参照百度的贪吃蛇教程,制作一个贪吃蛇小游戏

从零开始太难下手,于是参考百度的教程制作了一个贪吃蛇小游戏,

目前只实现了贪吃蛇最基本的功能,积分面板与暂停开始功能都没有做,其余的bug以后也慢慢完善

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script>
        function Map() {
            //定义地图的属性
            this.width = 800;
            this.height = 400;
            this.color = '#ddd';
            this.position = 'relative';

            this.mapShow = function() {
                //生成地图
                var box = document.createElement('div');
                box.style.width = this.width + 'px';
                box.style.height = this.height + 'px';
                box.style.backgroundColor = this.color;
                box.style.position = this.position;
                document.getElementsByTagName('body')[0].appendChild(box);
            }
        };

        function Food() {
            //定义食物的属性
            this.width = 20;
            this.height = 20;
            this.color = 'green';
            this.position = 'absolute';
            
            this.randomShow = function() {
                this.disX = Math.floor(Math.random()*40);
                this.disY = Math.floor(Math.random()*20);//生成随机的食物
                var food = document.createElement('span');
                food.style.width = this.width + 'px';
                food.style.height = this.height + 'px';
                food.style.backgroundColor = this.color;
                food.style.position = this.position;
                food.style.left = this.disX * 20 + 'px';
                food.style.top = this.disY * 20 + 'px';
                document.getElementsByTagName('div')[0].appendChild(food);//将食物放入地图
            }
        };

        function Snake() {
            this.width = 20;
            this.height = 20;
            this.position = 'absolute';
            this.body = [[3,2,'red'],[2,2,'blue'],[1,2,'blue']];//蛇的每一隔用数组保存,第一格与横坐标有关,第二个与纵坐标有关
            this.direct = 'right';

            this.showSnake = function() {//生成蛇
                for(var i = 0;i < this.body.length;i++){
                    var snake = document.createElement('div');
                    snake.style.width = this.width + 'px';
                    snake.style.height = this.height + 'px';
                    snake.style.position = this.position;
                    snake.style.left = this.body[i][0]*20 + 'px';
                    snake.style.top = this.body[i][1]*20 + 'px';
                    snake.style.backgroundColor = this.body[i][2];
                    document.getElementsByTagName('div')[0].appendChild(snake);
                } 
            };

            this.move = function(food,timer) {
                var container = document.getElementsByTagName("div")[0];
                var snakeBody = container.getElementsByTagName("div");
                var foodBody = container.getElementsByTagName("span")[0];
                var length = snakeBody.length;

                for(var i=0;i<length;i++){
                    container.removeChild(snakeBody[0]);
                }

                for(var i=this.body.length-1;i>0;i--){
                    this.body[i][0] = this.body[i-1][0];
                    this.body[i][1] = this.body[i-1][1];
                }
                if(this.direct == 'right') {
                    this.body[0][0]++;
                }else if(this.direct == 'left') {
                    this.body[0][0]--;
                }else if(this.direct == 'up') {
                    this.body[0][1]--;
                }else{
                    this.body[0][1]++;
                }

                //贪吃蛇吃食物
                if(this.body[0][0] == food.disX && this.body[0][1] == food.disY){
                    container.removeChild(foodBody);//吃掉的食物消失
                    this.body.push([-3,-3,'blue']);
                    food.randomShow();//生成新的食物
                }

                this.showSnake();
                //判断是否撞墙
                if(snakeBody[0].offsetLeft<(container.offsetLeft-40) || snakeBody[0].offsetLeft>=container.offsetWidth || snakeBody[0].offsetTop<(container.offsetTop-40) || snakeBody[0].offsetTop>container.offsetHeight){
                    alert("游戏结束");
                    clearInterval(timer);
                }
                //判断是否撞到自己
                for(var i=1;i<this.body.length;i++){
                    if(this.body[0][0] == this.body[i][0] && this.body[0][1] == this.body[i][1]){
                        alert("游戏结束");
                        clearInterval(timer);
                    }
                }

            };

            //定义方向
            this.setDirect = function(code) {
                switch(code) {
                    case 37:
                        if(this.direct != 'right'){//防止蛇掉头
                            this.direct = 'left';
                        }
                        break;
                    case 38:
                        if(this.direct != 'down'){
                            this.direct = 'up';
                        }
                        break;
                    case 39:
                        if(this.direct != 'left'){
                            this.direct = 'right';
                        }
                        break;
                    case 40:
                        if(this.direct != 'up'){
                            this.direct = 'down';
                        }
                        break;
                }
            }
        };

        window.onload = function() {
            var obj = new Map();
            obj.mapShow();
            var food = new Food();
            food.randomShow();
            var snake = new Snake();
            snake.showSnake();
            
            var timer = setInterval(function(){snake.move(food,timer)},200);

            document.onkeydown = function(ev) {
                var oEvent = ev || event;
                code = oEvent.keyCode;
                snake.setDirect(code);
            }
        }
    </script>
</head>
<body>
    
</body>
</html>
原文地址:https://www.cnblogs.com/momomiji/p/8559875.html