GRF: Allow railtype custom signal sprites for programmable pre-signals

docs/newgrf-additions.html

@@ -205,6 +205,14 @@
 	<p>This is indicated by the feature name: <font face="monospace">action0_bridge_pillar_flags</font>, version 1</p>
 	<h4>More bridges (16 instead of 13)</h4>
 	<p>This is indicated by the feature name: <font face="monospace">more_bridge_types</font>, version 1</p>
+	<h3><a href="https://newgrf-specs.tt-wiki.net/wiki/Action0/Railtypes">Action 0 - Railtypes</a></h3>
+	<h4>Enable custom signal sprites for programmable pre-signals (mappable property: railtype_enable_programmable_signals)</h4>
+	<p>This enables <a href="https://newgrf-specs.tt-wiki.net/wiki/Action3/Railtypes#Signal_sprites_.280B.29">Action 2/3 - Railtype custom signal sprites</a> for programmable pre-signals.<br />
+	Programmable pre-signals have the signal type value: 06.<br />
+	The property length is 1 byte. 0 is disabled (default). 1 is enabled.
+	</p>
+	<p>This is indicated by the feature name: <font face="monospace">action0_railtype_programmable_signals</font>, version 1</p>
+	<br />
 	<h3><a href="https://newgrf-specs.tt-wiki.net/wiki/VariationalAction2/Stations">Variational Action 2 - Stations</a></h3>
 	<h4>Track type in purchase list (42)</h4>
 	<p>This is indicated by the feature name: <font face="monospace">varaction2_station_var42</font>, version 1</p>

src/newgrf.cpp

@@ -4349,6 +4349,11 @@ static ChangeInfoResult RailTypeChangeInfo(uint id, int numinfo, int prop, const
 				for (int j = buf->ReadByte(); j != 0; j--) buf->ReadDWord();
 				break;
 
+			case A0RPI_RAILTYPE_ENABLE_PROGRAMMABLE_SIGNALS:
+				if (MappedPropertyLengthMismatch(buf, 1, mapping_entry)) break;
+				SB(rti->ctrl_flags, RTCF_PROGSIG, 1, (buf->ReadByte() != 0 ? 1 : 0));
+				break;
+
 			default:
 				ret = HandleAction0PropertyDefault(buf, prop);
 				break;
@@ -8360,6 +8365,7 @@ static const GRFFeatureInfo _grf_feature_list[] = {
 	GRFFeatureInfo("action0_bridge_prop14", 1),
 	GRFFeatureInfo("action0_bridge_pillar_flags", 1),
 	GRFFeatureInfo("action5_programmable_signals", 1),
+	GRFFeatureInfo("action0_railtype_programmable_signals", 1),
 	GRFFeatureInfo(),
 };
 
@@ -8475,6 +8481,7 @@ static const GRFPropertyMapDefinition _grf_action0_remappable_properties[] = {
 	GRFPropertyMapDefinition(GSF_STATIONS, A0RPI_STATION_DISALLOWED_BRIDGE_PILLARS, "station_disallowed_bridge_pillars"),
 	GRFPropertyMapDefinition(GSF_BRIDGES, A0RPI_BRIDGE_MENU_ICON, "bridge_menu_icon"),
 	GRFPropertyMapDefinition(GSF_BRIDGES, A0RPI_BRIDGE_PILLAR_FLAGS, "bridge_pillar_flags"),
+	GRFPropertyMapDefinition(GSF_RAILTYPES, A0RPI_RAILTYPE_ENABLE_PROGRAMMABLE_SIGNALS, "railtype_enable_programmable_signals"),
 	GRFPropertyMapDefinition(),
 };
 

src/newgrf.h

@@ -114,6 +114,7 @@ enum Action0RemapPropertyIds {
 	A0RPI_STATION_DISALLOWED_BRIDGE_PILLARS,
 	A0RPI_BRIDGE_MENU_ICON,
 	A0RPI_BRIDGE_PILLAR_FLAGS,
+	A0RPI_RAILTYPE_ENABLE_PROGRAMMABLE_SIGNALS,
 };
 
 enum GRFPropertyMapFallbackMode {

src/newgrf_railtype.cpp

@@ -127,6 +127,7 @@ SpriteID GetCustomRailSprite(const RailtypeInfo *rti, TileIndex tile, RailTypeSp
 SpriteID GetCustomSignalSprite(const RailtypeInfo *rti, TileIndex tile, SignalType type, SignalVariant var, SignalState state, bool gui)
 {
 	if (rti->group[RTSG_SIGNALS] == nullptr) return 0;
+	if (type == SIGTYPE_PROG && !HasBit(rti->ctrl_flags, RTCF_PROGSIG)) return 0;
 
 	uint32 param1 = gui ? 0x10 : 0x00;
 	uint32 param2 = (type << 16) | (var << 8) | state;

src/rail.h

@@ -41,6 +41,11 @@ enum RailTypeFlags {
 };
 DECLARE_ENUM_AS_BIT_SET(RailTypeFlags)
 
+/** Railtype control flags. */
+enum RailTypeCtrlFlags {
+	RTCF_PROGSIG           = 0,                          ///< Custom signal sprites enabled for programmable pre-signals.
+};
+
 struct SpriteGroup;
 
 /** Sprite groups for a railtype. */
@@ -208,6 +213,11 @@ public:
 	 */
 	RailTypeFlags flags;
 
