Patent · US Expired

Method and apparatus for pixel clipping source and destination windows in a graphics system

US5193148A · kind A · utility

20Cited by
7References
28Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 4, 1991
Grant dateMar 9, 1993
Priority date
Expiry dateDec 4, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G5/14
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A method of moving blocks of pixel data, including window-identifying data, from a source area to a destination area within a frame buffer in a computer graphics system comprises the steps of: reading a block of pixel data from the source area into a pixel cache memory; combining source tiles with destination tiles in the cache; comparing pixel window identifiers read from the frame buffer with a pixel window identifier previously stored in the memory to determine whether the pixel window identifiers read from the frame buffer match the previously stored pixel window identifier; discarding each pixel whose corresponding window identifier does not match the previously stored window identifier; and updating the frame buffer with the pixel data not discarded.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.