How can I split my entity manager class into a gameworld class and gamerenderer class?

Question

I currently have a libGDX game where I have an entity manager class which is called in the gamescreen. Instead, I would like to utilise it in a gameworld class and a gamerenderer class, but I cannot figure out how to split it up (if that makes sense). I want to do this so that I can manipulate my player class separately and not as a part of the entity manager. Previous attempts have failed because taking 'player' away meant that checkCollisions stopped working (hence why I want to use gameworld and gamerenderer classes instead). Does anyone have any ideas on how to achieve this?

Here is my entity manager class:

public class EntityManager {
    private final Array<Entity> entities = new Array<Entity>();
    private final Player player;

    public EntityManager(int amount) {
        player = new Player(new Vector2(110, 15), new Vector2(0, 35));
        for (int i = 0; i < amount; i++) {
            float x = MathUtils.random(0, ManicMeltdowns.WIDTH - TextureManager.DROPS.getWidth());
            float y = MathUtils.random(ManicMeltdowns.HEIGHT, ManicMeltdowns.HEIGHT * 3);
            float speed = 2;
            addEntity(new Drops(new Vector2 (x, y), new Vector2(0, -speed)));
        }
    }

    public void update() {
        for (Entity e : entities)
            e.update();
        player.update();
        checkCollisions();
    }

    public void render(SpriteBatch sb) {
        for (Entity e : entities)
            e.render(sb);
        player.render(sb);
    }

    private void checkCollisions() {
        for (Drops e : getDrops()) {
            if (e.getBounds().overlaps(player.rectangle)) {
                ScreenManager.setScreen(new GameOverScreen());
            }
        }
    }

    public void addEntity(Entity entity) {
        entities.add(entity);
    }

    private Array<Drops> getDrops() {
        Array<Drops> ret = new Array<Drops>();
        for (Entity e : entities)
            if (e instanceof Drops)
                ret.add((Drops)e);
        return ret;
    }
}

Thanks.

Answer 1

I'm no too sure of the overall design of your game, but I don't see why you would need GameWorld or GameRenderer classes since Screens generally accomplish such tasks.

To separate the player and keep collision detection you can simply require the instance as an argument:

private void checkCollisions(Player player) {
    for (Drops e : getDrops()) {
        if (e.getBounds().overlaps(player.rectangle)) {
            ScreenManager.setScreen(new GameOverScreen());
        }
    }
}