把圆形切成等分的算法

比如我要把圆形切成30等分，代码如下：

import flash.display.Shape;
var k:int =30;//切成30等分

var cx:Number = 375/2;
var cy:Number = 667/2;
var cr:Number =cx-10;
var line:Shape = new Shape();
line.graphics.lineStyle(1,RandRGB());
function draw1(x1:Number,y1:Number):void{
line.graphics.moveTo(cx,cy);

line.graphics.lineTo(x1,y1);
}


var okx:Number;
var oky:Number;
var d:Number;
for(var i:int=0;i<k;i++){
    var dd:int = 360/k;
    var d2:Number = i*dd;

        if(d2==0){
            okx = cx;
            oky = cy-cr;
        }else if(d2==180){
            okx = cx;
            oky = cy+cr;
        }else if(d2==270){
            okx = cx-cr;
            oky = cy;
        }else if(d2==90){
            okx = cx+cr;
            oky = cy;
        }else{

            if(d2<90){
                d = d2*Math.PI/180;
                okx = cx+cr*Math.sin(d);
                oky = cy-cr*Math.cos(d);
            }
            else if(d2>90&&d2<180)
            {
                d= (d2-90)*Math.PI/180;
                okx = cx+cr*Math.cos(d);
                oky = cy+cr*Math.sin(d);
            }else if(d2>180&&d2<270)
            {
                d = (360-90-d2)*Math.PI/180;
                okx = cx-cr*Math.cos(d);
                oky = cy+cr*Math.sin(d);        
            }else if(d2>270){
                d = (360-d2)*Math.PI/180;
                okx = cx-cr*Math.sin(d);
                oky = cy-cr*Math.cos(d);
            }

        }

        draw1(okx,oky);
        //trace(cx,cy,cr,okx,oky,d2,d);
}

var c:Shape = new Shape(); 

c.graphics.lineStyle(2,0);
c.graphics.drawCircle(cx,cy,cr);

c.graphics.drawCircle(cx,cy,cr*0.8);
c.graphics.drawCircle(cx,cy,cr*0.64);

addChild(line);
addChild(c);

function RandRGB():uint {
  return (Math.random() * 0xffffff + 0x000000);
}