Switching Screens with LibGDX is Slow on Android Device

Question

The screen is loading perfectly fine in Desktop mode, but the screen freezes for about a second or two before loading the next one on my HTC One M8.

This is happening to all my screens, so I'll just show two. I tried loading all the assets for the next screen in the previous screen, and then checking to see if they are loaded using assets.update() before loading the next screen, but the freeze still occurs.

public class MenuScreen implements Screen, InputProcessor {
    private Application game;
    private OrthographicCamera cam;
    private Viewport viewport;

    private GameIcon gameIcon;
    private ParticleEffect effect;

    private MenuBackground mb, mb2;
    private Texture title_background, title, play_button, instructions_button, about_button, black_bottom;
    private Sprite titleSprite, playButtonSprite, instructionsButtonSprite, aboutButtonSprite, blackBottomSprite;
    private GameButton playBtn, instructionsBtn, aboutBtn;

    private static Music title_music;

    private long timeTouchUp;
    private boolean playUp, instructionsUp, aboutUp;

    private int touchX, touchY;

    private AssetManager assets; //loaded in SplashScreen

    public MenuScreen(Application game, AssetManager assets){
        this.game = game;

        Gdx.input.setInputProcessor(this);

        cam = new OrthographicCamera();
        cam.setToOrtho(false, Application.WIDTH, Application.HEIGHT);
        viewport = new FitViewport(Application.WIDTH, Application.HEIGHT, cam);

        this.assets = assets;
        queueAssets();

        title_background = assets.get("menu/title_background.png", Texture.class);
        title = assets.get("menu/title.png", Texture.class);
        play_button = assets.get("menu/play_button.png", Texture.class);
        instructions_button = assets.get("menu/instructions_button.png", Texture.class);
        about_button = assets.get("menu/about_button.png", Texture.class);
        black_bottom = assets.get("menu/black_bottom.png", Texture.class);


        titleSprite = new Sprite(title);
        playButtonSprite = new Sprite(play_button);
        instructionsButtonSprite = new Sprite(instructions_button);
        aboutButtonSprite = new Sprite(about_button);
        blackBottomSprite = new Sprite(black_bottom);

        playBtn = new GameButton();
        instructionsBtn = new GameButton();
        aboutBtn = new GameButton();

        mb = new MenuBackground(1);
        mb2 = new MenuBackground(2);

        title_music = assets.get("music/title_screen.mp3", Music.class);
        title_music.setLooping(true);
        title_music.play();

        gameIcon = new GameIcon(Application.WIDTH/2 - Application.WIDTH/10, Application.HEIGHT/10);

        effect = new ParticleEffect();
        effect.load(Gdx.files.internal("game/particles1.party"), Gdx.files.internal("game"));
        effect.start();

        timeTouchUp = 0;

        //setting things

        mb.getSprite().setX(0);
        mb2.getSprite().setX(0);

        blackBottomSprite.setSize(Application.WIDTH, Application.HEIGHT * 3 / 4);
        blackBottomSprite.setAlpha(1f);

        titleSprite.setSize(Application.WIDTH, Application.WIDTH * 0.5f); //width, height
        titleSprite.setPosition(Application.WIDTH / 2 - titleSprite.getWidth() / 2, Application.HEIGHT / 2 * 1.35f);

        playBtn.setTexture(play_button);
        playBtn.setOrigSize(titleSprite.getWidth() * 0.7f, titleSprite.getWidth() * 0.127f);
        playBtn.setOrigPosition(cam.position.x - playBtn.getWidth() / 2, cam.position.y + 80);

        instructionsBtn.setTexture(instructions_button);
        instructionsBtn.setOrigSize(titleSprite.getWidth() * 0.7f, titleSprite.getWidth() * 0.127f);
        instructionsBtn.setOrigPosition(cam.position.x - instructionsBtn.getWidth() / 2, cam.position.y + 10);

        aboutBtn.setTexture(about_button);
        aboutBtn.setOrigSize(titleSprite.getWidth() * 0.7f, titleSprite.getWidth() * 0.127f);
        aboutBtn.setOrigPosition(cam.position.x - aboutBtn.getWidth() / 2, cam.position.y - 60);

        gameIcon.setSize(50, 50);
        gameIcon.setPosition(Application.WIDTH / 2 - Application.WIDTH / 20, Application.HEIGHT / 10 + 10);
        gameIcon.setvX(0);
        gameIcon.setvY(0);
    }

    public void queueAssets() {
        assets.load("fonts/fixedsys.fnt", BitmapFont.class);
        assets.load("menu/black_bottom.png", Texture.class);
        assets.load("level_select/play_level.png", Texture.class);
    }

