Method for generating stroke-vector characters for use in a display

Abstract

A novel method is disclosed for use in an electronic raster-scan display system, for generating characters using a stroke-vector technique. An incoming data signal defines the type of character to be displayed, the character field dimensions, the character drawing point, and any character rotation or reflection. Using that part of the data signal that defines the character type as a memory address, a character microprogram is retrieved containing a plurality of encoded binary valued stroke-drawing directives. These directives are instructions detailing how to generate all of the shape dependent attributes for a series of chain related stroke-vectors that define the overall shape of a character to be displayed. The encoded drawing directives are decoded and sequentially applied to a set of initial values that define an initial virtual stroke-vector, and thereby generating all of the character-shape dependent stroke attributes to for a series of chain related stroke-vectors that define a character shape. Once defined each stroke-vector is scaled so that the generated character cell size corresponds to the character field dimensions defined by the external data signal. Lastly a logical pel may be generated and added to the individual stroke-vectors before the connected stroke-vectors are projected onto the display screen at the character drawing point.