Merge branch 'master' into jgrpp

# Conflicts:
#	src/cargopacket.h
#	src/cargotype.h
#	src/station_base.h
#	src/station_cmd.cpp
#	src/timer/timer_game_common.h
#	src/town.h

COMPILING.md

@@ -29,7 +29,7 @@ open most older savegames or use the content downloading system.
 
 ## Windows
 
-You need Microsoft Visual Studio 2017 or more recent.
+You need Microsoft Visual Studio 2022 or more recent.
 
 You can download the free Visual Studio Community Edition from Microsoft at
 https://visualstudio.microsoft.com/vs/community/.
@@ -65,7 +65,7 @@ To install both the x64 (64bit) and x86 (32bit) variants (though only one is nec
 
 You can open the folder (as a CMake project). CMake will be detected, and you can compile from there.
 If libraries are installed but not found, you need to set VCPKG_TARGET_TRIPLET in CMake parameters.
-For Visual Studio 2017 you also need to set CMAKE_TOOLCHAIN_FILE.
+For Visual Studio 2022 you also need to set CMAKE_TOOLCHAIN_FILE.
 (Typical values are shown in the MSVC project file command line example)
 
 Alternatively, you can create a MSVC project file via CMake. For this
@@ -75,7 +75,7 @@ that comes with vcpkg. After that, you can run something similar to this:
 ```powershell
 mkdir build
 cd build
-cmake.exe .. -G"Visual Studio 16 2019" -DCMAKE_TOOLCHAIN_FILE="<location of vcpkg>\vcpkg\scripts\buildsystems\vcpkg.cmake" -DVCPKG_TARGET_TRIPLET="x64-windows-static"
+cmake.exe .. -G"Visual Studio 17 2022" -DCMAKE_TOOLCHAIN_FILE="<location of vcpkg>\vcpkg\scripts\buildsystems\vcpkg.cmake" -DVCPKG_TARGET_TRIPLET="x64-windows-static"
 ```
 
 Change `<location of vcpkg>` to where you have installed vcpkg. After this
@@ -83,7 +83,7 @@ in the build folder are MSVC project files. MSVC can rebuild the project
 files himself via the `ZERO_CHECK` project.
 
 ## All other platforms
-Minimum required version of CMake is 3.9.
+Minimum required version of CMake is 3.16.
 By default this produces a Debug build with assertations enabled.
 This is a far slower build than release builds.
 
@@ -115,9 +115,9 @@ builds.
 
 ## Supported compilers
 
-Every compiler that is supported by CMake and supports C++17, should be
+Every compiler that is supported by CMake and supports C++20, should be
 able to compile OpenTTD. As the exact list of compilers changes constantly,
-we refer to the compiler manual to see if it supports C++17, and to CMake
+we refer to the compiler manual to see if it supports C++20, and to CMake
 to see if it supports your compiler.
 
 ## Compilation of base sets

src/bootstrap_gui.cpp

@@ -290,10 +290,10 @@ public:
 #	include "video/video_driver.hpp"
 
 class BootstrapEmscripten : public ContentCallback {
-	bool downloading{false};
+	bool downloading = false;
-	uint total_files{0};
+	uint total_files = 0;
-	uint total_bytes{0};
+	uint total_bytes = 0;
-	uint downloaded_bytes{0};
+	uint downloaded_bytes = 0;
 
 public:
 	BootstrapEmscripten()

src/build_vehicle_gui.cpp

@@ -1658,7 +1658,7 @@ struct BuildVehicleWindow : BuildVehicleWindowBase {
 
 		/* Select the first unshaded engine in the list as default when opening the window */
 		EngineID engine = INVALID_ENGINE;
-		auto it = std::find_if(this->eng_list.begin(), this->eng_list.end(), [&](GUIEngineListItem &item){ return (item.flags & EngineDisplayFlags::Shaded) == EngineDisplayFlags::None; });
+		auto it = std::find_if(this->eng_list.begin(), this->eng_list.end(), [&](GUIEngineListItem &item) { return (item.flags & EngineDisplayFlags::Shaded) == EngineDisplayFlags::None; });
 		if (it != this->eng_list.end()) engine = it->engine_id;
 		this->SelectEngine(engine);
 	}

src/cargotype.h

@@ -67,21 +67,21 @@ static const uint TOWN_PRODUCTION_DIVISOR = 256;
 
