Function Calls For using textures

I am sure that I am being dense here, but I cannot find any explination of the functions to fetch values from textures. I have found the function calls for setting up and binding textures to memory in the programers guide.

I got tex2d() from an example. After reading some of the forums I am sure there are more function calls.

Could some one direct me to documentation on the other function calls.


Section 4.4.5, pages 26-27.