Why hide a window?

Hiding a window can be useful in a variety of situations. One common scenario is when you're working on applications that require temporary user distraction or focus management.

For example, a game launcher might hide the main application window while a settings dialog or a login screen is active, ensuring the user completes those actions before returning to the main window.

Similarly, background processes or utilities might use hidden windows to initialize resources without requiring immediate user interaction.

Another case is for applications where performance matters, and you want to delay rendering or event processing for windows that aren't visible. In SDL2, a hidden window won't be displayed on the screen, but you can still keep it in memory and manage its resources.

This allows for a seamless experience when you show the window again. Consider this example:

1#include <SDL.h>
2#include <iostream>
3
4int main() {
5  if (SDL_Init(SDL_INIT_VIDEO) != 0) {
6    std::cout << "SDL_Init Error: "
7      << SDL_GetError() << '\n';
8    return 1;
9  }
10
11  SDL_Window *window = SDL_CreateWindow(
12    "Example",
13    SDL_WINDOWPOS_CENTERED,
14    SDL_WINDOWPOS_CENTERED,
15    640, 480,
16    SDL_WINDOW_HIDDEN
17  );
18  if (!window) {
19    std::cout << "SDL_CreateWindow Error: "
20      << SDL_GetError() << '\n';
21    SDL_Quit();
22    return 1;
23  }
24
25  // Simulate some work
26  SDL_Delay(2000);
27
28  SDL_ShowWindow(window);  
29  SDL_Delay(2000);
30
31  SDL_DestroyWindow(window);
32  SDL_Quit();
33  return 0;
34}

1[No visible window for 2 seconds, then shown for 2 seconds]

This example creates a hidden window and only shows it after initialization. Using SDL_HideWindow() and SDL_ShowWindow(), you can toggle visibility dynamically, which is handy for use cases like splash screens or in-app tutorials.