14 files changed, 529 insertions, 458 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 801a92cb3..631eaf6de 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -338,6 +338,8 @@ add_files(
     settings_gui.cpp
     settings_gui.h
     settings_internal.h
+    settings_table.h
+    settings_table.cpp
     settings_type.h
     ship.h
     ship_cmd.cpp
diff --git a/src/settings.cpp b/src/settings.cpp
index 64ce47828..a2ab8ae33 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -22,62 +22,31 @@
  */
 
 #include "stdafx.h"
-#include <array>
 #include <charconv>
-#include <limits>
+#include "settings_table.h"
+#include "debug.h"
 #include "currency.h"
-#include "screenshot.h"
 #include "network/network.h"
 #include "network/network_func.h"
-#include "settings_internal.h"
 #include "command_func.h"
 #include "console_func.h"
-#include "pathfinder/pathfinder_type.h"
 #include "genworld.h"
-#include "train.h"
-#include "news_func.h"
 #include "window_func.h"
-#include "sound_func.h"
 #include "company_func.h"
 #include "rev.h"
-#if defined(WITH_FREETYPE) || defined(_WIN32) || defined(WITH_COCOA)
-#include "fontcache.h"
-#endif
-#include "textbuf_gui.h"
-#include "rail_gui.h"
-#include "elrail_func.h"
 #include "error.h"
-#include "town.h"
-#include "video/video_driver.hpp"
-#include "sound/sound_driver.hpp"
-#include "music/music_driver.hpp"
-#include "blitter/factory.hpp"
-#include "base_media_base.h"
 #include "gamelog.h"
 #include "settings_func.h"
 #include "ini_type.h"
 #include "ai/ai_config.hpp"
-#include "ai/ai.hpp"
 #include "game/game_config.hpp"
-#include "game/game.hpp"
-#include "ship.h"
-#include "smallmap_gui.h"
-#include "roadveh.h"
+#include "newgrf_config.h"
 #include "fios.h"
-#include "strings_func.h"
-#include "vehicle_func.h"
+#include "fileio_func.h"
 
 #include "saveload/compat/settings_sl_compat.h"
 
-#include "void_map.h"
-#include "station_base.h"
-
-#if defined(WITH_FREETYPE) || defined(_WIN32) || defined(WITH_COCOA)
-#define HAS_TRUETYPE_FONT
-#endif
-
 #include "table/strings.h"
-#include "table/settings.h"
 
 #include "safeguards.h"
 
@@ -92,8 +61,6 @@ std::string _secrets_file; ///< Secrets configuration file of OpenTTD.
 typedef std::list<ErrorMessageData> ErrorList;
 static ErrorList _settings_error_list; ///< Errors while loading minimal settings.
 
-typedef span<const SettingVariant> SettingTable;
-
 /**
  * List of all the generic setting tables.
  *
@@ -865,227 +832,6 @@ const StringSettingDesc *SettingDesc::AsStringSetting() const
 	return static_cast<const StringSettingDesc *>(this);
 }
 
