sdl, sdl2 error: SDL_window (among others) not declared - c++

Question

I have played around with C++ for a while and just recently started to get into SDL and SDL2.
I was able to get the dot demo program to work.
But other programs, such as Lazy Foo' Productions's copied and pasted don't seem to work.
I have both SDL and SDL2 installed (and uninstalled and reinstalled.) I am on Ubuntu 15.04 and I have the IDE CodeBlocks linked (-ISDL2)
The errors are SDL_Window - SDL_WINDOWPOS_UNDEFINED - SDL_WINDOW_SHOWN - SDL_CreateWindow - SDL_GetWindowSurface - SDL_UpdateWindowSurface and finally, SDL_DestroyWindow -- was not declared in this scope.
Also, I include:
#include </usr/include/SDL/SDL.h>
#include </usr/include/SDL2/SDL.h>
#include <stdio.h>
I'm pretty sure that I don't need all of that location, but it didn't work without it either. One other note, when I type the #includes, CodeBlocks will suggest SDL2/SDL.h but not SDL/SDL.h.
What am I missing?
I don't think I can put Lazy Foo' code here - I didn't get permission...

Answer 1

The code you listed;
#include </usr/include/SDL/SDL.h>
#include </usr/include/SDL2/SDL.h>
#include <stdio.h>
Why don't you change it to
#include <SDL2/SDL.h>
#include <stdio.h>
as the first header is where SDL_CreateWindow and other SDL2 functions are declared?
Also you don't need to include both SDL and SDL2 headers. Indeed that could very well be the source of your problem as you would only need to include the version you're using.
If you're following the tutorials from lazyfoo's site, you can check if the ones you're following are using SDL1.2 or SDL2 from their table of contents, as the site actually have the tutorials for both versions.
UPDATE:
I didn't notice that your platform is a Linux platform. Then it is so much easier to solve your problem. The demo that you followed previously was done using SDL-1.2, whereas the gcc error hinted that you're using SDL-2.0, hence SDL_CreateWindow and other undefined errors. You should install SDL-2.0 library and SDL-2.0 development files (which will provide you with the necessary SDL-2.0 headers). You may refer this to SDL-2.0 packages provided by your platform distribution.
As for the compilation, it'll be the same as the tutorial you've followed with a minor change, instead of gcc sdltest.o -lSDL -o sdltest, you'll issue gcc sdltest.o -lSDL2 -o sdltest to indicate that you're linking your code against SDL2 library.
EDIT
A simple SDL program to test your environment. You can use any of the simpler text editor such as nano or gedit or others to edit this, and run the compilation command above to test your setup.
The simplest way to do this is by copy the code, then from your terminal, issue cat > sdltest.cpp and paste the code, then hit [ENTER] and [CTRL-C] to end it. Then you can issue the compilation command as mentioned previously,g++ sdltest.cpp -lSDL2 -o sdltest.
Code;
#include <SDL2/SDL.h>
#include <stdio.h>
int main()
{
SDL_Window *p;
SDL_Renderer *w;
p = SDL_CreateWindow("Game",SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,800,640,SDL_WINDOW_SHOWN);
w = SDL_CreateRenderer(p, -1, 0);
SDL_RenderClear(w);
SDL_SetRenderDrawColor(w,255,0,0,255);
SDL_Rect Rect = {220,140,200,200};
SDL_RenderFillRect(w,&Rect);
SDL_RenderPresent(w);
SDL_Delay(3000);
SDL_DestroyRenderer(w);
SDL_DestroyWindow(p);
SDL_Quit();
return 0;
}
Hope that helps.