Allow overriding town settings on a per-town basis

Add a setting for whether this is allowed for non-privileged
multiplayer clients

src/command.cpp

@@ -155,6 +155,7 @@ CommandProc CmdFoundTown;
 CommandProc CmdRenameTown;
 CommandProc CmdRenameTownNonAdmin;
 CommandProc CmdDoTownAction;
+CommandProc CmdOverrideTownSetting;
 CommandProc CmdTownGrowthRate;
 CommandProc CmdTownRating;
 CommandProc CmdTownCargoGoal;
@@ -401,6 +402,7 @@ static const Command _command_proc_table[] = {
 	DEF_CMD(CmdRenameTown,                CMD_DEITY | CMD_SERVER, CMDT_OTHER_MANAGEMENT      ), // CMD_RENAME_TOWN
 	DEF_CMD(CmdRenameTownNonAdmin,                             0, CMDT_OTHER_MANAGEMENT      ), // CMD_RENAME_TOWN_NON_ADMIN
 	DEF_CMD(CmdDoTownAction,                                   0, CMDT_LANDSCAPE_CONSTRUCTION), // CMD_DO_TOWN_ACTION
+	DEF_CMD(CmdOverrideTownSetting,                            0, CMDT_OTHER_MANAGEMENT      ), // CMD_TOWN_SETTING_OVERRIDE
 	DEF_CMD(CmdTownCargoGoal,            CMD_LOG_AUX | CMD_DEITY, CMDT_OTHER_MANAGEMENT      ), // CMD_TOWN_CARGO_GOAL
 	DEF_CMD(CmdTownGrowthRate,           CMD_LOG_AUX | CMD_DEITY, CMDT_OTHER_MANAGEMENT      ), // CMD_TOWN_GROWTH_RATE
 	DEF_CMD(CmdTownRating,               CMD_LOG_AUX | CMD_DEITY, CMDT_OTHER_MANAGEMENT      ), // CMD_TOWN_RATING

src/command_type.h

@@ -347,6 +347,7 @@ enum Commands {
 	CMD_RENAME_TOWN,                  ///< rename a town
 	CMD_RENAME_TOWN_NON_ADMIN,        ///< rename a town, non-admin command
 	CMD_DO_TOWN_ACTION,               ///< do a action from the town detail window (like advertises or bribe)
+	CMD_TOWN_SETTING_OVERRIDE,        ///< override a town setting
 	CMD_TOWN_CARGO_GOAL,              ///< set the goal of a cargo for a town
 	CMD_TOWN_GROWTH_RATE,             ///< set the town growth rate
 	CMD_TOWN_RATING,                  ///< set rating of a company in a town

src/lang/english.txt

@@ -1332,6 +1332,8 @@ STR_CONFIG_SETTING_MONEY_CHEAT_MULTIPLAYER                      :Allow multiplay
 STR_CONFIG_SETTING_MONEY_CHEAT_MULTIPLAYER_HELPTEXT             :If enabled, non-admin multiplayer clients can use the money cheat. The money cheat is always available in single-player mode, and to the multiplayer server admin.
 STR_CONFIG_SETTING_RENAME_TOWNS_MULTIPLAYER                     :Allow multiplayer clients to rename towns: {STRING2}
 STR_CONFIG_SETTING_RENAME_TOWNS_MULTIPLAYER_HELPTEXT            :If enabled, non-admin multiplayer clients which are not spectating can rename towns. Renaming towns is always available in single-player mode, and to the multiplayer server admin.
+STR_CONFIG_SETTING_OVERRIDE_TOWN_SETTINGS_MULTIPLAYER           :Allow multiplayer clients to override town settings: {STRING2}
+STR_CONFIG_SETTING_OVERRIDE_TOWN_SETTINGS_MULTIPLAYER_HELPTEXT  :If enabled, non-admin multiplayer clients which are not spectating can override town settings, on a per-town basis. Overriding individual town settings is always available in single-player mode, and to the multiplayer server admin.
 
 STR_CONFIG_SETTING_MAP_HEIGHT_LIMIT                             :Map height limit: {STRING2}
 STR_CONFIG_SETTING_MAP_HEIGHT_LIMIT_HELPTEXT                    :Set the maximum height of the map terrain. With "(auto)" a good value will be picked after terrain generation
@@ -4478,6 +4480,17 @@ STR_LOCAL_AUTHORITY_ACTION_TOOLTIP_NEW_BUILDINGS                :{YELLOW}Fund th
 STR_LOCAL_AUTHORITY_ACTION_TOOLTIP_EXCLUSIVE_TRANSPORT          :{YELLOW}Buy 1 year's exclusive transport rights in town.{}Town authority will not allow passengers and cargo to use your competitors' stations.{}Cost: {CURRENCY_LONG}
 STR_LOCAL_AUTHORITY_ACTION_TOOLTIP_BRIBE                        :{YELLOW}Bribe the local authority to increase your rating, at the risk of a severe penalty if caught.{}Cost: {CURRENCY_LONG}
 
