公开(公告)号：DE3379004D1

公开(公告)日：1989-02-23

申请号：DE3379004

申请日：1983-06-30

Applicant: IBM

Inventor： BRESENHAM JACK E ,  BOWATER RONALD J ,  GAY ADRIAN C ,  SHEEN NORMAN R

IPC: G09G5/32 ,  G09G1/10 ,  G09G5/24 ,  G09G1/16

公开(公告)号：CA1224290A

公开(公告)日：1987-07-14

申请号：CA455228

申请日：1984-05-25

Applicant: IBM

Inventor： BRESENHAM JACK E ,  BOWATER RONALD J ,  GAY ADRIAN C ,  SHEEN NORMAN R

IPC: G09G5/32 ,  G09G1/10 ,  G09G5/24 ,  G09G1/16

Abstract: METHOD OF STORING CHARACTERS IN A DISPLAY SYSTEM In a method of storing characters in a display system having a display device with an orthogonal matrix of addressable points, each character is represented as a succession of strokes each constrained to lie in one of the eight fundamental directions of the matrix and, except for the first stroke, each starting at the end of the previous stroke. Each such stroke is stored in a binary coded form which includes a first binary number (direction code) defining the angular direction of the stroke, a second binary number (length code) defining a number of matrix steps from one addressable point to the next along the stroke in that direction, and a third binary number (move/draw code) defining the visibility of the stroke. In order to facilitate character rotation by any multiple of 45.degree. the direction code defining each fundamental direction corresponds to the addition modulo 2n of a binary constant to the direction code which defines the fundamental direction at 45.degree. thereto in a given direction of rotation, where n is the number of bits in the direction code.