 /** Specification of a cargo type. */
 struct CargoSpec {
-	CargoLabel label;                     ///< Unique label of the cargo type.
+	CargoLabel label;                      ///< Unique label of the cargo type.
-	uint8_t bitnum{INVALID_CARGO_BITNUM}; ///< Cargo bit number, is #INVALID_CARGO_BITNUM for a non-used spec.
+	uint8_t bitnum = INVALID_CARGO_BITNUM; ///< Cargo bit number, is #INVALID_CARGO_BITNUM for a non-used spec.
 	uint8_t legend_colour;
 	uint8_t rating_colour;
-	uint8_t weight;                       ///< Weight of a single unit of this cargo type in 1/16 ton (62.5 kg).
+	uint8_t weight;                        ///< Weight of a single unit of this cargo type in 1/16 ton (62.5 kg).
-	uint16_t multiplier{0x100};           ///< Capacity multiplier for vehicles. (8 fractional bits)
+	uint16_t multiplier = 0x100;           ///< Capacity multiplier for vehicles. (8 fractional bits)
-	uint16_t classes;                     ///< Classes of this cargo type. @see CargoClass
+	uint16_t classes;                      ///< Classes of this cargo type. @see CargoClass
-	int32_t initial_payment;              ///< Initial payment rate before inflation is applied.
+	int32_t initial_payment;               ///< Initial payment rate before inflation is applied.
 	uint8_t transit_periods[2];
 
-	bool is_freight;                      ///< Cargo type is considered to be freight (affects train freight multiplier).
+	bool is_freight;                                               ///< Cargo type is considered to be freight (affects train freight multiplier).
-	TownAcceptanceEffect town_acceptance_effect;              ///< The effect that delivering this cargo type has on towns. Also affects destination of subsidies.
+	TownAcceptanceEffect town_acceptance_effect;                   ///< The effect that delivering this cargo type has on towns. Also affects destination of subsidies.
-	TownProductionEffect town_production_effect{INVALID_TPE}; ///< The effect on town cargo production.
+	TownProductionEffect town_production_effect = INVALID_TPE;     ///< The effect on town cargo production.
-	uint16_t town_production_multiplier{TOWN_PRODUCTION_DIVISOR}; ///< Town production multipler, if commanded by TownProductionEffect.
+	uint16_t town_production_multiplier = TOWN_PRODUCTION_DIVISOR; ///< Town production multipler, if commanded by TownProductionEffect.
-	uint8_t callback_mask;                ///< Bitmask of cargo callbacks that have to be called
+	uint8_t callback_mask;                                         ///< Bitmask of cargo callbacks that have to be called
 
 	StringID name;                        ///< Name of this type of cargo.
 	StringID name_single;                 ///< Name of a single entity of this type of cargo.

src/console_cmds.cpp

@@ -2440,10 +2440,10 @@ DEF_CONSOLE_CMD(ConFont)
 		IConsolePrint(CC_HELP, "  Print out the fonts configuration.");
 		IConsolePrint(CC_HELP, "  The \"Currently active\" configuration is the one actually in effect (after interface scaling and replacing unavailable fonts).");
 		IConsolePrint(CC_HELP, "  The \"Requested\" configuration is the one requested via console command or config file.");
-		IConsolePrint(CC_HELP, "Usage 'font [medium|small|large|mono] [<font name>] [<size>] [aa|noaa]'.");
+		IConsolePrint(CC_HELP, "Usage 'font [medium|small|large|mono] [<font name>] [<size>]'.");
 		IConsolePrint(CC_HELP, "  Change the configuration for a font.");
 		IConsolePrint(CC_HELP, "  Omitting an argument will keep the current value.");
-		IConsolePrint(CC_HELP, "  Set <font name> to \"\" for the default font. Note that <size> and aa/noaa have no effect if the default font is in use, and fixed defaults are used instead.");
+		IConsolePrint(CC_HELP, "  Set <font name> to \"\" for the default font. Note that <size> has no effect if the default font is in use, and fixed defaults are used instead.");
 		IConsolePrint(CC_HELP, "  If the sprite font is enabled in Game Options, it is used instead of the default font.");
 		IConsolePrint(CC_HELP, "  The <size> is automatically multiplied by the current interface scaling.");
 		return true;
@@ -2461,38 +2461,23 @@ DEF_CONSOLE_CMD(ConFont)
 		FontCacheSubSetting *setting = GetFontCacheSubSetting(argfs);
 		std::string font = setting->font;
 		uint size = setting->size;
-		bool aa = setting->aa;
+		uint v;
-
 		uint8_t arg_index = 2;
-		/* We may encounter "aa" or "noaa" but it must be the last argument. */
+		/* For <name> we want a string. */
-		if (StrEqualsIgnoreCase(argv[arg_index], "aa") || StrEqualsIgnoreCase(argv[arg_index], "noaa")) {
+
-			aa = !StrStartsWithIgnoreCase(argv[arg_index++], "no");
+		if (!GetArgumentInteger(&v, argv[arg_index])) {
-			if (argc > arg_index) return false;
+			font = argv[arg_index++];
-		} else {
-			/* For <name> we want a string. */
-			uint v;
-			if (!GetArgumentInteger(&v, argv[arg_index])) {
-				font = argv[arg_index++];
-			}
 		}
 