+###length 4
+STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_ALLOW_ROADS                :Allowed to build roads
+STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_ALLOW_LEVEL_CROSSINGS      :Allowed to level crossings
+STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_TUNNELS                    :Allowed to build tunnels
+STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_MAX_ROAD_SLOPE             :Limit building continuous inclined roads
+
+STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_DEFAULT                    :Default ({STRING1})
+STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_STR                        :{STRING}: {PUSH_COLOUR}{YELLOW}{STRING2}{POP_COLOUR}
+STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_TEXT                       :{YELLOW}Override the following setting for this individual town:{}{STRING}{}{STRING}
+STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_TOOLTIP                    :{BLACK}Change setting override
+
 # Goal window
 STR_GOALS_CAPTION                                               :{WHITE}{COMPANY} Goals
 STR_GOALS_SPECTATOR_CAPTION                                     :{WHITE}Global Goals

src/saveload/extended_ver_sl.cpp

@@ -175,6 +175,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_INDUSTRY_ANIM_MASK,     XSCF_IGNORABLE_ALL,       1,   1, "industry_anim_mask",        nullptr, nullptr, nullptr        },
 	{ XSLFI_NEW_SIGNAL_STYLES,      XSCF_NULL,                2,   2, "new_signal_styles",         nullptr, nullptr, "XBST,NSID"    },
 	{ XSLFI_NO_TREE_COUNTER,        XSCF_IGNORABLE_ALL,       1,   1, "no_tree_counter",           nullptr, nullptr, nullptr        },
+	{ XSLFI_TOWN_SETTING_OVERRIDE,  XSCF_NULL,                1,   1, "town_setting_override",     nullptr, nullptr, nullptr        },
 	{ XSLFI_SCRIPT_INT64,           XSCF_NULL,                1,   1, "script_int64",              nullptr, nullptr, nullptr        },
 	{ XSLFI_U64_TICK_COUNTER,       XSCF_NULL,                1,   1, "u64_tick_counter",          nullptr, nullptr, nullptr        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker

src/saveload/extended_ver_sl.h

@@ -128,6 +128,7 @@ enum SlXvFeatureIndex {
 	XSLFI_INDUSTRY_ANIM_MASK,                     ///< Industry tile animation masking
 	XSLFI_NEW_SIGNAL_STYLES,                      ///< New signal styles
 	XSLFI_NO_TREE_COUNTER,                        ///< No tree counter
+	XSLFI_TOWN_SETTING_OVERRIDE,                  ///< Town setting overrides
 
 	XSLFI_SCRIPT_INT64,                           ///< See: SLV_SCRIPT_INT64
 	XSLFI_U64_TICK_COUNTER,                       ///< See: SLV_U64_TICK_COUNTER

src/saveload/town_sl.cpp

@@ -243,6 +243,11 @@ static const SaveLoad _town_desc[] = {
 	SLE_CONDNULL(4, SLV_166, SLV_EXTEND_CARGOTYPES),  ///< cargo_produced, no longer in use
 	SLE_CONDNULL(8, SLV_EXTEND_CARGOTYPES, SLV_REMOVE_TOWN_CARGO_CACHE),  ///< cargo_produced, no longer in use
 	SLE_CONDNULL(30, SLV_2, SLV_REMOVE_TOWN_CARGO_CACHE), ///< old reserved space
+
+	SLE_CONDVAR_X(Town, override_flags,      SLE_UINT8, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_TOWN_SETTING_OVERRIDE)),
+	SLE_CONDVAR_X(Town, override_values,     SLE_UINT8, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_TOWN_SETTING_OVERRIDE)),
+	SLE_CONDVAR_X(Town, build_tunnels,       SLE_UINT8, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_TOWN_SETTING_OVERRIDE)),
+	SLE_CONDVAR_X(Town, max_road_slope,      SLE_UINT8, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_TOWN_SETTING_OVERRIDE)),
 };
 
 static const SaveLoad _town_supplied_desc[] = {

src/settings.cpp

@@ -1465,6 +1465,11 @@ static void DifficultyRenameTownsMultiplayerChange(int32 new_value)
 	SetWindowClassesDirty(WC_TOWN_VIEW);
 }
 
+static void DifficultyOverrideTownSettingsMultiplayerChange(int32 new_value)
+{
+	SetWindowClassesDirty(WC_TOWN_AUTHORITY);
+}
+
 static void MaxNoAIsChange(int32 new_value)
 {
 	if (GetGameSettings().difficulty.max_no_competitors != 0 &&

src/settings_gui.cpp

@@ -2283,6 +2283,7 @@ static SettingsContainer &GetSettingsTree()
 			ai->Add(new SettingEntry("economy.min_years_for_shares"));
 			ai->Add(new SettingEntry("difficulty.money_cheat_in_multiplayer"));
 			ai->Add(new SettingEntry("difficulty.rename_towns_in_multiplayer"));
+			ai->Add(new SettingEntry("difficulty.override_town_settings_in_multiplayer"));
 		}
 
 		SettingsPage *scenario = main->Add(new SettingsPage(STR_CONFIG_SETTING_SCENARIO_EDITOR));

src/settings_type.h

@@ -97,6 +97,7 @@ struct DifficultySettings {
 	byte   town_council_tolerance;           ///< minimum required town ratings to be allowed to demolish stuff
 	bool   money_cheat_in_multiplayer;       ///< is the money cheat permitted for non-admin multiplayer clients
 	bool   rename_towns_in_multiplayer;      ///< is renaming towns permitted for non-admin multiplayer clients
+	bool   override_town_settings_in_multiplayer; ///< is overriding town settings permitted for non-admin multiplayer clients
 };
 
