The DI-3000 implementation of the 1979 GSPC 'CORE' graphics standard

摘要

DI-3000 is a machine-independent system of FORTRAN-callable subroutines based on the 1979 'CORE' report of the Graphics Standards Planning Committee (GSPC) of ACM/SIGGRAPH.

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DI-3000 supports Output Level-3 (dynamic output), Input Level-2 (synchronous input), and Dimension Level-2 (3D) of the CORE. This includes the complete support of 2D and 3D primitives, full 3D viewing definitions, multiple concurrent display surfaces, Hershey text fonts, all logical input functions, and image transformations. The raster extensions defined in the 1979 CORE Report are also supported, including polygonal primitives, shaded or patterned polygons, and dynamic definition of color video lookup tables on raster devices.

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DI-3000 uses a network of several interconnected virtual graphics devices which communicate with each other via messages. These virtual devices may represent physical graphics devices, graphics metafiles, or device-independent display files for storing retained segments.

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The DI-3000 logical network may be implemented in various ways, depending on the architecture and operating system of the target computer system. The network concept is ideally suited to multi-tasking or distributed processing environments, where either the central memory of the host computer is limited or the target graphics devices have local intelligence. Using a logical network, the virtual graphics devices can execute concurrently for increased efficiency.

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All virtual devices have a distinct layer structure. This allows easy maintenance and extension of the system as the graphics standard evolves, without changes in the basic design. The layer structure also makes it easy to build new graphics device drivers.