Function CmdBuildObject

src/object_cmd.cpp:210–385

* Build an object object * @param flags type of operation * @param tile tile where the object will be located * @param type the object type to build * @param view the view for the object * @return the cost of this operation or an error */

 * @return the cost of this operation or an error
 */
CommandCost CmdBuildObject(DoCommandFlags flags, TileIndex tile, ObjectType type, uint8_t view)
{
	CommandCost cost(EXPENSES_CONSTRUCTION);

	if (type >= ObjectSpec::Count()) return CMD_ERROR;
	const ObjectSpec *spec = ObjectSpec::Get(type);
	if (_game_mode == GM_NORMAL && !spec->IsAvailable() && !_generating_world) return CMD_ERROR;
	if ((_game_mode == GM_EDITOR || _generating_world) && !spec->WasEverAvailable()) return CMD_ERROR;

	if (spec->flags.Test(ObjectFlag::OnlyInScenedit) && ((!_generating_world && _game_mode != GM_EDITOR) || _current_company != OWNER_NONE)) return CMD_ERROR;
	if (spec->flags.Test(ObjectFlag::OnlyInGame) && (_generating_world || _game_mode != GM_NORMAL || _current_company > MAX_COMPANIES)) return CMD_ERROR;
	if (view >= spec->views) return CMD_ERROR;

	if (!Object::CanAllocateItem()) return CommandCost(STR_ERROR_TOO_MANY_OBJECTS);
	if (Town::GetNumItems() == 0) return CommandCost(STR_ERROR_MUST_FOUND_TOWN_FIRST);

	int size_x = GB(spec->size, HasBit(view, 0) ? 4 : 0, 4);
	int size_y = GB(spec->size, HasBit(view, 0) ? 0 : 4, 4);
	TileArea ta(tile, size_x, size_y);
	for (TileIndex t : ta) {
		if (!IsValidTile(t)) return CommandCost(STR_ERROR_TOO_CLOSE_TO_EDGE_OF_MAP_SUB); // Might be off the map
	}

	if (type == OBJECT_OWNED_LAND) {
		/* Owned land is special as it can be placed on any slope. */
		cost.AddCost(Command<CMD_LANDSCAPE_CLEAR>::Do(flags, tile));
	} else {
		/* Check the surface to build on. At this time we can't actually execute the
		 * the CLEAR_TILE commands since the newgrf callback later on can check
		 * some information about the tiles. */
		bool allow_water = spec->flags.Any({ObjectFlag::BuiltOnWater, ObjectFlag::NotOnLand});
		bool allow_ground = !spec->flags.Test(ObjectFlag::NotOnLand);
		for (TileIndex t : ta) {
			if (HasTileWaterGround(t)) {
				if (!allow_water) return CommandCost(STR_ERROR_CAN_T_BUILD_ON_WATER);
				if (!IsWaterTile(t)) {
					/* Normal water tiles don't have to be cleared. For all other tile types clear
					 * the tile but leave the water. */
					cost.AddCost(Command<CMD_LANDSCAPE_CLEAR>::Do(DoCommandFlags{flags}.Reset({DoCommandFlag::NoWater, DoCommandFlag::Execute}), t));
				} else {
					/* Can't build on water owned by another company. */
					Owner o = GetTileOwner(t);
					if (o != OWNER_NONE && o != OWNER_WATER) cost.AddCost(CheckOwnership(o, t));

					/* If freeform edges are disabled, don't allow building on edge tiles. */
					if (!_settings_game.construction.freeform_edges && (!IsInsideMM(TileX(t), 1, Map::MaxX() - 1) || !IsInsideMM(TileY(t), 1, Map::MaxY() - 1))) {
						return CommandCost(STR_ERROR_TOO_CLOSE_TO_EDGE_OF_MAP);
					}

					/* However, the tile has to be clear of vehicles. */
					cost.AddCost(EnsureNoVehicleOnGround(t));
				}
			} else {
				if (!allow_ground) return CommandCost(STR_ERROR_MUST_BE_BUILT_ON_WATER);
				/* For non-water tiles, we'll have to clear it before building. */

				/* When relocating HQ, allow it to be relocated (partial) on itself. */
				if (!(type == OBJECT_HQ &&