osrm-backend/include/extractor/turn_instructions.hpp

#ifndef TURN_INSTRUCTIONS_HPP
#define TURN_INSTRUCTIONS_HPP

namespace osrm
{
namespace extractor
{

enum class TurnInstruction : unsigned char
{
    NoTurn = 0,
    GoStraight,
    TurnSlightRight,
    TurnRight,
    TurnSharpRight,
    UTurn,
    TurnSharpLeft,
    TurnLeft,
    TurnSlightLeft,
    ReachViaLocation,
    HeadOn,
    EnterRoundAbout,
    LeaveRoundAbout,
    StayOnRoundAbout,
    StartAtEndOfStreet,
    ReachedYourDestination,
    EnterAgainstAllowedDirection,
    LeaveAgainstAllowedDirection,
    InverseAccessRestrictionFlag = 127,
    AccessRestrictionFlag = 128,
    AccessRestrictionPenalty = 129
};

struct TurnInstructionsClass
{
    TurnInstructionsClass() = delete;
    TurnInstructionsClass(const TurnInstructionsClass &) = delete;

    static inline TurnInstruction GetTurnDirectionOfInstruction(const double angle)
    {
        if (angle >= 23 && angle < 67)
        {
            return TurnInstruction::TurnSharpRight;
        }
        if (angle >= 67 && angle < 113)
        {
            return TurnInstruction::TurnRight;
        }
        if (angle >= 113 && angle < 158)
        {
            return TurnInstruction::TurnSlightRight;
        }
        if (angle >= 158 && angle < 202)
        {
            return TurnInstruction::GoStraight;
        }
        if (angle >= 202 && angle < 248)
        {
            return TurnInstruction::TurnSlightLeft;
        }
        if (angle >= 248 && angle < 292)
        {
            return TurnInstruction::TurnLeft;
        }
        if (angle >= 292 && angle < 336)
        {
            return TurnInstruction::TurnSharpLeft;
        }
        return TurnInstruction::UTurn;
    }

    static inline bool TurnIsNecessary(const TurnInstruction turn_instruction)
    {
        if (TurnInstruction::NoTurn == turn_instruction ||
            TurnInstruction::StayOnRoundAbout == turn_instruction)
        {
            return false;
        }
        return true;
    }
};

}
}

#endif /* TURN_INSTRUCTIONS_HPP */