Fast graphics control system capable of simultaneously storing and

Abstract

A host computer, a graphics processor which receives and executes commands generated by the host computer, a display memory for storing display data, and a display device for displaying the display data are provided. A graphics context is also provided in which the parameters of a current image are stored. A processing unit for receiving and executing the graphics commands issued by the host computer and for converting the parameters stored in the graphics context into the display data, and a drawing unit for storing the display data in the display memory are also provided. Furthermore, a shared memory is provided which is directly accessible to the host computer so that it can write the parameters of a next graphics command into the shared memory while the graphics processor is executing a current command. The shared memory is also directly accessible to the graphics processor so that it can receive the parameters of the next graphics command to be executed directly from the shared memory. In a preferred embodiment, transfers of the graphics parameters between the graphics context and the shared memory are accomplished by employing a bit-block transfer method and a mask register stored in the graphics context.