Abstract: A texture filtering unit and a method are disclosed that provide multiple variants of an approximate trilinear filtering operation. A texture sampling and filtering unit may be configured to determine a level-of-detail (LOD) value for a sample point in texture space, and select, based on the LOD value, a fine mip-level and a coarse mip-level from the mip-map. The closer of the two selected mip-levels to the sample point is determined, and farther of the two selected mip-levels from the sample point is determined. A first quad of texels in the closer mip-level and a second quad of texels in the farther mip-level are then determined. A total of five or fewer texels are selected from the first quad of texels and from the second quad of texels. A filtered value for the sample point is determined based on an approximate trilinear filtering operation on the selected texels.

Abstract: A texture filtering unit and a method are disclosed that provide multiple variants of an approximate trilinear filtering operation. A texture sampling and filtering unit may be configured to determine a level-of-detail (LOD) value for a sample point in texture space, and select, based on the LOD value, a fine mip-level and a coarse mip-level from the mip-map. The closer of the two selected mip-levels to the sample point is determined, and farther of the two selected mip-levels from the sample point is determined. A first quad of texels in the closer mip-level and a second quad of texels in the farther mip-level are then determined. A total of five or fewer texels are selected from the first quad of texels and from the second quad of texels. A filtered value for the sample point is determined based on an approximate trilinear filtering operation on the selected texels.

Abstract: Devices and methods provide data from multiple storage locations to a processor. A data block containing data required by a processor is stored in two or more locations, e.g., in a local memory and a system memory, both of which are accessible to the processor's memory interface. The memory interface directs each read request for mirrored data to one or another of the mirror locations. Selection of a mirror location to be read is based on substantially real-time information about which mirror location is best able to handle the request. For instance, the selection of a mirror location to access can be based at least in part on information about the level of activity on various buses that connect the processor to the mirror locations.

Abstract: Floating-point texture filtering units leverage existing fixed-point filter circuits. Groups of floating-point texture values are converted to products of a fixed-point mantissa and a scaling factor that is the same for each texture value in the group. The fixed-point mantissas are filtered using a fixed-point filter circuit, and the filtered mantissa is combined with the scaling factor to determine a floating-point filtered value. Multiple floating-point filter results may be combined in a floating-point accumulator circuit. The same fixed-point filter circuit may also be used to filter fixed-point texture data by providing fixed-point input path that bypasses the format conversion and a fixed-point accumulator.

Abstract: A method and system for performing a texture operation with user-specified offset positions are disclosed. Specifically, one embodiment of the present invention sets forth a method, which includes the steps of deriving a first destined texel position based on an original sample position associated with a pixel projected in a texture map and a first offset position specified by a user and fetching texel attributes at the first destined texel position for the texture operation.

Abstract: Anisotropic optimization is a technique to reduce the number of texture samples anisotropically filtered to determine a texture value associated with a graphics fragment. Reducing the number of texture samples anisotropically filtered reduces the number of texture samples read from memory and speeds up the filter computation. A programmable bias is used to control the number of texture samples used during anisotropic filtering, permitting a user to determine a balance between improved texture map performance and anisotropic texture filtering quality.

Abstract: A method and system for performing texture mapping across adjacent texture maps. Specifically, one embodiment of the present invention sets forth a method, which includes the steps of determining whether a texel crosses a boundary of a first texture map, examining a first texture state identifier associated with the first texture map, and requesting for a second texture state identifier associated with a second texture map that is adjacent to the first texture map to enable traversal to the second texture map to access the texel if the first texture state identifier includes a mode indicative of wrapping to an adjacent texture map and texture adjacency information that points to a second texture map.

Abstract: A method and system for performing a texture operation with user-specified offset positions are disclosed. Specifically, one embodiment of the present invention sets forth a method, which includes the steps of deriving a first destined texel position based on an original sample position associated with a pixel projected in a texture map and a first offset position specified by a user and fetching texel attributes at the first destined texel position for the texture operation.

Abstract: Floating-point texture filtering units leverage existing fixed-point filter circuits. Groups of floating-point texture values are converted to products of a fixed-point mantissa and a scaling factor that is the same for each texture value in the group. The fixed-point mantissas are filtered using a fixed-point filter circuit, and the filtered mantissa is combined with the scaling factor to determine a floating-point filtered value. Multiple floating-point filter results may be combined in a floating-point accumulator circuit. The same fixed-point filter circuit may also be used to filter fixed-point texture data by providing fixed-point input path that bypasses the format conversion and a fixed-point accumulator.

Abstract: Floating-point texture filtering units leverage existing fixed-point filter circuits. Groups of floating-point texture values are converted to products of a fixed-point mantissa and a scaling factor that is the same for each texture value in the group. The fixed-point mantissas are filtered using a fixed-point filter circuit, and the filtered mantissa is combined with the scaling factor to determine a floating-point filtered value. Multiple floating-point filter results may be combined in a floating-point accumulator circuit. The same fixed-point filter circuit may also be used to filter fixed-point texture data by providing fixed-point input path that bypasses the format conversion and a fixed-point accumulator.

Abstract: Anisotropic optimization is a technique to reduce the number of texture samples anisotropically filtered to determine a texture value associated with a graphics fragment. Reducing the number of texture samples anisotropically filtered reduces the number of texture samples read from memory and speeds up the filter computation. A programmable bias is used to control the number of texture samples used during anisotropic filtering, permitting a user to determine a balance between improved texture map performance and anisotropic texture filtering quality.

Abstract: The current invention involves new systems and methods for reorganizing a texture sampling order that is used to read texels from a texel cache. When anisotropic filtering is used to process the texels read from the texel cache, the texels are read in an order based on a major axis alignment. Reorganizing texture sampling order to use the order based on the major axis alignment results in improved texel cache locality, thereby improving texel cache performance.