代码片段：(function(){ varApp,Pixr,Random,Utils,Vec,log,rnd,twopi,utl; Vec=(function(){  vardegrees2radian,radian2degrees;  classVec{   constructor(x,y){    this.x=x||0;    this.y=y||0;    if(!(thisinstanceofVec)){     newthis(x,y);    }   }