# Yahoo! UI Library

### animation

Yahoo! UI Library > animation > Bezier.js (source view)

    /**
     * Used to calculate Bezier splines for any number of control points.
     * @class Bezier
     * @namespace YAHOO.util
     *
     */
    YAHOO.util.Bezier = new function()
    {
       /**
        * Get the current position of the animated element based on t.
        * Each point is an array of "x" and "y" values (0 = x, 1 = y)
        * At least 2 points are required (start and end).
        * First point is start. Last point is end.
        * Additional control points are optional.
        * @method getPosition
        * @param {Array} points An array containing Bezier points
        * @param {Number} t A number between 0 and 1 which is the basis for determining current position
        * @return {Array} An array containing int x and y member data
        */
       this.getPosition = function(points, t)
       {
          var n = points.length;
          var tmp = [];

          for (var i = 0; i < n; ++i){
             tmp[i] = [points[i][0], points[i][1]]; // save input
          }

          for (var j = 1; j < n; ++j) {
             for (i = 0; i < n - j; ++i) {
                tmp[i][0] = (1 - t) * tmp[i][0] + t * tmp[parseInt(i + 1, 10)][0];
                tmp[i][1] = (1 - t) * tmp[i][1] + t * tmp[parseInt(i + 1, 10)][1];
             }
          }

          return [ tmp[0][0], tmp[0][1] ];

       };
    };

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