javascript实现螺旋数组

javascript版本，可直接粘贴到chrome控制台下运行，
二维数组方式实现最后是一行一行打印的；
支持顺时针和逆时针旋转；
不大喜欢递归，时间空间开销都大，而且还不易修改，算位置的话就纯数学了，我的数学不大好

(function(){
    var RIGHT = 0, DOWN = 1, LEFT = 2, UP = 3;//闭包常量
    //初始化参数
    positonManager = function(length,clockwise){
        this.length = length;
		this.clockwise=clockwise;
        this.cx = 0;//当前x坐标
        this.cy = 0;//当前y坐标
        this.cn = 1;//当前数值
        this.cm = clockwise?RIGHT:DOWN;//当前移动方向
        this.positions = new Array(length);//空的二维数组
        for (var i = 0; i < length; i++) {
            this.positions[i] = new Array(length);
        }
        this.positions[0][0] = ' 1';
    }
    
    positonManager.prototype = {
        moveNext: function(){
            if (this.addNewNum(this.cm)) {//继续上次方向
                return true;
            }
            else 
                if (this.addNewNum((this.cm  + (this.clockwise?1:3))%4)) {//因为是个螺旋，转向只能按照固定次序进行循环！
                    return true;
                }
            return false;//无路可走了！
        },
        //根据方向获取下一地点后判断是否已占位，未占位则赋值，已占位返回false
        addNewNum: function(m){
            var xy = this.getNewPosition(m);
            if (xy !== false && this.positions[xy[1]][xy[0]] == undefined) {
                this.cn++;
                this.positions[xy[1]][xy[0]] = this.cn < 10 ? ' ' + this.cn : '' + this.cn;
                this.cx = xy[0];
                this.cy = xy[1];
                this.cm = m;
                return true;
            }
            return false;
        },
        //根据方向获取下一地点，越界返回false
        getNewPosition: function(dir){
            switch (dir) {
                case RIGHT:
                    return (this.cx + 1 == this.length ? false : [this.cx + 1, this.cy]);
                case DOWN:
                    return (this.cy + 1 == this.length ? false : [this.cx, this.cy + 1]);
                case LEFT:
                    return (this.cx == 0 ? false : [this.cx - 1, this.cy]);
                case UP:
                    return (this.cy == 0 ? false : [this.cx, this.cy - 1]);
            }
        },
        printAll: function(){
            var i, j,line;
            while (this.moveNext()){}
            for (i=0; i < this.length; i++) {
				line='';
                for (j=0; j < this.length; j++) {
                	line+=this.positions[i][j]+' ';
                }
				console.log(line);
            }
        }
    }
})()

console.log('int i=5;');
var thread1 = new positonManager(5,false);
thread1.printAll();
console.log('int i=6;');
var thread = new positonManager(6,true);
thread.printAll();