1、BRITISH STANDARD Information technology - Computer graphics and image processing - Graphical Kernal System (GKS) - Part 1: Functional description ICs 35.140 BS ISODEC 7942-1:1994 BS ISO/IEC 7942-1:1994 Amd. No. National foreword Date Comments This British Standard reproduces verbatim ISO/IEC 7942- 1
2、:1994 and implements it as the UK national standard. It supersedes BS EN ISO/IEC 7942-1:1996 which is already withdrawn. The UK participation in its preparation was entrusted to Technical Committee IST/31, Computer Graphics and Image Processing, which has the responsibility to: - - aid enquirers to
3、understand the text; present to the responsible internationalEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represent
4、ed on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled ?International Standards Correspondence
5、Index?, or by using the ?Find? facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itsel
6、f confer immunity from legal obligations. This British Standard, having been prepared under the direction of the DISC Board, was published under the authority of the Standards Policy and Strategy Committee on 1 November 2001 Summary Of pages This document comprises a front cover, an inside front cov
7、er, ISO/IEC title page, pages ii to x, pages 1 to 164, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. O BSI 1 November 2001 ISBN O 580 38583 3 I N T E R NAT I O NA L STANDARD ISOJIEC 7942-1 Second edition 1994-1 1
8、-01 Information technology - Computer graphics and image processing - Graphical Kernel System (GKS) - Part 1: Functional description Technologies de linformation - Infographie et traitement dimage - Systme graphique GKS - Partie I: Description fonctionnelle Reference number ISO/IEC 7942-1 :I 994(E)
9、ISO/IEC 7942-1: 1994(E) Contents . Foreword VIU Introduction ix 1 Scope . 1 2 Normative references 2 3 Definitions . 3 4 Conformance . 9 4.1 Specification 9 4.2 Registration . 9 5 Concepts 10 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5 . 5.10 5.11 5.12 5.13 5.14 Pic turcs 10 Output primitive classes and attri
10、butes 10 Workstations . 10 Coordinate systems and transformations . 14 Logical input devices . 14 Picture part store 14 State lists . 14 Description tables .4 Routing to the backdrop 15 Segments . 15 Compatibility with IS0 7942:1985 . 15 Metafiles and archives . 14 Audit trail 15 Summary . 15 6 The
11、Graphical Kernel System . 17 6.1 6.2 4.3 6.4 6.5 6.6 6.7 Initialization 17 Graphical output 17 6.2.1 Output primitive classes 17 6.2.2 Output primitive attributes . 17 Normalization transformations 19 Picture part store 20 6.41 Picture part creation . 20 4.4.2 Picture part functions . 20 6.4.3 Addin
12、g picture parts 20 6.4.4 Picture part archiving . 20 The NDC picture . 20 6.5.1 Introduction . 20 6.5.2 NDC picture operations . 21 6.5.3 NDC meiafiles . 21 Selection criterion 21 Graphical input 22 6.7.1 Introduction to logical input devices . 22 6.7.2 6.7.3 6.7.4 Logical input device model . 23 Op
13、erating modes of logical input devices . 24 Input queue and current event report . 25 ii ISOIIEC 7942-1:1994(E) 6.8 Inquiry functions 26 6.9 Error handling . 26 Special interfaces between GKS and the application program . 26 6.11 Backdrop . 26 Audit and playback 27 Workstation dependent control 28 6
14、.10 6.12 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 Introduction . 28 Workstation characteristics . 28 Selecting a workstation 29 Selection criteria 29 Viewing . 30 Workstation transformations . 30 Output primitives . 31 Colour . 32 Setting representations . 33 Removing a backdro
15、p 34 Visual effect state 34 Realized metafile . 34 Logical input devices . 34 7.13.1 Introduction . 34 7.13.2 Initialization of logical input devices 35 7.13.3 Definition of logical and composite input devices 35 Sending messages to a workstation . 35 8 Output primitives 36 8.1 Introduction . 36 8.2
16、 Curve output primitives . 36 8.2.1 Curve primitives 36 8.2.2 Curve attributes 37 Marker output primitives . 37 Area output primitives . 38 8.4.1 Area primitives 38 8.4.2 Definition of interior 38 8.4.3 Area attributes 38 Character output primitives . 40 8.5.1 Introduction . 40 8.5.2 Glyph specifica
17、tion 41 8.5.3 Glyph size 42 8.5.4 Text extent . 42 Text skewing 43 8.5.5 8.5.6 Text alignment . 44 8.5.7 Text orientation 46 8.5.8 Transformed text 47 8.5.9 Precision 47 8.5.10 Estimate of text extent . 48 Image output primitives . 48 Design output primitives 49 8.7.1 Introduction . 49 8.7.2 Stencil
18、s . 50 8.7.3 Stencil attributes 52 8.7.4 Stencil composition . 53 8.7.5 Tiling store . 57 8.7.6 Stencil and tiling functions 59 8.3 8.4 8.5 8.6 8.7 iii ISO/IEC 7942-1: 1994(E) 8.8 9.1 Introduction . 60 9.2 Measures of each logical input device class 60 9.3 Transformation of LOCATOR and STROKE input
