HTML+CSS+JS實作 ??貪吃蛇游戲、你能吃過我？??【原始碼送給你一起來玩-建議收藏】

var sw = 20, //一個方塊的寬度
    sh = 20, //一個方塊的高度
    tr = 30, //行數
    td = 30; //列數

var snake = null; //蛇的實體
var food = null; //食物的實體
var game = null; //游戲的實體

//方塊建構式
function square(x, y, classname) {
    // 0, 0         0, 0 
    // 20, 0        1, 0
    // 40, 0        2, 0

    this.x = x * sw;
    this.y = y * sh;
    this.class = classname;

    this.viewContent = document.createElement("div"); //方塊對應的DOM元素
    this.viewContent.className = this.class;
    this.parent = document.getElementById("snakeWrap"); //方塊的父級，并添加到頁面

}
square.prototype.create = function() { //創建方塊DOM
    this.viewContent.style.position = "absolute";
    this.viewContent.style.width = sw + "px";
    this.viewContent.style.height = sh + "px";
    this.viewContent.style.left = this.x + "px";
    this.viewContent.style.top = this.y + "px";

    this.parent.appendChild(this.viewContent);
}

square.prototype.remove = function() {
    //removeChild()  ===  從串列中洗掉一個專案
    this.parent.removeChild(this.viewContent);
}

//蛇
function Snake() {
    this.head = null; //存一個蛇頭的資訊
    this.tail = null; //存一個蛇尾的資訊
    this.pos = []; //存盤蛇身上的每一個方塊的位置

    this.directionNum = { //存盤蛇走的方向，用一個物件來表示
        left: {
            x: -1,
            y: 0,
            rotate: 180 //蛇頭在不同的方向中應該進行旋轉，要不始終是向右
        },
        right: {
            x: 1,
            y: 0,
            rotate: 0
        },
        up: {
            x: 0,
            y: -1,
            rotate: -90
        },
        down: {
            x: 0,
            y: 1,
            rotate: 90
        },
    }
}

Snake.prototype.init = function() {
    //創建蛇頭
    var snakeHead = new square(2, 0, "snakeHead");
    snakeHead.create();
    this.head = snakeHead; //存盤蛇頭資訊
    this.pos.push([2, 0]) //把蛇頭的位置存起來

    //創建蛇身體1
    var snakebody1 = new square(1, 0, "snakeBody");
    snakebody1.create();
    this.pos.push([1, 0]); //把蛇身的位置存起來

    //創建蛇身體2
    var snakebody2 = new square(0, 0, "snakeBody");
    snakebody2.create();
    this.tail = snakebody2; //把蛇尾的資訊存起來
    this.pos.push([0, 0]); //把蛇身的位置存起來

    //形成鏈表關系
    snakeHead.last = null;
    snakeHead.next = snakebody1;

    snakebody1.last = snakeHead;
    snakebody1.next = snakebody2;

    snakebody2.last = snakebody1;
    snakebody2.next = null;

    //給蛇添加一條屬性，用來表示蛇走的方向
    this.direction = this.directionNum.right; //默認讓蛇往右走
}

//這個方法用來獲取蛇頭的下一個位置對應的元素，要根據素材做不同的事情
Snake.prototype.getNextPos = function() {
    var nextPos = [ //蛇頭要走的下一個點的坐標
        this.head.x / sw + this.direction.x,
        this.head.y / sh + this.direction.y
    ]

    //下個點是自己，代表撞到了自己，游戲結束
    var selfCollied = false;
    this.pos.forEach(function(value) {
        if (value[0] == nextPos[0] && value[1] == nextPos[1]) {
            //如果陣列中的兩個陣列都相等，就說明下一個點在蛇身上里面能找到，代表撿到自己了
            selfCollied = true;
        }
    })
    if (selfCollied) {
        console.log("撞到自己了！");
        this.strategies.die.call(this);
        return;
    }

    //下個點是圍墻，游戲結束
    if (nextPos[0] < 0 || nextPos[1] < 0 || nextPos[0] > td - 1 || nextPos[1] > tr - 1) {
        console.log("撞墻了！");
        this.strategies.die.call(this);
        return;
    }

    //下個點是食物，吃
    if (food && food.pos[0] == nextPos[0] && food.pos[1] == nextPos[1]) {
        //如果這個條件成立說明現在蛇頭要走的的下一個點是食物的那個點
        console.log("撞到食物了！ ");
        this.strategies.eat.call(this);
        return;
    }

    //下個點什么都不是，走
    this.strategies.move.call(this);
}

//處理碰撞后要做的事
Snake.prototype.strategies = {
    move: function(format) { //這個引數用于決定要不要洗掉最后一個方塊（蛇尾），當傳了這個引數后就表示要做的事情是吃
        //創建新身體（在舊蛇頭的位置）
        var newBody = new square(this.head.x / sw, this.head.y / sh, "snakeBody");
        //更新鏈表的關系
        newBody.next = this.head.next;
        newBody.next.last = newBody;
        newBody.last = null;

        this.head.remove(); //把舊蛇頭原來的位置洗掉
        newBody.create();

