SDL Example C++

sdl-example.cpp

/// Simple DirectMedia Layer Example
/// If everything is correctly installed, you should see a black window
/// which is gradually filled with white, starting from the top.
#include <SDL2/SDL.h>

int main() {
  auto sdl_init_result = SDL_Init(SDL_INIT_VIDEO);

  if (sdl_init_result != 0) {
    return 1;
  }

  int width = 640;
  int height = 480;

  auto win = SDL_CreateWindow("Example",               //
                              SDL_WINDOWPOS_UNDEFINED, //
                              SDL_WINDOWPOS_UNDEFINED, //
                              width,                   //
                              height,                  //
                              SDL_WINDOW_SHOWN         //
  );

  if (win == nullptr) {
    return 2;
  }

  auto surface = SDL_GetWindowSurface(win);
  auto pixels = static_cast<int*>(surface->pixels);

  /// Start from the top
  int line = 0;

  bool running = true;

  while (running) {
    /// Check if quit event is triggered
    {
      SDL_Delay(40);
      SDL_Event event;
      if (SDL_PollEvent(&event) == 1) {
        if (event.type == SDL_QUIT) {
          running = false;
        }
      }
    }

    /// Draw the line
    for (int y = 0; y < width; ++y) {
      pixels[line * width + y] = 0x00FFFFFF;
    }

    line += 1;

    /// Exit when full
    if (line == height) {
      running = false;
    }

    SDL_UpdateWindowSurface(win);
  }

  SDL_DestroyWindow(win);
  SDL_Quit();

  return 0;
}