Method and apparatus for approximating a signed value between two endpoint values in a three-dimensional image rendering device

摘要

A method and apparatus for providing a correctly signed result of a linear interpolation (LIRP) function in a compute controlled display system. A correctly signed LIRP evaluation may be performed by simply adding a bias to each of the operands of the LIRP function and subtracting the bias to the result. Adding the bias is achieved by inverting the high (sign) bit of each of the operands. Subtracting the bias is achieved by inverting the high (sign) bit of the result.