Function ResearchDetermineFirstOfType

src/openrct2/management/Research.cpp:1066–1124

}

void ResearchDetermineFirstOfType()
{
    auto& gameState = getGameState();
    _seenRideType.reset();

    for (const auto& researchItem : gameState.researchItemsInvented)
    {
        if (researchItem.type != Research::EntryType::ride)
            continue;

        auto rideType = researchItem.baseRideType;
        if (rideType >= RIDE_TYPE_COUNT)
            continue;

        const auto& rtd = GetRideTypeDescriptor(rideType);
        if (rtd.flags.has(RtdFlag::listVehiclesSeparately))
            continue;

        // The last research item will also be present in gameState.researchItemsInvented.
        // Avoid marking its ride type as "invented" prematurely.
        if (gameState.researchLastItem.has_value() && !gameState.researchLastItem->isNull()
            && researchItem == gameState.researchLastItem.value())
            continue;

        // The next research item is (sometimes?) also present in gameState.researchItemsInvented, even though it isn't invented
        // yet(!)
        if (gameState.researchNextItem.has_value() && !gameState.researchNextItem->isNull()
            && researchItem == gameState.researchNextItem.value())
            continue;

        ResearchMarkRideTypeAsSeen(researchItem);
    }

    if (gameState.researchLastItem.has_value())
    {
        ResearchUpdateFirstOfType(&gameState.researchLastItem.value());
        ResearchMarkRideTypeAsSeen(gameState.researchLastItem.value());
    }
    if (gameState.researchNextItem.has_value())
    {
        ResearchUpdateFirstOfType(&gameState.researchNextItem.value());
        ResearchMarkRideTypeAsSeen(gameState.researchNextItem.value());
    }

    for (auto& researchItem : gameState.researchItemsUninvented)
    {
        // The next research item is (sometimes?) also present in gameState.researchItemsUninvented
        if (gameState.researchNextItem.has_value() && !gameState.researchNextItem->isNull()
            && researchItem.baseRideType == gameState.researchNextItem.value().baseRideType)
        {
            // Copy the "first of type" flag.
            researchItem.flags = gameState.researchNextItem->flags;
            continue;
        }

        ResearchUpdateFirstOfType(&researchItem);
        ResearchMarkRideTypeAsSeen(researchItem);
    }