US5416897A
Expired / Lapsed
US
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Video graphics controller with selectable pattern features for line draws
Assignee: Hewlett Packard Development Co LP
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Filing: 1993-09-07
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Granted: 1995-05-16
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Expires: 2013-09-07
Abstract
Abstract Circuitry for drawing lines includes a video memory for storing pixel data and circuitry 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 current pattern unit. Writing circuitry writes to the video memory at a generated address responsive to a current pattern unit. A third 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 memory to a predetermined pattern unit.
Inventors
- 👤 Thomas M. Albers
- 👤 John V. Eberst
- 👤 Darwin Fontenot
- 👤 Richard L. Pyra
- 👤 Mark W. Welker
- 👤 Paul B. Wood
- 👤 Jack E. Bresenham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:23
CPC Classifications
G; G06; G06T; G06T11/00; G06T11/20; G06T11/23
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
182 words
Circuitry for drawing lines, comprising: a video memory for storing pixel data; circuitry for generating a sequence of addresses in said video memory responsive to programmable line parameters, said sequence of addresses defining a line of pixels beginning with a first pixel and terminating with a last pixel; a first memory for storing a sequence of pattern units defining pixel characteristics to be applied to said line of pixels; a second memory for storing a value indicating a current pattern unit in said sequence of pattern units; circuitry for writing to said video memory at a generated address responsive to said current pattern unit; a third memory for storing a control value; and circuitry for updating the second memory to indicate a next pattern unit, said updating circuitry selectively updating, responsive to said control value, said second memory to the next pattern unit or resetting said second memory to a predetermined pattern unit after writing the last pixel of the line to said video memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 2
Dependent Claim
182 words
Circuitry for drawing lines, comprising: a video memory for storing pixel data; circuitry for generating a sequence of addresses in said video memory responsive to programmable line parameters, said sequence of addresses defining a line of pixels beginning with a first pixel and terminating with a last pixel; a first memory for storing a sequence of pattern units defining pixel characteristics to be applied to said line of pixels; a second memory for storing a value indicating a current pattern unit in said sequence of pattern units; circuitry for writing to said video memory at a generated address responsive to said current pattern unit; a third memory for storing a control value; and circuitry for updating the second memory to indicate a next pattern unit, said updating circuitry selectively updating, responsive to said control value, said second memory to the next pattern unit or resetting said second memory to a predetermined pattern unit after writing the last pixel of the line to said video memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 3
Dependent Claim
15 words
The circuitry for drawing lines of claim 1 wherein each pattern unit comprises a bit.
Claim 4
Dependent Claim
61 words
The circuitry for drawing lines of claim 2 wherein said first memory comprises a plurality of bits and further comprising a foreground color memory for storing a value indicative of a foreground color and a background color memory for storing a value indicative of a background color, each bit of said first memory being indicative of one of the color memories.
Claim 5
Dependent Claim
24 words
The circuitry for drawing lines of claim 1 and further comprising first endpoint memory for storing coordinates of a first endpoint of a line.
Claim 6
Dependent Claim
25 words
The circuitry for drawing lines of claim 4 and further comprising circuitry for transferring the coordinates of a last pixel to said first endpoint memory.
Claim 7
Dependent Claim
37 words
The circuitry for drawing lines of claim 1 and further comprising a fourth memory for storing a second control value, said writing circuitry selectively writing the last pixel of a line responsive to said second control value.
Claim 8
Dependent Claim
23 words
The circuitry for drawing lines of claim 6 wherein said updating circuitry selectively updates the second memory responsive to said second control value.
Claim 9
Dependent Claim
47 words
The circuitry for drawing lines of claim 1 and further comprising: a fourth memory for storing a pattern end pointer indicating the last pattern unit in a desired pattern; and circuitry to update the second memory to a predetermined pattern unit responsive to said pattern end pointer.
