OpenGL是一个图形硬件的软件接口这一接口包含了数百个函数，图形程序员可以利用这些函数指定设计高品质的三维彩色图像所需的对象和操作。这些函数中有许多实际上是其他函数的简单变形，因此，实际上它仅包含大约180个左右完全不同的函数。 -OpenGL is a graphics hardware software interface (" GL"　is Graphics Library). This interface contains hundreds of functions, graphics programmer can use these function to specify the design of high-quality three-dimensional color images of objects and operations needed. Many of these functions are actually simple deformation of other functions, so in fact it contains only about 180 or so completely different function. OpenGL Utility Library (OpenGL Utility Library, GLU) and the X window system, OpenGL extensions (OpenGL Extension to the X Window System, GLX) to provide useful support for OpenGL features and full set of OpenGL core functions. This book describes in detail the function of these functions.