Lock rotation with mouse drag

Unity Engine
1

hi.
I have a code like this that rotates the camera:

if (Input.GetMouseButtonDown(0))
{
      prevMousePos = cam.ScreenToViewportPoint(Input.mousePosition);
}

if (Input.GetMouseButton(0) )
{
     Vector3 direction = prevMousePos - cam.ScreenToViewportPoint(Input.mousePosition);

     camRotate.transform.Rotate(new Vector3(1, 0, 0), direction.y * 180);
     camRotate.transform.Rotate(new Vector3(0, 1, 0), -direction.x * 180, Space.World);

      prevMousePos = cam.ScreenToViewportPoint(Input.mousePosition);
}

and it works great, but how do I constrain the x-axis rotation? if I try to take a rotation like this

this.transform.rotation.eulerAngles.x

then the return value does not match the one in the inspector (matches only from 0 to 90 degrees, and after 90 it starts to go down again and it turns out that this function returns 50 if both 50 and 120 degrees are in the inspector). I want to make it impossible to make a full turn

2

So, what I would do is just clamp the prevMousePos you have already in your code.

Unity calculates rotations using Quaternions, which is usually hard to understand for humans, but translates it into Euler angles for readability.