Untitled

How to make animation easing (ease-in and ease-out) duration-independent?
Short animation (X milliseconds)
|<<<<|-------------------|>>>>|
 10ms                     10ms

Long animation (2X milliseconds)
|<<<<|-----------------------------------------|>>>>|
 10ms                                           10ms

var $obj     = $('#some-id'),
    ani_dist = 500;

//animate first easing
$obj.stop().animate({ left : 100 }, 500, 'easeOutCirc', function () {

    //animate main body of the animation
    $obj.animate({ left : (ani_dist - 100) }, 1000, 'linear', function () {

        //animate the last easing
        $obj.animate({ left : ani_dist }, 500, 'easeInCirc');
    });
});