Apparaus and method for dynamically programming a window ID configuration based on an application environment

• US 20040183810A1
• Filed: 03/20/2003
• Published: 09/23/2004
• Est. Priority Date: 03/20/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Tesauro, James Stanley, Ramsay, George F. III, Marion, Neal Richard
• Granted Patent: US 6,911,991 B2
• Time in Patent Office: Days
• US Class Current: 345/581
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables
• CPC Class Codes: G09G 5/14 Display of multiple viewports

Abstract

The present invention provides a mechanism by which the number of bits used to identify the WIDs for each of the color buffer and the overlay buffer may be programmed into the graphics adapter based on the currently active application environment. With the apparatus and method of the present invention, a programmable WAT color size selection device is provided in a RAMDAC of the graphics adapter. This programmable WAT color size selection device may be dynamically programmed to use varying bit splits of a WID from a WID buffer to obtain different indexes into a color WAT table and an overlay WAT table. In this way, different splits of, for example, an eight bit WID may be obtained based on the setting of the programmable WAT color size selection device such that varying color and overlay capabilities are obtainable dynamically.

Claims

1. A method of generating a graphical display on a display device of a computing device, comprising:

receiving control data to set a number of bits of a window ID for indexing into a window attribute table;

reading a window ID from a window ID buffer;

splitting the window ID into a first set of bits and a second set of bits according to the number of bits for indexing into the window attribute table set based on the control signal; and

generating the graphical display using at least one entry obtained from at least one window attribute table, wherein the at least one entry is identified by at least one of the first set of bits and the second set of bits.

2. The method of claim 1, wherein the number of bits of a window ID for indexing into a window attribute table is a number of bits of a window ID for indexing into a color window attribute table.

3. The method of claim 1, wherein generating the graphical display using at least one entry obtained from at least one window attribute table includes:

sending the first set of bits to a color window attribute table;

sending the second set of bits to an overlay window attribute table;

obtaining a first entry in the color window attribute table based on the first set of bits being an index into the color window attribute table; and

obtaining a second entry in the overlay window attribute table based on the second set of bits being an index into the overlay window attribute table.

4. The method of claim 3, further comprising:

receiving data from a color buffer;

receiving data from an overlay buffer; and

generating the graphical display based on the data from the color buffer, data from the overlay buffer, the first entry and the second entry.

5. The method of claim 4, wherein the graphical display is generated by a RAMDAC staged pipeline which receives, as input, the data from the color buffer, data from the overlay buffer, the first entry and the second entry.

6. The method of claim 1, wherein the control data is received from a graphics device driver in response to a request from an application to set a window attribute table color size.

7. The method of claim 6, wherein the request is generated by the application upon opening a window of the application.

8. The method of claim 6, wherein the graphics device driver is an XServer device driver.

9. The method of claim 1, further comprising:

dynamically setting at least one register identifying a split of the window ID bits, wherein the control data is dynamically received in response to an application requesting a set of graphical parameters to be supported by a graphics adapter.

10. A computer program product in a computer readable medium for generating a graphical display on a display device of a computing device, comprising:

first instructions for receiving control data to set a number of bits of a window ID for indexing into a window attribute table;

second instructions for reading a window ID from a window ID buffer;

third instructions for splitting the window ID into a first set of bits and a second set of bits according to the number of bits for indexing into the window attribute table set based on the control signal; and

fourth instructions for generating the graphical display using at least one entry obtained from at least one window attribute table, wherein the at least one entry is identified by at least one of the first set of bits and the second set of bits.

11. The computer program product of claim 10, wherein the number of bits of a window ID for indexing into a window attribute table is a number of bits of a window ID for indexing into a color window attribute table.

