Changelog.md

Changelog

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In progress (1.10)

Added

• Ghost states: Ghost states are states that the state machine does not want to remain in and will try to exit as soon as possible. This means that the fsm can do multiple transitions in one OnLogic call. The "ghost state behaviour" is supported by all state types by setting the isGhostState field.

  E.g.

  fsm.AddState("A", onEnter: s => print("A"));
  fsm.AddState("B", new State(onEnter: s => print("B"), isGhostState: true));
  fsm.AddState("C", onEnter: s => print("C");
  
  fsm.AddTransition("A", "B");
  fsm.AddTransition("B", "C");
  
  fsm.Init(); // Prints "A"
  fsm.OnLogic(); // Prints "B" and then "C"

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1.9

Added

• Action system to allow for adding and calling custom functions apart from OnLogic.

  E.g.

  var state = new State()
    .AddAction("OnGameOver", () => print("Good game"))
    .AddAction<Collision2D>("OnCollision", collision => print(collision));
  
  fsm.AddState("State", state);
  fsm.Init();
  
  fsm.OnAction("OnGameOver");  // prints "Good game"
  fsm.OnAction<Collision2D>("OnCollision", new Collision2D());

• Two way transitions: New feature that lets the state machine transition from a source to a target state when a condition is true, and from the target to the source state when the condition is false:

  fsm.AddTwoWayTransition("Idle", "Shoot", t => isInRange);
  
  // Same as
  fsm.AddTransition("Idle", "Shoot", t => isInRange);
  fsm.AddTransition("Shoot", "Idle", t => ! isInRange);

  fsm.AddTwoWayTransition(transition);
  fsm.AddTwoWayTriggerTransition(transition);

• TransitionOnMouse classes for readable transitions that should occur when a certain mouse button has been pressed / released / ... It is analogous to TransitionOnKey.

  E.g.:

  fsm.AddTransition(new TransitionOnMouse.Down("Idle", "Shoot", 0));

Improved

• Improved performance in many cases for value types as the state names (e.g. State<int>) by preventing boxing and minimising GC allocations

Changed

• The RequestExit() method of the StateBase class has been renamed to OnExitRequest() for more clarity.

• The "shortcut methods" of the state machine have been moved to a dedicated class as extension methods. This does not change the API or usage in any way, but makes the internal code cleaner. -> This change reduces the coupling between the base StateMachine class and the State / Transition classes. Instead, the StateMachine only depends on the StateBase and TransitionBase classes. This especially shows that the extension methods are optional and not necessary in a fundamental way.

• To allow for better testing and more customisation, references to the Timer class have been replaced with the ITimer interface. This allows you to write a custom timer for your use case and allows for time-based transitions to be tested more easily.

  // Previously
  if (timer > 2) { }
  
  // Now
  if (timer.Elapsed > 2) { }

• As a consequence of the way the action system was implemented, generic datatype of the input parameter of onEnter / onLogic / onExit for State and CoState has changed. The class State now requires two generic type parameters: One for the type of its ID and one for the type of the IDs of the actions.

  Previously:

  void FollowPlayer(State<string> state)
  {
      // ...
  }
  
  fsm.AddState("FollowPlayer", onLogic: FollowPlayer);

  Now:

  void FollowPlayer(State<string, string> state)
  {
      // ...
  }
  
  fsm.AddState("FollowPlayer", onLogic: FollowPlayer);

• (Internal change) Restructured the src folder to make it cleaner

Fixed

• Fix ArgumentNullException when using the AddTransitionFromAny shortcut method

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1.8 - Generics

Version 1.8 of UnityHFSM adds support for generics. Now the datatype of state identifiers / names and the type of event names can be easily changed. Thanks to the new "shortcut methods", state machines can be written with less boilerplate than ever and certain cases, such as empty states, can be optimised automatically for you.

Added

• Support for generics for the state identifiers and event names

• "Shortcut methods" for reduced boilerplate and automatic optimisation

  fsm.AddState("FollowPlayer", new State(
      onLogic: s => MoveTowardsPlayer()
  ));
  // Now
  fsm.AddState("FollowPlayer", onLogic: s => MoveTowardsPlayer());

  fsm.AddState("ExtractIntel", new State());
  // Now
  fsm.AddState("ExtractIntel");

  fsm.AddTransition(new Transition("A", "B"));
  // Now
  fsm.AddTransition("A", "B");

• Support for installing the package via Unity's Package Manager UPM

• Project samples

Changed

• The datatype of the input parameter of onEnter / onLogic / onExit for State has changed. This is due to the inheritance hierarchy and the way generic support was added to the codebase while still trying to retain the ease of use of the string versions.

  Previously:

  void FollowPlayer(State state)
  {
      // ...
  }
  
  fsm.AddState("FollowPlayer", new State(onLogic: FollowPlayer));

  Now:

  void FollowPlayer(State<string> state)
  {
      // ...
  }
  
  fsm.AddState("FollowPlayer", new State(onLogic: FollowPlayer));

• States and transitions no longer carry a reference to the MonoBehaviour by default.

  • Now the constructor of StateMachine does not require mono anymore => new StateMachine() instead of new StateMachine(this)

  • The reference to mono has to be passed into the CoState constructor => new CoState(this, ...)

Fixed

• Fix KeyNotFoundException being thrown when an event is activated while no active trigger transition use this event

• Fix incorrect order of events on state changes, which called the OnEnter method before the new active transitions / trigger transitions had been loaded

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