Made the Advance Button disable when it should

godot/TAS_system/TAS_System.cs

@@ -33,6 +33,11 @@ public partial class TAS_System : Node
         private set { this._currentFrame = value; }
     }
 
+    public int AdvancedFramesRemaining
+    {
+        get { return this.LastAdvancedFrame - this.CurrentFrame; }
+    }
+
     /// <summary>
     /// The last frame that can be advanced to. This will
     /// only be greater than CurrentFrame after the player

godot/UI/TAS UI/AdvanceButton.cs

@@ -3,15 +3,25 @@ using System;
 
 public partial class AdvanceButton : Button
 {
+	TAS_System TAS;
 	// Called when the node enters the scene tree for the first time.
 	public override void _Ready()
 	{
-		TAS_System TAS = GetNode<TAS_System>("/root/TAS_System");
+		TAS = GetNode<TAS_System>("/root/TAS_System");
 		this.Pressed += () => { TAS.Advance(1); };
+		
 	}
 
 	// Called every frame. 'delta' is the elapsed time since the previous frame.
 	public override void _Process(double delta)
 	{
+		if (TAS.AdvancedFramesRemaining == 0)
+		{
+			this.Disabled = true;
+		}
+		else
+		{
+			this.Disabled = false;
+		}
 	}
 }

godot/UI/TAS UI/TAS UI.tscn

@@ -63,6 +63,7 @@ anchor_left = 0.5
 anchor_right = 1.0
 anchor_bottom = 1.0
 grow_vertical = 2
+disabled = true
 text = "Advance"
 script = ExtResource("3_0ti6q")