# HG changeset patch
# User celestar
# Date 1167393808 0
# Node ID 04068f82afaa674cbb30514faf66104580413eb6
# Parent  3e0dd1f014ca4f8005de57fe6a8c11518641ec37
(svn r7612) [cbh] Copied tunnelbridge_cmd.c to tunnel_cmd.c and bridge_cmd.c. Removed tunnelbridge_cmd.c

diff -r 3e0dd1f014ca -r 04068f82afaa Makefile
--- a/Makefile	Fri Dec 29 11:03:39 2006 +0000
+++ b/Makefile	Fri Dec 29 12:03:28 2006 +0000
@@ -796,7 +796,7 @@
 SRCS += train_gui.c
 SRCS += tree_cmd.c
 SRCS += tunnel_map.c
-SRCS += tunnelbridge_cmd.c
+SRCS += tunnel_cmd.c
 SRCS += unmovable_cmd.c
 SRCS += vehicle.c
 SRCS += vehicle_gui.c
diff -r 3e0dd1f014ca -r 04068f82afaa bridge_cmd.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bridge_cmd.c	Fri Dec 29 12:03:28 2006 +0000
@@ -0,0 +1,1415 @@
+/* $Id$ */
+
+/** @file tunnelbridge_cmd.c
+ * This file deals with tunnels and bridges (non-gui stuff)
+ * @todo seperate this file into two
+ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "bridge_map.h"
+#include "rail_map.h"
+#include "road_map.h"
+#include "table/sprites.h"
+#include "table/strings.h"
+#include "functions.h"
+#include "map.h"
+#include "tile.h"
+#include "tunnel_map.h"
+#include "unmovable_map.h"
+#include "vehicle.h"
+#include "viewport.h"
+#include "command.h"
+#include "player.h"
+#include "town.h"
+#include "sound.h"
+#include "variables.h"
+#include "bridge.h"
+#include "train.h"
+#include "water_map.h"
+#include "yapf/yapf.h"
+#include "date.h"
+#include "newgrf_sound.h"
+
+#include "table/bridge_land.h"
+
+const Bridge orig_bridge[] = {
+/*
+	     year of availablity
+	     |  minimum length
+	     |  |   maximum length
+	     |  |   |    price
+	     |  |   |    |    maximum speed
+	     |  |   |    |    |  sprite to use in GUI                string with description
+	     |  |   |    |    |  |                                   |                            */
+	{    0, 0, 16,  80,  32, 0xA24                             , STR_5012_WOODEN             , NULL, 0 },
+	{    0, 0,  2, 112,  48, 0xA26 | PALETTE_TO_STRUCT_RED     , STR_5013_CONCRETE           , NULL, 0 },
+	{ 1930, 0,  5, 144,  64, 0xA25                             , STR_500F_GIRDER_STEEL       , NULL, 0 },
+	{    0, 2, 10, 168,  80, 0xA22 | PALETTE_TO_STRUCT_CONCRETE, STR_5011_SUSPENSION_CONCRETE, NULL, 0 },
+	{ 1930, 3, 16, 185,  96, 0xA22                             , STR_500E_SUSPENSION_STEEL   , NULL, 0 },
+	{ 1930, 3, 16, 192, 112, 0xA22 | PALETTE_TO_STRUCT_YELLOW  , STR_500E_SUSPENSION_STEEL   , NULL, 0 },
+	{ 1930, 3,  7, 224, 160, 0xA23                             , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
+	{ 1930, 3,  8, 232, 208, 0xA23 | PALETTE_TO_STRUCT_BROWN   , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
+	{ 1930, 3,  9, 248, 240, 0xA23 | PALETTE_TO_STRUCT_RED     , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
+	{ 1930, 0,  2, 240, 256, 0xA27                             , STR_500F_GIRDER_STEEL       , NULL, 0 },
+	{ 1995, 2, 16, 255, 320, 0xA28                             , STR_5014_TUBULAR_STEEL      , NULL, 0 },
+	{ 2005, 2, 32, 380, 512, 0xA28 | PALETTE_TO_STRUCT_YELLOW  , STR_5014_TUBULAR_STEEL      , NULL, 0 },
+	{ 2010, 2, 32, 510, 608, 0xA28 | PALETTE_TO_STRUCT_GREY    , STR_BRIDGE_TUBULAR_SILICON  , NULL, 0 }
+};
+
+Bridge _bridge[MAX_BRIDGES];
+
+
+// calculate the price factor for building a long bridge.
