[Federal Register Volume 60, Number 18 (Friday, January 27, 1995)]
[Notices]
[Pages 5362-5368]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-2103]
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DEPARTMENT OF COMMERCE
National Institute of Standards and Technology
[Docket No. 940541-4339]
RIN 0693-AB30
Approval of Federal Information Processing Standards Publication
153-1, Programmer's Hierarchical Interactive Graphics System (PHIGS)
AGENCY: National Institute of Standards and Technology (NIST),
Commerce.
ACTION: The purpose of this notice is to announce that the Secretary of
Commerce has approved a revised standard, which will be published as
FIPS Publication 153-1, Programmer's Hierarchical Interactive Graphics
System (PHIGS).
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SUMMARY: On June 17, 1994 (59 FR 31209-31214), notice was published in
the Federal Register that a revision to Federal Information Processing
Standard 153, Programmer's Hierarchical Interactive Graphics System
(PHIGS) was being proposed for Federal use.
The written comments submitted by interested parties and other
material available to the Department relevant to the revised standard
was reviewed by NIST. On the basis of this review, NIST recommended
that the Secretary approve the revised standard as a Federal
Information Processing Standards Publication, and prepared a detailed
justification document for the Secretary's review in support of that
recommendation.
The detailed justification document which was presented to the
Secretary is part of the public record and is available for inspection
and copying in the Department's Central Reference and Records
Inspection Facility, Room 6020, Herbert C. Hoover Building, 14th Street
between Pennsylvania and Constitution Avenues, NW, Washington, DC
20230.
This FIPS contains two sections: (1) An announcement section, which
provides information concerning the applicability, implementation, and
maintenance of the standard; and (2) a specifications section which
deals with the technical requirements of the standard. Only the
announcement section of the standard is provided in this notice.
EFFECTIVE DATE: This revised standard becomes effective August 1, 1995.
ADDRESSES: Interested parties may purchase copies of this revised
standard, including the technical specifications section, from the
National Technical Information Service (NTIS). Specific ordering
information from NTIS for this standard is set out in the Where to
Obtain Copies Section of the announcement section of the standard.
FOR FURTHER INFORMATION CONTACT:
Mr. Kevin G. Brady, telephone (301) 975-3644, National Institute of
Standards and Technology, Gaithersburg, MD 20899.
Dated: January 18, 1995.
Samuel Kramer,
Associate Director.
Federal Information Processing Standards Publication 153-1
(date)
Announcing the Standard for Programmer's Hierarchical Interactive
Graphics System (PHIGS)
Federal Information Processing Standards Publications (FIPS PUBS)
are issued by the National Institute of Standards and Technology after
approval by the Secretary of Commerce pursuant to Section 111(d) of the
Federal Property and Administrative Services Act of 1949 as amended by
the Computer Security Act of 1987, Public Law 100-235.
1. Name of Standard. Programmer's Hierarchical Interactive Graphics
System (PHIGS) (FIPS PUB 153-1).
2. Category of Standard. Software Standard, Graphics.
3. Explanation. This publication is a revision of FIPS PUB 153 and
supersedes that document in its entirety. This revision provides a
substantial, upward-compatible enhancement of the basic PHIGS
functionality known as Plus Lumiere and Surfaces, PHIGS PLUS (ANSI/ISO
9592.1a,2a,3a,4:1992). PHIGS PLUS adds facilities for the specification
of curved lines, curved and faceted surfaces, lighting and shading, and
adds a mechanism for color specification to allow non-indexed color
specification. Amendments to each part of the PHIGS specification
detail revisions required by PHIGS PLUS. Also, each language binding of
PHIGS has been amended as a result of PHIGS PLUS. The specifications
and amendments that comprise the complete PHIGS standard as a result of
this revision are detailed in the Specification section of this
document.
In addition this revision adds a requirement for validation of
PHIGS implementations using either FORTRAN or C bindings. However,
[[Page 5363]] validation is currently limited to basic PHIGS
functionality, and therefore does not include the new functionality of
PHIGS PLUS added by this revision.
