/*
Plugin: jQuery Parallax
Version 1.1.3
Author: Ian Lunn
Twitter: @IanLunn
Author URL: http://www.ianlunn.co.uk/
Plugin URL: http://www.ianlunn.co.uk/plugins/jquery-parallax/

Dual licensed under the MIT and GPL licenses:
http://www.opensource.org/licenses/mit-license.php
http://www.gnu.org/licenses/gpl.html
*/

(function ($) {
    var $window = $(window);
    var windowHeight = $window.height();

    $window.resize(function () {
        windowHeight = $window.height();
    });

    $.fn.parallax = function (xpos, speedFactor, outerHeight, domparallax) {
        var $this = $(this);
        var getHeight;
        var firstTop;
        var paddingTop = 0;

        //get the starting position of each element to have parallax applied to it		
        $this.each(function () {
            firstTop = $this.offset().top;
        });

        if (outerHeight) {
            getHeight = function (jqo) {
                return jqo.outerHeight(true);
            };
        } else {
            getHeight = function (jqo) {
                return jqo.height();
            };
        }

        // setup defaults if arguments aren't specified
        if (arguments.length < 1 || xpos === null) xpos = "50%";
        if (arguments.length < 2 || speedFactor === null) speedFactor = 0.1;
        if (arguments.length < 3 || outerHeight === null) outerHeight = true;
        if (arguments.length < 4 || domparallax === null) domparallax = false;

        // function to be called whenever the window is scrolled or resized
        function update() {
            var pos = $window.scrollTop();
            firstTop = $this.offset().top;
            //windowHeight = $window.height();
            $this.each(function () {
                var $element = $(this);
                var top = $element.offset().top;
                var height = getHeight($element);

                // Check if totally above or totally below viewport

                if (domparallax == false) {
                    if (top + height < pos || top > pos + $window.height()) {
                        return;
                    }
                    $this.css('backgroundPosition', xpos + " " + Math.round((firstTop - pos) * speedFactor) + "px");
                } else {
                    //$(".sbsb").html("" + pos);

                    $this.css('top', parseInt(($window.height() - 180) * speedFactor + Math.round((180 - pos) * speedFactor)) + 'px');
                }
            });
        }

        $window.bind('scroll', update).resize(update);
        update();
    };
})(jQuery);
