Picking function for a pipeline graphics system using hierarchical graphics structures

摘要: A graphics display system picking function tracks machine states of pickable primitive operators through the use a pick stack and state memory. The operates as when accessed by pipeline processors. Pipeline processors can add an element to or remove elements from structures are processed. Selection object causes control processor randomly access determine attributes picked primitive. memory is implemented video RAM allowing rapid copying rows containing for various structure levels in hierarchy. first area stores relating hierarchy they executed. second retains abbreviated description each while final contains information objects be echoed system. memories operate together provide identification, echoing. separate echo storage allows drawing primitives without complete re-traversal displayed list. This also results reduced processing time.