✨ Usable multiplayer

Scenes/Player.tscn

@@ -1,13 +1,32 @@
-[gd_scene load_steps=4 format=3 uid="uid://b3gx0bl43lku3"]
+[gd_scene load_steps=7 format=3 uid="uid://b3gx0bl43lku3"]
 
 [ext_resource type="Script" path="res://Scripts/Player.cs" id="1_0btyt"]
 [ext_resource type="Texture2D" uid="uid://c4als6t3k4myc" path="res://Sprites/Player.png" id="1_cqpqa"]
+[ext_resource type="Script" path="res://Scripts/Logic/PlayerInput.cs" id="3_tvoua"]
 
 [sub_resource type="CircleShape2D" id="CircleShape2D_68yf8"]
 radius = 26.0768
 
-[node name="Player" type="CharacterBody2D" node_paths=PackedStringArray("PlayerDashCountdown")]
+[sub_resource type="SceneReplicationConfig" id="SceneReplicationConfig_bekoo"]
+properties/0/path = NodePath(".:position")
+properties/0/spawn = true
+properties/0/replication_mode = 1
+properties/1/path = NodePath(".:PlayerId")
+properties/1/spawn = true
+properties/1/replication_mode = 1
+
+[sub_resource type="SceneReplicationConfig" id="SceneReplicationConfig_hojn2"]
+properties/0/path = NodePath("InputSynchronizer:IsDashing")
+properties/0/spawn = true
+properties/0/replication_mode = 1
+properties/1/path = NodePath("InputSynchronizer:MovementDirection")
+properties/1/spawn = true
+properties/1/replication_mode = 1
+
+[node name="Player" type="CharacterBody2D" node_paths=PackedStringArray("PlayerCamera", "PlayerInput", "PlayerDashCountdown")]
 script = ExtResource("1_0btyt")
+PlayerCamera = NodePath("Camera2D")
+PlayerInput = NodePath("InputSynchronizer")
 PlayerDashCountdown = NodePath("DashCountdown")
 
 [node name="Sprite2D" type="Sprite2D" parent="."]
@@ -18,5 +37,18 @@ texture = ExtResource("1_cqpqa")
 [node name="CollisionShape2D" type="CollisionShape2D" parent="."]
 shape = SubResource("CircleShape2D_68yf8")
 
+[node name="Camera2D" type="Camera2D" parent="."]
+enabled = false
+process_callback = 0
+position_smoothing_enabled = true
+rotation_smoothing_enabled = true
+
 [node name="DashCountdown" type="Timer" parent="."]
 one_shot = true
+
+[node name="MultiplayerSynchronizer" type="MultiplayerSynchronizer" parent="."]
+replication_config = SubResource("SceneReplicationConfig_bekoo")
+
+[node name="InputSynchronizer" type="MultiplayerSynchronizer" parent="."]
+replication_config = SubResource("SceneReplicationConfig_hojn2")
+script = ExtResource("3_tvoua")

Scenes/Root.tscn

@@ -1,26 +1,23 @@
-[gd_scene load_steps=4 format=3 uid="uid://bjhmjrldq4lkt"]
+[gd_scene load_steps=5 format=3 uid="uid://bjhmjrldq4lkt"]
 
 [ext_resource type="Script" path="res://Scripts/Multiplayer.cs" id="1_fym13"]
 [ext_resource type="PackedScene" uid="uid://b3gx0bl43lku3" path="res://Scenes/Player.tscn" id="1_vby0g"]
 [ext_resource type="PackedScene" uid="uid://bvll23f5ibd4v" path="res://Scenes/UI/MultiplayerUI.tscn" id="2_7o53i"]
+[ext_resource type="Script" path="res://Scripts/Logic/World.cs" id="3_xwguj"]
 
 [node name="Node" type="Node"]
 
-[node name="MultiplayerNode" type="Node" parent="." node_paths=PackedStringArray("Playground")]
+[node name="MultiplayerNode" type="Node" parent="." node_paths=PackedStringArray("World")]
 script = ExtResource("1_fym13")
-Playground = NodePath("../Playground")
+World = NodePath("../World")
 
 [node name="MultiplayerUi" parent="." node_paths=PackedStringArray("MultiplayerController") instance=ExtResource("2_7o53i")]
 MultiplayerController = NodePath("../MultiplayerNode")
 