12. The computer program product of claim 10, wherein the fourth instructions for generating the graphical display using at least one entry obtained from at least one window attribute table include:

instructions for sending the first set of bits to a color window attribute table;

instructions for sending the second set of bits to an overlay window attribute table;

instructions for obtaining a first entry in the color window attribute table based on the first set of bits being an index into the color window attribute table; and

instructions for obtaining a second entry in the overlay window attribute table based on the second set of bits being an index into the overlay window attribute table.

13. The computer program product of claim 12, further comprising:

instructions for receiving data from a color buffer;

instructions for receiving data from an overlay buffer; and

instructions for generating the graphical display based on the data from the color buffer, data from the overlay buffer, the first entry and the second entry.

14. The computer program product of claim 13, wherein the graphical display is generated by a RAMDAC staged pipeline which receives, as input, the data from the color buffer, data from the overlay buffer, the first entry and the second entry.

15. The computer program product of claim 10, wherein the control data is received from a graphics device driver in response to a request from an application to set a window attribute table color size.

16. The computer program product of claim 15, wherein the request is generated by the application upon opening a window of the application.

17. The computer program product of claim 15, wherein the graphics device driver is an XServer device driver.

18. The computer program product of claim 10, further comprising:

fifth instructions for dynamically setting at least one register identifying a split of the window ID bits, wherein the control data is dynamically received in response to an application requesting a set of graphical parameters to be supported by a graphics adapter.

19. An apparatus for generating a graphical display on a display device of a computing device, comprising;

means for receiving control data to set a number of bits of a window ID for indexing into a window attribute table;

means for reading a window ID from a window ID buffer;

means for splitting the window ID into a first set of bits and a second set of bits according to the number of bits for indexing into the window attribute table set based on the control signal; and

means for generating the graphical display using at least one entry obtained from at least one window attribute table, wherein the at least one entry is identified by at least one of the first set of bits and the second set of bits.

20. The apparatus of claim 19, wherein the number of bits of a window ID for indexing into a window attribute table is a number of bits of a window ID for indexing into a color window attribute table.

21. The apparatus of claim 19, wherein the means for generating the graphical display using at least one entry obtained from at least one window attribute table includes:

means for sending the first set of bits to a color window attribute table;

means for sending the second set of bits to an overlay window attribute table;

means for obtaining a first entry in the color window attribute table based on the first set of bits being an index into the color window attribute table; and

means for obtaining a second entry in the overlay window attribute table based on the second set of bits being an index into the overlay window attribute table.

22. The apparatus of claim 21, further comprising:

means for receiving data from a color buffer;

means for receiving data from an overlay buffer; and

means for generating the graphical display based on the data from the color buffer, data from the overlay buffer, the first entry and the second entry.

23. The apparatus of claim 22, wherein the graphical display is generated by a RAMDAC staged pipeline which receives, as input, the data from the color buffer, data from the overlay buffer, the first entry and the second entry.

24. The apparatus of claim 19, wherein the control data is received from a graphics device driver in response to a request from an application to set a window attribute table color size.

25. The apparatus of claim 24, wherein the request is generated by the application upon opening a window of the application.

26. The apparatus of claim 24, wherein the graphics device driver is an XServer device driver.

27. The apparatus of claim 19, further comprising:

means for dynamically setting at least one register identifying a split of the window ID bits, wherein the control data is dynamically received in response to an application requesting a set of graphical parameters to be supported by a graphics adapter.

28. An apparatus for generating a graphical display on a display device of a computing device, comprising:

a window ID buffer;

a programmable window attribute table color size selection device coupled to the window ID buffer;

a color window attribute table device coupled to the programmable window attribute table color size selection device;

an overlay window attribute table device coupled to the programmable window attribute table color size selection device;

a staged pipeline coupled to the color window attribute table and the overlay window attribute table;

a color buffer coupled to the staged pipeline; and

an overlay buffer coupled to the staged pipeline, wherein the programmable window attribute table color size selection device is dynamically programmable based on control data received from a software graphics device driver to thereby change a window ID split from a first window ID split to a second window ID split.