19. The apparatus of claim 18 , wherein the set of instructions for identifying overlapping primitive graphic elements as subsets of primitive graphic elements comprises sets of instructions for: selecting a first graphic element in the set and assigning the graphic element to a new subset; assigning a second graphic element in the set to the new subset when a bounding box of the second graphic element overlaps a bounding box of the new subset.
19. The apparatus of claim 18 , wherein the set of instructions for identifying overlapping primitive graphic elements as subsets of primitive graphic elements comprises sets of instructions for: selecting a first graphic element in the set and assigning the graphic element to a new subset; assigning a second graphic element in the set to the new subset when a bounding box of the second graphic element overlaps a bounding box of the new subset. 20. The apparatus of claim 19 , wherein the new subset is a first subset, wherein the set of instructions for identifying overlapping primitive graphic elements as subsets of primitive graphic elements further comprises a set of instructions for assigning a third graphic element to a second subset when a bounding box of the third graphic element does not overlap the bounding box of the first subset.