+// basically the cost delta is 1,1, 1, 2,2, 3,3,3, 4,4,4,4, 5,5,5,5,5, 6,6,6,6,6,6,  7,7,7,7,7,7,7,  8,8,8,8,8,8,8,8,
+int CalcBridgeLenCostFactor(int x)
+{
+	int n;
+	int r;
+
+	if (x < 2) return x;
+	x -= 2;
+	for (n = 0, r = 2;; n++) {
+		if (x <= n) return r + x * n;
+		r += n * n;
+		x -= n;
+	}
+}
+
+#define M(x) (1 << (x))
+enum {
+	// foundation, whole tile is leveled up --> 3 corners raised
+	BRIDGE_FULL_LEVELED_FOUNDATION = M(SLOPE_WSE) | M(SLOPE_NWS) | M(SLOPE_ENW) | M(SLOPE_SEN),
+	// foundation, tile is partly leveled up --> 1 corner raised
+	BRIDGE_PARTLY_LEVELED_FOUNDATION = M(SLOPE_W) | M(SLOPE_S) | M(SLOPE_E) | M(SLOPE_N),
+	// no foundations (X,Y direction)
+	BRIDGE_NO_FOUNDATION = M(SLOPE_FLAT) | M(SLOPE_SW) | M(SLOPE_SE) | M(SLOPE_NW) | M(SLOPE_NE),
+	BRIDGE_HORZ_RAMP = (BRIDGE_PARTLY_LEVELED_FOUNDATION | BRIDGE_NO_FOUNDATION) & ~M(SLOPE_FLAT)
+};
+#undef M
+
+static inline const PalSpriteID *GetBridgeSpriteTable(int index, byte table)
+{
+	const Bridge *bridge = &_bridge[index];
+	assert(table < 7);
+	if (bridge->sprite_table == NULL || bridge->sprite_table[table] == NULL) {
+		return _bridge_sprite_table[index][table];
+	} else {
+		return bridge->sprite_table[table];
+	}
+}
+
+static inline byte GetBridgeFlags(int index) { return _bridge[index].flags;}
+
+
+/** Check the slope at the bridge ramps in three easy steps:
+ * - valid slopes without foundation
+ * - valid slopes with foundation
+ * - rest is invalid
+ */
+#define M(x) (1 << (x))
+static int32 CheckBridgeSlopeNorth(Axis axis, Slope tileh)
+{
+	uint32 valid;
+
+	valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_NE) : M(SLOPE_NW));
+	if (HASBIT(valid, tileh)) return 0;
+
+	valid =
+		BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_N) | M(SLOPE_STEEP_N) |
+		(axis == AXIS_X ? M(SLOPE_E) | M(SLOPE_STEEP_E) : M(SLOPE_W) | M(SLOPE_STEEP_W));
+	if (HASBIT(valid, tileh)) return _price.terraform;
+
+	return CMD_ERROR;
+}
+
+static int32 CheckBridgeSlopeSouth(Axis axis, Slope tileh)
+{
+	uint32 valid;
+
+	valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_SW) : M(SLOPE_SE));
+	if (HASBIT(valid, tileh)) return 0;
+
+	valid =
+		BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_S) | M(SLOPE_STEEP_S) |
+		(axis == AXIS_X ? M(SLOPE_W) | M(SLOPE_STEEP_W) : M(SLOPE_E) | M(SLOPE_STEEP_E));
+	if (HASBIT(valid, tileh)) return _price.terraform;
+
+	return CMD_ERROR;
+}
+#undef M
+
+
+uint32 GetBridgeLength(TileIndex begin, TileIndex end)
+{
+	int x1 = TileX(begin);
+	int y1 = TileY(begin);
+	int x2 = TileX(end);
+	int y2 = TileY(end);
+
+	return abs(x2 + y2 - x1 - y1) - 1;
+}
+
+bool CheckBridge_Stuff(byte bridge_type, uint bridge_len)
+{
+	const Bridge *b = &_bridge[bridge_type];
+	uint max; // max possible length of a bridge (with patch 100)
+
+	if (bridge_type >= MAX_BRIDGES) return false;
+	if (b->avail_year > _cur_year) return false;
+
+	max = b->max_length;
+	if (max >= 16 && _patches.longbridges) max = 100;
+
+	return b->min_length <= bridge_len && bridge_len <= max;
+}
+
+/** Build a Bridge
+ * @param end_tile end tile
+ * @param p1 packed start tile coords (~ dx)
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit 0- 7) - bridge type (hi bh)
+ * - p2 = (bit 8-..) - rail type. bit15 ((x>>8)&0x80) means road bridge.
+ */
+int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	int bridge_type;
+	TransportType transport;
+	RailType railtype;
+	uint x;
+	uint y;
+	uint sx;
+	uint sy;
+	TileIndex tile_start;
+	TileIndex tile_end;
+	Slope tileh_start;
+	Slope tileh_end;
+	uint z_start;
+	uint z_end;
+	TileIndex tile;
+	TileIndexDiff delta;
+	uint bridge_len;
+	Axis direction;
+	int32 cost, terraformcost, ret;
+	bool allow_on_slopes;
+
+	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
+
+	/* unpack parameters */
+	bridge_type = GB(p2, 0, 8);
+
+	if (p1 >= MapSize()) return CMD_ERROR;
+
+	// type of bridge
+	if (HASBIT(p2, 15)) {
+		railtype = 0;
+		transport = TRANSPORT_ROAD;
+	} else {
+		if (!ValParamRailtype(GB(p2, 8, 8))) return CMD_ERROR;
+		railtype = GB(p2, 8, 8);
+		transport = TRANSPORT_RAIL;
+	}
+
+	x = TileX(end_tile);
+	y = TileY(end_tile);
+	sx = TileX(p1);
+	sy = TileY(p1);
+
+	/* check if valid, and make sure that (x,y) are smaller than (sx,sy) */
+	if (x == sx) {
+		if (y == sy) return_cmd_error(STR_5008_CANNOT_START_AND_END_ON);
+		direction = AXIS_Y;
+		if (y > sy) uintswap(y,sy);
+	} else if (y == sy) {
+		direction = AXIS_X;
+		if (x > sx) uintswap(x,sx);
+	} else {
+		return_cmd_error(STR_500A_START_AND_END_MUST_BE_IN);
+	}
+
+	/* set and test bridge length, availability */
+	bridge_len = sx + sy - x - y - 1;
+	if (!CheckBridge_Stuff(bridge_type, bridge_len)) return_cmd_error(STR_5015_CAN_T_BUILD_BRIDGE_HERE);
+
+	/* retrieve landscape height and ensure it's on land */
+	tile_start = TileXY(x, y);
+	tile_end = TileXY(sx, sy);
+	if (IsClearWaterTile(tile_start) || IsClearWaterTile(tile_end)) {
+		return_cmd_error(STR_02A0_ENDS_OF_BRIDGE_MUST_BOTH);
+	}
+
+	tileh_start = GetTileSlope(tile_start, &z_start);
+	tileh_end = GetTileSlope(tile_end, &z_end);
+
+	if (IsSteepSlope(tileh_start)) z_start += TILE_HEIGHT;
+	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_start)) {
+		z_start += TILE_HEIGHT;
+		tileh_start = SLOPE_FLAT;
+	}
+
+	if (IsSteepSlope(tileh_end)) z_end += TILE_HEIGHT;
+	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_end)) {
+		z_end += TILE_HEIGHT;
+		tileh_end = SLOPE_FLAT;
+	}
+
+	if (z_start != z_end) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
+
+	// Towns are not allowed to use bridges on slopes.