+	/**
+	 * Bit mask of rail type control flags
+	 */
+	byte ctrl_flags;
+
 	/**
 	 * Cost multiplier for building this rail type
 	 */

src/rail_cmd.cpp

@@ -69,7 +69,7 @@ void ResetRailTypes()
 		{0,0,0,0,0,0,0,0,{}},
 		{0,0,0,0,0,0,0,0},
 		{0,0,0,0,0,0},
-		0, RAILTYPES_NONE, RAILTYPES_NONE, 0, 0, 0, RTFB_NONE, 0, 0, 0, 0, 0,
+		0, RAILTYPES_NONE, RAILTYPES_NONE, 0, 0, 0, RTFB_NONE, 0, 0, 0, 0, 0, 0,
 		RailTypeLabelList(), 0, 0, RAILTYPES_NONE, RAILTYPES_NONE, 0,
 		{}, {} };
 	for (; i < lengthof(_railtypes);          i++) _railtypes[i] = empty_railtype;
@@ -2489,39 +2489,38 @@ void DrawSingleSignal(TileIndex tile, const RailtypeInfo *rti, Track track, Sign
 	uint x, y;
 	GetSignalXY(tile, pos, x, y);
 
-	SpriteID sprite;
+	SpriteID sprite = GetCustomSignalSprite(rti, tile, type, variant, condition);
-	bool is_custom_sprite;
+	bool is_custom_sprite = (sprite != 0);
-	if (type == SIGTYPE_PROG) {
+	if (sprite != 0) {
+		sprite += image;
+	} else if (type == SIGTYPE_PROG) {
 		if (variant == SIG_SEMAPHORE) {
 			sprite = SPR_PROGSIGNAL_BASE + image * 2 + condition;
 		} else {
 			sprite = SPR_PROGSIGNAL_BASE + 16 + image * 2 + condition;
 		}
+
 		extern int _progsig_grf_file_index;
 		is_custom_sprite = (int) GetOriginFileSlot(sprite) != _progsig_grf_file_index;
-	} else {
-		sprite = GetCustomSignalSprite(rti, tile, type, variant, condition);
-		is_custom_sprite = (sprite != 0);
-		if (sprite != 0) {
-			sprite += image;
 	} else {
 		/* Normal electric signals are stored in a different sprite block than all other signals. */
 		sprite = (type == SIGTYPE_NORMAL && variant == SIG_ELECTRIC) ? SPR_ORIGINAL_SIGNALS_BASE : SPR_SIGNALS_BASE - 16;
 		sprite += type * 16 + variant * 64 + image * 2 + condition + (IsSignalSpritePBS(type) ? 64 : 0);
-		}
 
-		if (!is_custom_sprite) {
 		int origin_slot = GetOriginFileSlot(sprite);
 		extern int _first_user_grf_file_index;
 		extern int _opengfx_grf_file_index;
 		is_custom_sprite = origin_slot != _opengfx_grf_file_index && (origin_slot >= _first_user_grf_file_index);
 	}
-	}
 
 	if (is_custom_sprite && show_restricted && _settings_client.gui.show_restricted_signal_default) {
 		/* Use duplicate sprite block, instead of GRF-specified signals */
 		if (type == SIGTYPE_PROG) {
-			sprite += SPR_DUP_PROGSIGNAL_BASE - SPR_PROGSIGNAL_BASE;
+			if (variant == SIG_SEMAPHORE) {
+				sprite = SPR_DUP_PROGSIGNAL_BASE + image * 2 + condition;
+			} else {
+				sprite = SPR_DUP_PROGSIGNAL_BASE + 16 + image * 2 + condition;
+			}
 		} else {
 			sprite = (type == SIGTYPE_NORMAL && variant == SIG_ELECTRIC) ? SPR_DUP_ORIGINAL_SIGNALS_BASE : SPR_DUP_SIGNALS_BASE - 16;
 			sprite += type * 16 + variant * 64 + image * 2 + condition + (IsSignalSpritePBS(type) ? 64 : 0);

src/table/newgrf_debug_data.h

@@ -629,6 +629,9 @@ class NIHRailType : public NIHelper {
 					HasBit(info->flags, RTF_ALLOW_90DEG) ? 'a' : '-',
 					HasBit(info->flags, RTF_DISALLOW_90DEG) ? 'd' : '-');
 			print(buffer);
+			seprintf(buffer, lastof(buffer), "  Ctrl flags: %c",
+					HasBit(info->ctrl_flags, RTCF_PROGSIG) ? 'p' : '-');
+			print(buffer);
 		};
 
 		print("Debug Info:");

src/table/railtypes.h

@@ -77,6 +77,9 @@ static const RailtypeInfo _original_railtypes[] = {
 		/* flags */
 		RTFB_NONE,
 
+		/* control flags */
+		0,
+
 		/* cost multiplier */
 		8,
 
@@ -178,6 +181,9 @@ static const RailtypeInfo _original_railtypes[] = {
 		/* flags */
 		RTFB_CATENARY,
 
+		/* control flags */
+		0,
+
 		/* cost multiplier */
 		12,
 
@@ -275,6 +281,9 @@ static const RailtypeInfo _original_railtypes[] = {
 		/* flags */
 		RTFB_NONE,
 
+		/* control flags */
+		0,
+
 		/* cost multiplier */
 		16,
 
@@ -372,6 +381,9 @@ static const RailtypeInfo _original_railtypes[] = {
 		/* flags */
 		RTFB_NONE,
 
+		/* control flags */
+		0,
+
 		/* cost multiplier */
 		24,