 		if (argc > arg_index) {
 			/* For <size> we want a number. */
-			uint v;
 			if (GetArgumentInteger(&v, argv[arg_index])) {
 				size = v;
 				arg_index++;
 			}
 		}
 
-		if (argc > arg_index) {
+		SetFont(argfs, font, size);
-			/* Last argument must be "aa" or "noaa". */
-			if (!StrEqualsIgnoreCase(argv[arg_index], "aa") && !StrEqualsIgnoreCase(argv[arg_index], "noaa")) return false;
-			aa = !StrStartsWithIgnoreCase(argv[arg_index++], "no");
-			if (argc > arg_index) return false;
-		}
-
-		SetFont(argfs, font, size, aa);
 	}
 
 	for (FontSize fs = FS_BEGIN; fs < FS_END; fs++) {
@@ -2504,8 +2489,8 @@ DEF_CONSOLE_CMD(ConFont)
 			fc = FontCache::Get(fs);
 		}
 		IConsolePrint(CC_DEFAULT, "{} font:", FontSizeToName(fs));
-		IConsolePrint(CC_DEFAULT, "Currently active: \"{}\", size {}, {}", fc->GetFontName(), fc->GetFontSize(), GetFontAAState(fs) ? "aa" : "noaa");
+		IConsolePrint(CC_DEFAULT, "Currently active: \"{}\", size {}", fc->GetFontName(), fc->GetFontSize());
-		IConsolePrint(CC_DEFAULT, "Requested: \"{}\", size {}, {}", setting->font, setting->size, setting->aa ? "aa" : "noaa");
+		IConsolePrint(CC_DEFAULT, "Requested: \"{}\", size {}", setting->font, setting->size);
 	}
 
 	FontChanged();

src/fontcache.cpp

@@ -74,15 +74,15 @@ void UpdateFontHeightCache()
 }
 
 /* Check if a glyph should be rendered with anti-aliasing. */
-bool GetFontAAState(FontSize size, bool check_blitter)
+bool GetFontAAState()
 {
 	/* AA is only supported for 32 bpp */
-	if (check_blitter && BlitterFactory::GetCurrentBlitter()->GetScreenDepth() != 32) return false;
+	if (BlitterFactory::GetCurrentBlitter()->GetScreenDepth() != 32) return false;
 
-	return _fcsettings.global_aa || GetFontCacheSubSetting(size)->aa;
+	return _fcsettings.global_aa;
 }
 
-void SetFont(FontSize fontsize, const std::string &font, uint size, bool aa)
+void SetFont(FontSize fontsize, const std::string &font, uint size)
 {
 	FontCacheSubSetting *setting = GetFontCacheSubSetting(fontsize);
 	bool changed = false;
@@ -97,11 +97,6 @@ void SetFont(FontSize fontsize, const std::string &font, uint size, bool aa)
 		changed = true;
 	}
 
-	if (setting->aa != aa) {
-		setting->aa = aa;
-		changed = true;
-	}
-
 	if (!changed) return;
 
 	if (fontsize != FS_MONO) {
@@ -216,19 +211,6 @@ void UninitFontCache()
 #endif /* WITH_FREETYPE */
 }
 
