How to make player not able to move in direction of wall if he will collide with him on next step?

My goal is to make player not able to move in the direction of wall if he will collide with him on next step(for example if player presses “A”, and with this press he will collide with the wall, nothing will happend, but he will be able to move forward with “W” if next step is not colliding with the wall and so on.

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

public class PlayerController : MonoBehaviour
{

    public bool smoothTransition = false;
    public float transitionSpeed = 10f;
    public float transitionRotationSpeed = 500f;

    Vector3 targetGridPos;
    Vector3 prevTargetGridPos;
    Vector3 targetRotation;

    private void Start()
    {
        targetGridPos = Vector3Int.RoundToInt(transform.position);
        Collider collider = gameObject.AddComponent<BoxCollider>();
        collider.isTrigger = false;
    }

    private void FixedUpdate()
    {
        MovePlayer();
    }

    void MovePlayer()
    {
        if (true) // here is an error?
        {
            prevTargetGridPos = targetGridPos;

            Vector3 targetPosition = targetGridPos;

            if (targetRotation.y > 270f && targetRotation.y < 361f) targetRotation.y = 0f;
            if (targetRotation.y < 0f) targetRotation.y = 270f;

            if (!smoothTransition)
            {
                transform.position = targetPosition;
                transform.rotation = Quaternion.Euler(targetRotation);
            }
            else
            {
                transform.position = Vector3.MoveTowards(transform.position, targetPosition, Time.deltaTime * transitionSpeed);
                transform.rotation = Quaternion.RotateTowards(transform.rotation, Quaternion.Euler(targetRotation), Time.deltaTime * transitionRotationSpeed);
            }

            // Check for collisions with walls
            Collider[] hitColliders = Physics.OverlapSphere(transform.position, 0.4f);
            foreach (Collider hitCollider in hitColliders)
            {
                Debug.Log("Collided with " + hitCollider.gameObject.name);

                if (hitCollider.gameObject.CompareTag("Wall"))
                {
                    targetGridPos = prevTargetGridPos; // move the player back to their previous position
                    break;
                }
            }
        }
        else
        {
            targetGridPos = prevTargetGridPos;
        }
    }

    void OnCollisionEnter(Collision collision)
    {
        // Check if the collision is with a wall
        if (collision.gameObject.tag == "Wall")
        {
            // Move the player back to their previous position
            targetGridPos = prevTargetGridPos;
        }
    }


    public void RotateLeft() { if (AtRest) targetRotation -= Vector3.up * 90f; }
    public void RotateRight() { if (AtRest) targetRotation += Vector3.up * 90f; }
    public void MoveForward() { if (AtRest) targetGridPos += 2 * transform.forward; }
    public void MoveBackward() { if (AtRest) targetGridPos -= 2 * transform.forward; }
    public void MoveLeft() { if (AtRest) targetGridPos -= transform.right; }
    public void MoveRight() { if (AtRest) targetGridPos += transform.right; }


    bool AtRest
    {
        get
        {


            if ((Vector3.Distance(transform.position, targetGridPos) < 0.05f) &&
                (Vector3.Distance(transform.eulerAngles, targetRotation) < 0.05f))
                return true;
            else
                return false;
        }
    }
}

You’ve already identified the parts / steps of what you want, now implement them:

  • read the user intention (“I want to go right!”)
  • check the world or map or tiles or whatever you have that defines your player space
    → if they can move, move them
    → if they cannot move, ignore the intention

If you’re having difficulty, here is how to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

This is the bare minimum of information to report:

  • what you want
  • what you tried
  • what you expected to happen
    - what actually happened, especially any errors you see
    - links to documentation you used to cross-check your work (CRITICAL!!!)

If you have no idea what your code is doing, fix that first. Here’s how:

You must find a way to get the information you need in order to reason about what the problem is.

Once you understand what the problem is, you may begin to reason about a solution to the problem.

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is
  • you’re getting an error or warning and you haven’t noticed it in the console window

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer or iOS: How To - Capturing Device Logs on iOS or this answer for Android: How To - Capturing Device Logs on Android

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

When in doubt, print it out!™

Note: the print() function is an alias for Debug.Log() provided by the MonoBehaviour class.