Abstract: There is provided a method for compressing texture values comprising: assigning texture values in a YUV format; packing the texture values into 32-bit words; and color promoting the texture values to 8-bit values. The YUV format has a Y component for every pixel sample, and U/V (they are also named Cr and Cb) components for every fourth sample. Every U/V sample coincides with four (2×2) Y samples. A single 32-bit word contains four packed Y values, one value each for U and V, and optionally four one-bit Alpha components as follows: YUV_0566-5-bits each of four Y values, 6-bits each for U and V; and YUV_1544-5-bits each of four Y values, 4-bits each for U and V, four 1-bit Alphas. The color promotion converts these components from 4-, 5-, or 6-bit values to 8-bit values. This method yields compression from 96 bits down to 32 bits, or 3:1 compression.

Abstract: In accordance with the present invention, the rate of change of texture addresses when mapped to individual pixels of a polygon is used to obtain the correct level of detail (LOD) map from a set of prefiltered maps. The method comprises a first determination of perspectively correct texture address values found at four corners of a predefined span or grid of pixels. Then, a linear interpolation technique is implemented to calculate a rate of change of texture addresses for pixels between the perspectively bound span corners. This linear interpolation technique is performed in both screen directions to thereby create a level of detail value for each pixel. The YUV formats described above have Y components for every pixel sample, and UN (they are also named Cr and Cb) components for every fourth sample. Every UN sample coincides with four (2×2) Y samples. This is identical to the organization of texels in U.S. Pat. No.

Abstract: In accordance with the present invention, the rate of change of texture addresses when mapped to individual pixels of a polygon is used to obtain the correct level of detail (LOD) map from a set of prefiltered maps. The method comprises a first determination of perspectively correct texture address values found at four corners of a predefined span or grid of pixels. Then, a linear interpolation technique is implemented to calculate a rate of change of texture addresses for pixels between the perspectively bound span corners. This linear interpolation technique is performed in both screen directions to thereby create a level of detail value for each pixel. The YUV formats described above have Y components for every pixel sample, and UN (they are also named Cr and Cb) components for every fourth sample. Every UN sample coincides with four (2×2) Y samples. This is identical to the organization of texels in U.S. Pat. No.

Abstract: In accordance with the present invention, the rate of change of texture addresses when mapped to individual pixels of a polygon is used to obtain the correct level of detail (LOD) map from a set of prefiltered maps. The method comprises a first determination of perspectively correct texture address values found at four corners of a predefined span or grid of pixels. Then, a linear interpolation technique is implemented to calculate a rate of change of texture addresses for pixels between the perspectively bound span corners. This linear interpolation technique is performed in both screen directions to thereby create a level of detail value for each pixel. The YUV formats described above have Y components for every pixel sample, and UN (they are also named Cr and Cb) components for every fourth sample. Every UN sample coincides with four (2×2) Y samples. This is identical to the organization of texels in U.S. Pat. No.

Abstract: A method and apparatus, in a computer graphics display system, for producing Anisotropic Texture using constant density object space stochastic sampling. The approach of this invention uniformly samples the footprint of the pixel as mapped into a texture array to determine what complete and fractional texels are covered by the pixel's projected footprint. The sample density remains a constant and is determined by the area of the pixel footprint projection in texture space. Due to variations in footprint projections, each pixel may require a different number of samples, but the sample per texel density remains approximately constant. The intensity is the average of the sample points within the footprint.