-/**
- * Should any of the active fonts be anti-aliased?
- * @return True if any of the loaded fonts want anti-aliased drawing.
- */
-bool HasAntialiasedFonts()
-{
-	for (FontSize fs = FS_BEGIN; fs < FS_END; fs++) {
-		if (!FontCache::Get(fs)->IsBuiltInFont() && GetFontAAState(fs, false)) return true;
-	}
-
-	return false;
-}
-
 #if !defined(_WIN32) && !defined(__APPLE__) && !defined(WITH_FONTCONFIG) && !defined(WITH_COCOA)
 
 bool SetFallbackFont(FontCacheSettings *, const std::string &, int, MissingGlyphSearcher *) { return false; }

src/fontcache.h

@@ -211,7 +211,6 @@ inline bool GetDrawGlyphShadow(FontSize size)
 struct FontCacheSubSetting {
 	std::string font; ///< The name of the font, or path to the font.
 	uint size;        ///< The (requested) size of the font.
-	bool aa;          ///< Whether to do anti aliasing or not.
 
 	const void *os_handle = nullptr; ///< Optional native OS font info. Only valid during font search.
 };
@@ -246,9 +245,8 @@ inline FontCacheSubSetting *GetFontCacheSubSetting(FontSize fs)
 
 void InitFontCache(bool monospace);
 void UninitFontCache();
-bool HasAntialiasedFonts();
 
-bool GetFontAAState(FontSize size, bool check_blitter = true);
+bool GetFontAAState();
-void SetFont(FontSize fontsize, const std::string &font, uint size, bool aa);
+void SetFont(FontSize fontsize, const std::string &font, uint size);
 
 #endif /* FONTCACHE_H */

src/fontcache/truetypefontcache.cpp

@@ -91,7 +91,7 @@ void TrueTypeFontCache::SetGlyphPtr(GlyphID key, const GlyphEntry *glyph, bool d
 
 bool TrueTypeFontCache::GetDrawGlyphShadow()
 {
-	return this->fs == FS_NORMAL && GetFontAAState(FS_NORMAL);
+	return this->fs == FS_NORMAL && GetFontAAState();
 }
 
 uint TrueTypeFontCache::GetGlyphWidth(GlyphID key)
@@ -162,7 +162,7 @@ const Sprite *TrueTypeFontCache::GetGlyph(GlyphID key)
 		}
 	}
 
-	return this->InternalGetGlyph(key, GetFontAAState(this->fs));
+	return this->InternalGetGlyph(key, GetFontAAState());
 }
 
 const void *TrueTypeFontCache::GetFontTable(uint32_t tag, size_t &length)

src/genworld.cpp

@@ -115,6 +115,10 @@ static void _GenerateWorld()
 		IncreaseGeneratingWorldProgress(GWP_MAP_INIT);
 		/* Must start economy early because of the costs. */
 		StartupEconomy();
+		if (!CheckTownRoadTypes()) {
+			HandleGeneratingWorldAbortion();
+			return;
+		}
 
 		bool landscape_generated = false;
 

src/gfx_layout_icu.cpp

@@ -151,7 +151,7 @@ void ICURun::Shape(UChar *buff, size_t buff_length)
 {
 	auto hbfont = hb_ft_font_create_referenced(*(static_cast<const FT_Face *>(font->fc->GetOSHandle())));
 	/* Match the flags with how we render the glyphs. */
-	hb_ft_font_set_load_flags(hbfont, GetFontAAState(this->font->fc->GetSize()) ? FT_LOAD_TARGET_NORMAL : FT_LOAD_TARGET_MONO);
+	hb_ft_font_set_load_flags(hbfont, GetFontAAState() ? FT_LOAD_TARGET_NORMAL : FT_LOAD_TARGET_MONO);
 
 	/* ICU buffer is in UTF-16. */
 	auto hbbuf = hb_buffer_create();

src/gfxinit.cpp

@@ -325,7 +325,7 @@ static bool SwitchNewGRFBlitter()
 		if (c->palette & GRFP_BLT_32BPP) depth_wanted_by_grf = 32;
 	}
 	/* We need a 32bpp blitter for font anti-alias. */
-	if (HasAntialiasedFonts()) depth_wanted_by_grf = 32;
+	if (GetFontAAState()) depth_wanted_by_grf = 32;
 
