ANSI ISO IEC 9637-1-1994 Information Technology - Computer Graphics - Interfacing Techniques for Dialogues with Graphical Devices (CGI) - Data Stream Binding Part 1 Character Encod.pdf

1、INCITS/ISO/IEC 9637-1-1994(R1999)(formerly ANSI/ISO/IEC 9637-1-1994 (R1999)for Information Technology -Computer Graphics -Interfacing Techniques forDialogues with GraphicalDevices (CGI) -Data Stream BindingPart 1: Character EncodingAmericanNationalStandardApproval of an American National Standard re

2、quires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen 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 materiallyaffecte

3、d interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Consensus 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 exi

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5、tances give an interpretation of any American National Standard.Moreover, no person shall have the right or 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 secretaria

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7、. Purchasers of American National Standards may receive currentinformation on all standards by calling or writing the American National StandardsInstitute.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1994 by Information Technology Industry C

8、ouncil (ITI)All rights reserved.These materials are subject to copyright claims of International Standardization Organization (ISO),International Electrotechnical Commission (IEC), American National Standards Institute (ANSI), andInformation Technology Industry Council (ITI). Not for resale. No part

9、 of this publication may bereproduced in any form, including an electronic retrieval system, without the prior 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 AmericaANSI/ISO/I EC 9

10、637-l -1994 American National Standard for Information Technology - Computer Graphics - Interfacing Techniques for Dialogues with Graphical Devices (CGI) - Data Stream Binding Part 1: Character Encoding Secretariat Computer and Business Equipment Manufacturers Association Approved August 18, 1994 Am

11、erican National Standards Institute, Inc. Contents 00.: 0:3 1 2 3 X-8 312.1 3.2.2 3.2.3 t.1 t*i 1 4:2:2 4.3 t.1 66: :*t 6:6 6.6.1 6.6.2 6.6.3 6.7 :*ss 1 6:8:2 6.8.3 6.8.4 Foreword . iv Introduction . vi Purpose of the character encoding . Vl Obectives i vi Re ationship to other International Standar

12、ds . vi Scope . 1 Normative references 2 Notational conventions . 3 7-Bit and 8-Bit code tables 3 ($e;stiension techniques vocabulary . i Cl sets G sets 4” Overall structure 6 General form of the data stream . Entering and leaving the CGI environment . : Implicitly entering the CGI environment . Des

13、ignating and invoking the CGI coding environment from IS0 2022 ii Encoding functions 6 Method of encoding opcodes . 8 Encoding technique of the basic opcode set . 8 Extension mechanism 9 Opcode assignments Opcodes for soliciting functions z Method of encoding parameters . Basic format . 2$ Bitstream

14、 format . Coding integers (I, IFS, IF16, IF32). . ; Coding real numbers (R) . 23 Coding Virtual Device Coordinates and Points (VDC, P) 25 Coding point list parameters (nP) . 26 Displacement mode 26 Incremental mode 26 Incremental mode encoding 31 Colour specifiers (CI, CD). . 31 Colour lists (nC1, n

15、CD1 32 Normal format (coding type=01 . 33 Bitstream format (coding type=11 . 33 Runlength format (coding type=2) 34 Runlength bitstream format (coding type=31 . 34 6.8.5 i*; 1 6:9:2 6.9.3 6.9.4 6.9.4.1 6.9.4.2 6.10 6.11 6.12 6.13 6.14 Examples 34 String lf arameters (S, SF) . 36 Overa string paramet

16、er format 36 Bit combinations permitted within string parameters of text functions 36 CO control within string parameters 37 Using G-sets in string parameters 37 String parameters and character sets 37 String parameters of other CGI functions 38 Enumerated parameters (E) . 38 Index parameters (IX) .

