Test two approaches to implement dragging in CGE:

1. Just watch Motion events (e.g. by overriding TUIState.Motion), and subtract new mouse position - old mouse position.

   This is simple, and makes sense if

   • you leave the mouse cursor visible,
   • and the dragging area is naturally limited to the window.

   E.g. this makes sense when you implement drag-and-drop.

2. Use the same logic as MouseLook. In this case the mouse cursor should be hidden, and you use TUIContainer.MouseLookDelta and friends to

   • read mouse motion movement,
   • and keep the mouse position around the middle of the window (to pretend that the dragging area is infinite).

   This makes sense if you want the movement of something to not be limited by window borders.