Method and apparatus for displaying rotated images
A graphics system includes a single buffer coupled between a graphics controller and a display controller. The graphics controller rotates a frame generated by an application and writes the rotated frame into the buffer. The rotation is performed a segment (e.g., a quartile of a frame) at a time. Each time the display controller completes displaying a frame quartile, the display controller signals the graphics controller to rotate a corresponding quartile of a next frame. The reduction in buffer space reduces power consumption and improves performance of the system.
1 . A method comprising:
displaying a partial frame of a current frame stored in a display buffer; and
replacing the partial frame of the current frame with a corresponding partial frame of a next frame upon completion of displaying the partial frame of the current frame.
2 . The method of claim 1 wherein the replacing further comprises:
rotating the corresponding partial frame of the next frame; and
writing the corresponding partial frame into the display buffer.
3 . The method of claim 1 wherein displaying further comprises:
signaling an interrupt to indicate an end of displaying a partial frame.
4 . The method of claim 3 further comprising:
waiting on the interrupt to begin rotating the corresponding partial frame.
5 . The method of claim 1 wherein displaying further comprises:
entirely displaying the current frame before displaying the partial frame of the next frame.
6 . An apparatus comprising:
a graphics controller to rotate a frame;
a display controller to control displaying the frame; and
a memory including a display buffer coupled between the graphics controller and the display controller, wherein the graphics controller writes into the display buffer a partial frame of a next frame before the display controller completes displaying an entire frame of a current frame.
7 . The apparatus of claim 6 wherein the display controller further comprises:
a synchronization interface to send an interrupt signal to the graphics controller, the signal indicating an end of displaying the partial frame.
8 . The apparatus of claim 6 wherein the graphics controller further comprises:
a synchronization interface to receive an interrupt signal from the display controller, the signal prompting the frame rotation.
9 . The apparatus of claim 6 wherein the graphics controller further comprises:
a processing engine to rotate a corresponding partial frame of the next frame after a partial frame of the current frame is displayed.
10 . The apparatus of claim 6 further comprising:
a processing core to issue a rotation command to the graphics controller.
11 . The apparatus of claim 10 wherein the memory further comprises:
a pair of buffers accessible by the processing core and the graphics controller to store the current frame and the next frame before the rotation.
12 . The apparatus of claim 10 wherein the processing core, the memory, the graphics controller, and the display controller are located on a single chip.
13 . A system comprising:
a graphics controller to rotate a frame;
a display controller to control displaying the frame;
a memory including a display buffer coupled between the graphics controller and the display controller, wherein the graphics controller writes into the display buffer a partial frame of a next frame before the display controller completes displaying an entire frame of a current frame; and
a battery to power the graphics controller, the display controller, and the memory.
14 . The system of claim 13 wherein the display controller further comprises:
a synchronization interface to send a signal to the graphics controller, the signal indicating an end of displaying the partial frame.
15 . The system of claim 13 wherein the graphics controller further comprises:
a synchronization interface to receive a signal from the display controller, the signal prompting the frame rotation.
16 . The system of claim 13 wherein the graphics controller further comprises:
a processing engine to rotate a corresponding partial frame of the next frame after a partial frame of the current frame is displayed.
17 . The system of claim 13 further comprising:
a processing core to issue a rotation command to the graphics controller.
18 . The system of claim 17 wherein the memory further comprises:
a pair of buffers accessible by the processing core and the graphics controller to store the current frame and the next frame before the rotation.
19 . The system of claim 17 wherein the processing core, the memory, the graphics controller, and the display controller are located on a single chip.