Method and apparatus for interleaved processing of direct and indirect texture coordinates in a graphics system

• US 7,307,638 B2
• Filed: 06/15/2005
• Issued: 12/11/2007
• Est. Priority Date: 08/23/2000
• Status: Expired due to Term

• Current Assignee: Nintendo Company Limited
• Original Assignee: Nintendo Company Limited
• Inventors: Leather, Mark M., Drebin, Robert A., Van Hook, Timothy J.
• Primary Examiner(s): Sajous, Wesner
• Application Number:
  US11/152,283
• Publication Number:
  US 20050237337A1
• Time in Patent Office: 909 Days
• Field of Search: 345418-428, 345581-587, 345/606, 345/619, 345629-630, 345/501, 345/545, 345/552, 345/563, 382/285, 382/305, 382/300, 463 30- 34
• US Class Current: 345/582
• CPC Class Codes: G06T 15/005 General purpose rendering architectures
• CPC Class Codes: G06T 15/04 Texture mapping

Abstract

A graphics system including a custom graphics and audio processor produces exciting 2D and 3D graphics and surround sound. The system includes a graphics and audio processor including a 3D graphics pipeline and an audio digital signal processor. The graphics pipeline renders and prepares images for display at least in part in response to polygon vertex attribute data and texel color data stored as a texture images in an associated memory. An efficient texturing pipeline arrangement achieves a relatively low chip-footprint by utilizing a single texture coordinate/data processing unit that interleaves the processing of logical direct and indirect texture coordinate data and a texture lookup data feedback path for “recirculating” indirect texture lookup data retrieved from a single texture retrieval unit back to the texture coordinate/data processing unit. Versatile indirect texture referencing is achieved by using the same texture coordinate/data processing unit to transform the recirculated texture lookup data into offsets that may be added to the texture coordinates of a direct texture lookup. A generalized indirect texture API function is provided that supports defining at least four indirect texture referencing operations and allows for selectively associating one of at least eight different texture images with each indirect texture defined. Retrieved indirect texture lookup data is processed as multi-bit binary data triplets of three, four, five, or eight bits. The data triplets are multiplied by a 3×2 texture coordinate offset matrix before being optionally combined with regular non-indirect coordinate data or coordinate data from a previous cycle/stage of processing. Values of the offset matrix elements are variable and may be dynamically defined for each cycle/stage using selected constants. Two additional variable matrix configurations are also defined containing element values obtained from current direct texture coordinates. Circuitry for optionally biasing and scaling retrieved texture data is also provided.

Claims

1. In a graphics system having a memory containing texture data, a method of indirect texture referencing comprising the steps of:

(a) using indirect texture coordinates to generate a data triplet;

(b) deriving texture coordinates based at least in part on the generated triplet; and

(c) using at least the derived texture coordinates to map predetermined texture data onto a primitive.

2. A method of indirect texture referencing as in claim 1 wherein the using step (a) includes referencing, in a texture memory, an array that maps the triplet via the indirect texture coordinates.

3. A method of indirect texture referencing as in claim 1 wherein the using step (a) includes fetching predetermined triplet data from a texture map stored in memory.

4. A method of indirect texture referencing as in claim 1 wherein the using step (c) includes referencing, in a texture memory, an array that maps color value data via the derived texture coordinates.

5. A method of indirect texture referencing as in claim 1 wherein the deriving step (b) performs a matrix multiplication operation wherein a first matrix comprising a plurality of predetermined constant and/or variable scalar elements is multiplied by a second matrix comprising a retrieved data triplet.

6. A method of indirect texture referencing as in claim 1 wherein a triplet comprises s, t and u texture coordinate offsets.

7. A method of indirect texture referencing as in claim 1 wherein a triplet comprises three eight-bit binary values.

8. A method of indirect texture referencing as in claim 1 wherein a triplet comprises three five-bit binary values.

9. A method of indirect texture referencing as in claim 1 wherein a triplet comprises three four-bit binary values.

10. A method of indirect texture referencing as in claim 1 wherein a triplet comprises three three-bit binary values.

11. A method of indirect texture referencing as in claim 1 wherein a quadruplet of indirect texture coordinates are processed together to produce a quadruplet of derived texture coordinates for mapping texture data to polygons.

12. A method of indirect texture referencing as in claim 5 wherein said first matrix comprises elements that are a scalar function of one or more predetermined texture coordinates.

13. A method of indirect texture referencing as in claim 5 wherein said first matrix is a 3×

2 matrix comprising six predetermined scalar elements.

14. A method of indirect texture referencing as in claim 5 wherein said first matrix is arranged having elements as follows:

15. A method of indirect texture referencing as in claim 5 wherein said first matrix is arranged having elements as follows:

16. In a 3D videographics system having a memory containing texture data stored in a texture memory, the texture data accessed via either a set of direct texture coordinates or a set of indirect texture coordinates, a method of indirect texture referencing for mapping a predetermined texture onto a polygon comprising the steps of:

(a) using a set of indirect texture-coordinates to retrieve a data triplet stored in texture memory;

(b) deriving a set of modified texture coordinates based at least in part on the retrieved data triplet; and

(c) using the set of modified texture coordinates to reference texture data stored in texture memory corresponding to the predetermined texture.

