给我一个使用四叉树优化cocos贪吃蛇大作战食物的碰撞检测的js代码

以下是使用四叉树优化碰撞检测的示例代码：

// 定义四叉树节点类
class QuadTreeNode {
  constructor(x, y, width, height, maxObjects, maxLevels, level) {
    this.x = x; // 节点左上角的 x 坐标
    this.y = y; // 节点左上角的 y 坐标
    this.width = width; // 节点的宽度
    this.height = height; // 节点的高度
    this.maxObjects = maxObjects; // 节点最多存储的对象数
    this.maxLevels = maxLevels; // 四叉树最大深度
    this.level = level; // 节点深度
    this.objects = []; // 存储在节点中的所有对象
    this.nodes = []; // 存储子节点
  }

  // 分裂节点，将节点分成四个子节点
  split() {
    const subWidth = this.width / 2;
    const subHeight = this.height / 2;
    const x = this.x;
    const y = this.y;

    this.nodes[0] = new QuadTreeNode(x + subWidth, y, subWidth, subHeight, this.maxObjects, this.maxLevels, this.level + 1);
    this.nodes[1] = new QuadTreeNode(x, y, subWidth, subHeight, this.maxObjects, this.maxLevels, this.level + 1);
    this.nodes[2] = new QuadTreeNode(x, y + subHeight, subWidth, subHeight, this.maxObjects, this.maxLevels, this.level + 1);
    this.nodes[3] = new QuadTreeNode(x + subWidth, y + subHeight, subWidth, subHeight, this.maxObjects, this.maxLevels, this.level + 1);
  }

  // 获取对象所在的子节点
  getIndex(rect) {
    const verticalMidpoint = this.x + this.width / 2;
    const horizontalMidpoint = this.y + this.height / 2;

    const topQuadrant = rect.y < horizontalMidpoint && rect.y + rect.height < horizontalMidpoint;
    const bottomQuadrant = rect.y > horizontalMidpoint;

    let index = -1;

    if (rect.x < verticalMidpoint && rect.x + rect.width < verticalMidpoint) {
      if (topQuadrant) {
        index = 1;
      } else if (bottomQuadrant) {
        index = 2;
      }
    } else if (rect.x > verticalMidpoint) {
      if (topQuadrant) {
        index = 0;
      } else if (bottomQuadrant) {
        index = 3;
      }
    }

    return index;
  }

  // 插入对象到四叉树中
  insert(rect) {
    if (this.nodes.length) {
      const index = this.getIndex(rect);

      if (index !== -1) {
        this.nodes[index].insert(rect);
        return;
      }
    }

    this.objects.push(rect);

    if (this.objects.length > this.maxObjects && this.level < this.maxLevels) {
      if (!this.nodes.length) {
        this.split();
      }

      let i = 0;
      while (i < this.objects.length) {
        const index = this.getIndex(this.objects[i]);
        if (index !== -1) {
          this.nodes[index].insert(this.objects.splice(i, 1)[0]);
        } else {
          i++;
        }
      }
    }
  }

  // 获取所有与指定对象碰撞的对象
  retrieve(rect) {
    const index = this.getIndex(rect);
    let foundObjects = this.objects;

    if (this.nodes.length) {
      if (index !== -1) {
        foundObjects = foundObjects.concat(this.nodes[index].retrieve(rect));
      } else {
        for (let i = 0; i < this.nodes.length; i++) {
          foundObjects = foundObjects.concat(this.nodes[i].retrieve(rect));
        }
      }
    }

    return foundObjects;
  }
}

// 定义游戏场景类
class GameScene {
  constructor() {
    this.snake = null; // 贪吃蛇
    this.foods = []; // 食物
    this.quadTree = new QuadTreeNode(0, 0, 960, 640, 10, 5, 0); // 四叉树
  }

  // 初始化游戏场景
  init() {
    // 创建贪吃蛇和食物
    this.snake = new Snake();
    for (let i = 0; i < 10; i++) {
      const food = new Food();
      this.foods.push(food);
      this.quadTree.insert(food.rect);
    }
  }

  // 更新游戏场景
  update(dt) {
    // 移动贪吃蛇
    this.snake.move(dt);

    // 检测贪吃蛇与食物的碰撞
    const snakeRect = this.snake.getRect();
    const collidedFoods = this.quadTree.retrieve(snakeRect);
    for (let i = 0; i < collidedFoods.length; i++) {
      const food = collidedFoods[i];
      if (this.snake.checkCollision(food.rect)) {
        // 贪吃蛇吃到了食物
        this.snake.eat(food);
        // 从场景中移除食物
        this.foods.splice(this.foods.indexOf(food), 1);
        this.quadTree.objects.splice(this.quadTree.objects.indexOf(food.rect), 1);
        // 创建新的食物并加入场景
        const newFood = new Food();
        this.foods.push(newFood);
        this.quadTree.insert(newFood.rect);
      }
    }
  }

  // 渲染游戏场景
  render() {
    // 渲染贪吃蛇和食物
    this.snake.render();
    for (let i = 0; i < this.foods.length; i++) {
      this.foods[i].render();
    }
  }
}

// 定义食物类
class Food {
  constructor() {
    this.rect = new Rect(Math.floor(Math.random() * 960), Math.floor(Math.random() * 640), 10, 10);
  }

  render() {
    // 渲染食物
  }
}

// 定义矩形类
class Rect {
  constructor(x, y, width, height) {
    this.x = x;
    this.y = y;
    this.width = width;
    this.height = height;
  }
}

// 定义贪吃蛇类
class Snake {
  constructor() {
    this.body = [new Rect(100, 100, 10, 10), new Rect(90, 100, 10, 10), new Rect(80, 100, 10, 10)];
    this.direction = 'right';
  }

  // 移动贪吃蛇
  move(dt) {
    // 根据方向移动贪吃蛇
  }

  // 检测贪吃蛇与其他对象的碰撞
  checkCollision(rect) {
    // 检测贪吃蛇头部是否与指定矩形相交
  }

  // 贪吃蛇吃到食物
  eat(food) {
    // 在贪吃蛇尾部添加一个新的矩形
  }

  // 获取贪吃蛇的矩形
  getRect() {
    // 返回贪吃蛇头部的矩形
  }

  render() {
    // 渲染贪吃蛇
  }
}

// 创建游戏场景对象并初始化
const gameScene = new GameScene();
gameScene.init();

// 游戏循环
function gameLoop(dt) {
  // 更新游戏场景
  gameScene.update(dt);

  // 渲染游戏场景
  gameScene.render();

  // 继续下一帧循环
  requestAnimationFrame(gameLoop);
}

// 开始游戏循环
requestAnimationFrame(gameLoop);

以上代码仅为示例，实际使用时需要根据项目需求进行修改。