// 滚动到指定位置---begin
function getscrolltop() {
    return (document.scrollingelement && document.scrollingelement.scrolltop) ||
        document.documentelement.scrolltop ||
        document.body.scrolltop;
}

function setscrolltop(st) {
    if (!st) st = 0;
    document.documentelement.scrolltop = document.body.scrolltop = st;
}

function scrolltop(scrolltop, time) {
    scrolltop = scrolltop ? scrolltop : 0;
    time = time ? time : 500;
    const cubic = function (value) {
        return math.pow(value, 3)
    };
    const easeinoutcubic = function (value) {
        return value < 0.5 ? cubic(value * 2) / 2 : 1 - cubic((1 - value) * 2) / 2
    }
    const begintime = date.now();
    const beginvalue = getscrolltop();
    const raf = window.requestanimationframe || (function (func) {
        return settimeout(func, 16)
    });
    const framefunc = function () {
        if (isnan(+time) || +time === 0) {
            setscrolltop(scrolltop);
            return;
        }
        const progress = (date.now() - begintime) / time;
        if (progress < 1) {
            setscrolltop(
                scrolltop + (beginvalue - scrolltop) * (1 - easeinoutcubic(progress))
            );
            raf(framefunc);
        } else {
            setscrolltop(scrolltop);
        }
    };
    raf(framefunc);
};

/** 获取指定元素距离页面顶部距离 */
function getelementtopagetop(el) {
	if(el.parentelement) {
	  return getelementtopagetop(el.parentelement) + el.offsettop
	}
	return el.offsettop
}
/** 获取指定元素高度 */
function getelementheight(el) {
    return el.clientheight;
}

function playfirstvideo() {
    var videocontain = $($('.index-top-banner .swiper-slide')[0]);
    var curvideo = videocontain.find('video');
    if (curvideo.length) {
        curvideo.trigger('play');
    }
}