[ActionScript 3.0] AS3.0 对象在一定范围随机显示不重叠

import flash.geom.Rectangle;
import flash.display.MovieClip;
import flash.display.Sprite;

var arr:Array = [];
var dis:Number = 20;//间距
var len:int=15;//对象数量
var bound:Rectangle = new Rectangle(0,0,1000,800);//显示范围
for(var i:int = 0;i<len;i++){
var obj:Sprite = new Sprite();
obj.graphics.beginFill(0xcccccc);
obj.graphics.drawRect(0,0,120,100);
obj.graphics.endFill();
obj.name = "obj_"+i;
arr.push(obj);
this.addChild(obj);
}
reset();
function reset():void{
for(var j:int = 0;j<len;j++){
setPosition(this.getChildByName("obj_"+j) as Sprite);
//test(this.getChildByName("obj_"+j) as Sprite);
}
}
function setPosition(obj:Sprite):void
{
obj.x = Math.random()*(bound.width-obj.width)+bound.x;
obj.y = Math.random()*(bound.height-obj.height)+bound.y;
for(var i:int = 0;i<arr.length;i++){
if(obj != arr[i]){
//不重叠，没有间距
/*if(obj.hitTestObject(arr[i])){
setPosition(obj);
return;
}*/
//不重叠，并有一定间距dis，间距为0效果同上
if(Math.abs(obj.x-arr[i].x)<obj.width+dis&&Math.abs(obj.y-arr[i].y)<obj.height+dis){
setPosition(obj);
return;
}
}
}
}
//检测是否重合
function test(obj:Sprite):void
{
for(var i:int = 0;i<len;i++){
if(obj != arr[i]){
if(obj.hitTestObject(arr[i])){
trace(obj.name,arr[i].name);
}
}
}
}