Codechange: use EnumIndexArray for signal sprite and string tables

src/rail.h

@@ -147,7 +147,7 @@ public:
 		SpriteID build_depot;        ///< button for building depots
 		SpriteID build_tunnel;       ///< button for building a tunnel
 		SpriteID convert_rail;       ///< button for converting rail
-		SpriteID signals[SIGTYPE_END][2][2]; ///< signal GUI sprites (type, variant, state)
+		EnumIndexArray<EnumIndexArray<EnumIndexArray<SpriteID, SignalState, SIGNAL_STATE_END>, SignalVariant, SIG_END>, SignalType, SIGTYPE_END> signals; ///< signal GUI sprites (type, variant, state)
 	} gui_sprites;
 
 	struct {

src/rail_cmd.cpp

@@ -95,20 +95,20 @@ void ResolveRailTypeGUISprites(RailTypeInfo *rti)
 	}
 
 	/* Array of default GUI signal sprite numbers. */
-	const SpriteID _signal_lookup[2][SIGTYPE_END] = {
+	const EnumIndexArray<EnumIndexArray<SpriteID, SignalType, SIGTYPE_END>, SignalVariant, SIG_END> _signal_lookup{{{
 		{SPR_IMG_SIGNAL_ELECTRIC_NORM,  SPR_IMG_SIGNAL_ELECTRIC_ENTRY, SPR_IMG_SIGNAL_ELECTRIC_EXIT,
 		 SPR_IMG_SIGNAL_ELECTRIC_COMBO, SPR_IMG_SIGNAL_ELECTRIC_PBS,   SPR_IMG_SIGNAL_ELECTRIC_PBS_OWAY},
 
 		{SPR_IMG_SIGNAL_SEMAPHORE_NORM,  SPR_IMG_SIGNAL_SEMAPHORE_ENTRY, SPR_IMG_SIGNAL_SEMAPHORE_EXIT,
 		 SPR_IMG_SIGNAL_SEMAPHORE_COMBO, SPR_IMG_SIGNAL_SEMAPHORE_PBS,   SPR_IMG_SIGNAL_SEMAPHORE_PBS_OWAY},
-	};
+	}}};
 
-	for (SignalType type = SIGTYPE_BLOCK; type < SIGTYPE_END; type = (SignalType)(type + 1)) {
-		for (SignalVariant var = SIG_ELECTRIC; var <= SIG_SEMAPHORE; var = (SignalVariant)(var + 1)) {
-			SpriteID red   = GetCustomSignalSprite(rti, INVALID_TILE, type, var, SIGNAL_STATE_RED, true);
+	for (SignalType type = SIGTYPE_BLOCK; type < SIGTYPE_END; type = static_cast<SignalType>(to_underlying(type) + 1)) {
+		for (SignalVariant var : {SIG_ELECTRIC, SIG_SEMAPHORE}) {
+			SpriteID red = GetCustomSignalSprite(rti, INVALID_TILE, type, var, SIGNAL_STATE_RED, true);
 			SpriteID green = GetCustomSignalSprite(rti, INVALID_TILE, type, var, SIGNAL_STATE_GREEN, true);
-			rti->gui_sprites.signals[type][var][0] = (red != 0)   ? red + SIGNAL_TO_SOUTH   : _signal_lookup[var][type];
-			rti->gui_sprites.signals[type][var][1] = (green != 0) ? green + SIGNAL_TO_SOUTH : _signal_lookup[var][type] + 1;
+			rti->gui_sprites.signals[type][var][SIGNAL_STATE_RED] = (red != 0) ? red + SIGNAL_TO_SOUTH : _signal_lookup[var][type];
+			rti->gui_sprites.signals[type][var][SIGNAL_STATE_GREEN] = (green != 0) ? green + SIGNAL_TO_SOUTH : _signal_lookup[var][type] + 1;
 		}
 	}
 }
@@ -2838,7 +2838,7 @@ static void GetTileDesc_Rail(TileIndex tile, TileDesc &td)
 			break;
 
 		case RailTileType::Signals: {
-			static const StringID signal_type[6][6] = {
+			static constexpr EnumIndexArray<EnumIndexArray<StringID, SignalType, SIGTYPE_END>, SignalType, SIGTYPE_END> signal_type{{{
 				{
 					STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SIGNALS,
 					STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
@@ -2886,8 +2886,8 @@ static void GetTileDesc_Rail(TileIndex tile, TileDesc &td)
 					STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS,
 					STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS,
 					STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRYSIGNALS
-				}
-			};
+				},
+			}}};
 
