===== StateMachines v2 ===== * https://github.com/THBA-HTX/fsm_demo Princip:


using Godot;
using System;

public partial class AIController : CharacterBody2D
{
    [Export] public float SpeedWalk = 1.5f;
    [Export] public float SpeedRun = 10f;
    private float CurrentSpeed;

    public Boolean IsRunning = false;
    public Boolean IsStopped = false;

    public CharacterBody2D Player;  // reference til vores Spiller
    public float PlayerDistance;

    Vector2 NextDest;   // Hvad er næste destination..gemmes her
    Vector2 MoveDirection;

    [Signal] public delegate void TargetReachedEventHandler();


    public override void _Ready()
    {
        // Vi opretter reference til vores Spiller
        Player = (CharacterBody2D) GetTree().GetNodesInGroup("Player")[0];
    }

    public override void _Process(double delta)
    {
        if (Player != null)
        {
            PlayerDistance = GlobalPosition.DistanceTo(Player.GlobalPosition);
        }
        // GD.Print("Player Distance er: " + PlayerDistance.ToString());
    }

    public override void _PhysicsProcess(double delta)
    {
        MoveDirection = GlobalPosition.DirectionTo(NextDest).Normalized();

        if ( GlobalPosition.DistanceTo(NextDest) <= 0.8f)
        {   // Sender signal om at vi har nået vores destination til abonnenter
            EmitSignal(nameof(TargetReached));
        }

        // Hvis AI er stopped, så sæt retning til 0.
        if (IsStopped == true) {
            MoveDirection = Vector2.Zero;
        }

        if (IsRunning == true)
        {
            CurrentSpeed = SpeedRun;
        }
        else {
            CurrentSpeed = SpeedWalk;
        }

        Velocity = MoveDirection * CurrentSpeed;
        MoveAndSlide();
    }

    public void MoveToPosition(Vector2 pos) 
    {
        IsStopped = false;
        NextDest = pos;
    }
}

==== StateMachine ====


using Godot;
using Godot.Collections;
using System;

public partial class StateMachine : Node
{
    // Den state vi starter i
    [Export] public State initialState;
    private State _currentState; // Nuværende tilstand

    // I denne ordbog kan jeg gemme alle mine states.
    private Dictionary _states;

    public override void _Ready()
    {
        // Opretter ordbog, som jeg erklærede tidligere.
        _states = new Dictionary();

        if (initialState == null) {
            GD.Print("Thomas du har glemt at sætte InitialState .. stram op.");
        }

        // Jeg kigger hvem jeg har som børn  :D mmkay.
        foreach (Node child in this.GetChildren()) {
            if (child is State s) {
                _states[s.Name] = s;
                s.Initialize();
            }
        }
        ChangeState(initialState.Name); // Skift til start tilstand
        GD.Print("StateMachine is ready.");
    }

    public void ChangeState(string stateName) {
        if (!_states.ContainsKey(stateName) || _currentState == _states[stateName] )
        {
            return; // HOP UD !!! gør ikke mere
        }

        if (_currentState != null)
            _currentState.Exit();   // Vi hopper af nuværende tilstand (oprydning)

        _currentState = _states[stateName]; // sætter nuværende tilstand til nye tilstand.
        _currentState.Enter();  // Initialisere

        GD.Print("Changed state to: " + stateName);
    }

    override public void _Process(double delta) {
        _currentState.Update(delta);
    }

    public override void _PhysicsProcess(double delta)
    {
        _currentState.PhysicsUpdate(delta);
    }

    public void OnTargetReached() {
        if (_currentState != null) {
            _currentState.NavigationComplete();
        }
    }

}

==== PatrolState ====


using Godot;
using System;

public partial class PatrolState : State
{
    [Export] public Node2D[] waypoints;
    [Export] public float ChaseRange = 120f;

    private int _currentWaypointIndex = 0;

    override public void Enter() {
        base.Enter();   // Kalder den klasse State som vi nedarver fra.
        Controller.MoveToPosition( waypoints[_currentWaypointIndex].GlobalPosition );
    }

    override public void Update(double delta) {
        if (Controller.PlayerDistance < ChaseRange) {
            fsm.ChangeState("Chase");
        }
    }

    override public void NavigationComplete() {
        _currentWaypointIndex++;
        // Hvis vi er nået til sidste waypoint, så sæt næste waypoint til index 0.
        if (_currentWaypointIndex >= waypoints.Length) {
            _currentWaypointIndex = 0;
        }

        Controller.MoveToPosition( waypoints[_currentWaypointIndex].GlobalPosition );
    }
}