(svn r23952) -Feature: [NewGRF] Customisable tunnel portals for rail types (sprites by Snail).

4 files changed, 21 insertions, 4 deletions

diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index cce56ccaa..feccc2363 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -5458,6 +5458,7 @@ static const Action5Type _action5_types[] = {
 	/* 0x14 */ { A5BLOCK_ALLOW_OFFSET, SPR_FLAGS_BASE,               1, FLAGS_SPRITE_COUNT,                          "Flag graphics"            },
 	/* 0x15 */ { A5BLOCK_ALLOW_OFFSET, SPR_OPENTTD_BASE,             1, OPENTTD_SPRITE_COUNT,                        "OpenTTD GUI graphics"     },
 	/* 0x16 */ { A5BLOCK_ALLOW_OFFSET, SPR_AIRPORT_PREVIEW_BASE,     1, SPR_AIRPORT_PREVIEW_COUNT,                   "Airport preview graphics" },
+	/* 0x17 */ { A5BLOCK_ALLOW_OFFSET, SPR_RAILTYPE_TUNNEL_BASE,     1, RAILTYPE_TUNNEL_BASE_COUNT,                  "Railtype tunnel base"     },
 };
 
 /* Action 0x05 */
diff --git a/src/rail.h b/src/rail.h
index 03bc69364..eb0b46c4c 100644
--- a/src/rail.h
+++ b/src/rail.h
@@ -46,6 +46,7 @@ enum RailTypeSpriteGroup {
 	RTSG_CROSSING,    ///< Level crossing overlay images
 	RTSG_DEPOT,       ///< Depot images
 	RTSG_FENCES,      ///< Fence images
+	RTSG_TUNNEL_PORTAL, ///< Tunnel portal overlay
 	RTSG_END,
 };
 
diff --git a/src/table/sprites.h b/src/table/sprites.h
index 4953070b3..8320e2c52 100644
--- a/src/table/sprites.h
+++ b/src/table/sprites.h
@@ -270,8 +270,12 @@ static const uint16 ONEWAY_SPRITE_COUNT = 6;
 static const SpriteID SPR_FLAGS_BASE = SPR_ONEWAY_BASE + ONEWAY_SPRITE_COUNT;
 static const uint16 FLAGS_SPRITE_COUNT = 36;
 
+/** Tunnel sprites with grass only for custom railtype tunnel. */
+static const SpriteID SPR_RAILTYPE_TUNNEL_BASE = SPR_FLAGS_BASE + FLAGS_SPRITE_COUNT;
+static const uint16 RAILTYPE_TUNNEL_BASE_COUNT = 16;
+
 /* Not really a sprite, but an empty bounding box. Used to construct bounding boxes that help sorting the sprites, but do not have a sprite associated. */
-static const SpriteID SPR_EMPTY_BOUNDING_BOX = SPR_FLAGS_BASE + FLAGS_SPRITE_COUNT;
+static const SpriteID SPR_EMPTY_BOUNDING_BOX = SPR_RAILTYPE_TUNNEL_BASE + RAILTYPE_TUNNEL_BASE_COUNT;
 static const uint16 EMPTY_BOUNDING_BOX_SPRITE_COUNT = 1;
 
 /* From where can we start putting NewGRFs? */
diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
index 797aa4725..945563fb5 100644
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -1115,13 +1115,20 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 		bool catenary = false;
 
 		SpriteID image;
+		SpriteID railtype_overlay = 0;
 		if (transport_type == TRANSPORT_RAIL) {
-			image = GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.tunnel;
+			const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
+			image = rti->base_sprites.tunnel;
+			if (rti->UsesOverlay()) {
+				/* Check if the railtype has custom tunnel portals. */
+				railtype_overlay = GetCustomRailSprite(rti, ti->tile, RTSG_TUNNEL_PORTAL);
+				if (railtype_overlay != 0) image = SPR_RAILTYPE_TUNNEL_BASE; // Draw blank grass tunnel base.
+			}
 		} else {
 			image = SPR_TUNNEL_ENTRY_REAR_ROAD;
 		}
 
-		if (HasTunnelBridgeSnowOrDesert(ti->tile)) image += 32;
+		if (HasTunnelBridgeSnowOrDesert(ti->tile)) image += railtype_overlay != 0 ? 8 : 32;
 
 		image += tunnelbridge_direction * 2;
 		DrawGroundSprite(image, PAL_NONE);
@@ -1164,9 +1171,13 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 			}
 		}
 
+		if (railtype_overlay != 0 && !catenary) StartSpriteCombine();
+
 		AddSortableSpriteToDraw(image + 1, PAL_NONE, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, BB_data[0], BB_data[1], TILE_HEIGHT, ti->z, false, BB_data[2], BB_data[3], BB_Z_SEPARATOR);
+		/* Draw railtype tunnel portal overlay if defined. */
+		if (railtype_overlay != 0) AddSortableSpriteToDraw(railtype_overlay + tunnelbridge_direction, PAL_NONE, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, BB_data[0], BB_data[1], TILE_HEIGHT, ti->z, false, BB_data[2], BB_data[3], BB_Z_SEPARATOR);
 
-		if (catenary) EndSpriteCombine();
+		if (catenary || railtype_overlay != 0) EndSpriteCombine();
 
 		/* Add helper BB for sprite sorting that separates the tunnel from things beside of it. */
 		AddSortableSpriteToDraw(SPR_EMPTY_BOUNDING_BOX, PAL_NONE, ti->x,              ti->y,              BB_data[6], BB_data[7], TILE_HEIGHT, ti->z);