 	/* Search the best blitter. */
 	static const struct {

src/lang/brazilian_portuguese.txt

@@ -446,7 +446,7 @@ STR_SETTINGS_MENU_CONFIG_SETTINGS_TREE                          :Configurações
 STR_SETTINGS_MENU_AI_SETTINGS                                   :Configurações de IA
 STR_SETTINGS_MENU_GAMESCRIPT_SETTINGS                           :Configurações de Script de Jogo
 STR_SETTINGS_MENU_NEWGRF_SETTINGS                               :Configurações de NewGRF
-STR_SETTINGS_MENU_SANDBOX_OPTIONS                               :Opções de trapaças
+STR_SETTINGS_MENU_SANDBOX_OPTIONS                               :Opções da sandbox
 STR_SETTINGS_MENU_TRANSPARENCY_OPTIONS                          :Opções de transparência
 STR_SETTINGS_MENU_TOWN_NAMES_DISPLAYED                          :Mostrar nomes de localidades
 STR_SETTINGS_MENU_STATION_NAMES_DISPLAYED                       :Mostrar nomes de estações
@@ -2242,7 +2242,7 @@ STR_HELP_WINDOW_BUGTRACKER                                      :{BLACK}Relatar
 STR_HELP_WINDOW_COMMUNITY                                       :{BLACK}Comunidade
 
 # Cheat window
-STR_CHEATS                                                      :{WHITE}Trapaças
+STR_CHEATS                                                      :{WHITE}Opções da Sandbox
 STR_CHEAT_MONEY                                                 :{LTBLUE}Aumentar dinheiro em {CURRENCY_LONG}
 STR_CHEAT_CHANGE_COMPANY                                        :{LTBLUE}Jogando como empresa: {ORANGE}{COMMA}
 STR_CHEAT_EXTRA_DYNAMITE                                        :{LTBLUE}Escavadeira mágica (remove indústrias, objetos estáticos): {ORANGE}{STRING}

src/lang/english.txt

@@ -5286,6 +5286,11 @@ STR_ERROR_NO_VEHICLES_AVAILABLE_AT_ALL_EXPLANATION              :{WHITE}Change y
 STR_ERROR_NO_VEHICLES_AVAILABLE_YET                             :{WHITE}No vehicles are available yet
 STR_ERROR_NO_VEHICLES_AVAILABLE_YET_EXPLANATION                 :{WHITE}Start a new game after {DATE_SHORT} or use a NewGRF that provides early vehicles
 
+STR_ERROR_NO_TOWN_ROADTYPES_AVAILABLE_AT_ALL                    :{WHITE}No town-buildable road types are available
+STR_ERROR_NO_TOWN_ROADTYPES_AVAILABLE_AT_ALL_EXPLANATION        :{WHITE}Change your NewGRF configuration
+STR_ERROR_NO_TOWN_ROADTYPES_AVAILABLE_YET                       :{WHITE}No town-buildable road types are available yet
+STR_ERROR_NO_TOWN_ROADTYPES_AVAILABLE_YET_EXPLANATION           :{WHITE}Start a new game after {DATE_SHORT} or use a NewGRF that provides early town-buildable road types
+
 # Specific vehicle errors
 STR_ERROR_CAN_T_MAKE_TRAIN_PASS_SIGNAL                          :{WHITE}Can't make train pass signal at danger...
 STR_ERROR_CAN_T_REVERSE_DIRECTION_TRAIN                         :{WHITE}Can't reverse direction of train...

src/newgrf_storage.h

@@ -137,7 +137,7 @@ struct TemporaryStorageArray {
 
 	StorageType storage{}; ///< Memory for the storage array
 	StorageInitType init{}; ///< Storage has been assigned, if this equals 'init_key'.
-	uint16_t init_key{1}; ///< Magic key to 'init'.
+	uint16_t init_key = 1; ///< Magic key to 'init'.
 