FIPS 153-1 adopts the American National Standard Programmer's
Hierarchical Interactive Graphics System, ANSI/ISO 9592.1-3:1989, and
ANSI/ISO 9592.1a,2a,3a,4:1992, and 9593.1:1990, 9593.3:1990,
9593.4:1991, as a Federal Information Processing Standard (FIPS). This
standard specifies the control and data interchange between an
application program and its graphic support system. It provides a set
of functions and programming language bindings for the definition,
display and modification of geometrically related objects, graphical
data, and the relationships between the graphical data. The purpose of
the standard is to promote portability of graphics application programs
between different installations. The standard is for use by
implementors as the reference authority in developing graphics software
systems; and by other computer professionals who need to know the
precise syntactic and semantic rules of the standard.
4. Approving Authority. Secretary of Commerce.
5. Maintenance Agency. U.S. Department of Commerce, National
Institute of Standards and Technology (NIST), Computer Systems
Laboratory (CSL).
6. Cross Index.
a. ANSI/ISO 9592.1:1989, Information Processing Systems--Computer
Graphics--Programmer's Hierarchical Interactive Graphics System
(PHIGS), Part 1, Functional Description.
b. ANSI/ISO 9592.1a:1992, Amendment 1, Information Processing
Systems--Computer Graphics--Programmer's Hierarchical Interactive
Graphics System (PHIGS), Part 1, Functional Description.
c. ANSI/ISO 9592.2:1989, Information Processing Systems--Computer
Graphics--Programmer's Hierarchical Interactive Graphics System
(PHIGS), Part 2, Archive File Format.
d. ANSI/ISO 9592.2a:1992, Amendment 1, Information Processing
Systems--Computer Graphics--Programmer's Hierarchical Interactive
Graphics System (PHIGS), Part 2, Archive File Format.
e. ANSI/ISO 9592.3:1989, Information Processing Systems--Computer
Graphics--Programmer's Hierarchical Interactive Graphics System
(PHIGS), Part 3, Clear Text Encoding of Archive File.
f. ANSI/ISO 9592.3a:1992, Amendment 1, Information Processing
Systems--Computer Graphics--Programmer's Hierarchical Interactive
Graphics System (PHIGS), Part 3, Clear Text Encoding of Archive File.
g. ANSI/ISO 9592.4:1992, Information Processing Systems--Computer
Graphics--Programmer's Hierarchical Interactive Graphics System
(PHIGS), Part 4, Plus Lumiere and Surfaces, PHIGS PLUS.
h. ANSI/ISO 9592.1:1990, Information Processing Systems--Computer
Graphics--Programmer's Hierarchical Interactive Graphics System
(PHIGS), Language Bindings, FORTRAN.
i. ISO/IEC 9593.1:1990 Tech. Corrigendum, Programmer's Hierarchical
Interactive Graphics System (PHIGS), Language Bindings, FORTRAN.
j. ANSI/ISO 9593.3:1990, Information Processing Systems--Computer
Graphics--Programmer's Hierarchical Interactive Graphics System
(PHIGS), Language Bindings, Ada.
k. ISO/IEC 9593.3:1990, Tech. Corrigendum, Programmer's
Hierarchical Interactive Graphics System (PHIGS) Language Bindings,
Ada.
l. ANSI/ISO 9593.4:1991, Information Processing Systems--Computer
Graphics--Programmer's Hierarchical Interactive Graphics System
(PHIGS), Language Bindings, C.
