/**
 * Returns the owner of a tile
 *
 * This function returns the owner of a tile. This cannot used
 * for tiles which type is one of MP_HOUSE, MP_VOID and MP_INDUSTRY
 * as no company owned any of these buildings.
 *
 * @param tile The tile to check
 * @return The owner of the tile
 * @pre IsValidTile(tile)
 * @pre The type of the tile must not be MP_HOUSE and MP_INDUSTRY
 */
static inline Owner GetTileOwner(TileIndex tile)
{
	assert(IsValidTile(tile));
	assert(!IsTileType(tile, MP_HOUSE));
	assert(!IsTileType(tile, MP_INDUSTRY));
	if ((IsTileType(tile, MP_STATION) || IsTileType(tile, MP_WATER) || IsTileType(tile, MP_OBJECT))) {
		Owner co = (Owner)GB(_m[tile].m1, 0, 4);
		return co == OWNER_TOWN ? OWNER_NONE : co;
		
	} else {
		return (Owner)GB(_m[tile].m1, 0, 5);
	}
}

/**
 * Sets the owner of a tile
 *
 * This function sets the owner status of a tile. Note that you cannot
 * set a owner for tiles of type MP_HOUSE, MP_VOID and MP_INDUSTRY.
 *
 * @param tile The tile to change the owner status.
 * @param owner The new owner.
 * @pre IsValidTile(tile)
 * @pre The type of the tile must not be MP_HOUSE and MP_INDUSTRY
 */
static inline void SetTileOwner(TileIndex tile, Owner owner)
{
	assert(IsValidTile(tile));
	assert(!IsTileType(tile, MP_HOUSE));
	assert(!IsTileType(tile, MP_INDUSTRY));
	if ((IsTileType(tile, MP_STATION) || IsTileType(tile, MP_WATER) || IsTileType(tile, MP_OBJECT)) && owner == OWNER_TOWN) {
		SB(_m[tile].m1, 0, 4, OWNER_TOWN);
	} else {
		SB(_m[tile].m1, 0, 5, owner);
	}
}