJumpImpulse)
.PermitImmediate(MoveState.Falling);StateChanged event can be used for observing state changes.
var baseMachine = new Machine<State, Trigger>(State.Default);
var observerMachine = new Machine<State, Trigger>(State.Default);
baseMachine.StateChanged += (Object sender, StateChangedEventArgs<State> args) => observerMachine.TransitionTo(args.NextState);