-[node name="Playground" type="Node2D" parent="."]
+[node name="World" type="Node2D" parent="."]
+script = ExtResource("3_xwguj")
+PlayerScene = ExtResource("1_vby0g")
 
-[node name="Camera2D" type="Camera2D" parent="Playground"]
+[node name="MultiplayerSpawner" type="MultiplayerSpawner" parent="."]
-enabled = false
+_spawnable_scenes = PackedStringArray("res://Scenes/Player.tscn")
-process_callback = 0
+spawn_path = NodePath("../World")
-position_smoothing_enabled = true
-rotation_smoothing_enabled = true
-
-[node name="Player" parent="Playground" node_paths=PackedStringArray("PlayerCamera") instance=ExtResource("1_vby0g")]
-position = Vector2(0, 2)
-PlayerCamera = NodePath("../Camera2D")

Scripts/Logic/PlayerInput.cs

@@ -0,0 +1,33 @@
+using Godot;
+
+namespace CodingLand.Scripts.Logic;
+
+public partial class PlayerInput : MultiplayerSynchronizer
+{
+    [Export] public bool IsDashing;
+
+    [Export] public Vector2 MovementDirection;
+
+    public override void _Ready()
+    {
+        if (GetMultiplayerAuthority() != Multiplayer.GetUniqueId())
+        {
+            SetProcess(false);
+            SetPhysicsProcess(false);
+        }
+    }
+
+    [Rpc(CallLocal = true)]
+    private void Dash()
+    {
+        IsDashing = true;
+    }
+
+    public override void _Process(double delta)
+    {
+        MovementDirection = Input.GetVector("move_left", "move_right", "move_up", "move_down");
+
+        if (Input.IsActionJustPressed("move_dash"))
+            Rpc(nameof(Dash));
+    }
+}

Scripts/Logic/World.cs

@@ -0,0 +1,68 @@
+using System.Numerics;
+using Godot;
+using Vector2 = Godot.Vector2;
+
+namespace CodingLand.Scripts.Logic;
+
+public partial class World : Node2D
+{
+    [Export] public PackedScene PlayerScene;
+
+    public void StartGame()
+    {
+        if (!Multiplayer.IsServer())
+            return;
+
+        // Handling player connect / disconnect after this client connected
+        Multiplayer.PeerDisconnected += RemovePlayer_Adaptor;
+        Multiplayer.PeerConnected += AddPlayer_Adaptor;
+
+        // Handling player connected before this client
+        foreach (var id in Multiplayer.GetPeers())
+            AddPlayer(id);
+
+        // Add this client as a player if client isn't a dedicated server
+        if (!OS.HasFeature("dedicated_server"))
+            AddPlayer(1);
+    }
+
+    public override void _ExitTree()
+    {
+        if (!Multiplayer.IsServer())
+            return;
+
+        Multiplayer.PeerDisconnected -= RemovePlayer_Adaptor;
+        Multiplayer.PeerConnected -= AddPlayer_Adaptor;
+    }
+
+    private string BuildPlayerName(int id)
+    {
+        return $"Player#{id}";
+    }
+
+    private void AddPlayer_Adaptor(long id)
+        => AddPlayer((int)id);
+
+    private void RemovePlayer_Adaptor(long id)
+        => RemovePlayer((int)id);
+
+    private void AddPlayer(int id)
+    {
+        var player = PlayerScene.Instantiate<Player>();
+        player.SetPlayerId(id);
+        var position = Vector2.FromAngle(GD.Randf() * 2 * Mathf.Pi);
+        player.Position = new Vector2(position.X * 5f * GD.Randf(), position.Y * 5f * GD.Randf());
+        player.Name = BuildPlayerName(id);
+
+        AddChild(player, true);
+    }
+
+    private void RemovePlayer(int id)
+    {
+        var name = BuildPlayerName(id);
+        if (!HasNode(name))
+            return;
+
+        GetNode(name).QueueFree();
+    }
+}

