问在鼠标滚轮上快速平滑滚动

EN

jQuery.extend(jQuery.easing, {
  easeOutQuint: function(x, t, b, c, d) {
    return c * ((t = t / d - 1) * t * t * t * t + 1) + b;
  }
});

var wheel = false,
  $docH = $(document).height() - $(window).height(),
  $scrollTop = $(window).scrollTop();

$(window).bind('scroll', function() {
  if (wheel === false) {
    $scrollTop = $(this).scrollTop();
  }
});
$(document).bind('DOMMouseScroll mousewheel', function(e, delta) {
  delta = delta || -e.originalEvent.detail / 3 || 
  e.originalEvent.wheelDelta / 5; //edit this to your needs - the higher the slower
  wheel = true;

  $scrollTop = Math.min($docH, Math.max(0, parseInt($scrollTop - delta * 30)));
  $($.browser.webkit ? 'body' : 'html').stop().animate({
    scrollTop: $scrollTop + 'px'
  }, 2000, 'easeOutQuint', function() {
    wheel = false;
  });
  return false;
});