public void MouseMoved( SharpInputSystem.MouseEventArgs evt )
{
if ( ( SelectionMode == SelectionModeType.SelectionBox ) && Selecting == true )
{
_stop = new Vector2( evt.State.X.Absolute / (float)_Camera.Viewport.ActualWidth, evt.State.Y.Absolute / (float)_Camera.Viewport.ActualHeight );
_rect.SetCorners( _start, _stop );
}
}