The mouse position relative to the previous position (position at the last frame).
Note: Since InputEventMouseMotion is only emitted when the mouse moves, the last event won't have a relative position of Vector2(0, 0) when the user stops moving the mouse.
The mouse position relative to the previous position (position at the last frame). Note: Since InputEventMouseMotion is only emitted when the mouse moves, the last event won't have a relative position of Vector2(0, 0) when the user stops moving the mouse.