Change: Provide road and rail overlay sprites for bridge decks. (#14557)

This allows bridges designed primarily with NewGRF railtypes and roadtypes to be at least somewhat compatible with built-in rail and road.

media/baseset/openttd.grf.hash

@@ -1 +1 @@
-eb8390a0569e66ec417c64ad254f9d05
+b779126d7cd1567eb09a0a7871f70a71

media/baseset/openttd/CMakeLists.txt

@@ -10,6 +10,7 @@ if(GRFCODEC_FOUND)
                          ${CMAKE_CURRENT_SOURCE_DIR}/airport_preview.nfo
                          ${CMAKE_CURRENT_SOURCE_DIR}/aqueduct.nfo
                          ${CMAKE_CURRENT_SOURCE_DIR}/autorail.nfo
+                         ${CMAKE_CURRENT_SOURCE_DIR}/bridge_decks.nfo
                          ${CMAKE_CURRENT_SOURCE_DIR}/canals.nfo
                          ${CMAKE_CURRENT_SOURCE_DIR}/chars.nfo
                          ${CMAKE_CURRENT_SOURCE_DIR}/elrails.nfo
@@ -31,6 +32,7 @@ if(GRFCODEC_FOUND)
                          ${CMAKE_CURRENT_SOURCE_DIR}/airport_preview.png
                          ${CMAKE_CURRENT_SOURCE_DIR}/aqueduct.png
                          ${CMAKE_CURRENT_SOURCE_DIR}/autorail.png
+                         ${CMAKE_CURRENT_SOURCE_DIR}/bridge_decks.png
                          ${CMAKE_CURRENT_SOURCE_DIR}/canals.png
                          ${CMAKE_CURRENT_SOURCE_DIR}/canal_locks.png
                          ${CMAKE_CURRENT_SOURCE_DIR}/chars.png

media/baseset/openttd/bridge_decks.nfo

@@ -0,0 +1,36 @@
+// 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/>.
+//
+   -1 * 0	 0C "Bridge decks"
+   -1 * 3	 05 1B 18
+
+   -1 sprites/bridge_decks.png 8bpp   96  16  64  31 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp   16  16  64  31 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  176  16  64  39 -31   -8 normal
+   -1 sprites/bridge_decks.png 8bpp  256  16  64  23 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  336  16  64  23 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  416  16  64  39 -31   -8 normal
+
+   -1 sprites/bridge_decks.png 8bpp   96  71  64  31 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp   16  71  64  31 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  176  71  64  39 -31   -8 normal
+   -1 sprites/bridge_decks.png 8bpp  256  71  64  23 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  336  71  64  23 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  416  71  64  39 -31   -8 normal
+
+   -1 sprites/bridge_decks.png 8bpp   96 126  64  31 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp   16 126  64  31 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  176 126  64  39 -31   -8 normal
+   -1 sprites/bridge_decks.png 8bpp  256 126  64  23 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  336 126  64  23 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  416 126  64  39 -31   -8 normal
+
+// X and Y axis are swapped for road surface.
+   -1 sprites/bridge_decks.png 8bpp   16 181  64  31 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp   96 181  64  31 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  176 181  64  39 -31   -8 normal
+   -1 sprites/bridge_decks.png 8bpp  256 181  64  23 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  336 181  64  23 -31    0 normal
+   -1 sprites/bridge_decks.png 8bpp  416 181  64  39 -31   -8 normal

media/baseset/openttd/openttd.nfo

@@ -100,3 +100,4 @@
 #include "palette.nfo"
 #include "road_waypoints.nfo"
 #include "overlay_rocks.nfo"
+#include "bridge_decks.nfo"

src/newgrf/newgrf_act5.cpp

@@ -78,6 +78,7 @@ static constexpr auto _action5_types = std::to_array<Action5Type>({
 	/* 0x18 */ { A5BLOCK_ALLOW_OFFSET, SPR_PALETTE_BASE,             1, PALETTE_SPRITE_COUNT,                        "Palette"                  },
 	/* 0x19 */ { A5BLOCK_ALLOW_OFFSET, SPR_ROAD_WAYPOINTS_BASE,      1, ROAD_WAYPOINTS_SPRITE_COUNT,                 "Road waypoints"           },
 	/* 0x1A */ { A5BLOCK_ALLOW_OFFSET, SPR_OVERLAY_ROCKS_BASE,       1, OVERLAY_ROCKS_SPRITE_COUNT,                  "Overlay rocks"            },
+	/* 0x1B */ { A5BLOCK_ALLOW_OFFSET, SPR_BRIDGE_DECKS_BASE,        1, BRIDGE_DECKS_SPRITE_COUNT,                   "Bridge decks"             },
 });
 
