C++ Game

asteroids.cpp

#include <iostream>
#include <vector>
#include <list>

#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>

#include "GameState.h"
#include "SplashScreen.cpp"
#include "AsteroidsGame.cpp"

SDL_Window *window = NULL;
SDL_Surface *surface = NULL;

bool init_sdl(){
    if (SDL_Init(SDL_INIT_VIDEO) != 0){
        return false;
    }else{
        window = SDL_CreateWindow("Asteroids", 100, 100, 800, 600, SDL_WINDOW_SHOWN);
        if (window == NULL){
            return false;
        }else{
            surface = SDL_GetWindowSurface(window);
            return true;
        }
    }
}

int main(){
    std::list<GameState*> gameStates;
    gameStates.push_back(new SplashScreen());
    gameStates.push_back(new AsteroidsGame());
    if (init_sdl()){
        IMG_Init(IMG_INIT_PNG);

        while (gameStates.size() > 0){
            GameState *state = gameStates.front();
            gameStates.pop_front();

            state->stateFinished = false;
            state->window = window;
            state->surface = surface;

            state->InitState();
            while (!state->stateFinished){
                state->HandleEvents();
                state->Update();
                state->Draw();
                //std::cout << SDL_GetError() << std::endl;
            }
        }
        SDL_DestroyWindow(window);
    }else{
        std::cerr << "Failed to initialize SDL." << std::endl;
    }
    SDL_Quit();
}

AsteroidsGame.cpp

#include <vector>
#include <iostream>

#include <SDL2/SDL.h>

#include "GameState.h"

class AsteroidsGame: public GameState{
    public:
        void Draw(){
            SDL_FillRect(surface, NULL, SDL_MapRGB(surface->format, 255, 0, 0));
            SDL_UpdateWindowSurface(window);
            SDL_Delay(1234);
            stateFinished = true;
        }
};

AsteroidsGame.h

#pragma once

#include "GameState.h"

class AsteroidsGame: public GameState{
}

GameState.cpp

#include <SDL2/SDL.h>
#include <iostream>

class GameState{
    public:
        virtual void InitState() {}
        virtual void HandleEvents() {}
        virtual void Update() {}
        virtual void Draw() {}
        
        bool stateFinished;
        SDL_Window *window;
        SDL_Surface *surface;
};

GameState.h

#pragma once

#include <SDL2/SDL.h>

class GameState{
    public:
        virtual void InitState() {};
        virtual void HandleEvents() {};
        virtual void Update() {};
        virtual void Draw() {};
        bool stateFinished;
        SDL_Window *window;
        SDL_Surface *surface;
};

SplashScreen.cpp

#include <vector>
#include <iostream>

#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>

#include "GameState.h"

class SplashScreen: public GameState{
    public:
        void InitState(){
            images.push_back(IMG_Load("SplashScreen/1.png"));
            images.push_back(IMG_Load("SplashScreen/2.png"));
        }

        void Draw(){
            for (int i=0;i<images.size();i++){
                std::cout << "Blitting image " << i << std::endl;
                SDL_BlitSurface(images[i], NULL, surface, NULL);
                SDL_UpdateWindowSurface(window);
                SDL_Delay(1500);
            }
            stateFinished = true;
        }

        std::vector<SDL_Surface*> images;
};

SplashScreen.h

#pragma once

#include <vector>

#include "GameState.h"

class SplashScreen: public GameState{
    public:
        std::vector<SDL_Surface*> images;
}