-/* Begin - Callback Functions for the various settings. */
-
-/** Reposition the main toolbar as the setting changed. */
-static void v_PositionMainToolbar(int32 new_value)
-{
-	if (_game_mode != GM_MENU) PositionMainToolbar(nullptr);
-}
-
-/** Reposition the statusbar as the setting changed. */
-static void v_PositionStatusbar(int32 new_value)
-{
-	if (_game_mode != GM_MENU) {
-		PositionStatusbar(nullptr);
-		PositionNewsMessage(nullptr);
-		PositionNetworkChatWindow(nullptr);
-	}
-}
-
-/**
- * Redraw the smallmap after a colour scheme change.
- * @param p1 Callback parameter.
- */
-static void RedrawSmallmap(int32 new_value)
-{
-	BuildLandLegend();
-	BuildOwnerLegend();
-	SetWindowClassesDirty(WC_SMALLMAP);
-}
-
-static void StationSpreadChanged(int32 p1)
-{
-	InvalidateWindowData(WC_SELECT_STATION, 0);
-	InvalidateWindowData(WC_BUILD_STATION, 0);
-}
-
-static void CloseSignalGUI(int32 new_value)
-{
-	if (new_value == 0) {
-		CloseWindowByClass(WC_BUILD_SIGNAL);
-	}
-}
-
-static void UpdateConsists(int32 new_value)
-{
-	for (Train *t : Train::Iterate()) {
-		/* Update the consist of all trains so the maximum speed is set correctly. */
-		if (t->IsFrontEngine() || t->IsFreeWagon()) t->ConsistChanged(CCF_TRACK);
-	}
-	InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
-}
-
-/* Check service intervals of vehicles, newvalue is value of % or day based servicing */
-static void UpdateAllServiceInterval(int32 new_value)
-{
-	bool update_vehicles;
-	VehicleDefaultSettings *vds;
-	if (_game_mode == GM_MENU || !Company::IsValidID(_current_company)) {
-		vds = &_settings_client.company.vehicle;
-		update_vehicles = false;
-	} else {
-		vds = &Company::Get(_current_company)->settings.vehicle;
-		update_vehicles = true;
-	}
-
-	if (new_value != 0) {
-		vds->servint_trains   = 50;
-		vds->servint_roadveh  = 50;
-		vds->servint_aircraft = 50;
-		vds->servint_ships    = 50;
-	} else {
-		vds->servint_trains   = 150;
-		vds->servint_roadveh  = 150;
-		vds->servint_aircraft = 100;
-		vds->servint_ships    = 360;
-	}
-
-	if (update_vehicles) {
-		const Company *c = Company::Get(_current_company);
-		for (Vehicle *v : Vehicle::Iterate()) {
-			if (v->owner == _current_company && v->IsPrimaryVehicle() && !v->ServiceIntervalIsCustom()) {
-				v->SetServiceInterval(CompanyServiceInterval(c, v->type));
-				v->SetServiceIntervalIsPercent(new_value != 0);
-			}
-		}
-	}
-
-	SetWindowClassesDirty(WC_VEHICLE_DETAILS);
-}
-
-static bool CanUpdateServiceInterval(VehicleType type, int32 &new_value)
-{
-	VehicleDefaultSettings *vds;
-	if (_game_mode == GM_MENU || !Company::IsValidID(_current_company)) {
-		vds = &_settings_client.company.vehicle;
-	} else {
-		vds = &Company::Get(_current_company)->settings.vehicle;
-	}
-
-	/* Test if the interval is valid */
-	int32 interval = GetServiceIntervalClamped(new_value, vds->servint_ispercent);
-	return interval == new_value;
-}
-
-static void UpdateServiceInterval(VehicleType type, int32 new_value)
-{
-	if (_game_mode != GM_MENU && Company::IsValidID(_current_company)) {
-		for (Vehicle *v : Vehicle::Iterate()) {
-			if (v->owner == _current_company && v->type == type && v->IsPrimaryVehicle() && !v->ServiceIntervalIsCustom()) {
-				v->SetServiceInterval(new_value);
-			}
-		}
-	}
-
-	SetWindowClassesDirty(WC_VEHICLE_DETAILS);
-}
-
-static void TrainAccelerationModelChanged(int32 new_value)
-{
-	for (Train *t : Train::Iterate()) {
-		if (t->IsFrontEngine()) {
-			t->tcache.cached_max_curve_speed = t->GetCurveSpeedLimit();
-			t->UpdateAcceleration();
-		}
-	}
-
-	/* These windows show acceleration values only when realistic acceleration is on. They must be redrawn after a setting change. */
-	SetWindowClassesDirty(WC_ENGINE_PREVIEW);
-	InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
-	SetWindowClassesDirty(WC_VEHICLE_DETAILS);
-}
-
-/**
- * This function updates the train acceleration cache after a steepness change.
- * @param new_value Unused new value of setting.
- */
-static void TrainSlopeSteepnessChanged(int32 new_value)
-{
-	for (Train *t : Train::Iterate()) {
-		if (t->IsFrontEngine()) t->CargoChanged();
-	}
-}
-
-/**
- * This function updates realistic acceleration caches when the setting "Road vehicle acceleration model" is set.
- * @param new_value Unused new value of setting.
- */
-static void RoadVehAccelerationModelChanged(int32 new_value)
-{
-	if (_settings_game.vehicle.roadveh_acceleration_model != AM_ORIGINAL) {
-		for (RoadVehicle *rv : RoadVehicle::Iterate()) {
-			if (rv->IsFrontEngine()) {
-				rv->CargoChanged();
-			}
-		}
-	}
-
-	/* These windows show acceleration values only when realistic acceleration is on. They must be redrawn after a setting change. */
-	SetWindowClassesDirty(WC_ENGINE_PREVIEW);
-	InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
-	SetWindowClassesDirty(WC_VEHICLE_DETAILS);
-}
-
-/**
- * This function updates the road vehicle acceleration cache after a steepness change.
- * @param new_value Unused new value of setting.
- */
-static void RoadVehSlopeSteepnessChanged(int32 new_value)
-{
-	for (RoadVehicle *rv : RoadVehicle::Iterate()) {
-		if (rv->IsFrontEngine()) rv->CargoChanged();
-	}
-}
-
-static void TownFoundingChanged(int32 new_value)
-{
-	if (_game_mode != GM_EDITOR && _settings_game.economy.found_town == TF_FORBIDDEN) {
-		CloseWindowById(WC_FOUND_TOWN, 0);
-	} else {
-		InvalidateWindowData(WC_FOUND_TOWN, 0);
-	}
-}
-
-static void ZoomMinMaxChanged(int32 new_value)
-{
-	extern void ConstrainAllViewportsZoom();
-	ConstrainAllViewportsZoom();
-	GfxClearSpriteCache();
-	if (_settings_client.gui.zoom_min > _gui_zoom) {
-		/* Restrict GUI zoom if it is no longer available. */
-		_gui_zoom = _settings_client.gui.zoom_min;
-		UpdateCursorSize();
-		LoadStringWidthTable();
-	}
-}
-
-static void SpriteZoomMinChanged(int32 new_value)
-{
-	GfxClearSpriteCache();
-	/* Force all sprites to redraw at the new chosen zoom level */
-	MarkWholeScreenDirty();
-}
-
-/**
- * Update any possible saveload window and delete any newgrf dialogue as
- * its widget parts might change. Reinit all windows as it allows access to the
- * newgrf debug button.
- * @param new_value unused.
- */
-static void InvalidateNewGRFChangeWindows(int32 new_value)
-{
-	InvalidateWindowClassesData(WC_SAVELOAD);
-	CloseWindowByClass(WC_GAME_OPTIONS);
-	ReInitAllWindows(_gui_zoom_cfg);
-}
-
-static void InvalidateCompanyLiveryWindow(int32 new_value)
-{
-	InvalidateWindowClassesData(WC_COMPANY_COLOUR, -1);
-	ResetVehicleColourMap();
-}
-
 /** Checks if any settings are set to incorrect values, and sets them to correct values in that case. */
 static void ValidateSettings()
 {
@@ -1096,193 +842,6 @@ static void ValidateSettings()
 	}
 }
 