    @Override
    public void show() {

    }

    @Override
    public void render(float delta) {

        Gdx.gl.glClearColor(0, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        cam.update();

        game.batch.setProjectionMatrix(cam.combined);
        game.batch.begin();

        mb.update();
        mb2.update();
        mb.getSprite().setY(mb.getPosition().y);
        mb2.getSprite().setY(mb2.getPosition().y);

        mb.getSprite().draw(game.batch);
        mb2.getSprite().draw(game.batch);

        blackBottomSprite.draw(game.batch);

        titleSprite.draw(game.batch);

        playBtn.update();
        playBtn.draw(game.batch);

        instructionsBtn.update();
        instructionsBtn.draw(game.batch);

        aboutBtn.update();
        aboutBtn.draw(game.batch);

        gameIcon.draw(game.batch);

        effect.getEmitters().first().setPosition(Application.WIDTH / 2 - Application.WIDTH / 20 + gameIcon.getWidth() / 2, Application.HEIGHT / 10 + 10); //doesnt follow gameIcon
        effect.update(delta);
        effect.draw(game.batch);

        game.batch.end();

        gameIcon.update();

        if (TimeUtils.timeSinceMillis(timeTouchUp) > 100 && assets.update()) {
            if (playUp) {
                game.setScreen(new LevelSelectScreen(game, assets, mb.getSprite().getY(), mb2.getSprite().getY(), gameIcon));
                dispose();
            }
            else if(instructionsUp) {

            }
            else if(aboutUp) {

            }
        }

    }

    public static void stopMenuMusic()
    {
        title_music.stop();
        title_music.dispose();
    }

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

    @Override
    public void pause() {

    }

    @Override
    public void resume() {

    }

    @Override
    public void hide() {

    }

    @Override
    public void dispose() {
        title_background.dispose();
        title.dispose();
        play_button.dispose();
        instructions_button.dispose();
        about_button.dispose();
    }

    @Override
    public boolean keyDown(int keycode) {
        return true;
    }

    @Override
    public boolean keyUp(int keycode) {
        return true;
    }

    @Override
    public boolean keyTyped(char character) {
        return true;
    }

    @Override
    public boolean touchDown(int screenX, int screenY, int pointer, int button) {
        touchX = GameButton.convertX(screenX);
        touchY = GameButton.convertY(screenY);

        if(playBtn.checkCoords(touchX, touchY))
        {
            playBtn.clickDown();
        }
        else if(instructionsBtn.checkCoords(touchX, touchY))
        {
            instructionsBtn.clickDown();
        }
        else if(aboutBtn.checkCoords(touchX, touchY))
        {
            aboutBtn.clickDown();
        }

        return true;
    }

    @Override
    public boolean touchUp(int screenX, int screenY, int pointer, int button) {
        timeTouchUp = TimeUtils.millis();
        if (playBtn.checkCoords(touchX, touchY)) {
            playUp = true;
            playBtn.clickUp();
        }
        else if(instructionsBtn.checkCoords(touchX, touchY))
        {
            instructionsUp = true;
            instructionsBtn.clickUp();
        }
        else if(aboutBtn.checkCoords(touchX, touchY))
        {
            aboutUp = true;
            aboutBtn.clickUp();
        }

        return true;
    }

    @Override
    public boolean touchDragged(int screenX, int screenY, int pointer) {
        return true;
    }

    @Override
    public boolean mouseMoved(int screenX, int screenY) {
        return true;
    }

    @Override
    public boolean scrolled(int amount) {
        return true;
    }

    public boolean isClicked(Sprite sprite, float x, float y)
    {
        if (x >= sprite.getX() && x <= sprite.getX() + sprite.getWidth())
        {
            if (y >= sprite.getY() && y <= sprite.getY() + sprite.getHeight())
            {
                return true;
            }
        }
        return false;
    }
}

After clicking a button on the above screen, it should load this one:

public class LevelSelectScreen implements Screen, InputProcessor{

    private Application game;
    private OrthographicCamera cam;
    private Viewport viewport;

    private ParticleEffect effect;

    private Texture black_bottom, play_level_button;
    private Sprite blackBottomSprite;

    private String[] levelNames;

    private int maxLevel, level, touchX, touchY;
    private long timeTouchUp;

    private GameButton playLevelBtn;

    private GameIcon gameIcon;

    private MenuBackground mb, mb2;

    private boolean playUp;

    private BitmapFont font;
    public GlyphLayout levelLayout, levelNameLayout;

    private AssetManager assets; //loaded in MenuScreen

    public LevelSelectScreen(Application game, AssetManager assets, float mbY, float mb2Y, GameIcon gameIcon) {
        this.game = game;
        Gdx.input.setInputProcessor(this);

        this.assets = assets;
        queueAssets();

        levelNames = new String[2];
        levelNames[0] = "PLACEHOLDER";
        levelNames[1] = "Taking Off";
        maxLevel = levelNames.length - 1;
        level = 1;

        font = assets.get("fonts/fixedsys.fnt", BitmapFont.class);
        font.setColor(Color.BLACK);
        levelLayout = new GlyphLayout(font, "Level " + level);
        levelNameLayout = new GlyphLayout(font, levelNames[0]);

        cam = new OrthographicCamera();
        cam.setToOrtho(false, Application.WIDTH, Application.HEIGHT);
        viewport = new FitViewport(Application.WIDTH, Application.HEIGHT, cam);

        mb = new MenuBackground(mbY, true);
        mb2 = new MenuBackground(mb2Y, true);

        this.gameIcon = new GameIcon(Application.WIDTH / 2 - Application.WIDTH / 20, Application.HEIGHT / 10 + 10);

        black_bottom = assets.get("menu/black_bottom.png", Texture.class);
        play_level_button = assets.get("level_select/play_level.png", Texture.class);

        blackBottomSprite = new Sprite(black_bottom);

