百度地图（BD-09）坐标系和高德（GCJ-02）坐标系的相互转换

php https://blog.csdn.net/ansinjay/article/details/89225977
c https://www.csdn.net/tags/OtDaEg1sOTQ2MjktYmxvZwO0O0OO0O0O.html
javascript https://blog.51cto.com/u_13685327/2097292