The routines that DrawObjectsInList runs to decide which of two objects to draw first, chosen by the relation between them. The relation is made from the relation along the X axis (0 to 2) and three times the relation along the Y axis (0 to 2), and nine is added to it when the view is rotated. The routine is KeepObject if the first object stays, ChooseOtherObject if the second object is chosen, and CompareObjectDepths if they have to be compared further.