More to the point, how does one turn the god mode on?
You didn't intend to, but you just showed how useless source code is for ordinary users.. Why, you might ask. Let me tell you.
God mode is done much faster by doing it the ordinary way. You either use cheat code or you use the combo of Cheat Engine+Ollydbg to disable functions that decrease health. Both of these things are done much faster this way, and to both open and closed source games. There is no reason for the source code here.
the code is open sourced, and that will never change.
Are you sure? Are you absolute certain? Do you feel lucky, punk?
Scientists will study your brain to learn more about your distant cousin, Man.