-static void DifficultyNoiseChange(int32 new_value)
-{
-	if (_game_mode == GM_NORMAL) {
-		UpdateAirportsNoise();
-		if (_settings_game.economy.station_noise_level) {
-			InvalidateWindowClassesData(WC_TOWN_VIEW, 0);
-		}
-	}
-}
-
-static void MaxNoAIsChange(int32 new_value)
-{
-	if (GetGameSettings().difficulty.max_no_competitors != 0 &&
-			AI::GetInfoList()->size() == 0 &&
-			(!_networking || _network_server)) {
-		ShowErrorMessage(STR_WARNING_NO_SUITABLE_AI, INVALID_STRING_ID, WL_CRITICAL);
-	}
-
-	InvalidateWindowClassesData(WC_GAME_OPTIONS, 0);
-}
-
-/**
- * Check whether the road side may be changed.
- * @param new_value unused
- * @return true if the road side may be changed.
- */
-static bool CheckRoadSide(int32 &new_value)
-{
-	extern bool RoadVehiclesAreBuilt();
-	return _game_mode == GM_MENU || !RoadVehiclesAreBuilt();
-}
-
-/**
- * Conversion callback for _gameopt_settings_game.landscape
- * It converts (or try) between old values and the new ones,
- * without losing initial setting of the user
- * @param value that was read from config file
- * @return the "hopefully" converted value
- */
-static size_t ConvertLandscape(const char *value)
-{
-	/* try with the old values */
-	static std::vector<std::string> _old_landscape_values{"normal", "hilly", "desert", "candy"};
-	return OneOfManySettingDesc::ParseSingleValue(value, strlen(value), _old_landscape_values);
-}
-
-static bool CheckFreeformEdges(int32 &new_value)
-{
-	if (_game_mode == GM_MENU) return true;
-	if (new_value != 0) {
-		for (Ship *s : Ship::Iterate()) {
-			/* Check if there is a ship on the northern border. */
-			if (TileX(s->tile) == 0 || TileY(s->tile) == 0) {
-				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_EMPTY, INVALID_STRING_ID, WL_ERROR);
-				return false;
-			}
-		}
-		for (const BaseStation *st : BaseStation::Iterate()) {
-			/* Check if there is a non-deleted buoy on the northern border. */
-			if (st->IsInUse() && (TileX(st->xy) == 0 || TileY(st->xy) == 0)) {
-				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_EMPTY, INVALID_STRING_ID, WL_ERROR);
-				return false;
-			}
-		}
-	} else {
-		for (uint i = 0; i < MapMaxX(); i++) {
-			if (TileHeight(TileXY(i, 1)) != 0) {
-				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
-				return false;
-			}
-		}
-		for (uint i = 1; i < MapMaxX(); i++) {
-			if (!IsTileType(TileXY(i, MapMaxY() - 1), MP_WATER) || TileHeight(TileXY(1, MapMaxY())) != 0) {
-				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
-				return false;
-			}
-		}
-		for (uint i = 0; i < MapMaxY(); i++) {
-			if (TileHeight(TileXY(1, i)) != 0) {
-				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
-				return false;
-			}
-		}
-		for (uint i = 1; i < MapMaxY(); i++) {
-			if (!IsTileType(TileXY(MapMaxX() - 1, i), MP_WATER) || TileHeight(TileXY(MapMaxX(), i)) != 0) {
-				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
-				return false;
-			}
-		}
-	}
-	return true;
-}
-
-static void UpdateFreeformEdges(int32 new_value)
-{
-	if (_game_mode == GM_MENU) return;
-
-	if (new_value != 0) {
-		for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
-		for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
-	} else {
-		/* Make tiles at the border water again. */
-		for (uint i = 0; i < MapMaxX(); i++) {
-			SetTileHeight(TileXY(i, 0), 0);
-			SetTileType(TileXY(i, 0), MP_WATER);
-		}
-		for (uint i = 0; i < MapMaxY(); i++) {
-			SetTileHeight(TileXY(0, i), 0);
-			SetTileType(TileXY(0, i), MP_WATER);
-		}
-	}
-	MarkWholeScreenDirty();
-}
-
-/**
- * Changing the setting "allow multiple NewGRF sets" is not allowed
- * if there are vehicles.
- */
-static bool CheckDynamicEngines(int32 &new_value)
-{
-	if (_game_mode == GM_MENU) return true;
-
-	if (!EngineOverrideManager::ResetToCurrentNewGRFConfig()) {
-		ShowErrorMessage(STR_CONFIG_SETTING_DYNAMIC_ENGINES_EXISTING_VEHICLES, INVALID_STRING_ID, WL_ERROR);
-		return false;
-	}
-
-	return true;
-}
-
-static bool CheckMaxHeightLevel(int32 &new_value)
-{
-	if (_game_mode == GM_NORMAL) return false;
-	if (_game_mode != GM_EDITOR) return true;
-
-	/* Check if at least one mountain on the map is higher than the new value.
-	 * If yes, disallow the change. */
-	for (TileIndex t = 0; t < MapSize(); t++) {
-		if ((int32)TileHeight(t) > new_value) {
-			ShowErrorMessage(STR_CONFIG_SETTING_TOO_HIGH_MOUNTAIN, INVALID_STRING_ID, WL_ERROR);
-			/* Return old, unchanged value */
-			return false;
-		}
-	}
-
-	return true;
-}
-
-static void StationCatchmentChanged(int32 new_value)
-{
-	Station::RecomputeCatchmentForAll();
-	MarkWholeScreenDirty();
-}
-
-static void MaxVehiclesChanged(int32 new_value)
-{
-	InvalidateWindowClassesData(WC_BUILD_TOOLBAR);
-	MarkWholeScreenDirty();
-}
-
-static void InvalidateShipPathCache(int32 new_value)
-{
-	for (Ship *s : Ship::Iterate()) {
-		s->path.clear();
-	}
-}
-
-/**
- * Replace a passwords that are a literal asterisk with an empty string.
- * @param newval The new string value for this password field.
- * @return Always true.
- */
-static bool ReplaceAsteriskWithEmptyPassword(std::string &newval)
-{
-	if (newval.compare("*") == 0) newval.clear();
-	return true;
-}
-
-/** Update the game info, and send it to the clients when we are running as a server. */
