A figure editing apparatus for editing figure sets each comprising a set of a plurality of basic figures includes a first memory for storing, in correlated form, each figure set and the plurality of basic figures constituting the figure set, a second memory for storing, in correlated form, each figure set and an area corresponding to the figure set, a third memory for storing, in correlated form, the basic figures and areas corresponding to the basic figures, and an adding/deleting unit for designating an area corresponding to a figure set or basic figure, thereby to add a basic figure to or delete the basic figure from the first memory. The editing of figure sets, each of which comprises a set of a plurality of basic figures, and particularly the editing of a graphical program, is simplified.

A graphics system utilizes the graphics standardization specification PEX for providing high-speed drawing when a client and a server locally operate on the same machine and allow an application to change structure and graphics attributes defined by another application without being aware of the distinction between local and remote cases.

A multi-processor graphics system including a general purpose system control processor for setting up the workstation environment and data traversal structures based upon an application model language description. Workload balancing and interprocessor communication is managed by defining a general purpose interface between the general purpose processor and special purpose graphics control processor. The system control processor accepts application program information in a standard form, such as a hierarchical graphics language definition, then converts it into generalized interface control blocks for communication to the graphics control processor. Graphics control processor is signalled by an interrupt from the system control processor to begin the traversal process. The graphics control processor can then access the standard control blocks contained in system memory and perform the traversal necessary to generate the requested graphics image. Generalized control blocks allow rapid adaptation to program changes and efficient communication between the general purpose and specialized processors.

The method of rendering an X Windows server system running on a server and at least one host computer terminal secure including the steps of allowing users to view only resources of the X Windows server system the use of which has been specifically authorized to that user, and allowing users to manipulate only resources of the X Windows server system the use of which has been specifically authorized to that user.

An interactive image editor. Editing commands are interactively imputted to a computer by a user to form an image transformation function. The commands define how to alter the pixels of the image and the portions of the image to alter. The editor parses the commands and generates a program for performing the image transformation. The program is then executed, either by interpreting it or by first compiling it on-the-fly. In either case, each affected pixel of the image is transformed in accordance with the command statements.