Abstract: A method and apparatus for distinguishing reference values from non-reference values in a runtime environment is described. A set of volatile registers and a set of non-volatile registers are statically determined. The set of volatile registers is partitioned into reference and non-reference register partitions statically. The set of non-volatile registers is partitioned into reference and non-reference partitions dynamically.

Abstract: A deferred graphics pipeline processor comprising a texture unit and a texture memory associated with the texture unit. The texture unit applies texture maps stored in the texture memory, to pixel fragments. The textures are MIP-mapped and comprise a series of texture maps at different levels of detail, each map representing the appearance of the texture at a given distance from an eye point. The texture unit performs tri-linear interpolation from the texture maps to produce a texture value for a given pixel fragment that approximates the correct level of detail. The texture memory has texture data stored and accessed in a manner which reduces memory access conflicts and thus improves throughput of said texture unit.

Abstract: A method and system for selectively permitting address values to pass between two buses. Portions of the address values are used to select data in a mask register. The determination of whether to pass the address value is made on the basis of the mask register value ultimately selected.

Abstract: Image data resulting from a digitizing process, for display of an image on a digital display device, is monitored by selectively storing the data in diagnostic registers. This data is analyzed, and used to track the performance of the digitizer on the basis of various operating parameters such as inter-channel balance, intra-channel balance, contrast, brightness, white point, image centering and data clock. A communication channel from the image source provides information regarding the content of the image data being monitored. Based upon the indicated content provided by the image source, the system automatically compensates for any detected error, to thereby maintain optimum performance.

Abstract: A data shifting capability that permits sorting the data in addition to searching for obtaining real-time performance in color, with high quality imagery through a simple search of a spacial database based on a rectangularly shaped search region or range search. A sorting Magnitude Comparison Content Addressable Memory (SMCCAM) performs a range search, introducing a conservative approximation of the idea Occluding Region, and provides a MCCAM wherein the data words stored in the fields are shifted to corresponding fields in an adjacent word, based on the magnitude comparisons. The 3D graphics method stores the parameters of a polygon span in a spatial database and a query operation is performed on the database to determine which of those spans, or portions of spans, are visible, and applies a rule for comparing a new span portion to an old span portion on a subspan-by-subspan basis, thereby providing additional polygon edge information within a raster line, providing anti-aliasing.

Abstract: A system and method for interfacing index based and iterator based file management routines. In general, the disclosed system maintains an iterator cache having multiple iterators. Each active iterator is associated with a most recently used directory entry. Upon receiving an index based request, the iterator closest to the index based request is identified. If the index based request is closer to the top of the directory than it is to the closest active iterator, the directory entries are sequentially examined beginning at the top of the directory with the first entry. Otherwise, the system determines whether the index based request is located above or below the closest iterator. If the index based request is above the closest iterator, the system steps backward beginning with the directory entry associated with the closest iterator until the directory entry associated with the index based request is located.

Abstract: A hot-plugging capability for video devices is achieved by shifting the responsibility for recognizing changes in the configuration of a display environment from a computer's operating system to a device manager. When an input/output device is added to or removed from the computer system, an interrupt signal informs a device manager of the fact that a change in configuration has occurred. In response thereto, the device manager determines whether the changed component relates to the computer's display function. If so, the device manager makes a call to the computer's display manager, to inform it of the fact that the display configuration has changed. In response to this call, the display manager reconfigures the display space for the computer system and notifies clients as appropriate, to accommodate display features associated with the added component. With this change in the configuration of the display space, the added component becomes immediately available for use.

Abstract: Aspects for utilizing functionality of an application program interface (API) of a computer system through script access to the API are described. A method aspect includes receiving a script of one or more desired events for manipulating a file, the file having a format, identifying whether a compatible format for the file is known by the API and executing the script on the file by the API when a compatible format is known.

Abstract: A high quality stereophonic sound enclosure system high resolution intended for computer visual display monitors employing cathode ray tubes (CRTs) having a vertical aperture grill, and methods for construction of same. The aperture grill has a natural frequency centered within the musical scale. The stereo speaker system comprises a ported speaker enclosure within which are mounted two conventional cone speaker assemblies. A stereo audio amplifier and control unit for controlling the audio signals delivered to the speakers is mounted within the speaker enclosure. The speaker enclosure is internally mounted within the monitor with a minimum number of attachment members incorporating vibration isolation material to remove vibration components near the natural frequency of the aperture grill. The speaker enclosure is internally reinforced to reduce structural deformations which contribute to airborne transmitted vibration within the monitor housing when the speaker system is operating.