-static void UpdateClientConfigValues()
-{
-	NetworkServerUpdateGameInfo();
-	if (_network_server) NetworkServerSendConfigUpdate();
-}
-
-/* End - Callback Functions */
-
 /**
  * Prepare for reading and old diff_custom by zero-ing the memory.
  */
diff --git a/src/settings_table.cpp b/src/settings_table.cpp
new file mode 100644
index 000000000..bc1e588cd
--- /dev/null
+++ b/src/settings_table.cpp
@@ -0,0 +1,473 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @file settings_table.cpp The tables of all the settings as well as the implementation of most of their callbacks.
+ */
+
+#include "stdafx.h"
+#include "settings_table.h"
+#include "currency.h"
+#include "screenshot.h"
+#include "network/network.h"
+#include "network/network_func.h"
+#include "pathfinder/pathfinder_type.h"
+#include "genworld.h"
+#include "train.h"
+#include "news_func.h"
+#include "window_func.h"
+#include "company_func.h"
+#if defined(WITH_FREETYPE) || defined(_WIN32) || defined(WITH_COCOA)
+#define HAS_TRUETYPE_FONT
+#include "fontcache.h"
+#endif
+#include "textbuf_gui.h"
+#include "rail_gui.h"
+#include "elrail_func.h"
+#include "error.h"
+#include "town.h"
+#include "video/video_driver.hpp"
+#include "sound/sound_driver.hpp"
+#include "music/music_driver.hpp"
+#include "blitter/factory.hpp"
+#include "base_media_base.h"
+#include "ai/ai_config.hpp"
+#include "ai/ai.hpp"
+#include "game/game_config.hpp"
+#include "ship.h"
+#include "smallmap_gui.h"
+#include "roadveh.h"
+#include "vehicle_func.h"
+#include "void_map.h"
+
+#include "table/strings.h"
+#include "table/settings.h"
+
+#include "safeguards.h"
+
+SettingTable _settings{ _settings_table };
+SettingTable _network_settings{ _network_settings_table };
+SettingTable _network_private_settings{ _network_private_settings_table };
+SettingTable _network_secrets_settings{ _network_secrets_settings_table };
+
+SettingTable _company_settings{ _company_settings_table };
+SettingTable _currency_settings{ _currency_settings_table };
+SettingTable _gameopt_settings{ _gameopt_settings_table };
+SettingTable _misc_settings{ _misc_settings_table };
+SettingTable _window_settings{ _window_settings_table };
+#if defined(_WIN32) && !defined(DEDICATED)
+SettingTable _win32_settings{ _win32_settings_table };
+#endif /* _WIN32 */
+
+
+/* Begin - Callback Functions for the various settings. */
+
+/** Reposition the main toolbar as the setting changed. */
+static void v_PositionMainToolbar(int32 new_value)
+{
+	if (_game_mode != GM_MENU) PositionMainToolbar(nullptr);
+}
+
+/** Reposition the statusbar as the setting changed. */
+static void v_PositionStatusbar(int32 new_value)
+{
+	if (_game_mode != GM_MENU) {
+		PositionStatusbar(nullptr);
+		PositionNewsMessage(nullptr);
+		PositionNetworkChatWindow(nullptr);
+	}
+}
+
+/**
+ * Redraw the smallmap after a colour scheme change.
+ * @param p1 Callback parameter.
+ */
+static void RedrawSmallmap(int32 new_value)
+{
+	BuildLandLegend();
+	BuildOwnerLegend();
+	SetWindowClassesDirty(WC_SMALLMAP);
+}
+
+static void StationSpreadChanged(int32 p1)
+{
+	InvalidateWindowData(WC_SELECT_STATION, 0);
+	InvalidateWindowData(WC_BUILD_STATION, 0);
+}
+
+static void CloseSignalGUI(int32 new_value)
+{
+	if (new_value == 0) {
+		CloseWindowByClass(WC_BUILD_SIGNAL);
+	}
+}
+
+static void UpdateConsists(int32 new_value)
+{
+	for (Train *t : Train::Iterate()) {
+		/* Update the consist of all trains so the maximum speed is set correctly. */
+		if (t->IsFrontEngine() || t->IsFreeWagon()) t->ConsistChanged(CCF_TRACK);
+	}
+	InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
+}
+
+/* Check service intervals of vehicles, newvalue is value of % or day based servicing */
+static void UpdateAllServiceInterval(int32 new_value)
+{
+	bool update_vehicles;
+	VehicleDefaultSettings *vds;
+	if (_game_mode == GM_MENU || !Company::IsValidID(_current_company)) {
+		vds = &_settings_client.company.vehicle;
+		update_vehicles = false;
+	} else {
+		vds = &Company::Get(_current_company)->settings.vehicle;
+		update_vehicles = true;
+	}
+
+	if (new_value != 0) {
+		vds->servint_trains   = 50;
+		vds->servint_roadveh  = 50;
+		vds->servint_aircraft = 50;
+		vds->servint_ships    = 50;
+	} else {
+		vds->servint_trains   = 150;
+		vds->servint_roadveh  = 150;
+		vds->servint_aircraft = 100;
+		vds->servint_ships    = 360;
+	}
+
+	if (update_vehicles) {
+		const Company *c = Company::Get(_current_company);
+		for (Vehicle *v : Vehicle::Iterate()) {
+			if (v->owner == _current_company && v->IsPrimaryVehicle() && !v->ServiceIntervalIsCustom()) {
+				v->SetServiceInterval(CompanyServiceInterval(c, v->type));
+				v->SetServiceIntervalIsPercent(new_value != 0);
+			}
+		}
+	}
+
+	SetWindowClassesDirty(WC_VEHICLE_DETAILS);
+}
+
+static bool CanUpdateServiceInterval(VehicleType type, int32 &new_value)
+{
+	VehicleDefaultSettings *vds;
+	if (_game_mode == GM_MENU || !Company::IsValidID(_current_company)) {
+		vds = &_settings_client.company.vehicle;
+	} else {
+		vds = &Company::Get(_current_company)->settings.vehicle;
+	}
+
+	/* Test if the interval is valid */
+	int32 interval = GetServiceIntervalClamped(new_value, vds->servint_ispercent);
+	return interval == new_value;
+}
+
+static void UpdateServiceInterval(VehicleType type, int32 new_value)
+{