 /** Settings relating to viewport/smallmap scrolling. */

src/table/settings/settings.ini

@@ -27,6 +27,7 @@ static bool TownCouncilToleranceAdjust(int32 &new_value);
 static void DifficultyNoiseChange(int32 new_value);
 static void DifficultyMoneyCheatMultiplayerChange(int32 new_value);
 static void DifficultyRenameTownsMultiplayerChange(int32 new_value);
+static void DifficultyOverrideTownSettingsMultiplayerChange(int32 new_value);
 static void MaxNoAIsChange(int32 new_value);
 static bool CheckRoadSide(int32 &new_value);
 static void RoadSideChanged(int32 new_value);
@@ -476,6 +477,15 @@ post_cb  = DifficultyRenameTownsMultiplayerChange
 cat      = SC_EXPERT
 patxname = ""cheat.difficulty.rename_towns_in_multiplayer""
 
+[SDT_BOOL]
+var      = difficulty.override_town_settings_in_multiplayer
+def      = false
+str      = STR_CONFIG_SETTING_OVERRIDE_TOWN_SETTINGS_MULTIPLAYER
+strhelp  = STR_CONFIG_SETTING_OVERRIDE_TOWN_SETTINGS_MULTIPLAYER_HELPTEXT
+post_cb  = DifficultyOverrideTownSettingsMultiplayerChange
+cat      = SC_EXPERT
+patxname = ""cheat.difficulty.override_town_settings_in_multiplayer""
+
 [SDTG_VAR]
 name     = ""diff_level""
 var      = _old_diff_level

src/town.h

@@ -59,6 +59,14 @@ struct TownCache {
 	BuildingCounts<uint16> building_counts;   ///< The number of each type of building in the town
 };
 
+/** Town setting override flags */
+enum TownSettingOverrideFlags {
+	TSOF_OVERRIDE_BUILD_ROADS               = 0,
+	TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS     = 1,
+	TSOF_OVERRIDE_BUILD_TUNNELS             = 2,
+	TSOF_OVERRIDE_BUILD_INCLINED_ROADS      = 3,
+};
+
 /** Town data structure. */
 struct Town : TownPool::PoolItem<&_town_pool> {
 	TileIndex xy;                  ///< town center tile
@@ -73,6 +81,12 @@ struct Town : TownPool::PoolItem<&_town_pool> {
 	mutable std::string cached_name; ///< NOSAVE: Cache of the resolved name of the town, if not using a custom town name
 
 	byte flags;                    ///< See #TownFlags.
+
+	byte override_flags;           ///< Bitmask of enabled flag overrides. See #TownSettingOverrideFlags.
+	byte override_values;          ///< Bitmask of flag override values. See #TownSettingOverrideFlags.
+	TownTunnelMode build_tunnels;  ///< If/when towns are allowed to build road tunnels (if TSOF_OVERRIDE_BUILD_TUNNELS set in override_flags)
+	uint8 max_road_slope;          ///< Maximum number of consecutive sloped road tiles which towns are allowed to build (if TSOF_OVERRIDE_BUILD_INCLINED_ROADS set in override_flags)
+
 	uint16 church_count;           ///< Number of church buildings in the town.
 	uint16 stadium_count;          ///< Number of stadium buildings in the town.
 
@@ -173,6 +187,26 @@ struct Town : TownPool::PoolItem<&_town_pool> {
 		return this->cached_name.c_str();
 	}
 
+	inline bool GetAllowBuildRoads() const
+	{
+		return HasBit(this->override_flags, TSOF_OVERRIDE_BUILD_ROADS) ? HasBit(this->override_values, TSOF_OVERRIDE_BUILD_ROADS) : _settings_game.economy.allow_town_roads;
+	}
+
+	inline bool GetAllowBuildLevelCrossings() const
+	{
+		return HasBit(this->override_flags, TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS) ? HasBit(this->override_values, TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS) : _settings_game.economy.allow_town_level_crossings;
+	}
+
+	inline TownTunnelMode GetBuildTunnelMode() const
+	{
+		return HasBit(this->override_flags, TSOF_OVERRIDE_BUILD_TUNNELS) ? this->build_tunnels : _settings_game.economy.town_build_tunnels;
+	}
+
+	inline uint8 GetBuildMaxRoadSlope() const
+	{
+		return HasBit(this->override_flags, TSOF_OVERRIDE_BUILD_INCLINED_ROADS) ? this->max_road_slope : _settings_game.economy.town_max_road_slope;
+	}
+
 	static inline Town *GetByTile(TileIndex tile)
 	{
 		return Town::Get(GetTownIndex(tile));

src/town_cmd.cpp

@@ -67,7 +67,7 @@ static Rect _record_house_rect;
 TownPool _town_pool("Town");
 INSTANTIATE_POOL_METHODS(Town)
 
-static bool CanFollowRoad(TileIndex tile, DiagDirection dir);
+static bool CanFollowRoad(const Town *t, TileIndex tile, DiagDirection dir);
 
 TownKdtree _town_kdtree(&Kdtree_TownXYFunc);
 
@@ -1311,7 +1311,7 @@ static bool CanRoadContinueIntoNextTile(const Town *t, const TileIndex tile, con
 
 	/* If the next tile is a railroad track, check if towns are allowed to build level crossings.
 	 * If level crossing are not allowed, reject the construction. Else allow DoCommand to determine if the rail track is buildable. */
-	if (IsTileType(next_tile, MP_RAILWAY) && !_settings_game.economy.allow_town_level_crossings) return false;
+	if (IsTileType(next_tile, MP_RAILWAY) && !t->GetAllowBuildLevelCrossings()) return false;
 
