Function defragmentTilePeriodic

src/OpenLoco/src/Map/TileManager.cpp:697–753

0x004613F0

    // 0x004613F0
    void defragmentTilePeriodic()
    {
        if (!Game::hasFlags(GameStateFlags::tileManagerLoaded))
        {
            return;
        }
        if (_disablePeriodicDefrag)
        {
            _disablePeriodicDefrag = false;
            return;
        }
        _disablePeriodicDefrag = false;

        const uint32_t searchStart = _periodicDefragStartTile + 1;
        for (auto i = 0U; i < kNumTiles; ++i)
        {
            const auto j = (i + searchStart) % kNumTiles;
            if (_tiles[j] != nullptr)
            {
                _periodicDefragStartTile = j;
                break;
            }
        }

        auto* firstTile = _tiles[_periodicDefragStartTile];
        auto* emptyTile = firstTile - 1;
        while (emptyTile != &_elements[0] && emptyTile->baseZ() == 0xFFU)
        {
            emptyTile--;
        }
        emptyTile++;
        if (emptyTile == firstTile)
        {
            return;
        }

        _tiles[_periodicDefragStartTile] = emptyTile;
        {
            auto* dest = emptyTile;
            auto* source = firstTile;
            do
            {
                *dest = *source;
                source->setBaseZ(0xFFU);
                source++;
            } while (!dest++->isLast());
        }

        // Its possible we have freed up elements at the end so this
        // looks to see if we should move the element end
        auto newEnd = _elementsEnd - 1;
        while (_elements[newEnd].baseZ() == 0xFFU)
        {
            newEnd--;
        }
        _elementsEnd = newEnd + 1;
    }