feat: time systems added

Engine.Systems/Time/TimerBehaviour.cs

@@ -0,0 +1,118 @@
+using Syntriax.Engine.Core;
+using Syntriax.Engine.Core.Abstract;
+
+namespace Syntriax.Engine.Systems.Time;
+
+public class TimerBehaviour : Behaviour, ITimer
+{
+    public event IReadOnlyTimer.TimerEventHandler? OnStarted = null;
+    public event IReadOnlyTimer.TimerDeltaEventHandler? OnDelta = null;
+    public event IReadOnlyTimer.TimerEventHandler? OnStopped = null;
+    public event IReadOnlyTimer.TimerEventHandler? OnPaused = null;
+    public event IReadOnlyTimer.TimerEventHandler? OnResumed = null;
+
+    public TimerState State { get; protected set; } = TimerState.Idle;
+    public double StartTime { get; protected set; } = 0f;
+    public float Percentage => (float)(1f - (Remaining / StartTime));
+
+    private double _remaining = 0f;
+    public double Remaining
+    {
+        get => _remaining;
+        protected set
+        {
+            if (value < .0f)
+                value = .0f;
+
+            _remaining = value;
+        }
+    }
+
+    private bool shouldBeTicking = false;
+    private bool hasStartedTickingBefore = false;
+
+    public virtual void TimerStart(double time)
+    {
+        StartTime = time;
+        Remaining = time;
+
+        shouldBeTicking = true;
+        hasStartedTickingBefore = false;
+
+        if (IsActive)
+            StartTimer();
+    }
+
+    public virtual void TimerStop()
+    {
+        if (!shouldBeTicking)
+            return;
+
+        shouldBeTicking = false;
+
+        State = TimerState.Stopped;
+        OnStopped?.Invoke(this);
+    }
+
+    protected override void OnUpdate()
+    {
+        if (State is not TimerState.Ticking)
+            return;
+
+        double delta = GameManager.Time.DeltaSpan.TotalSeconds;
+
+        Remaining -= delta;
+        OnDelta?.Invoke(this, delta);
+
+        if (Remaining <= .0f)
+            TimerStop();
+    }
+
+    protected override void OnEnteredHierarchy(IGameManager gameManager)
+    {
+        if (!shouldBeTicking || State is TimerState.Ticking)
+            return;
+
+        if (hasStartedTickingBefore)
+            TimerResume();
+        else
+            StartTimer();
+    }
+
+    protected override void OnExitedHierarchy(IGameManager gameManager)
+    {
+        if (!shouldBeTicking || State is not TimerState.Ticking)
+            return;
+
+        TimerPause();
+    }
+
+    public virtual void TimerPause()
+    {
+        State = TimerState.Paused;
+        OnPaused?.Invoke(this);
+    }
+
+    public virtual void TimerResume()
+    {
+        State = TimerState.Ticking;
+        OnResumed?.Invoke(this);
+    }
+
+    private void StartTimer()
+    {
+        hasStartedTickingBefore = true;
+
+        State = TimerState.Ticking;
+        OnStarted?.Invoke(this);
+    }
+
+    protected override void OnFinalize()
+    {
+        StartTime = 0f;
+        Remaining = 0f;
+        State = TimerState.Idle;
+        shouldBeTicking = false;
+        hasStartedTickingBefore = false;
+    }
+}