公开(公告)号：CA2127370C

公开(公告)日：1999-02-23

申请号：CA2127370

申请日：1993-01-13

Applicant: COMPAQ COMPUTER CORP

Inventor： ALBERS THOMAS MICHAEL ,  EBERST JOHN VERNON ,  FONTENOT DARWIN ,  PYRA RICHARD LYNN ,  WELKER MARK WILLIAM ,  WOOD PAUL BERTON ,  BRESENHAM JACK E

IPC: G09G5/20 ,  G06T11/20 ,  G06F3/14

Abstract: Line draw circuitry receives parameters defining first and second endpoints of a line and calculates line parameters based on the first and second endpoints. The line parameters may be modified prior to drawing a line based on the calculated and modified parameters.

公开(公告)号：CA2127369C

公开(公告)日：1999-02-23

申请号：CA2127369

申请日：1993-01-13

Applicant: COMPAQ COMPUTER CORP

Inventor： ALBERS THOMAS MICHAEL ,  EBERST JOHN VERNON ,  FONTENOT DARWIN ,  WOOD PAUL BERTON ,  PYRA RICHARD LYNN ,  WELKER MARK WILLIAM ,  BRESENHAM JACK E

IPC: G09G5/20 ,  G06T11/20 ,  G06F3/14

Abstract: Circuitry for drawing lines includes a video memory for storing pixel data and c ircuitry for generating a sequence of addresses defining a line of pixels in the video memory. A first memory stores a sequence of pattern units corresponding to the generated sequence of addresses. A second memory stores a value indicating a cur rent pattern unit. Writing circuitry writes to the video memory at a generated address responsive to a current pattern unit. A thir d memory stores a control value which is accessed by update circuitry for updating the second memory to indicate the next pattern unit. The update circuitry may selectively update the second memory to the sequential pattern unit or reset the second memo ry to a predetermined pattern unit.