Bezier2.js

var Bezier2 = (function(){
    /**
     * class Point
     * @param {number} x
     * @param {number} y
     */
    var Point = (function(){
      function Point(x, y){
        this.x = x || 0;
        this.y = y || 0;
      }
      return Point
    })();

    /**
     * class Bezier2 2次ベジェ
     * @param targetElm
     * @param {number} x1
     * @param {number} y1
     * @param {number} x2
     * @param {number} y2
     * @param {number} x3
     * @param {number} y3
     * @constructor
     */
    function Bezier2(targetElm, x1, y1, x2, y2, x3, y3){
      this.target = targetElm;
      this.p1 = new Point(x1 || 0, y1 || 0);
      this.p2 = new Point(x2 || 0, y2 || 0);
      this.p3 = new Point(x3 || 0, y3 || 0);
    }

    /**
     * __X__ 2次ベジェ X座標算出
     * @param {number} t
     * @return {number}
     */
    Bezier2.prototype.__X__ = function(t){
      var _x1 = (1 - t) * (1 - t) * this.p1.x;
      var _x2 = 2 * (1 - t) * t * this.p2.x;
      var _x3 = t * t * this.p3.x;
      return _x1 + _x2 + _x3;
    };
    /**
     * __Y__ 2次ベジェ Y座標算出
     * @param {number} t
     * @return {number}
     */
    Bezier2.prototype.__Y__ = function(t){
      var _y1 = (1 - t) * (1 - t) * this.p1.y;
      var _y2 = 2 * (1 - t) * t * this.p2.y;
      var _y3 = t * t * this.p3.y;
      return _y1 + _y2 + _y3;
    };
    /**
     * putCoor 座標を取得する
     * @param {Number} t  0 <= t <= 1
     * @return {Point}
     */
    Bezier2.prototype.putCoor = function(t){
      return new Point(this.__X__(t), this.__Y__(t));
    };
    /**
     * pos ターゲット要素のposition値を設定
     * @param {Number} t  0 <= t <= 1
     */
    Bezier2.prototype.pos = function(t){
      this.target.css({top :this.__Y__(t), left :this.__X__(t)});
    };
    /**
     * animateBizier
     * @param {Number} msec
     * @param {Number} fps
     */
    Bezier2.prototype.animateBizier = function(msec, fps){
      fps = 1000 / fps || 1000 / 60;
      var _self = this;
      var _count = 0;
      var _frame = 0;
      var _end = (msec / fps) | 0;
      var timer = setInterval(function(){
        _frame = fps / msec * _count;
        _self.pos(_frame);
        if(_end === _count){
          clearInterval(timer);
          _self.pos(1);
        }
        _count++;
      }, fps);
    };
    return Bezier2;
  }());