BS ISO IEC 11072-1993 Information Technology - Computer graphics - Computer Graphics Reference Model《信息技术 计算机制图 计算机制图参考模型》.pdf

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1、BSI BS*ISO/IEC 11072 92 W 1b24bb9 0332662 TT BRITISH STANDARD o 2- J r - . Implementation of ISO/IEC 11072 : 1992 Information technology - Computer graphies - Computer Graphies Reference Model BS ISO/IEC 11072 : 1992 BSI BS*ISO/IEC 11072 92 = 1624bb9 0332bb3 b BS ISO/IEC 11072 : 1992 National forewo

2、rd This British Standard reproduces verbatim ISO/IEC 11072 : 1992 and implements it as the UK national standard. This British Standard is published under the direction of the Information Systems Technology Standards Policy Committee whose Technical Committee IST/3 1 has the responsibility to: - aid

3、enquirers to understand the text; - present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; - monitor related international and European developments and promulgate them in the UK. NCYIE. International and European

4、Standards, as well as overseas standards, are available from BSI Sales Department, BSI, Linford Wood, Milton Keynes, MI(14 6LE. Compliance with a British Standard does not of itself confer immunity from legal obligations. I BSI BS*ISO/IEC 11072 92 W 1624669 0332664 842 W INTERNATIO IAL STANDARD ISOA

5、EC 11 072 First edition 1992-1 0-01 Information technology - Computer graphics - Computer Graphics Reference Model Technologies de linformation - Infographie - Modle de rfrence Reference number ISO/IEC 11072:1992 (E) - BSI BS*ISO/IEC LLO2 92 = ISOiEC 11072:1992 (E) Contents Foreword Introduc tion 1

6、Scope 2 Definitions 3 The Computer Grapu,s Reference ,adel 3.1 Environment model 3.2 External 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 element

7、s 3.5.1 Absorption 3.5.2 Manipulation 3.5.3 Distribution 3.5.4 Assembly 3.5.5 Emanation 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 3.6 Characteristics of specific environments 3.7 Relationship between output an

8、d input 3.8 Internal interfaces Lb24669 0332665 789 W Page iv 1 2 7 7 8 9 11 11 11 11 11 12 12 12 12 13 13 13 13 14 14 16 16 17 18 18 20 21 v O ISO/IEC 1992 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including

9、 photocopying and microfilm, without permission in writing from the publisher. ISOAEC Copyright Office Case postale 56 CH-121 1 Genve 20 Switzerland Printed in Switzerland ii - ES1 BS*ISO/IEC LI1072 92 M Lb2qbb9 0332666 bL5 M ISO/EC 11072:1992 (E) Annexes A Existing standards and the CGRM A. 1 Graph

10、ical kernel system-IS0 7942 A.2 Graphical kernel system for three dimensions-IS0 8805 A. 3 Programmers hierarchical interactive graphics system - ISOAEC 9592 A.4 Interfacing techniques for dialogues with graphical devices-ISO/IEC 9636 AS Metafile for the storage and transfer of picture description i

11、nformation-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 C. 3 Windowing considered as an operator C. 4 Windowing considered as part of the computer graphics system C.4.1 Overview C.4

12、.2 Operations on windows C.4.3 Operations on window content (2.4.4 Displaying windows C.4.5 Input D Bibliography 22 22 22 24 24 26 27 30 30 30 30 32 32 33 33 34 34 35 iii BSI BS*ISO/IEC 11072 92 W bb24bb 0332bb7 551 ISO/IEC 11072:1992 (E) Foreword IS0 (the International Organization for Standardizat

13、ion) and IEC (the international Electrotechnical Commission) form the specialized system for 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

14、deal with particular fields of technical activity. IS0 and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with IS0 and IEC, also take part in the work. In the field of information technology, IS0 and

15、 IEC have established a joint technical committee, ISOAEC JTC 1. Draft International Standards adopted 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. Int

16、ernational Standard ISOAEC 11072 was prepared by Joint Technical Committee ISO/IEC JTC 1, Injbrmtion technofogy, iv Annexes A to D of this International Standard are for information only. BSI BS*ISO/IEC 11072 92 M 1624669 0332668 498 M ISOAEC 11072:1992 (E) Introduction The Computer Graphics Referen

17、ce Model (CGRM) describes the conceptual framework for computer graphics. Computer graphics is the creation of, manipulation of, analysis of, and interaction with pictorial representations of objects and data using computers. The main purpose of the CGRM is to define concepts that shall be used to d

18、evelop computer graphics standards. Additional purposes are to explain relations between SC24 standards and to provide a forum whereby areas outside computer graphics can identi their relationships to computer graphics. Intemational Standards related to computer graphics include the foliowing existi

