Abstract: The present invention provides a method and apparatus that permits the introduction of customized compositing techniques into an application by a developer. A Composite interface and a CompositeContext interface are defined. Custom compositing operations can be defined by implementing these interfaces. A Composite object provides a CompositeContext object that holds the state and performs the compositing work. Multiple CompositeContext objects can be created from one Composite object to maintain separate states in a multi-threaded environment. An object implementing the Composite interface can be set as rendering state on a graphics object that provides rendering methods. This allows arbitrary compositing rules to be used by a developer. In one implementation of the Composite and CompositeContext interfaces, an AlphaComposite class is defined.

Abstract: The invention provides a method and apparatus for customizing and substituting strokes provided by a standard API. In a preferred embodiment, a stroke interface that encapsulates stroking algorithms and interfaces for stroke calculation is provided by an API. The stroke interface is provided in the form of a class. The use of the stroke interface permits additional algorithms and interfaces to be provided as new classes. This allows developers to customize stroke characteristics and attributes. In a preferred embodiment, a basic stroke class contains standard stroke characteristics of a logical pen. These characteristics include line width, end cap shape, line join style, and dash attributes.

Abstract: Raw image data is separated from color image data such that image data can be operated on independent of a color model. Alternatively, image data can be associated with a color model and image processing operations can operate on the image data in terms of the color model. No color model is presupposed for a given image. When an image processing operation uses a color system, a color system can be selected in which the operation is performed and the source image will be converted. Different color systems can be associated with the same image data to process the image. Where it is not necessary to perform an image processing operation in a color system, the operation can access the image data independent of a color system. In an embodiment of the invention, a Tile object class is comprised of an array of Channel objects. A Channel object is associated with one or more storage bands of image data.

Abstract: The present invention provides a method and apparatus that permits the introduction of customized compositing techniques into an application by a developer. A Composite interface and a CompositeContext interface are defined. Custom compositing operations can be defined by implementing these interfaces. A Composite object provides a CompositeContext object that holds the state and performs the compositing work. Multiple CompositeContext objects can be created from one Composite object to maintain separate states in a multi-threaded environment. An object implementing the Composite interface can be set as rendering state on a graphics object that provides rendering methods. This allows arbitrary compositing rules to be used by a developer. In one implementation of the Composite and CompositeContext interfaces, an AlphaComposite class is defined.

Abstract: The system of the present invention provides for the synchronization of access devices connected through the system's memory management unit and is particularly useful in a multi-tasking computer system in which multiple processes access the same device. In the method and apparatus of the present invention, devices that are connected to the system through the MMU are controlled using the page fault mechanism of the MMU and the page fault handler in each segment. Addresses are allocated in the process address space for each process to provide for the addressing of the devices and device queues connected through the MMU, such that one device or one device queue is mapped into one segment of each process address space that will access the device. The "valid bits" associated with each page in a segment are turned on/off by the process or operating system in order to control the device.

Abstract: The system of the present invention provides for the flow control of commands to devices connected through the system's memory management unit and is particularly useful in a multi-tasking computer system in which multiple processes access the same device. In the method and apparatus of the present invention, devices that are connected to the system through the MMU are controlled using the page fault mechanism of the MMU and the page fault handler in each segment. Addresses are allocated in the process address space for each process to provide for the addressing of the devices and device queues connected through the MMU, such that one device or one device queue is mapped into one segment of each process address space that will access the device. The "valid bits" associated with each page in a segment are turned on/off by the process or operating system in order to control the device.