China GPS Convertion In iOS Development Sep 1st, 2015 8:40 pm | Comments // // ChinaGPS.swift // LocationTraker // // Created by larryhou on 28/7/2015. // Copyright © 2015 larryhou. All rights reserved. // import Foundation import CoreLocation class ChinaGPS { struct GPSLocation { var lon, lat:Double } static private let pi = 3.14159265358979324 static private let x_pi = pi * 3000.0 / 180.0 // // Krasovsky 1940 // // a = 6378245.0, 1/f = 298.3 // b = a * (1 - f) // ee = (a^2 - b^2) / a^2; static private let a = 6378245.0 static private let ee = 0.00669342162296594323 private class func encrypt_lat(x:Double, y:Double) -> Double { var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y ret += 0.2 * sqrt(abs(x)) ret += (20.0 * sin(6.0 * x * pi) + 20.0 * sin(2.0 * x * pi)) * 2.0 / 3.0 ret += (20.0 * sin(y * pi) + 40.0 * sin(y / 3.0 * pi)) * 2.0 / 3.0 ret += (160.0 * sin(y / 12.0 * pi) + 320 * sin(y * pi / 30.0)) * 2.0 / 3.0 return ret } private class func encrypt_lon(x:Double, y:Double) -> Double { var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y ret += 0.1 * sqrt(abs(x)) ret += (20.0 * sin(6.0 * x * pi) + 20.0 * sin(2.0 * x * pi)) * 2.0 / 3.0 ret += (20.0 * sin(x * pi) + 40.0 * sin(x / 3.0 * pi)) * 2.0 / 3.0 ret += (150.0 * sin(x / 12.0 * pi) + 300.0 * sin(x / 30.0 * pi)) * 2.0 / 3.0 return ret } private class func outOfChina(lat:Double, lon:Double) -> Bool { if lon < 72.004 || lon > 137.8347 { return true } if lat < 0.8293 || lat > 55.8271 { return true } return false } /// /// WGS-84 到 GCJ-02 的转换 /// class func encrypt_WGS_2_GCJ(loc:GPSLocation) -> GPSLocation { if outOfChina(loc.lat, lon: loc.lon) { return loc } var lat = encrypt_lat(loc.lon - 105.0, y: loc.lat - 35.0) var lon = encrypt_lon(loc.lon - 105.0, y: loc.lat - 35.0) let radian = loc.lat / 180.0 * pi let magic = 1 - ee * sin(radian) * sin(radian) let magic_2 = sqrt(magic) lat = (lat * 180.0) / ((a * (1 - ee)) / (magic * magic_2) * pi) lon = (lon * 180.0) / (a / magic_2 * cos(radian) * pi) return GPSLocation(lon: loc.lon + lon, lat: loc.lat + lat) } class func encrypt_WGS_2_GCJ(latitude latitude:Double, longitude:Double) -> CLLocation { let loc = GPSLocation(lon: longitude, lat: latitude) let ret = encrypt_WGS_2_GCJ(loc) return CLLocation(latitude: ret.lat, longitude: ret.lon) } class func encrypt_WGS_2_GCJ(latitude latitude:Double, longitude:Double) -> CLLocationCoordinate2D { let loc = GPSLocation(lon: longitude, lat: latitude) let ret = encrypt_WGS_2_GCJ(loc) return CLLocationCoordinate2D(latitude: ret.lat, longitude: ret.lon) } /// /// GCJ-02 坐标转换成 BD-09 坐标 /// class func baidu_encrypt(loc:GPSLocation) -> GPSLocation { let x = loc.lon, y = loc.lat let z = sqrt(x * x + y * y) + 0.00002 * sin(y * x_pi) let theta = atan2(y, x) + 0.000003 * cos(x * x_pi) return GPSLocation(lon:z * cos(theta) + 0.0065, lat:z * sin(theta) + 0.006) } class func baidu_encrypt(latitude latitude:Double, longitude:Double) -> CLLocation { let loc = GPSLocation(lon: longitude, lat: latitude) let ret = baidu_encrypt(loc) return CLLocation(latitude: ret.lat, longitude: ret.lon) } /// /// BD-09 坐标转换成 GCJ-02坐标 /// class func baidu_decrypt(loc:GPSLocation) -> GPSLocation { let x = loc.lon - 0.0065, y = loc.lat - 0.006 let z = sqrt(x * x + y * y) - 0.00002 * sin(y * x_pi) let theta = atan2(y, x) - 0.000003 * cos(x * x_pi) return GPSLocation(lon:z * cos(theta), lat:z * sin(theta)) } class func baidu_decrypt(latitude latitude:Double, longitude:Double) -> CLLocation { let loc = GPSLocation(lon: longitude, lat: latitude) let ret = baidu_decrypt(loc) return CLLocation(latitude: ret.lat, longitude: ret.lon) } }