MIRROR-The-Mobius-Line/Assets/Scripts/GravityController.cs

using UnityEngine;

public class GravityController
{
    // The only instance of the class
    static GravityController s_Instance = null;

    // Constant gravity scale
    const float m_GravityScale = -20.0f;

    Vector3 m_Up = Vector3.zero;

    public static Vector3 up => s_Instance.m_Up;

    // Private constructor to stop accidental creation
    private GravityController() { }

    public static GravityController Instance()
    {
        // Creates an instance if there is not already one
        if (s_Instance == null)
        {
            s_Instance = new GravityController();
        }

        // Returns the instance
        return s_Instance;
    }

    public void SetScale(float scale)
    {
        // Sets the gravity
        Physics.gravity = new Vector3(0, m_GravityScale * scale, 0);
        m_Up = Physics.gravity;
    }
}