Make pacman move randomly

Question

I am creating a pacman game using noobtuts' tutorial. https://noobtuts.com/unity/2d-pacman-game However I want to make pacman to be able move on its own. My idea is to make it choose a random direction to move, and it will head into that direction if it is a valid move. How should I do it? Appreciate any answers!

This is noobtuts' code that moves pacman with user input.

Vector2 dest = Vector2.zero;

    void Start()
    {
        dest = transform.position;
        disabled = false;
    }

    void FixedUpdate()
    {
        // Move closer to Destination
        Vector2 p = Vector2.MoveTowards(transform.position, dest, speed);
        GetComponent<Rigidbody2D>().MovePosition(p);

        // Check for Input if not moving
        if ((Vector2)transform.position == dest && !disabled)
        {
            if (DirectionEmulator.direction == "up" && valid(Vector2.up))
                dest = (Vector2)transform.position + Vector2.up;
            if (DirectionEmulator.direction == "right" && valid(Vector2.right))
                dest = (Vector2)transform.position + Vector2.right;
            if (DirectionEmulator.direction == "down" && valid(-Vector2.up))
                dest = (Vector2)transform.position - Vector2.up;
            if (DirectionEmulator.direction == "left" && valid(-Vector2.right))
                dest = (Vector2)transform.position - Vector2.right;
        }

        // Animation Parameters
        Vector2 dir = dest - (Vector2)transform.position;
        GetComponent<Animator>().SetFloat("DirX", dir.x);
        GetComponent<Animator>().SetFloat("DirY", dir.y);
    }

    bool valid(Vector2 dir)
    {
        // Cast Line from 'next to Pac-Man' to 'Pac-Man'
        Vector2 pos = transform.position;
        RaycastHit2D hit = Physics2D.Linecast(pos + dir, pos);
        return (hit.collider == GetComponent<Collider2D>());
    }

Answer 1

I managed to make it work as of now, but I believe much more can be improved. Please provide any input if you have any solutions!

   private string move;
    Vector2 dest = Vector2.zero;
    

    void Start()
    {
        dest = transform.position;
        disabled = false;
        move = "right";
    }

    void FixedUpdate() //use this to decide movement
    {
        // Move closer to Destination
        Vector2 p = Vector2.MoveTowards(transform.position, dest, speed);
        GetComponent<Rigidbody2D>().MovePosition(p);

        // determine next destination
        if ((Vector2)transform.position == dest && !disabled)
        {
            //check valid direction
            if (move == "up" && valid(Vector2.up))
            {
                dest = (Vector2)transform.position + Vector2.up;
            }

            if (move == "right" && valid(Vector2.right))
            {
                dest = (Vector2)transform.position + Vector2.right;
            }
                
            if (move == "down" && valid(-Vector2.up))
            {
                dest = (Vector2)transform.position - Vector2.up;
            }
                
            if (move == "left" && valid(-Vector2.right))
            {
                dest = (Vector2)transform.position - Vector2.right;
            }



            //if not valid, change direction
            // choose random valid direction
            System.Random rnd = new System.Random();
            int rand = rnd.Next(1, 4);

            if (rand == 1 && valid(Vector2.up))
            {
                move = "up";
            }
            else if (rand == 2 && valid(Vector2.right))
            {
                move = "right";
            }
            else if (rand == 3 && valid(-Vector2.up))
            {
                move = "down";
            }
            else if (rand == 4 && valid(-Vector2.right))
            {
                move = "left";
            }
        }

        // Animation Parameters
        Vector2 dir = dest - (Vector2)transform.position;
        GetComponent<Animator>().SetFloat("DirX", dir.x);
        GetComponent<Animator>().SetFloat("DirY", dir.y);
    }

    bool valid(Vector2 dir)
    {
        // Cast Line from 'next to Pac-Man' to 'Pac-Man'
        Vector2 pos = transform.position;
        RaycastHit2D hit = Physics2D.Linecast(pos + dir, pos);
        return (hit.collider == GetComponent<Collider2D>());
    }