+	allow_on_slopes = (!_is_old_ai_player
+	                   && _current_player != OWNER_TOWN && _patches.build_on_slopes);
+
+	/* Try and clear the start landscape */
+
+	ret = DoCommand(tile_start, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+	if (CmdFailed(ret)) return ret;
+	cost = ret;
+
+	terraformcost = CheckBridgeSlopeNorth(direction, tileh_start);
+	if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
+		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
+	cost += terraformcost;
+
+	/* Try and clear the end landscape */
+
+	ret = DoCommand(tile_end, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+	if (CmdFailed(ret)) return ret;
+	cost += ret;
+
+	// false - end tile slope check
+	terraformcost = CheckBridgeSlopeSouth(direction, tileh_end);
+	if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
+		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
+	cost += terraformcost;
+
+	{
+		TileIndex Heads[] = {tile_start, tile_end};
+		int i;
+
+		for (i = 0; i < 2; i++) {
+			if (MayHaveBridgeAbove(Heads[i])) {
+				if (IsBridgeAbove(Heads[i])) {
+					TileIndex north_head = GetNorthernBridgeEnd(Heads[i]);
+
+					if (direction == GetBridgeAxis(Heads[i])) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+
+					if (z_start + TILE_HEIGHT == GetBridgeHeight(north_head)) {
+						return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+					}
+				}
+			}
+		}
+	}
+
+	/* do the drill? */
+	if (flags & DC_EXEC) {
+		DiagDirection dir = AxisToDiagDir(direction);
+
+		if (transport == TRANSPORT_RAIL) {
+			MakeRailBridgeRamp(tile_start, _current_player, bridge_type, dir, railtype);
+			MakeRailBridgeRamp(tile_end,   _current_player, bridge_type, ReverseDiagDir(dir), railtype);
+		} else {
+			MakeRoadBridgeRamp(tile_start, _current_player, bridge_type, dir);
+			MakeRoadBridgeRamp(tile_end,   _current_player, bridge_type, ReverseDiagDir(dir));
+		}
+		MarkTileDirtyByTile(tile_start);
+		MarkTileDirtyByTile(tile_end);
+	}
+
+	delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
+	for (tile = tile_start + delta; tile != tile_end; tile += delta) {
+		uint z;
+
+		if (GetTileSlope(tile, &z) != SLOPE_FLAT && z >= z_start) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
+
+		if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
+			/* Disallow crossing bridges for the time being */
+			return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+		}
+
+		switch (GetTileType(tile)) {
+			case MP_WATER:
+				if (!EnsureNoVehicle(tile)) return_cmd_error(STR_980E_SHIP_IN_THE_WAY);
+				if (!IsWater(tile) && !IsCoast(tile)) goto not_valid_below;
+				break;
+
+			case MP_RAILWAY:
+				if (!IsPlainRailTile(tile)) goto not_valid_below;
+				break;
+
+			case MP_STREET:
+				if (GetRoadTileType(tile) == ROAD_TILE_DEPOT) goto not_valid_below;
+				break;
+
+			case MP_TUNNEL:
+				break;
+
+			case MP_STREET_BRIDGE:
+			case MP_RAILWAY_BRIDGE:
+				if (direction == DiagDirToAxis(GetBridgeRampDirection(tile))) goto not_valid_below;
+				if (z_start < GetBridgeHeight(tile)) goto not_valid_below;
+				break;
+
+			case MP_UNMOVABLE:
+				if (!IsOwnedLand(tile)) goto not_valid_below;
+				break;
+
+			case MP_CLEAR:
+				if (IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+				break;
+
+			default:
+not_valid_below:;
+				/* try and clear the middle landscape */
+				ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+				if (CmdFailed(ret)) return ret;
+				cost += ret;
+				break;
+		}
+
+		if (flags & DC_EXEC) {
+			SetBridgeMiddle(tile, direction);
+			MarkTileDirtyByTile(tile);
+		}
+	}
+
+	SetSignalsOnBothDir(tile_start, AxisToTrack(direction));
+	YapfNotifyTrackLayoutChange(tile_start, AxisToTrack(direction));
+
+	/* for human player that builds the bridge he gets a selection to choose from bridges (DC_QUERY_COST)
+	 * It's unnecessary to execute this command every time for every bridge. So it is done only
+	 * and cost is computed in "bridge_gui.c". For AI, Towns this has to be of course calculated
+	 */
+	if (!(flags & DC_QUERY_COST)) {
+		const Bridge *b = &_bridge[bridge_type];
+
+		bridge_len += 2; // begin and end tiles/ramps
+
+		if (IsValidPlayer(_current_player) && !_is_old_ai_player)
+			bridge_len = CalcBridgeLenCostFactor(bridge_len);
+
+		cost += (int64)bridge_len * _price.build_bridge * b->price >> 8;
+	}
+
+	return cost;
+}
+
+
+/** Build Tunnel.
