SYSTEMS AND METHODS FOR GENERATING TRANSLATED DISPLAY IMAGE BASED ON ROTATION OF A DISPLAY DEVICE

• US 20090141045A1
• Filed: 11/30/2007
• Published: 06/04/2009
• Est. Priority Date: 11/30/2007
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Inventors: Jackson, Adam
• Granted Patent: US 9,202,444 B2
• Time in Patent Office: Days
• US Class Current: 345/649
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G09G 2340/0492 Change of orientation of the displayed image, e.g. upside-down, mirrored
• CPC Class Codes: G09G 2370/04 Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
• CPC Class Codes: G09G 5/391 Resolution modifying circuits, e.g. variable screen formats

Abstract

Embodiments relate to systems and methods for generating address information to translate the order in which memory locations are accessed in a video buffer, to maintain a desired orientation in a rotated display. A video buffer is filled with display data to drive a CRT, LCD, or other display screen, starting with the upper-left corner. When the user rotates the display screen, the display screen continues to scan from the same starting corner, resulting in a misaligned orientation. In embodiments, a correct orientation can be automatically generated by determining a scan direction for the rotated display. The physical location of the new logical starting pixel is determined, and the rows and columns of the display image are rendered in a revised logical order which compensates for the amount and direction of rotation.

Claims

1. A method of processing display data, comprising:

receiving display data for generating a display image on a display device;

receiving notification of a rotation of the display device, the notification comprising rotation information; and

generating a logical scan direction for displaying pixels of the display image based on the rotation information to maintain the display image in a predetermined orientation.

2. The method of claim 1, wherein the step of generating a logical scan direction comprises determining a logical initial pixel of the display image.

3. The method of claim 2, wherein the logical initial pixel comprises a corner pixel of the display image.

4. The method of claim 2, wherein the step of generating a logical scan direction comprises iteratively generating a next logical pixel adjacent to the current pixel, until an edge of the display device is reached.

5. The method of claim 4, wherein the step of generating a logical scan direction comprises advancing to a new row or column of the display image when the edge of the display device is reached.

6. The method of claim 1, wherein the rotation of the display device comprises rotation by an integer multiple of 90 degrees.

7. The method of claim 1, wherein the display image is displayed in a display mode comprising one of a landscape mode and a portrait mode.

8. The method of claim 1, wherein the predetermined orientation comprises a vertical orientation.

9. The method of claim 1, wherein the step of generating a logical scan direction comprises generating a set of display parameters comprising at least display height information, display width information, pixel dot pitch information, logical initial pixel information, and initial traverse axis information.

10. The method of claim 1, wherein the display data is stored in a video buffer memory.

11. The method of claim 10, wherein the step of generating a logical scan direction comprises generating an address of video buffer memory corresponding to a current logical pixel.

12. The method of claim 11, wherein the address of video buffer memory is generated by an address generator communicating with video display circuitry.

13. A display system, comprising:

a video buffer memory for receiving display data for generating a display image on a display device;

display circuitry, communicating with the video buffer memory, the display circuitry generating a video output signal to display the display image on the display device; and

an address generator, communicating with the display circuitry, the address generator generating a series of memory locations corresponding to a logical scan direction of the display image to maintain the display image in a predetermined orientation, based on receipt of notification of rotation information for the display device.

14. The system of claim 13, wherein the logical scan direction comprises a logical initial pixel of the display image.

15. The system of claim 14, wherein the logical initial pixel comprises a corner pixel of the display image.

16. The system of claim 14, wherein the address generator iteratively generates a next logical pixel adjacent to the current pixel, until an edge of the display device is reached.

17. The system of claim 16, wherein the address generator generates an address to advance to a new row or column of the display image when the edge of the display device is reached.

18. The system of claim 13, wherein the rotation of the display device comprises rotation by an integer multiple of 90 degrees.

19. The system of claim 13, wherein the display image is displayed in a display mode comprising one of a landscape mode and a portrait mode.

20. The system of claim 13, wherein the predetermined orientation comprises a vertical orientation.

21. The system of claim 13, wherein the logical scan direction is based on a set of display parameters comprising at least display height information, display width information, pixel dot pitch information, logical initial pixel information, and initial traverse axis information.

22. The system of claim 13, wherein the display device comprises at least one of a liquid crystal display, a cathode ray tube display, a plasma display, a display integrated in a portable media device, and a video display device.

23. A computer-readable medium, the computer-readable medium being readable to execute a method of display processing comprising:

receiving display data for generating a display image on a display device, receiving notification of a rotation of the display device, the notification comprising rotation information; and

generating a logical scan direction for displaying pixels of the display image based on the rotation information to maintain the display image in a predetermined orientation.

24. The computer-readable medium of claim 23, wherein the step of generating a logical scan direction comprises determining a logical initial pixel of the display image.

25. The computer-readable medium of claim 24, wherein the logical initial pixel comprises a corner pixel of the display image.