Abstract: In a printing system having multiple printers, separate print spoolers are launched for each different printer to which a print job is directed. When a document file is sent to a print manager and a spool file is created, the spool file is moved to the specific spooler associated with the printer on which the document is to be printed. Each spooler communicates directly with its associated printer, with respect to all jobs designated for that printer. The various spoolers operate in parallel, and independently of one another. As a result, if one printer is unable to complete a job, the print jobs destined for other printers are not affected, and can be completed.

Abstract: A method and system for matching color displayed by source and destination display devices and particularly for providing color matching between a computer monitor and an ink printer. The technique of the present invention initially determines the combination and color value ratios of single destination color components that will cause the destination device to display a color that essentially matches each of fully saturated single and dual colors of a source display device. These combinations of single destination color components and their corresponding color value ratios determine the best available blends of destination device color components for printing source device colors. A color matching algorithm is employed to derive the color value ratios—one for each of the single destination color components.

Abstract: Aspects for ensuring the integrity of a cache file utilized by an application program interface of a computer system are provided. A method aspect includes forming a checksum with a modification date value of each of a plurality of files, storing the checksum in the cache file, and utilizing the checksum to validate data in the cache file.

Abstract: A clipboard manager which employs preemptive scheduling for access to contents of a clipboard region of memory in a computer remains backwardly compatible with application programs designed for cooperative scheduling, through the use of a locking mechanism. When an application which is designed for use with a preemptive scheduling interface desires access to the clipboard, it requests a key from a clipboard manager. As long as the application possesses the key, no other application can gain access to the clipboard. When an application which is designed for cooperative scheduling becomes the foreground program on the computer, the clipboard manager retains the key for itself. As long as this application is active, the clipboard manager prevents any other application running in the background from gaining access to the clipboard, and thereby avoids potential conflicts.

Abstract: Objects in an image are rendered in a manner which dynamically avoids the rendering of obscured objects. Data pertaining to one object is stored in a designated memory location, such as a cache memory. Data for a subsequent object is compared with the stored data, and the area of intersection between the two objects is determined. This area of intersection is subtracted from the first object, and the data for the second object is added to the memory. As the memory is filled, the data for the oldest object is removed and the object is rendered. After all objects in the list have been processed in this manner, those which remain in the memory are also rendered, and removed from the memory. At each step of the process, the portions of an object which are obscured by later-generated objects are eliminated, and thereby unnecessary rendering of obscured objects is avoided.

Abstract: Three-dimensional computer graphics systems and methods and more particularly to structure and method for a three-dimensional graphics processor and having other enhanced graphics processing features. In one embodiment the graphics processor is a Deferred Shading Graphics Processor (DSGP) comprising an AGP interface, a command fetch & decode (2000), a geometry unit (3000), a mode extraction (4000) and polygon memory (5000), a sort unit (6000) and sort memory (7000), a setup unit (8000), a cull unit (9000), a mode injection (10000), a fragment unit (11000), a texture (12000) and texture memory (13000) a phong shading (14000), a pixel unit (15000), a backend unit (1600) coupled to a frame buffer (17000). Other embodiments need not include all of these functional units, and the structures and methods of these units are applicable to other computational processes and systems as well as deferred and non-deferred shading graphical processors.

Abstract: A printer driver, for example a QuickDraw printer driver, keeps track of changes in a drawing environment (specified by a GrafPort) by saving State records. Rather than filling up the State with the contents of each pattern and clip region, references to each of these members are stored in the State. This referencing allows each component of a State to be saved separately while still allowing the State to be reproduced precisely when it is time to draw. Referencing can greatly reduce disk accesses and file size, thereby accelerating printing. Referencing also allows significant time to be saved during state comparison. Whereas previous drivers have required a State to GrafPort comparison at translation (drawing) time, in the present method, each reference in the current state may be compared with references from the previous state to see which fields have changed. Comparing references, which may be stored in four bytes, is much faster than comparing large patterns and regions.

Abstract: A user interface and methods for using a user interface for controlling processing of time-based media files. In one exemplary method, a graphical representation of a time line for a time-based media is displayed along with a graphical representation of a current time along the graphical representation of the time line. A start graphical indicator and a stop graphical indicator is also displayed along the graphical representation of the time line. A portion of the time-based media may be selected for presentation by dragging or positioning at least one of the start graphical indicator and the stop graphical indicator along the graphical representation of the time line. In another aspect of the invention, an exemplary method allows for the adaptive control of a portion of the interface which indicates time relating to a time-based media. An input speed is determined where this input is to change the portion and the rate at which the change to this portion occurs is dependent upon the input speed.