CharacterController2D

using UnityEngine;
using UnityEngine.Events;

public class CharacterController2D : MonoBehaviour {
    [SerializeField] private float m_JumpForce = 400f; // Amount of force added when the player jumps.
    [Range (0, 1)][SerializeField] private float m_CrouchSpeed = .36f; // Amount of maxSpeed applied to crouching movement. 1 = 100%
    [Range (0, .3f)][SerializeField] private float m_MovementSmoothing = .05f; // How much to smooth out the movement
    [SerializeField] private bool m_AirControl = false; // Whether or not a player can steer while jumping;
    [SerializeField] private LayerMask m_WhatIsGround; // A mask determining what is ground to the character
    [SerializeField] private Transform m_GroundCheck; // A position marking where to check if the player is grounded.
    [SerializeField] private Transform m_CeilingCheck; // A position marking where to check for ceilings
    [SerializeField] private Collider2D m_CrouchDisableCollider; // A collider that will be disabled when crouching
    public int NumberOfJumps; // int describing number of jumps done
    public int MaxJumps; // max number of jumps

    const float k_GroundedRadius = .2f; // Radius of the overlap circle to determine if grounded
    public bool m_Grounded; // Whether or not the player is grounded.
    const float k_CeilingRadius = .2f; // Radius of the overlap circle to determine if the player can stand up
    private Rigidbody2D m_Rigidbody2D;
    private bool m_FacingRight = true; // For determining which way the player is currently facing.
    private Vector3 m_Velocity = Vector3.zero;

    [Header ("Events")]
    [Space]

    public UnityEvent OnLandEvent;

    [System.Serializable]
    public class BoolEvent : UnityEvent<bool> { }

    public BoolEvent OnCrouchEvent;
    private bool m_wasCrouching = false;

    private void Awake () {
        m_Rigidbody2D = GetComponent<Rigidbody2D> ();

        if (OnLandEvent == null)
            OnLandEvent = new UnityEvent ();

        if (OnCrouchEvent == null)
            OnCrouchEvent = new BoolEvent ();
    }

    private void FixedUpdate () {
        bool wasGrounded = m_Grounded;
        m_Grounded = false;

        // The player is grounded if a circlecast to the groundcheck position hits anything designated as ground
        // This can be done using layers instead but Sample Assets will not overwrite your project settings.
        Collider2D[] colliders = Physics2D.OverlapCircleAll (m_GroundCheck.position, k_GroundedRadius, m_WhatIsGround);
        for (int i = 0; i < colliders.Length; i++) {
            if (colliders[i].gameObject != gameObject) {
                m_Grounded = true;
                NumberOfJumps = 0;
                if (!wasGrounded)
                    OnLandEvent.Invoke ();
            }
        }
    }

    public void Move (float move, bool crouch, bool jump) {
        // If crouching, check to see if the character can stand up
        if (!crouch) {
            // If the character has a ceiling preventing them from standing up, keep them crouching
            if (Physics2D.OverlapCircle (m_CeilingCheck.position, k_CeilingRadius, m_WhatIsGround)) {
                crouch = true;
            }
        }

        //only control the player if grounded or airControl is turned on
        if (m_Grounded || m_AirControl) {

            // If crouching
            if (crouch) {
                if (!m_wasCrouching) {
                    m_wasCrouching = true;
                    OnCrouchEvent.Invoke (true);
                }

                // Reduce the speed by the crouchSpeed multiplier
                move *= m_CrouchSpeed;

                // Disable one of the colliders when crouching
                if (m_CrouchDisableCollider != null)
                    m_CrouchDisableCollider.enabled = false;
            } else {
                // Enable the collider when not crouching
                if (m_CrouchDisableCollider != null)
                    m_CrouchDisableCollider.enabled = true;

                if (m_wasCrouching) {
                    m_wasCrouching = false;
                    OnCrouchEvent.Invoke (false);
                }
            }

            // Move the character by finding the target velocity
            Vector3 targetVelocity = new Vector2 (move * 10f, m_Rigidbody2D.velocity.y);
            // And then smoothing it out and applying it to the character
            m_Rigidbody2D.velocity = Vector3.SmoothDamp (m_Rigidbody2D.velocity, targetVelocity, ref m_Velocity, m_MovementSmoothing);

            // If the input is moving the player right and the player is facing left...
            if (move > 0 && !m_FacingRight) {
                // ... flip the player.
                Flip ();
            }
            // Otherwise if the input is moving the player left and the player is facing right...
            else if (move < 0 && m_FacingRight) {
                // ... flip the player.
                Flip ();
            }
        }
        // If the player should jump...
        if (m_Grounded && jump) {
            // Add a vertical force to the player.
            NumberOfJumps = 1;
            m_Grounded = false;
            m_Rigidbody2D.AddForce (new Vector2 (0f, m_JumpForce));
        } else if (NumberOfJumps < MaxJumps && !m_Grounded && jump) {
            m_Rigidbody2D.AddForce (new Vector2 (0f, m_JumpForce));
            NumberOfJumps++;
        }
    }

    private void Flip () {
        // Switch the way the player is labelled as facing.
        m_FacingRight = !m_FacingRight;

        // Multiply the player's x local scale by -1.
        Vector3 theScale = transform.localScale;
        theScale.x *= -1;
        transform.localScale = theScale;
    }
}