7. Related Documents.
a. Federal Information Resources Management Regulations (FIRMR)
subpart 201.20.303, Standards, and subpart 201.39.1002, Federal
Standards.
b. Federal ADP and Telecommunications Standards Index, U.S. General
Services Administration, Information Resources Management Service,
(updated periodically).
c. NIST, Validated Products List: Programming Languages, Database
Language SQL, Graphics, GOSIP, POSIX, Security, Published quarterly and
available by subscription from the National Technical Information
Service (NTIS), U.S. Department of Commerce, Springfield, VA 22161.
d. FIPS PUB 69-1, Programming Language FORTRAN, adopts ANSI X3.9-
1978/R1989.
e. FIPS PUB 119, Programming Language Ada, adopts ANSI/MIL-STD-
1815A-1983.
f. FIPS PUB 120-1, Graphical Kernel System (GKS), adopts ANSI
X3.124-1985.
g. FIPS PUB 128-1, Computer Graphics Metafile (CGM), adopts ANSI/
ISO 8632:1992.
h. FIPS PUB 160, Programming Language C, adopts ANSI/ISO 9899:
1992.
i. ANSI/ISO 8632:1992, Information Processing Systems--Computer
Graphics Metafile for the Storage and Transfer of Picture Description
Information (Part 1: Functional Specifications; Part 2: Character
Encoding; Part 3: Binary Encoding; Part 4: Clear Text Encoding).
j. ISO/IEC 646:1991, Information Processing--7-Bit Coded Character
Set for Information Interchange.
k. ISO 2022:1986, Information Processing--ISO 7-Bit and 8-Bit Coded
Character Sets--Code Extension Techniques.
l. ISO 2382/13:1984, Data Processing--Vocabulary--Part 13: Computer
Graphics.
m. ISO 6093:1985, Information Processing--Representation of Numeric
Values in Character Strings for Information Interchange.
n. ISO 7942:1985, Information Processing Systems--Computer
Graphics--Functional Specification of the Graphical Kernel System
(GKS).
o. ISO 7942/Amendment 1:1991, Computer Graphics--Graphical Kernel
Systems (GKS) Functional Descriptions.
p. ISO 8805:1988, Information Processing--Computer Graphics--
Graphical Kernel System (GKS-3D) Extensions Functional Description.
8. Objectives. The primary objectives of this standard are:
--To allow very highly interactive graphics application programs using
2D or 3D hierarchically structured graphics data to be easily
transported between installations. This will reduce costs associated
with the transfer of programs among different computers and graphics
devices, including replacement devices.
--To aid the understanding and use of dynamic hierarchical graphics
methods by application programmers.
--To aid manufacturers of graphics equipment by serving as a guideline
for identifying useful combinations of graphics capabilities in a
device.
--To encourage more effective utilization and management of graphics
application programmers by ensuring that skills acquired on one job are
transportable to other jobs, thereby reducing the cost of graphics
programmer retraining.
--To aid graphics application programmers in understanding and using
graphics methods by specifying well-defined functions and names. This
will avoid the confusion of incompatibility common with operating
systems and programming languages.
9. Applicability. PHIGS is one of the computer graphics standards
(Appendix A discusses the family of computer graphics standards)
provided for use by [[Page 5364]] all Federal departments and agencies.
These graphics standards should be used for all computer graphics
applications and programs that are either developed or acquired for
government use.
9.1 The FIPS for PHIGS is intended for use in computer graphics
applications that are either developed or acquired for government use.
It is specifically designed to meet the performance requirements of
such demanding applications as Computer Aided Design/Computer Aided
Engineering/Computer Aided Manufacturing, command and control,
molecular modelling, simulation and process control. It emphasizes the
support of applications needing a highly dynamic, highly interactive
operator interface and expecting rapid screen update of complex images
to be performed by the display system. The PHIGS PLUS functionality is
designed to support graphics applications requiring lighting and
shading, curved lines, curved and facetted surfaces, and non-indexed
color specification.
9.2 The use of this standard is compulsory and binding when one or
more of the following situations exist:
--The graphics application is very highly interactive, or contains
hierarchically structured graphics data, or requires rapid modification
of 2D or 3D graphics data and the relationships among the data.
--It is anticipated that the life of the graphics program will be
longer than the life of the presently utilized graphics equipment.
--The graphics application or program is under constant review for
updating of the specifications, and changes may result frequently.
--The graphics application is being designed and programmed centrally
for a decentralized system that employs computers of different makes
and models and different graphics devices.
--The graphics program will or might be run on equipment other than
that for which the program is initially written.
