Function AddDateIntroducedRoadTypes

src/road.cpp:177–202

* Add the road types that are to be introduced at the given date. * @param rt Roadtype * @param current The currently available roadtypes. * @param date The date for the introduction comparisons. * @return The road types that should be available when date * introduced road types are taken into account as well. */

 *         introduced road types are taken into account as well.
 */
RoadTypes AddDateIntroducedRoadTypes(RoadTypes current, TimerGameCalendar::Date date)
{
	RoadTypes rts = current;

	for (RoadType rt = ROADTYPE_BEGIN; rt != ROADTYPE_END; rt++) {
		const RoadTypeInfo *rti = GetRoadTypeInfo(rt);
		/* Unused road type. */
		if (rti->label == 0) continue;

		/* Not date introduced. */
		if (!IsInsideMM(rti->introduction_date, 0, CalendarTime::MAX_DATE.base())) continue;

		/* Not yet introduced at this date. */
		if (rti->introduction_date > date) continue;

		/* Have we introduced all required roadtypes? */
		RoadTypes required = rti->introduction_required_roadtypes;
		if (!rts.All(required)) continue;

		rts.Set(rti->introduces_roadtypes);
	}

	/* When we added roadtypes we need to run this method again; the added
	 * roadtypes might enable more rail types to become introduced. */
	return rts == current ? rts : AddDateIntroducedRoadTypes(rts, date);
}

/**
 * Get the road types the given company can build.