1. An object-oriented method for scan converting a closed geometric figure having a plurality of edges into a plurality of scan line pixels, the method operating in a computer system having a memory, wherein the geometric figure is represented by a graphic object which is comprised of data describing the plurality of edges and an object function for traversing the plurality of edges to outline the figure, the method comprising the steps of: (a) loading the graphic object into the memory; (b) creating a plurality of edge objects each of which edge objects comprises edge data describing a predetermined edge shape and an edge function for moving along the predetermined edge shape, utilizing the steps of: (b1) selecting a single name for the plurality of edge objects; (b2) assigning the selected name to each of the plurality of edge objects; and (b3) assigning different parameters to each of the plurality of edge objects; (c) accessing the graphic object and utilizing the data and the object function therein to select ones of the plurality of edge objects to represent the edges; (d) creating an edge engine object comprising a plurality of scan line functions for identifying portions of scan lines which lie within the geometric figure and on the edges; and (e) using the edge engine object scan line functions and the selected ones of the plurality of edge objects to generate a plurality of scan line pixels corresponding to identified portions of scan lines.