toys/gps/docs/source/coord/web_mercator.cpp

#include "geo/private/util/angle_util.h"
#include "geo/private/coord/web_mercator.h"

namespace ns
{
namespace geo
{

static double g_delta = 20037508.34 / 180;
static double g_1_delta = 180.0 / 20037508.34;
static double g_PI_180 = c_pi() / 180.0;
static double g_PI_360 = c_pi() / 360.0;

PointD lonLat2WebMercator(const PointD& lonLat)
{
    double x = lonLat.x * g_delta;
    double y = log(tan((90 + lonLat.y) * g_PI_360)) / g_PI_180;
    y = y * g_delta;
    return {x, y};
}

// Web墨卡托转经纬度
PointD webMercator2LonLat(const PointD& mercator)
{
    double x = mercator.x * g_1_delta;
    double y = mercator.y * g_1_delta;
    y = 180 * c_1_pi() * (2 * atan(exp(y * g_PI_180)) - c_pi_2());
    return {x, y};
}

} // namespace geo
} // namespace ns