Browse Prior Art Database

Method for Optimization and Multiple Screen Update Avoidance in Computer-Driven Video Displays

IP.com Disclosure Number: IPCOM000038353D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Rhyne, JR: AUTHOR

Abstract

The disclosed invention relates to a multi-phase method for processing a list of changes (edit operations) to a hierarchical graphical data structure as an interpretive aid in the creation or modification of the data structure for display purposes. A hierarchical data structure includes a set of values and associated pointers defining a tree graph.

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Method for Optimization and Multiple Screen Update Avoidance in Computer-Driven Video Displays

The disclosed invention relates to a multi-phase method for processing a list of changes (edit operations) to a hierarchical graphical data structure as an interpretive aid in the creation or modification of the data structure for display purposes. A hierarchical data structure includes a set of values and associated pointers defining a tree graph. The method steps include: (a) creating an auxiliary list characterizing each item in the change list as being in an update or recompute phase; (b) updating the data structure by value replacement and by insertion of marks at predetermined nodes (nodes affected by edit ops) as indexed by the auxiliary list characterization in synchronism with the change list in one or more passes therethrough; (c) recomputing those values in the data structure associated with marked nodes having no marked ancestors and removing the marks. In performing a recomputation for a given edit op, there exists three possible states. These are: (1) The node whose value has been updated is NOT marked. This means that some previous edit operation has performed the computation at this node.
(2) The node is marked and has a marked ancestor. Consequently, there is a subsequent edit op which in its recomputation phase will recompute the value at this node. (3) The node is marked and has no marked ancestor. This requires that recomputation must be carried out ...