 	/**
 	 * Stores some value at a given position.

src/newgrf_townname.cpp

@@ -27,7 +27,7 @@ static std::vector<StringID> _grf_townname_names;
 
 GRFTownName *GetGRFTownName(uint32_t grfid)
 {
-	auto found = std::find_if(std::begin(_grf_townnames), std::end(_grf_townnames), [&grfid](const GRFTownName &t){ return t.grfid == grfid; });
+	auto found = std::find_if(std::begin(_grf_townnames), std::end(_grf_townnames), [&grfid](const GRFTownName &t) { return t.grfid == grfid; });
 	if (found != std::end(_grf_townnames)) return &*found;
 	return nullptr;
 }
@@ -44,7 +44,7 @@ GRFTownName *AddGRFTownName(uint32_t grfid)
 
 void DelGRFTownName(uint32_t grfid)
 {
-	_grf_townnames.erase(std::find_if(std::begin(_grf_townnames), std::end(_grf_townnames), [&grfid](const GRFTownName &t){ return t.grfid == grfid; }));
+	_grf_townnames.erase(std::find_if(std::begin(_grf_townnames), std::end(_grf_townnames), [&grfid](const GRFTownName &t) { return t.grfid == grfid; }));
 }
 
 static void RandomPart(StringBuilder builder, const GRFTownName *t, uint32_t seed, uint8_t id)

src/rail_gui.cpp

@@ -2759,7 +2759,7 @@ static void SetDefaultRailGui()
 		case 0: {
 			/* Use first available type */
 			std::vector<RailType>::const_iterator it = std::find_if(_sorted_railtypes.begin(), _sorted_railtypes.end(),
-					[](RailType r){ return HasRailTypeAvail(_local_company, r); });
+					[](RailType r) { return HasRailTypeAvail(_local_company, r); });
 			rt = it != _sorted_railtypes.end() ? *it : RAILTYPE_BEGIN;
 			break;
 		}

src/station_cmd.cpp

@@ -1144,7 +1144,7 @@ CommandCost CheckFlatLandRoadStop(TileArea tile_area, const RoadStopSpec *spec,
 					return ClearTile_Station(cur_tile, DC_AUTO); // Get error message.
 				}
 				/* Drive-through station in the wrong direction. */
-				if (is_drive_through && IsDriveThroughStopTile(cur_tile) && DiagDirToAxis(GetRoadStopDir(cur_tile)) != axis){
+				if (is_drive_through && IsDriveThroughStopTile(cur_tile) && DiagDirToAxis(GetRoadStopDir(cur_tile)) != axis) {
 					return_cmd_error(STR_ERROR_DRIVE_THROUGH_DIRECTION);
 				}
 				StationID st = GetStationIndex(cur_tile);

src/table/settings/misc_settings.ini

@@ -247,30 +247,6 @@ def      = 0
 min      = 0
 max      = 72
 
-[SDTG_BOOL]
-ifdef    = HAS_TRUETYPE_FONT
-name     = ""small_aa""
-var      = _fcsettings.small.aa
-def      = false
-
-[SDTG_BOOL]
-ifdef    = HAS_TRUETYPE_FONT
-name     = ""medium_aa""
-var      = _fcsettings.medium.aa
-def      = false
-
-[SDTG_BOOL]
-ifdef    = HAS_TRUETYPE_FONT
-name     = ""large_aa""
-var      = _fcsettings.large.aa
-def      = false
-
-[SDTG_BOOL]
-ifdef    = HAS_TRUETYPE_FONT
-name     = ""mono_aa""
-var      = _fcsettings.mono.aa
-def      = false
-
 [SDTG_BOOL]
 ifdef    = HAS_TRUETYPE_FONT
 name     = ""global_aa""

src/textfile_gui.h

@@ -56,10 +56,10 @@ protected:
 	void ConstructWindow();
 
 	struct Line {
-		int top{0};                  ///< Top scroll position in visual lines.
+		int top = 0;                  ///< Top scroll position in visual lines.
-		int bottom{0};               ///< Bottom scroll position in visual lines.
+		int bottom = 0;               ///< Bottom scroll position in visual lines.
-		std::string text{};          ///< Contents of the line.
+		std::string text{};           ///< Contents of the line.
-		TextColour colour{TC_WHITE}; ///< Colour to render text line in.
+		TextColour colour = TC_WHITE; ///< Colour to render text line in.
 