--The graphics program is to be understood and maintained by
programmers other than the original ones.
--The graphics program is or is likely to be used by organizations
outside the Federal government (i.e., State and local governments, and
others).
9.3 Nonstandard features of implementations of PHIGS should be
used only when the needed operation or function cannot reasonably be
implemented with the standard features alone. Although nonstandard
features can be very useful, it should be recognized that the use of
these or any other nonstandard elements may make the interchange of
graphics programs and future conversion more difficult and costly.
10. Specifications. American National Standard Programmer's
Hierarchical Interactive Graphics System, ANSI/ISO 9592.1-3:1989 and
ANSI/ISO 9592.1a,2a,3a,4:1992, define the scope of the specifications,
the syntax and semantics of the PHIGS elements and requirements for
conforming implementations. All of these specifications apply to
Federal Government implementations of this standard.
ANSI/ISO 9592.1-3:1989 and ANSI/ISO 9592.1a,2a,3a,4:1992 define a
language independent nucleus of a graphics system for integration into
a programming language. Thus, it is embedded in a language layer
obeying the particular conventions of the language. FIPS 153-1 is
therefore divided into two parts. Part 1 represents the functional
aspects of PHIGS. Part 1 consists of the following:
(1) Functional description (ANSI/ISO 9592.1:1989) and (ANSI/ISO
9592.1a:1992, Amendment 1)
The functional description of PHIGS provides a set of functions for
the definition, display and modification of 2D or 3D graphical data. It
also provides for the definition, display and manipulation of
geometrically related objects, along with the modification of graphics
data and the relationships between that graphical data.
(2) Archive file format (ANSI/ISO 9592.2:1989) and (ANSI/ISO
9592.2a:1992, Amendment 1)
The archive file provides a file format suitable for the storage
and retrieval of PHIGS structures and structure network definitions. It
allows structure definitions to be stored in an organized way on a
graphical software system. And, facilitates transfer of structure
definitions between different graphical software systems.
(3) Clear-text encoding (ANSI/ISO 9592.3:1989) and (ANSI/ISO
9592.3a:1992, Amendment 1)
The clear-text encoding provides a representative of the archive
file syntax that is easy to type, edit and read. The file is human-
readable (allows editing), human friendly (easy and natural to read)
and machine readable (parsable by software).
(4) Plus Lumiere and Surfaces, PHIGS PLUS (ANSI/ISO 9592.4:1992)
The Programmer's Hierarchical Interactive Graphics System (PHIGS)
Plus Lumiere and Surfaces (PHIGS PLUS) extends the basic PHIGS
functionality by adding facilities for the specification of curved
lines, curved and faceted surfaces, lighting and other effects such as
depth modulation.
Part 2 of FIPS 153-1 consists of the bindings of PHIGS and PHIGS
PLUS functions to actual programming languages, defined in ANSI/ISO
9593:1990. These bindings are developed in cooperation with the
voluntary standards committees of the various languages. The following
bindings currently exist, and form part 2 of FIPS 153-1:
--The FORTRAN Language binding for PHIGS (ANSI/ISO 9593.1:1990);
--The ADA Language binding for PHIGS (ANSI/ISO 9593.3:1990);
--The C Language binding for PHIGS (ANSI/ISO 9593.4:1991).
Subsequent language bindings, including those for PHIGS PLUS, will
be added periodically as they become available. As these bindings are
approved by ANSI, each language binding will become part of this
standard.
11. Implementation. Implementation of this standard involves four
areas of consideration: the effective date, acquisition of PHIGS
software system implementations, interpretations of PHIGS
implementations, and validation of PHIGS implementations.
11.1 Effective Date. This revised standard is effective August 1,
1995. Requirements for the use of basic PHIGS functionality (defined in
ANSI/ISO 9592.1-3:1989 and ANSI/ISO 9593.1:1990, 9593.3:1990,
9593.4:1991) are unchanged and continue in effect. Validation of PHIGS
implementations is required after the effective date in accordance with
Section 11.4.