+	if (_game_mode != GM_MENU && Company::IsValidID(_current_company)) {
+		for (Vehicle *v : Vehicle::Iterate()) {
+			if (v->owner == _current_company && v->type == type && v->IsPrimaryVehicle() && !v->ServiceIntervalIsCustom()) {
+				v->SetServiceInterval(new_value);
+			}
+		}
+	}
+
+	SetWindowClassesDirty(WC_VEHICLE_DETAILS);
+}
+
+static void TrainAccelerationModelChanged(int32 new_value)
+{
+	for (Train *t : Train::Iterate()) {
+		if (t->IsFrontEngine()) {
+			t->tcache.cached_max_curve_speed = t->GetCurveSpeedLimit();
+			t->UpdateAcceleration();
+		}
+	}
+
+	/* These windows show acceleration values only when realistic acceleration is on. They must be redrawn after a setting change. */
+	SetWindowClassesDirty(WC_ENGINE_PREVIEW);
+	InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
+	SetWindowClassesDirty(WC_VEHICLE_DETAILS);
+}
+
+/**
+ * This function updates the train acceleration cache after a steepness change.
+ * @param new_value Unused new value of setting.
+ */
+static void TrainSlopeSteepnessChanged(int32 new_value)
+{
+	for (Train *t : Train::Iterate()) {
+		if (t->IsFrontEngine()) t->CargoChanged();
+	}
+}
+
+/**
+ * This function updates realistic acceleration caches when the setting "Road vehicle acceleration model" is set.
+ * @param new_value Unused new value of setting.
+ */
+static void RoadVehAccelerationModelChanged(int32 new_value)
+{
+	if (_settings_game.vehicle.roadveh_acceleration_model != AM_ORIGINAL) {
+		for (RoadVehicle *rv : RoadVehicle::Iterate()) {
+			if (rv->IsFrontEngine()) {
+				rv->CargoChanged();
+			}
+		}
+	}
+
+	/* These windows show acceleration values only when realistic acceleration is on. They must be redrawn after a setting change. */
+	SetWindowClassesDirty(WC_ENGINE_PREVIEW);
+	InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
+	SetWindowClassesDirty(WC_VEHICLE_DETAILS);
+}
+
+/**
+ * This function updates the road vehicle acceleration cache after a steepness change.
+ * @param new_value Unused new value of setting.
+ */
+static void RoadVehSlopeSteepnessChanged(int32 new_value)
+{
+	for (RoadVehicle *rv : RoadVehicle::Iterate()) {
+		if (rv->IsFrontEngine()) rv->CargoChanged();
+	}
+}
+
+static void TownFoundingChanged(int32 new_value)
+{
+	if (_game_mode != GM_EDITOR && _settings_game.economy.found_town == TF_FORBIDDEN) {
+		CloseWindowById(WC_FOUND_TOWN, 0);
+	} else {
+		InvalidateWindowData(WC_FOUND_TOWN, 0);
+	}
+}
+
+static void ZoomMinMaxChanged(int32 new_value)
+{
+	extern void ConstrainAllViewportsZoom();
+	ConstrainAllViewportsZoom();
+	GfxClearSpriteCache();
+	if (_settings_client.gui.zoom_min > _gui_zoom) {
+		/* Restrict GUI zoom if it is no longer available. */
+		_gui_zoom = _settings_client.gui.zoom_min;
+		UpdateCursorSize();
+		LoadStringWidthTable();
+	}
+}
+
+static void SpriteZoomMinChanged(int32 new_value)
+{
+	GfxClearSpriteCache();
+	/* Force all sprites to redraw at the new chosen zoom level */
+	MarkWholeScreenDirty();
+}
+
+/**
+ * Update any possible saveload window and delete any newgrf dialogue as
+ * its widget parts might change. Reinit all windows as it allows access to the
+ * newgrf debug button.
+ * @param new_value unused.
+ */
+static void InvalidateNewGRFChangeWindows(int32 new_value)
+{
+	InvalidateWindowClassesData(WC_SAVELOAD);
+	CloseWindowByClass(WC_GAME_OPTIONS);
+	ReInitAllWindows(_gui_zoom_cfg);
+}
+
+static void InvalidateCompanyLiveryWindow(int32 new_value)
+{
+	InvalidateWindowClassesData(WC_COMPANY_COLOUR, -1);
+	ResetVehicleColourMap();
+}
+
+static void DifficultyNoiseChange(int32 new_value)
+{
+	if (_game_mode == GM_NORMAL) {
+		UpdateAirportsNoise();
+		if (_settings_game.economy.station_noise_level) {
+			InvalidateWindowClassesData(WC_TOWN_VIEW, 0);
+		}
+	}
+}
+
+static void MaxNoAIsChange(int32 new_value)
+{
+	if (GetGameSettings().difficulty.max_no_competitors != 0 &&
+			AI::GetInfoList()->size() == 0 &&
+			(!_networking || _network_server)) {
+		ShowErrorMessage(STR_WARNING_NO_SUITABLE_AI, INVALID_STRING_ID, WL_CRITICAL);
+	}
+
+	InvalidateWindowClassesData(WC_GAME_OPTIONS, 0);
+}
+
+/**
+ * Check whether the road side may be changed.
+ * @param new_value unused
+ * @return true if the road side may be changed.
+ */
+static bool CheckRoadSide(int32 &new_value)
+{
+	extern bool RoadVehiclesAreBuilt();
+	return _game_mode == GM_MENU || !RoadVehiclesAreBuilt();
+}
+
+/**
+ * Conversion callback for _gameopt_settings_game.landscape
+ * It converts (or try) between old values and the new ones,
+ * without losing initial setting of the user
+ * @param value that was read from config file
+ * @return the "hopefully" converted value
+ */
+static size_t ConvertLandscape(const char *value)
+{
+	/* try with the old values */
+	static std::vector<std::string> _old_landscape_values{"normal", "hilly", "desert", "candy"};
+	return OneOfManySettingDesc::ParseSingleValue(value, strlen(value), _old_landscape_values);
+}
+
+static bool CheckFreeformEdges(int32 &new_value)
+{
+	if (_game_mode == GM_MENU) return true;
+	if (new_value != 0) {
+		for (Ship *s : Ship::Iterate()) {
+			/* Check if there is a ship on the northern border. */
+			if (TileX(s->tile) == 0 || TileY(s->tile) == 0) {
+				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_EMPTY, INVALID_STRING_ID, WL_ERROR);
