Abstract: A programming interface is provided in a computer graphics system which allows plural hardware display adapters to be upgraded and enhanced without correspondingly upgrading and rewriting display specific device driver code for each separate program application using the graphics system. A resource library with a standard programming interface, but specific to each display adapter is included, as well as display driver code for each adapter. Functions necessary to service the graphics model embodied in the program application are configured as device driver models and also are included within the interface of the present invention. Initially, the functions provided in the resource library are dynamically bound to expose the functionality of the desired display adapter. A second level of dynamic binding is implemented to bind the program application with the display specific code and graphic models being utilized.

Abstract: A method is provided for shifting focus between multiple program applications in a virtual terminal environment such that next successive application will always become visible and capable of interaction with a user upon a single hot key operation. In the system of the present invention multiple applications are provided, at lease one of which is capable of writing directly onto multiple hardware display devices. Also, a plurality of virtual terminals are opened, each being associated with a particular program application and corresponding to a hardware display device. All but one of the virtual terminals associated with a single application are designated as "non participating" in any hot keying operation. Therefore, upon implementation of a hot key operation these non participating virtual terminals are ignored and the next participating virtual terminal will be activated.

Abstract: The system and method of this invention processes a data stream based on the structure of a font file which can be varied by a user or application of the processing system. The font file not only contains the pel patterns for a range of graphical symbols, but it also contains the rules for, interpreting a data stream having a particular syntax. The rules for interpreting a data stream are referred to as the processing model for the data stream.The structure of the font file contains an index array to the range of graphical symbols. Each byte in the data stream is used to generate an index into the index array. In each element of the index array there is a value and control bits. The control bits indicate whether the value is an offset to a graphical symbol or whether the value is a modifier. If the value is a modifier, it is used to increment the next sequential data byte in the data stream through the range of graphical symbols.

Abstract: The system and method of this invention processes a data stream based on the structure of a font file which can be varied by a user or application of the processing system. The font file not only contains the pel patterns for a range of graphical symbols, but it also contains the rules for interpreting a data stream having a particular syntax. The rules for interpreting a data stream are referred to as the processing model for the data stream. The structure of the font file contains an index array to the range of graphical symbols. Each byte in the data stream is used to generate an index into the index array. In each element of the index array there is a value and control bits. The control bits indicate whether the value is an offset to a graphical symbol or whether the value is a modifier. If the value is a modifier, it is used to increment the next sequential data byte in the data stream through the range of graphical symbols.