Function IsStationBridgeAboveOk

src/station_cmd.cpp:887–902

* Test if a bridge can be built above a station. * @param tile Tile to test. * @param spec Custom station spec to test. * @param type Type of station. * @param layout Layout piece of road station to test. * @param bridge_height Height of bridge to test. * @param disallowed_msg Error message if bridge is disallowed. * @return Command result. */

 * @return Command result.
 */
static CommandCost IsStationBridgeAboveOk(TileIndex tile, std::span<const BridgeableTileInfo> bridgeable_info, StationType type, StationGfx layout, int bridge_height, StringID disallowed_msg = INVALID_STRING_ID)
{
	int height = layout < std::size(bridgeable_info) ? bridgeable_info[layout].height : 0;

	if (height == 0) {
		if (disallowed_msg != INVALID_STRING_ID) return CommandCost{disallowed_msg};
		/* Get normal error message associated with clearing the tile. */
		return Command<CMD_LANDSCAPE_CLEAR>::Do(DoCommandFlag::Auto, tile);
	}
	if (GetTileMaxZ(tile) + height > bridge_height) {
		int height_diff = (GetTileMaxZ(tile) + height - bridge_height) * TILE_HEIGHT_STEP;
		return CommandCostWithParam(GetBridgeTooLowMessageForStationType(type), height_diff);
	}

	return CommandCost{};
}

/**
 * Get bridgeable tile information for a station type.