+ * @param tile start tile of tunnel
+ * @param p1 railtype, 0x200 for road tunnel
+ * @param p2 unused
+ */
+int32 CmdBuildTunnel(TileIndex start_tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	TileIndexDiff delta;
+	TileIndex end_tile;
+	DiagDirection direction;
+	Slope start_tileh;
+	Slope end_tileh;
+	uint start_z;
+	uint end_z;
+	int32 cost;
+	int32 ret;
+
+	_build_tunnel_endtile = 0;
+
+	if (p1 != 0x200 && !ValParamRailtype(p1)) return CMD_ERROR;
+
+	start_tileh = GetTileSlope(start_tile, &start_z);
+
+	switch (start_tileh) {
+		case SLOPE_SW: direction = DIAGDIR_SW; break;
+		case SLOPE_SE: direction = DIAGDIR_SE; break;
+		case SLOPE_NW: direction = DIAGDIR_NW; break;
+		case SLOPE_NE: direction = DIAGDIR_NE; break;
+		default: return_cmd_error(STR_500B_SITE_UNSUITABLE_FOR_TUNNEL);
+	}
+
+	ret = DoCommand(start_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+	if (CmdFailed(ret)) return ret;
+
+	/* XXX - do NOT change 'ret' in the loop, as it is used as the price
+	 * for the clearing of the entrance of the tunnel. Assigning it to
+	 * cost before the loop will yield different costs depending on start-
+	 * position, because of increased-cost-by-length: 'cost += cost >> 3' */
+	cost = 0;
+	delta = TileOffsByDiagDir(direction);
+	end_tile = start_tile;
+	for (;;) {
+		end_tile += delta;
+		end_tileh = GetTileSlope(end_tile, &end_z);
+
+		if (start_z == end_z) break;
+
+		if (!_cheats.crossing_tunnels.value && IsTunnelInWay(end_tile, start_z)) {
+			return_cmd_error(STR_5003_ANOTHER_TUNNEL_IN_THE_WAY);
+		}
+
+		cost += _price.build_tunnel;
+		cost += cost >> 3; // add a multiplier for longer tunnels
+		if (cost >= 400000000) cost = 400000000;
+	}
+
+	/* Add the cost of the entrance */
+	cost += _price.build_tunnel + ret;
+
+	// if the command fails from here on we want the end tile to be highlighted
+	_build_tunnel_endtile = end_tile;
+
+	// slope of end tile must be complementary to the slope of the start tile
+	if (end_tileh != ComplementSlope(start_tileh)) {
+		ret = DoCommand(end_tile, end_tileh & start_tileh, 0, flags, CMD_TERRAFORM_LAND);
+		if (CmdFailed(ret)) return_cmd_error(STR_5005_UNABLE_TO_EXCAVATE_LAND);
+	} else {
+		ret = DoCommand(end_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+		if (CmdFailed(ret)) return ret;
+	}
+	cost += _price.build_tunnel + ret;
+
+	if (flags & DC_EXEC) {
+		if (GB(p1, 9, 1) == TRANSPORT_RAIL) {
+			MakeRailTunnel(start_tile, _current_player, direction,                 GB(p1, 0, 4));
+			MakeRailTunnel(end_tile,   _current_player, ReverseDiagDir(direction), GB(p1, 0, 4));
+			UpdateSignalsOnSegment(start_tile, direction);
+			YapfNotifyTrackLayoutChange(start_tile, AxisToTrack(DiagDirToAxis(direction)));
+		} else {
+			MakeRoadTunnel(start_tile, _current_player, direction);
+			MakeRoadTunnel(end_tile,   _current_player, ReverseDiagDir(direction));
+		}
+	}
+
+	return cost;
+}
+
+TileIndex CheckTunnelBusy(TileIndex tile, uint *length)
+{
+	uint z = GetTileZ(tile);
+	DiagDirection dir = GetTunnelDirection(tile);
+	TileIndexDiff delta = TileOffsByDiagDir(dir);
+	uint len = 0;
+	TileIndex starttile = tile;
+	Vehicle *v;
+
+	do {
+		tile += delta;
+		len++;
+	} while (
+		!IsTunnelTile(tile) ||
+		ReverseDiagDir(GetTunnelDirection(tile)) != dir ||
+		GetTileZ(tile) != z
+	);
+
+	v = FindVehicleBetween(starttile, tile, z);
+	if (v != NULL) {
+		_error_message = v->type == VEH_Train ?
+			STR_5000_TRAIN_IN_TUNNEL : STR_5001_ROAD_VEHICLE_IN_TUNNEL;
+		return INVALID_TILE;
+	}
+
+	if (length != NULL) *length = len;
+	return tile;
+}
+
+static inline bool CheckAllowRemoveTunnelBridge(TileIndex tile)
+{
+	/* Floods can remove anything as well as the scenario editor */
+	if (_current_player == OWNER_WATER || _game_mode == GM_EDITOR) return true;
+	/* Obviously if the bridge/tunnel belongs to us, or no-one, we can remove it */
+	if (CheckTileOwnership(tile) || IsTileOwner(tile, OWNER_NONE)) return true;
+	/* Otherwise we can only remove town-owned stuff with extra patch-settings, or cheat */
+	if (IsTileOwner(tile, OWNER_TOWN) && (_patches.extra_dynamite || _cheats.magic_bulldozer.value)) return true;
+	return false;
+}
+
+static int32 DoClearTunnel(TileIndex tile, uint32 flags)
+{
+	Town *t = NULL;
+	TileIndex endtile;
+	uint length;
+
+	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
+
+	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
+
+	endtile = CheckTunnelBusy(tile, &length);
+	if (endtile == INVALID_TILE) return CMD_ERROR;
+
+	_build_tunnel_endtile = endtile;
+
+	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
+		t = ClosestTownFromTile(tile, (uint)-1); // town penalty rating
+
+		/* Check if you are allowed to remove the tunnel owned by a town
+		 * Removal depends on difficulty settings */
+		if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
+			SetDParam(0, t->index);
+			return_cmd_error(STR_2009_LOCAL_AUTHORITY_REFUSES);
+		}
+	}
+
+	if (flags & DC_EXEC) {
+		// We first need to request the direction before calling DoClearSquare
+		//  else the direction is always 0.. dah!! ;)
+		DiagDirection dir = GetTunnelDirection(tile);
+		Track track;
+
+		// Adjust the town's player rating. Do this before removing the tile owner info.
