# Yahoo! UI Library

### anim 3.0.0b1

Yahoo! UI Library > anim > anim-curve.js (source view)
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    /**
     * Adds support for the <code>curve</code> property for the <code>to</code>
     * attribute.  A curve is zero or more control points and an end point.
     * @module anim
     * @submodule anim-curve
     */

    Y.Anim.behaviors.curve = {
        set: function(anim, att, from, to, elapsed, duration, fn) {
            from = from.slice.call(from);
            to = to.slice.call(to);
            var t = fn(elapsed, 0, 100, duration) / 100;
            to.unshift(from);
            anim._node.setXY(Y.Anim.getBezier(to, t));
        },

        get: function(anim, att) {
            return anim._node.getXY();
        }
    };

    /**
     * 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.
     * @for Anim
     * @method getBezier
     * @static
     * @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
     */
    Y.Anim.getBezier = 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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