Path to trapezoid decomposition of polygons for printing files in a page description language

Abstract

This invention cures many inefficiencies with known scan conversion methods. This invention employs an edge array rather than a set linked list from an array of pointers equal in number to the number of scan lines. This invention thus eliminates storage of linked list pointers which in the prior art included many null pointers resulting in better memory utilization. This invention sorts the active edge table only at edge intersections and vertices, thus eliminating much unneeded sorting. This invention permits integrated clipping of a subject polygon by a clip polygon and forming trapezoids filling the clipped area by activating trapezoid formation at every vertex of either polygon and at every edge intersection. This process saves code space and computer processing time. This invention efficiently utilizes the resources of a multiprocessor integrated circuit by spawning of subtasks from a RISC type processor to one or more DSP type processors.