はcom.gamesでLibGDX

Question

public class PlayState extends State { 

private static final int TUBE_SPACING = 125; 
private static final int TUBE_COUNT = 4; 
private static final int GROUND_Y_OFFSET = -30; 
private static final int COIN_SPACING = 100; 
private static final int COIN_COUNT = 2; 


public int SCORE = 0; 

private Bird bird; 
private Coin coin; 

private Texture bg; 
private Texture ground; 
private Vector2 groundPos1, groundPos2; 

private Array<Tube> tubes; 

private Array<Coin> coins; 

public PlayState(GameStateManager gsm) { 
    super(gsm); 
    bird = new Bird(50, 300); 

    cam.setToOrtho(false, FlappyDemo.WIDTH/2, FlappyDemo.HEIGHT/2); 
    bg = new Texture("bg.png"); 
    ground = new Texture("ground.png"); 
    groundPos1 = new Vector2(cam.position.x - cam.viewportWidth/2, GROUND_Y_OFFSET); 
    groundPos2 = new Vector2((cam.position.x - cam.viewportWidth/2) + ground.getWidth(), GROUND_Y_OFFSET); 

    tubes = new Array<Tube>(); 

    for(int i = 1; i <= TUBE_COUNT; i++){ 
     tubes.add(new Tube(i * (TUBE_SPACING + Tube.TUBE_WIDTH))); 
    } 

    coins = new Array<Coin>(); 
    for(int i = 1; i<= COIN_COUNT; i++){ 
     coins.add(new Coin(i * (COIN_SPACING + (Coin.COIN_WIDTH/3)))); 
    } 

} 

@Override 
protected void handleInput() { 
    if(Gdx.input.justTouched()){ 
     bird.jump(); 
    } 
} 

@Override 
public void update(float dt) { 
    handleInput(); 
    updateGround(); 
    bird.update(dt); 
    coin.update(dt); 
    cam.position.x = bird.getPosition().x +80; 
    updateCoin(); 
    updateTube(); 

    if(bird.getPosition().y <= ground.getHeight() + GROUND_Y_OFFSET){ 
     gsm.set(new MenuState(gsm)); 
     System.out.println("Score : "+SCORE); 
    } 
    cam.update(); 
} 

@Override 
public void render(SpriteBatch sb) { 
    sb.setProjectionMatrix(cam.combined); 
    sb.begin(); 
    sb.draw(bg, cam.position.x - (cam.viewportWidth/2), 0); 
    sb.draw(bird.getTexture(), bird.getPosition().x, bird.getPosition().y); 
    for(Tube tube : tubes) { 
     sb.draw(tube.getTopTube(), tube.getPosTopTube().x, tube.getPosTopTube().y); 
     sb.draw(tube.getBottomTube(), tube.getPosBotTube().x, tube.getPosBotTube().y); 
    } 
    for(Coin coin : coins){ 
     sb.draw(coin.getTexture(), coin.getPosCoin().x, coin.getPosCoin().y); 
    } 
    sb.draw(ground, groundPos1.x, groundPos1.y); 
    sb.draw(ground, groundPos2.x, groundPos2.y); 
    sb.end(); 
} 

@Override 
public void dispose() { 
    bg.dispose(); 
    bird.dispose(); 
    ground.dispose(); 
    for(Tube tube : tubes) 
     tube.dispose(); 
    for(Coin coin : coins) 
     coin.dispose(); 
    System.out.println("PlayState disposed"); 
} 

private void updateGround(){ 
    if(cam.position.x - (cam.viewportWidth/2) > groundPos1.x + ground.getWidth()) 
     groundPos1.add(ground.getWidth() * 2, 0); 
    if(cam.position.x - (cam.viewportWidth/2) > groundPos2.x + ground.getWidth()) 
     groundPos2.add(ground.getWidth() * 2, 0); 
} 

private void updateTube(){ 
    for(int i = 0; i< tubes.size; i++){ 
     Tube tube = tubes.get(i); 

