I’m going through this tutorial and a few details (maybe not too critical) seem off. For example, this is written:
All of the code in ofApp.h is wrapped in a large if statement called #ifndef. This statement is designed explicitly for the preProcessor stage of compilation. Basically, when the compiler runs through your code before it compiles, it copies and pastes code to make all of the include statements work. If you have included the same header file in multiple places, this can cause a problem for compilation. #ifndef tells the compiler that if whatever variable name you have decided, in this case, _TEST_APP, has already been defined somewhere in the code, not to define it again. It’s sort of a hack to make organizing code easier, and is good practice to include in any custom classes you make (with a different variable name obviously).
This does not seem to accurately represent the recent oF version. The page appears to have been last updated in 2008. Are there any plans to update it again?