Scripts/Multiplayer.cs

@@ -1,23 +1,22 @@
-using System;
+using CodingLand.Scripts.Logic;
 using Godot;
 
 namespace CodingLand.Scripts;
 
 public partial class Multiplayer : Node
 {
-	[Export] public Node2D Playground;
+	[Export] public World World;
 	
 	private void GameFreeze()
 	{
-		Playground.Hide();
 		GetTree().Paused = true;
+		World.Hide();
 	}
 
 	private void GameUnfreeze()
 	{
-		Playground.Show();
-		Playground.GetNode<Camera2D>("Camera2D").Enabled = true;
 		GetTree().Paused = false;
+		World.Show();
 	}
 	
 	public override void _Ready()
@@ -42,8 +41,11 @@ public partial class Multiplayer : Node
 			return false;
 		}
 		
+		GD.Print("Running game as server...");
+
 		Multiplayer.MultiplayerPeer = peer;
 		GameUnfreeze();
+		World.StartGame();
 
 		return true;
 	}
@@ -62,8 +64,11 @@ public partial class Multiplayer : Node
 			return false;
 		}
 
+		GD.Print("Running game as client...");
+		
 		Multiplayer.MultiplayerPeer = peer;
 		GameUnfreeze();
+		World.StartGame();
 		
 		return true;
 	}

Scripts/Player.cs

@@ -1,39 +1,54 @@
-using System;
+using CodingLand.Scripts.Logic;
 using Godot;
 
 namespace CodingLand.Scripts;
 
 public partial class Player : CharacterBody2D
 {
+	private int _currentPlayerId = 1;
+	
 	[Export] public float MaxSpeed = 400f;
 	[Export] public float Acceleration = 500f;
 	[Export] public float Deceleration = 500f;
 	[Export] public float RotationSpeed = 5f;
 
-	[Export] public float CameraSmoothness = 0.05f;
-	
 	[Export] public Camera2D PlayerCamera;
 
+	[Export] public PlayerInput PlayerInput;
+
 	[Export] public Timer PlayerDashCountdown;
 	[Export] public float PlayerDashAcceleration = 2f;
 
+	[Export] public int PlayerId
+	{
+		get => _currentPlayerId;
+		set
+		{
+			_currentPlayerId = value;
+			PlayerInput.SetMultiplayerAuthority(value);
+		}
+	}
+
+	public void SetPlayerId(int id)
+	{
+		PlayerId = id;
+		PlayerInput.SetMultiplayerAuthority(id);
+	}
+
+	public override void _Ready()
+	{
+		if (PlayerId == Multiplayer.GetUniqueId())
+			PlayerCamera.Enabled = true;
+	}
+
 	public override void _PhysicsProcess(double delta)
 	{
-		var input = Vector2.Zero;
+		var input = PlayerInput.MovementDirection;
 
-		if (Input.IsActionPressed("move_right"))
-			input.X += 1;
-		if (Input.IsActionPressed("move_left"))
-			input.X -= 1;
-		if (Input.IsActionPressed("move_down"))
-			input.Y += 1;
-		if (Input.IsActionPressed("move_up"))
-			input.Y -= 1;
-
-		input = input.Normalized();
 
 		if (input != Vector2.Zero)
 		{
+			input = input.Normalized();
 			Velocity = Velocity.MoveToward(input * MaxSpeed, Acceleration * (float)delta);
 
 			var finalRotation = input.Angle() + Mathf.Pi / 2;
@@ -44,18 +59,14 @@ public partial class Player : CharacterBody2D
 			Velocity = Velocity.MoveToward(Vector2.Zero, Deceleration * (float)delta);
 		}
 
-		if (Input.IsActionJustPressed("move_dash") && PlayerDashCountdown.IsStopped())
+		if (PlayerInput.IsDashing && PlayerDashCountdown.IsStopped())
 		{
+			PlayerInput.IsDashing = false;
 			Velocity *= PlayerDashAcceleration;
 			PlayerDashCountdown.Start();
 		}
 
 		Position += Velocity * (float)delta;
 		MoveAndSlide();
-		
-		if (PlayerCamera != null)
-		{
-			PlayerCamera.Position = GlobalPosition;
-		}
 	}
 }

Scripts/UI/MultiplayerUi.cs

@@ -55,7 +55,7 @@ public partial class MultiplayerUi : Control
 			if (result)
 				Hide();
 		};
-		StartAsServerButton.Pressed += () =>
+		StartAsClientButton.Pressed += () =>
 		{
 			if (!DoValidation())
 			{