A method of associating a shared fill with a plurality of objects, is disclosed. Each of the objects is associated with a fill. A bounding region of the shared fill is determined based on a fill of a first of the plurality of objects. The first object is associated with the shared fill. A second object is received and the shared fill is updated based on a fill of the second object if: (a) the fill of the second object is contained within the bounding region; and (b) the fill of the second object is non-overlapping with the fill of the first object. The second object is associated with the updated intermediate fill. The updated shared fill is shared by the first object and the second object.