Libgdx Viewport example

public class Main extends Game {
    public static final int V_WIDTH = 1920;
    public static final int V_HEIGHT = 1080;

    OrthographicCamera cam;
    Stage stage;

        TextureAtlas atlas;
    Image Logo;

    @Override
    public void create () {
        cam = new OrthographicCamera();
        cam.setToOrtho(false, 800, 600);

        stage = new Stage(new FitViewport(V_WIDTH, V_HEIGHT, cam));

        atlas = new TextureAtlas("LoadingScreen.pack");
        Logo = new Image(atlas.findRegion("VeslaLogo"));

        Logo.setX(stage.getWidth() / 2 - Logo.getWidth() / 2);
        Logo.setY(stage.getHeight() / 2 - Logo.getHeight() / 2);
        stage.addActor(Logo);
    }

    @Override
    public void resize(int width, int height) {
        stage.getViewport().update(width, height, false);
    }

    @Override
    public void render () {
        Gdx.gl.glClearColor(1, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        stage.act();
        stage.draw();
    }

    @Override
    public void dispose() {
        atlas.dispose();
        stage.dispose();
    }
}