void OnTriggerEnter2D(Collider2D target)
    {
        Debug.Log("Hit player");
        if (target.gameObject.tag == "PlayerHitBox")
        {
            // screen shake
            ActionController ac = target.gameObject.transform.root.GetComponent <ActionController>();

            if (ac != null)
            {
                if (characterManager.state == CharacterState.punching)
                {
                    ac.ApplyDamage(characterManager.punchDamage);
                }
                else if (characterManager.state == CharacterState.kicking)
                {
                    ac.ApplyDamage(characterManager.kickDamage);
                }
                else if (characterManager.state == CharacterState.heavyPunching)
                {
                    ac.ApplyDamage(characterManager.heavyPunchDamage);
                }
            }
        }
    }