1、 INCITS/ISO/IEC 11072-1992 (R1999)(formerly ANSI/ISO/IEC 11072-1992 (R1999)for Information Technology -Computer Graphics -Computer GraphicsReference ModelANSIIISOIIEC 11072-l 992 American National Standard for Information Technology - Computer Graphics - Computer Graphics Reference Model Secretariat
2、 Computer and Business Equipment Manufacturers Assoclatlon Approved May 12,1994 American Natlonal Standards Institute, Inc. AmericanNationalStandardApproval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for approval haveb
3、een met by the standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffected interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Con
4、sensus requires that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely voluntary; their existencedoes not in any respect preclude anyone, whether he has approved the standardsor not, from manufacturi
5、ng, marketing, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will inno circumstances give an interpretation of any American National Standard.Moreover, no person shall have the right or
6、authority to issue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed to the secretariat orsponsor whose name appears on the title page of this standard.CAUTION NOTICE: This American National Sta
7、ndard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive currentinformation on all standards by calling or wr
8、iting the American National StandardsInstitute.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1992 by Information Technology Industry Council (ITI)All rights reserved.These materials are subject to copyright claims of International Standardiza
9、tion Organization (ISO),International Electrotechnical Commission (IEC), American National Standards Institute (ANSI), andInformation Technology Industry Council (ITI). Not for resale. No part of this publication may bereproduced in any form, including an electronic retrieval system, without the pri
10、or written permission of ITI.All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW, Washington, DC20005.Printed in the United States of AmericaContents Foreword Introduction 1 scope 2 Definitions 3 The Computer Graphics Reference Model 3.1 Environment model 3.2 Exte
11、rnal relationships 3.3 Environment structure 3.4 Data elements 3.4.1 Introduction 3.4.2 Composition 3.4.3 Collection store 3.4.4 Token store 3.4.5 Aggregation store 3.4.6 Environment state 3.5 Processing elements 3.5.1 Absorption 3.5.2 Manipulation 3.5.3 Distribution 3.5.4 Assembly 3.5.5 Emanation 3
12、.6 Characteristics of specific environments 3.6.1 Environment details 3.6.2 Output primitives 3.6.3 Input tokens 3.6.4 Properties 3.6.5 Transformations 3.6.6 Fan-in and fan-out 3.7 Relationship between output and input 3.8 Internal interfaces Page iii V :. : ; 11 11 11 11 11 12 12 12 12 13 13 13 13
13、14 14 16 16 17 18 : 21 Annexes A Existing standards and the CGRM A.1 Graphical kernel system-IS0 7942 A.2 Graphical kernel system for three dimensions-IS0 8805 A.3 Programmers hierarchical interactive graphics system - ISO/IEC 9592 A.4 Interfacing techniques for dialogues with graphical devices-ISO/
14、IEC 9636 A.5 Metafile for the storage and transfer of picture description information-IS0 8632 B The relationship of computer imaging to computer graphics C The relationship of window systems to computer graphics c.1 Introduction C.2 Window systems m C. 3 Windowing considered as an operator C.4 Wind
15、owing considered as part of the computer graphics system C.4.1 Overview C.4.2 Operations on windows C.4.3 Operations on window content =- C.4.4 Displaying windows C.4.5 Input D Bibliography 222 22 24 24 26 27 ;: 30 30 32 Foreword (This foreword is not part of American National Standard ANSMSO/lEC 11
16、 OM- 1992. This document is identical to ISO/IEC 11072-l 992 and the following four paragraphs are the original foreword as it appeared in that document.) IS0 (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for
17、worldwide standardization. National bodies that are members of IS0 or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. IS0 and IEC technical commit- tees collabo
18、rate in fields of mutual interest. Other international organiza- tions, governmental and non-governmental, in liaison with IS0 and IEC, also take part in the work. In the field of information technology, IS0 and IEC have established a joint technical committee, ISO/IEC JTC 1. Draft International Sta
19、ndards adopt- ed by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75% of the national bodies casting a vote. International Standard ISO/IEC 11072 was prepared by Joint Technical Committee ISO/IEC JTC
20、 1, information Technology. Annexes A to D of this International Standard are for information only. Requests for interpretation, suggestions for improvement or addenda, or defect reports are welcome. They should be sent to the X3 Secretariat, Computer and Business Equipment Manufacturers Association
21、, 1250 Eye Street, NW, Suite 200, Washington, DC 20005. This standard was processed and approved for submittal to ANSI by Accredited Standards Committee on Information Processing Systems, X3. Committee approval of the standard does not necessarily imply that all committee members voted for its appro
22、val. At the time it approved this standard, the X3 Committee had the following members: James D. Converse, Chair Donald C. Loughry, Vice-Chair Joanne Flanagan, Secretary Organization Represented Name of Representative Apple Computer, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23、 . . . . . . . . . . . . . . . . . . . . . . . . . . Karen Higginbottom American Nuclear Society . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geraldine C. Main Sally Hartzell (Alt.) AMP, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . .
24、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Edward Kelly Charles Brill (Alt.) AT b) Virtual Terminal Protocols and Terminal Management; c) File Transfer, Access and Management Protocols; d) Office Document Architecture and Interchange; e) Text and O
25、ffice Systems; f) Exchange of Product Model Data; g) Character Sets and Coding; h) Open Distributed Processing; i) Image Processing and Interchange. This International Standard shall be the basis for the development of specific standards for computer graphics and will ensure their long term coherenc
26、e based on objective rational foundations. Existing computer graphics standards will not necessarily fit precisely into the Reference Model. However, experience with current standards has significantly influenced the model. I AMERICAN NATIONAL STANDARD ANSVlSOllEC 11072-l 992 American National Stand
27、ard for Information Technology - Computer Graphics - Computer Graphics Reference Model 1 Scope This International Standard, the Computer Graphics Reference Model (CGRM), defines a structure within which current and future International Standards for computer graphics shall be compared and their rela
28、tionships described. This International Standard defines a set of concepts and their inter-relationships which should be applicable to the complete range of future computer graphics standards. This International Standard may be applied to: - a) verify and refine requirements for computer graphics; b
29、) identify needs for computer graphics standards and external interfaces; c) develop models based on requirements for computer graphics; d) define the architecture of new computer graphics standards; e) compare computer graphics standards. This International Standard does not define how computer gra
30、phics standards shall be defined and developed. It does not specify the functional descriptions of computer graphics standards, the bindings of those standards to programming languages, or the encoding of graphical information in any coding technique or interchange format. It is neither an implement
31、ation specification for systems incorporating computer graphics, nor a basis for appraising the conformance of implementations. 1 ISO/IEC 11072: 1992 (E) 2 Definitions For the purposes of this International Standard, the following definitions apply. An alphabetical list is given at the end of this c
32、lause. 2.1 computer graphics: The creation of, manipulation of, analysis of and interaction with pictorial representations of objects and data using computers. 2.2 application: The external object that uses computer graphics. Applications are not modelled in the CGRM, but their interactions with com
33、puter graphics are modelled. 2.3 operator: The external object that observes the contents of the display and generates physical input values. Operators are not modelled in the CGRM, but their interactions with computer graphics systems are modelled. 2.4 environment: A subdivision of the CGRM at a gi
34、ven level of abstraction. The definition of the environment includes the definition of its data elements and processing elements. Specific names are given to the five environments: construction, virtual, viewing, logical and realization (see 3.6.1). 2.4.1 construction environment: The environment th
35、at interfaces to the application. 2.4.2 virtual environment: The environment between the construction and *wing environments. 2.4.3 viewing environment: The environment between the virtual and logical environments. 2.4.4 logical environment: The environment between the viewing and the realization en
36、vironments. 2.4.5 realization environment: The environment that interfaces to the operator. 2.4.6 higher environment: An environment closer to the application. 2.4.7 lower environment: An environment closer to the operator. 2.4.8 entity: An item of information stored within an environment or passed
37、between environments. Entities are divided into three classes: input, output and control. 2.4.9 fan-in: The merging of entities from multiple, independent sources to produce a single stream (without changing individual entities) to be processed by a single environment. 2.4.10 fan-out: The generation
38、 of multiple, independent entities from a single entity without change. The generated entities are sent to independent environments. 2.5 external interfaces: The interfaces between the computer graphics system and the outside world, the interfaces communicate with the operator, application, data cap
39、ture metafile and audit trail metafile. 2 ISO/IEC11072:1992(E) - 2.5.1 operator interface: The interface between the realization environment and the operator. This is the only interface between the operator and the graphics system. 2.5.2 application interface: The interface provided by the construct
40、ion environment to the application. This is the only interface between the application and the graphics system. 2.5.3 data capture metafile: An external object for representing all or part of a data element for storage, retrieval and transmission. 2.5.3.1 export: The process of generating a data cap
41、ture metafile. 2.5.3.2 import: The action of setting part or all of a data element from a data capture metafile. 2.5.4 audit trail metafile: An external object for representing the sequential flow of information across the application interface. 2.6 processing element: A process in an environment: a
42、bsorption, manipulation, distribution, assembly, and emanation. 2.6.1 absorption: A process which receives entities from the next higher environment and processes them for use within its own environment. Specific names are given to absorption at each environment level: preparation, production, proje
43、ction, completion and presentation. 2.6.1.1 preparation: The name given to absorption in the construction environment. 2.6.1.2 production: The name given to absorption in the virtual environment. 2.6.1.3 projection: The name given to absorption in the viewing environment. 2.6.1.4 completion: The nam
44、e given to absorption in the logical environment. 2.6.1.5 presentation: The name given to absorption in the realization environment. 2.6.2 emanation: A process which emanates token store and input control entities to the next higher environment after processing them. Specific names are given to eman
45、ation at each environment level: accumulation, abstraction, elevation, generation and utilization. 2.6.2.1 accumulation: The name given to emanation in the realization environment. 2.6.2.2 abstraction: The name given to emanation in the logical environment. 2.6.2.3 elevation: The name given to emana
46、tion in the viewing environment. 2.6.2.4 generation: The name given to emanation in the virtual environment. 3 ISO/IEC 11072:1992 (E) 2.6.2.5 utilization: The name given to emanation in the construction environment. 2.6.3 distribution: A process which distributes the composition and output control e
47、ntities to the next lower environment. 2.6.4 assembly: A process which receives entities from the next lower environment for use within its own environment. 2.6.5 manipulation: A process which accesses and changes the contents of data elements. 2.7 data element: A store in an environment: compositio
48、n, collection store, token store, aggregation store, and environment state. 2.7.1 composition: A spatially structured set of output primitives in a given environment. Specific names are given to the composition at each environment level: model, scene, picture, graphical image and display. _ 2.7.1.1
49、model: The name given to the composition in the construction environment. 2.7.1.2 scene: The name given to the composition in the virtual environment. *- 2.7.1.3 picture: The name given to the composition in the viewing environment. 2.7.1.4 graphical image: The name given to the composition in the logical environment. 2.7.1.5 display: The name given to the composition in the realization environment. 2.7.2 collection store: A storage facility for collections. 2.7.2.1 collection: A set of output entities which are named and may be structured. A collection may be manipulated to produce