17、 39 Client specified name parameters (CSN) . 39 Input colour parameters (ICO, nIC0). Data record parameters (D) “4: 7 z.1 i-i a:3.1 8.3.2 8.3.3 8.3.4 8.3.5 8.3.6 8.3.7 8.3.8 8.3.9 8.4 Character substitution 42 Representation of CGI functions 44 Soliciting functions Enumerated parameters . 2 Function

18、s not specified in ISO/IEC 9636 . 45 DOMAIN RING 45 INTEGER PRECISION . 45 REAL PRECISION 46 INDEX PRECISION 46 COLOUR PRECISION 47 COLOUR INDEX PRECISION . 47 VDC INTEGER PRECISION 47 VDC REAL PRECISION . 47 CLIENT SPECIFIED NAME PRECISION 48 Encoding of matrices . 48 9 Defaults . 50 10 Classificat

19、ion and designation 51 Annex A: List of CGI Opcodes 52 Annex B: List of escape sequences 63 . . . 111 Foreword (This foreword is not part of American National Standard ANSI/ISO/IEC 9637-l - 1994. This document is identical to ISO/IEC 9637-l-l 994 and the following five paragraphs are the original fo

20、reword as it appeared in that document.) IS0 (the International Organization for Standardization) 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 Intern

21、ational Standards through technical committees established by the respective organization to deal with particular fields of technical activity. IS0 and IEC technical commit- tees collaborate in fields of mutual interest. Other international organiza- tions, governmental and non-governmental, in liai

22、son 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 Standards adopt- ed by the joint technical committee are circulated to national bodies for voting. Publication as an

23、International Standard requires approval by at least 75% of the national bodies casting a vote. International Standard ISO/IEC 9637-l was prepared by Joint Technical Committee ISO/IEC JTC 1, information technology, Sub-Committee SC 24, Computer graphics and image processing, in collaboration with th

24、e European Computer Manufacturers Association (ECMA) and the European Conference of Postal and Telecommunications Administration (CEPT). ISO/IEC 9637 consists of the following parts, under the general title Information technology - Computer graphics - Interfacing techniques for dialogues with graphi

25、cal devices (CGI) - Data stream binding: - Part 1: Character encoding - Part 2: Binary encoding - Part 3: Clear text encoding Annexes A and B of this part of ISO/IEC 9637 are for information only. Requests for interpretation, suggestions for improvement or addenda, or defect reports are welcome. The

26、y should be sent to the X3 Secretariat, Computer and Business Equipment Manufacturers Association, 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 a

27、pproval of the standard does not necessarily imply that all committee members voted for its approval. 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

28、Representative American Nuclear Society . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geraldine C Main Sally Hartzell (Alt ) AMP, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Edward Kelly Charles Brill (Alt.) Apple Computer, Inc. , . . . . . . . . . . . . . . . . .

29、. . . . . . . . . . . . . . . . . . . . . . . Karen Higginbottom iv Organization Represented Name of Representative AT b) compactness: the encoding provides a highly compact data stream, suitable for systems with restricted storage capacity or transfer bandwidth, c) extensibility: the encoding allow

30、s for future extensions; d) transportability: the encoding is suitable for use with transport mechanisms designed for character-oriented data based on a standard national character set derived from ISO/IEC 646. 0.3 Relationship to other International Standards The character encoding has been develop

31、ed in collaboration with the ISO/EXC JTClBC2. The en- coding conforms to the rules for code extension specified in IS0 2022 in the category of complete coding system. The representation of character data in this part of ISO/IEC 9637 follows the rules of ISO/IEC 646 and IS0 2022. For certain function

32、s, ISO/IEC 9636 defines value ranges as being reserved for registration. The values and their meanings will be defined using the established registration procedures (see ISO/IEC 9636-l). This encoding is based on that for the Computer Graphics Metafile ISOAEC 8632-2. Wherever pos- sible, the opcodes

33、 and parameter representations of CGM elements have been followed. vi AMERICAN NATtONAL STANDARD ANSt/ISO/IEC 9637-1-1994 American National Standard for Information Technology - Computer Graphics - Interfacing Techniques for Dialogues with Graphical Devices (CGI) - Data Stream Binding Part 1: Charac

34、ter Encoding 1 Scope This part of ISO/IEC 9637 specifies a character encoding of the Computer Graphics Interface. For each of the functions specified in ISO/IEC 9636 an encoding is specified. This encoding of the Computer Graphics Interface provides a highly compact representation of the data, suita

35、ble for applications that require the data to be of minimum size and suitable for trans- mission with character-oriented transmission services. 1 (8 ISOAEC CGI Character Encoding ISO/IEC 9637-1:1994 (E) 2 Normative references 2 Normative references The following standards contain provisions which, t

