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. 20, 2006
Filed:
Oct. 14, 1998
Ronald D. Larson, Fort Collins, CO (US);
Ronald D. Larson, Fort Collins, CO (US);
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Abstract
A multi-function unit for occlusion testing primitives being processed in a graphics system and for updating a Z pyramid data structure used for occlusion testing. The Z pyramid data structure is updated on the fly, i.e., as primitives are being occlusion tested. The apparatus comprises multi-function unit is configured to create the Z pyramid data structure and to perform occlusion testing. The Z pyramid data structure comprises a plurality of levels, each of which comprises a plurality of regions. Each region comprises a plurality of subregions, each of which corresponds to a single Z value. Each region corresponds to a plurality of Z values and has a maximum region Z value, which corresponds to the largest Z value of the region. The multi-function unit compares the minimum Z value of each primitive with the maximum Z value of a region associated with the tested primitive to determine whether or not the tested primitive is fully occluded. Coverage masks are maintained by the multi-function unit for the different levels of the Z pyramid data structure to enable the Z pyramid data structure to be updated on the fly. When certain bits in the coverage masks are set, the multi-function unit causes the Z pyramid data structure to be updated.