How do I invert mouse movement for a specific section of my game?

Questions & Answers
1

Hello! Newcomer to Unity here, seeking some advise!

Ok, so I have this 2D top-down shooter, where I have a script attached to a crosshair object. On Update, this crosshair will move according to Input.mousePosition, hence if my cursor moves, so does this crosshair.

I have this special level where I wish to invert the mouse input, so players will have to aim with everything reversed. Here’s the code on my crosshair:

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

public class Crosshair : MonoBehaviour
{
    // Use this for initialization
    void Start ()
    {
        //Hide mouse cursor
        Cursor.visible = false;
	}
	
	// Update is called once per frame
	void Update ()
    {
        transform.position = Input.mousePosition;
	}
}

Does Unity have a way to invert mouse input for a single level? Or is there anything I could do to achieve this? If I move to the next level, the mouse input should return to normal.

Thanks!

5

Hey guys don’t you even math?
@deadsea2004 Use this one to get reversed position and assign it to cursor’s transform position like this

transform.position=Reverseposition(input.mouseposition);

Vector2 ReversePosition(Vector2 uipos)
{
    uipos.x = Screen.width - uipos.x;
    uipos.y = Screen.height - uipos.y;
    return uipos;
}
2

You should reverse it manually like this.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Crosshair : MonoBehaviour
 {
     isInverted = false;

     // Use this for initialization
     void Start ()
     {
         //Hide mouse cursor
         Cursor.visible = false;
     }
     
     // Update is called once per frame
     void Update ()
     {
        if(isInverted)
        {
            transform.position = -Input.mousePosition;
         
        }
        else
        {
            transform.position = Input.mousePosition;
        }
     }
 }

if you change isInverted variable to true somewhere in game, it will work.

3

I would suggest you go about it something like this:

using UnityEngine;
using UnityEngine.SceneManagement;

 public class Crosshair : MonoBehaviour
 {
     private bool reverseLevel = false;

     // Use this for initialization
     void Start ()
     {
         //Hide mouse cursor
         Cursor.visible = false;

	      if(SceneManager.GetActiveScene().name == " scene name where it reverses")
	      {
                 reverseLevel = true;
          }
     }
    
     void Update()
     {
        if(reverseLevel)
        {
             transform.positon =  ReverseCrossHair(Input.position);
        }
        else transform.position = Input.position;
     }

         public Vector2 ReverseCrossHair(Vector2 pos)
     {
           return -pos;
     }
    

}

The best way I can see you reversing your crosshairs is by multiplying it by -1 since this reverses the coordinates.

Edit: You can just copy paste this code and it should work. Since we change the bool to true only at the level you want, this code can still be reused for your other levels.

4

Hm, if I multiply Input.mousePosition by -1, this causes my Crosshair image to vanish for some reason. I’m assuming it went off-screen?