I am building my first opengl app. I have been following the tutorials here http://www.rastertek.com/gl40tut03.html

I would like some explanation as to how the author know what calls to make next. Like what is the flow of initializing opengl?

looking at the InitializeExtensions method, he sets the devicecontext, then sets a pixel format and then creates a rendering context. So what decides what should be initialized before or after? is there a diagram where I can visualize as to what should be init first?

Thanks

interesting, glew should be very useful! at first site, i was totally disgusted by putting all those typedefs and proc addresses in my project. I wished there was a simpler way so glew seems to be the way to go. What other benefits does one get from SDL2.0. It says it provides lowlevel access to the video buffer, audio output, mouse and keyboard. Isn't all that available in opengl?

everything to do with rendering is available in opengl - the benefit to SDL is that it also gives you input, sound, some file io, texture loading help, and other stuff.. opengl basically gives you access to functions that can manipulate the graphics card - you have to do everything else (or use other libraries to help - like loading images from file in to textures for example - I would definitely use some library to help with that)

if your going to be doing direct opengl calls then you should definitely be using GLEW or some such thing.. dont forget to initialize it before making any opengl calls

I also ran into SFML (http://www.sfml-dev.org/documentation/2.1/) it seems to be doing the same function as SDL. What do you guys think of SFML?

If you like low-level libraries, use SDL (it's C). If you like higher level libraries and object oriented stuff, use SFML (C++).

The only issue I can see that would override your preference above is smart phone/tablet support. SFML still shows iOS and Android support as "soon", so SDL is probably more mature and a safer bet if you're going to target smart phones and tablets.