        //創建一個新蛇頭（蛇頭下一個要走到的點nexpos）
        var newHead = new square(this.head.x / sw + this.direction.x, this.head.y / sh + this.direction.y, "snakeHead");
        //更新鏈表的關系
        newHead.next = newBody;
        newHead.last = null;
        newBody.last = newHead;
        newHead.viewContent.style.transform = "rotate(" + this.direction.rotate + "deg)"
        newHead.create();

        //蛇身上的每一個方塊的坐標也要更新
        this.pos.splice(0, 0, [this.head.x / sw + this.direction.x, this.head.y / sh + this.direction.y, ]);
        this.head = newHead; //還要把this.head的資訊更新一下

        if (!format) { //如果format的值為lafse，表示需要洗掉（除了吃之外的操作）
            this.tail.remove();
            this.tail = this.tail.last;

            this.pos.pop();
        }
    },
    eat: function() {
        this.strategies.move.call(this, true);
        createFood();
        game.score++;
    },
    die: function() {
        game.over();
    }
}

snake = new Snake();

//創建食物
function createFood() {
    //食物小方塊的隨機坐標
    var x = null;
    var y = null;

    var include = true; //回圈跳出的條件，true表示食物的坐標在蛇身上（需要繼續回圈），false表示食物的坐標不在蛇身上（不回圈了）
    while (include) {
        x = Math.round(Math.random() * (td - 1));
        y = Math.round(Math.random() * (tr - 1));

        snake.pos.forEach(function(value) {
            if (x != value[0] && y != value[1]) {
                //這個條件成立說明現在隨機出來的這個坐標，在蛇身上并沒有找到，
                include = false;
            }
        })
    }
    //生成食物
    food = new square(x, y, "food");
    food.pos = [x, y]; //存盤一下食物生成的坐標，用于跟蛇頭要走的下一個點做對比

    var foodDom = document.querySelector('.food');
    if (foodDom) {
        foodDom.style.left = x * sw + "px";
        foodDom.style.top = y * sh + "px";
    } else {
        food.create();
    }
}



//創建游戲邏輯
function Game() {
    this.timer = null;
    this.score = 0;
}

Game.prototype.init = function() {
    snake.init();
    // snake.getNextPos();
    createFood();

    document.onkeydown = function(ev) {
        if (ev.which == 37 && snake.direction != snake.directionNum.right) { //用戶按下左鍵的時候，這條蛇不能是正下往右走
            snake.direction = snake.directionNum.left;
        } else if (ev.which == 38 && snake.direction != snake.directionNum.down) {
            snake.direction = snake.directionNum.up;
        } else if (ev.which == 39 && snake.direction != snake.directionNum.left) {
            snake.direction = snake.directionNum.right;
        } else if (ev.which == 40 && snake.direction != snake.directionNum.up) {
            snake.direction = snake.directionNum.down;
        }
    }

    this.start();
}
Game.prototype.start = function() { //開始游戲
    this.timer = setInterval(function() {
        snake.getNextPos();
    }, 200);
}

Game.prototype.pause = function() {
    clearInterval(this.timer);
}

Game.prototype.over = function() {
    clearInterval(this.timer);
    alert("你的得分為：" + game.score);

    //游戲回到最初的狀態
    var snakewrap = document.getElementById("snakeWrap");
    snakewrap.innerHTML = "";

    snake = new Snake();
    game = new Game();

    var startBtnWrap = document.querySelector(".startBtn");
    startBtnWrap.style.display = "block";
}

//開啟游戲
game = new Game();
var startBtn = document.querySelector(".startBtn button");
startBtn.onclick = function() {
    startBtn.parentNode.style.display = "none";
    game.init();
}

//暫停
var snakewrap = document.getElementById("snakeWrap");
var pauseBtn = document.querySelector(".pauseBtn");
snakewrap.onclick = function() {
    game.pause();

    pauseBtn.style.display = "block";
}

pauseBtn.onclick = function() {
    game.start();
    pauseBtn.style.display = "none";
}

.content {
    width: 640px;
    height: 640px;
    margin: 50px auto 0px auto;
    position: relative;
}

.btn {
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    background-color: rgba(0, 0, 0, 0.3);
    z-index: 2;
}

.btn button {
    background: none;
    border: none;
    background-size: 100% 100%;
    cursor: pointer;
    outline: none;
    position: absolute;
    left: 50%;
    top: 50%;
}

.startBtn button {
    width: 200px;
    height: 80px;
    background-image: url(../images/startGame.png);
    margin-left: -100px;
    margin-top: -40px;
}

.pauseBtn {
    display: none;
}

.pauseBtn button {
    width: 70px;
    height: 70px;
    background-image: url(../images/start.png);
    margin-left: -35px;
    margin-top: -35px;
}

/*snakeWrap*/

#snakeWrap {
    width: 600px;
    height: 600px;
    background-color: #225675;
    border: 20px solid #7dd9ff;
    position: relative;
}

/* #snakeWrap div {
    width: 20px;
    height: 20px;
} */

.snakeHead {
    background-image: url(../images/snake.png);
    background-size: cover;
}

.snakeBody {
    background-color: #9ddbb1;
    border-radius: 50%;
}

.food {
    background-image: url(../images/food.png);
    background-size: cover;
}