 /**

src/rail.h

@@ -131,6 +131,7 @@ public:
 		SpriteID single_sloped;///< single piece of rail for slopes
 		SpriteID crossing;     ///< level crossing, rail in X direction
 		SpriteID tunnel;       ///< tunnel sprites base
+		SpriteID bridge_deck;  ///< bridge deck sprites base
 	} base_sprites;
 
 	/**

src/table/railtypes.h

@@ -25,7 +25,7 @@ static const RailTypeInfo _original_railtypes[] = {
 			SPR_RAIL_SINGLE_NORTH, SPR_RAIL_SINGLE_SOUTH, SPR_RAIL_SINGLE_EAST, SPR_RAIL_SINGLE_WEST,
 			SPR_TRACKS_FOR_SLOPES_RAIL_BASE,
 			SPR_CROSSING_OFF_X_RAIL,
-			SPR_TUNNEL_ENTRY_REAR_RAIL
+			SPR_TUNNEL_ENTRY_REAR_RAIL, SPR_BRIDGE_DECKS_RAIL,
 		},
 
 		/* GUI sprites */
@@ -123,7 +123,7 @@ static const RailTypeInfo _original_railtypes[] = {
 			SPR_RAIL_SINGLE_NORTH, SPR_RAIL_SINGLE_SOUTH, SPR_RAIL_SINGLE_EAST, SPR_RAIL_SINGLE_WEST,
 			SPR_TRACKS_FOR_SLOPES_RAIL_BASE,
 			SPR_CROSSING_OFF_X_RAIL,
-			SPR_TUNNEL_ENTRY_REAR_RAIL
+			SPR_TUNNEL_ENTRY_REAR_RAIL, SPR_BRIDGE_DECKS_RAIL,
 		},
 
 		/* GUI sprites */
@@ -225,7 +225,7 @@ static const RailTypeInfo _original_railtypes[] = {
 			SPR_MONO_SINGLE_NORTH, SPR_MONO_SINGLE_SOUTH, SPR_MONO_SINGLE_EAST, SPR_MONO_SINGLE_WEST,
 			SPR_TRACKS_FOR_SLOPES_MONO_BASE,
 			SPR_CROSSING_OFF_X_MONO,
-			SPR_TUNNEL_ENTRY_REAR_MONO
+			SPR_TUNNEL_ENTRY_REAR_MONO, SPR_BRIDGE_DECKS_MONO,
 		},
 
 		/* GUI sprites */
@@ -323,7 +323,7 @@ static const RailTypeInfo _original_railtypes[] = {
 			SPR_MGLV_SINGLE_NORTH, SPR_MGLV_SINGLE_SOUTH, SPR_MGLV_SINGLE_EAST, SPR_MGLV_SINGLE_WEST,
 			SPR_TRACKS_FOR_SLOPES_MAGLEV_BASE,
 			SPR_CROSSING_OFF_X_MAGLEV,
-			SPR_TUNNEL_ENTRY_REAR_MAGLEV
+			SPR_TUNNEL_ENTRY_REAR_MAGLEV, SPR_BRIDGE_DECKS_MGLV,
 		},
 
 		/* GUI sprites */

src/table/sprites.h

@@ -321,8 +321,16 @@ static const uint16_t ROAD_WAYPOINTS_SPRITE_COUNT = 4;
 static constexpr SpriteID SPR_OVERLAY_ROCKS_BASE = SPR_ROAD_WAYPOINTS_BASE + ROAD_WAYPOINTS_SPRITE_COUNT;
 static constexpr uint16_t OVERLAY_ROCKS_SPRITE_COUNT = 19 * 5; /* Rock overlays: plain, snow 1, snow 2, snow 3 and full snow. */
 
+/** Bridge deck sprites. */
+static constexpr SpriteID SPR_BRIDGE_DECKS_BASE = SPR_OVERLAY_ROCKS_BASE + OVERLAY_ROCKS_SPRITE_COUNT;
+static constexpr uint16_t BRIDGE_DECKS_SPRITE_COUNT = 6 * 4; /* Bridge deck sprites: 6 directions * (3 track types + 1 road type). */
+static const SpriteID SPR_BRIDGE_DECKS_RAIL = SPR_BRIDGE_DECKS_BASE + 0;
+static const SpriteID SPR_BRIDGE_DECKS_MONO = SPR_BRIDGE_DECKS_BASE + 6;
+static const SpriteID SPR_BRIDGE_DECKS_MGLV = SPR_BRIDGE_DECKS_BASE + 12;
+static const SpriteID SPR_BRIDGE_DECKS_ROAD = SPR_BRIDGE_DECKS_BASE + 18;
+
 /* From where can we start putting NewGRFs? */
-static const SpriteID SPR_NEWGRFS_BASE = SPR_OVERLAY_ROCKS_BASE + OVERLAY_ROCKS_SPRITE_COUNT;
+static const SpriteID SPR_NEWGRFS_BASE = SPR_BRIDGE_DECKS_BASE + BRIDGE_DECKS_SPRITE_COUNT;
 
