Target independent stenciling in graphics processing

Patent metadata

Field	Value
Publication number	US-9299181-B2
Application number	US-201414321309-A
Country	US
Kind code	B2
Filing date	Jul 1, 2014
Priority date	Aug 28, 2013
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

In an example rendering graphics data includes determining a stencil parameter that indicates a sampling rate for determining a coverage value for each antialiased pixel of a path of an image, determining, separately from the stencil parameter, a render target parameter that indicates a memory allocation for each antialiased pixel of the path, and rendering the path using the stencil parameter and the render target parameter.

First claim

What is claimed is:

1. A method of rendering graphics data, the method comprising:
determining a stencil sampling rate for determining a coverage value for each of one or more antialiased of a path of an image, wherein the stencil sampling rate indicates, for each of the antialiased pixels, a memory allocation in a stencil buffer for storing samples of each of the antialiased pixels sampled at the stencil sampling rate;
determining, separately from the stencil sampling rate, a render target parameter having a value that is less than the stencil sampling rate, wherein the render target parameter indicates, for each of the antialiased pixels, a memory allocation in a frame buffer for storing each rendered antialiased pixel of the path; and
rendering the path using the stencil sampling rate and the render target parameter.

2. The method of claim 1 , further comprising determining a depth parameter that is a different value than the stencil sampling rate.

3. The method of claim 2 , wherein determining the depth parameter comprises determining a depth parameter that is equal to the render target parameter, wherein the depth parameter indicates a depth of each of the antialiased pixels of the path relative to one or more other pixels.

4. The method of claim 1 , further comprising determining a rasterization parameter that is a different value than the render target parameter, wherein the rasterization parameter indicates a rasterization sampling rate for each of the antialiased pixels of the path.

5. The method of claim 1 , wherein rendering the path comprises:
rendering the path to the stencil buffer using the stencil sampling rate, wherein the stencil buffer indicates antialiased pixels of the path to be shaded;
rasterizing the path using the render target parameter and the stencil buffer.

6. The method of claim 5 , further comprising:
determining, while rendering the path to the stencil buffer, a bounding box for the path, wherein determining the bounding box comprises determining a plurality of maximum boundary points of the path; and
wherein rasterizing the path comprises rasterizing the bounding box using the render target parameter and the stencil buffer such that determining the bounding box for the path and rasterizing the path are performed in one rendering pass.

7. The method of claim 6 , wherein determining the plurality of maximum boundary points of the path comprises determining an upper boundary point, a lower boundary point, a right boundary point and a left boundary point.

8. An apparatus for rendering graphics, the apparatus comprising:
a stencil buffer configured to store samples of antialiased pixels sampled at a stencil sampling rate, the antialiased pixels forming at least a portion of a path of an image;
a frame buffer configured to store rendered antialiased pixels; and
a graphics processing unit (GPU) configured to:
determine a stencil sampling rate for determining a coverage value for each of one or more antialiased pixels of a path of an image, wherein the stencil sampling rate indicates, for each of the antialiased pixels, a memory allocation in a stencil buffer for storing samples of each of the antialiased pixels sampled at the stencil sampling rate;
determine, separately from the stencil sampling rate, a render target parameter having a value that is less than the stencil sampling rate, wherein the render target parameter indicates, for each of the antialiased pixels, a memory allocation in a frame buffer for storing each rendered antialiased pixel of the path; and
render the path using the stencil sampling rate and the render target parameter.

9. The apparatus of claim 8 , wherein the GPU is further configured to determine a depth parameter that is a different value than the stencil sampling rate.

10. The apparatus of claim 9 , wherein to determine the depth parameter, the GPU is configured to determine a depth parameter that is equal to the render target parameter, wherein the depth parameter indicates a depth of each of the antialiased pixels of the path relative to one or more other pixels.

11. The apparatus of claim 8 , wherein the GPU is further configured to determine a rasterization parameter that is a different value than the render target parameter, wherein the rasterization parameter indicates a rasterization sampling rate for each of the antialiased pixels of the path.

12. The apparatus of claim 8 , wherein to render the path, the GPU is configured to:
render the path to the stencil buffer using the stencil sampling rate, wherein the stencil buffer indicates antialiased pixels of the path to be shaded;
rasterize the path using the render target parameter and the stencil buffer.

13. The apparatus of claim 12 , wherein the GPU is further configured to:
determine, while rendering the path to the stencil buffer, a bounding box for the path, wherein determining the bounding box comprises determining a plurality of maximum boundary points of the path; and
wherein to rasterize the path, the GPU is configured to rasterize the bounding box using the render target parameter and the stencil buffer such that determining the bounding box for the path and rasterizing the path are performed in one rendering pass.

14. The apparatus of claim 13 , wherein to determine the plurality of maximum boundary points of the path, the GPU is configured to determine an upper boundary point, a lower boundary point, a right boundary point and a left boundary point.

15. An apparatus for rendering graphics data, the apparatus comprising:
means for determining a stencil sampling rate for determining a coverage value for each of one or more antialiased pixels of a path of an image, wherein the stencil sampling rate indicates, for each of the antialiased pixels, a memory allocation in a stencil buffer for storing samples of each of the antialiased pixels sampled at the stencil sampling rate;
means for determining, separately from the stencil sampling rate, a render target parameter having a value that is less than the stencil sampling rate, wherein the render target parameter indicates, for each of the antialiased pixels, a memory allocation in a frame buffer for storing each rendered antialiased pixel of the path; and
means for rendering the path using the stencil sampling rate and the render target parameter.

16. The apparatus of claim 15 , further comprising means for determining a depth parameter that is a different value than the stencil sampling rate.

17. The apparatus of claim 16 , wherein the means for determining the depth parameter comprises means for determining a depth parameter that is equal to the render target parameter, wherein the depth parameter indicates a depth of each of the antialiased pixels of the path relative to one or more other pixels.

18. The apparatus of claim 15 , further comprising means for determining a rasterization parameter that is a different value than the render target parameter, wherein the rasterization parameter indicates a rasterization sampling rate for each of the antialiased pixels of the path.

19. The apparatus of claim 15 , wherein the means for rendering the path comprises:
means for rendering the path to the stencil buffer using the stencil sampling rate, wherein the stencil buffer indicates antialiased pixels of the path to be shaded;
means for rasterizing the path using the render target parameter and the stencil buffer.

20. The apparatus of claim 19 , further comprising:
means for determining, while rendering the path to the stencil buffe

Assignees

• Qualcomm Inc

Inventors

• Goel Vineet
• Ceylan Usame

Classifications

• G06T11/23

  using straight lines or curves · CPC title

• G06T11/10

  Texturing; Colouring; Generation of textures or colours (retouching, inpainting or scratch removal G06T5/77) · CPC title

• G06T1/20

  Processor architectures; Processor configuration, e.g. pipelining · CPC title

• G06T15/80

  Shading · CPC title

• G06T11/40

  Filling planar surfaces by adding surface attributes, e.g. adding colours or textures · CPC title