Stroke-vector character generator

Claim 2

In an electronic graphic display system, a character generator for generating a series of signals for use in displaying characters on a display screen, said generator comprising: means for receiving a first data signal defining the character type to be displayed, the character field dimensions, and the character drawing point; first memory means for storing a plurality of encoded binary valued stroke-drawing directives for the particular character defined by said first data signal; second memory means for storing encoded initial values for each character-shape dependent stroke attribute, said initial values being independent of the character type; decoding means for receiving said encoded stroke-drawing directives corresponding to the character type specified by said first data signal and for receiving said encoded initial values, said decoding means decoding said encoded stroke-drawing directives and said encoded initial values and sequentially applying the decoded drawing directives to the decoded initial values thereby generating a series of stroke signals representing a series of interconnected stroke-vectors; scaling means for receiving said stroke signals and said first data signal, said scaling means generating a series of scaled stroke signals by scaling the length of each stroke-vector so that the character image is scaled to the character field dimensions defined by said first data signal; and conversion means converting said scaled stroke signals into a series of signals designating the start/stop position of each interconnected stroke-vector, said series of signals defining a character image for the character type defined by said first data signal.

Claim 3

A character generator as in claim 1 further comprising: pel-generator means receiving said series of signals, said means generating signals PELX-LENGTH and PELY-LENGTH corresponding to the X,Y dimensions of a logical pel, said pel-generator means also generating an output signal corresponding to the pixel location on said display screen of said series of signals with the logical-pel superimposed thereon.

Claim 4

A character generator as in claim 2 wherein said pel-generator means develops the signal PELX-LENGTH so that x-dimension of the logical-pel is equal to the x-dimension of each horizontal stroke-vector and also develops the signal PELY-LENGTH so that the y-dimension of the logical pel is equal to the y-dimension of each vertical stroke-vector.

Claim 5

A character generator as in claim 3 further comprising frame buffer means to store said output signal from said pel-generator means to enable the display system to repeatedly scan said frame buffer means to display the desired character.

Claim 6

A character generator as in claim 3 further comprising means for projecting onto said display screen at said character drawing point said character mask with the logical-pel superimposed thereon and thereby generating the desired character display.

Claim 7

A character generator as in claim 3 wherein said scaling means adjusts each horizontal stroke-vector to be uniform in length, adjusts each vertical stroke-vector to be uniform in length, and so that the horizontal stroke-vector span and the vertical stroke-vector span are equal to the respective character field dimensions specified by said first data signal.

Claim 8

A character generator as in claim 6 wherein said first memory means further comprises: means for decoding said first data signal to generate a character code output signal defining the character type; means for addressing a memory location in said first memory means using said character code output signal as a memory address; and means for reading out of said first memory means a plurality of encoded binary valued stroke-drawing directives.

Claim 9

In an electronic graphic display system, a character generator for generating a series of signals for use in displaying characters on a display screen, said generator comprising: means for receiving a first data signal defining the character type to be displayed, the character field dimensions, the character drawing point, and the character rotation; first memory means for storing a plurality of encoded binary valued stroke-drawing directives for the particular character defined by said first data signal; second memory means for storing encoded initial values for each character-shape dependent stroke attribute, said initial values being independent of the character type; logic means modifying selected encoded initial values in said second memory means based upon the character rotation; decoding means for receiving said encoded stroke-drawing directives corresponding to the character type specified by said first data signal and for receiving said encoded initial values, said decoding means decoding said encoded stroke-drawing directives and said encoded initial values and sequentially applying the decoded drawing directives to the decoded initial values thereby generating a series of stroke signals representing a series of interconnected stroke-vectors; scaling means for receiving said stroke signals and said first data signal, said scaling means setting the length of each stroke-vector so that the character image is scaled to the character field dimensions defined by said first data signal; and conversion means converting said stroke signals into a series of signals designating the start/stop position of each interconnected stroke-vector, said series of signals defining a character image for the character type defined by said first data signal.

Claim 10

In an electronic graphic display system, a character generator for generating a series of signals for use in displaying characters on a display screen, said generator comprising: means for receiving a first data signal defining the character type to be displayed, the character field dimensions, the character drawing point, and the character rotation; first memory means for storing a plurality of encoded binary valued stroke-drawing directives for the particular character defined by said first data signal; second memory means for storing encoded initial values for each character-shape dependent stroke attribute, said initial values being independent of the character type; logic means modifying selected encoded initial values in said second memory means based upon the character rotation; decoding means for receiving said encoded stroke-drawing directives corresponding to the character type specified by said first data signal and for receiving said encoded initial values, said decoding means decoding said encoded stroke-drawing directives and said encoded initial values and sequentially applying the decoded drawing directives to the decoded initial values thereby generating a series of stroke signals representing a series of interconnected stroke-vectors; scaling means for receiving said stroke signals and said first data signal, said scaling means setting the length of each stroke-vector so that the character image is scaled to the character field dimensions defined by said first data signal; and conversion means converting said stroke signals into a series of signals designating the start/stop position of each interconnected stroke-vector, said series of signals defining a character image for the character type defined by said first data signal.

