Graphic processor performing sampling-based rendering and method of operating the same

1. A method of operating a graphic processor, the method comprising:

performing intermediate rendering by shading-processing some fragments of a first frame by using a first sample candidate map having a first pattern;

performing intermediate rendering by shading-processing some fragments of a second frame by using a first sample candidate map having a second pattern;

additionally sampling other fragments of the second frame by using a second sample candidate map generated by changing sampling information of the first sample candidate map having the first pattern or the first sample candidate map having the second pattern, based on comparing a shading processing result of the first frame and a shading processing result of the second frame; and

performing final rendering, which comprises shading-processing fragments sampled by using the second sample candidate map.

2. The method of claim 1 , further comprising performing interpolation processing on remaining fragments of the second frame that are not shading-processed in the intermediate rendering and the final rendering on the second frame.

3. The method of claim 1 , wherein the

final rendering comprises:

shading-processing other fragments of the first frame, after performing of the intermediate rendering on the first frame; and

performing interpolation processing on remaining fragments of the first frame that are not shading-processed in the intermediate rendering and the final rendering on the first frame.

4. The method of claim 1 , wherein a position of a fragment in the first frame sampled by the first sample candidate map having the first pattern differs from a position of a fragment in the second frame sampled by the first sample candidate map having the second pattern.

5. The method of claim 1 , further comprising selecting any one of a sampling off mode, a fine sampling mode, and a coarse sampling mode,

wherein, when the coarse sampling mode is selected, said other fragments of the second frame are additionally sampled by using the shading processing results of the first frame and the second frame.

6. The method of claim 5 , further comprising:

changing an operation mode into the sampling off mode;

receiving a third frame; and

performing rendering by shading-processing all fragments of the third frame.

7. The method of claim 5 , further comprising:

changing an operation mode into the fine sampling mode;

receiving a third frame;

performing intermediate rendering by shading-processing some fragments of the third frame by using a first sample candidate map having a third pattern; and

performing final rendering by additionally sampling and shading-processing other fragments of the third frame by using a shading processing result of the third frame,

wherein the third pattern has a higher sampling rate than the second pattern.

8. A graphic processor comprising:

an intermediate rendering processor performing shading processing on some of a plurality of fragments of a current frame according to sampling information of a sample candidate map;

a sample candidate map revising circuit configured to change the sampling information of the sample candidate map to thereby generate a changed sample candidate map, based on a comparison of a shading processing result of a previous frame and a shading processing result of the current frame; and

a final rendering processor performing shading processing on fragments of the current frame additionally sampled according to the changed sample candidate map among the fragments that are not shading-processed by the intermediate rendering processor.

9. The graphic processor of claim 8 , further comprising an interpolation processor performing hole filling on a fragment that is not shading-processed by the intermediate rendering processor and the final rendering processor.

10. The graphic processor of claim 8 , further comprising a sample candidate map generator generating the sample candidate map according to received pattern information.

11. The graphic processor of claim 10 , wherein

the sample candidate map has a first pattern in rendering processing on an odd frame and has a second pattern different from the first pattern in rendering processing on an even frame, and

the previous frame corresponds to the odd frame and the current frame corresponds to the even frame.

12. The graphic processor of claim 11 , further comprising a sample pattern generator providing pattern information having the first pattern or the second pattern to the sample candidate map generator according to a frame order.

13. The graphic processor of claim 12 , further comprising a pixel extractor receiving fragment values according to the shading processing result of the previous frame, receiving the pattern information having the first pattern from the sample pattern generator when the pattern information having the second pattern is provided to the sample candidate map generator, and providing a fragment value corresponding to the first pattern of the previous frame to the sample candidate map revising circuit.

14. The graphic processor of claim 10 , further comprising an interpolation accuracy determining circuit performing interpolation accuracy determination by comparing a value calculated by interpolation processing with a value calculated by shading processing with respect to the same fragment of the current frame,

wherein the sample candidate map generator adjusts a sampling rate of the sample candidate map according to a result of the interpolation accuracy determination.

15. The graphic processor of claim 10 , wherein the sample candidate map generator adjusts a sampling rate of the sample candidate map in response to a command from a host.

16. The graphic processor of claim 8 , wherein the sample candidate map revising circuit revises the sample candidate map by using the shading processing result of the previous frame and the shading processing result of the current frame when a sampling rate of the sample candidate map is less than a reference value, and revises the sample candidate map by using the shading processing result of the current frame when the sampling rate of the sample candidate map is greater than the reference value.

17. A graphic processor comprising:

a sample candidate map revising circuit configured to receive a first sample candidate map for selecting some of a plurality of fragments with respect to a given frame of a video to be rendered, and generating a second sample candidate map by changing sampling information of the first sample candidate map based on a comparison of shading processing results of at least two frames of the video; and

a fragment processor performing intermediate rendering processing by shading processing on fragments sampled according to the first sample candidate map and performing final rendering processing by shading processing on fragments additionally sampled according to the second sample candidate map.

18. The graphic processor of claim 17 , wherein the fragment processor comprises:

an intermediate rendering processor performing the intermediate rendering processing; and

a final rendering processor performing the final rendering processing.

19. The graphic processor of claim 17 , further comprising a sample candidate map generator receiving pattern information and generating the first sample candidate map according to the pattern information,

wherein the sample candidate map revising circuit revises the first sample candidate map by using a shading processing result of a previous frame and a shading processing result of a current frame when a sampling rate of the first sample candidate map is less than a reference value, and revises the first sample candidate map by using the shading processing result of the current frame when the sampling rate of the first sample candidate map is greater than the reference value.