+				return false;
+			}
+		}
+		for (const BaseStation *st : BaseStation::Iterate()) {
+			/* Check if there is a non-deleted buoy on the northern border. */
+			if (st->IsInUse() && (TileX(st->xy) == 0 || TileY(st->xy) == 0)) {
+				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_EMPTY, INVALID_STRING_ID, WL_ERROR);
+				return false;
+			}
+		}
+	} else {
+		for (uint i = 0; i < MapMaxX(); i++) {
+			if (TileHeight(TileXY(i, 1)) != 0) {
+				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
+				return false;
+			}
+		}
+		for (uint i = 1; i < MapMaxX(); i++) {
+			if (!IsTileType(TileXY(i, MapMaxY() - 1), MP_WATER) || TileHeight(TileXY(1, MapMaxY())) != 0) {
+				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
+				return false;
+			}
+		}
+		for (uint i = 0; i < MapMaxY(); i++) {
+			if (TileHeight(TileXY(1, i)) != 0) {
+				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
+				return false;
+			}
+		}
+		for (uint i = 1; i < MapMaxY(); i++) {
+			if (!IsTileType(TileXY(MapMaxX() - 1, i), MP_WATER) || TileHeight(TileXY(MapMaxX(), i)) != 0) {
+				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
+				return false;
+			}
+		}
+	}
+	return true;
+}
+
+static void UpdateFreeformEdges(int32 new_value)
+{
+	if (_game_mode == GM_MENU) return;
+
+	if (new_value != 0) {
+		for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
+		for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
+	} else {
+		/* Make tiles at the border water again. */
+		for (uint i = 0; i < MapMaxX(); i++) {
+			SetTileHeight(TileXY(i, 0), 0);
+			SetTileType(TileXY(i, 0), MP_WATER);
+		}
+		for (uint i = 0; i < MapMaxY(); i++) {
+			SetTileHeight(TileXY(0, i), 0);
+			SetTileType(TileXY(0, i), MP_WATER);
+		}
+	}
+	MarkWholeScreenDirty();
+}
+
+/**
+ * Changing the setting "allow multiple NewGRF sets" is not allowed
+ * if there are vehicles.
+ */
+static bool CheckDynamicEngines(int32 &new_value)
+{
+	if (_game_mode == GM_MENU) return true;
+
+	if (!EngineOverrideManager::ResetToCurrentNewGRFConfig()) {
+		ShowErrorMessage(STR_CONFIG_SETTING_DYNAMIC_ENGINES_EXISTING_VEHICLES, INVALID_STRING_ID, WL_ERROR);
+		return false;
+	}
+
+	return true;
+}
+
+static bool CheckMaxHeightLevel(int32 &new_value)
+{
+	if (_game_mode == GM_NORMAL) return false;
+	if (_game_mode != GM_EDITOR) return true;
+
+	/* Check if at least one mountain on the map is higher than the new value.
+	 * If yes, disallow the change. */
+	for (TileIndex t = 0; t < MapSize(); t++) {
+		if ((int32)TileHeight(t) > new_value) {
+			ShowErrorMessage(STR_CONFIG_SETTING_TOO_HIGH_MOUNTAIN, INVALID_STRING_ID, WL_ERROR);
+			/* Return old, unchanged value */
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static void StationCatchmentChanged(int32 new_value)
+{
+	Station::RecomputeCatchmentForAll();
+	MarkWholeScreenDirty();
+}
+
+static void MaxVehiclesChanged(int32 new_value)
+{
+	InvalidateWindowClassesData(WC_BUILD_TOOLBAR);
+	MarkWholeScreenDirty();
+}
+
+static void InvalidateShipPathCache(int32 new_value)
+{
+	for (Ship *s : Ship::Iterate()) {
+		s->path.clear();
+	}
+}
+
+/**
+ * Replace a passwords that are a literal asterisk with an empty string.
+ * @param newval The new string value for this password field.
+ * @return Always true.
+ */
+static bool ReplaceAsteriskWithEmptyPassword(std::string &newval)
+{
+	if (newval.compare("*") == 0) newval.clear();
+	return true;
+}
+
+/** Update the game info, and send it to the clients when we are running as a server. */
+static void UpdateClientConfigValues()
+{
+	NetworkServerUpdateGameInfo();
+	if (_network_server) NetworkServerSendConfigUpdate();
+}
+
+/* End - Callback Functions */
diff --git a/src/settings_table.h b/src/settings_table.h
new file mode 100644
index 000000000..ace0ec7a2
--- /dev/null
+++ b/src/settings_table.h
@@ -0,0 +1,38 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @file settings_table.h Definition of the configuration tables of the settings.
+ */
+
+#ifndef SETTINGS_TABLE_H
+#define SETTINGS_TABLE_H
+
+#include <array>
+#include "settings_internal.h"
+
+typedef span<const SettingVariant> SettingTable;
+
+extern SettingTable _settings;
+extern SettingTable _network_settings;
+extern SettingTable _network_private_settings;
+extern SettingTable _network_secrets_settings;
+
+extern SettingTable _company_settings;
+extern SettingTable _currency_settings;
+extern SettingTable _gameopt_settings;
+extern SettingTable _misc_settings;
+extern SettingTable _window_settings;
+#if defined(_WIN32) && !defined(DEDICATED)
+extern SettingTable _win32_settings;
+#endif /* _WIN32 */
+
+static const uint GAME_DIFFICULTY_NUM = 18;
+extern const std::array<std::string, GAME_DIFFICULTY_NUM> _old_diff_settings;
+extern uint16 _old_diff_custom[GAME_DIFFICULTY_NUM];
+
+#endif /* SETTINGS_TABLE_H */
diff --git a/src/table/settings/company_settings.ini b/src/table/settings/company_settings.ini
index e5019305f..52920e6e6 100644
--- a/src/table/settings/company_settings.ini
+++ b/src/table/settings/company_settings.ini
@@ -12,7 +12,7 @@ static void UpdateAllServiceInterval(int32 new_value);
 static bool CanUpdateServiceInterval(VehicleType type, int32 &new_value);
 static void UpdateServiceInterval(VehicleType type, int32 new_value);
 
