#8 Make an Air Hockey Game in Unity – LOCAL MULTIPLAYER (Code)

In this tutorial, you will learn how to add a local multiplayer to air hockey in Unity. Together with the AI which we programmed earlier, this will provide the players of the game with ultimate freedom – play with friends on one device or play with AI.

Adding a local multiplayer isn’t as simple as just adding another player! It requires a completely new way in which we are handling the input. Let’s do it!

This post contains all the code that’s been written in this YouTube video.

PlayerController.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerController : MonoBehaviour {

    public List<PlayerMovement> Players = new List<PlayerMovement>();
	
	// Update is called once per frame
	void Update () {
		for (int i = 0; i < Input.touchCount; i++)
        {
            Vector2 touchWorldPos = Camera.main.ScreenToWorldPoint(Input.GetTouch(i).position);
            foreach (var player in Players)
            {
                if (player.LockedFingerID == null)
                {
                    if (Input.GetTouch(i).phase == TouchPhase.Began &&
                        player.PlayerCollider.OverlapPoint(touchWorldPos))
                    {
                        player.LockedFingerID = Input.GetTouch(i).fingerId;
                    }
                }
                else if (player.LockedFingerID == Input.GetTouch(i).fingerId)
                {
                    player.MoveToPosition(touchWorldPos);
                    if (Input.GetTouch(i).phase == TouchPhase.Ended ||
                        Input.GetTouch(i).phase == TouchPhase.Canceled)
                        player.LockedFingerID = null;
                }
            }
        }
	}
}

PlayerMovement.cs

using UnityEngine;

public class PlayerMovement : MonoBehaviour {

    Rigidbody2D rb;
    Vector2 startingPosition;

    public Transform BoundaryHolder;

    Boundary playerBoundary;

    public Collider2D PlayerCollider { get; private set; }

    public PlayerController Controller;

    public int? LockedFingerID { get; set; }

	// Use this for initialization
	void Start () {
        rb = GetComponent<Rigidbody2D>();
        startingPosition = rb.position;
        PlayerCollider = GetComponent<Collider2D>();

        playerBoundary = new Boundary(BoundaryHolder.GetChild(0).position.y,
                                      BoundaryHolder.GetChild(1).position.y,
                                      BoundaryHolder.GetChild(2).position.x,
                                      BoundaryHolder.GetChild(3).position.x);

    }

    private void OnEnable()
    {
        Controller.Players.Add(this);
    }
    private void OnDisable()
    {
        Controller.Players.Remove(this);
    }

    public void MoveToPosition(Vector2 position)
    {
        Vector2 clampedMousePos = new Vector2(Mathf.Clamp(position.x, playerBoundary.Left,
                                                  playerBoundary.Right),
                                      Mathf.Clamp(position.y, playerBoundary.Down,
                                                  playerBoundary.Up));
        rb.MovePosition(clampedMousePos);
    }

    public void ResetPosition()
    {
        rb.position = startingPosition;
    }
}