iOS OpenGL ES guide

http://ofps.oreilly.com/titles/9780596804824/chquick.html

http://developer.apple.com/library/ios/#documentation/3DDrawing/Conceptual/OpenGLES_ProgrammingGuide/WorkingwithEAGLContexts/WorkingwithEAGLContexts.html

http://issuu.com/blowupdaisy/docs/opengles_programmingguide