The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 13, 1991
Filed:
May. 07, 1990
Fu-Chung Chang, Rhinebeck, NY (US);
James A Donnelly, West Hurley, NY (US);
Richard A Marino, Kingston, NY (US);
Terence W Lindgren, Littleton, MA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for clipping a line segment boundary-defined area against a limiting plane is disclosed for use in a computer graphics display system wherein graphics figures are represented by random sets of polylines definitive of line segment boundary-defined areas. Pursuant to the clipping method, once two intersection points are generated against one plane, the points are connected to form an edge of the new clipped boundary-defined area. The order of intersection point connection is irrelevant to the invention and the method can accomodate discontinuously presented data as readily as continuously presented data. Implementing the method essentially requires only one register to store the first intersection point and a flag register to indicate the status of the present clip point, i.e., whether the clipped point is the first or second of two points to be paired. In another aspect of the invention, an improved extraneous edge deletion method is provided capable of deleting extraneous lines formed as a result of a line segment boundary-defined area being clipped against a limiting plane. Pursuant to the method, clipped X-axis and Y-axis extraneous edges are eliminated during area fill processing in the graphics display system.