Function UpdateLevelCrossingTile

src/train_cmd.cpp:1769–1783

* Sets a level crossing tile to the correct state. * @param tile Tile to update. * @param sound Should we play sound? * @param force_barred Should we set the crossing to barred? * @pre tile is a rail-road crossing. */

 * @pre tile is a rail-road crossing.
 */
static void UpdateLevelCrossingTile(TileIndex tile, bool sound, bool force_barred)
{
	assert(IsLevelCrossingTile(tile));
	bool set_barred;

	/* We force the crossing to be barred when an adjacent crossing is barred, otherwise let it decide for itself. */
	set_barred = force_barred || CheckLevelCrossing(tile);

	/* The state has changed */
	if (set_barred != IsCrossingBarred(tile)) {
		if (set_barred && sound && _settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
		SetCrossingBarred(tile, set_barred);
		MarkTileDirtyByTile(tile);
	}
}

/**
 * Update a level crossing to barred or open (crossing may include multiple adjacent tiles).