the opengl functions that you use have been deprecated for nearly 15 years. the fixed function pipeline should only be used by legacy code. if you write new code, you should consider switching to modern opengl, that is opengl 3.1 or above. you can find a really good introduction to modern opengl on learnopengl.com for example. glenableclientstate, gldisableclientstate, glvertexpointer and glnormalpointer are all part of the fixed function pipeline and shouldn't be used nowadays. in case that what you pasted is indeed legacy code, excuse my comment