Toggle Fullscreen at Runtime

Question

Using the library GLFW, I can create a fullscreen window using this line of code.

glfwOpenWindow(Width, Height, 8, 8, 8, 8, 24, 0, GLFW_FULLSCREEN);

The line for creating a standard window looks like this.

glfwOpenWindow(Width, Height, 8, 8, 8, 8, 24, 0, GLFW_WINDOW);

What I want to do is letting the user switch between standard window and fullscreen by a keypress, let's say F11.

It there a common practice of toggling fullscreen mode? What do I have to consider?

Answer 1

I'm not sure about common practices, but lacking a glfwToggleFullscreen, this seems one way to toggle fullscreen mode:

// On input handling, check if F11 is down.
if ( glfwGetKey( GLFW_KEY_F11 ) ) {

    // Toggle fullscreen flag.
    fullscreen = !fullscreen;

    // Close the current window.
    glfwCloseWindow();

    // Renew calls to glfwOpenWindowHint.
    // (Hints get reset after the call to glfwOpenWindow.)
    myGLFWOpenWindowHints();

    // Create the new window.
    glfwOpenWindow(Width, Height, 8, 8, 8, 8, 24, 0,
                   fullscreen ? GLFW_FULLSCREEN : GLFW_WINDOW);

}

Another method, this time for fullscreen windowed mode:

// Create your window in windowed mode.
glfwOpenWindow(originalWidth, originalHeight, 8, 8, 8, 8, 24, 0, GLFW_WINDOW);
glfwSetWindowPos(originalPosX, originalPosY);

// Get the desktop resolution.
GLFWvidmode desktopMode;
glfwGetDesktopMode(&desktopMode);
desktopHeight = desktopMode.Height;
desktopWidth = desktopMode.Width;

// --8<--

// On input handling, check if F11 is down.
if ( glfwGetKey( GLFW_KEY_F11 ) ) {
    // Toggle fullscreen flag.
    fullscreen = !fullscreen;

    if ( fullscreen ) {
        // Set window size for "fullscreen windowed" mode to the desktop resolution.
        glfwSetWindowSize(desktopWidth, desktopHeight);
        // Move window to the upper left corner.
        glfwSetWindowPos(0, 0);
    } else {
        // Use start-up values for "windowed" mode.
        glfwSetWindowSize(originalWidth, originalHeight);
        glfwSetWindowPos(originalPosX, originalPosY);            
    }
}

Answer 2

I'd suggest looking at the implementation of SFML, which fluently switches between fullscreen and windowed on Windows, Mac and Linux. SFAIK it doesn't use GLFW, but perhaps similar principles apply.