TECHNIQUES FOR LATCHING INPUT EVENTS TO DISPLAY FLIPS

• US 20140028574A1
• Filed: 07/26/2012
• Published: 01/30/2014
• Est. Priority Date: 07/26/2012
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: McCaffrey, Jonathan Baird, Barris, Robert Charles, Zhang, Chi
• Granted Patent: US 9,823,935 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 9/451 Execution arrangements for user interfaces

Abstract

A system including one or more input interface drivers, an input dispatcher, one or more applications, a system compositor and one or more output interface drivers. The input interface driver receives input events. The input dispatcher is modified to dispatch a current input event to a corresponding application after receiving an indication that a display image based upon a previous input event has been posted to an output interface driver. The corresponding application renders a new display image based upon the current input event. The system compositor posts the new display image to the output interface driver. The system compositor is also modified to send an indication to the input dispatcher that the new display image has been posted to the output interface driver. The system iteratively performs the process to latch the dispatching of input events to the display flip.

Claims

1. A method comprising:

receiving, by an input interface driver, a given input event;

dispatching, by an input dispatcher, the given input event to an application after receiving an indication that an invalidate-based display image based upon a previous input event has been posted to an output interface driver;

rendering, by the application, an invalidate-based display image based upon the given input event;

posting, by a system compositor, the invalidate-based display image based upon the given input event to the output interface driver; and

sending, from the system compositor to the input dispatcher, an indication that the invalidate-based display image based upon the given input event has been posted to the output interface driver.

2. The method according to claim 1, further comprising:

receiving, by the input interface driver, a next input event;

dispatching, by the input dispatcher, the next input event to the application after receiving the indication that the invalidate-based display image based upon the given input event has been posted to the output interface driver;

rendering, by the application, an invalidate-based display image based upon the next input event;

posting, by the system compositor, the invalidate-based display image based upon the next input event to the output interface driver; and

sending, from the system compositor to the input dispatcher, an indication that the invalidate-based display image based upon the next input event has been posted to the output interface driver.

3. The method according to claim 1, further comprising:

requesting a Unix pipe between the system compositor and the input dispatcher over and an inter-process call (IPC) mechanism; and

wherein receiving the indication that the invalidate-based display image based upon the given input event has been posted to the output interface comprises passing an invalidate signal through the Unix pipe from the system compositor to the input dispatcher.

4. The method according to claim 1, further comprising:

receiving, by the input interface driver, a plurality of compatible input events;

appending the plurality of compatible input events together as a coalesced input event;

dispatching, by the input dispatcher, the coalesced input event to the application after receiving the indication that the invalidate-based display image based upon the given input event has been posted to the output interface driver;

rendering, by the application, an invalidate-based display image based upon the coalesced input event;

posting, by the system compositor, the invalidate-based display image based upon the coalesced input event to the output interface driver; and

sending, from the system compositor to the input dispatcher, an indication that the invalidate-based display image based upon the coalesced input event has been posted to the output interface driver.

5. The method according to claim 1, wherein sending, from the system compositor to the input dispatcher, the indication that the invalidate-based display image based upon the previous input event has been posted to the output interface driver enables delivery of the next input event to the application in time to be rendered by a next display refresh cycle.

6. The method according to claim 1, wherein dispatching of input events is synchronized to a rendering rate of the application if the application renders as a rate slower than a refresh rate of a display.

7. The method according to claim 1, wherein dispatching of input events is synchronized to a refresh rate of a display if the application renders as a rate faster than the refresh rate of a display.

8. The method according to claim 1, wherein a rendering buffer becomes available to the application for rendering the invalidate-based display image based upon the next input event when the invalidate-based display image based upon the previous input event is posted by the system compositor to the output interface driver.

9. The method according to claim 1, wherein the given input event comprises an x-y coordinate position of a user finger or stylus sensed by the input interface driver.

10. One or more computing device readable media storing one or more sets of computing device executable instructions which when executed by one or more processing units implement a system comprising:

an input interface driver to receive input events;

an input dispatcher to dispatch a current input event to a corresponding application after receiving an indication that a display image based upon a previous input event has been posted to an output interface driver;

the corresponding application to render a new display image based upon the current input event; and

a system compositor to post the new display image to the output interface driver and to send an indication that the new display image has been posted to the output interface driver, wherein the indication that the new display image based upon the current input event has been posted becomes the indication that the display image based upon the previous input event has been posted at the input dispatcher.

11. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 10, wherein the input interface driver comprises a touch sensor device driver.

12. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 10, wherein the output interface, driver comprises a display device driver.

13. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 10, wherein the input interface driver and output interface driver comprise a touch screen device driver.

14. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 10, wherein the input dispatcher comprises an InputDispatcher of an Android operating system modified to dispatch the current input event to the corresponding application after receiving the indication that the display image based upon the previous input event has been posted to the output interface driver.

15. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 14, wherein the input dispatcher comprises an SurfaceFlinger of the Android operating system modified to send the indication that the new display image has been posted to the output interface driver to the InputDispatcher.

16. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 14, further comprising a Unix pipe between the SurfaceFlinger and the InputDispatcher for sending the indication that the new display image has been posted to the output interface driver from the SurfaceFlinger to the InputDispatcher.

17. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 14, wherein the input events are dispatched on a per application basis.

18. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 14, wherein input events for each applicable application are queued separately for dispatching by the input dispatcher.

19. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 14, wherein the input events are dispatched for all applications.

20. The one or more computing device readable media including one or more sets of computing device executable instructions which when executed by the one or more processing units implement the system according to claim 14, wherein input events are system-wide queued for dispatching by the input dispatcher.