Creating a Fullscreen Window with SDL2

To create a fullscreen window with SDL2, you can use the SDL_WINDOW_FULLSCREEN flag when creating your window. Here's an example:

1#include <SDL.h>
2
3int main(int argc, char** argv) {
4  SDL_Window* window{SDL_CreateWindow(
5    "Fullscreen Example",
6    SDL_WINDOWPOS_CENTERED,
7    SDL_WINDOWPOS_CENTERED,
8    0, 0,
9    SDL_WINDOW_FULLSCREEN 
10  )};
11
12  // ...
13
14  SDL_DestroyWindow(window);
15  SDL_Quit();
16
17  return 0;
18}

When using SDL_WINDOW_FULLSCREEN, you should set the window's width and height to 0, as SDL will automatically use the resolution of the fullscreen display.

You can also use SDL_WINDOW_FULLSCREEN_DESKTOP instead, which will create a borderless window that covers the entire screen without changing the display resolution.

To toggle between windowed and fullscreen modes at runtime, you can use SDL_SetWindowFullscreen:

1Uint32 flags = SDL_GetWindowFlags(window);
2if (flags & SDL_WINDOW_FULLSCREEN) {
3  SDL_SetWindowFullscreen(window, 0);
4} else {
5  SDL_SetWindowFullscreen(
6    window, SDL_WINDOW_FULLSCREEN);
7}

This will switch the window between fullscreen and windowed modes when called.