-static const SettingVariant _company_settings[] = {
+static const SettingVariant _company_settings_table[] = {
 [post-amble]
 };
 [templates]
diff --git a/src/table/settings/currency_settings.ini b/src/table/settings/currency_settings.ini
index d0950db8e..03c6425b2 100644
--- a/src/table/settings/currency_settings.ini
+++ b/src/table/settings/currency_settings.ini
@@ -7,7 +7,7 @@
 ; Settings for the in-game custom currency.
 
 [pre-amble]
-static const SettingVariant _currency_settings[] = {
+static const SettingVariant _currency_settings_table[] = {
 [post-amble]
 };
 [templates]
diff --git a/src/table/settings/gameopt_settings.ini b/src/table/settings/gameopt_settings.ini
index a30400e85..83e7c6395 100644
--- a/src/table/settings/gameopt_settings.ini
+++ b/src/table/settings/gameopt_settings.ini
@@ -14,9 +14,8 @@
 ; be saved in their new place.
 
 [pre-amble]
-static const uint GAME_DIFFICULTY_NUM = 18;
-static const std::array<std::string, GAME_DIFFICULTY_NUM> _old_diff_settings{"max_no_competitors", "competitor_start_time", "number_towns", "industry_density", "max_loan", "initial_interest", "vehicle_costs", "competitor_speed", "competitor_intelligence", "vehicle_breakdowns", "subsidy_multiplier", "construction_cost", "terrain_type", "quantity_sea_lakes", "economy", "line_reverse_mode", "disasters", "town_council_tolerance"};
-static uint16 _old_diff_custom[GAME_DIFFICULTY_NUM];
+const std::array<std::string, GAME_DIFFICULTY_NUM> _old_diff_settings{"max_no_competitors", "competitor_start_time", "number_towns", "industry_density", "max_loan", "initial_interest", "vehicle_costs", "competitor_speed", "competitor_intelligence", "vehicle_breakdowns", "subsidy_multiplier", "construction_cost", "terrain_type", "quantity_sea_lakes", "economy", "line_reverse_mode", "disasters", "town_council_tolerance"};
+uint16 _old_diff_custom[GAME_DIFFICULTY_NUM];
 uint8 _old_diff_level;                                 ///< Old difficulty level from old savegames
 uint8 _old_units;                                      ///< Old units from old savegames
 