 	/* If a road tile can be built, the construction is allowed. */
 	return DoCommand(next_tile, rcmd | (rt << 4), t->index, DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD).Succeeded();
@@ -1452,7 +1452,8 @@ static bool GrowTownWithTunnel(const Town *t, const TileIndex tile, const DiagDi
 {
 	assert(tunnel_dir < DIAGDIR_END);
 
-	if (_settings_game.economy.town_build_tunnels == TTM_FORBIDDEN) return false;
+	const TownTunnelMode tunnel_mode = t->GetBuildTunnelMode();
+	if (tunnel_mode == TTM_FORBIDDEN) return false;
 
 	Slope slope = GetTileSlope(tile);
 
@@ -1467,7 +1468,7 @@ static bool GrowTownWithTunnel(const Town *t, const TileIndex tile, const DiagDi
 
 	/* There are two conditions for building tunnels: Under a mountain and under an obstruction. */
 	if (CanRoadContinueIntoNextTile(t, tile, tunnel_dir)) {
-		if (_settings_game.economy.town_build_tunnels != TTM_ALLOWED) return false;
+		if (tunnel_mode != TTM_ALLOWED) return false;
 
 		/* Only tunnel under a mountain if the slope is continuous for at least 4 tiles. We want tunneling to be a last resort for large hills. */
 		TileIndex slope_tile = tile;
@@ -1571,8 +1572,8 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 		 * to say that this is the last iteration. */
 		_grow_town_result = GROWTH_SEARCH_STOPPED;
 
-		if (!_settings_game.economy.allow_town_roads && !_generating_world) return;
-		if (!_settings_game.economy.allow_town_level_crossings && IsTileType(tile, MP_RAILWAY)) return;
+		if (!t1->GetAllowBuildRoads() && !_generating_world) return;
+		if (!t1->GetAllowBuildLevelCrossings() && IsTileType(tile, MP_RAILWAY)) return;
 		if (!MayTownModifyRoad(tile)) return;
 
 		/* Remove hills etc */
@@ -1618,7 +1619,8 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 				break;
 		}
 
-		if (_settings_game.economy.town_max_road_slope > 0 && ((rcmd == ROAD_X) || (rcmd == ROAD_Y))) {
+		const uint8 max_road_slope = t1->GetBuildMaxRoadSlope();
+		if (max_road_slope > 0 && ((rcmd == ROAD_X) || (rcmd == ROAD_Y))) {
 			/* Limit consecutive sloped road tiles */
 
 			auto get_road_slope = [rcmd](TileIndex t) -> Slope {
@@ -1633,7 +1635,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 				const int delta = TileOffsByDiagDir(ReverseDiagDir(target_dir));
 				bool ok = false;
 				TileIndex t = tile;
-				for (uint i = 0; i < _settings_game.economy.town_max_road_slope; i++) {
+				for (uint i = 0; i < max_road_slope; i++) {
 					t += delta;
 					if (!IsValidTile(t) || !IsNormalRoadTile(t) || GetRoadBits(t, RTT_ROAD) != rcmd || get_road_slope(t) != slope) {
 						ok = true;
@@ -1653,7 +1655,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 		 * the fitting RoadBits */
 		_grow_town_result = GROWTH_SEARCH_STOPPED;
 
-		if (!_settings_game.economy.allow_town_roads && !_generating_world) return;
+		if (!t1->GetAllowBuildRoads() && !_generating_world) return;
 
 		switch (t1->layout) {
 			default: NOT_REACHED();
@@ -1691,7 +1693,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 						target_bits = DiagDirToRoadBits(target_dir);
 					} while (!(cur_rb & target_bits));
 					cur_rb &= ~target_bits;
-				} while (!(target_dir == GetTunnelBridgeDirection(tile) || CanFollowRoad(tile, target_dir)));
+				} while (!(target_dir == GetTunnelBridgeDirection(tile) || CanFollowRoad(t1, tile, target_dir)));
 				if (target_dir == GetTunnelBridgeDirection(tile)) {
 					/* cross the bridge */
 					*tile_ptr = GetOtherTunnelBridgeEnd(tile);
@@ -1746,7 +1748,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 
 		if (!IsValidTile(house_tile)) return;
 
-		if (target_dir != DIAGDIR_END && (_settings_game.economy.allow_town_roads || _generating_world)) {
+		if (target_dir != DIAGDIR_END && (t1->GetAllowBuildRoads() || _generating_world)) {
 			switch (t1->layout) {
 				default: NOT_REACHED();
 
@@ -1811,18 +1813,19 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 /**
  * Checks whether a road can be followed or is a dead end, that can not be extended to the next tile.
  * This only checks trivial but often cases.
+ * @param t Town doing the following
  * @param tile Start tile for road.
  * @param dir Direction for road to follow or build.
  * @return true If road is or can be connected in the specified direction.
  */
-static bool CanFollowRoad(TileIndex tile, DiagDirection dir)
+static bool CanFollowRoad(const Town *t, TileIndex tile, DiagDirection dir)
 {
 	TileIndex target_tile = tile + TileOffsByDiagDir(dir);
 	if (!IsValidTile(target_tile)) return false;
 	if (HasTileWaterGround(target_tile)) return false;
 
