Function TrainCheckIfLineEnds

src/train_cmd.cpp:3896–3944

* Checks for line end. Also, bars crossing at next tile if needed * * @param v vehicle we are checking * @param reverse Set to false to not execute the vehicle reversing. This does not change any other logic. * @return true iff we did NOT have to reverse */

 * @return true iff we did NOT have to reverse
 */
static bool TrainCheckIfLineEnds(Train *v, bool reverse)
{
	/* First, handle broken down train */

	int t = v->breakdown_ctr;
	if (t > 1) {
		v->vehstatus.Set(VehState::TrainSlowing);

		uint16_t break_speed = _breakdown_speeds[GB(~t, 4, 4)];
		if (break_speed < v->cur_speed) v->cur_speed = break_speed;
	} else {
		v->vehstatus.Reset(VehState::TrainSlowing);
	}

	if (!TrainCanLeaveTile(v)) return true;

	/* Determine the non-diagonal direction in which we will exit this tile */
	DiagDirection dir = VehicleExitDir(v->direction, v->track);
	/* Calculate next tile */
	TileIndex tile = v->tile + TileOffsByDiagDir(dir);

	/* Determine the track status on the next tile */
	TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
	TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);

	TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
	TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;

	/* We are sure the train is not entering a depot, it is detected above */

	/* mask unreachable track bits if we are forbidden to do 90deg turns */
	TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
	if (Rail90DegTurnDisallowed(GetTileRailType(v->tile), GetTileRailType(tile))) {
		bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
	}

	/* no suitable trackbits at all || unusable rail (wrong type or owner) */
	if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
		return TrainApproachingLineEnd(v, false, reverse);
	}

	/* approaching red signal */
	if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);

	/* approaching a rail/road crossing? then make it red */
	if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);

	return true;
}


static bool TrainLocoHandler(Train *v, bool mode)