screen resolution API

matthewg42 · 10-27-2007, 04:02 AM

I have a QT-based app which has a full screen mode feature. QT's full screen feature works by resizing the application window to the size of the desktop (the virtual desktop if you are using one), and removing window borders. It's OK, but I'd really like a mechanism to be able to switch to other screen resolutions as well.

Does anyone know of an API which will let me:

Get a list of available resolutions
Switch to a new resolution
The kicker: Is cross platform (win/osx/linux/other *nix)

It's the last criteria which is the real killer. The app used to use SDL for the main application window (and as such used to have this functionality), but I would very much like to drop the dependency to SDL and instead use a much smaller library which just does screen resolution switching. SDL is also somewhat unsuitable because it can only switch between full screen and windowed mode at start time on OSX and Windows, and I would like to be able to make this switch at any time.

dmail · 10-27-2007, 08:18 AM

Quote:

SDL is also somewhat unsuitable because it can only switch between full screen and windowed mode at start time on OSX and Windows, and I would like to be able to make this switch at any time.

This is true as the SDL_WM_ToggleFullScreen does not work on these os's yet it is really easy to implement your own by tearing it down and rebuilding it.

Code:

// Toggles the window between full-screen and not
void Sdl_window::toggle_fullscreen()
{
	m_fullscreen = !m_fullscreen;

	if(! ( SDL_WM_ToggleFullScreen( m_surface ) )  )//doesnt work on windows.
	{   
		//that failed so lets try in code ourselves
		if( m_fullscreen )
		{
			m_video_flags |= SDL_FULLSCREEN;//or the bit mask
			//reset the videomode
			m_surface = SDL_SetVideoMode( m_full_w, m_full_h, m_bpp, m_video_flags );
		}
		else
		{	
			m_video_flags &= ~SDL_FULLSCREEN;//remove the bit mask
			//reset the videomode
			m_surface = SDL_SetVideoMode( m_rect.w, m_rect.h, m_bpp, m_video_flags );
		}

		if(!m_surface)//failed to get a surface
		{
			throw std::runtime_error(std::string("SDL Set Video mode failed. error: ") + SDL_GetError() );
		}
	}

}