A METHOD OF DETERMINING TEXTURE MAP PARAMETERS TO DEFINE A FOOTPRINT IN A GRAPHICS PROCESSOR AND DEVICE THEREOF

摘要

The present invention discloses a method of determining texture map parameters to define a footprint representing a projection of a pixel onto a texture map in a graphics processor. The method comprises computing ellipse coefficients based on a pair of specified partial derivative vectors ( U x , V x ) and ( u y , v y ); computing differential value t based on the ellipse coefficients in log scale; determine a range AngleRg within which the direction value of the footprint a lies, and getting reference differential value t' to which the differential value t approximates; and fetching the reference direction value of the footprint a' in the range AngleRg from a LUT corresponding to the reference differential value t'. The present invention results in improved performance compared with exact computation of the texture mapping parameters and favorable image quality compared with simple approximation of the texture mapping parameters.