FLASH AS3 画扇形函数

/*
*Create by Geordi 14th Feb 2008
*function DrawSector is drawing a sector in the flash by actionscript 3 
*/
import flash.display.MovieClip;
import flash.display.Sprite;
var stag:Sprite=new Sprite();
addChild(stag);
var moviec:MovieClip=new MovieClip;
stag.addChild(moviec);
var S_angle:int=60;
/* S_angle is expressed as a number between 0 and 360 degrees. it will draw a 60 
* degree sector in this example, but you could change it to what ever you want
*/
DrawSector(moviec,200,200,100,S_angle,270,0xffcc00);
function DrawSector(mc:MovieClip,x:Number=200,y:Number=200,r:Number=100,
angle:Number=27,startFrom:Number=270,color:Number=0xff0000):void
/*
* mc the movieclip: the container of the sector.
* x,y the center position of the sector
* r the radius of the sector
* angle the angle of the sector
* startFrom the start degree counting point : 270 top, 180 left, 0 right, 90 bottom ,
* it is counting from top in this example. 
* color the fil lin color of the sector
*/
{

/* start to fill the sector with the variable "color" if you want a sector without filling color ,
* please remove next line below.
*/
mc.graphics.beginFill(color,50); //remove this line to unfill the sector
/* the border of the secetor with color 0xff0000 (red) , you could replace it with any color
* you want like 0x00ff00(green) or 0x0000ff (blue).
*/
mc.graphics.lineStyle(0,0xff0000);
mc.graphics.moveTo(x,y);
angle=(Math.abs(angle)>360)?360:angle;
var n:Number=Math.ceil(Math.abs(angle)/45);
var angleA:Number=angle/n;
angleA=angleA*Math.PI/180;
startFrom=startFrom*Math.PI/180;
mc.graphics.lineTo(x+r*Math.cos(startFrom),y+r*Math.sin(startFrom));
for(var i=1;i<=n;i++)
{
startFrom+=angleA;
var angleMid=startFrom-angleA/2;
var bx=x+r/Math.cos(angleA/2)*Math.cos(angleMid);
var by=y+r/Math.cos(angleA/2)*Math.sin(angleMid);
var cx=x+r*Math.cos(startFrom);
var cy=y+r*Math.sin(startFrom);
mc.graphics.curveTo(bx,by,cx,cy);
}
if(angle!=360)
mc.graphics.lineTo(x,y);

mc.graphics.endFill(); // if you want a sector without filling color , please remove this line.
}
////////////////////////////////////////runing result////////////////////////////////////////////////////////

  sector with fill in color: sector without fill in color: