osrm-backend/include/engine/polyline_compressor.hpp

#ifndef POLYLINECOMPRESSOR_H_
#define POLYLINECOMPRESSOR_H_

#include "osrm/coordinate.hpp"

#include <string>
#include <vector>

namespace osrm
{
namespace engine
{
namespace detail
{
    constexpr double POLYLINE_PECISION = 1e5;
    constexpr double COORDINATE_TO_POLYLINE = POLYLINE_PECISION / COORDINATE_PRECISION;
    constexpr double POLYLINE_TO_COORDINATE = COORDINATE_PRECISION / POLYLINE_PECISION;
}

using CoordVectorForwardIter = std::vector<FixedPointCoordinate>::const_iterator;
// Encodes geometry into polyline format.
// See: https://developers.google.com/maps/documentation/utilities/polylinealgorithm
std::string encodePolyline(CoordVectorForwardIter begin, CoordVectorForwardIter end);

// Decodes geometry from polyline format
// See: https://developers.google.com/maps/documentation/utilities/polylinealgorithm
std::vector<util::FixedPointCoordinate> decodePolyline(const std::string &polyline);
}
}

#endif /* POLYLINECOMPRESSOR_H_ */