Patent · US Expired

Depth buffer clipping for window management

US5241656A · kind A · utility

56Cited by
9References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 13, 1991
Grant dateAug 31, 1993
Priority date
Expiry dateDec 13, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F3/0481
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

In a computer system with a screen display on which is formed a plurality of at least partially overlapping windows associated with different applications, a depth buffer is added to the display adapter for providing with different applications, a depth buffer is added to the display adapter for providing clipping assistance to the software-based window manager. A refresh buffer stores pixel data for each pixel of the display. The window manager monitors the current depth position of each of the pixels within the display and generates a depth value for each pixel. In response to an input request for window rearrangement, the window manager assigns a new depth value to each pixel in a window affected by the request, requests that each application affected by the rearrangement to retransmit pixel values for the pixels associated with at least the portion of a affected window which will become visible as a result of the rearrangement, and transmits new depth values for at least the pixels within the affected portions of such windows. The depth buffer receives and compares the new depth values with the current depth value for each pixel. If the comparator determines that the new pixel …

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