Can I remove only the title bar?

SDL2 does not natively support removing only the title bar while keeping the borders. When you use the SDL_WINDOW_BORDERLESS flag, all decorations, including the title bar and borders, are removed.

If you need this functionality, you'll need to use platform-specific APIs to modify the window style directly. For example, on Windows, you could use the Win32 API to customize the WS_BORDER and WS_CAPTION flags of the window.

However, this approach bypasses SDL2's abstraction and ties your code to a specific platform.

Here's an example of creating a completely borderless window in SDL2 (no title bar or borders):

1#include <SDL.h>
2
3int main() {
4  SDL_Init(SDL_INIT_VIDEO);
5
6  SDL_Window* Window{SDL_CreateWindow(
7    "No Title Bar",
8    SDL_WINDOWPOS_CENTERED,
9    SDL_WINDOWPOS_CENTERED,
10    800, 600,
11    SDL_WINDOW_BORDERLESS 
12  )};
13
14  SDL_Delay(3000);
15  SDL_DestroyWindow(Window);
16  SDL_Quit();
17}

To keep the borders but remove the title bar, a workaround is to simulate borders using custom rendering inside the client area. Alternatively, look into platform-specific APIs if this functionality is critical.