Method and apparatus for sampling non-power of two dimension texture maps
AssigneeNVIDIA Corporation
InventorsWalter E. Donovan, Rajeev Jayavant
Life of this patent
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Abstract
An apparatus and method for using non-power of two texture maps is described. Normalized texture map coordinates such as s and t are converted from a floating point format to a fixed point format and wrapping operations are performed to produce unnormalized texture map coordinates such as u and v corresponding to non-power of two texture maps.
Claims20
A method of processing a normalized texture map coordinate corresponding to a non-power of two texture map, comprising:
- receiving the normalized texture map coordinate corresponding to the non-power of two texture map represented in a floating point format;
- applying a wrap function to the normalized texture map coordinate to produce a wrapped texture map coordinate that is represented as a fixed point value,
- wherein the normalized texture map coordinate has a fixed point value between 0 and size_LOD, where size_LOD is the size of a dimension in texels for the non-power of two texture map, the normalized texture map coordinate value being used to determine an address of a texel within the non-power of two texture map.
A method of using a non-power of two texture map, comprising:
- receiving a normalized texture map coordinate corresponding to the non-power of two texture map represented in a floating point format;
- determining if the texture map is a cube map, and if not, then;
- converting the normalized texture map coordinate to a fixed point format to produce a fixed point normalized texture map coordinate;
- and
- processing the fixed point normalized texture map coordinate based on a wrapping mode to produce a wrapped texture map coordinate.
A computer readable medium that includes a set of instructions that when executed by a graphics processing unit causes the processing unit to determine texture map coordinates for non-power of two texture maps by performing the steps of:
- receiving a normalized texture coordinate corresponding to the non-power of two texture map represented in a floating point format;
- converting the normalized texture coordinate to a fixed point format;
- performing a wrap operation to produce a wrapped texture coordinate for the non-power of two texture map;
- and
- receiving the wrapped texture coordinate;
- and
- scaling the wrapped texture coordinate by a non-power of two LOD dimension of the non-power of two texture map to produce an unnormalized texture map coordinate.
Dependencies are inferred from the claim text.