Method and apparatus for displaying image data of a virtual desktop from one or more frame buffers onto a display screen

A computer system, including:

• a processor;
• a display device having a display screen;
• and
• a graphics unit coupled between the processor and the display device, wherein the graphics unit includes graphics memory that defines at least two frame buffers, at least one of the frame buffers holds a virtual desktop image that cannot be entirely displayed on the display screen, the graphics unit is configured to assert, to the display device, a first set of filtered display data being computed from a first subset of the display data in said at least one of the frame buffers and that is associated with a first portal of the virtual desktop image, wherein the first portal is configurable to correspond to any region of the virtual desktop image, and the processor and the graphics unit are configured to respond to at least one control signal during or after assertion of the first set of filtered display data to the display device, by asserting to the display device a second set of filtered display data being computed from a second subset of the display data in said at least one of the frame buffers and that is associated with either a second portal of the virtual desktop or a resized version of the first portal of the virtual desktop, wherein each of the second portal and the resized version of the first portal is configurable to correspond to any region of the virtual desktop image, and
• wherein the processor is configured to perform multi-display operations in which the processor independently generates multiple frames of display data for simultaneous display and asserts the frames to the graphics unit, and the graphics unit is configured to store the frames in the frame buffers and to assert display data determined by at least a subset of the display data in each of the frame buffers to the display device for simultaneous display.

A computer system, including:

• a processor;
• a display device having a display screen;
• and
• a graphics unit coupled between the processor and the display device,
• wherein the graphics unit includes graphics memory that defines at least two frame buffers, at least one of the frame buffers holds a virtual desktop image that cannot be entirely displayed on the display screen, the graphics unit is configured to assert, to the display device, a first set of filtered display data being computed from a first subset of the display data in said at least one of the frame buffers and that is associated with a first portal of the virtual desktop image, the processor and the graphics unit are configured to respond to at least one control signal during or after assertion of the first set of filtered display data to the display device, by asserting to the display device a second set of filtered display data being computed from a second subset of the display data in said at least one of the frame buffers and that is associated with a second portal of the virtual desktop at a predetermined location of said virtual desktop image, wherein the second portal is configurable to correspond to any region of the virtual desktop image, and wherein the processor is configured to perform multi-display operations in which the processor independently generates multiple frames of display data for simultaneous display and asserts the frames to the graphics unit, and the graphics unit is configured to store the frames in the frame buffers and to assert display data determined by at least a subset of the display data in each of the frame buffers to the display device for simultaneous display.

A graphics unit for use in a computer system, the computer system including a display device having a display screen and a processor configured to generate frames of display data, said graphics unit including:

• at least one input configured to be coupled to the processor for receiving the frames;
• at least one output configured to be coupled to the display device;
• graphics memory defining at least a first frame buffer and a second frame buffer, wherein at least one of the first frame buffer and the second frame buffer is capable of holding a virtual desktop image that cannot be entirely displayed on the screen;
• and
• additional circuitry coupled to the graphics memory and to the at least one output, wherein the additional circuitry is configured to assert, to the at least one output, a first set of filtered display data being computed from a first subset of the display data in the first frame buffer and that is associated with a first portal of the virtual desktop image, and the additional circuitry is configured to respond to at least one control signal during or after assertion of the first set of filtered display data to the at least one output, by asserting to the at least one output, a second set of filtered display data being computed from a second subset of the display data in at least one of the first frame buffer and the second frame buffer and that is associated with either a second portal of the virtual desktop image or a resized version of the first portal of the virtual desktop image, wherein each of the second portal and the resized version of the first portal is configurable to correspond to any region of the virtual desktop image.

A graphics unit for use in a computer system, the computer system including a display device having a display screen and a processor configured to generate frames of display data, said graphics unit including:

• at least one input configured to be coupled to the processor for receiving the frames;
• at least one output configured to be coupled to the display device;
• graphics memory defining at least a first frame buffer and a second frame buffer, wherein at least one of the first frame buffer and the second frame buffer is capable of holding a virtual desktop image that cannot be entirely displayed on the screen;
• and
• additional circuitry, coupled to the graphics memory and configured to assert, to at least one output, a first set of filtered display data being computed from a first subset of the display data in the first frame buffer and that is associated with a first portal of the virtual desktop image, wherein the first portal is configurable to correspond to any region of the virtual desktop image, wherein the additional circuitry is configured to respond to at least one control signal during or after assertion of the first set of filtered display data to the at least one output, by asserting to the at least one output a second set of filtered display data being computed from a second subset of the display data in the first frame buffer and that is associated with a second portal of the virtual desktop image at a predetermined location of said virtual desktop image,
• wherein the additional circuitry is also configured to assert, to the at least one output for simultaneous display, display data determined by at least a subset of a frame of data in the first frame buffer and indicative of the first portal of the virtual desktop image, and display data determined by at least a subset of a frame of data in the second frame buffer and indicative of a portal of a second virtual desktop image, wherein the second portal is configurable to correspond to any region of the virtual desktop image.

A method for displaying data indicative of a virtual desktop image on a display device having a display screen, said display screen having an available area for displaying the data indicative of the virtual desktop image, said method comprising the steps of:

• (a) storing display data in a frame buffer to cause the frame buffer to hold the virtual desktop image, wherein the virtual desktop image cannot be entirely displayed on the display screen;
• and
• (b) asserting a sequence of sets of filtered display data to the display device, wherein each of the sets is computed from a different subset of the display data in the frame buffer and is associated with a portal of the virtual desktop image, and each portal is configurable to correspond to any region of the virtual desktop,
• wherein step (b) includes the steps of sending at least one of said subsets of the display data from the frame buffer to a processor, filtering the at least one of said subsets of the display data in the processor to generate filtered display data, performing multi-display operations in the processor for generating multiple frames of filtered display data for simultaneous display, storing the filtered display data in a graphics memory, and asserting at least some of the filtered display data from the graphics memory to the display device.