36、hrough reference in this text, constitute provi- sions of this part of ISO/IEC 9637. At the time of publication the editions indicated were valid. Ah standards are subject to revision, and parties to agreements based to this part of ISO/IEC 9637 are encouraged to investigate the possibility of apply

37、ing the most recent editions of the standards listed below. Members of IS0 and IEC maintain registers of currently valid international standards. ISO/IEC 646:1991, IS0 2022:1986, IS0 23751985, ISO/IEC 6429:1992, IS0 7942:1985, ISOIIEC 8632-2:1992, ISOLIEC 9636-1:1991, ISO/IEC 9636-2:1991, ISO/IEC 96

38、36-3:1991, ISO/IEC 9636-4:1991, ISO/IEC 9636-51991, ISO/IEC 9636-6:1991, ISOLIEC 9637-2:1992, Information technology - IS0 7-bit coded character set for information in- terchange. Information processing - IS0 7-bit and 8-bit coded character sets - Coded extension techniques. Data processing - Proced

39、ure for registration of escape sequences. Information technology - Control functions fix coded character sets. Information processing systems - Computer graphics - Graphical Kernel System (GKS) functional description. Information technology - Computer graphics - Metafile for the storage and transfer

40、 of picture description information - Part 2 : Character encoding, Information technology - Computer graphics - Interfacing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 1: Overview, profiles and conformance. Information technology - Computer graphics - Inte

41、rfacing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 2: Control. Information technology - Computer graphics - Interfacing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 3: output. Information technology - Computer gr

42、aphics - Interfacing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 4: Segments. Information technology - Computer graphics - Interfacing techniques for dialogues with graphical devices (CGI) - Functional specification - Part 5: Input and echoing. Information

43、 technology - Computer graphics - Interfacing techniques for dialogues with graphical devices (CGI) - Functional specifiation - Part 6: Raster. Information technology - Computer graphics - Interfacing techniques for dialogues with graphical devices (CGI. - Data stream binding - Part 2: Bi- nags enco

44、ding. ISO/IEC TR 9973:1988, Information processing - Procedures for Registration of Graphical Items. ECMA 96, Graphics Data Syntax for a multiple Workstation Interface. CEPT, Rev. of T/ CD 6.1 Videotex Presentation Layer Data Syntax. 2 0 ISO/IEC CGI Character Encoding ISOAEC 9637-1:1994 (E) 3 Notati

45、onal conventions 3 Notational conventions 3.1 7-Bit and - y is the number represented by b4, b3, b2, and bl where these bits are given the weights 8, 4,2, and 1 respectively. The notations of the form x/y are the same as those used to identify code table positions, where f: is the column number and

46、y is the row number. A 7-bit code table consists of 128 positions arranged in eight columns and sixteen rows. The col- umns are numbered 0 to 7 and the rows are numbered 0 to 15. Figure 1 shows a 7-bit code table. An example illustrates the I-bit code: l/11 refers to the bit combination in column 1,

47、 row 11 of the code table, binary 0011011. The bits of the bit combinations of the 8-bit code are identified by b8, b7, b6, b5, b4, b3, b2, and bl, where b8 is the highest-order, or most-significant, bit and bl is the lowest-order, or least- significant, bit. The bit combinations may be interpreted

48、to represent integers in the range 0 to 255 in binary nota- tion by attributing the following weights to the individual bits: Using these weights, the bit combinations of the 8-bit code are interpreted to represent numbers in the range 0 to 255. In this part of ISO/IEC 9637 the bit combinations of a

49、n 8-bit code are identified by notation of the 3 ISO/IEC 9637.1:1994 0s) 0 ISO/IEC 3 Notational conventions CGI Character Encoding form xzlyy, where 3cz and w are numbers in the range 00 to 15. The correspondence be-een the notations of the form pelyy and the bit combinations consisting of the bits b8 to bl is as follows: - xz is the number represented by b8, b7, b6, and b5 where these bits are given the weights 8, 4,2, and 1 respectively; - m is the number represented by b4, b3, b2, and bl where these bits are given the weights 8, 4,2, and 1 respectively. The notations of the form zzly