Overview
ISO/IEC 7942-1:1994 - "Information technology - Computer graphics and image processing - Graphical Kernel System (GKS) - Part 1: Functional description" is the second edition (1994) of the GKS functional description. It cancels and replaces the 1985 edition and specifies a portable set of 2D graphics functions (the Graphical Kernel System) for producing, storing, modifying and interacting with two‑dimensional pictures on both vector and raster devices, in monochrome or colour. This part defines the functional model, service classes and expected behaviour of a conforming GKS implementation.
Key topics and technical requirements
- Output primitives and attributes: standardized primitive classes (curves, markers, areas, characters, images, design primitives, generalized drawing) and their attributes (line, fill, text, colour, etc.).
- Coordinate systems & normalization transformations: device‑independent coordinate models and transformations to map world coordinates to normalized device coordinates (NDC) and to physical workstations.
- Workstations: workstation classes, characteristics, selection criteria, activation, viewing and workstation‑dependent controls (including colour handling and visual effects).
- Logical input devices: device classes and models for LOCATOR, STROKE, VALUATOR, CHOICE, PICK, STRING, plus prompt/echo behaviour, input queues and event reporting.
- Picture storage and segments: picture part store, segments, dynamic modification, archiving and realized metafiles for replay.
- Metafiles, archives & audit/playback: standardized metafile structures and mechanisms for recording and replaying graphical sessions.
- Design primitives: stencils, tilings and related attributes for complex fills and patterns.
- Conformance, registration & error handling: rules for conformance testing, function/data type registration and error reporting.
- Data types & inquiry functions: well‑defined data types for primitives, attributes, transformations, and a comprehensive set of inquiry utilities.
Applications and who uses it
ISO/IEC 7942-1 is intended for implementers and integrators who need a portable, standardized 2D graphics API, including:
- Graphics library and driver developers implementing GKS on vector or raster hardware
- CAD/CAM, plotting and scientific visualization software vendors
- Engineering, GIS and instrumentation display systems requiring device‑independent drawing and input handling
- Embedded systems and printers that produce standardized 2D output
- Standards bodies and archivists dealing with metafile interoperability and audit/playback
Related standards
- ISO/IEC 7942 series (other parts specify language bindings, metafile formats and additional technical detail)
- Other graphics standards and windowing/printing specifications (for integration and device mapping)
ISO/IEC 7942-1:1994 remains a foundational reference for GKS, offering a rigorous functional description for creating interoperable, workstation‑independent 2D graphics systems.