我有三个部分home_bg，barman，galeria。我想，滚动到感觉$（window）.scrollTop（）的部分之后添加类。当此滚动<= 0.5 *高度感觉部分时，自动滚动到顶部感觉部分。
<script>
jQuery(document).ready(function ($) {
$(window).scroll(function () {
scroll = $(window).scrollTop();
/* scrollAnch = $("section.nomargin");*/
var height_check = jQuery(window).height() ;
$(document).mousewheel(function (event) {
if (event.deltaY) {
$(window).scroll(function () {
if(scroll >= $("section#home_bg").offset().top)
{
$('section#barman').removeClass('snaps-active');
$('section#galeria').removeClass('snaps-active');
$('section#home_bg').addClass('snaps-active');
if(scroll >= ($("section#home_bg").offset().top + (0.5*height_check)))
{
$('section#home_bg').removeClass('snaps-active');
}
}
if (scroll >= $("section#barman").offset().top) {
$('section#barman').addClass('snaps-active');
$('section#galeria').removeClass('snaps-active');
$('section#home_bg').removeClass('snaps-active');
if(scroll >= ($("section#barman").offset().top + (0.5*height_check)))
{
$('section#barman').removeClass('snaps-active');
}
}
if(scroll >= ($("section#galeria").offset().top)) {
$('section#home_bg').removeClass('snaps-active');
$('section#barman').removeClass('snaps-active');
$('section#galeria').addClass('snaps-active');
if (scroll >= ($("section#galeria").offset().top + (0.5 * height_check))) {
$('section#galeria').removeClass('snaps-active');
}
}
});
}
});
});
});
</script>