定义 游戏引擎 对象

···var gGameBox = {
rows: 20, 行数
cols: 20, /列数
allTds: [], 存储所有的td元素对象
food: null, 食物对象
snake: null, 蛇对象
timer: null, 定时器···

方法： 清空环境

··· clear: function() {
for (var i = 0; i < gGameBox.allTds.length; i++) {
for (var j = 0; j < gGameBox.allTds[i].length; j++) {
gGameBox.allTds[i][j].className = "";
}
}
},
···

方法：支持键盘控制

··· keyControl: function() {
// onkeydown
window.onkeydown = function(e) {

        var c = e.keyCode;
        if (c == 37)
        {

            if (gGameBox.snake.direct == "right")
            {
                return ;
            }
            gGameBox.snake.direct = "left";
        }
        else if (c == 38)
        {
            if (gGameBox.snake.direct == "down")
            {
                return ;
            }
            gGameBox.snake.direct = "up";
        }
        else if (c == 39)
        {
            if (gGameBox.snake.direct == "left")
            {
                return ;
            }
            gGameBox.snake.direct = "right";
        }
        else if (c == 40)
        {
            if (gGameBox.snake.direct == "up")
            {
                return ;
            }
            gGameBox.snake.direct = "down";
        }
    }
},

start: function() {

    gGameBox.init(); // 游戏初始化
    
    gGameBox.food = new Food(); // 创建食物
    gGameBox.snake = new Snake(); // 创建蛇
    gGameBox.keyControl();
    gGameBox.timer = setInterval(function() {
        gGameBox.clear();
        gGameBox.snake.move();
        gGameBox.food.show();
    }, 500);

    //gGameBox.snake.fresh();
},

···
## 初始化
···init: function() {
var oTable = document.createElement("table");
for (var i = 0; i < gGameBox.rows; i++)
{
r oTr = document.createElement("tr");
var arr = [];
for (var j = 0; j < gGameBox.cols; j++) {
var oTd = document.createElement("td");
arr.push(oTd);
}
gGameBox.allTds.push(arr);

        oTable.appendChild(oTr);
    }
    document.body.appendChild(oTable);
}

};···