UnityEditor.SceneViewMotion.OrbitCameraBehavior C# (CSharp) Method

        private static void OrbitCameraBehavior(SceneView view)
        {
            Event current = Event.current;
            view.FixNegativeSize();
            Quaternion target = view.m_Rotation.target;
            target = Quaternion.AngleAxis((current.delta.y * 0.003f) * 57.29578f, (Vector3) (target * Vector3.right)) * target;
            target = Quaternion.AngleAxis((current.delta.x * 0.003f) * 57.29578f, Vector3.up) * target;
            if (view.size < 0f)
            {
                view.pivot = view.camera.transform.position;
                view.size = 0f;
            }
            view.rotation = target;
        }

        private static void HandleMouseDrag(SceneView view, int id)
        {
            SceneViewMotion.s_CurrentState = SceneViewMotion.MotionState.kDragging;
            if (GUIUtility.hotControl == id)
            {
                Event current = Event.current;
                switch (Tools.s_LockedViewTool)
                {
                case ViewTool.Orbit:
                    if (!view.in2DMode && !view.isRotationLocked)
                    {
                        SceneViewMotion.OrbitCameraBehavior(view);
                        view.svRot.UpdateGizmoLabel(view, view.rotation * Vector3.forward, view.m_Ortho.target);
                    }
                    break;

                case ViewTool.Pan:
                {
                    view.viewIsLockedToObject = false;
                    view.FixNegativeSize();
                    Camera  camera = view.camera;
                    Vector3 vector = camera.WorldToScreenPoint(view.pivot);
                    vector += new Vector3(-Event.current.delta.x, Event.current.delta.y, 0f);
                    Vector3 vector2 = Camera.current.ScreenToWorldPoint(vector) - view.pivot;
                    vector2 *= EditorGUIUtility.pixelsPerPoint;
                    if (current.shift)
                    {
                        vector2 *= 4f;
                    }
                    view.pivot += vector2;
                    break;
                }

                case ViewTool.Zoom:
                {
                    float num = HandleUtility.niceMouseDeltaZoom * (float)((!current.shift) ? 3 : 9);
                    if (view.orthographic)
                    {
                        view.size = Mathf.Max(0.0001f, view.size * (1f + num * 0.001f));
                    }
                    else
                    {
                        SceneViewMotion.s_TotalMotion += num;
                        if (SceneViewMotion.s_TotalMotion < 0f)
                        {
                            view.size = SceneViewMotion.s_StartZoom * (1f + SceneViewMotion.s_TotalMotion * 0.001f);
                        }
                        else
                        {
                            view.size += num * SceneViewMotion.s_ZoomSpeed * 0.003f;
                        }
                    }
                    break;
                }

                case ViewTool.FPS:
                    if (!view.in2DMode && !view.isRotationLocked)
                    {
                        if (!view.orthographic)
                        {
                            view.viewIsLockedToObject = false;
                            Vector3    a          = view.pivot - view.rotation * Vector3.forward * view.cameraDistance;
                            Quaternion quaternion = view.rotation;
                            quaternion    = Quaternion.AngleAxis(current.delta.y * 0.003f * 57.29578f, quaternion * Vector3.right) * quaternion;
                            quaternion    = Quaternion.AngleAxis(current.delta.x * 0.003f * 57.29578f, Vector3.up) * quaternion;
                            view.rotation = quaternion;
                            view.pivot    = a + quaternion * Vector3.forward * view.cameraDistance;
                        }
                        else
                        {
                            SceneViewMotion.OrbitCameraBehavior(view);
                        }
                        view.svRot.UpdateGizmoLabel(view, view.rotation * Vector3.forward, view.m_Ortho.target);
                    }
                    break;

                default:
                    Debug.Log("Enum value Tools.s_LockViewTool not handled");
                    break;
                }
                current.Use();
            }
        }