Computer graphics processing and selective visual display system – Computer graphic processing system – Plural graphics processors
Reexamination Certificate
1998-08-21
2001-06-19
Chauhan, Ulka J. (Department: 2671)
Computer graphics processing and selective visual display system
Computer graphic processing system
Plural graphics processors
C345S506000, C709S209000
Reexamination Certificate
active
06249294
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to computer graphics display systems. More particularly, the invention relates to a solution for providing 3D graphics in a single logical screen display supported by multiple remote computer systems.
BACKGROUND
Computer graphics displays that have very large sizes and high resolutions are useful in a variety of applications. For example, such displays can be used to create immersive environments in which viewers are surrounded by the display. Such displays are also useful when large amounts of data must be viewable on one large screen, such as in stock market applications, large process control applications and the like. Frequently, in order to provide such a large display with adequately high resolution, a composite screen must be constructed using numerous separate physical display devices such as CRT-type monitors. If the composite screen is to be used interactively, then suitable control mechanisms must also be for a Large, Physical Workspace” (hereinafter “Walls, et al.”), which patent application is hereby incorporated entirely by reference.
By way of background, the X Window System is a standard for implementing window-based user interfaces in a networked computer system. For a more detailed discussion of the X Window System and the X Protocol that defines it, see Adrian Nye,
X Protocol Reference Manual Volume Zero
(O'Reilly & Associates 1990).
FIG. 1
illustrates a conventional X Window System configuration that does not implement single logical screen functionality. Host computer system
100
is coupled to host computer system
102
via connections to local area network (“LAN”)
104
. Host computer system
102
drives display hardware
106
via bus
108
and is capable of receiving input from devices such as a keyboard
109
, a mouse
111
or other devices such as a button box
113
. X client software
110
runs on host
100
, while X server software
112
runs on host
102
. Although configurations of client
110
may vary, a typical client would comprise an application
114
that communicates with server
112
by means of calls to low-level library Xlib
116
. Optionally, Xlib
116
may be augmented by a higher-level library such as XToolkit
118
. The purpose of X server
112
is to implement a user interface on display hardware
106
responsive to commands received from X client
110
and input devices
109
,
111
and
113
. A conventional X server
112
includes three basic components: a device independent X (“DIX”) layer
120
, an operating system (“OS”) layer
122
, and a device dependent X (“DDX”) layer
124
. DIX layer
120
contains the parts of the server software that are portable from one hardware/OS implementation to another. OS layer
122
implements server functions that vary with specific operating systems. DDX layer
124
implements server functions that depend on the capabilities of particular graphics hardware and input devices. For a more detailed discussion of conventional X server
112
, see, Elias Israel and Erik Fortune, The X Window System Server (Digital Press 1992) (hereinafter “Israel and Fortune”).
FIG. 2
illustrates an X Window System configuration that implements 2D single logical screen functionality according to the teaching of Walls, et al. In the configuration of
FIG. 2
, augmented X server software
200
runs on host computer
220
. X server
200
controls multiple display hardware devices
202
,
204
,
208
and
208
via buses
203
,
205
,
207
and
209
. This capability is accomplished by the addition of a single-logical-screen (“SLS”) layer
210
to X server
200
, as well as a separate DDX layer
212
,
214
,
216
and
218
for each of the display hardware devices. An advantage of the configuration of
FIG. 2
is that single logical screen functionality is provided in a way that is transparent to X Client
110
. In other words, the single logical screen functionality provided by X Server
200
enables X Client
110
to function as though it were communicating with one large, high-resolution device. The overhead required to provide the high-resolution single logical screen functionality using several smaller-resolution devices is subsumed entirely within X server
200
.
The configuration of
FIG. 2
does have limitations, however. One of the challenges associated with implementing a very large single logical screen display is that many physical display devices are required to implement the composite screen. Moreover, each of the physical display devices in the composite screen is usually driven by a separate graphics hardware subsystem. Typically, each such graphics hardware subsystem resides on a graphics circuit card (or cards), which must be installed in a bus socket (or sockets) on the backplane of a host computer system. Unfortunately, there is a physical limit to the number of graphics circuit cards that may be installed into the bus sockets that are provided on a single backplane. While special-purpose backplanes have been built that are capable of receiving as many as nine graphics circuit cards at once, such special-purpose implementations are expensive. The backplanes in more conventional computer systems are only able to receive about four graphics circuit cards for 2D hardware, and fewer than four cards for 3D hardware. (3D graphics circuit cards can require three or more bus slots per card.)
One way of addressing the need for having many graphics circuit cards when attempting to implement a very large single logical screen display would be to use numerous computer systems to support the composite screen. In this manner, numerous backplanes would be provided for receiving the graphics circuit cards (one backplane per computer system). Moreover, each of the computer systems used to support the larger logical screen could be configured like computer system
220
shown in FIG.
2
. Unfortunately, the configuration shown in
FIG. 2
is only transparent to X client
110
when X server
200
manages the entire logical screen. Therefore, if multiple computer systems
220
were used in order to create a larger logical screen, with each of the computer systems
220
running a separate X server
200
, then X client
110
would have to assume a degree of the overhead required to implement the SLS functionality for the larger composite screen. Moreover, only 2D single logical screen functionality is supported by the configuration of FIG.
2
.
It is therefore an object of the present invention to provide 3D SLS functionality for very large composite screens in a manner that is transparent to the application software in the X client.
It is a further object of the invention to provide such 3D SLS functionality in a manner that enables multiple backplanes to be used for implementing very large composite screens.
SUMMARY OF THE INVENTION
The invention includes a number of unique aspects, each of which contributes to the achievement of the above-stated objects in a high-performance manner.
In one aspect, the invention includes a single logical screen computer display using multiple remote computer systems operable to perform hardware accelerated 3D graphics operations. The display system includes a client process, a first slave host computer coupled to first display hardware, a second slave host computer coupled to second display hardware, and a network broadcast path between the client process and the first and second slave host computers. The client process is operable to broadcast OGL command buffers to the first and second slave host computers using the network broadcast path. The first and second slave host computers are operable to execute OGL commands in the OGL command buffers and to render the results on the first and second display hardware, respectively.
In a further aspect, first and second X server processes run on the first and second slave hosts, and first and second OGL daemon processes also run on the first and second slave hosts. The first and second OGL daemons are operable to execute OGL commands in the OGL command buffers and to render the results on t
Hamilton Michael T.
Hoffman Don B.
Lefebvre Kevin
Chauhan Ulka J.
Hart Kevin M.
Hewlett--Packard Company
LandOfFree
3D graphics in a single logical sreen display using multiple... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with 3D graphics in a single logical sreen display using multiple..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and 3D graphics in a single logical sreen display using multiple... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2446781