Function IsPossibleCrossing

src/road.cpp:45–51

* Return if the tile is a valid tile for a crossing. * * @param tile the current tile * @param ax the axis of the road over the rail * @return true if it is a valid tile */

 * @return true if it is a valid tile
 */
static bool IsPossibleCrossing(const TileIndex tile, Axis ax)
{
	return (IsTileType(tile, MP_RAILWAY) &&
		GetRailTileType(tile) == RailTileType::Normal &&
		GetTrackBits(tile) == (ax == AXIS_X ? TRACK_BIT_Y : TRACK_BIT_X) &&
		std::get<0>(GetFoundationSlope(tile)) == SLOPE_FLAT);
}

/**
 * Clean up unnecessary RoadBits of a planned tile.