METHOD FOR CONTROLLING THE PRESENTATION OF NESTED OVERLAYS

摘要

A method is disclosed for controlling the presentation of nested overlays on a display medium. An overlay function resource is provided which includes its own environment specification which is independent of the space and data environment specifications. Mixing attributes are associated with each overlay and are utilized to determine which overlay space and data are to take precedence and be visible when the overlayed spaces are combined and imaged on a display medium. In a preferred mode of the present invention, the foreground and background of each overlay are separately controlled by the mixing attributes which define the mixing rules for the layered presentation of multiple overlays. Additionally, the order of precedence for displaying multiple overlays may be selectively altered or varied to provide multiple displays and to permit an individual overlay to be repetitively utilized.