 /* Manager face sprites */
 static const SpriteID SPR_GRADIENT = 874; // background gradient behind manager face

src/tunnelbridge_cmd.cpp

@@ -135,6 +135,19 @@ bool HasBridgeFlatRamp(Slope tileh, Axis axis)
 	return (tileh != SLOPE_FLAT);
 }
 
+/**
+ * Test if bridge piece uses a custom sprite table.
+ * @param bridge_type Bridge type.
+ * @param piece Bridge piece.
+ * @return True iff a custom sprite table is used for the bridge piece.
+ */
+static bool BridgeHasCustomSpriteTable(BridgeType bridge_type, BridgePieces piece)
+{
+	assert(piece < NUM_BRIDGE_PIECES);
+	const BridgeSpec *bridge = GetBridgeSpec(bridge_type);
+	return piece < bridge->sprite_table.size() && !bridge->sprite_table[piece].empty();
+}
+
 /**
  * Get the sprite table for a rail/road bridge piece.
  * @param bridge_type Bridge type.
@@ -1158,8 +1171,9 @@ static void GetBridgeRoadCatenary(const RoadTypeInfo *rti, TileIndex head_tile,
  * @param z            the z of the bridge
  * @param offset       sprite offset identifying flat to sloped bridge tiles
  * @param head         are we drawing bridge head?
+ * @param is_custom_layout Set if the bridge uses a custom sprite layout.
  */
-static void DrawBridgeRoadBits(TileIndex head_tile, int x, int y, int z, int offset, bool head)
+static void DrawBridgeRoadBits(TileIndex head_tile, int x, int y, int z, int offset, bool head, bool is_custom_layout)
 {
 	RoadType road_rt = GetRoadTypeRoad(head_tile);
 	RoadType tram_rt = GetRoadTypeTram(head_tile);
@@ -1178,6 +1192,9 @@ static void DrawBridgeRoadBits(TileIndex head_tile, int x, int y, int z, int off
 		if (road_rti != nullptr) {
 			if (road_rti->UsesOverlay()) {
 				seq_back[0] = GetCustomRoadSprite(road_rti, head_tile, ROTSG_BRIDGE, head ? TCX_NORMAL : TCX_ON_BRIDGE) + offset;
+			} else if (is_custom_layout) {
+				/* For custom layouts draw a custom bridge deck. */
+				seq_back[0] = SPR_BRIDGE_DECKS_ROAD + offset;
 			}
 		} else if (tram_rti != nullptr) {
 			if (tram_rti->UsesOverlay()) {
@@ -1428,13 +1445,16 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 		DrawBridgeMiddle(ti, BridgePillarFlag::EdgeNE + tunnelbridge_direction);
 	} else { // IsBridge(ti->tile)
 		DrawFoundation(ti, GetBridgeFoundation(ti->tileh, DiagDirToAxis(tunnelbridge_direction)));
+		bool is_custom_layout; // Set if rail/road bridge uses a custom layout.
 
 		uint base_offset = GetBridgeRampDirectionBaseOffset(tunnelbridge_direction);
 		std::span<const PalSpriteID> psid;
 		if (transport_type != TRANSPORT_WATER) {
+			BridgeType bridge_type = GetBridgeType(ti->tile);
 			if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
 			base_offset += GetBridgeSpriteTableBaseOffset(transport_type, ti->tile);
-			psid = GetBridgeSpriteTable(GetBridgeType(ti->tile), BRIDGE_PIECE_HEAD);
+			psid = GetBridgeSpriteTable(bridge_type, BRIDGE_PIECE_HEAD);
+			is_custom_layout = BridgeHasCustomSpriteTable(bridge_type, BRIDGE_PIECE_HEAD);
 		} else {
 			psid = _aqueduct_sprite_table_heads;
 		}
@@ -1473,23 +1493,18 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 			}
 
 			/* DrawBridgeRoadBits() calls EndSpriteCombine() and StartSpriteCombine() */
-			DrawBridgeRoadBits(ti->tile, ti->x, ti->y, z, offset, true);
+			DrawBridgeRoadBits(ti->tile, ti->x, ti->y, z, offset, true, is_custom_layout);
 
