osrm-backend/include/util/coordinate_calculation.hpp

#ifndef COORDINATE_CALCULATION
#define COORDINATE_CALCULATION

#include "util/coordinate.hpp"

#include <string>
#include <utility>

namespace osrm
{
namespace util
{

const constexpr long double RAD = 0.017453292519943295769236907684886;
// earth radius varies between 6,356.750-6,378.135 km (3,949.901-3,963.189mi)
// The IUGG value for the equatorial radius is 6378.137 km (3963.19 miles)
const constexpr long double EARTH_RADIUS = 6372797.560856;

namespace coordinate_calculation
{

double haversineDistance(const Coordinate first_coordinate, const Coordinate second_coordinate);

double greatCircleDistance(const Coordinate first_coordinate, const Coordinate second_coordinate);

double perpendicularDistance(const Coordinate segment_source,
                             const Coordinate segment_target,
                             const Coordinate query_location);

double perpendicularDistance(const Coordinate segment_source,
                             const Coordinate segment_target,
                             const Coordinate query_location,
                             Coordinate &nearest_location,
                             double &ratio);

double perpendicularDistanceFromProjectedCoordinate(
    const Coordinate segment_source,
    const Coordinate segment_target,
    const Coordinate query_location,
    const std::pair<double, double> projected_xy_coordinate);

double perpendicularDistanceFromProjectedCoordinate(
    const Coordinate segment_source,
    const Coordinate segment_target,
    const Coordinate query_location,
    const std::pair<double, double> projected_xy_coordinate,
    Coordinate &nearest_location,
    double &ratio);

double degToRad(const double degree);
double radToDeg(const double radian);

double bearing(const Coordinate first_coordinate, const Coordinate second_coordinate);

// Get angle of line segment (A,C)->(C,B)
double computeAngle(const Coordinate first, const Coordinate second, const Coordinate third);

namespace mercator
{
FloatLatitude yToLat(const double value);
double latToY(const FloatLatitude latitude);
} // ns mercator
} // ns coordinate_calculation
} // ns util
} // ns osrm

#endif // COORDINATE_CALCULATION