Your application is lacking of inclusions and we don't even know about possible errors during the building phase.
You're asking for gles 2 but you're using things like glMatrixMode which aren't gles2 apis - don't include gl. H, use gles2. H instead - that's got the api you're asking for in it.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.