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. 11, 1998
Filed:
Dec. 19, 1995
Theodore G Rossin, Ft. Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
Extra hardware to compute the fifth vertex of a bow-tie quadrilateral is avoided by using the clipping system to do the calculations. This is accomplished by inspecting quadrilaterals (as they are projected onto the viewing plane) to see if they contain pairs of self-intersecting sides. Those that do are further classified as to type and subtype, depending respectively upon how the vertex numbering scheme identifies the intersecting non-adjacent sides and upon which of X and Y is the major axis. The hardware normally associated with a clipper can be 'borrowed' and used in a non-clipping fashion to find the X coordinate for a YZ work plane (or the Y coordinate for an XZ work plane) that is associated with the fifth vertex (V.sub.4) created by the self-intersection. Once this is done the hardware of the clipper can be further borrowed to actually intersect (i.e., clip) one of the self-intersecting sides with that work plane, which produces a complete description of all the pixel coordinates for V.sub.4. Once V.sub.4 is known the bow-tie is divided into two triangles, each containing two adjacent vertices not found in the other triangle and each also containing V4 as a common vertex.