Method updateRail

src/OpenLoco/src/Vehicles/Vehicle1.cpp:158–247

0x004A97A6

    // 0x004A97A6
    bool Vehicle1::updateRail()
    {
        Vehicle train{ head };
        uint16_t curveSpeedFraction = std::numeric_limits<uint16_t>::max();
        Speed16 newTargetSpeed = kSpeed16Max;
        bool isOnRackRail = false;
        if (!train.head->hasVehicleFlags(VehicleFlags::manualControl))
        {
            RoutingManager::RingView ring(routingHandle);
            for (auto iter = ring.rbegin(); iter != ring.rend(); ++iter)
            {
                auto res = RoutingManager::getRouting(*iter);
                isOnRackRail |= (res & (1U << 13)) != 0; // rackrail
                uint8_t trackId = (res >> 3) & 0x3F;
                curveSpeedFraction = std::min(curveSpeedFraction, World::TrackData::getTrackMiscData(trackId).curveSpeedFraction);
                if (res & (1U << 12))
                {
                    const auto* bridgeObj = ObjectManager::get<BridgeObject>((res & 0xE00) >> 9);
                    if (bridgeObj->maxSpeed != kSpeed16Null)
                    {
                        newTargetSpeed = std::min(bridgeObj->maxSpeed, newTargetSpeed);
                    }
                }
            }
        }

        const auto* trackObj = ObjectManager::get<TrackObject>(trackType);
        const Speed32 fractionalSpeed = Speed32(static_cast<uint32_t>(curveSpeedFraction) * trackObj->curveSpeed.getRaw());
        newTargetSpeed = std::min(toSpeed16(fractionalSpeed + 1.0_mph), newTargetSpeed);

        if (train.head->has38Flags(Flags38::fasterAroundCurves))
        {
            newTargetSpeed += newTargetSpeed / 4;
            newTargetSpeed = std::min(trackObj->curveSpeed, newTargetSpeed);
        }

        const auto veh2MaxSpeed = [veh2 = train.veh2]() {
            if (veh2->has73Flags(Flags73::isBrokenDown))
            {
                return veh2->maxSpeed / 4;
            }
            return veh2->maxSpeed;
        }();

        newTargetSpeed = std::min(newTargetSpeed, veh2MaxSpeed);
        if (isOnRackRail)
        {
            newTargetSpeed = std::min(newTargetSpeed, train.veh2->rackRailMaxSpeed);
        }

        if (!train.head->hasVehicleFlags(VehicleFlags::manualControl))
        {
            // TODO: Original CS Bug. Fix when we diverge on replays
            // newTargetSpeed = std::min(newTargetSpeed, toSpeed16(speedFromDistanceInATick(var_3C)) + 5_mph);
            newTargetSpeed = std::min(newTargetSpeed, Speed16(static_cast<uint32_t>(var_3C) >> 15) + 5_mph);
        }

        if ((train.head->hasVehicleFlags(VehicleFlags::manualControl) && train.head->manualPower <= -20)