feat: integrate composable Godot runtime and EventBus debugger

Godot/Packages/ShrinkSDK.EntJoy.Godot/ShrinkEntJoyHost.cs

@@ -0,0 +1,96 @@
+#nullable enable
+
+using System;
+using System.Threading;
+using EntJoy.ECS;
+using EntJoy.JobSystem;
+using Godot;
+using ShrinkSDK.Godot;
+
+namespace ShrinkSDK.EntJoy.Godot;
+
+/// <summary>Godot node that owns an EntJoy World and advances its frame boundary.</summary>
+public partial class ShrinkEntJoyHost : ShrinkGodotHost
+{
+    private static readonly object SchedulerGate = new();
+    private static int SchedulerUsers;
+    private bool _schedulerAcquired;
+    private bool _worldDisposed;
+    private ulong _lastFrame = ulong.MaxValue;
+    private SceneTree? _tree;
+
+    [Export] public string EntJoyWorldName { get; set; } = "GodotWorld";
+
+    public World? EntJoyWorld { get; private set; }
+
+    public override void _Ready()
+    {
+        base._Ready();
+        AcquireScheduler();
+        EntJoyWorld = new World(EntJoyWorldName);
+        World.DefaultWorld = EntJoyWorld;
+        _tree = GetTree();
+        _tree.ProcessFrame += OnProcessFrame;
+        TreeExited += OnTreeExited;
+    }
+
+    public override void _Process(double delta)
+    {
+        base._Process(delta);
+        Advance();
+    }
+
+    private void OnProcessFrame() => Advance();
+
+    private void Advance()
+    {
+        if (EntJoyWorld == null || _worldDisposed) return;
+        var frame = Engine.GetProcessFrames();
+        if (frame == _lastFrame) return;
+        _lastFrame = frame;
+        EntJoyWorld.NextFrameEvents();
+        NativeJobScheduler.EndFrame();
+        EntJoyWorld.CurrentFrame++;
+    }
+
+    public override void _ExitTree()
+    {
+        DisposeWorld();
+        base._ExitTree();
+    }
+
+    private void OnTreeExited()
+    {
+        if (_tree != null)
+            _tree.ProcessFrame -= OnProcessFrame;
+        _tree = null;
+        TreeExited -= OnTreeExited;
+        DisposeWorld();
+    }
+
+    private void AcquireScheduler()
+    {
+        lock (SchedulerGate)
+        {
+            if (SchedulerUsers++ == 0)
+                NativeJobScheduler.Initialize();
+            _schedulerAcquired = true;
+        }
+    }
+
+    private void DisposeWorld()
+    {
+        if (_worldDisposed) return;
+        _worldDisposed = true;
+        EntJoyWorld?.Dispose();
+        EntJoyWorld = null;
+
+        if (!_schedulerAcquired) return;
+        lock (SchedulerGate)
+        {
+            _schedulerAcquired = false;
+            if (--SchedulerUsers == 0)
+                NativeJobScheduler.Shutdown();
+        }
+    }
+}