How to get position of next object that closest to player,when player is move forward to nearest every time?

Question

I have a scene that looks like the following picture:

The Player has a RigidBody2D and all the steps have a BoxCollider2D. All steps are tagged with a 'step' tag.

I would like to let the player move to the next step, every time the user presses a key. In this case, I'll need to get the position of the next step that is the closest to the player, every time the player moves to the next position.

I have tried the following so far:

using UnityEngine;
using System.Linq;

public class Box : MonoBehaviour
{
    //the rigidbody of the box 
    private Rigidbody2D player2D;

    // Start is called before the first frame update
    void Start()
    {
        player2D = GetComponent<Rigidbody2D>();
    }

    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            Vector2 targetPosition = GetNextTargetTransform(player2D.position );

            //here set trajectory to move from current position to target position 
            Vector2 trajectory = SetTrajectory(player2D, targetPosition); 
            player2D.AddForce(trajectory, ForceMode2D.Impulse);

            //after reach the position update player position to current position
            //player2D.position = targetPosition;
        }
    }

    public Vector2 GetNextTargetTransform(Vector2 player2Dposition)
    {
        GameObject[] step = GameObject.FindGameObjectsWithTag("step");

        //here is the code to get the nearest object using LinQ 
        var nearest = step.OrderBy(t => Vector2.Distance(player2Dposition, t.transform.position)).FirstOrDefault();

        Transform nearestPosition = nearest.transform;
        Vector2 targetPosition = new Vector2(nearestPosition.position.x, nearestPosition.position.y);

        return targetPosition;
    }
}

I am able to get the position of the first step when a button is pressed, but when I press the key again, I am unable to get the position of the next step (and thus remain on the first position).

I've added player2D.position = targetPosition; after AddForce(...) and the player will directly appear on the first step and move to the next one, which is not the result I want.

Question

How do I get the position of the nearest step, every time the player moves to a new step?

Answer 1

At the beginning of your game you could create a list of Steps (it would contain either the transforms or the colliders of all the steps of the scene). Every time the player presses down, you run through your list of Steps and try to find the closest one (using Vector3.Distance between player position and step position, it should be easy to determine the closest one). The trick here is to save what Step you're one. So every time the player jumps on a new step you save it as the current step in a variable contained on your player. Now everytime you want to find the closest step you run through your list of step comparing the distance of the player and excluding the one you have saved.