Fixing players so that game pads only control one character

Assets/Prefabs/Player.prefab

@@ -199,6 +199,7 @@ MonoBehaviour:
   moveActionName: Move
   jumpActionName: Jump
   controlSchemeName: Keyboard&Mouse
+  gamepadIndex: -1
   moveSpeed: 6
   jumpImpulse: 10
   groundMask:
@@ -221,6 +222,7 @@ MonoBehaviour:
   actionMapName: Player
   interactActionName: Crouch
   controlSchemeName: Keyboard&Mouse
+  gamepadIndex: -1
   holdPoint: {fileID: 5569302833446856119}
   pickupRange: 1
 --- !u!1 &6898135930931977916

Assets/Scenes/Level1.unity

@@ -467,6 +467,7 @@ MonoBehaviour:
   moveActionName: Move
   jumpActionName: Jump
   controlSchemeName: Gamepad
+  gamepadIndex: 0
   moveSpeed: 6
   jumpImpulse: 8
   groundMask:
@@ -670,6 +671,7 @@ MonoBehaviour:
   moveActionName: Move
   jumpActionName: Jump
   controlSchemeName: Gamepad
+  gamepadIndex: 1
   moveSpeed: 6
   jumpImpulse: 8
   groundMask:
@@ -873,6 +875,7 @@ MonoBehaviour:
   moveActionName: Move
   jumpActionName: Jump
   controlSchemeName: Gamepad
+  gamepadIndex: 2
   moveSpeed: 6
   jumpImpulse: 8
   groundMask:
@@ -1072,6 +1075,10 @@ PrefabInstance:
       propertyPath: m_LocalEulerAnglesHint.z
       value: 0
       objectReference: {fileID: 0}
+    - target: {fileID: 3659140714710275197, guid: 414ae949bae840c4589b38dd91c715e0, type: 3}
+      propertyPath: interactActionName
+      value: Interact
+      objectReference: {fileID: 0}
     - target: {fileID: 3937090937419967315, guid: 414ae949bae840c4589b38dd91c715e0, type: 3}
       propertyPath: m_Name
       value: Player

Assets/Scripts/PlayerPickupController.cs

@@ -1,3 +1,4 @@
+using System;
 using UnityEngine;
 using UnityEngine.InputSystem;
 
@@ -9,6 +10,8 @@ public class PlayerPickupController : MonoBehaviour
     private InputActionAsset runtimeActions;
     private InputAction interactAction;
     [SerializeField] private string controlSchemeName = "";
+    [SerializeField] private int gamepadIndex = -1;
+    private bool deviceFilterEnabled;
 
     [Header("Setup")]
     public Transform holdPoint; // Empty GameObject above head
@@ -29,6 +32,9 @@ public class PlayerPickupController : MonoBehaviour
         {
             runtimeActions.bindingMask = InputBinding.MaskByGroup(controlSchemeName);
         }
+        deviceFilterEnabled = ShouldFilterDevices();
+        ApplyDeviceFilter();
+        InputSystem.onDeviceChange += HandleDeviceChange;
 
         var map = runtimeActions.FindActionMap(actionMapName, true);
         interactAction = map.FindAction(interactActionName, true);
@@ -53,6 +59,8 @@ public class PlayerPickupController : MonoBehaviour
             runtimeActions.Disable();
             runtimeActions = null;
         }
+
+        InputSystem.onDeviceChange -= HandleDeviceChange;
     }
 
     private void OnInteractPerformed(InputAction.CallbackContext context)
@@ -113,4 +121,82 @@ public class PlayerPickupController : MonoBehaviour
         heldObject.transform.SetParent(null);
         heldObject = null;
     }
+
+    private bool ShouldFilterDevices()
+    {
+        return string.Equals(controlSchemeName, "Gamepad", StringComparison.OrdinalIgnoreCase) || gamepadIndex >= 0;
+    }
+
+    private void ApplyDeviceFilter()
+    {
+        if (!deviceFilterEnabled || runtimeActions == null)
+        {
+            return;
+        }
+
+        var targetIndex = ResolveGamepadIndex();
+        if (targetIndex < 0)
+        {
+            return;
+        }
+
+        if (Gamepad.all.Count <= targetIndex)
+        {
+            runtimeActions.devices = Array.Empty<InputDevice>();
+            return;
+        }
+
+        runtimeActions.devices = new InputDevice[] { Gamepad.all[targetIndex] };
+    }
+
+    private void HandleDeviceChange(InputDevice device, InputDeviceChange change)
+    {
+        if (!deviceFilterEnabled)
+        {
+            return;
+        }
+
+        if (change == InputDeviceChange.Added || change == InputDeviceChange.Removed || change == InputDeviceChange.Reconnected)
+        {
+            ApplyDeviceFilter();
+        }
+    }
+
+    private int ResolveGamepadIndex()
+    {
+        if (gamepadIndex >= 0)
+        {
+            return gamepadIndex;
+        }
+
+        if (string.IsNullOrWhiteSpace(actionMapName))
+        {
+            return -1;
+        }
+
+        if (string.Equals(actionMapName, "Player", StringComparison.OrdinalIgnoreCase))
+        {
+            return 0;
+        }
+
+        var end = actionMapName.Length - 1;
+        var start = end;
+        while (start >= 0 && char.IsDigit(actionMapName[start]))
+        {
+            start--;
+        }
+
+        start++;
+        if (start > end)
+        {
+            return -1;
+        }
+
+        if (!int.TryParse(actionMapName.Substring(start, end - start + 1), out var parsed))
+        {
+            return -1;
+        }
+
+        return parsed > 0 ? parsed - 1 : -1;
+    }
 }

