void GameMenu::Initialize()
{
    // MAIN MENU
    Tween* mainMenu = tweening.AddItem(new Tween(nullptr));
    Tween* subCampaign = tweening.AddItem(new SubMenu(mainMenu, "Campaign", D3DXVECTOR3(75, 250, 0)));
    Tween* subMultiplayer = tweening.AddItem(new SubMenu(subCampaign, "Multiplayer"));
    Tween* subExtras = tweening.AddItem(new SubMenu(subMultiplayer, "Extras"));
    Tween* subOptions = tweening.AddItem(new SubMenu(subExtras, "Options"));
    Tween* subQuit = tweening.AddItem(new SubMenu(subOptions, "Quit Game"));

    // CAMPAIGN MENU
    Tween* menuCampaign = tweening.AddItem(new SubMenuSeparator(subCampaign));
    Tween* subSingle = tweening.AddItem(new SubMenu(menuCampaign, "Single Player"));
    Tween* subCoop = tweening.AddItem(new SubMenu(subSingle, "Co-op"));

    // SINGLE PLAYER MENU
    Tween* menuSinglePlayer = tweening.AddItem(new SubMenuSeparator(subSingle));
    Tween* labelSingleDifficulty = tweening.AddItem(new MenuLabel(menuSinglePlayer, "Difficulty:", D3DXVECTOR3(0, 32, 0)));
    Tween* buttonSingleHard = tweening.AddItem(new MenuButton(labelSingleDifficulty, "Hard", D3DXVECTOR3(0, 32, 0), [](){ MessageBox(Dx9::GetWindow(), "Hard!", "Single Player", MB_OK); }));
    Tween* buttonSingleMedium = tweening.AddItem(new MenuButton(buttonSingleHard, "Medium", D3DXVECTOR3(0, 32, 0), [](){ MessageBox(Dx9::GetWindow(), "Medium!", "Single Player", MB_OK); }));
    Tween* buttonSingleEasy = tweening.AddItem(new MenuButton(buttonSingleMedium, "Easy", D3DXVECTOR3(0, 32, 0), [](){ MessageBox(Dx9::GetWindow(), "Easy!", "Single Player", MB_OK); }));

    // CO-OP MENU
    Tween* menuCoop = tweening.AddItem(new SubMenuSeparator(subCoop));
    Tween* labelCoopDifficulty = tweening.AddItem(new MenuLabel(menuCoop, "Difficulty:", D3DXVECTOR3(0, 32, 0)));
    Tween* buttonCoopHard = tweening.AddItem(new MenuButton(labelCoopDifficulty, "Hard", D3DXVECTOR3(0, 32, 0), [](){ MessageBox(Dx9::GetWindow(), "Hard!", "Co-op", MB_OK); }));
    Tween* buttonCoopMedium = tweening.AddItem(new MenuButton(buttonCoopHard, "Medium", D3DXVECTOR3(0, 32, 0), [](){ MessageBox(Dx9::GetWindow(), "Medium!", "Co-op", MB_OK); }));
    Tween* buttonCoopEasy = tweening.AddItem(new MenuButton(buttonCoopMedium, "Easy", D3DXVECTOR3(0, 32, 0), [](){ Game::ChangeState(new GameWorld()); }));

    // MULTIPLAYER MENU
    Tween* menuMultiplayer = tweening.AddItem(new SubMenuSeparator(subMultiplayer));
    Tween* subNetwork = tweening.AddItem(new SubMenu(menuMultiplayer, "Network"));
    Tween* subLan = tweening.AddItem(new SubMenu(subNetwork, "LAN"));

    // OPTIONS MENU
    Tween* menuOptions = tweening.AddItem(new SubMenuSeparator(subOptions));
    Tween* subVideo = tweening.AddItem(new SubMenu(menuOptions, "Video Settings"));
    Tween* subAudio = tweening.AddItem(new SubMenu(subVideo, "Audio Settings"));

    // VIDEO SETTINGS MENU
    Tween* menuVideo = tweening.AddItem(new SubMenuSeparator(subVideo));
    Tween* checkFullscreen = tweening.AddItem(new CheckBox(menuVideo, "Fullscreen", D3DXVECTOR3(0, 32, 0), &fullscreen));
    Tween* checkVSync = tweening.AddItem(new CheckBox(checkFullscreen, "V-Sync", D3DXVECTOR3(0, 32, 0), &vsync));

    // AUDIO SETTINGS MENU
    Tween* menuAudio = tweening.AddItem(new SubMenuSeparator(subAudio));
    Tween* labelVolume = tweening.AddItem(new MenuLabel(menuAudio, "Volume:", D3DXVECTOR3(0, 32, 0)));
    Tween* sliderMaster = tweening.AddItem(new MenuSlider(labelVolume, "Master", D3DXVECTOR3(0, 32, 0), &volumeMaster));
    Tween* sliderMusic = tweening.AddItem(new MenuSlider(sliderMaster, "Music", D3DXVECTOR3(0, 32, 0), &volumeMusic));
    Tween* sliderEffects = tweening.AddItem(new MenuSlider(sliderMusic, "Effects", D3DXVECTOR3(0, 32, 0), &volumeEffects));

    // QUIT MENU
    Tween* menuQuit = tweening.AddItem(new SubMenuSeparator(subQuit));
    Tween* labelConfirm = tweening.AddItem(new MenuLabel(menuQuit, "Are you sure?", D3DXVECTOR3(0, 32, 0)));
    Tween* buttonQuit = tweening.AddItem(new MenuButton(labelConfirm, "Absolutely", D3DXVECTOR3(0, 32, 0), [](){ PostQuitMessage(0); }));
    Tween* buttonNevermind = tweening.AddItem(new MenuButton(buttonQuit, "Nevermind", D3DXVECTOR3(0, 32, 0), [subQuit](){ ((SubMenu*)subQuit)->Collapse(); }));
}