CameraRotation

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

public class MouseLook : MonoBehaviour
{
   public enum RotationAxes
   {
        MouseXAndY = 0,
        MouseX = 1,
        MouseY = 2
   }
   public RotationAxes axes = RotationAxes.MouseXAndY;
   public float SensitivityHor = 9.0f;
   public float SensitivityVer = 9.0f;

   public float minimumVert = -45.0f;
   public float maximumVert = 45.0f;

   private float _rotationX = 0;

    void Start()
    {
        Rigidbody body = GetComponent<Rigidbody>();
        if (body != null)
        {
            body.freezeRotation = true;
        }
    }

    // Update is called once per frame
    void Update()
    {
        if (axes == RotationAxes.MouseX)
        {
            transform.Rotate(0, Input.GetAxis("Mouse X") * SensitivityHor,0);
        }
        else if (axes == RotationAxes.MouseY)
        {
            _rotationX -= Input.GetAxis("Mouse Y") * SensitivityVer;
            _rotationX = Mathf.Clamp(_rotationX, minimumVert, maximumVert);
            float rotationY = transform.localEulerAngles.y;
            transform.localEulerAngles = new Vector3(_rotationX, rotationY, 0);
        }
        else
        {
            _rotationX -= Input.GetAxis("Mouse Y") * SensitivityVer;
            _rotationX = Mathf.Clamp(_rotationX, minimumVert, maximumVert);

            float delta = Input.GetAxis("Mouse X") * SensitivityHor;
            float rotationY = transform.localEulerAngles.y + delta;

            transform.localEulerAngles = new Vector3(_rotationX, rotationY, 0);
        }
    }
}