 	RoadBits target_rb = GetTownRoadBits(target_tile);
-	if (_settings_game.economy.allow_town_roads || _generating_world) {
+	if (t->GetAllowBuildRoads() || _generating_world) {
 		/* Check whether a road connection exists or can be build. */
 		switch (GetTileType(target_tile)) {
 			case MP_ROAD:
@@ -1922,7 +1925,7 @@ static bool GrowTownAtRoad(Town *t, TileIndex tile)
 					target_bits = DiagDirToRoadBits(target_dir);
 				} while (!(cur_rb & target_bits));
 				cur_rb &= ~target_bits;
-			} while (!CanFollowRoad(tile, target_dir));
+			} while (!CanFollowRoad(t, tile, target_dir));
 		}
 		tile = TileAddByDiagDir(tile, target_dir);
 
@@ -2001,7 +2004,7 @@ static bool GrowTown(Town *t)
 
 	/* No road available, try to build a random road block by
 	 * clearing some land and then building a road there. */
-	if (_settings_game.economy.allow_town_roads || _generating_world) {
+	if (t->GetAllowBuildRoads() || _generating_world) {
 		tile = t->xy;
 		for (ptr = _town_coord_mod; ptr != endof(_town_coord_mod); ++ptr) {
 			/* Only work with plain land that not already has a house */
@@ -2789,7 +2792,7 @@ static inline CommandCost IsAnotherHouseTypeAllowedInTown(Town *t, HouseID house
 static inline bool TownLayoutAllowsHouseHere(Town *t, const TileArea &ta)
 {
 	/* Allow towns everywhere when we don't build roads */
-	if (!_settings_game.economy.allow_town_roads && !_generating_world) return true;
+	if (!t->GetAllowBuildRoads() && !_generating_world) return true;
 
 	TileIndexDiffC grid_pos = TileIndexToTileIndexDiffC(t->xy, ta.tile);
 
@@ -3792,6 +3795,67 @@ CommandCost CmdDoTownAction(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 	return cost;
 }
 
+/**
+ * Override a town setting
+ * @param tile unused
+ * @param flags type of operation
+ * @param p1 town to do the action at
+ * @param p2 various bitstuffed elements
+ *  - p2 = (bit 0  -  7) - what setting to change
+ *  - p2 = (bit 8  - 15) - the data to modify
+ *  - p2 = (bit 16)      - whether to override the value, or use the default
+ * @param text unused
+ * @return the cost of this operation or an error
+ */
+CommandCost CmdOverrideTownSetting(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+{
+	if (_networking && !_settings_game.difficulty.override_town_settings_in_multiplayer) return CMD_ERROR;
+
+	Town *t = Town::GetIfValid(p1);
+	if (t == nullptr) return CMD_ERROR;
+
+	const uint8 setting = GB(p2, 0, 8);
+	const bool is_override = HasBit(p2, 16);
+	const uint8 value = GB(p2, 8, 8);
+	switch (setting) {
+		case TSOF_OVERRIDE_BUILD_ROADS:
+		case TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS:
+			if (is_override && value != 0 && value != 1) return CMD_ERROR;
+			break;
+		case TSOF_OVERRIDE_BUILD_TUNNELS:
+			if (is_override && value >= TTM_END) return CMD_ERROR;
+			break;
+		case TSOF_OVERRIDE_BUILD_INCLINED_ROADS:
+			if (is_override && value > 8) return CMD_ERROR;
+			break;
+		default:
+			return CMD_ERROR;
+	}
+
+	if (flags & DC_EXEC) {
+		SB(t->override_flags, setting, 1, is_override ? 1 : 0);
+		if (is_override) {
+			switch (setting) {
+				case TSOF_OVERRIDE_BUILD_ROADS:
+				case TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS:
+					SB(t->override_values, setting, 1, value & 1);
+					break;
+				case TSOF_OVERRIDE_BUILD_TUNNELS:
+					t->build_tunnels = (TownTunnelMode)value;
+					break;
+				case TSOF_OVERRIDE_BUILD_INCLINED_ROADS:
+					t->max_road_slope = value;
+					break;
+				default:
+					NOT_REACHED();
+			}
+		}
+		SetWindowDirty(WC_TOWN_AUTHORITY, p1);
+	}
+
+	return CommandCost();
+}
+
 template <typename Func>
 static void ForAllStationsNearTown(Town *t, Func func)
 {

src/town_gui.cpp

@@ -68,7 +68,10 @@ static const NWidgetPart _nested_town_authority_widgets[] = {
 	EndContainer(),
 	NWidget(WWT_PANEL, COLOUR_BROWN, WID_TA_ACTION_INFO), SetMinimalSize(317, 52), SetResize(1, 0), EndContainer(),
 	NWidget(NWID_HORIZONTAL),
-		NWidget(WWT_PUSHTXTBTN, COLOUR_BROWN, WID_TA_EXECUTE),  SetMinimalSize(317, 12), SetResize(1, 0), SetFill(1, 0), SetDataTip(STR_LOCAL_AUTHORITY_DO_IT_BUTTON, STR_LOCAL_AUTHORITY_DO_IT_TOOLTIP),
+		NWidget(NWID_SELECTION, INVALID_COLOUR, WID_TA_BTN_SEL),
+			NWidget(WWT_PUSHTXTBTN, COLOUR_BROWN, WID_TA_EXECUTE),  SetMinimalSize(317, 12), SetResize(1, 0), SetFill(1, 0), SetDataTip(STR_LOCAL_AUTHORITY_DO_IT_BUTTON, STR_LOCAL_AUTHORITY_DO_IT_TOOLTIP),
+			NWidget(WWT_DROPDOWN, COLOUR_BROWN, WID_TA_SETTING),  SetMinimalSize(317, 12), SetResize(1, 0), SetFill(1, 0), SetDataTip(STR_BLACK_STRING1, STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_TOOLTIP),
+		EndContainer(),
 		NWidget(WWT_RESIZEBOX, COLOUR_BROWN),
 	EndContainer()
 };
@@ -101,6 +104,14 @@ private:
 		return -1;
 	}
 
