Patent · US Expired

Method and apparatus for determining line positions for display and manipulation by a computer system

US5128872A · kind A · utility

11Cited by
7References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 25, 1990
Grant dateJul 7, 1992
Priority date
Expiry dateOct 25, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G5/393
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A circuit for determining the X values of each end of a series of horizontal scan lines connecting a pair of line segments each of which is defined by a pair of vertices, the horizontal scan lines defining an area to be rendered on a computer output device, comprising first and second circuit portions, each of said circuit portions including apparatus to determine the slope of a line segment, apparatus depending on the slope for determining the beginning and ending X values for each line segment for each scan line in the area to be rendered, apparatus for causing the two circuit portions to begin operation at the same scan line, and apparatus for changing the Y value for each circuit portion to the Y value of the next adjacent scan line at the same time.

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