I'm trying to make the Player not jump continuously so I use isOnGrounded variable to check if the player is on the ground or not. Here is my code:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;

public class PlayerController : MonoBehaviour
{
    //REFERENCES
    private Rigidbody2D rb2D;
    //VARIABLES
    [SerializeField] float moveSpeed = 0;
    private float moveX;

    [SerializeField] bool isOnGrounded = true;
    [SerializeField] float jumpY;
    // Start is called before the first frame update
    void Start()
    {
        rb2D = GetComponent<Rigidbody2D>();
    }
    // Update is called once per frame
    void Update()
    {
        moveX = Input.GetAxis("Horizontal");
        PlayerJump();
    }
    private void FixedUpdate()
    {
        PlayerMove();

    }
    void PlayerMove()
    {
        rb2D.velocity = new Vector2(moveX * moveSpeed * Time.fixedDeltaTime, rb2D.velocity.y);

    }
    void PlayerJump()
    {
        if (Input.GetKeyDown(KeyCode.Space) && isOnGrounded == true)
        {
            rb2D.AddForce(new Vector2(rb2D.velocity.x, jumpY));
        }
    }
    private void OnCollisionEnter2D(Collision2D other)
    {
        if (other.gameObject.CompareTag("Ground"))
        {
            isOnGrounded = true;
        }
    }
    private void OnCollisionExit2D(Collision2D other)
    {
        if (other.gameObject.CompareTag("Ground"))
        {
            isOnGrounded = false;
        }
    }
}

The problem is when the Player is standing on Platform01 so obviously isOnGrounded = true and when the Player moves out of Platform01 isOnGrounded = false, I suppose when move in Platform02 it will automatically check the Ground and isOnGrounded = true but it still false and everything just messing up.

CodePudding user response：

This is because OnCollisionEnter2D(Platform02) is triggered before OnCollisionExit2D(Platform01).

You can remember the last hit collider and compare with it when leave a platform.

public class PlayerController : MonoBehaviour
{
    private Collision2D ground;
    public bool IsGround => (bool)ground;

    private void OnCollisionEnter2D(Collision2D other)
    {
        if (other.gameObject.CompareTag("Ground"))
        {
            ground = other;
        }
    }
    private void OnCollisionExit2D(Collision2D other)
    {
        if (other.gameObject.CompareTag("Ground") && other == ground)
        {
            ground = null;
        }
    }
}