努力在p5 js中创建一条移动顺畅的蛇-尾巴迎头赶上

let snake = [];
let snakeSize = 20;
let food = {};

function setup() {
  createCanvas(400, 400);
  frameRate(10); // 控制蛇的移动速度

  // 初始化蛇的位置
  let x = width / 2;
  let y = height / 2;
  for (let i = 0; i < 4; i++) {
    snake.push(createVector(x, y));
    x -= snakeSize;
  }

  // 生成食物的位置
  generateFood();
}

function draw() {
  background(220);

  // 获取用户的输入来改变蛇的移动方向
  if (keyIsDown(UP_ARROW) && snake[0].y !== snake[1].y) {
    snake[0].y -= snakeSize;
  } else if (keyIsDown(DOWN_ARROW) && snake[0].y !== snake[1].y) {
    snake[0].y += snakeSize;
  } else if (keyIsDown(LEFT_ARROW) && snake[0].x !== snake[1].x) {
    snake[0].x -= snakeSize;
  } else if (keyIsDown(RIGHT_ARROW) && snake[0].x !== snake[1].x) {
    snake[0].x += snakeSize;
  }

  // 更新蛇的位置
  for (let i = snake.length - 1; i > 0; i--) {
    snake[i].x = snake[i - 1].x;
    snake[i].y = snake[i - 1].y;
  }

  // 判断蛇是否碰到边界或自身
  if (snake[0].x < 0 || snake[0].x >= width || snake[0].y < 0 || snake[0].y >= height) {
    gameOver();
  }
  for (let i = 1; i < snake.length; i++) {
    if (snake[0].x === snake[i].x && snake[0].y === snake[i].y) {
      gameOver();
    }
  }

  // 判断蛇头是否碰到食物
  if (snake[0].x === food.x && snake[0].y === food.y) {
    snake.push(createVector(food.x, food.y));
    generateFood();
  }

  // 在画布上绘制蛇和食物
  drawSnake();
  drawFood();
}

function keyPressed() {
  // 根据用户的按键来改变蛇的移动方向
  if (keyCode === UP_ARROW && snake[0].y !== snake[1].y) {
    snake[0].y -= snakeSize;
  } else if (keyCode === DOWN_ARROW && snake[0].y !== snake[1].y) {
    snake[0].y += snakeSize;
  } else if (keyCode === LEFT_ARROW && snake[0].x !== snake[1].x) {
    snake[0].x -= snakeSize;
  } else if (keyCode === RIGHT_ARROW && snake[0].x !== snake[1].x) {
    snake[0].x += snakeSize;
  }
}

function drawSnake() {
  fill(0);
  for (let i = 0; i < snake.length; i++) {
    rect(snake[i].x, snake[i].y, snakeSize, snakeSize);
  }
}

function drawFood() {
  fill(255, 0, 0);
  rect(food.x, food.y, snakeSize, snakeSize);
}

function generateFood() {
  // 随机生成食物的位置
  let cols = width / snakeSize;
  let rows = height / snakeSize;
  let x = floor(random(cols)) * snakeSize;
  let y = floor(random(rows)) * snakeSize;

  // 检查生成的食物是否和蛇重叠
  for (let i = 0; i < snake.length; i++) {
    if (x === snake[i].x && y === snake[i].y) {
      return generateFood();
    }
  }

  food = createVector(x, y);
}

function gameOver() {
  noLoop(); // 停止游戏循环
  alert("Game Over");
}