BLOCK LINEAR MEMORY ORDERING OF TEXTURE DATA

• US 20110169850A1
• Filed: 03/28/2011
• Published: 07/14/2011
• Est. Priority Date: 01/04/2005
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Kilgariff, Emmett M., Donovan, Walter E., McCormack, Joel J., Abdalla, Karim M.
• Granted Patent: US 8,436,868 B2
• Time in Patent Office: Days
• US Class Current: 345/552
• CPC Class Codes: G06T 1/60 Memory management
• CPC Class Codes: G06T 15/04 Texture mapping

Abstract

A method of organizing memory for storage of texture data, in accordance with one embodiment of the invention, includes accessing a size of a mipmap level of a texture map. A block dimension may be determined based on the size the mipmap level. A memory space (e.g., computer-readable medium) may be logically divided into a plurality of whole number of blocks of variable dimension. The dimension of the blocks is measured in units of gobs and each gob is of a fixed dimension of bytes. A mipmap level of a texture map may be stored in the memory space. A texel coordinate of said mipmap level may be converted into a byte address of the memory space by determining a gob address of a gob in which the texel coordinate resides and determining a byte address within the particular gob.

Claims

1. A computer-readable medium storing a plurality of instructions which when executed cause a computing device to implement a method comprising:

computing a coordinate in gobs of a texel as a function of a texel coordinate and a gob dimension in texels, wherein a dimension of each gob is a fixed number of bytes, and a plurality of gobs are a fixed size of a page of said memory space;

computing a coordinate in blocks of said texel as a function of said coordinate in gobs of said texel and a block dimension in gobs, wherein a dimension of each block is a variable number of said gobs but constant for a given mipmap level;

sequencing a plurality of blocks as a function of said coordinate in gobs of said texel, an image dimension in gobs, said coordinate in blocks of said texel and said block dimension in gobs, wherein each block is arranged in a given order of gobs;

sequencing a plurality of gobs in each of said plurality of blocks as a function of said coordinate in gobs and said block dimension in gobs, wherein each gob is arranged in a given order of bytes; and

computing a gob offset value as a function of said sequencing said plurality of block, said block dimension in gobs and said sequencing said plurality of gobs.

2. The computer-readable medium according to claim 1, wherein said computing said coordinate in gobs of said texel comprises:

computing an x-coordinate in gobs by bitwise right shifting an x-coordinate of said texel by a value of a gob width in texels;

computing a y-coordinate in gobs by bitwise right shifting a y-coordinate of said texel by a value of a gob height in texels; and

setting a z-coordinate in gobs to a z-coordinate of said texel.

3. The computer-readable medium according to claim 2, wherein said computing said coordinate in blocks of said texel as comprises:

computing an x-coordinate in blocks by bitwise right shifting said x-coordinate in gobs by a value of a block width in gobs;

computing a y-coordinate in blocks by bitwise right shifting said y-coordinate in gobs by a value of a block height in gobs; and

computing a z-coordinate in blocks by bitwise right shifting said z-coordinate in gobs by a value of a block depth in gobs.

4. The computer-readable medium according to claim 3, wherein said sequencing said plurality of block comprises:

computing a first product of said z-coordinate in blocks and an image height in blocks;

computing a first sum of said first product and said y-coordinate in blocks;

computing a second product of said first sum and an image width in blocks; and

computing a second sum of said second product and said x-coordinate in blocks.

5. The computer-readable medium according to claim 4, wherein said sequencing said plurality of blocks further comprises:

computing an x-coordinate in block gobs including;

computing a first mask by shifting bitwise left once said block width in gobs and subtracting one; and

combining said x-coordinate in gobs with said first mask utilizing a Boolean AND function;

computing a y-coordinate in block gobs including;

computing a second mask by shifting left once said block height in gobs and subtracting one; and

combining said y-coordinate in gobs with said second mask utilizing a Boolean AND function; and

computing a z-coordinate in block gobs including;

computing a third mask by shifting left once said block depth in gobs and subtracting one; and

combining said z-coordinate in gobs with said third mask utilizing a Boolean AND function.