+	static bool ChangeSettingsDisabled()
+	{
+		return _networking && !(_network_server || _network_settings_access) &&
+				!(_local_company != COMPANY_SPECTATOR && _settings_game.difficulty.override_town_settings_in_multiplayer);
+	}
+
+	static const uint SETTING_OVERRIDE_COUNT = 4;
+
 public:
 	TownAuthorityWindow(WindowDesc *desc, WindowNumber window_number) : Window(desc), sel_index(-1), displayed_actions_on_previous_painting(0)
 	{
@@ -114,17 +125,20 @@ public:
 	{
 		int numact;
 		uint buttons = GetMaskOfTownActions(&numact, _local_company, this->town);
+		numact += SETTING_OVERRIDE_COUNT;
 		if (buttons != displayed_actions_on_previous_painting) this->SetDirty();
 		displayed_actions_on_previous_painting = buttons;
 
 		this->vscroll->SetCount(numact + 1);
 
-		if (this->sel_index != -1 && !HasBit(buttons, this->sel_index)) {
+		if (this->sel_index != -1 && this->sel_index < 0x100 && !HasBit(buttons, this->sel_index)) {
 			this->sel_index = -1;
 		}
 
 		this->SetWidgetLoweredState(WID_TA_ZONE_BUTTON, this->town->show_zone);
-		this->SetWidgetDisabledState(WID_TA_EXECUTE, this->sel_index == -1);
+		this->SetWidgetDisabledState(WID_TA_EXECUTE, this->sel_index == -1 || this->sel_index >= 0x100);
+		this->SetWidgetDisabledState(WID_TA_SETTING, ChangeSettingsDisabled());
+		this->GetWidget<NWidgetStacked>(WID_TA_BTN_SEL)->SetDisplayedPlane(this->sel_index >= 0x100 ? 1 : 0);
 
 		this->DrawWidgets();
 		if (!this->IsShaded()) this->DrawRatings();
@@ -193,7 +207,31 @@ public:
 
 	void SetStringParameters(int widget) const override
 	{
-		if (widget == WID_TA_CAPTION) SetDParam(0, this->window_number);
+		if (widget == WID_TA_CAPTION) {
+			SetDParam(0, this->window_number);
+		} else if (widget == WID_TA_SETTING) {
+			SetDParam(0, STR_EMPTY);
+			if (this->sel_index >= 0x100 && this->sel_index < (int)(0x100 + SETTING_OVERRIDE_COUNT)) {
+				if (!HasBit(this->town->override_flags, this->sel_index - 0x100)) {
+					SetDParam(0, STR_COLOUR_DEFAULT);
+				} else {
+					int idx = this->sel_index - 0x100;
+					switch (idx) {
+						case TSOF_OVERRIDE_BUILD_ROADS:
+						case TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS:
+							SetDParam(0, HasBit(this->town->override_values, idx) ? STR_CONFIG_SETTING_ON : STR_CONFIG_SETTING_OFF);
+							break;
+						case TSOF_OVERRIDE_BUILD_TUNNELS:
+							SetDParam(0, STR_CONFIG_SETTING_TOWN_TUNNELS_FORBIDDEN + this->town->build_tunnels);
+							break;
+						case TSOF_OVERRIDE_BUILD_INCLINED_ROADS:
+							SetDParam(0, STR_CONFIG_SETTING_TOWN_MAX_ROAD_SLOPE_VALUE + ((this->town->max_road_slope == 0) ? 1 : 0));
+							SetDParam(1, this->town->max_road_slope);
+							break;
+					}
+				}
+			}
+		}
 	}
 
