SupaLidlGame/State/StateMachine.cs

60 lines
1.4 KiB
C#

using Godot;
using SupaLidlGame.Extensions;
namespace SupaLidlGame.State;
public abstract partial class StateMachine<T> : Node where T : Node, IState<T>
{
public T CurrentState { get; protected set; }
public abstract T InitialState { get; set; }
public override void _Ready()
{
ChangeState(InitialState);
}
public virtual bool ChangeState(T nextState, bool isProxied = false)
{
if (nextState is null)
{
return false;
}
// NOTE: proxied states can call Exit() more than once
if (CurrentState is not null)
{
CurrentState.Exit(nextState);
}
var previousState = CurrentState;
CurrentState = nextState;
// if the next state decides it should enter a different state,
// then we enter that different state instead
var nextNextState = nextState.Enter(previousState);
if (nextNextState is T t)
{
return ChangeState(t, true);
}
return true;
}
/// <summary>
/// Changes the current state to a state of type U which must inherit from T.
/// </summary>
public bool ChangeState<U>(out U state) where U : T
{
state = this.FindChildOfType<U>();
return ChangeState(state);
}
public bool ChangeState(string name, out T state)
{
state = GetNode<T>(name);
return ChangeState(state);
}
}