DISPLAY LIST WITH CROSSING QUEUES

A raster type printer that utilizes a display list and crossing queues to represent the primitive objects of a page image formed of dots on an array of pixels logically organized in a sequence of adjacent swaths each swath having a first boundary that is adjacent a prior in sequence swath, if any, and a second boundary that is adjacent a next in sequence swath, if any, wherein the display list contains for each swath a swath data list that includes object records for each primitive object included in the swath, wherein an object record for a primitive object is comprised of (1) an encoded description of the primitive object if the primitive object does not cross the first boundary of the swath, or (2) a crossing queue flag if the primitive object crosses the first boundary of the swath, and wherein the records in each swath data list correspond to a predetermined sequence of primitive objects on a page image. In the course of generating the bit map for a swath, an output crossing queue is utilized for storing remainder object records for objects that cross the second boundary of the swath, while an input crossing queue is utilized to provide remainder object records for objects that cross the first boundary of a swath. In particular, records are inserted into the output crossing queue in the course of rendering a bit map for a swath, and the output crossing queue for a swath is utilized as the input crossing queue in the course of rendering the bit map for the next in sequence swath.