+		if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR)
+			ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM);
+
+		DoClearSquare(tile);
+		DoClearSquare(endtile);
+		UpdateSignalsOnSegment(tile, ReverseDiagDir(dir));
+		UpdateSignalsOnSegment(endtile, dir);
+		track = AxisToTrack(DiagDirToAxis(dir));
+		YapfNotifyTrackLayoutChange(tile, track);
+		YapfNotifyTrackLayoutChange(endtile, track);
+	}
+	return _price.clear_tunnel * (length + 1);
+}
+
+
+static bool IsVehicleOnBridge(TileIndex starttile, TileIndex endtile, uint z)
+{
+	const Vehicle *v;
+	FOR_ALL_VEHICLES(v) {
+		if ((v->tile == starttile || v->tile == endtile) && v->z_pos == z) {
+			_error_message = VehicleInTheWayErrMsg(v);
+			return true;
+		}
+	}
+	return false;
+}
+
+static int32 DoClearBridge(TileIndex tile, uint32 flags)
+{
+	DiagDirection direction;
+	TileIndexDiff delta;
+	TileIndex endtile;
+	Town *t = NULL;
+
+	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
+
+	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
+
+	endtile = GetOtherBridgeEnd(tile);
+
+	if (!EnsureNoVehicle(tile) ||
+			!EnsureNoVehicle(endtile) ||
+			IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
+		return CMD_ERROR;
+	}
+
+	direction = GetBridgeRampDirection(tile);
+	delta = TileOffsByDiagDir(direction);
+
+	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
+		t = ClosestTownFromTile(tile, (uint)-1); // town penalty rating
+
+		/* Check if you are allowed to remove the bridge owned by a town
+		 * Removal depends on difficulty settings */
+		if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
+			SetDParam(0, t->index);
+			return_cmd_error(STR_2009_LOCAL_AUTHORITY_REFUSES);
+		}
+	}
+
+	if (flags & DC_EXEC) {
+		TileIndex c;
+		Track track;
+
+		//checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
+		// you have a "Poor" (0) town rating
+		if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR)
+			ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM);
+
+		DoClearSquare(tile);
+		DoClearSquare(endtile);
+		for (c = tile + delta; c != endtile; c += delta) {
+				ClearBridgeMiddle(c);
+			MarkTileDirtyByTile(c);
+		}
+
+		UpdateSignalsOnSegment(tile, ReverseDiagDir(direction));
+		UpdateSignalsOnSegment(endtile, direction);
+		track = AxisToTrack(DiagDirToAxis(direction));
+		YapfNotifyTrackLayoutChange(tile, track);
+		YapfNotifyTrackLayoutChange(endtile, track);
+	}
+
+	return (DistanceManhattan(tile, endtile) + 1) * _price.clear_bridge;
+}
+
+static int32 ClearTile_Tunnel(TileIndex tile, byte flags)
+{
+	assert(IsTunnelTile(tile));
+	if (flags & DC_AUTO) return_cmd_error(STR_5006_MUST_DEMOLISH_TUNNEL_FIRST);
+	return DoClearTunnel(tile, flags);
+}
+
+static int32 ClearTile_Bridge(TileIndex tile, byte flags)
+{
+	assert(IsBridgeTile(tile));
+	if (flags & DC_AUTO) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+	return DoClearBridge(tile, flags);
+}
+
+int32 DoConvertTunnelBridgeRail(TileIndex tile, RailType totype, bool exec)
+{
+	TileIndex endtile;
+
+	if (IsTunnelTile(tile) && GetTunnelTransportType(tile) == TRANSPORT_RAIL) {
+		uint length;
+
+		if (!CheckTileOwnership(tile)) return CMD_ERROR;
+
+		if (GetRailType(tile) == totype) return CMD_ERROR;
+
+		// 'hidden' elrails can't be downgraded to normal rail when elrails are disabled
+		if (_patches.disable_elrails && totype == RAILTYPE_RAIL && GetRailType(tile) == RAILTYPE_ELECTRIC) return CMD_ERROR;
+
+		endtile = CheckTunnelBusy(tile, &length);
+		if (endtile == INVALID_TILE) return CMD_ERROR;
+
+		if (exec) {
+			Track track;
+			SetRailType(tile, totype);
+			SetRailType(endtile, totype);
+			MarkTileDirtyByTile(tile);
+			MarkTileDirtyByTile(endtile);
+
+			track = AxisToTrack(DiagDirToAxis(GetTunnelDirection(tile)));
+			YapfNotifyTrackLayoutChange(tile, track);
+			YapfNotifyTrackLayoutChange(endtile, track);
+		}
+		return (length + 1) * (_price.build_rail >> 1);
+	} else if (IsBridgeTile(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
+
+		if (!CheckTileOwnership(tile)) return CMD_ERROR;
+
+		endtile = GetOtherBridgeEnd(tile);
+
+		if (!EnsureNoVehicle(tile) ||
+				!EnsureNoVehicle(endtile) ||
+				IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
+			return CMD_ERROR;
+		}
+
+		if (GetRailType(tile) == totype) return CMD_ERROR;
+
+		if (exec) {
+			TileIndexDiff delta;
+			Track track;
+
+			SetRailType(tile, totype);
+			SetRailType(endtile, totype);
+			MarkTileDirtyByTile(tile);
+			MarkTileDirtyByTile(endtile);
+
+			track = AxisToTrack(DiagDirToAxis(GetBridgeRampDirection(tile)));
+			YapfNotifyTrackLayoutChange(tile, track);
+			YapfNotifyTrackLayoutChange(endtile, track);
+
+			delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));
+			for (tile += delta; tile != endtile; tile += delta) {
+				MarkTileDirtyByTile(tile); // TODO encapsulate this into a function
+			}
+		}
+
+		return (DistanceManhattan(tile, endtile) + 1) * (_price.build_rail >> 1);
+	} else {
+		return CMD_ERROR;
+	}
+}
+
+
+static void DrawBridgePillars(PalSpriteID image, const TileInfo* ti, Axis axis, uint type, int x, int y, int z)
+{
+	if (image != 0) {
+		bool drawfarpillar = !HASBIT(GetBridgeFlags(type), 0);
+		int back_height, front_height;
+		int i = z;
+		const byte *p;
+
+		static const byte _tileh_bits[4][8] = {
+			{ 2, 1, 8, 4,  16,  2, 0, 9 },
+			{ 1, 8, 4, 2,   2, 16, 9, 0 },
+			{ 4, 8, 1, 2,  16,  2, 0, 9 },
+			{ 2, 4, 8, 1,   2, 16, 9, 0 }
+		};
+
+		if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+
+		p = _tileh_bits[(image & 1) * 2 + (axis == AXIS_X ? 0 : 1)];
+		front_height = ti->z + (ti->tileh & p[0] ? TILE_HEIGHT : 0);
+		back_height  = ti->z + (ti->tileh & p[1] ? TILE_HEIGHT : 0);
+
+		if (IsSteepSlope(ti->tileh)) {
+			if (!(ti->tileh & p[2])) front_height += TILE_HEIGHT;
+			if (!(ti->tileh & p[3])) back_height  += TILE_HEIGHT;
+		}
+
+		for (; z >= front_height || z >= back_height; z -= TILE_HEIGHT) {
+			/* HACK set height of the BB of pillars to 1, because the origin of the
+			 * sprites is at the top
+			 */
+			if (z >= front_height) { // front facing pillar
+				AddSortableSpriteToDraw(image, x, y, p[4], p[5], 1, z);
+			}
+
+			if (drawfarpillar && z >= back_height && z < i - TILE_HEIGHT) { // back facing pillar
+				AddSortableSpriteToDraw(image, x - p[6], y - p[7], p[4], p[5], 1, z);
+			}
+		}
+	}
+}
+
+uint GetBridgeFoundation(Slope tileh, Axis axis)
+{
+	uint i;
+
+	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) return tileh;
+
+	// inclined sloped building
+	switch (tileh) {
+		case SLOPE_W:
+		case SLOPE_STEEP_W: i = 0; break;
+		case SLOPE_S:
+		case SLOPE_STEEP_S: i = 2; break;
+		case SLOPE_E:
+		case SLOPE_STEEP_E: i = 4; break;
+		case SLOPE_N:
+		case SLOPE_STEEP_N: i = 6; break;
+		default: return 0;
+	}
+	if (axis != AXIS_X) ++i;
+	return i + 15;
+}
+
+/**
+ * Draws a tunnel tile.