@@ -33,7 +32,7 @@ static std::initializer_list<const char*> _osk_activation{"disabled", "double",
 static std::initializer_list<const char*> _settings_profiles{"easy", "medium", "hard"};
 static std::initializer_list<const char*> _news_display{ "off", "summarized", "full"};
 
-static const SettingVariant _gameopt_settings[] = {
+static const SettingVariant _gameopt_settings_table[] = {
 /* In version 4 a new difficulty setting has been added to the difficulty settings,
  * town attitude towards demolishing. Needs special handling because some dimwit thought
  * it funny to have the GameDifficulty struct be an array while it is a struct of
diff --git a/src/table/settings/misc_settings.ini b/src/table/settings/misc_settings.ini
index 9f73573b2..daca4a817 100644
--- a/src/table/settings/misc_settings.ini
+++ b/src/table/settings/misc_settings.ini
@@ -20,7 +20,7 @@ extern bool _allow_hidpi_window;
 #define WITHOUT_COCOA
 #endif
 
-static const SettingVariant _misc_settings[] = {
+static const SettingVariant _misc_settings_table[] = {
 [post-amble]
 };
 [templates]
diff --git a/src/table/settings/network_private_settings.ini b/src/table/settings/network_private_settings.ini
index 76fbd373a..cae43330f 100644
--- a/src/table/settings/network_private_settings.ini
+++ b/src/table/settings/network_private_settings.ini
@@ -7,7 +7,7 @@
 ; Network settings as stored in the private configuration file ("private.cfg").
 
 [pre-amble]
-static const SettingVariant _network_private_settings[] = {
+static const SettingVariant _network_private_settings_table[] = {
 [post-amble]
 };
 [templates]
diff --git a/src/table/settings/network_secrets_settings.ini b/src/table/settings/network_secrets_settings.ini
index a408bad40..fced9240e 100644
--- a/src/table/settings/network_secrets_settings.ini
+++ b/src/table/settings/network_secrets_settings.ini
@@ -9,7 +9,7 @@
 [pre-amble]
 static bool ReplaceAsteriskWithEmptyPassword(std::string &newval);
 
-static const SettingVariant _network_secrets_settings[] = {
+static const SettingVariant _network_secrets_settings_table[] = {
 [post-amble]
 };
 [templates]
diff --git a/src/table/settings/network_settings.ini b/src/table/settings/network_settings.ini
index 1317edbc7..45459b6e1 100644
--- a/src/table/settings/network_settings.ini
+++ b/src/table/settings/network_settings.ini
@@ -9,7 +9,7 @@
 [pre-amble]
 static void UpdateClientConfigValues();
 
-static const SettingVariant _network_settings[] = {
+static const SettingVariant _network_settings_table[] = {
 [post-amble]
 };
 [templates]
diff --git a/src/table/settings/settings.ini b/src/table/settings/settings.ini
index fae6e5636..984668e51 100644
--- a/src/table/settings/settings.ini
+++ b/src/table/settings/settings.ini
@@ -46,7 +46,7 @@ static void InvalidateShipPathCache(int32 new_value);
  * assigns its own value. If the setting was company-based, that would mean that
  * vehicles could decide on different moments that they are heading back to a
  * service depot, causing desyncs on a massive scale. */
-static const SettingVariant _settings[] = {
+static const SettingVariant _settings_table[] = {
 [post-amble]
 };
 [templates]
diff --git a/src/table/settings/win32_settings.ini b/src/table/settings/win32_settings.ini
index 51b579629..4256528dd 100644
--- a/src/table/settings/win32_settings.ini
+++ b/src/table/settings/win32_settings.ini
@@ -12,7 +12,7 @@
 #if defined(_WIN32) && !defined(DEDICATED)
 extern bool _window_maximize;
 
-static const SettingVariant _win32_settings[] = {
+static const SettingVariant _win32_settings_table[] = {
 [post-amble]
 };
 #endif /* _WIN32 */
diff --git a/src/table/settings/window_settings.ini b/src/table/settings/window_settings.ini
index d9327aa92..aba8d3dba 100644
--- a/src/table/settings/window_settings.ini
+++ b/src/table/settings/window_settings.ini
@@ -9,7 +9,7 @@
 
 [pre-amble]
 
-static const SettingVariant _window_settings[] = {
+static const SettingVariant _window_settings_table[] = {
 [post-amble]
 };
 [templates]