11.2 Acquisition of Implementations. Conformance to FIPS for PHIGS
is required whether PHIGS toolbox packages are developed internally,
acquired as part of an ADP system procurement, acquired by separate
procurement, used under an ADP leasing arrangement, or specified for
use in contracts for programming services. Recommended terminology for
procurement of FIPS for PHIGS is contained in the U.S. General Services
Administration publication Federal ADP & Telecommunications Standard
Index, Chapter 4 Part 1.
11.3 Interpretation of this FIPS. NIST provides for the resolution
of questions regarding FIPS for PHIGS specifications and requirements,
and issues official interpretations as needed. Procedures for
interpretations are specified in FIPS PUB 29-3. All questions about the
interpretation of FIPS for PHIGS should be addressed to:
[[Page 5365]] Director, Computer Systems Laboratory (CSL), Attn: PHIGS
Interpretation, National Institute of Standards and Technology,
Gaithersburg, MD 20899, Telephone: (301) 975-3265.
11.4 Validation of PHIGS Implementations. Implementations of FIPS
for PHIGS using either FORTRAN or C bindings shall be validated in
accordance with NIST Computer Systems Laboratory (CSL) validation
procedures for FIPS for PHIGS. Recommended procurement terminology for
validation of FIPS for PHIGS is contained in the U.S. General Services
Administration publication Federal ADP & Telecommunications Standards
Index, Chapter 4 Part 2. This GSA publication provides terminology for
three validation options: Delayed Validation, Prior Validation Testing,
and Prior Validation. The agency shall select the appropriate
validation option. The agency is advised to refer to the NIST
publication Validated Products List for information about the
validation status of PHIGS products. This information may be used to
specify validation time frames that are not unduly restrictive of
competition.
The agency shall specify the criteria used to determine whether a
Validation Summary Report (VSR) or Certificate is applicable to the
hardware/software environment of the PHIGS implementation offered. The
criteria for applicability of a VSR or Certificate should be
appropriate to the size and timing of the procurement. A large
procurement may require that the offered version/release of the PHIGS
implementation shall be validated in a specified hardware/software
environment and that the validation shall be conducted with specified
hardware/software features or parameter settings; e.g., the same
parameter settings to be used in a performance benchmark. An agency
with a single-license procurement may review the Validated Products
List to determine the applicability of existing VSRs or Certificates to
the agency's hardware/software environment.
PHIGS implementations using either FORTRAN or C bindings shall be
validated using the NIST PHIGS Test Suite, a suite of automated
validation tests for PHIGS implementations. The NIST PHIGS Test Suite
was first released in July 1990 to help users and vendors determine
compliance with FIPS for PHIGS. The most recent version of the test
suite will be used for validating conformance of PHIGS implementations
after the effective date of FIPS PUB 153-1. The results of validation
testing by the PHIGS Testing Service are published on a quarterly basis
in the Validated Products List, available from the National Technical
Information Service (NTIS). See related documents section.
Each release of the test suite has provided additional language
bindings and test cases to increase the test suite's coverage of PHIGS
functionality. Version 2.1 of the NIST PHIGS Test Suite, released in
April 1994, provides testing for PHIGS implementations using either the
FORTRAN or C language binding. Version 2.1 does not include tests for
the functionality of PHIGS PLUS added by this revision of FIPS of
PHIGS.
A PHIGS Test Suite license includes all of the tests described
above, documentation, and automatic notifications of approved changes
to the PHIGS Test Suite for a six month period. A license for the most
recent version of the PHIGS Test Suite is a necessary requirement for
an organization that desires to be tested by the NIST PHIGS Testing
Service after the effective date of FIPS 153-1.
Current information about the NIST PHIGS Validation Service and
validation procedures for FIPS for PHIGS is available from: National
Institute of Standards and Technology, Computer Systems Laboratory,
Graphics Software Group, Building 225, Room A266, Gaithersburg, MD
20899, (301) 975-3265.