19、61 9.3.1 9.3.2 Transformation of STROKE input 63 Prompt and echo types . 63 9.4.1 LOCATOR prompt and echo types . 63 9.4.2 STROKE prompt and echo types 64 9.4.3 VALUATOR prompt and echo types 64 9.4.4 CHOICE prompt and echo types . 65 9.4.5 PICK prompt and echo types . 65 9.4.6 STRING prompt and ech
20、o types . 66 Segments and workstation activation 67 10.1 Introduction . 67 10.2 Selection criteria 67 10.3 Segment state list . 68 10.4 Workstation activation . 68 10.5 Segment creation . 68 Generalized drawing primitive 59 Logical input device classes 60 9 Transformation of LOCATOR input . 61 9.4 1
21、0 10.6 Segment manipulation . 68 10.7 Segment attributes . 69 10.8 Segment storage . 69 10.9 Clear workstation . 69 11 Data types . 70 11.1.1 Notational conventions 70 11.1.2 Basic types . 72 Data types for output attributes . 75 11.1 Data type definitions 70 11.1.3 Data types for GKS control . 73 1
22、1.1.4 Data types for output primitives 73 11.1.5 11.1.6 Data types for transformations 78 11.1.7 Data types for NDC picture . 79 11.1.8 Data types for metafiles . 79 11.1.9 Data types for picture parts and archives 79 11.1.10 11.1.11 Data types for segments . 80 11.1.12 Data types for input . 81 11.
23、1.13 11.1.14 Data types for inquiry functions 83 11.1.15 Data types for operating state 83 11.1.16 Data types for font and glyph functions 84 11.1.17 Data types for audit trails . 84 11.1.18 Data types for selection criteria . 84 11.1.19 Data types for paths, tilings and stencils . 85 Data type defi
24、nitions for state lists and description tables . 87 11.2.1 Introduction . 87 11.2.2 Operating state list (OSL) 87 11.2.3 GKS description table (GDT) 87 11.2.4 GKS state list (GSL) 87 11.2.5 11.2.6 Data types for utility functions 80 Data types for workstation control 82 11.2 Workstation state list (
25、WSL) . 88 Workstation description table (WDT) . 88 iv ISO/IEC 7942-1:1994(E) 11.2.7 Error state list (ESL) 90 11.2.8 Segment state list (SSL) . 90 11.2.9 Stencil state list (STSL) . 90 Initial values of state lists and description tables 90 11.3.1 Operating state list . 90 11.3.2 GKS description tab
26、le 90 11.3.3 GKS state list . 90 11.3.4 Workstation state list . 92 11.3.5 Generic workstation description table . 92 11.3.6 Error state list . 92 11.3.7 Segment state list . 92 11.3.8 Stencil state list 92 Workstation independent functions . 93 12.1 Control functions . 93 12.2 Output functions 94 1
27、2.3 Design output functions . 95 12.4 Output attributes 97 12.5 Normalization transformation functions 98 12.6 NDC picture functions . 99 12.7 Metafile functions 100 12.8 Picture part store functions 1m1 12.9 Input functions . 103 12.10 Font and glyph functions . 104 Audit and playback functions 104
28、 12.12 Inquiry functions 105 12.13 Utility functions . 107 12.14 Utility functions for output primitives . 107 13 Workstation functions . 109 13.1 Control functions . 109 13.2 Inquiry functions 112 13.3 Retrieval functions . 114 13.4 Viewing utility functions . 115 13.5 Colour utility functions 115
29、Segment and workstation activation functions 116 14.1 Segment functions . 116 Workstation activation functions . 118 14.3 Utility functions . 119 11.3 12 12.11 14 14.2 Annexes A B C D E F Function and data type list . 120 A.l Functions alphabetic 120 Functions order of appearance . 122 Data types al
30、phabetic . 126 Error list 128 Function error list 128 Language binding considerations 140 D.l General 146 D.2 Global differences . 146 Workstation dependent differences . 146 Colour models . 149 Bibliography . 150 A.2 A.3 B.l B.2 Error list ordered by error number . 138 Allowable differences . 146 D
31、.3 V ISO/IEC 7942-1:1994(E) G An approach u compatibility with IS0 7942: 1985 . 151 G.1 Introduction . 151 (3.2 Format . 151 G.2.1 Compatibility aspects . 151 G.2.2 Language binding 151 Notation used in this annex . 151 G.3 Data structures . 151 G.3.1 Introduction . 151 G.3.2 Compatibility data type
32、s 152 G . 3.3 Compatibility operating state list (COSL) . 152 G.3.4 Compatibility GKS state list (CGSL) 152 G.3.5 Compatibility workstation state list (CWSL) 152 G.3.6 Compatibility segment state list (CSSL) . 153 G.4 Control functions . 153 G.4.1 OPEN GKS 153 G.4.2 OPEN WORKSTATION 153 G.43 CLOSE W
33、ORKSTATION 154 G.4.4 ACTIVATE WORKSTATION . 154 G.4.5 DEACTIVATE WORKSTATION . 155 G.4.6 CLEAR WORKSTATION 155 G.4.7 Deferral states 155 G.5 Output and attribute functions . 156 G.6 Transformation functions 156 G.6.1 SET VIEWPORT 156 G.2.3 G.6.2 SET WINDOW 157 G.6.3 SELECT NORMALIZATION TRANSFORMATI
