Apparatus and method for managing the assignment of display attribute identification values and multiple hardware color look-up tables
US5430465A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1994 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Mar 29, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/14
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a bit mapped display environment which has n hardware color look-up tables (CLUTs) where n=1 or more, which also has a limited number of Display Attribute Identification Values, and which may operate under various window systems, such as the X Window System protocol, an apparatus and a method for installing and uninstalling hardware colormaps under the constraint of a finite number of Display Attribute Identification Values, whereby the most recently installed (MRI) policy of the X Window System is followed. The invention provides a scheme which gracefully degenerates to some "color flashing" when Display Attribute Identification Values are exhausted; which allows Display Attribute Identification Values to be uncoupled from colormap management and used for more graphics intensive functions when needed; and which dynamically regenerates when display attributes again become available. The invention also minimizes the rendering of the Display Attribute Planes when a new colormap is installed in a system containing multiple hardware color look-up tables.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.