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:
Jun. 16, 1998
Filed:
Sep. 28, 1995
Theodore G Rossin, Fort Collins, CO (US);
Alan S Krech, Jr, Fort Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A hardware graphics accelerator accepts lists of polygon vertices from an application environment running application and systems graphics software. After a polygon is rotated and translated as needed, it is checked for trivial accept/reject against the clip limits of the viewing volume, but is not otherwise clipped. Polygons that are not rejected are decomposed into triangles before any other operations on them are performed. After decomposition the triangles are illuminated by light sources, if desired and then clipped by a triangle clipper, rasterized, and the results sent to a frame buffer for display. The triangle clipper incorporates trivial accept/reject operation, and is capable of operating on non-planar quadrilaterals. It avoids ugly artifacts during certain clip operations when the diagonal used to decompose a quadrilateral into triangles intersects a clip plane not parallel to the viewing axis. It does this by replacing the point of intersection along that diagonal that the clipper would ordinarily find with a point that is the projection of that diagonal onto a line between two adjacent points of intersection of the actual edges of the quadrilateral with the clip plane.