+ * Please note that in this code, "roads" are treated as railtype 1, whilst the real railtypes are 0, 2 and 3
+ */
+static void DrawTile_Tunnel(TileInfo *ti)
+{
+	uint32 image;
+
+	if (GetTunnelTransportType(ti->tile) == TRANSPORT_RAIL) {
+		image = GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.tunnel;
+	} else {
+		image = SPR_TUNNEL_ENTRY_REAR_ROAD;
+	}
+
+	if (HasTunnelSnowOrDesert(ti->tile)) image += 32;
+
+	image += GetTunnelDirection(ti->tile) * 2;
+	DrawGroundSprite(image);
+	if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+	AddSortableSpriteToDraw(image+1, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, 1, 1, 8, (byte)ti->z);
+	DrawBridgeMiddle(ti);
+}
+
+/**
+ * Draws a bridge tile.
+ * base_offset is where the sprite selection comes into play
+ * and it works a bit like a bitmask.<p> For bridge heads:
+ * <ul><li>Bit 0: direction</li>
+ * <li>Bit 1: northern or southern heads</li>
+ * <li>Bit 2: Set if the bridge head is sloped</li>
+ * <li>Bit 3 and more: Railtype Specific subset</li>
+ * </ul>
+ * Please note that in this code, "roads" are treated as railtype 1, whilst the real railtypes are 0, 2 and 3
+ */
+static void DrawTile_Bridge(TileInfo *ti)
+{
+	uint32 image;
+
+	int base_offset;
+	bool ice = HasBridgeSnowOrDesert(ti->tile);
+
+	if (GetBridgeTransportType(ti->tile) == TRANSPORT_RAIL) {
+		base_offset = GetRailTypeInfo(GetRailType(ti->tile))->bridge_offset;
+		assert(base_offset != 8); /* This one is used for roads */
+	} else {
+		base_offset = 8;
+	}
+
+	/* as the lower 3 bits are used for other stuff, make sure they are clear */
+	assert( (base_offset & 0x07) == 0x00);
+
+	if (!HASBIT(BRIDGE_NO_FOUNDATION, ti->tileh)) {
+		int f = GetBridgeFoundation(ti->tileh, DiagDirToAxis(GetBridgeRampDirection(ti->tile)));
+		if (f != 0) DrawFoundation(ti, f);
+	}
+
+	// HACK Wizardry to convert the bridge ramp direction into a sprite offset
+	base_offset += (6 - GetBridgeRampDirection(ti->tile)) % 4;
+
+	if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
+
+	/* Table number 6 always refers to the bridge heads for any bridge type */
+	image = GetBridgeSpriteTable(GetBridgeType(ti->tile), 6)[base_offset];
+
+	if (!ice) {
+		DrawClearLandTile(ti, 3);
+	} else {
+		DrawGroundSprite(SPR_FLAT_SNOWY_TILE + _tileh_to_sprite[ti->tileh]);
+	}
+
+	if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+	// draw ramp
+	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+	/* HACK set the height of the BB of a sloped ramp to 1 so a vehicle on
+	 * it doesn't disappear behind it
+	 */
+	AddSortableSpriteToDraw(
+		image, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 1 : 8, ti->z
+	);
+
+	DrawBridgeMiddle(ti);
+}
+
+
+/** Compute bridge piece. Computes the bridge piece to display depending on the position inside the bridge.
