Function HasRoadTypeAvail

src/road.cpp:123–145

* Finds out, whether given company has a given RoadType available for construction. * @param company ID of company * @param roadtypet RoadType to test * @return true if company has the requested RoadType available */

 * @return true if company has the requested RoadType available
 */
bool HasRoadTypeAvail(const CompanyID company, RoadType roadtype)
{
	if (company == OWNER_DEITY || company == OWNER_TOWN || _game_mode == GM_EDITOR || _generating_world) {
		const RoadTypeInfo *rti = GetRoadTypeInfo(roadtype);
		if (rti->label == 0) return false;

		/* Not yet introduced at this date. */
		if (IsInsideMM(rti->introduction_date, 0, CalendarTime::MAX_DATE.base()) && rti->introduction_date > TimerGameCalendar::date) return false;

		/*
		 * Do not allow building hidden road types, except when a town may build it.
		 * The GS under deity mode, as well as anybody in the editor builds roads that are
		 * owned by towns. So if a town may build it, it should be buildable by them too.
		 */
		return !rti->flags.Test( RoadTypeFlag::Hidden) || rti->flags.Test( RoadTypeFlag::TownBuild);
	} else {
		const Company *c = Company::GetIfValid(company);
		if (c == nullptr) return false;
		RoadTypes avail = c->avail_roadtypes;
		avail.Reset(_roadtypes_hidden_mask);
		return avail.Test(roadtype);
	}
}

/**
 * Test if any buildable RoadType is available for a company.