Claim 11

A character generator as in claim 8 further comprising: pel-generator means receiving said series of signals, said means generating signals PELX-LENGTH and PELY-LENGTH corresponding to the X,Y dimensions of a logical pel, said pel-generator means also generating an output signal corresponding to the pixel location on said display screen of said series of signals with the logical-pel superimposed thereon.

Claim 12

A character generator as in claim 8 wherein said pel-generator means develops the signal PELX-LENGTH so that x-dimension of the logical-pel is equal to the x-dimension of each horizontal stroke-vector and also develops the signal PELY-LENGTH so that the y-dimension of the logical pel is equal to the y-dimension of each vertical stroke-vector.

Claim 13

A character generator as in claim 10 further comprising frame buffer means to store said output signal from said pel-generator means to enable the display system to repeatedly scan said frame buffer means to display the desired character.

Claim 14

A character generator as in claim 10 further comprising means for projecting onto said display screen at said character drawing point said character mask with the logical-pel superimposed thereon and thereby generating the desired character display.

Claim 15

A character generator as in claim 10 wherein said scaling means adjusts the length of each stroke-vector such that the horizontal stroke-vector span and the vertical stroke-vector span are equal to the respective character field dimensions specified by said first data signal.

Claim 16

A character generator as in claim 13 wherein said first memory means further comprises: means for decoding said first data signal to generate a character code output signal defining the character type; means for addressing a memory location in said first memory means using said character code output signal as a memory address; and means for reading out of said first memory means a plurality of encoded binary valued stroke-drawing directives.

Claim 17

A character generator as in claim 14 wherein said means for receiving a first data signal further comprises a data latch.

Claim 18

A character generator as in claim 15 wherein said decoding means further comprises a microprocessor unit.

Claim 19

In a random scan graphic display system, a stroke-vector character generator for generating a series of signals for use in displaying characters on a display screen, said generator comprising: means for receiving a first data signal defining the character type to be displayed, the character field dimensions, the character drawing point, and the character rotation; first memory means for storing a plurality of encoded binary valued stroke-drawing directives for the particular character defined by said first data signal; second memory means for storing encoded initial values for each character-shape dependent stroke attribute, said initial values being independent of the character type; logic means modifying selected encoded initial values in said second memory means based upon the character rotation; decoding means for receiving said encoded stroke-drawing directives corresponding to the character type specified by said first data signal and for receiving said encoded initial values, said decoding means decoding said encoded stroke-drawing directives and said encoded initial values and sequentially applying the decoded drawing directives to the decoded initial values thereby generating a series of stroke signals representing a series of interconnected uniformly long stroke-vectors; scaling means for receiving said stroke signals and said first data signal, said scaling means setting the length of each stroke-vector so that the character image is scaled to the character field dimensions defined by said first data signal; conversion means converting said stroke signals into a series of signals designating the start/stop position of each interconnected stroke-vector, said series of signals defining a character mask for the character type defined by said first data signal; and pel-generator means receiving said series of signals, said means generating signals PELX-LENGTH and PELY-LENGTH corresponding to the X,Y dimensions of a logical pel so that the x-dimension of the logical-pel is equal to the x-dimension of each horizontal stroke-vector and so that the y-dimension of the logical pel is equal to the y-dimension of each vertical stroke-vector, said pel-generator means also generating an output signal corresponding to the pixel location on said display screen of said series of signals with the logical-pel superimposed thereon.

Claim 20

In a random scan graphic display system, a stroke-vector character generator for generating a series of signals for use in displaying characters on a display screen, said generator comprising: means for receiving a first data signal defining the character type to be displayed, the character field dimensions, the character drawing point, and the character rotation; first memory means for storing a plurality of encoded binary valued stroke-drawing directives for the particular character defined by said first data signal; second memory means for storing encoded initial values for each character-shape dependent stroke attribute, said initial values being independent of the character type; logic means modifying selected encoded initial values in said second memory means based upon the character rotation; decoding means for receiving said encoded stroke-drawing directives corresponding to the character type specified by said first data signal and for receiving said encoded initial values, said decoding means decoding said encoded stroke-drawing directives and said encoded initial values and sequentially applying the decoded drawing directives to the decoded initial values thereby generating a series of stroke signals representing a series of interconnected uniformly long stroke-vectors; scaling means for receiving said stroke signals and said first data signal, said scaling means setting the length of each stroke-vector so that the character image is scaled to the character field dimensions defined by said first data signal; conversion means converting said stroke signals into a series of signals designating the start/stop position of each interconnected stroke-vector, said series of signals defining a character mask for the character type defined by said first data signal; and pel-generator means receiving said series of signals, said means generating signals PELX-LENGTH and PELY-LENGTH corresponding to the X,Y dimensions of a logical pel so that the x-dimension of the logical-pel is equal to the x-dimension of each horizontal stroke-vector and so that the y-dimension of the logical pel is equal to the y-dimension of each vertical stroke-vector, said pel-generator means also generating an output signal corresponding to the pixel location on said display screen of said series of signals with the logical-pel superimposed thereon.