UnityEditor.Tools.GetRectRotationForAxis C# (CSharp) Method

        private static Quaternion GetRectRotationForAxis(Quaternion rotation, int axis)
        {
            switch (axis)
            {
                case 0:
                    return (rotation * Quaternion.Euler(0f, 90f, 0f));

                case 1:
                    return (rotation * Quaternion.Euler(-90f, 0f, 0f));

                case 2:
                    return rotation;
            }
            return rotation;
        }