Method and apparatus for handling secondary dependencies

Abstract

A method and apparatus for creating a series of images is disclosed. The method manages secondary dependencies of regions in a more efficient manner than the prior art. The present invention creates contents labels that represent either leaf node regions or the composition of two other contents labels, manages the reference counting of contents labels and provides a means for determining if there exists a contents label which represents the composition of two other contents labels. The present invention damages contents labels by preferably adding entries to a damage hash table. The present invention utilizes secondary dependency “Directed Acyclic Graphs” (herein referred to as “Dags”) ( ) which are stored in every binary node and define the secondary dependency relationship between the contents label created in that node. Information is provided by the present invention as to whether a contents label which has the potential to come into existence is damaged in any way, via examination of secondary dependency Dags associated with the contents label. Information is also provided on whether rendering can be avoided by determining the properties of particular compositing operators involved in a rendering operation.