1、BRITISH STANDARD BS ISO 8805:1988 Information processing systems Computer graphics Graphical Kernel System for Three Dimensions (GKS-3D) functional description ICS 35.140 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS ISO/IEC 8805:1988 This British Standard, having been pre
2、pared under the direction of the DISC Board, was published under the authority of the Standards Policy and Strategy Committee on 2 November 2001 BSI 2 November 2001 ISBN 0 580 38579 5 National foreword This British Standard reproduces verbatim ISO 8805:1988 and implements it as the UK national stand
3、ard. It supersedes BS EN 28805:1992 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee IST/31, Computer Graphics and Image Processing, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to it
4、s 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 Index”, or by using the “Find” facility of the BSI St
5、andards 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 itself confer immunity from legal obligations. aid enquire
6、rs to understand the text; present to the responsible international/European 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. Summary of pages This docume
7、nt comprises a front cover, an inside front cover, an ISO title page, pages ii to vii, a blank page, pages 1 to 379 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsINTERNATIONAL
8、 STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXJjYHAPOflHAfl OPTAHM3AMfl fl0 CTAHAPTM3AQMM Information processing Systems - Computer graphics - Graphical Kerne1 System for Three Dimensions (GKS-3D) functional description S yst b) storage and
9、manipulation of graphical data; c) input of graphically related data. The main reasons for introducing this International Standard for Computer graphics is: d) to allow application programs involving graphics to be easily portable between different ins- tallations; e) to aid the understanding and us
10、e of graphics methods by application programmers; f) to serve manufacturers of graphics equipment as a guideline in providing useful combinations of graphics capabilities in a device. In Order to resch these main objectives, the GKS-3D design was based on the following require- ments: g) GKS-3D shou
11、ld include all the capabilities that are essential for the whole spectrum of graph- ics, from simple passive output to highly interactive applications. h) The whole range of graphics devices, including vector and raster devices, microfflrn recorders, storage tube displays, refresh displays and colou
12、r displays should be controllable by GKS-3D in a uniform way. i) GKS-3D should provide all the capabilities required by a majority of applications. These requirements were used to formulate a number of principles that were used to judge specific design alternatives. Thus it was possible to contribut
13、e to the overall design goals while focussing on certain aspects. Five design aspects were identmed, each having a group of principles Isos8os:1!M8(E) Introduction j) Design goals: The following principles should not be violated by any technical design: 1) consistency: the mandatory requirements of
14、GKS-3D should not be mutually contradic- 2) compatibility: other Standards or commonly accepted rules of practice should not be violated; 3) orthogonality: the functions or modules of GKS-3D should be independent of each other, or the dependency should be structured and well defined. k) Functional c
15、apabilities: The following principles were used to define the extent of GKS-3D: 1) completeness: all functions that a majority of applications want to use on a given level of functionality should be included; 2) minimality: functions that are unnecessary for applications of a given level of function
16、ality should not be provided; 3) compactness: an application should be able to achieve a desired result by a set of func- tions and Parameters that is as small as possible; 4) richness: a rich set of functions offers an extensive range of facilities that stretches beyond the basic functions and incl
17、udes higher Order capabilities. It is obvious that there is a trade off between the principles in this group. Therefore, the functions of GKS-3D are organized in nine levels. An implementation of GKS-3D provides precisely the functions of one of these levels. While the lowest level contains only a m
18、inimal set of functions, higher levels are allowed to extend beyond the basic needs towards greater richness. 1) User interface design: The following principles were used to define the User interface design: 1) User friendliness: GKS-3D should allow the design of a desirable User interface; 2) clari
19、ty: the concepts and functional capabilities of GKS-3D should be easily understand- able, especially by the application programmer; 3) error handling: failure of System functions or modules, caused by errors of the System itself or by the application program, should be treated in such a way that the
20、 error reaction is clearly understandable and informative to the application programmer and that the impact on the System and the application program is as small as possible. Clarity and Sound error handling arc essential Parts of User friendliness. Error handling is an integral part of GKS-3D. To a
21、id clarity, the System, and its state tan be presented to the User in an easily comprehensible manner. Clarity applies not only to the System design but also to the System description. To this end, the GKS-3D specmcation is divided into a general description, a description of the underlying logi- ca
22、l data structures representmg the state sf the System, and a description of the functions and their effects on these data structures. m) Graphits devices: The following principles are associated with the range of graphics devices that tan be addressed by GKS-3D: 1) device independence: GKS-3D functi
23、ons should be designed to allow an application pro- gram, using these functions, to address facilities of quite different graphics output and input devices without modification of the program structure; 2) device richness: the full capabilities of a wide range of different graphics output and input
24、devices should be accessible from the functions of GKS-3D. These principles led to a fundamental concept underlying the GKS-3D architecture: the concept of multiple mdependent graphical workstations connected to and driven by GKS-3D. The appli- cation piogram tan inquire-the capabilities of every workstation. The GKS-3D design includes escape functions that arc easily identtiable within an application program and tan be used to access special facilities of a particular device. 2