        //setting stuff
        mb.getSprite().setX(0);
        mb2.getSprite().setX(0);

        blackBottomSprite.setSize(Application.WIDTH, Application.HEIGHT * 3 / 4);
        blackBottomSprite.setAlpha(1f);

        this.gameIcon.setRotation(gameIcon.getRotation());
        this.gameIcon.setSize(gameIcon.getWidth(), gameIcon.getHeight());
        this.gameIcon.setvX(0);
        this.gameIcon.setvY(0);

        playLevelBtn = new GameButton();
        playLevelBtn.setTexture(play_level_button);
        playLevelBtn.setOrigSize(150, 90);
        playLevelBtn.setOrigPosition(
                Application.WIDTH / 2 - playLevelBtn.getWidth() / 2,
                this.gameIcon.getX() + this.gameIcon.getHeight() + 70);

        effect = new ParticleEffect();
        effect.load(Gdx.files.internal("game/particles1.party"), Gdx.files.internal("game"));
        effect.start();

        playUp = false;

    }

    public void queueAssets() {
        assets.load("game/backgrounds/shadow_mask.png", Texture.class);
        assets.load("game/backgrounds/background_orange.png", Texture.class);
        assets.load("game/border_left.png", Texture.class);
        assets.load("game/border_right.png", Texture.class);
        assets.load("game/backgrounds/white_only.png", Texture.class);
        assets.load("game/backgrounds/circles_pattern.png", Texture.class);
    }

    @Override
    public void show() {
    }

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

        cam.update();

        game.batch.setProjectionMatrix(cam.combined);
        game.batch.begin();

        mb.update();
        mb2.update();
        mb.getSprite().setY(mb.getPosition().y);
        mb2.getSprite().setY(mb2.getPosition().y);

        mb.getSprite().draw(game.batch);
        mb2.getSprite().draw(game.batch);
        blackBottomSprite.draw(game.batch);

        gameIcon.update();
        gameIcon.draw(game.batch);

        levelLayout.setText(font, "Level " + level);
        levelNameLayout.setText(font, levelNames[level]);
        font.draw(
                game.batch,
                "Level " + level,
                Application.WIDTH / 2 - levelLayout.width / 2,
                Application.HEIGHT / 2 + levelLayout.height / 2
        );

        effect.getEmitters().first().setPosition(Application.WIDTH / 2 - Application.WIDTH / 20 + gameIcon.getWidth() / 2, Application.HEIGHT / 10 + 10); //doesnt follow gameIcon
        effect.update(delta);
        effect.draw(game.batch);

        playLevelBtn.update();
        playLevelBtn.draw(game.batch);

        game.batch.end();

        if (TimeUtils.timeSinceMillis(timeTouchUp) > 100 && assets.update()) {
            if (playUp) {                game.setScreen(new com.xx4everPixelatedxx.gaterunner.screens.Levels.Level1Screen(game, assets));

                MenuScreen.stopMenuMusic();
                dispose();
            }
        }
    }

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

    @Override
    public void pause() {

    }

    @Override
    public void resume() {

    }

    @Override
    public void hide() {

    }

    @Override
    public void dispose() {

    }

    @Override
    public boolean keyDown(int keycode) {
        return false;
    }

    @Override
    public boolean keyUp(int keycode) {
        return false;
    }

    @Override
    public boolean keyTyped(char character) {
        return false;
    }

    @Override
    public boolean touchDown(int screenX, int screenY, int pointer, int button) {
        touchX = GameButton.convertX(screenX);
        touchY = GameButton.convertY(screenY);

        if(playLevelBtn.checkCoords(touchX, touchY))
        {
            playLevelBtn.clickDown();
        }

        return true;
    }

    @Override
    public boolean touchUp(int screenX, int screenY, int pointer, int button) {
        timeTouchUp = TimeUtils.millis();
        if (playLevelBtn.checkCoords(touchX, touchY)) {
            playUp = true;
            playLevelBtn.clickUp();
        }
        return true;
    }

    @Override
    public boolean touchDragged(int screenX, int screenY, int pointer) {
        return false;
    }

    @Override
    public boolean mouseMoved(int screenX, int screenY) {
        return false;
    }

    @Override
    public boolean scrolled(int amount) {
        return false;
    }
}

If you have not guessed it by now, my question is this: How can I make the screen to screen transition on my Android device take less time?

Answer 1

I am more than sure that your problem is in the loading resources. Please notice that although you are loading assets for LevelSelectScreen in MenuScreen you are still calling queueAssets(); in LevelSelect constructor.

Make a little test - remove all assets and ui elements using them and then check loading time.

First of all reduce count of loaded textures by packing them into TextureAtlas using TexturePacker. I/O operations are really expensive.

Secondly you can make the ResourcesManager (for example implementing Singleton) and keeping its static instance, loading all resources at the beggining of the application.