let funcCurve = {
      easeInQuad: function(pos){
          return Math.pow(pos, 2);
      },
      easeOutQuad: function(pos){
          return -(Math.pow((pos-1), 2) -1);
      },
      easeInOutQuad: function(pos){
          if ((pos/=0.5) < 1) return 0.5*Math.pow(pos,2);
          return -0.5 * ((pos-=2)*pos - 2);
      },
      easeInCubic: function(pos){
          return Math.pow(pos, 3);
      },
      easeOutCubic: function(pos){
          return (Math.pow((pos-1), 3) +1);
      },
      easeInOutCubic: function(pos){
          if ((pos/=0.5) < 1) return 0.5*Math.pow(pos,3);
          return 0.5 * (Math.pow((pos-2),3) + 2);
      },
      easeInQuart: function(pos){
          return Math.pow(pos, 4);
      },
      easeOutQuart: function(pos){
          return -(Math.pow((pos-1), 4) -1)
      },
      easeInOutQuart: function(pos){
          if ((pos/=0.5) < 1) return 0.5*Math.pow(pos,4);
          return -0.5 * ((pos-=2)*Math.pow(pos,3) - 2);
      },
      easeInQuint: function(pos){
          return Math.pow(pos, 5);
      },
      easeOutQuint: function(pos){
          return (Math.pow((pos-1), 5) +1);
      },
      easeInOutQuint: function(pos){
          if ((pos/=0.5) < 1) return 0.5*Math.pow(pos,5);
          return 0.5 * (Math.pow((pos-2),5) + 2);
      }
}