This chapter provides the details of the functions that are defined as part of the OpenGL Shading Language. Feel free to skip ahead to the next chapter if you want to get down to the nitty-gritty of writing your own shaders. This chapter can be useful as a reference after you are well on your way to writing OpenGL shaders for your own application.
The OpenGL Shading Language defines an assortment of built-in convenience functions for scalar and vector operations. The reasons for providing built-in functions for the OpenGL Language include
Making shaders simpler to develop and easier to understand and maintain.
Exposing some necessary hardware functionality in a convenient way such as accessing a texture map. The language ...