Claim 10
Independent Claim
152 words
A method of drawing lines with a graphics processor comprising the steps of: storing a sequence of pattern units in a first memory; generating a series of pixel addresses defining a line having a first pixel address representing a first endpoint and a second pixel address representing a second endpoint; for each generated pixel address, storing a value in a second memory, said value indicative of the location of a current pattern unit in the first memory; for each generated pixel address, writing pixel data based on the current pattern unit to a video memory; and after writing pixel data to the last pixel address, selectively updating the value stored in the second memory to a value indicating a next sequential location in said first memory or to a predetermined location in said first memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 11
Independent Claim
152 words
A method of drawing lines with a graphics processor comprising the steps of: storing a sequence of pattern units in a first memory; generating a series of pixel addresses defining a line having a first pixel address representing a first endpoint and a second pixel address representing a second endpoint; for each generated pixel address, storing a value in a second memory, said value indicative of the location of a current pattern unit in the first memory; for each generated pixel address, writing pixel data based on the current pattern unit to a video memory; and after writing pixel data to the last pixel address, selectively updating the value stored in the second memory to a value indicating a next sequential location in said first memory or to a predetermined location in said first memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 12
Dependent Claim
25 words
The method of claim 9 wherein said step of storing a sequence of pattern units comprises the step of storing a sequence of pattern bits.
Claim 13
Dependent Claim
40 words
The method of claim 10 and further comprising the steps of storing foreground and background colors, wherein said writing step comprises the step of writing a foreground or background color to said video memory responsive to said current pattern unit.
Claim 14
Dependent Claim
26 words
The method of claim 9 and further comprising the step of storing the coordinates of a first endpoint of a line in a first endpoint memory.
Claim 15
Dependent Claim
26 words
The method of claim 12 and further comprising the step of transferring the coordinates of a last pixel of a line to said first endpoint memory.
Claim 16
Dependent Claim
51 words
The method of claim 9 and further comprising the step of storing a second control value in a fourth memory, wherein said writing step comprises the step of writing to said video memory at a generated address corresponding to the last pixel of a line responsive to said second control value.
Claim 17
Dependent Claim
41 words
The method of claim 9 and further comprising the steps of: storing a pattern end pointer indicating the last pattern unit in a desired pattern; and updating the second memory to a predetermined pattern unit responsive to said pattern end pointer.
Claim 18
Dependent Claim
200 words
A computer system comprising: a processor; a display; and a graphics processor coupled to said processor and said display, said graphics processor comprising: a video memory for storing pixel data; circuitry for generating a sequence of addresses in said video memory responsive to programmable line parameters, said sequence of addresses defining a line of pixels beginning with a first pixel and terminating in a last pixel; a first memory for storing a sequence of pattern units defining pixel characteristics to be applied to said line of pixels; a second memory for storing a value indicating a current pattern unit in said sequence of pattern units; circuitry for writing to said video memory at a generated address responsive to said current pattern unit; a third memory for storing a control value; and circuitry for updating the second memory to indicate a next pattern unit, said updating circuitry selectively updating, responsive to said control value, said second memory to the next pattern unit or resetting said second memory to a predetermined pattern unit after writing the last pixel of the line to said video memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 19
Dependent Claim
200 words
A computer system comprising: a processor; a display; and a graphics processor coupled to said processor and said display, said graphics processor comprising: a video memory for storing pixel data; circuitry for generating a sequence of addresses in said video memory responsive to programmable line parameters, said sequence of addresses defining a line of pixels beginning with a first pixel and terminating in a last pixel; a first memory for storing a sequence of pattern units defining pixel characteristics to be applied to said line of pixels; a second memory for storing a value indicating a current pattern unit in said sequence of pattern units; circuitry for writing to said video memory at a generated address responsive to said current pattern unit; a third memory for storing a control value; and circuitry for updating the second memory to indicate a next pattern unit, said updating circuitry selectively updating, responsive to said control value, said second memory to the next pattern unit or resetting said second memory to a predetermined pattern unit after writing the last pixel of the line to said video memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 20
Dependent Claim
13 words
The computer system of claim 16 wherein each pattern unit comprises a bit.
Claim 21
Dependent Claim
59 words
The computer system of claim 17 wherein said first memory comprises a plurality of bits and further comprising a foreground color memory for storing a value indicative of a foreground color and a background color memory for storing a value indicative of a background color, each bit of said first memory being indicative of one of the color memories.
Claim 22
Dependent Claim
22 words
The computer system of claim 16 and further comprising first endpoint memory for storing coordinates of a first endpoint of a line.
Claim 23
Dependent Claim
23 words
The computer system of claim 19 and further comprising circuitry for transferring the coordinates of a last pixel to said first endpoint memory.
Claim 24
Dependent Claim
35 words
The computer system of claim 16 and further comprising a fourth memory for storing a second control value, said writing circuitry selectively writing the last pixel of a line responsive to said second control value.
Claim 25
Dependent Claim
21 words
The computer system of claim 21 wherein said updating circuitry selectively updates the second memory responsive to said second control value.