 		Line(int top, std::string_view text) : top(top), bottom(top + 1), text(text) {}
 		Line() {}
@@ -85,8 +85,8 @@ protected:
 	std::vector<Hyperlink> links;        ///< Clickable links in lines.
 	std::vector<Hyperlink> link_anchors; ///< Anchor names of headings that can be linked to.
 	std::vector<HistoryEntry> history;   ///< Browsing history in this window.
-	size_t history_pos{0};               ///< Position in browsing history (for forward movement).
+	size_t history_pos = 0;              ///< Position in browsing history (for forward movement).
-	bool trusted{false};                 ///< Whether the content is trusted (read: not from content like NewGRFs, etc).
+	bool trusted = false;                ///< Whether the content is trusted (read: not from content like NewGRFs, etc).
 
 	void LoadText(std::string_view buf);
 	void FindHyperlinksInMarkdown(Line &line, size_t line_index);
@@ -109,8 +109,8 @@ protected:
 	void NavigateHistory(int delta);
 
 private:
-	uint search_iterator{0};     ///< Iterator for the font check search.
+	uint search_iterator = 0;     ///< Iterator for the font check search.
-	uint max_length{0};          ///< Maximum length of unwrapped text line.
+	uint max_length = 0;          ///< Maximum length of unwrapped text line.
 
 	uint ReflowContent();
 	uint GetContentHeight();

src/tgp.cpp

@@ -446,7 +446,7 @@ static int *HeightMapMakeHistogram(Height h_min, [[maybe_unused]] Height h_max,
 	int *hist = hist_buf - h_min;
 
 	/* Count the heights and fill the histogram */
-	for (const Height &h : _height_map.h){
+	for (const Height &h : _height_map.h) {
 		assert(h >= h_min);
 		assert(h <= h_max);
 		hist[h]++;

src/town.h

@@ -382,6 +382,7 @@ inline uint16_t TownTicksToGameTicks(uint16_t ticks)
 
 
 RoadType GetTownRoadType();
+bool CheckTownRoadTypes();
 bool MayTownModifyRoad(TileIndex tile);
 
 #endif /* TOWN_H */

src/town_cmd.cpp

@@ -1088,6 +1088,45 @@ bool MayTownModifyRoad(TileIndex tile)
 	return true;
 }
 
+/**
+ * Get the calendar date of the earliest town-buildable road type.
+ * @return introduction date of earliest road type, or INT32_MAX if none available.
+ */
+static CalTime::Date GetTownRoadTypeFirstIntroductionDate()
+{
+	const RoadTypeInfo *best = nullptr;
+	for (RoadType rt = ROADTYPE_BEGIN; rt != ROADTYPE_END; rt++) {
+		if (RoadTypeIsTram(rt)) continue;
+		const RoadTypeInfo *rti = GetRoadTypeInfo(rt);
+		if (rti->label == 0) continue; // Unused road type.
+		if (!HasBit(rti->flags, ROTF_TOWN_BUILD)) continue; // Town can't build this road type.
+
+		if (best != nullptr && rti->introduction_date >= best->introduction_date) continue;
+		best = rti;
+	}
+
+	if (best == nullptr) return INT32_MAX;
+	return best->introduction_date;
+}
+
+/**
+ * Check if towns are able to build road.
+ * @return true iff the towns are currently able to build road.
+ */
+bool CheckTownRoadTypes()
+{
+	auto min_date = GetTownRoadTypeFirstIntroductionDate();
+	if (min_date <= CalTime::CurDate()) return true;
+
+	if (min_date < INT32_MAX) {
+		SetDParam(0, min_date);
+		ShowErrorMessage(STR_ERROR_NO_TOWN_ROADTYPES_AVAILABLE_YET, STR_ERROR_NO_TOWN_ROADTYPES_AVAILABLE_YET_EXPLANATION, WL_CRITICAL);
+	} else {
+		ShowErrorMessage(STR_ERROR_NO_TOWN_ROADTYPES_AVAILABLE_AT_ALL, STR_ERROR_NO_TOWN_ROADTYPES_AVAILABLE_AT_ALL_EXPLANATION, WL_CRITICAL);
+	}
+	return false;
+}
+
 /**
  * Check for parallel road inside a given distance.
  *   Assuming a road from (tile - TileOffsByDiagDir(dir)) to tile,