// 计算两点之间直线距离 export const algorithm = (point1, point2)=> { let [x1, y1] = point1; let [x2, y2] = point2; let Lat1 = rad(x1); // 纬度 let Lat2 = rad(x2); let a = Lat1 - Lat2;// 两点纬度之差 let b = rad(y1) - rad(y2); // 经度之差 let s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) + Math.cos(Lat1) * Math.cos(Lat2) * Math.pow(Math.sin(b / 2), 2))); // 计算两点距离的公式 s = s * 6378137.0;// 弧长等于弧度乘地球半径(半径为米) s = Math.round(s * 10000) / 10000;// 精确距离的数值 return s; } // 角度转换成弧度 const rad =(d) =>{ return d * Math.PI / 180.00; }; /** * 判断经纬度是否超出中国境内 */ export function isLocationOutOfChina(latitude, longitude) { if (longitude < 72.004 || longitude > 137.8347 || latitude < 0.8293 || latitude > 55.8271) return true; return false; } /** * 将WGS-84(国际标准)转为GCJ-02(火星坐标): */ export function transformFromWGSToGCJ(latitude, longitude) { let lat = ""; let lon = ""; let ee = 0.00669342162296594323; let a = 6378245.0; let pi = 3.14159265358979324; if (isLocationOutOfChina(latitude, longitude)) { lat = latitude; lon = longitude; } else { let adjustLat = transformLatWithXY(longitude - 105.0, latitude - 35.0); let adjustLon = transformLonWithXY(longitude - 105.0, latitude - 35.0); let radLat = latitude / 180.0 * pi; let magic = Math.sin(radLat); magic = 1 - ee * magic * magic; let sqrtMagic = Math.sqrt(magic); adjustLat = (adjustLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi); adjustLon = (adjustLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi); latitude = latitude + adjustLat; longitude = longitude + adjustLon; } return { latitude: latitude, longitude: longitude }; } /** * 将GCJ-02(火星坐标)转为百度坐标: */ export function transformFromGCJToBaidu(latitude, longitude) { let pi = 3.14159265358979324 * 3000.0 / 180.0; let z = Math.sqrt(longitude * longitude + latitude * latitude) + 0.00002 * Math.sin(latitude * pi); let theta = Math.atan2(latitude, longitude) + 0.000003 * Math.cos(longitude * pi); let a_latitude = (z * Math.sin(theta) + 0.006); let a_longitude = (z * Math.cos(theta) + 0.0065); return { latitude: a_latitude, longitude: a_longitude }; } /** * 将百度坐标转为GCJ-02(火星坐标): */ export function transformFromBaiduToGCJ(latitude, longitude) { let xPi = 3.14159265358979323846264338327950288 * 3000.0 / 180.0; let x = longitude - 0.0065; let y = latitude - 0.006; let z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * xPi); let theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * xPi); let a_latitude = z * Math.sin(theta); let a_longitude = z * Math.cos(theta); return { latitude: a_latitude, longitude: a_longitude }; } /** * 将GCJ-02(火星坐标)转为WGS-84: */ export function transformFromGCJToWGS({latitude, longitude}) { let threshold = 0.00001; // The boundary let minLat = latitude - 0.5; let maxLat = latitude + 0.5; let minLng = longitude - 0.5; let maxLng = longitude + 0.5; let delta = 1; let maxIteration = 30; let success = false while (success == false) { let leftBottom = transformFromWGSToGCJ(minLat, minLng); let rightBottom = transformFromWGSToGCJ(minLat, maxLng); let leftUp = transformFromWGSToGCJ(maxLat, minLng); let midPoint = transformFromWGSToGCJ((minLat + maxLat) / 2, (minLng + maxLng) / 2); delta = Math.abs(midPoint.latitude - latitude) + Math.abs(midPoint.longitude - longitude); if (maxIteration-- <= 0 || delta <= threshold) { return { latitude: (minLat + maxLat) / 2, longitude: (minLng + maxLng) / 2 }; } if (isContains({ latitude: latitude, longitude: longitude }, leftBottom, midPoint)) { maxLat = (minLat + maxLat) / 2; maxLng = (minLng + maxLng) / 2; } else if (isContains({ latitude: latitude, longitude: longitude }, rightBottom, midPoint)) { maxLat = (minLat + maxLat) / 2; minLng = (minLng + maxLng) / 2; } else if (isContains({ latitude: latitude, longitude: longitude }, leftUp, midPoint)) { minLat = (minLat + maxLat) / 2; maxLng = (minLng + maxLng) / 2; } else { minLat = (minLat + maxLat) / 2; minLng = (minLng + maxLng) / 2; } } } export function toPointWkt(location){ let {longitude,latitude} = location return "POINT(" + longitude + " " + latitude + ")" } export function pointWktToLocation(wkt){ let start = wkt.indexOf("(") let end = wkt.indexOf(")") let arr = wkt.substring(start + 1,end).trim().split(" ") return {longitude:parseFloat(arr[0]),latitude:parseFloat(arr[1])} } export function isContains(point, p1, p2) { return (point.latitude >= Math.min(p1.latitude, p2.latitude) && point.latitude <= Math.max(p1.latitude, p2.latitude)) && (point.longitude >= Math.min(p1.longitude, p2.longitude) && point.longitude <= Math.max(p1.longitude, p2.longitude)); } export function transformLatWithXY(x, y) { let pi = 3.14159265358979324; let lat = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x)); lat += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0; lat += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0; lat += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0; return lat; } export function transformLonWithXY(x, y) { let pi = 3.14159265358979324; let lon = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x)); lon += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0; lon += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0; lon += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0; return lon; } //检查视野范围是否超过了bbox export function checkRegion(bbox,region){ if(bbox.northeast.latitude < region.northeast.latitude ){ return true; } if(bbox.northeast.longitude < region.northeast.longitude ){ return true; } if( bbox.southwest.latitude > region.southwest.latitude ){ return true; } if(bbox.southwest.longitude > region.southwest.longitude ){ return true; } return false }