BS ISO/IEC 9636-1:1991

Foreword
Introduction
1 Scope
1.1 Relationship of CGI to a computing environment
1.2 Position of CGI in a managed environment
2 Normative references
3 Definitions and abbreviations
3.1 Organization of the definitions
3.2 Definitions
3.3 Abbreviations
4 Reference models
4.1 Introduction
4.2 Model for CGI client/target relationships
4.2.1 CGI configurations diagram
4.2.2 Types of clients
4.2.3 Types of targets
4.3 Example configurations
4.3.1 CGI Virtual Devices as GKS workstations
4.3.2 CGM interpretation using CGI
4.3.3 CGI Virtual Devices as 3D workstations
4.3.4 Input/output workstations as combinations of
        CGI Virtual Devices
4.4 Relationship to other standards
4.4.1 Introduction
4.4.2 CGI data encodings standards
4.4.3 CGI language bindings standards
4.4.4 Relation to GKS (ISO 7942 1985)
4.4.5 Relation to GKS-3D (ISO 8805 1989) and PHIGS
        (ISO/IEC 9592 1989)
4.4.6 Relation to CGM (ISO 8632 1987)
4.4.7 Relation to Procedures for Registration of
        Graphical Items
5 Concepts
5.1 Introduction
5.2 Global CGI concepts
5.2.1 CGI Graphic Object Pipeline
5.2.2 CGI state model
5.2.3 Description tables
5.2.4 State lists
5.2.5 Static and dynamic state lists
5.2.6 The structure of description tables and state
        lists
5.2.7 The principles of inquiry
5.2.8 Error philosophy
5.2.9 Method of describing functions
5.2.10 Data types employed
5.2.11 Formal grammar
5.3 Overview of ISO/IEC 9636-2: Control
5.4 Overview of ISO/IEC 9636-3: Output
5.5 Overview of ISO/IEC 9636-4: Segments
5.6 Overview of ISO/IEC 9636-5: Input and echoing
5.7 Overview of ISO/IEC 9636-6: Raster
6 Profiles
6.1 Profile definition
6.1.1 Constituency Profile registration
6.2 Foundation Profiles
6.3 Constituency Profiles
6.3.1 GKS Constituency Profiles
6.3.2 CGM Constituency Profile
6.3.3 Advanced 1-Way Output Constituency Profile
6.4 Foundation Profile definition
6.4.1 2-WAY OUTPUT Foundation Profile
6.4.2 1-WAY OUTPUT Foundation Profile
6.4.3 INPUT Foundation Profile
6.5 GKS Profile definition
6.5.1 GKS OUTPUT-0 Profile
6.5.2 GKS OUTPUT-1 Profile
6.5.3 GKS INPUT-b Profile
6.5.4 GKS INPUT-c Profile
6.5.5 GKS OUTIN-0b Profile
6.5.6 GKS OUTIN-0c Profile
6.5.7 GKS OUTIN-1b Profile
6.5.8 GKS OUTIN-1c Profile
6.6 CGM Profile definition
6.6.1 BASIC CGM Profile
6.7 Other Constituency Profile definitions
6.7.1 ADVANCED 1-WAY OUTPUT Profile
7 Classification and designation
7.1 Implementation conformance
7.2 Client conformance
7.3 Extensions
7.4 Inquiry
7.5 Parsing
A Function identifiers
B Profile identifiers
C Guidelines for bindings and encodings
D Formal guidelines for definition of Constituency
        Profiles
E CGI in a distributed system model
F Typographic conventions

Establishes the conceptual model, functional capability, and minimum conformance requirements of the Computer Graphics Interface (CGI). It specifies design requirements for encodings of the CGI.

ISO/IEC9636 establishes the conceptual model, functional capability, and minimum conformance requirements of the Computer Graphics Interface (CGI). It specifies design requirements for encodings of the CGI. ISO/IEC9636 defines a set of CGI functions that is expected to satisfy the following needs of a majority of the computer graphics community: provide an interface standard for computer graphics software package implementors; provide an interface standard for computer graphics device manufacturers and suppliers; provide an inquiry and response mechanism for graphics device capabilities, characteristics, and states; provide a standard graphics escape mechanism to access non-standard graphics device capabilities; allow for future functional extension of the CGI. In addition to the CGI functionality, device classes, and Foundation and Constituency Profiles are defined. The device classes included in the CGI are output (OUTPUT), input (INPUT), and output/input (OUTIN). Profiles allow subsets of the CGI functions and features to be defined to suit particular well identified groups of users. There is also provision for Constituency Profiles to be registered after ISO/IEC9636 is published. The Computer Graphics Interface (CGI) is a standard functional and syntactical specification of the control and data exchange between device-independent graphics software and an implementation of a CGI Virtual Device. The syntax of the CGI, presented in ISO/IEC9636, is an encoding-independent and binding-independent specification. Any similarity of the examples or function specifications to a particular encoding technique or language is coincidental unless explicitly stated otherwise. The functions specified provide for the representation of a wide range of two-dimensional pictures and for control over their display on a wide range of graphics devices. The functions are split into groups that perform device and CGI session control, specify the data representations used, control the display of the picture, perform basic drawing actions, control the attributes of the basic drawing actions, acquire data from input devices, and provide access to non-standard device capabilities. This part of ISO/IEC9636 gives an overview of ISO/IEC9636, explains the relationship between its parts and their relation to other standards, describes a reference model for graphics systems, and defines certain Foundation and Constituency Profiles. ISO/IEC9636-2, ISO/IEC9636-3, ISO/IEC9636-4, ISO/IEC9636-5, and ISO/IEC9636-6 specify the CGI functions for different functional areas using an abstract notation. ISO/IEC9637 and ISO/IEC9638 define standard data stream encodings, procedural library bindings, and single entry point procedural bindings of the CGI. 1.1 Relationship of CGI to a computing environment ISO/IEC9636 describes graphical services provided by a Virtual Graphics Device. The model for description of these services is expressed in terms of graphical capabilities of a single instance of a hypothetical graphics device. In all but the simplest of computing environments, CGI functions alone will not be sufficient to provide complete control over a device. Additional functions, not included in ISO/IEC9636, will likely be needed. Examples of such functions include means to configure (sets of) physical devices to be accessed as CGI Virtual Devices; means to control a device capable of offering CGI-defined services as well as other, non-CGI-defined services, such as those implied by ISO2022 and ISO6429; means to differentiate among separate instances of CGI Virtual Devices in the same computing environment; means of defining or determining communication paths from CGI clients to CGI Virtual Devices. In some cases, other standards exist that describe the functions required. For example, various communications standards address the needs of the last point above. In other cases, no standards may exist, but the tasks indicated are outside the scope of ISO/IEC9636. 1.2 Position of CGI in a managed environment There exists a large and growing family of computer controlled display systems that have the ability to act as if they are multiple individual display devices. Resources, most notably the visible drawing surface resources, are coordinated by the display system so that multiple non-cooperating client programs can each access the services of a separate individual device while all are actually running in a single managed environment. The graphical capabilities of the CGI Virtual Device may suffice, in some instances, as the basis for implementing a complex, multiple-client display system. However, the complete needs of such a system are quite complex, include many non-graphical services, and (as current practice shows) are quite technology dependent. The CGI does not, therefore, purport to be a generally sufficient interface on which a managed display environment may be built. Rather, within a managed environment, the CGI will be one of the managed interfaces in a way not visible to the CGI client without recourse to services not part of ISO/IEC9636. The use of the CGI as a managed interface within a managed display environment is not limited to raster devices.