 	void DrawWidget(const Rect &r, int widget) const override
@@ -201,14 +239,36 @@ public:
 		switch (widget) {
 			case WID_TA_ACTION_INFO:
 				if (this->sel_index != -1) {
-					SetDParam(0, _price[PR_TOWN_ACTION] * _town_action_costs[this->sel_index] >> 8);
-					DrawStringMultiLine(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, r.top + WD_FRAMERECT_TOP, r.bottom - WD_FRAMERECT_BOTTOM,
-								STR_LOCAL_AUTHORITY_ACTION_TOOLTIP_SMALL_ADVERTISING + this->sel_index);
+					StringID text = STR_NULL;
+					if (this->sel_index >= 0x100) {
+						SetDParam(1, STR_EMPTY);
+						switch (this->sel_index - 0x100) {
+							case TSOF_OVERRIDE_BUILD_ROADS:
+								SetDParam(1, STR_CONFIG_SETTING_ALLOW_TOWN_ROADS_HELPTEXT);
+								break;
+							case TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS:
+								SetDParam(1, STR_CONFIG_SETTING_ALLOW_TOWN_LEVEL_CROSSINGS_HELPTEXT);
+								break;
+							case TSOF_OVERRIDE_BUILD_TUNNELS:
+								SetDParam(1, STR_CONFIG_SETTING_TOWN_TUNNELS_HELPTEXT);
+								break;
+							case TSOF_OVERRIDE_BUILD_INCLINED_ROADS:
+								SetDParam(1, STR_CONFIG_SETTING_TOWN_MAX_ROAD_SLOPE_HELPTEXT);
+								break;
+						}
+						text = STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_TEXT;
+						SetDParam(0, STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_ALLOW_ROADS + this->sel_index - 0x100);
+					} else {
+						text = STR_LOCAL_AUTHORITY_ACTION_TOOLTIP_SMALL_ADVERTISING + this->sel_index;
+						SetDParam(0, _price[PR_TOWN_ACTION] * _town_action_costs[this->sel_index] >> 8);
+					}
+					DrawStringMultiLine(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, r.top + WD_FRAMERECT_TOP, r.bottom - WD_FRAMERECT_BOTTOM, text);
 				}
 				break;
 			case WID_TA_COMMAND_LIST: {
 				int numact;
 				uint buttons = GetMaskOfTownActions(&numact, _local_company, this->town);
+				numact += SETTING_OVERRIDE_COUNT;
 				int y = r.top + WD_FRAMERECT_TOP;
 				int pos = this->vscroll->GetPosition();
 
@@ -218,14 +278,47 @@ public:
 				}
 
 				for (int i = 0; buttons; i++, buttons >>= 1) {
-					if (pos <= -5) break; ///< Draw only the 5 fitting lines
-
 					if ((buttons & 1) && --pos < 0) {
 						DrawString(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, y,
 								STR_LOCAL_AUTHORITY_ACTION_SMALL_ADVERTISING_CAMPAIGN + i, this->sel_index == i ? TC_WHITE : TC_ORANGE);
 						y += FONT_HEIGHT_NORMAL;
 					}
 				}
+				for (int i = 0; i < (int)SETTING_OVERRIDE_COUNT; i++) {
+					if (--pos < 0) {
+						const bool disabled = ChangeSettingsDisabled();
+						const bool selected = (this->sel_index == (0x100 + i));
+						const TextColour tc = disabled ? (TC_NO_SHADE | (selected ? TC_SILVER : TC_GREY)) : (selected ? TC_WHITE : TC_ORANGE);
+						const bool overriden = HasBit(this->town->override_flags, i);
+						SetDParam(0, STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_ALLOW_ROADS + i);
+						SetDParam(1, overriden ? STR_JUST_STRING1 : STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_DEFAULT);
+						switch (i) {
+							case TSOF_OVERRIDE_BUILD_ROADS:
+								SetDParam(2, this->town->GetAllowBuildRoads() ? STR_CONFIG_SETTING_ON : STR_CONFIG_SETTING_OFF);
+								break;
+
+							case TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS:
+								SetDParam(2, this->town->GetAllowBuildLevelCrossings() ? STR_CONFIG_SETTING_ON : STR_CONFIG_SETTING_OFF);
+								break;
+
+							case TSOF_OVERRIDE_BUILD_TUNNELS: {
+								TownTunnelMode tunnel_mode = this->town->GetBuildTunnelMode();
+								SetDParam(2, STR_CONFIG_SETTING_TOWN_TUNNELS_FORBIDDEN + tunnel_mode);
+								break;
+							}
+
+							case TSOF_OVERRIDE_BUILD_INCLINED_ROADS: {
+								uint8 max_slope = this->town->GetBuildMaxRoadSlope();
+								SetDParam(2, STR_CONFIG_SETTING_TOWN_MAX_ROAD_SLOPE_VALUE + ((max_slope == 0) ? 1 : 0));
+								SetDParam(3, max_slope);
+								break;
+							}
+						}
+						DrawString(r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, y,
+								STR_LOCAL_AUTHORITY_SETTING_OVERRIDE_STR, tc);
+						y += FONT_HEIGHT_NORMAL;
+					}
+				}
 				break;
 			}
 		}
@@ -250,7 +343,7 @@ public:
 			}
 
 			case WID_TA_COMMAND_LIST:
-				size->height = WD_FRAMERECT_TOP + 5 * FONT_HEIGHT_NORMAL + WD_FRAMERECT_BOTTOM;
+				size->height = WD_FRAMERECT_TOP + (5 + SETTING_OVERRIDE_COUNT) * FONT_HEIGHT_NORMAL + WD_FRAMERECT_BOTTOM;
 				size->width = GetStringBoundingBox(STR_LOCAL_AUTHORITY_ACTIONS_TITLE).width;
 				for (uint i = 0; i < TACT_COUNT; i++ ) {
 					size->width = std::max(size->width, GetStringBoundingBox(STR_LOCAL_AUTHORITY_ACTION_SMALL_ADVERTISING_CAMPAIGN + i).width);
@@ -283,10 +376,16 @@ public:
 
 			case WID_TA_COMMAND_LIST: {
 				int y = this->GetRowFromWidget(pt.y, WID_TA_COMMAND_LIST, 1, FONT_HEIGHT_NORMAL);
-				if (!IsInsideMM(y, 0, 5)) return;
+				if (!IsInsideMM(y, 0, 5 + SETTING_OVERRIDE_COUNT)) return;
 