19、ng and emerging areas: a) Open Systems Interconnection - Basic Reference Model; b) Virtual Terminal Protocols and Terminal Management; c) File Transfer, Access and Management Protocols; d) Office Document Architecture and Interchange; e) Text and Office Systems; f) Exchange of Product Model Data; g)

20、 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 wiil ensure their long term coherence based on objective rational foundations. Existing

21、computer graphics standards will not necessarily fit precisely into the Reference Model. However, experience with current standards has significantly influenced the model. V BSI BS*ISO/IEC i11072 9Z W 3624bb9 O332669 324 INTERNATIONAL STANDARD ISOAEC 11072:1992 (E) Information technology - Computer

22、graphics - Computer Graphics Reference Model 1 Scope This International Standard, the Computer Graphics Reference Model (CGRM), defines a sructure within which current and future International Standards for computer graphics shall be compared and their relationships described, This Intemational Stan

23、dard 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 refe requirements for computer graphics; b) identify needs for computer graphics standards

24、 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 graphics standards shall be defined and developed.

25、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 implementation specification for systems incorporating co

26、mputer graphics, nor a basis for appraising the conformance of implementations. 1 BSI BS*ISO/IEC 11072 92 Lb24669 0332670 046 W 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 clau

27、se. 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 comput

28、er 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 given

29、 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 that

30、interfaces to the application. 2.4.2 virtual environment: The environment between the construction and viewing 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 env

31、ironments. 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 b

32、etween 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. 2.4.1 O fan-out: The generation

33、 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

34、ture metafile and audit trail metdile. BSI BS*ISO/IEC 11072 92 m lb24669 O332671 - T82 m - ISO/IEC 11072:1992 w) 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 in

35、terface: The interface provided by the construction 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.

36、3.1 export: The process of generating a data capture metafiie. 2.5.3.2 import: The action of setting part or all of a data element from a data capture metafiie. 2.5.4 audit trail metafile: An external object for representing the sequential flow of information across the application interface. 2.6 pr

37、ocessing element: A process in an environment: absorption, 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 e

38、nvironment level: preparation, production, projection, completion and presentation. 2.6.1.1 preparation: The name given to absorption in the construction environmen t. 2.6.1.2 production: The name given to absorption in the virtual environmen t. 2.6.1.3 projection: The name given to absorption in th

39、e viewing environmen t. 2.6.1.4 completion: The name given to absorption in the logical environmen t. 2.6.1.5 presentation: The name given to absorption in the realization environmen t. 2.6.2 emanation: A process which emanates token store and input control entities to the next higher environment af

40、ter processing them. Specific names are given to emanation at each environment level: accumulation, abstraction, elevation, generation and utilization. 2.6.2.1 accumulation: The name given to emanation in the realization environmen t. 2.6.2.2 abstraction: The name given to emanation in the logical e

41、nvironment. 2.6.2.3 elevation: The name given to emanation in the viewing environmen t. 2.6.2.4 generation: The name given to emanation in the virtual environmen t. 3 BSI BS*ISO/IEC LI1072 92 Lb2Yb69 0332672 919 = I 2.6.2.5 utilization: The name given to emanation in the construction environmen t. 2

42、.6.3 distribution: A process which distributes the composition and output control entities 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

43、 contents of data elements. 2.7 data element: A store in an environment: composition, 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 eac

44、h environment level: model, scene, picture, graphical image and display. 2.7.1.1 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 en

45、vironment. 2.7.1.4 graphical image: The name given to the composition in the logical environmen t. 2.7.1.5 display: The name given to the composition in the realization environment. I 2 7.2 collection store: A storage facility for collections. 2.7.2.1 collection: A set of output entities which are n

46、amed and may be structured. A collection may be manipulated to produce all or part of a composition in the same environment. 2.7.3 aggregation store: A storage facility for aggregations. 2.7.3.1 aggregation: A set of input entities which are named and may be structured. An aggregation may be manipul

47、ated to produce one or more input tokens in the token store in the same environment. 2.7.4 token store: A structured set of input tokens in a given environment. Specific names are given to the token store at each environment: lexeme store, information store, selection store, directive store and inst

48、ruction store. 2.7.4.1 lexeme store: The name given to the token store in the realization environmen t. 2.7.4.2 information store: The name given to the token store in the logical environment. 4 BSI BS*ISO/IEC iILO72 92 W iI624669 0332673 855 I ISO/IEC 11072:1992 (E) 2.7.4.3 selection store: The nam

49、e given to the token store in the viewing environment, 2.7.4.4 directive store: The name given to the token store in the virtual environment. 2.7.4.5 instruction store: The name given to the token store in the construc tion environment. 2.7.5 environment state: Entities in the environment separate from other data elements: composition, collection store, token store, aggregation store. 2.7.6 editing: The change of entities within data elements in an environment. 2.8 output primitive: An atomic unit for graphical output in a given environment, There may be more than