 			SignalType primary_signal;
 			SignalType secondary_signal;

src/rail_gui.cpp

@@ -1554,11 +1554,11 @@ public:
 		this->sig_sprite_size.height = 0;
 		this->sig_sprite_bottom_offset = 0;
 		const RailTypeInfo *rti = GetRailTypeInfo(_cur_railtype);
-		for (uint type = SIGTYPE_BLOCK; type < SIGTYPE_END; type++) {
-			for (uint variant = SIG_ELECTRIC; variant <= SIG_SEMAPHORE; variant++) {
-				for (uint lowered = 0; lowered < 2; lowered++) {
+		for (SignalType type = SIGTYPE_BLOCK; type < SIGTYPE_END; type = static_cast<SignalType>(to_underlying(type) + 1)) {
+			for (SignalVariant variant : {SIG_ELECTRIC, SIG_SEMAPHORE}) {
+				for (SignalState state : {SIGNAL_STATE_RED, SIGNAL_STATE_GREEN}) {
 					Point offset;
-					Dimension sprite_size = GetSpriteSize(rti->gui_sprites.signals[type][variant][lowered], &offset);
+					Dimension sprite_size = GetSpriteSize(rti->gui_sprites.signals[type][variant][state], &offset);
 					this->sig_sprite_bottom_offset = std::max<int>(this->sig_sprite_bottom_offset, sprite_size.height);
 					this->sig_sprite_size.width = std::max<int>(this->sig_sprite_size.width, sprite_size.width - offset.x);
 					this->sig_sprite_size.height = std::max<int>(this->sig_sprite_size.height, sprite_size.height - offset.y);
@@ -1593,9 +1593,9 @@ public:
 	{
 		if (IsInsideMM(widget, WID_BS_SEMAPHORE_NORM, WID_BS_ELECTRIC_PBS_OWAY + 1)) {
 			/* Extract signal from widget number. */
-			int type = (widget - WID_BS_SEMAPHORE_NORM) % SIGTYPE_END;
-			int var = SIG_SEMAPHORE - (widget - WID_BS_SEMAPHORE_NORM) / SIGTYPE_END; // SignalVariant order is reversed compared to the widgets.
-			SpriteID sprite = GetRailTypeInfo(_cur_railtype)->gui_sprites.signals[type][var][this->IsWidgetLowered(widget)];
+			SignalType type = static_cast<SignalType>((widget - WID_BS_SEMAPHORE_NORM) % SIGTYPE_END);
+			SignalVariant var = static_cast<SignalVariant>(SIG_SEMAPHORE - (widget - WID_BS_SEMAPHORE_NORM) / SIGTYPE_END); // SignalVariant order is reversed compared to the widgets.
+			SpriteID sprite = GetRailTypeInfo(_cur_railtype)->gui_sprites.signals[type][var][static_cast<SignalState>(this->IsWidgetLowered(widget))];
 
 			this->DrawSignalSprite(r, sprite);
 		}

src/signal_type.h

@@ -16,6 +16,7 @@
 enum SignalVariant : uint8_t {
 	SIG_ELECTRIC  = 0, ///< Light signal
 	SIG_SEMAPHORE = 1, ///< Old-fashioned semaphore signal
+	SIG_END, ///< End marker.
 };
 
 
@@ -28,7 +29,7 @@ enum SignalType : uint8_t {
 	SIGTYPE_PBS        = 4, ///< normal pbs signal
 	SIGTYPE_PBS_ONEWAY = 5, ///< no-entry signal
 
-	SIGTYPE_END,
+	SIGTYPE_END, /// End marker.
 	SIGTYPE_LAST       = SIGTYPE_PBS_ONEWAY,
 	SIGTYPE_LAST_NOPBS = SIGTYPE_COMBO,
 };
@@ -42,6 +43,7 @@ DECLARE_ENUM_AS_ADDABLE(SignalType)
 enum SignalState : uint8_t {
 	SIGNAL_STATE_RED   = 0, ///< The signal is red
 	SIGNAL_STATE_GREEN = 1, ///< The signal is green
+	SIGNAL_STATE_END, ///< End marker.
 };
 
 #endif /* SIGNAL_TYPE_H */