LinkedList爲什麼不通過所有的實體？

Question

我正在嘗試開發碰撞檢測。出於某種原因，碰撞正在爲LinkedList中的最後一個實體工作。我盡力用控制檯調試它，看看它停止了，但我沒有運氣。所有其他實體都不工作，只有最後一個實體。下面是代碼：

public class Player implements Entity { 

Image player; 

public float x = 100f; 
public float y = 100f; 

boolean canGoLeft = true; 
boolean canGoRight = true; 
boolean canGoUp = true; 
boolean canGoDown = true; 

public float speed = 0.15f; 

public Rectangle leftRect; 
public Rectangle rightRect; 
public Rectangle topRect; 
public Rectangle bottomRect; 

int i = 0; 

Entities entities = new Entities(); 

public Player() { 

} 

public void update(GameContainer game, int delta) { 

    if(Keyboard.isKeyDown(Keyboard.KEY_D)) { 
     if(canGoRight) { 
      x += speed * delta; 
     } 
    } 

    if(Keyboard.isKeyDown(Keyboard.KEY_A)) { 
     if(canGoLeft) { 
      x -= speed * delta; 
     } 
    } 

    if(Keyboard.isKeyDown(Keyboard.KEY_W)) { 
     if(canGoUp) { 
      y -= speed * delta; 
     } 
    } 

    if(Keyboard.isKeyDown(Keyboard.KEY_S)) { 
     if(canGoDown) { 
      y += speed * delta; 
     } 
    } 

    for(Entity entity : Game.entities.entities) { 
     checkCollisions(entity); 
    } 

} 

public void render(GameContainer game, Graphics g) { 

    leftRect = new Rectangle(x, y + 5, 2, 80); 
    rightRect = new Rectangle(x + 45, y + 5, 2, 80); 
    topRect = new Rectangle(x + 6, y, 36, 2); 
    bottomRect = new Rectangle(x + 6, y + 90, 36, 2); 

    //rect = new Rectangle(200, 100, 60, 88); 

    try { 
     player = new Image("res/Player.png"); 
     player.setFilter(Image.FILTER_NEAREST); 
    } catch (SlickException e) { 
     e.printStackTrace(); 
    } 


    player.draw(x, y, 60, 88); 

    //g.draw(leftRect); 
    //g.draw(rightRect); 
    //g.draw(topRect); 
    //g.draw(bottomRect); 

} 

public void checkCollisions(Entity entity) { 

    // Collision Detection 

    canGoLeft = !leftRect.intersects(entity.getRect()); 
    canGoRight = !rightRect.intersects(entity.getRect()); 
    canGoDown = !bottomRect.intersects(entity.getRect()); 
    canGoUp = !topRect.intersects(entity.getRect()); 

} 

public Rectangle getRect() { 
    return null; 
} 

} 

Answer 1

這是通過你的整個列表進行迭代，但checkCollisions覆蓋每次調用時canGoLeft，canGoRright等的價值。

你應該這樣做

canGoLeft = canGoLeft && !leftRect.intersects(entity.getRect());