| 摘要 |
Disclosed is an apparatus and method for generating a lighting value based on a number of lighting factors. A lighting accelerator first converts an ambient portion, a diffuse light portion, and a specular light portion of the lighting factors into the log domain. Then, data combination units operate on the lighting factors after they have been converted. Then, the lighting factors are converted back from the log domain using anti-log processing. Converting the lighting factors into the log domain is accomplished by using a series of linear equations using coefficients that are all based on powers of two, and are therefore easily calculable. Further, while in the log domain, the specular light portion of the lighting factor is operated on by a special purpose multiplier that uses a truncated partial product tree, saving area and power with only a negligible amount of error. |