6. The computer-readable medium according to claim 5, wherein said sequencing said plurality of gobs in each of said plurality of gobs comprises:

computing a third product of said z-coordinate in block gobs and said block height in gobs left shifted once;

computing a third sum of said third product and said y-coordinate in block gobs;

computing a fourth product of said third sum and said block width in gobs left shifted once; and

computing a fourth sum of said fourth product and said x-coordinate in block gobs.

7. The computer-readable medium according to claim 6, wherein said computing said gob offset value comprises:

computing a fifth sum of said block width in gobs, said block height in gobs and said block depth in gobs; and

computing a sixth sum of said second sum left shifted by said fifth sum and said fourth sum.

8. The computer-readable medium according to claim 1, wherein said computing said gob offset value is relative to a start of a given miplevel.

9. The computer-readable medium according to claim 1, further comprising computing said block dimension in gobs for a given miplevel as a function of a dimension of said given miplevel, a gob dimension in texels and a base block dimension in gobs of a base miplevel.

10. The computer-readable medium according to claim 9, wherein said computing said block dimension in gobs for a given miplevel further comprises:

computing a block width in gobs as a function of a width of said given miplevel, a gob width in texels and a block width of said base miplevel;

computing a block height in gobs as a function of a height of said given miplevel, a gob height in texels and a block height of said base miplevel; and

computing a block depth in gobs as a function of a depth of said given miplevel and a block depth of said base miplevel.

11. The computer-readable medium according to claim 9, wherein said block dimension is a class interface parameter of said base miplevel.

12. A computer-readable medium containing instructions which when executed cause a computing device to implement method of block linear memory ordering comprising:

computing a block width in gobs as a function of a width of a given miplevel, a gob width in texels and a block width of said base miplevel;

computing a block height in gobs as a function of a height of said given miplevel, a gob height in texels and a block height of said base miplevel; and

computing a block depth in gobs as a function of a depth of said given miplevel and a block depth of said base miplevel, wherein said block dimension is measured in units of gobs arranged in a given order in each block and wherein each gob is of a fixed dimension of bytes and provides a level of organization of said memory space for storing texels in addition to said blocks.

13. The computer-readable medium according to claim 12, wherein said block dimension is reduced as said given mipmap level of said texture mipmap increases.

14. The computer-readable medium according to claim 12, wherein said fixed dimension of each gob is a three dimensional measure.

15. A computing device comprising:

a processor, for determining a color and a depth value for each pixel of a display;

a computer-readable medium, communicatively coupled to said processor, for storing texture data utilized for said determining said color for each pixel;

a memory controller, communicatively coupled to said processor and said computer-readable medium, for mapping a virtual address of a texture to a physical address in said computer-readable medium by computing a block dimension in gobs as a function of a dimension of said given mipmap level, a gob dimension in texels and a base block dimension in gobs of a base mipmap level, wherein said block dimension is measured in units of gobs arranged in a given order in each block and wherein each gob is of a fixed dimension of bytes and provides a level of organization of said memory space for storing texels in addition to said blocks.

16. The computing device of claim 15, wherein said mipmap is defined by its type, a dimension of a base level, a number of array elements, a texel type and a block size.

17. The computing device of claim 15, wherein said dimension of said blocks are adjusted down as a miplevel of said mipmap decreases.

18. The computing device of claim 15, wherein a plurality of blocks of said mipmap are arranged in an xyz ordering.

19. The computing device of claim 15, wherein a dimension of said plurality of blocks are dynamically adjusted as a function of a dimension of a miplevel of said mipmap, a partition size of said computer-readable medium and a configuration of said computer-readable medium.

20. The computing device of claim 15, wherein an organization of said texel data is selected from the group consisting of a one-dimension mipmapped texture, a two-dimensional mipmapped texture, a two-dimensional texture array, a two-dimensional cube map and a three-dimensional mipmapped texture.