US5883634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method for clipping pixels drawn in one of a plurality of windows in a computer graphics system
Assignee: International Business Machines Corp
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Filing: 1996-07-25
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Granted: 1999-03-16
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Expires: 2016-07-25
Abstract
Abstract A system and method for performing efficient clipping to visible windows. A window clip buffer is established for each window being written directly to the front frame buffer. The window clip buffer is initialized as having the same dimensions as the window itself and each pixel position is initially set to False (not visible.) The visible regions are determined and the buffer updated to True (visible) for those visible regions. As each pixel is being drawn the window clip buffer is tested. The pixel is drawn to the frame buffer only where the window clip buffer pixel is true (visible.) Changes to window positions on the screen causes the visible regions to be updated.
Inventors
- 👤 Chandrasekhar Narayanaswami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:18
CPC Classifications
G; G09; G09G; G09G5/00; G09G5/14; G06; G06T; G06T11/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
233 words
A computer system for processing and displaying images, comprising: one or more processors; at least one storage system, each comprising a random access memory, disk controller, and permanent storage unit, connected to said processor for storing programs and data; a display device for displaying information in a plurality of windows, said information in each said window being associated with one or more applications; and a graphics processor for processing data representing graphics images, said graphics processor operatively connected to said one or more processors and said at least one storage system, further comprising: means for allocating a window clipping buffer in said random access memory in one of said at least one storage subsystem; means for initializing said window clipping buffer to a first value; means for determining regions of one of said plurality of windows that are obscured by others of said plurality of windows on said display device; means for writing a second value to said window clipping buffer at locations in said window clipping buffer corresponding to one or more portions of said window that are visible; means for testing each location in said window clipping buffer to determine if said location represents a visible pixel in a window to be displayed on said display device; and means for writing said graphics image data associated with said window to a frame directly, if a pixel to be written is visible.
Claim 2
Dependent Claim
233 words
A computer system for processing and displaying images, comprising: one or more processors; at least one storage system, each comprising a random access memory, disk controller, and permanent storage unit, connected to said processor for storing programs and data; a display device for displaying information in a plurality of windows, said information in each said window being associated with one or more applications; and a graphics processor for processing data representing graphics images, said graphics processor operatively connected to said one or more processors and said at least one storage system, further comprising: means for allocating a window clipping buffer in said random access memory in one of said at least one storage subsystem; means for initializing said window clipping buffer to a first value; means for determining regions of one of said plurality of windows that are obscured by others of said plurality of windows on said display device; means for writing a second value to said window clipping buffer at locations in said window clipping buffer corresponding to one or more portions of said window that are visible; means for testing each location in said window clipping buffer to determine if said location represents a visible pixel in a window to be displayed on said display device; and means for writing said graphics image data associated with said window to a frame directly, if a pixel to be written is visible.
Claim 3
Dependent Claim
32 words
The computer system, according to claim 1, wherein said means for determining visible regions and said means for writing a second value operate whenever a window is created on said display device.
Claim 4
Dependent Claim
32 words
The computer system, according to claim 1, wherein said means for determining visible regions and said means for writing a second value operate whenever a window on said display device is deleted.
Claim 5
Dependent Claim
32 words
The computer system, according to claim 1, wherein said means for determining visible regions and said means for writing a second value operate whenever a window on said display device is modified.
Claim 6
Independent Claim
181 words
A method for processing data being drawn as graphics images into one of a plurality of windows to be displayed on a display device of a computer system and at least one storage system, each said storage system including a random access memory, disk controller, and permanent storage unit, comprising the steps of: allocating a window clipping buffer in said random access memory in one of said at least one storage subsystem; initializing said window clipping buffer to a first value; determining regions of one of said plurality of windows that are obscured by others of said plurality of windows on said display device; writing a second value to said window clipping buffer at locations in said window clipping buffer corresponding to one or more portions of said window that are visible; testing each location in said window clipping buffer to determine if said location represents a visible pixel in a window to be displayed on said display device; and writing said graphics image data associated with said window to a frame directly, if a pixel to be written is visible.
Claim 7
Independent Claim
181 words
A method for processing data being drawn as graphics images into one of a plurality of windows to be displayed on a display device of a computer system and at least one storage system, each said storage system including a random access memory, disk controller, and permanent storage unit, comprising the steps of: allocating a window clipping buffer in said random access memory in one of said at least one storage subsystem; initializing said window clipping buffer to a first value; determining regions of one of said plurality of windows that are obscured by others of said plurality of windows on said display device; writing a second value to said window clipping buffer at locations in said window clipping buffer corresponding to one or more portions of said window that are visible; testing each location in said window clipping buffer to determine if said location represents a visible pixel in a window to be displayed on said display device; and writing said graphics image data associated with said window to a frame directly, if a pixel to be written is visible.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-15 | 2002-09-14 | 2003-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-15 | 2006-09-14 | 2007-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-15 | 2010-09-14 | 2011-03-16 | $7700.00 | Window Closed / Lapsed |