Function TrainApproachingCrossing

src/train_cmd.cpp:1732–1749

* Finds a vehicle approaching rail-road crossing * @param tile tile to test * @return true if a vehicle is approaching the crossing * @pre tile is a rail-road crossing */

 * @pre tile is a rail-road crossing
 */
static bool TrainApproachingCrossing(TileIndex tile)
{
	assert(IsLevelCrossingTile(tile));

	DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
	TileIndex tile_from = tile + TileOffsByDiagDir(dir);

	if (HasVehicleOnTile(tile_from, [&](const Vehicle *v) {
			return TrainApproachingCrossingEnum(v, tile);
		})) return true;

	dir = ReverseDiagDir(dir);
	tile_from = tile + TileOffsByDiagDir(dir);

	return HasVehicleOnTile(tile_from, [&](const Vehicle *v) {
		return TrainApproachingCrossingEnum(v, tile);
	});
}

/**
 * Check if a level crossing should be barred.