Claim 26
Dependent Claim
45 words
The computer system of claim 16 and further comprising: a fourth memory for storing a pattern end pointer indicating the last pattern unit in a desired pattern; and circuitry to update the second memory to a predetermined pattern unit responsive to said pattern end pointer.
Claim 27
Dependent Claim
233 words
Circuitry for drawing lines, comprising: a video memory for storing pixel data; circuitry for generating a sequence of addresses in said video memory responsive to programmable line parameters, said sequence of addresses defining a line of pixels beginning with a first pixel and terminating with a last pixel; a first memory having a plurality of bits, the bits storing a sequence of pattern units defining pixel characteristics to be applied to said line of pixels; a second memory for storing a value indicating a current bit of said first memory; a foreground color memory for storing a value indicative of a foreground color and a background color memory for storing a value indicative of a background color, wherein the value of each bit of said first memory indicates one of the color memories; circuitry for writing to said video memory at a generated address based on the color memory indicated by the current bit; a third memory for storing a control value; and circuitry for updating the second memory to indicate a next bit in said first memory, said updating circuitry selectively updating, responsive to said control value, said second memory to the next bit or resetting said second memory to a predetermined bit after writing a last pixel of the line to said video memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 28
Dependent Claim
233 words
Circuitry for drawing lines, comprising: a video memory for storing pixel data; circuitry for generating a sequence of addresses in said video memory responsive to programmable line parameters, said sequence of addresses defining a line of pixels beginning with a first pixel and terminating with a last pixel; a first memory having a plurality of bits, the bits storing a sequence of pattern units defining pixel characteristics to be applied to said line of pixels; a second memory for storing a value indicating a current bit of said first memory; a foreground color memory for storing a value indicative of a foreground color and a background color memory for storing a value indicative of a background color, wherein the value of each bit of said first memory indicates one of the color memories; circuitry for writing to said video memory at a generated address based on the color memory indicated by the current bit; a third memory for storing a control value; and circuitry for updating the second memory to indicate a next bit in said first memory, said updating circuitry selectively updating, responsive to said control value, said second memory to the next bit or resetting said second memory to a predetermined bit after writing a last pixel of the line to said video memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 29
Dependent Claim
219 words
Circuitry for drawing lines, comprising: a video memory for storing pixel data; circuitry for generating a sequence of addresses in said video memory responsive to programmable line parameters, said sequence of addresses defining a line of pixels beginning with a first pixel and terminating with a last pixel; a first memory for storing a sequence of pattern units defining pixel characteristics to be applied to said line of pixels; a second memory for storing a value indicating a current pattern unit in said sequence of pattern units; circuitry for writing to said video memory at a generated address responsive to said current pattern unit; a third memory for storing a control value; and a fourth memory for storing a pattern end pointer indicating the last pattern unit in a desired pattern; circuitry to update the second memory to a first predetermined pattern unit responsive to said pattern end pointer; circuitry for updating the second memory to indicate a next pattern unit, said updating circuitry selectively updating, responsive to said control value, said second memory to the next pattern unit or resetting said second memory to a second predetermined pattern unit after writing the last pixel of the line to said video memory such that a pattern may be selectably continued or reset at the start of a next line.
Claim 30
Dependent Claim
219 words
Circuitry for drawing lines, comprising: a video memory for storing pixel data; circuitry for generating a sequence of addresses in said video memory responsive to programmable line parameters, said sequence of addresses defining a line of pixels beginning with a first pixel and terminating with a last pixel; a first memory for storing a sequence of pattern units defining pixel characteristics to be applied to said line of pixels; a second memory for storing a value indicating a current pattern unit in said sequence of pattern units; circuitry for writing to said video memory at a generated address responsive to said current pattern unit; a third memory for storing a control value; and a fourth memory for storing a pattern end pointer indicating the last pattern unit in a desired pattern; circuitry to update the second memory to a first predetermined pattern unit responsive to said pattern end pointer; circuitry for updating the second memory to indicate a next pattern unit, said updating circuitry selectively updating, responsive to said control value, said second memory to the next pattern unit or resetting said second memory to a second predetermined pattern unit after writing the last pixel of the line to said video memory such that a pattern may be selectably continued or reset at the start of a next line.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-05-15 | 1998-11-14 | 1999-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-15 | 2002-11-14 | 2003-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-15 | 2006-11-14 | 2007-05-16 | $7700.00 | Window Closed / Lapsed |