lcoco/uni_modules/zebra-swiper/libs/update/updateSlidesProgress.js

export default function updateSlidesProgress(translate = this && this.translate || 0) {
	const swiper = this;
	const params = swiper.params;
	const {
		slides,
		rtlTranslate: rtl,
		snapGrid
	} = swiper;
	if (slides.length === 0) return;
	if (typeof slides[0].swiperSlideOffset === 'undefined' || typeof slides[slides.length - 1].swiperSlideOffset ===
		'undefined') swiper
		.updateSlidesOffset();
	let offsetCenter = -translate;
	if (rtl) offsetCenter = translate; // Visible Slides

	swiper.visibleSlidesIndexes = [];
	swiper.visibleSlides = [];
	
	// slides.forEach((item)=>)

	for (let i = 0; i < slides.length; i += 1) {
		const slide = slides[i];
		let slideOffset = slide.swiperSlideOffset;
		if (params.cssMode && params.centeredSlides) {
			slideOffset -= slides[0].swiperSlideOffset;
		}

		const slideProgress = (offsetCenter + (params.centeredSlides ? swiper.minTranslate() : 0) - slideOffset) / (
			slide.swiperSlideSize + params.spaceBetween);
		const originalSlideProgress = (offsetCenter - snapGrid[0] + (params.centeredSlides ? swiper.minTranslate() :
			0) - slideOffset) / (slide.swiperSlideSize + params.spaceBetween);
		const slideBefore = -(offsetCenter - slideOffset);
		const slideAfter = slideBefore + swiper.slidesSizesGrid[i];
		const isVisible = slideBefore >= 0 && slideBefore < swiper.size - 1 || slideAfter > 1 && slideAfter <= swiper
			.size || slideBefore <= 0 && slideAfter >= swiper.size;
		if (isVisible) {
			swiper.visibleSlides.push(slide);
			swiper.visibleSlidesIndexes.push(i);
			slides[i].addClass(params.slideVisibleClass);
		}

		slide.progress = rtl ? -slideProgress : slideProgress;
		slide.originalProgress = rtl ? -originalSlideProgress : originalSlideProgress;
	}
}