+ * bridges pieces sequence (middle parts)
+ * bridge len 1: 0
+ * bridge len 2: 0 1
+ * bridge len 3: 0 4 1
+ * bridge len 4: 0 2 3 1
+ * bridge len 5: 0 2 5 3 1
+ * bridge len 6: 0 2 3 2 3 1
+ * bridge len 7: 0 2 3 4 2 3 1
+ * #0 - always as first, #1 - always as last (if len>1)
+ * #2,#3 are to pair in order
+ * for odd bridges: #5 is going in the bridge middle if on even position, #4 on odd (counting from 0)
+ * @param north Northernmost tile of bridge
+ * @param south Southernmost tile of bridge
+ * @return Index of bridge piece
+ */
+static uint CalcBridgePiece(uint north, uint south)
+{
+	if (north == 1) {
+		return 0;
+	} else if (south == 1) {
+		return 1;
+	} else if (north < south) {
+		return north & 1 ? 3 : 2;
+	} else if (north > south) {
+		return south & 1 ? 2 : 3;
+	} else {
+		return north & 1 ? 5 : 4;
+	}
+}
+
+
+void DrawBridgeMiddle(const TileInfo* ti)
+{
+	const PalSpriteID* b;
+	PalSpriteID image;
+	uint base_offset;
+	TileIndex rampnorth;
+	TileIndex rampsouth;
+	Axis axis;
+	uint piece;
+	uint type;
+	int x;
+	int y;
+	uint z;
+
+	if (!IsBridgeAbove(ti->tile)) return;
+
+	rampnorth = GetNorthernBridgeEnd(ti->tile);
+	rampsouth = GetSouthernBridgeEnd(ti->tile);
+
+	axis = GetBridgeAxis(ti->tile);
+	piece = CalcBridgePiece(
+		DistanceManhattan(ti->tile, rampnorth),
+		DistanceManhattan(ti->tile, rampsouth)
+	);
+	type = GetBridgeType(rampsouth);
+
+	if (GetBridgeTransportType(rampsouth) == TRANSPORT_RAIL) {
+		base_offset = GetRailTypeInfo(GetRailType(rampsouth))->bridge_offset;
+	} else {
+		base_offset = 8;
+	}
+
+	b = base_offset + GetBridgeSpriteTable(type, piece);
+	if (axis != AXIS_X) b += 4;
+
+	x = ti->x;
+	y = ti->y;
+	z = GetBridgeHeight(rampsouth) - 3;
+
+	image = b[0];
+	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+	if (axis == AXIS_X) {
+		AddSortableSpriteToDraw(image, x, y, 16, 11, 1, z);
+	} else {
+		AddSortableSpriteToDraw(image, x, y, 11, 16, 1, z);
+	}
+
+	image = b[1];
+	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+
+	// draw roof, the component of the bridge which is logically between the vehicle and the camera
+	if (axis == AXIS_X) {
+		y += 12;
+		if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 16, 1, 0x28, z);
+	} else {
+		x += 12;
+		if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 1, 16, 0x28, z);
+	}
+
+	if (GetRailType(rampsouth) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+	if (ti->z + 5 == z) {
+		// draw poles below for small bridges
+		image = b[2];
+		if (image != 0) {
+			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+			DrawGroundSpriteAt(image, x, y, z);
+		}
+	} else if (_patches.bridge_pillars) {
+		// draw pillars below for high bridges
+		DrawBridgePillars(b[2], ti, axis, type, x, y, z);
+	}
+}
+
+
+uint SetSpeedLimitOnBridge(Vehicle *v)
+{
+	uint bridge_speed;
+	if (v->vehstatus & VS_HIDDEN) return v->max_speed; /* in tunnel */
+
+	bridge_speed = _bridge[GetBridgeType(v->tile)].speed;
+
+	if (v->type == VEH_Road) bridge_speed *= 2; /* XXX give vehicles proper speeds */
+
+	if (v->cur_speed > bridge_speed) v->cur_speed = bridge_speed;
+	return bridge_speed;
+}
+
+
+/** Gets the absolute z coordinate of a point inside a tunnel tile
+ *  When we're on the track (that means between position 5 and 10)
+ *  on the coordinate perpendicular to the track it returns only the
+ *  base height of the tile (because the track is horizontal).
+ *  Outside this range (from 0 to 4 and from 11 to 15) it returns the
+ *  "true" Z coordinate of the tile by taking the slope into account
+ *  @param tile The index of the tile we are talking about
+ *  @param x Absolute or relative x coordinate
+ *  @param y Absolute or relative y coordinate
+ *  @return Absolute z coordinate
+ */
+static uint GetSlopeZ_Tunnel(TileIndex tile, uint x, uint y)
+{
+	uint z, pos;
+	Slope tileh = GetTileSlope(tile, &z);
+
+	x &= 0xF;
+	y &= 0xF;
+
+	pos = (DiagDirToAxis(GetTunnelDirection(tile)) == AXIS_X ? y : x);
+
+	// In the tunnel entrance?
+	if (5 <= pos && pos <= 10) return z;
+
+	return z + GetPartialZ(x, y, tileh);
+}
+
+/** Gets the absolute z coordinate of a point inside a bridge tile
+ *  When we're on the track (that means between position 5 and 10)
+ *  on the coordinate perpendicular to the track it returns the base
+ *  height of the ramp
+ *  Outside this range (from 0 to 4 and from 11 to 15) it returns the
+ *  "true" Z coordinate of the tile by taking the slope into account
+ *  @param tile The index of the tile we are talking about
+ *  @param x Absolute or relative x coordinate
+ *  @param y Absolute or relative y coordinate
+ *  @return Absolute z coordinate
+ */
+static uint GetSlopeZ_Bridge(TileIndex tile, uint x, uint y)
+{
+	uint z, pos;
+	Slope tileh = GetTileSlope(tile, &z);
+	DiagDirection dir = GetBridgeRampDirection(tile);
+
+	x &= 0xF;
+	y &= 0xF;
+
+	pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
+
+	// On the bridge ramp?
