J'essaie de comprendre la bibliothèque SDL2 en C ++ et ne peut pas sembler configurer correctement le code pour dessiner simplement un rectangle à l'écran. Que devrais-je faire différemment?

#include <SDL.h>
bool success = true;  //success flag for functions, etc
int ScreenWidth = 640;  //screen width and height for SDL window
int ScreenHeight = 480; //
int main(int argc, char* argv[])
{
    SDL_Init(SDL_INIT_EVERYTHING);
    SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "1");
    SDL_Window* window = SDL_CreateWindow( "Game", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, ScreenWidth, ScreenHeight, SDL_WINDOW_SHOWN);
    SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    SDL_SetRenderDrawColor( renderer, 0xFF, 0xFF, 0xFF, 0xFF);  

    bool quit = false;
    SDL_Event event;
    while (!quit)
    {
        SDL_RenderClear(renderer);
        while (SDL_PollEvent(&event))
        {
            if (event.type == SDL_QUIT)
                quit = true;
        }
        SDL_Rect box;
        box.w = 30;
        box.h = 30;
        box.x = 50;
        box.y = 50;
        SDL_SetRenderDrawColor(renderer, 0xFF,0x00,0x00,0xFF);
        SDL_RenderFillRect(renderer, &box);
        SDL_RenderPresent(renderer);    
    }
    return 0; //because main is an int task
}