javascript 实现双指放大缩小旋转图片详解编程语言

private getTouchDistance():number 
{ 
var _distance:number = 0; 
var names = this.touchPoints["names"]; 
_distance = egret.Point.distance( this.touchPoints[names[names.length-1]], 
this.touchPoints[names[names.length-2]]); 
return _distance; 
}

  private getTouchAngle():number 
    { 
        var ang:number = 0; 
        var names = this.touchPoints["names"]; 
        var p1:egret.Point = this.touchPoints[names[names.length-1]]; 
        var p2:egret.Point = this.touchPoints[names[names.length-2]]; 
 
        ang = Math.atan2((p1.y-p2.y),(p1.x-p2.x)) / this.c; 
        return ang; 
    }