Patent ID: 7372467
Filing Date: 2008-05-13
Classification: G06T

Abstract:
1. A texture unit for performing anisotropic texture mapping to produce filtered texture values, comprising: a sample modification unit configured to compute a spread equal or greater than one texel for a first number of texture samples based on a mip map level weight and compute a second number of texture samples for a first level of detail of a mip mapped texture using the spread, wherein the mip map level weight for a coarse level of detail of the mip mapped texture relative to the first level of detail is a fractional portion of a log base two of a minor axis length and the mip map level weight for a fine level of detail of the mip mapped texture relative to the first level of detail is a difference between one and the fractional portion of the log base two of the minor axis length and wherein the spread for the fine level of detail of the mip mapped texture is determined as two raised to a power of the mip map level weight for the coarse level of detail of the mip mapped texture and the spread for the coarse level of detail of the mip mapped texture is determined as a reciprocal of two raised to a power of the mip map level weight for the fine level of detail of the mip mapped texture; a sample spacing unit configured to position the second number of texture samples along a major axis of anisotropy according to the spread; and a filter unit configured to filter the second number of texture samples to produce a filtered texture value for an anisotropic pixel footprint.