34、ON 157 Workstation transformation functions . 157 G.8 Segment functions . 157 (3.8.1 Introduction . 157 G.8.2 CREATE SEGMENT 157 G.8.3 DELETE SEGMENT FROM WORKSTATION 157 G.8.4 ASSOCIATE SEGMENT WITH WORKSTATION158 G.8.5 COPY SEGMENT TO WORKSTATION 158 (3.8.6 INSERT SEGMENT . 158 G.8.7 Segment attri
35、butes . 158 G.9 Input functions . 158 G.7 G.9.1 Introduction . 158 G.9.2 Simultaneous events 159 G . 9.3 Pick input . 160 G.10 GKSM . 160 G.lO.l READ ITEM FROM GKSM . 160 G.10.2 GET ITEM FROM GKSM 160 G.10.3 INTERPRET ITEM . 160 G.10.4 WRITE ITEM TO GKSM . 161 G.11 Inquiry functions 161 G.11.1 Inqui
36、ry functions for operating state value 161 G.11.2 Inquiry functions for GKS description table . 161 G.11.3 Inquiry functions for GKS state list . 161 (3.11.4 Inquiry functions for workstation state list 161 G.11.5 Inquiry functions for workstation description table . 161 vi ISO/IEC 7942-1:1994(E) G.
37、11.6 Inquiry functions for segment state list . 162 (3.11.7 Pixel inquiries 162 Inquiry functions for GKS error state list 162 (3.12 Utility functions . 162 G.13 Error handling . 162 Matching error numbers 162 Using the utility function . 162 G.14 Conclusions . 163 ISO/IEC 11072: 1992 (informative)
38、164 H.l Introduction . 164 H.2 Environments 164 H.4 External interfaces . 164 H.6 Compositions 164 H.7 Collections 164 H.8 Clipping . 164 G.11.8 G.13.1 G.13.2 H Compatibility with the Computer Graphics Reference Model H.3 Fan-out and fan-in . 164 H.5 Processing elements . 164 vii ISO/IEC 7942-1:1994
39、(E) Foreword IS0 (the International Organization for Standardization) and IEC (the International Electrotechnical Commis- sion) form the specialized system for worldwide standardization. National bodies that are members of IS0 or IEC participate in the development of International Standards through
40、technical committees established by the respective organization to 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 ta
41、ke part in the work. In the field of information technology, IS0 and IEC have established a joint technical committee, ISOfiEC JTCl. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as International Standard requires app
42、roval by at least 75% of the national bodies cast- ing a vote. International Standard ISO/IEC 7942-1 was prepared by Joint Technical Committee ISODEC JTC1, Informa- tion technology, Sub-committee 24, Computer graphics and image processing. This second edition cancels and replaces the first edition (
43、IS0 7942:1985), which has been technically revised. ISO/IEC 7942 consists of the following parts, under the general title Information technology - Computer graphics and image processing - Graphical Kernel System (GKS): Part 1 : Functional description Part 2: NDC metafile Part 3: Audit trail Part 4:
44、Picture part archive Annexes A and B form an integral part of this part of ISO/IEC 7942. Annexes C, D, E, F, G, and H are for information only. . VI11 ISO/IEC 7942-1:1994(E) Introduction The Graphical Kernel System (GKS) provides a set of functions for computer graphics programming that can be used
45、by a range of applications. The main motivations for standardization are to improve portability of pro- grams and to define a basic methodology. Portability is achieved by providing all the capabilities necessary in a device independent way. The following principles are used in specifying GKS: a) De
46、sign: the three goals are consistency of approach, compatibility with related standards and orthogonal functionality where possible. b) Functionality: the goals are completeness with the minimal set of functions. Organization of functions should be such as to achieve compact programs. Richness shoul
47、d be provided by utilities and toolkits on top of GKS rather than non-standard extensions to GKS. c) Clarity: the underlying concepts should be easily understood, especially by the application programmer. To achieve this, GKS is defined using a small set of functions with precise specification of th
48、e data struc- tures that define the state of GKS and the effect that functions have on this state. d) Error handling: all errors caused by incorrect function invocations or internal failures are logged with the application having control over the action taken. e) Separation of device dependent funct
49、ionality: in GKS there is a clear separation between the functional- ity that is device dependent and device independent. GKS has the concept of a workstation which deals with all device dependent functions. f) Implementation: GKS should be realizable in a wide range of host languages. The support GKS requires from the operating system should not be excessive. GKS should be efficient to implement on commonly available hardware and it should be easy to produce a robust product. This International Standard (known informally as “GKS-94“) has a strong relationship to the principles and functio
