First, we included the SDL.h header file so that we have access to all of SDL's functions:

#include<SDL.h>

The next step is to create some global variables. One is a pointer to an SDL_Window function, which will be set using the SDL_CreateWindow function. The second is a pointer to an SDL_Renderer object; set using the SDL_CreateRenderer function:

SDL_Window* g_pWindow = 0;
SDL_Renderer* g_pRenderer = 0;

We can now initialize SDL. This example initializes all of SDL's subsystems using the SDL_INIT_EVERYTHING flag, but this does not always have to be the case (see SDL initialization flags):

int main(int argc, char* argv[])
{
  // initialize SDL
  if(SDL_Init(SDL_INIT_EVERYTHING) >= 0)
   {

If the SDL initialization was successful, we can create the pointer to our window. SDL_CreateWindow returns a pointer to a window matching the passed parameters. The parameters are the window title, x position of the window, y position of the window, width, height, and any required SDL_flags (we will cover these later in the chapter). SDL_WINDOWPOS_CENTERED will center our window relative to the screen:

// if succeeded create our window
g_pWindow = SDL_CreateWindow("Chapter 1: Setting up SDL", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, SDL_WINDOW_SHOWN);

We can now check whether the window creation was successful, and if so, move on to set the pointer to our renderer, passing the window we want the renderer to use as a parameter; in our case, it is the newly created g_pWindow pointer. The second parameter passed is the index of the rendering driver to initialize; in this case, we use -1 to use the first capable driver. The final parameter is SDL_RendererFlag (see SDL renderer flags):

// if the window creation succeeded create our renderer
if(g_pWindow != 0)
{
  g_pRenderer = SDL_CreateRenderer(g_pWindow, -1, 0);
}
else
{
  return 1; // sdl could not initialize
}

If everything was successful, we can now create and show our window:

// everything succeeded lets draw the window

  // set to black
SDL_SetRenderDrawColor(g_pRenderer, 0, 0, 0, 255);

   // clear the window to black
SDL_RenderClear(g_pRenderer);

   // show the window
SDL_RenderPresent(g_pRenderer);

   // set a delay before quitting
SDL_Delay(5000);

   // clean up SDL
SDL_Quit();