hello, I am newbie here. I have learned C++ and OpenGL in Computer Engineering in my university curriculum. But I dun have real working experience in game development and C++, But I would like to pick up the knowledge again. I would like to ask about these two books. As I can find them in online resources for earlier release, I am a little confused whether I should buy them. So I would like to ask whether it is necessary to buy these two books, are there many new things added? Thank you very much for your help.

By buying the book you have hard copy, and there are slightly more up to date versions but if you dig around online you can find references to the newer features. Plus OpenGL 3.0/3.1 are out and about which do things a little differently if you are targeting directx 10 level features. Just starting out, get through the online versions until you feel its necessary to buy books.