webMercator 坐标转换 像素坐标 ，地理坐标和地图坐标相互转换

 data 2018 7 12  by WJB

 

#include
#define MapLenght(level)   256*pow(2,(level))

#define WEBMERCATOR_256_MAP_LONG    20037508.342789

#define PI    3.141592653589793

#define WEBERCATOR_256_RESOLUTION(x) ((WEBMERCATOR_256_MAP_LONG * 2)/(256 * (2<<((x)-1))))

struct Point2D
{
    double x_;
    double y_;

    Point2D(double _x,double _y)
    {
        x_ = _x;
        y_ = _y;
    }
    Point2D()
    {
        x_ = 0;
        y_ = 0;
    }

};

Point2D qgs2map(const Point2D & qgs, int zoomLevel)

{

    Point2D mapPoint;

    double resolution = WEBERCATOR_256_RESOLUTION(zoomLevel);

    double x = (double)(-WEBMERCATOR_256_MAP_LONG + (qgs.x_*resolution));

    double y = (double)(WEBMERCATOR_256_MAP_LONG - (qgs.y_*resolution));

    mapPoint.x_=x;

    mapPoint.y_=y;

    return mapPoint;

}

// Moded by WJB 2018 07 12

//，地图坐标与地理坐标之间的转换函数.…

Point2D map211(const Point2D & map)

{

    Point2D geoPoint;

    double x = (double)(map.x_ / WEBMERCATOR_256_MAP_LONG * 180);

    double y = (double)(map.y_ / WEBMERCATOR_256_MAP_LONG * 180);

    y = (180 / PI)*(2 * atan(exp(y*PI / 180)) - PI / 2);

    geoPoint.x_ = x;

    geoPoint.y_ = y;

    return geoPoint;

}

Point2D map2qgs(const Point2D & map, int zoomLevel)

{

    //Moded bY WJB 2018 07 12 

    // 地图坐标与场景像素坐标之间的转换函数

    Point2D pixPoint;

    double resolution = WEBERCATOR_256_RESOLUTION(zoomLevel);

    double x = (double)((WEBMERCATOR_256_MAP_LONG + map.x_) / resolution);

    double y = (double)((WEBMERCATOR_256_MAP_LONG - map.y_) / resolution);

    pixPoint.x_ = x;

    pixPoint.y_ = y;

    return pixPoint;

}

Point2D ll2map(const Point2D & geo)

{

    //Moded by WJB 2018 07 12

    //地理坐标与地图坐标之间的转换函数

    Point2D mapPoint;

    double x = (double)(geo.x_ *WEBMERCATOR_256_MAP_LONG / 180);

    double y = (double)(log(tan(((90 + geo.y_)*PI / 360))) / (PI / 180));

    y = y*WEBMERCATOR_256_MAP_LONG / 180;

    mapPoint.x_ = x;

    mapPoint.y_ = y;

    return mapPoint;

}