Function paintTileElementsSetup

src/OpenLoco/src/Paint/PaintTile.cpp:221–254

Returns std::nullopt on no need to paint

    // Returns std::nullopt on no need to paint
    static std::optional<Ui::viewport_pos> paintTileElementsSetup(PaintSession& session, const World::Pos2& loc)
    {
        session.setSegmentsSupportHeight(SegmentFlags::all, std::numeric_limits<uint16_t>::max(), 0);
        session.setGeneralSupportHeight(std::numeric_limits<uint16_t>::max(), 0);
        session.resetTunnels();
        session.setUnkPosition(loc);
        session.setMapPosition(loc);

        session.setMaxHeight(loc);

        constexpr World::Pos2 kUnkOffsets[4] = {
            { 0, 0 },
            { 32, 0 },
            { 32, 32 },
            { 0, 32 },
        };

        const auto loc2 = loc + kUnkOffsets[session.getRotation()];
        const auto vpPos = World::gameToScreen(World::Pos3(loc2.x, loc2.y, 0), session.getRotation());
        paintConstructionArrow(session, loc2);

        if (vpPos.y + 52 <= session.getRenderTarget()->y)
        {
            return std::nullopt;
        }
        if (vpPos.y - session.getMaxHeight() > session.getRenderTarget()->y + session.getRenderTarget()->height)
        {
            return std::nullopt;
        }

        session.setEntityPosition(loc2);
        session.resetTileColumn({ vpPos.x, vpPos.y });
        return { vpPos };
    }

    static void paintTileElementsEndLoop(PaintSession& session, const World::TileElement& el)
    {