Method updateRoadTileOccupancy

src/OpenLoco/src/Vehicles/Vehicle.cpp:577–634

0x0047D959 ax : loc.x cx : loc.y dl : loc.z / 4 bp : trackAndDirection ebp : bp | (setOccupied << 31) returns dh : trackType

    // ebp : bp | (setOccupied << 31)
    // returns dh : trackType
    uint8_t VehicleBase::updateRoadTileOccupancy(const World::Pos3& loc, const TrackAndDirection::_RoadAndDirection rad, const bool setOccupied)
    {
        auto roadType = getTrackType();
        auto tile = World::TileManager::get(loc);
        for (auto& el : tile)
        {
            auto* elRoad = el.as<World::RoadElement>();
            if (elRoad == nullptr)
            {
                continue;
            }

            const auto heightDiff = std::abs(loc.z / 4 - elRoad->baseZ());
            if (heightDiff > 4)
            {
                continue;
            }

            if (elRoad->rotation() != rad.cardinalDirection())
            {
                continue;
            }

            if (elRoad->roadId() != rad.id())
            {
                continue;
            }

            if (elRoad->isAiAllocated())
            {
                continue;
            }

            const auto newLaneOccupation = World::TrackData::getRoadOccupationMask(rad._data >> 2) >> 4;
            if (setOccupied)
            {
                elRoad->setLaneOccupation(elRoad->laneOccupation() | newLaneOccupation);
            }
            else
            {
                elRoad->setLaneOccupation(elRoad->laneOccupation() & (~newLaneOccupation));
            }

            if (getTrackType() == 0xFF)
            {
                if (getGameState().roadObjectIdIsAnyRoadTypeCompatible & (1 << elRoad->roadObjectId()))
                {
                    elRoad->setUnk7_40(true);
                    roadType = elRoad->roadObjectId();
                }
            }
            else
            {
                roadType = getTrackType();
            }
        }
        return roadType;
    }