-				y = GetNthSetBit(GetMaskOfTownActions(nullptr, _local_company, this->town), y + this->vscroll->GetPosition() - 1);
-				if (y >= 0) {
+				const uint setting_override_offset = 32 - SETTING_OVERRIDE_COUNT;
+
+				y = GetNthSetBit(GetMaskOfTownActions(nullptr, _local_company, this->town) | (UINT32_MAX << setting_override_offset), y + this->vscroll->GetPosition() - 1);
+				if (y >= (int)setting_override_offset) {
+					this->sel_index = y + 0x100 - setting_override_offset;
+					this->SetDirty();
+					break;
+				} else if (y >= 0) {
 					this->sel_index = y;
 					this->SetDirty();
 				}
@@ -298,9 +397,71 @@ public:
 			case WID_TA_EXECUTE:
 				DoCommandP(this->town->xy, this->window_number, this->sel_index, CMD_DO_TOWN_ACTION | CMD_MSG(STR_ERROR_CAN_T_DO_THIS));
 				break;
+
+			case WID_TA_SETTING: {
+				uint8 idx = this->sel_index - 0x100;
+				switch (idx) {
+					case TSOF_OVERRIDE_BUILD_ROADS:
+					case TSOF_OVERRIDE_BUILD_LEVEL_CROSSINGS: {
+						int value = HasBit(this->town->override_flags, idx) ? (HasBit(this->town->override_values, idx) ? 2 : 1) : 0;
+						const StringID names[] = {
+							STR_COLOUR_DEFAULT,
+							STR_CONFIG_SETTING_OFF,
+							STR_CONFIG_SETTING_ON,
+							INVALID_STRING_ID
+						};
+						ShowDropDownMenu(this, names, value, WID_TA_SETTING, 0, 0);
+						break;
+					}
+					case TSOF_OVERRIDE_BUILD_TUNNELS: {
+						const StringID names[] = {
+							STR_COLOUR_DEFAULT,
+							STR_CONFIG_SETTING_TOWN_TUNNELS_FORBIDDEN,
+							STR_CONFIG_SETTING_TOWN_TUNNELS_ALLOWED_OBSTRUCTION,
+							STR_CONFIG_SETTING_TOWN_TUNNELS_ALLOWED,
+							INVALID_STRING_ID
+						};
+						ShowDropDownMenu(this, names, HasBit(this->town->override_flags, idx) ? this->town->build_tunnels + 1 : 0, WID_TA_SETTING, 0, 0);
+						break;
+					}
+					case TSOF_OVERRIDE_BUILD_INCLINED_ROADS:
+						DropDownList dlist;
+						dlist.emplace_back(new DropDownListStringItem(STR_COLOUR_DEFAULT, 0, false));
+						dlist.emplace_back(new DropDownListStringItem(STR_CONFIG_SETTING_TOWN_MAX_ROAD_SLOPE_ZERO, 1, false));
+						for (int i = 1; i <= 8; i++) {
+							DropDownListParamStringItem *item = new DropDownListParamStringItem(STR_CONFIG_SETTING_TOWN_MAX_ROAD_SLOPE_VALUE, i + 1, false);
+							item->SetParam(0, i);
+							dlist.emplace_back(item);
+						}
+						ShowDropDownList(this, std::move(dlist), HasBit(this->town->override_flags, idx) ? this->town->max_road_slope + 1 : 0, WID_TA_SETTING);
+						break;
+				}
+				break;
+			}
 		}
 	}
 
+
+	virtual void OnDropdownSelect(int widget, int index) override
+	{
+		switch (widget) {
+			case WID_TA_SETTING: {
+				if (index < 0) break;
+				uint32 p2 = this->sel_index - 0x100;
+				if (index > 0) {
+					SetBit(p2, 16);
+					p2 |= (index - 1) << 8;
+				}
+				DoCommandP(this->town->xy, this->window_number, p2, CMD_TOWN_SETTING_OVERRIDE | CMD_MSG(STR_ERROR_CAN_T_DO_THIS));
+				break;
+			}
+
+			default: NOT_REACHED();
+		}
+
+		this->SetDirty();
+	}
+
 	void OnHundredthTick() override
 	{
 		this->SetDirty();
@@ -477,7 +638,7 @@ public:
 				/* Warn the user if towns are not allowed to build roads, but do this only once per OpenTTD run. */
 				static bool _warn_town_no_roads = false;
 
-				if (!_settings_game.economy.allow_town_roads && !_warn_town_no_roads) {
+				if (!Town::Get(this->window_number)->GetAllowBuildRoads() && !_warn_town_no_roads) {
 					ShowErrorMessage(STR_ERROR_TOWN_EXPAND_WARN_NO_ROADS, INVALID_STRING_ID, WL_WARNING);
 					_warn_town_no_roads = true;
 				}

src/widgets/town_widget.h

@@ -29,6 +29,8 @@ enum TownAuthorityWidgets {
 	WID_TA_SCROLLBAR,    ///< Scrollbar of the list of commands.
 	WID_TA_ACTION_INFO,  ///< Additional information about the action.
 	WID_TA_EXECUTE,      ///< Do-it button.
+	WID_TA_SETTING,      ///< Setting drop-down.
+	WID_TA_BTN_SEL,      ///< Button selector.
 };
 
 /** Widgets of the #TownViewWindow class. */