FlappyTurtle/GameScreen.java

import java.awt.Color;
import java.util.List;
import java.util.ArrayList;

class GameScreen implements LinearColorAnimator.AnimationListener
{
    private static class Level
    {
        public Color birdColor;
        public Color obstacleColor;
        public Color backgroundColor;

        public Level(Color bird, Color obst, Color bg)
        {
            birdColor = bird;
            obstacleColor = obst;
            backgroundColor = bg;
        }
    }

    private final static ArrayList<Level> LEVELS = new ArrayList<Level>();
    static
    {
        LEVELS.add(new Level(Color.CYAN, Color.BLACK, Color.WHITE));
        LEVELS.add(new Level(Color.WHITE, Color.WHITE, Color.BLACK));
        LEVELS.add(new Level(Color.ORANGE, Color.ORANGE, Color.RED));
        LEVELS.add(new Level(Color.CYAN, Color.CYAN, Color.BLACK));
    };
    // Time in seconds until new level is reached
    // You might wanna set that to 3 or so to enjoy more rapid color changes
    private final static int LEVEL_TIME = 10;

    private final List<Drawable> _drawables;
    private final Bird _bird;
    private final World _world;
    private final LinearColorAnimator _backgroundAnimator, _birdAnimator, _obstacleAnimator;
    private double _totalTime;
    private int _try;
    private int _level;

    public GameScreen()
    {
        _drawables = new ArrayList<Drawable>();
        _backgroundAnimator = new LinearColorAnimator(Color.BLACK, LEVELS.get(0).backgroundColor, 1, this);
        _birdAnimator = new LinearColorAnimator(LEVELS.get(0).birdColor, LEVELS.get(0).birdColor, 1, this);
        _obstacleAnimator = new LinearColorAnimator(LEVELS.get(0).obstacleColor, LEVELS.get(0).obstacleColor, 1, this);
        _backgroundAnimator.start();
        _bird = new Bird(this, LEVELS.get(0).birdColor);
        _world = new World(this);
        _world.setObstacleColor(LEVELS.get(0).obstacleColor);
        _totalTime = 0;
        _try = 1;
    }

    private void animateBack(LinearColorAnimator animator, Color target)
    {
        if (animator.getCurrentColor().getRGB() != target.getRGB())
        {
            animator.setStart(animator.getCurrentColor());
            animator.setEnd(target);
            animator.start();
        }
    }

    /*
     * Elapsed time is expected to be in ms
     */
    public void update(double elapsed)
    {
        _bird.update(elapsed);
        _world.update(elapsed);
        _backgroundAnimator.update(elapsed);
        _birdAnimator.update(elapsed);
        _obstacleAnimator.update(elapsed);
        _totalTime += elapsed;
        System.out.print("\r" + _try + " - Time survived: " + (int)(_totalTime * 1e-3) + "s, " +
                "speed: " + (int)_world.getSpeed() + "px/s");

        if (_totalTime / (LEVEL_TIME * 1e3) > _level + 1)
        {
            ++_level;
            if (_level < LEVELS.size())
            {
                _backgroundAnimator.setStart(LEVELS.get(_level-1).backgroundColor);
                _backgroundAnimator.setEnd(LEVELS.get(_level).backgroundColor);
                _backgroundAnimator.start();
                _birdAnimator.setStart(LEVELS.get(_level-1).birdColor);
                _birdAnimator.setEnd(LEVELS.get(_level).birdColor);
                _birdAnimator.start();
                _obstacleAnimator.setStart(LEVELS.get(_level-1).obstacleColor);
                _obstacleAnimator.setEnd(LEVELS.get(_level).obstacleColor);
                _obstacleAnimator.start();
            }
        }

        Rectangle birdRect = _bird.getRect();
        if (_world.checkCollision(_bird.getRect())
                || birdRect.getY() > TurtleWelt.HEIGHT
                || birdRect.getY() + birdRect.getHeight() < 0)
        {
            System.out.print("\n");
            ++_try;
            _totalTime = _level = 0;
            _bird.reset();
            _world.reset();
            _bird.setColor(LEVELS.get(0).birdColor);

            // If the background is currently not white, smoothly animate it back
            animateBack(_backgroundAnimator, LEVELS.get(0).backgroundColor);
            animateBack(_birdAnimator, LEVELS.get(0).birdColor);
            animateBack(_obstacleAnimator, LEVELS.get(0).obstacleColor);
        }
    }

    public void onAnimationFinished() {}

    public void draw(Turtle turtle, double elapsed)
    {
        Color bg = _backgroundAnimator.getCurrentColor();
        TurtleWelt.globaleWelt.bildschirmEinfaerben(bg.getRed(), bg.getGreen(), bg.getBlue());

        if (!_birdAnimator.hasFinished())
        {
            _bird.setColor(_birdAnimator.getCurrentColor());
        }
        if (!_obstacleAnimator.hasFinished())
        {
            _world.setObstacleColor(_obstacleAnimator.getCurrentColor());
        }
        for (Drawable d : _drawables)
        {
            d.draw(turtle, elapsed);
        }
    }

    public void addDrawable(Drawable d)
    {
        _drawables.add(d);
    }

    public void jump()
    {
        _bird.jump();
    }
}