US 4,533,910 A · Graphics display system with viewports of arbitrary location and content

Abstract

In this computer graphics display system, individual viewports of arbitary arrangement, number and content are produced on a video screen. The graphics content, display parameters and interviewport spacing all are specified by a set of control word sequences stored in a control table. Each sequence is associated with one scan line segment of an individual viewport, and consists of one or more control words that specify (a) the graphics image memory location of the pixel data to be included in that viewport segment, and (b) display parameters which specify how that pixel data is to be processed before supply to the video screen. Control word display parameters and the associated graphics image (pixel) data are alternately obtained from a control/pixel memory and supplied to a first-in-first-out (FIFO) memory. At the outbound side of the FIFO memory, a controller enters the display parameters in appropriate registers. Pixel data then is serialized and processed in accordance with these display parameters, which may include color, zoom replication, and background grid insertion. After supplying the processed graphics data to the video screen, the controller supplies background control signals so as to produce an interviewport region on the video screen in accordance with the interviewport spacing specified by the control word sequences. Panning in any viewport is accomplished by altering the control word sequences associated with successive video frames so as to specify different sets of pixel data which, when reproduced in successive frames, give the illusion of image movement.

Claims22

Dependent claims

A graphics display system of the type in which pixel data stored in a pixel memory is accessed and displayed on a video screen, said system facilitating the arbitary screen location and pixel content of one or more viewports, comprising:

control memory means for storing a control table comprising a set of control word sequences each consisting of one or more control words, each sequence specifying the portion of said stored pixel data which is to be displayed in a corresponding segment of a viewport associated with that sequence, and specifying other display parameters for said associated viewport,
first controller means for accessing from said pixel memory the pixel data portion specified by each control word sequence, and
second controller means for displaying said accessed pixel data portion in accordance with said display parameters specified by the associated control word sequence,
said first and second controller means operating repetitively in accordance with consecutive control word sequences to produce a complete screen display in which the viewport arrangement and content are defined by said sequences.

1 more element

A graphics display system facilitating the display on a video screen of plural different viewport images each having different display parameters and being arbitrarily situated on said screen, comprising:

a pixel memory storing graphics image pixel data,
a stored control table containing a set of control word sequences each consisting of at least one control word, each control word sequence specifying the parameters of a segment of a single viewport to be produced along a single video scan line, said parameters including the pixel memory storage address of pixel data for that viewport segment and the interviewport spacing between that viewport segment and the next viewport segment to be produced on the same or the next video scan line, and
means for utilizing said control word sequence to direct the display of said pixel data from said pixel memory onto said video screen in accordance with the parameters and interviewport spacings specified by said control word sequences to produce a video display defined by said control table.

A video graphics display system comprising:

a video screen,
a control/pixel memory means for storing graphics display pixel data and control words each specifying display parameters for a portion of the video screen,
a first-in-first-out (FIFO) memory,
an inbound FIFO controller means for alternately supplying to said FIFO memory display parameters of one or more control words and graphics display data identified by the supplied control words, said alternate supplying occurring repetitively and sequentially for a plurality of control words defining a complete frame of a video display, and
an outbound FIFO controller means for alternately obtaining from said FIFO memory said display parameters and the identified graphics display data, and for converting and supplying to the video screen the obtained graphics display data in accordance with the obtained display parameters.

2 more elements

A graphics display system facilitating the display on a video screen of a viewport image, comprising:

a pixel memory storing graphics image pixel data in multibit word format, the pixel data defining a first portion of the viewport image being stored in a first region of said pixel memory and the pixel data defining a second portion of the same viewport being stored in a different region of the pixel memory,
a stored control table containing a set of control word sequences each consisting of at least two control words, each control word sequence specifying the parameters of a segment of said viewport image, the parameters of one control word including the pixel memory start address of pixel data for a first portion of said viewport image segment, and including an offset address within the first multibit word containing pixel data for said first portion in the event that the pixel data for said first portion does not begin on a word boundary of a multibit word in said pixel memory, the parameters of a second control word including the pixel memory start address of pixel data for the second portion of said viewport image segment, and
display production means for utilizing said control word sequence to access said pixel data from portions of said pixel memory identified by said start addresses and to direct the display of said accessed pixel data onto said video screen in accordance with said parameters to produce said viewport image.

Dependencies are inferred from the claim text.

Graphics display system with viewports of arbitrary location and content

Life of this patent

Graphics display system with viewports of arbitrary location and content

Life of this patent

Abstract

Claims22