 			EndSpriteCombine();
 		} else if (transport_type == TRANSPORT_RAIL) {
 			const RailTypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
-			if (rti->UsesOverlay()) {
+			SpriteID surface = rti->UsesOverlay() ? GetCustomRailSprite(rti, ti->tile, RTSG_BRIDGE) : rti->base_sprites.bridge_deck;
-				SpriteID surface = GetCustomRailSprite(rti, ti->tile, RTSG_BRIDGE);
+			if (surface != 0) {
-				if (surface != 0) {
+				if (HasBridgeFlatRamp(ti->tileh, DiagDirToAxis(tunnelbridge_direction))) {
-					if (HasBridgeFlatRamp(ti->tileh, DiagDirToAxis(tunnelbridge_direction))) {
+					AddSortableSpriteToDraw(surface + ((DiagDirToAxis(tunnelbridge_direction) == AXIS_X) ? RTBO_X : RTBO_Y), PAL_NONE, *ti, {{0, 0, TILE_HEIGHT}, {TILE_SIZE, TILE_SIZE, 0}, {}});
-						AddSortableSpriteToDraw(surface + ((DiagDirToAxis(tunnelbridge_direction) == AXIS_X) ? RTBO_X : RTBO_Y), PAL_NONE, *ti, {{0, 0, TILE_HEIGHT}, {TILE_SIZE, TILE_SIZE, 0}, {}});
+				} else {
-					} else {
+					AddSortableSpriteToDraw(surface + RTBO_SLOPE + tunnelbridge_direction, PAL_NONE, *ti, {{}, {TILE_SIZE, TILE_SIZE, TILE_HEIGHT}, {}});
-						AddSortableSpriteToDraw(surface + RTBO_SLOPE + tunnelbridge_direction, PAL_NONE, *ti, {{}, {TILE_SIZE, TILE_SIZE, TILE_HEIGHT}, {}});
-					}
 				}
-				/* Don't fallback to non-overlay sprite -- the spec states that
-				 * if an overlay is present then the bridge surface must be
-				 * present. */
 			}
 
 			/* PBS debugging, draw reserved tracks darker */
@@ -1614,16 +1629,19 @@ void DrawBridgeMiddle(const TileInfo *ti, BridgePillarFlags blocked_pillars)
 	TransportType transport_type = GetTunnelBridgeTransportType(rampsouth);
 	Axis axis = GetBridgeAxis(ti->tile);
 	BridgePillarFlags pillars;
+	bool is_custom_layout; // Set if rail/road bridge uses a custom layout.
 
 	uint base_offset = GetBridgeMiddleAxisBaseOffset(axis);
 	std::span<const PalSpriteID> psid;
 	bool drawfarpillar;
 	if (transport_type != TRANSPORT_WATER) {
 		BridgeType bridge_type = GetBridgeType(rampsouth);
+		BridgePieces bridge_piece = CalcBridgePiece(GetTunnelBridgeLength(ti->tile, rampnorth) + 1, GetTunnelBridgeLength(ti->tile, rampsouth) + 1);
 		drawfarpillar = !HasBit(GetBridgeSpec(bridge_type)->flags, 0);
 		base_offset += GetBridgeSpriteTableBaseOffset(transport_type, rampsouth);
-		psid = GetBridgeSpriteTable(bridge_type, CalcBridgePiece(GetTunnelBridgeLength(ti->tile, rampnorth) + 1, GetTunnelBridgeLength(ti->tile, rampsouth) + 1));
+		psid = GetBridgeSpriteTable(bridge_type, bridge_piece);
 		pillars = GetBridgeTilePillarFlags(ti->tile, rampnorth, rampsouth, bridge_type, transport_type);
+		is_custom_layout = BridgeHasCustomSpriteTable(bridge_type, bridge_piece);
 	} else {
 		drawfarpillar = true;
 		psid = _aqueduct_sprite_table_middle;
@@ -1653,11 +1671,11 @@ void DrawBridgeMiddle(const TileInfo *ti, BridgePillarFlags blocked_pillars)
 
 	if (transport_type == TRANSPORT_ROAD) {
 		/* DrawBridgeRoadBits() calls EndSpriteCombine() and StartSpriteCombine() */
-		DrawBridgeRoadBits(rampsouth, x, y, bridge_z, axis ^ 1, false);
+		DrawBridgeRoadBits(rampsouth, x, y, bridge_z, axis ^ 1, false, is_custom_layout);
 	} else if (transport_type == TRANSPORT_RAIL) {
 		const RailTypeInfo *rti = GetRailTypeInfo(GetRailType(rampsouth));
-		if (rti->UsesOverlay() && !IsInvisibilitySet(TO_BRIDGES)) {
+		if (!IsInvisibilitySet(TO_BRIDGES)) {
-			SpriteID surface = GetCustomRailSprite(rti, rampsouth, RTSG_BRIDGE, TCX_ON_BRIDGE);
+			SpriteID surface = rti->UsesOverlay() ? GetCustomRailSprite(rti, rampsouth, RTSG_BRIDGE, TCX_ON_BRIDGE) : rti->base_sprites.bridge_deck;
 			if (surface != 0) {
 				AddSortableSpriteToDraw(surface + axis, PAL_NONE, x, y, bridge_z, {{}, {TILE_SIZE, TILE_SIZE, 0}, {}}, IsTransparencySet(TO_BRIDGES));
 			}