building-materials-shop-uniapp-241014/utils/position.js

import config from '../config.js'

/**
 * 计算两点之间的距离
 * @param {number} lat1 地点1精度
 * @param {number} lon1 地点1维度
 * @param {number} lat2 地点2精度
 * @param {number} lon2 地点2维度
 * @param {number} fixed 保留几位小数,默认0,单位km
 */
function calculateDistance(lat1, lon1, lat2, lon2, fixed = 0) { //计算两点距离
	let distance = 0
	if (!lat2 || !lon2) return distance
	//先强制转换一下(后端给的字符串)
	lat1 = parseFloat(lat1)
	lon1 = parseFloat(lon1)
	lat2 = parseFloat(lat2)
	lon2 = parseFloat(lon2)
	// 将角度转换为弧度
	const R = 6371; // 地球半径，单位公里  
	const dLat = (lat2 - lat1) * Math.PI / 180;
	const dLon = (lon2 - lon1) * Math.PI / 180;
	lat1 = lat1 * Math.PI / 180;
	lat2 = lat2 * Math.PI / 180;
	// Haversine公式  
	const a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
		Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);
	const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
	// 计算距离  
	distance = R * c;
	return distance.toFixed(fixed)
}



export default {
	calculateDistance, //计算两点距离
}