Function getRoadProgressAtCursor

src/OpenLoco/src/Ui/Windows/Vehicle.cpp:4476–4506

0x004A43E4

        // 0x004A43E4
        static uint16_t getRoadProgressAtCursor(const Point& cursorLoc, Ui::Viewport& viewport, const RoadElement& roadElement, const World::Pos3& loc)
        {
            // Get the coordinates of the first tile of the possibly multi-tile road
            const auto& roadDataArr = World::TrackData::getRoadPiece(roadElement.roadId());
            const auto& roadData = roadDataArr[roadElement.sequenceIndex()];
            auto roadOffset2 = Math::Vector::rotate(World::Pos2(roadData.x, roadData.y), roadElement.rotation());
            auto roadOffset = World::Pos3(roadOffset2.x, roadOffset2.y, roadData.z);
            auto roadFirstTile = loc - roadOffset;

            // Get the movement info for this specific road id
            uint16_t trackAndDirection = roadElement.rotation() | (roadElement.roadId() << 3);
            const auto moveInfoArr = World::TrackData::getRoadPlacementSubPositon(trackAndDirection);

            // This iterates the movement info trying to find the distance along the road that is as close as possible
            // to the cursors location.
            int32_t bestDistance = std::numeric_limits<int32_t>::max();
            uint16_t bestProgress = 0;
            for (const auto& moveInfo : moveInfoArr)
            {
                auto potentialLoc = roadFirstTile + moveInfo.loc;
                auto viewPos = World::gameToScreen(potentialLoc, viewport.getRotation());
                auto uiPos = viewport.viewportToScreen(viewPos);
                auto distance = Math::Vector::manhattanDistance2D(uiPos, cursorLoc);
                if (distance < bestDistance)
                {
                    bestDistance = distance;
                    bestProgress = std::distance(&*moveInfoArr.begin(), &moveInfo);
                }
            }
            return bestProgress;
        }

        // 0x00478415
        static std::optional<GameCommands::VehiclePlacementArgs> getRoadAtCursor(const int16_t x, const int16_t y)