Assets/Scripts/PlayerPlatformerController.cs

@@ -1,3 +1,4 @@
+using System;
 using UnityEngine;
 using UnityEngine.InputSystem;
 
@@ -10,6 +11,7 @@ public class PlayerPlatformerController : MonoBehaviour
     [SerializeField] private string moveActionName = "Move";
     [SerializeField] private string jumpActionName = "Jump";
     [SerializeField] private string controlSchemeName = "";
+    [SerializeField] private int gamepadIndex = -1;
     [SerializeField] private float moveSpeed = 6f;
     [SerializeField] private float jumpImpulse = 8f;
     [SerializeField] private LayerMask groundMask = ~0;
@@ -20,6 +22,7 @@ public class PlayerPlatformerController : MonoBehaviour
     private InputActionAsset runtimeActions;
     private InputAction moveAction;
     private InputAction jumpAction;
+    private bool deviceFilterEnabled;
 
     private void Awake()
     {
@@ -40,6 +43,9 @@ public class PlayerPlatformerController : MonoBehaviour
         {
             runtimeActions.bindingMask = InputBinding.MaskByGroup(controlSchemeName);
         }
+        deviceFilterEnabled = ShouldFilterDevices();
+        ApplyDeviceFilter();
+        InputSystem.onDeviceChange += HandleDeviceChange;
 
         var map = runtimeActions.FindActionMap(actionMapName, true);
         moveAction = map.FindAction(moveActionName, true);
@@ -68,6 +74,8 @@ public class PlayerPlatformerController : MonoBehaviour
             runtimeActions.Disable();
             runtimeActions = null;
         }
+
+        InputSystem.onDeviceChange -= HandleDeviceChange;
     }
 
     private void FixedUpdate()
@@ -96,6 +104,84 @@ public class PlayerPlatformerController : MonoBehaviour
         body.AddForce(Vector2.up * jumpImpulse, ForceMode2D.Impulse);
     }
 
+    private bool ShouldFilterDevices()
+    {
+        return string.Equals(controlSchemeName, "Gamepad", StringComparison.OrdinalIgnoreCase) || gamepadIndex >= 0;
+    }
+
+    private void ApplyDeviceFilter()
+    {
+        if (!deviceFilterEnabled || runtimeActions == null)
+        {
+            return;
+        }
+
+        var targetIndex = ResolveGamepadIndex();
+        if (targetIndex < 0)
+        {
+            return;
+        }
+
+        if (Gamepad.all.Count <= targetIndex)
+        {
+            runtimeActions.devices = Array.Empty<InputDevice>();
+            return;
+        }
+
+        runtimeActions.devices = new InputDevice[] { Gamepad.all[targetIndex] };
+    }
+
+    private void HandleDeviceChange(InputDevice device, InputDeviceChange change)
+    {
+        if (!deviceFilterEnabled)
+        {
+            return;
+        }
+
+        if (change == InputDeviceChange.Added || change == InputDeviceChange.Removed || change == InputDeviceChange.Reconnected)
+        {
+            ApplyDeviceFilter();
+        }
+    }
+
+    private int ResolveGamepadIndex()
+    {
+        if (gamepadIndex >= 0)
+        {
+            return gamepadIndex;
+        }
+
+        if (string.IsNullOrWhiteSpace(actionMapName))
+        {
+            return -1;
+        }
+
+        if (string.Equals(actionMapName, "Player", StringComparison.OrdinalIgnoreCase))
+        {
+            return 0;
+        }
+
+        var end = actionMapName.Length - 1;
+        var start = end;
+        while (start >= 0 && char.IsDigit(actionMapName[start]))
+        {
+            start--;
+        }
+
+        start++;
+        if (start > end)
+        {
+            return -1;
+        }
+
+        if (!int.TryParse(actionMapName.Substring(start, end - start + 1), out var parsed))
+        {
+            return -1;
+        }
+
+        return parsed > 0 ? parsed - 1 : -1;
+    }
+
     private bool IsGrounded()
     {
         var bounds = bodyCollider.bounds;