12. Waivers. Under certain exceptional circumstances, the heads of
Federal departments and agencies may approve waivers to Federal
Information Processing Standards (FIPS). The head of such agency may
redelegate such authority only to a senior official designated pursuant
to section 3506(b) of Title 44, United States Code.
Waivers shall be granted only when:
a. Compliance with a standard would adversely affect the
accomplishment of the mission of an operator of a Federal computer
system, or
b. Cause a major adverse financial impact on the operator which is
not offset by Governmentwide savings.
Agency heads may act upon a written waiver request containing the
information detailed above. Agency heads may also act without a written
waiver request when they determine that conditions for meeting the
standard cannot be met. Agency heads may approve waivers only by a
written decision which explains the basis upon which the agency head
made the required findings(s). A copy of each such decision, with
procurement sensitive or classified portions clearly identifed, shall
be sent to: National Institute of Standards and Technology; Attn: FIPS
Waiver Decisions, Technology Building, Room B-154; Gaithersburg, MD
20899. In addition notice of each waiver granted and each delegation of
authority to approve waivers shall be sent promptly to the Committee on
Government Operations of the House of Representatives and the Committee
on Governmental Affairs of the Senate and shall be published promptly
in the Federal Register.
When the determination on a waiver applies to the procurement of
equipment and/or services, a notice of the waiver determination must be
published in the Commerce Business Daily as a part of the notice of
solicitation for offers of an acquisition or, if the waiver
determination is made after that notice is published, by amendment to
such notice.
A copy of the waiver, any supporting documents, the document
approving the waiver and any supporting and accompanying documents,
with such deletions as the agency is authorized and decides to make
under 5 U.S.C. Sec. 552(b), shall be part of the procurement
documentation and retained by the agency.
13. Where to Obtain Copies. Copies of this publication are for sale
by the National Technical Information Service, U.S. Department of
Commerce, Springfield, VA 22161. (Sale of the included specifications
document is by arrangement with the American National Standards
Institute. When ordering, refer to Federal Information Processing
Standards Publication 153-1 (FIPSPUB153-1) and title. Payment may be
made by check, money order, or deposit account.
Appendix A--The Family of Graphics Standards
The following computer graphics standards are now available to
address the needs of government applications in creating, modifying,
manipulating, and exchanging computer-generated pictures:
FIPS PUB 120-1, the Graphical Kernel System (GKS), which
adopts ANSI X3.124-1985;
FIPS PUB 153-1, the Programmer's Hierarchical Interactive
Graphics System (PHIGS), which adopts ANSI/ISO 9592-1989;
FIPS PUB 128-1, the Computer Graphics Metafile (CGM),
which adopts ANSI/ISO 8632-1992 and
FIPS PUB 177, the Initial Graphics Exchange Specification
(IGES), which adopts ASME/ANSI Y14.26M-1989.
In addition, the Computer Graphics Interface (CGI) has recently
become an International standard, and is expected to be issued as a
FIPS. [[Page 5366]]
These standards fall into two categories: Application Programmer's
Interface (API) standards, and Interoperability standards. The goal of
API standards is to enhance the portability of graphics programs (and
programmers) between installations and environments. The goal of
Interoperability standards is to enable graphics data to be exchanged
successfully between graphics systems and devices.
Figure 1 is a very simple reference model of a computer graphics
operating environment. The model emphasizes that a graphics application
program interacts with physical devices and human operators via a
computer graphics environment. Figure 1 also shows that the application
may receive information from an external database.
The output of the graphics program, as shown in Figure 1, is
directed to a virtual graphics device (i.e., Virtual Device Interface
or VDI) rather than directly to a physical device. A Device Driver
provides an interface, implemented in either hardware or software, for
translating virtual device commands to commands understood by a
particular physical device. By substituting one device driver for
another, an application can run on a different physical device. This
device independence is a central concept of this graphics reference
model.
In Figure 1, the API standards reside in the box labelled the
Device Independent Graphics Package. Interoperability standards are
related to the boxes in Figure 1 labelled Metafile, Database and
Virtual Device Interface. Figure 2 depicts the various graphics
standards associated with the general model shown in Figure 1. These
are discussed below.
