Abstract: The present invention discloses a method, apparatus, and article of manufacture for converting Non-Zero Winding to Even-Odd rule polygons, regardless of their shapes. Convex, concave, self-intersecting, and polygons with holes can all be converted from Non-Zero Winding to Even-Odd fill rule polygons. The invention accepts Non-Zero Winding fill polygons and computes all intersection points between the polygons. An initial intersection point between a first polygon and a second polygon is selected. The perimeter of either the first or second polygon is traced beginning from the selected intersection point. The trace switches between the perimeters of the first and second polygons as additional intersection points are reached during the tracing. The tracing is terminated when the selected intersection point is encountered by the tracing step. These steps are then repeated until all intersection points between the first and second polygons have been encountered.

Abstract: The present invention discloses an apparatus, method, and article of manufacture for generating graphic images. In accordance with the present invention, an application program receives commands from a computer user via an input device and provides an output command stream to a plurality of renderer programs. The renderer programs selectively modify the output command stream and transmit the output command stream to a graphics peripheral device or to one or more of the other renderer programs.

Abstract: An apparatus, method, and article of manufacture for providing compatibility between an application program and a renderer executing on a computer. An application program, executed by the computer, receives commands from a user via the input device and generates an output command stream in response thereto, wherein the output command stream comprises one or more instructions for generating the graphic images. A version renderer program, executed by the computer and coupled to the application program, translates the output command stream received from the application program into a renderer command stream. One or more renderer programs, executed by the computer and coupled to the version renderer program, receive the renderer command stream from the version renderer program, selectively modify the renderer command stream, and selectively transmit the renderer command stream to the graphics peripheral device or to one or more of the other renderer programs.

Abstract: A method, apparatus, and article of manufacture for performing a polygon set operation on two or more polygons. A trace direction is determined based on the polygonal set operation, and an initial intersection point between first and second polygons is selected. The perimeter of either the first or second polygons is traced beginning from the selected intersection point and continuing in the determined trace direction. The trace switches between the perimeters of the first and second polygons as additional intersection points are reached during the tracing. The tracing is terminated when the selected intersection point is encountered by the tracing step. These steps are then repeated until all intersection points between the first and second polygons have been encountered.

Abstract: The present invention discloses a method, apparatus, and article of manufacture for compressing vector data. The vector data is normalized to create normalized vector data. A history buffer is searched for a longest matching vector data that matches the normalized vector data. The longest matching vector data is encoded by assigning a substitution code. The vector data is normalized by translating the vector data to an origin and scaling the vector data to a unit square. The substitution code includes a denormalization function, which converts the normalized vector data to vector data.