Lighting, as discussed in the previous chapter, is largely implementation independent. Most techniques have to do more with the physical laws of the world than with OpenGL or DirectX. Texturing, on the other hand, is a bag full of API-dependent tricks. Environment mapping, bump mapping, and more generally, texture combiners are very close to the metal, and thus research on API-specific methods is needed.
I suggest you complete this reading with a lengthy visit to a web site or package of your choice. The DirectX SDK is full of advanced texturing samples that cover all topics explained in this chapter as well as many new subjects. As for OpenGL programmers, both NVIDIA and ATI have well laid out developer sites, where interesting demos can be downloaded and new tricks learned.