17. A method of indirect texture referencing as in claim 16 wherein the deriving step (b) includes performing at least one matrix multiplication operation wherein a first matrix comprising a plurality of predetermined constant and/or variable scalar elements is multiplied by a second matrix comprising a retrieved data triplet.

18. A method of indirect texture referencing as in claim 16 wherein the using step (c) includes referencing, in a texture memory, an array that maps color value data via the derived texture coordinates.

19. A method of indirect texture referencing as in claim 16 wherein a data triplet comprise at least one texture coordinate offset.

20. A method of indirect texture referencing as in claim 16 wherein a data triplet comprises s, t, and u texture coordinate offset values.

21. A method of indirect texture referencing as in claim 16 wherein a data triplet comprises three eight-bit binary values.

22. A method of indirect texture referencing as in claim 16 wherein a data triplet comprises three five-bit binary values.

23. A method of indirect texture referencing as in claim 16 wherein a data triplet comprises three four-bit binary values.

24. A method of indirect texture referencing as in claim 16 wherein a data triplet comprises three three-bit binary values.

25. A method of indirect texture referencing as in claim 17 wherein said first matrix comprises elements that are a scalar function of one or more predetermined direct texture coordinates.

26. A method of indirect texture referencing as in claim 17 wherein said first matrix is a 3×

2 matrix comprising six predetermined scalar elements.

27. A method of indirect texture referencing as in claim 17 wherein said first matrix is arranged having elements as follows:

28. A method of indirect texture referencing as in claim 17 wherein said first matrix is arranged having elements as follows:

29. In a graphics system having a memory containing texture data, a method of indirect texture referencing comprising the steps of:

(a) using a set of indirect texture-coordinates to retrieve offset data from the memory;

(b) multiplying the offset data by predetermined values forming elements of a texture offset matrix to produce a set of texture offset coordinates; and

(c) using said set of offset texture coordinates for referencing texture data stored in the memory when mapping a predetermined texture to a rendered polygon.

30. A method of indirect texture referencing as in claim 29 wherein said offset data is a result of a predetermined texturing function and comprises at least one texture coordinate offset value.

31. A method of indirect texture referencing as in claim 29 wherein said offset data comprises a set of three values for producing said set of texture offset coordinates.

32. A method of indirect texture referencing as in claim 31 wherein said set of three values comprise s, t and u coordinate offset data.

33. A method of indirect texture referencing as in claim 29 wherein said matrix elements comprise a set of predetermined constants.

34. A method of indirect texture referencing as in claim 29 wherein said matrix elements comprise a set of constant and variable values.

35. A method of indirect texture referencing as in claim 29 wherein one or more elements of said matrix are a mathematical function of one or more predetermined texture coordinates.

36. A method of indirect texture referencing as in claim 29 wherein the matrix is a 3×

2 matrix comprising six predetermined scalar elements.

37. A method of indirect texture referencing as in claim 29 wherein the matrix is arranged having elements as follows:

38. A method of indirect texture referencing as in claim 29 wherein the matrix is arranged having elements as follows:

39. In a graphics system including a graphics engine that renders and displays images at least in part in response to polygon vertex data and texture data stored in an associated memory, a texture processing subsystem for selectively mapping texture data corresponding to one or more different textures and/or texture characteristics to surfaces of said rendered and displayed images, said texture processing subsystem including a texture coordinate offset matrix arrangement producing a set of offset texture coordinates by multiplying indirect texture data by elements of a matrix, wherein one or more elements of the matrix are a mathematical function of one or more predetermined direct texture coordinates.

40. A texture processing subsystem as in claim 39 wherein the matrix has six elements in three rows and two columns.

41. A texture processing subsystem as in claim 39 wherein the matrix is arranged having elements as follows:

42. A texture processing subsystem as in claim 39 wherein the matrix is arranged having elements as follows:

43. In a graphics system including a graphics engine that renders and displays images at least in part in response to vertex data and texture data stored in an associated memory, a texture processing subsystem for selectively mapping texture data corresponding to one or more different textures and/or texture characteristics to surfaces of said rendered and displayed images, said texture processing subsystem including a texture coordinate offset matrix arrangement for producing a set of offset texture coordinates by multiplying indirect texture data by elements of a matrix, wherein one or more elements of the matrix can be selectively loaded.

44. A texture processing subsystem as in claim 43 wherein said elements are predetermined constants.

45. A texture processing subsystem as in claim 43 wherein one or more of said elements are a mathematical function of one or more predetermined direct texture coordinates.

46. A texture processing subsystem as in claim 43 wherein the matrix has six elements in three rows and two columns.