osrm-backend/include/extractor/guidance/turn_instruction.hpp

#ifndef OSRM_GUIDANCE_TURN_INSTRUCTION_HPP_
#define OSRM_GUIDANCE_TURN_INSTRUCTION_HPP_

#include <cstdint>

#include <boost/assert.hpp>

#include "extractor/guidance/roundabout_type.hpp"

namespace osrm
{
namespace extractor
{
namespace guidance
{

namespace detail
{
// inclusive bounds for turn modifiers
const constexpr uint8_t num_direction_modifiers = 8;
} // detail

// direction modifiers based on angle
namespace DirectionModifier
{
typedef std::uint8_t Enum;
const constexpr Enum UTurn = 0;
const constexpr Enum SharpRight = 1;
const constexpr Enum Right = 2;
const constexpr Enum SlightRight = 3;
const constexpr Enum Straight = 4;
const constexpr Enum SlightLeft = 5;
const constexpr Enum Left = 6;
const constexpr Enum SharpLeft = 7;
}

namespace TurnType
{
typedef std::uint8_t Enum;
const constexpr Enum Invalid = 0;                      // no valid turn instruction
const constexpr Enum NewName = 1;                      // no turn, but name changes
const constexpr Enum Continue = 2;                     // remain on a street
const constexpr Enum Turn = 3;                         // basic turn
const constexpr Enum Merge = 4;                        // merge onto a street
const constexpr Enum OnRamp = 5;                       // special turn (highway ramp on-ramps)
const constexpr Enum OffRamp = 6;                      // special turn, highway exit
const constexpr Enum Fork = 7;                         // fork road splitting up
const constexpr Enum EndOfRoad = 8;                    // T intersection
const constexpr Enum Notification = 9;                 // Travel Mode Changes, Restrictions apply...
const constexpr Enum EnterRoundabout = 10;             // Entering a small Roundabout
const constexpr Enum EnterAndExitRoundabout = 11;      // Touching a roundabout
const constexpr Enum EnterRotary = 12;                 // Enter a rotary
const constexpr Enum EnterAndExitRotary = 13;          // Touching a rotary
const constexpr Enum EnterRoundaboutIntersection = 14; // Entering a small Roundabout
const constexpr Enum EnterAndExitRoundaboutIntersection = 15; // Touching a roundabout

// Values below here are silent instructions
const constexpr Enum NoTurn = 16;                // end of segment without turn/middle of a segment
const constexpr Enum Suppressed = 17;            // location that suppresses a turn
const constexpr Enum EnterRoundaboutAtExit = 18; // Entering a small Roundabout at a countable exit
const constexpr Enum ExitRoundabout = 19;        // Exiting a small Roundabout
const constexpr Enum EnterRotaryAtExit = 20;     // Enter A Rotary at a countable exit
const constexpr Enum ExitRotary = 21;            // Exit a rotary
const constexpr Enum EnterRoundaboutIntersectionAtExit =
    22; // Entering a small Roundabout at a countable exit
const constexpr Enum ExitRoundaboutIntersection = 23; // Exiting a small Roundabout
const constexpr Enum StayOnRoundabout = 24; // Continue on Either a small or a large Roundabout
const constexpr Enum Sliproad =
    25; // Something that looks like a ramp, but is actually just a small sliproad
}

// turn angle in 1.40625 degree -> 128 == 180 degree
struct TurnInstruction
{
    TurnInstruction(const TurnType::Enum type = TurnType::Invalid,
                    const DirectionModifier::Enum direction_modifier = DirectionModifier::Straight)
        : type(type), direction_modifier(direction_modifier)
    {
    }

    TurnType::Enum type : 5;
    DirectionModifier::Enum direction_modifier : 3;

    static TurnInstruction INVALID()
    {
        return TurnInstruction(TurnType::Invalid, DirectionModifier::UTurn);
    }

    static TurnInstruction NO_TURN()
    {
        return TurnInstruction(TurnType::NoTurn, DirectionModifier::UTurn);
    }

    static TurnInstruction REMAIN_ROUNDABOUT(const RoundaboutType,
                                             const DirectionModifier::Enum modifier)
    {
        return TurnInstruction(TurnType::StayOnRoundabout, modifier);
    }

    static TurnInstruction ENTER_ROUNDABOUT(const RoundaboutType roundabout_type,
                                            const DirectionModifier::Enum modifier)
    {
        const constexpr TurnType::Enum enter_instruction[] = {
            TurnType::Invalid,
            TurnType::EnterRoundabout,
            TurnType::EnterRotary,
            TurnType::EnterRoundaboutIntersection};
        return {enter_instruction[static_cast<int>(roundabout_type)], modifier};
    }

    static TurnInstruction EXIT_ROUNDABOUT(const RoundaboutType roundabout_type,
                                           const DirectionModifier::Enum modifier)
    {
        const constexpr TurnType::Enum exit_instruction[] = {TurnType::Invalid,
                                                             TurnType::ExitRoundabout,
                                                             TurnType::ExitRotary,
                                                             TurnType::ExitRoundaboutIntersection};
        return {exit_instruction[static_cast<int>(roundabout_type)], modifier};
    }

    static TurnInstruction ENTER_AND_EXIT_ROUNDABOUT(const RoundaboutType roundabout_type,
                                                     const DirectionModifier::Enum modifier)
    {
        const constexpr TurnType::Enum exit_instruction[] = {
            TurnType::Invalid,
            TurnType::EnterAndExitRoundabout,
            TurnType::EnterAndExitRotary,
            TurnType::EnterAndExitRoundaboutIntersection};
        return {exit_instruction[static_cast<int>(roundabout_type)], modifier};
    }

    static TurnInstruction ENTER_ROUNDABOUT_AT_EXIT(const RoundaboutType roundabout_type,
                                                    const DirectionModifier::Enum modifier)
    {
        const constexpr TurnType::Enum enter_instruction[] = {
            TurnType::Invalid,
            TurnType::EnterRoundaboutAtExit,
            TurnType::EnterRotaryAtExit,
            TurnType::EnterRoundaboutIntersectionAtExit};
        return {enter_instruction[static_cast<int>(roundabout_type)], modifier};
    }

    static TurnInstruction SUPPRESSED(const DirectionModifier::Enum modifier)
    {
        return {TurnType::Suppressed, modifier};
    }
};

static_assert(sizeof(TurnInstruction) == 1, "TurnInstruction does not fit one byte");

inline bool operator!=(const TurnInstruction lhs, const TurnInstruction rhs)
{
    return lhs.type != rhs.type || lhs.direction_modifier != rhs.direction_modifier;
}

inline bool operator==(const TurnInstruction lhs, const TurnInstruction rhs)
{
    return lhs.type == rhs.type && lhs.direction_modifier == rhs.direction_modifier;
}

} // namespace guidance
} // namespace extractor
} // namespace osrm

#endif // OSRM_GUIDANCE_TURN_INSTRUCTION_HPP_