#ifndef INCLUDES_H_INCLUDED
#define INCLUDES_H_INCLUDED

#include<SDL.h>
#include<SDL_image.h>
#include<iostream>
#include<cstdlib>
#include<time.h>
#include<math.h>
#include <windows.h>

using namespace std;

#endif // INCLUDES_H_INCLUDED

Game.h:

#ifndef GAME_H_INCLUDED
#define GAME_H_INCLUDED

#include"includes.h"

#include "SDL.h"
class Game
{
public:
 Game();
 ~Game();
 bool init();
 void render();
 void update();
 void handleEvents();
 void clean();
 bool running() { return m_bRunning; }
private:
 SDL_Window* m_pWindow;
 SDL_Renderer* m_pRenderer;
 bool m_bRunning;
};
#endif // GAME_H_INCLUDED

Game.cpp:

#include "Game.h"
bool Game::init(const char* title, int xpos, int ypos, int width, int height, int flags)
{
 // attempt to initialize SDL
 if(SDL_Init(SDL_INIT_EVERYTHING) == 0)
 {
        std::cout << "SDL init success\n";
        // init the window
        m_pWindow = SDL_CreateWindow(title, xpos, ypos, width, height, flags);
        if(m_pWindow != 0) // window init success
        {
            std::cout << "window creation success\n";
            m_pRenderer = SDL_CreateRenderer(m_pWindow, -1, 0);
            if(m_pRenderer != 0) // renderer init success
            {
                std::cout << "renderer creation success\n";
                SDL_SetRenderDrawColor(m_pRenderer,
                255,255,255,255);
            }
            else
            {
                std::cout << "renderer init fail\n";
                return false; // renderer init fail
            }
        }
        else
        {
            std::cout << "window init fail\n";
            return false; // window init fail
        }
    }
    else
    {
        std::cout << "SDL init fail\n";
        return false; // SDL init fail
    }
    std::cout << "init success\n";
    m_bRunning = true; // everything inited successfully,start the main loop
    return true;
}

void Game::render()
{
 SDL_RenderClear(m_pRenderer); // clear the renderer tothe draw color
 SDL_RenderPresent(m_pRenderer); // draw to the screen
}

void Game::handleEvents()
{
    SDL_Event event;
    if(SDL_PollEvent(&event))
    {
        switch (event.type)
        {
            case SDL_QUIT:
            m_bRunning = false;
            break;
            default:
            break;
        }
    }
}

void Game::clean()
{
 std::cout << "cleaning game\n";
 SDL_DestroyWindow(m_pWindow);
 SDL_DestroyRenderer(m_pRenderer);
 SDL_Quit();
}

main.cpp:

#include "Game.h"

// our Game object
Game* g_game = 0;
int main(int argc, char* argv[])
{
 g_game = new Game();
 g_game->init("Chapter 1", 100, 100, 640, 480, 0);
 while(g_game->running())
 {
 g_game->handleEvents();
 g_game->update();
 g_game->render();
 }
 g_game->clean();
 return 0;
}

In Game.h, change:

bool init();

to:

bool init(const char* title, int xpos, int ypos, int width, int height, int flags);

The arguments on the declaration (line in Game.h) and the definition (line in Game.cpp) must be the same. Actually, the name of the arguments can be different (I'm not sure why anyone would want that, but it's valid), but the number and types must match.

@DiegoSLTS is correct. You can also skip the parameter names in your header, as they are not needed by the compiler, they are there only for your convenience.

Some feedback:

In includes.h, you have

using namespace std;

In general, you should avoid the using namespace construct in headers, as it pollutes the global namespace for all source files that include the infected headers.

Also, you should include as little as possible in headers. If you have a lot of #include-s in headers, the compilation will slow down. AFAIR, you can forward declare most SDL types.

I don't know why the Game would be a pointer (you plan to make it a global variable?). I'd use a normal variable on the stack, and I would also run the cleanup code in Game's destructor.

Sorry for the late response, but Im back to this now! I think I was close to figuring that out, but somehow got confused. Thanks alot for the help, it did get a bit more clearer now!

After that I put a "//" before the: g_game->update(); , since I wherent having any update function yet. And I also added the code

Game::Game(){}

using namespace std;