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Application Programmer's Interface (API) Standards
Standards at the API promote program and programmer portability. A
standard at this level specifies a set of operations on a variety of
graphics objects. An API standard provides for the portability of
applications across a wide range of computer hardware, operating
systems, programming languages, and graphics devices. A program written
to an API standard at one facility in one environment should be easily
transferable to another facility in a different environment. Facility
dependencies should be the major area requiring modification.
The specific functions supported by a particular API standard
provide certain capabilities. The application programmer, by
identifying the capabilities needed, determines the API better suited
for the application. As shown in Figure 2, there are currently two
graphics API standards, GKS and PHIGS.
GKS provides a functional description of a two-dimensional (2D)
graphics interface. It provides the basic graphics support required by
a wide variety of application requiring the production of computer-
generated pictures. A procedural language binding of a functional
standard specifies the exact name for each operation, its parameter
sequence, and the data types for the parameters. FORTRAN, Pascal, Ada
and C language bindings are parts of GKS.
GKS is suitable for use in graphics programming applications that
employ a broad spectrum of graphics, from simple passive graphics
output (where pictures are produced solely by output functions without
interaction with an operator) to interactive applications; and which
control a whole range of graphics devices, including but not limited to
vector and raster devices, microfilm recorders, storage displays,
refresh displays, and color displays.
PHIGS provides for the definition, display, modification, and
manipulation of 2D and graphical data. It provides functionality to
support storage of graphics and application data in a hierarchical
form. Information may be inserted, changed, and deleted from the
hierarchical data storage with the functions provided by PHIGS.
Language binding specifications for PHIGS include FORTRAN, C and Ada.
PHIGS is specifically designed to meet the performance requirements
of such demanding applications as Computer Aided Design/Computer Aided
Engineering/Computer Aided Manufacturing, command and control,
molecular modelling, simulation and process control.
Capabilities in PHIGS but not in GKS include: the centralized
hierarchical data storage; the dynamic and responsive nature of
interactions; the addition of a modeling capability; and support for
color models other than Red-Green-Blue (RGB).
Interoperability Standards
Graphics Interoperability standards allow graphical data to be
interchanged between graphics devices. As shown in Figure 2, there are
three graphics interoperability standards, CGM, (future) CGI, and IGES.
CGM is used for the storage and transfer of picture description
information. It enables pictures to be recorded for long term storage,
and to be exchanged between graphics devices, systems, and
installations. As indicated in Figure 2, the storage mechanism for CGM
is in the form of a neutral file format called a metafile. The software
which creates the metafile is known as a CGM Generator. The software
which reads and displays a CGM metafile is known as an Interpreter.
CGM specifies a semantic interface that describes 2D graphical
entities using primitives (like polyline, text, and ellipse) and
attributes (like color, line width, interior style, and fonts). CGM is
compatible with the specification of 2D elements in GKS. A data
encoding specifies the exact sequence of bits used to represent each
operation and its parameters. CGM contains three types of data stream
encodings (binary, character, and clear text) to provide the
implementor choices depending on the particular application.
IGES provides a method for representing and storing geometric,
topological, and non-geometric product definition data that is
independent of any one system. Where CGM transfers graphical pictures,
IGES transfers a graphical database which can be processed to represent
a picture. Thus IGES represents more than just purely graphical data.
As Figure 2 indicates, the storage mechanism for IGES is in the form of
a neutral format that must be translated by a Preprocessor and
Postprocessor for conversion between systems. IGES permits the
compatible exchange of product definition data used by various computer
aided design/computer aided manufacturing (CAD/CAM) systems.
The future CGI standard is designed to specify the exchange of
information at the Virtual Device Interface. It will provide an
interface between the device independent and device dependent parts of
a graphic system. Since CGI contains information at a vitual level, it
can be used to create a CGM. A CGM can also be output on a CGI device
in a straightforward manner.
[FR Doc. 95-2103 Filed 1-26-95; 8:45 am]
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