The script below is ready to go, you can copy/paste it in your project and the game object you attach it to will be able to double and triple jump.
Keep in mind that the object needs to have a BoxCollider2D component attached on him and a Rigidbody2D component.
You also need to tag the game object that increases jump count with the appropriate tag.
public class Player : MonoBehavior
{
[SerializeField]
private float jumpForce = 10f;
private Rigidbody2D myBody;
// set the appropriate layer mask for the ground in the inspector
[SerializeField]
private LayerMask groundLayer;
// add an empty game object at the feet of the player object
[SerializeField]
private Transform groundCheckPos;
private BoxCollider2D boxCol2D;
private bool canJump, doubleJump;
private void Awake()
{
myBody = GetComponent<Rigidbody2D>();
boxCol2D = GetComponent<BoxCollider2D>();
}
private void Update()
{
IsGrounded();
HandleJumping();
}
void IsGrounded()
{
canJump = Physics2D.BoxCast(boxCol2D.bounds.center,
boxCol2D.bounds.size, 0f, Vector2.down, 0.1f, groundLayer);
}
void HandleJumping()
{
if (Input.GetButtonDown("Jump"))
{
if (canJump)
{
doubleJump = true;
myBody.velocity = new Vector2(myBody.velocity.x, jumpForce);
}
else if (doubleJump)
{
doubleJump = false;
myBody.velocity = new Vector2(myBody.velocity.x, jumpForce);
}
}
}
private void OnTriggerEnter2D(Collider2D collision)
{
// use your tag here
if (collision.CompareTag("Power"))
{
collision.gameObject.SetActive(false);
doubleJump = true;
}
}
}