     if(cam.position.x - (cam.viewportWidth/2) > tube.getPosTopTube().x + tube.getTopTube().getWidth()){ 
      tube.reposition(tube.getPosTopTube().x + ((Tube.TUBE_WIDTH + TUBE_SPACING) * TUBE_COUNT)); 
     } 
     if(tube.collides(bird.getBounds())){ 
      gsm.set(new MenuState(gsm)); 
      System.out.println("Score : "+SCORE); 
     } 
    } 
} 

private void updateCoin(){ 
    for(int i = 0; i< coins.size; i++){ 
     Coin coin = coins.get(i); 

     if(cam.position.x - (cam.viewportWidth/2) > coin.getPosCoin().x + coin.getTexCoin().getWidth()){ 
      coin.reposition(coin.getPosCoin().x + ((Coin.COIN_WIDTH + COIN_SPACING) * COIN_COUNT)); 
     } 
     if(coin.collides(bird.getBounds())){ 
      SCORE = SCORE + 10; 
      System.out.println("Collided"); 
     } 
    } 
} 

}スレッド内

public class Coin { 

public static final int COIN_WIDTH = 32; 
public static final int COIN_HEIGHT = 32; 
public static final int COIN_SCORE = 10; 
private static final int FLUCTUATION = 150; 
private static final int COIN_GAP = 100; 

private Texture texCoin; 
private Vector2 posCoin; 
private Rectangle boundsCoin; 
private Random randCoin; 
private Animation coinAnimation; 


public Coin(int x){ 
    texCoin = new Texture("Coin.png"); 
    randCoin = new Random(); 

    posCoin = new Vector2(x, randCoin.nextInt(Tube.TUBE_GAP) + COIN_GAP); 
    coinAnimation = new Animation(new TextureRegion(texCoin), 3, 0.5f); 
    boundsCoin = new Rectangle(x, posCoin.y, texCoin.getWidth()/3, texCoin.getHeight()); 
} 

public void update(float dt){ 
    try{ 
     coinAnimation.update(dt); 
     posCoin.set(randCoin.nextInt(FLUCTUATION) + COIN_GAP, randCoin.nextInt(FLUCTUATION)+ Tube.TUBE_GAP); 
     boundsCoin.setPosition(posCoin.x, posCoin.y); 
    }catch(Exception e){ 
     System.out.println("Errrrrr!"); 
    } 
} 

public Texture getTexCoin() { return texCoin;} 

public Vector2 getPosCoin() { return posCoin;} 

public TextureRegion getTexture() { 
    return coinAnimation.getFrame(); 
} 

public void reposition(float x){ 
    posCoin.set(x, randCoin.nextInt(FLUCTUATION) + COIN_GAP); 
    boundsCoin.setPosition(posCoin.x, posCoin.y); 
} 

public boolean collides(Rectangle coinBound){ 
    return coinBound.overlaps(boundsCoin); 
} 

public void dispose(){ 
    texCoin.dispose(); 
} 

}

例外 "LWJGLアプリケーション" java.lang.NullPointerExceptionが を使用してゆるい鳥アンドロイドゲームでコインをアニメーション化しようとしています.flappy.statess.PlayState.update（PlayState.java:75） com.games.flappy.statess.GameStateManager.update（GameStateManager.java:31） com.games.flappy.FlappyDemo.render（FlappyD emo.java:37） at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop（LwjglApplication.java:223） at com.badlogic.gdx.backends.lwjgl.LwjglApplication $ 1.run（LwjglApplication.java:124） ）

Answer 1

それは上に吹いている：

coin.update(dt); 

あなたはコインの変数を持っていますが、あなたが実際にそれに何かを割り当てるようにしていません。あなたのコードの残りはもちろん、多くの個々のコインオブジェクトを含むコインアレイ上で動作します。しかし、私はコイン変数が何かを参照するとは思わない？