Unity2d GroundCheck

GroundCheck.cs

using UnityEngine;

[RequireComponent(typeof(BoxCollider2D))]
public class GroundCheck : MonoBehaviour
{
    public bool is_on_ground = false;
    [Range(0, 90)]
    public float MaxAngle = 45;
    private BoxCollider2D self;

    void Start()
    {
        self = GetComponent<BoxCollider2D>();
        self.isTrigger = true;
    }

    void FixedUpdate()
    {
        var pos = new Vector2(transform.position.x, transform.position.y);
        var hits = Physics2D.BoxCastAll(pos - self.offset, self.size, 0, Vector2.down, self.size.y);
        foreach (var item in hits)
        {
            if (item.transform.gameObject.tag == "Player") continue;
            var angle = Mathf.Atan2(item.normal.x, item.normal.y) * (180 / Mathf.PI);
            var fixedangle = Mathf.Abs(angle);
            if (fixedangle < MaxAngle)
            {
                is_on_ground = true;
                return;
            }
        }
        is_on_ground = false;
    }
}