+	if (5 <= pos && pos <= 10) {
+		uint delta;
+
+		if (IsSteepSlope(tileh)) return z + TILE_HEIGHT * 2;
+
+		if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + TILE_HEIGHT;
+
+		if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += TILE_HEIGHT;
+		switch (dir) {
+			default: NOT_REACHED();
+			case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
+			case DIAGDIR_SE: delta = y / 2; break;
+			case DIAGDIR_SW: delta = x / 2; break;
+			case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
+		}
+		return z + 1 + delta;
+	} else {
+		uint f = GetBridgeFoundation(tileh, DiagDirToAxis(dir));
+
+		if (f != 0) {
+			if (IsSteepSlope(tileh)) {
+				z += TILE_HEIGHT;
+			} else if (f < 15) {
+				return z + TILE_HEIGHT;
+			}
+			tileh = _inclined_tileh[f - 15];
+		}
+	}
+	return z + GetPartialZ(x, y, tileh);
+}
+
+static Slope GetSlopeTileh_Tunnel(TileIndex tile, Slope tileh)
+{
+	return tileh;
+}
+
+static Slope GetSlopeTileh_Bridge(TileIndex tile, Slope tileh)
+{
+	if (HASBIT(BRIDGE_NO_FOUNDATION, tileh)) {
+		return tileh;
+	} else {
+		uint f = GetBridgeFoundation(tileh, DiagDirToAxis(GetBridgeRampDirection(tile)));
+
+		if (f == 0) return tileh;
+		if (f < 15) return SLOPE_FLAT;
+		return _inclined_tileh[f - 15];
+	}
+}
+
+static void GetAcceptedCargo_Tunnel(TileIndex tile, AcceptedCargo ac)
+{
+	/* not used */
+}
+
+static void GetAcceptedCargo_Bridge(TileIndex tile, AcceptedCargo ac)
+{
+	/* not used */
+}
+
+static const StringID _bridge_tile_str[(MAX_BRIDGES + 3) + (MAX_BRIDGES + 3)] = {
+	STR_501F_WOODEN_RAIL_BRIDGE,
+	STR_5020_CONCRETE_RAIL_BRIDGE,
+	STR_501C_STEEL_GIRDER_RAIL_BRIDGE,
+	STR_501E_REINFORCED_CONCRETE_SUSPENSION,
+	STR_501B_STEEL_SUSPENSION_RAIL_BRIDGE,
+	STR_501B_STEEL_SUSPENSION_RAIL_BRIDGE,
+	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+	STR_501C_STEEL_GIRDER_RAIL_BRIDGE,
+	STR_5027_TUBULAR_RAIL_BRIDGE,
+	STR_5027_TUBULAR_RAIL_BRIDGE,
+	STR_5027_TUBULAR_RAIL_BRIDGE,
+	0, 0, 0,
+
+	STR_5025_WOODEN_ROAD_BRIDGE,
+	STR_5026_CONCRETE_ROAD_BRIDGE,
+	STR_5022_STEEL_GIRDER_ROAD_BRIDGE,
+	STR_5024_REINFORCED_CONCRETE_SUSPENSION,
+	STR_5021_STEEL_SUSPENSION_ROAD_BRIDGE,
+	STR_5021_STEEL_SUSPENSION_ROAD_BRIDGE,
+	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+	STR_5022_STEEL_GIRDER_ROAD_BRIDGE,
+	STR_5028_TUBULAR_ROAD_BRIDGE,
+	STR_5028_TUBULAR_ROAD_BRIDGE,
+	STR_5028_TUBULAR_ROAD_BRIDGE,
+	0, 0, 0,
+};
+
+static void GetTileDesc_Tunnel(TileIndex tile, TileDesc *td)
+{
+	td->str = (GetTunnelTransportType(tile) == TRANSPORT_RAIL) ?  STR_5017_RAILROAD_TUNNEL : STR_5018_ROAD_TUNNEL;
+	td->owner = GetTileOwner(tile);
+}
+
+static void GetTileDesc_Bridge(TileIndex tile, TileDesc *td)
+{
+	td->str = _bridge_tile_str[GetBridgeTransportType(tile) << 4 | GetBridgeType(tile)];
+	td->owner = GetTileOwner(tile);
+}
+
+
+static void AnimateTile_Tunnel(TileIndex tile)
+{
+	/* not used */
+}
+
+static void AnimateTile_Bridge(TileIndex tile)
+{
+	/* not used */
+}
+
+static void TileLoop_Tunnel(TileIndex tile)
+{
+	bool snow_or_desert = HasTunnelSnowOrDesert(tile);
+	switch (_opt.landscape) {
+		case LT_HILLY:
+			if (snow_or_desert != (GetTileZ(tile) > _opt.snow_line)) {
+				SetTunnelSnowOrDesert(tile, !snow_or_desert);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+
+		case LT_DESERT:
+			if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
+				SetTunnelSnowOrDesert(tile, true);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+	}
+}
+
+static void TileLoop_Bridge(TileIndex tile)
+{
+	bool snow_or_desert = HasBridgeSnowOrDesert(tile);
+	switch (_opt.landscape) {
+		case LT_HILLY:
+			if (snow_or_desert != (GetTileZ(tile) > _opt.snow_line)) {
+				SetBridgeSnowOrDesert(tile, !snow_or_desert);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+
+		case LT_DESERT:
+			if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
+				SetBridgeSnowOrDesert(tile, true);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+	}
+}
+
+static void ClickTile_Tunnel(TileIndex tile)
+{
+	/* not used */
+}
+
+static void ClickTile_Bridge(TileIndex tile)
+{
+	/* not used */
+}
+
+
+static uint32 GetTileTrackStatus_Tunnel(TileIndex tile, TransportType mode)
+{
+	if (GetTunnelTransportType(tile) != mode) return 0;
+	return AxisToTrackBits(DiagDirToAxis(GetTunnelDirection(tile))) * 0x101;
+}
+
+static uint32 GetTileTrackStatus_Bridge(TileIndex tile, TransportType mode)
+{
+	if (GetBridgeTransportType(tile) != mode) return 0;
+	return AxisToTrackBits(DiagDirToAxis(GetBridgeRampDirection(tile))) * 0x101;
+}
+
+static void ChangeTileOwner_Tunnel(TileIndex tile, PlayerID old_player, PlayerID new_player)
+{
+	if (!IsTileOwner(tile, old_player)) return;
+
+	if (new_player != PLAYER_SPECTATOR) {
+		SetTileOwner(tile, new_player);
+	} else {
+		DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+	}
+}
+
+static void ChangeTileOwner_Bridge(TileIndex tile, PlayerID old_player, PlayerID new_player)
+{
+	if (!IsTileOwner(tile, old_player)) return;
+
+	if (new_player != PLAYER_SPECTATOR) {
+		SetTileOwner(tile, new_player);
+	} else {
+		DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+	}
+}
+
+
+static const byte _tunnel_fractcoord_1[4]    = {0x8E, 0x18, 0x81, 0xE8};
+static const byte _tunnel_fractcoord_2[4]    = {0x81, 0x98, 0x87, 0x38};
+static const byte _tunnel_fractcoord_3[4]    = {0x82, 0x88, 0x86, 0x48};
+static const byte _exit_tunnel_track[4]      = {1, 2, 1, 2};
+
+static const byte _road_exit_tunnel_state[4] = {8, 9, 0, 1};
+static const byte _road_exit_tunnel_frame[4] = {2, 7, 9, 4};
+
+static const byte _tunnel_fractcoord_4[4]    = {0x52, 0x85, 0x98, 0x29};
+static const byte _tunnel_fractcoord_5[4]    = {0x92, 0x89, 0x58, 0x25};
+static const byte _tunnel_fractcoord_6[4]    = {0x92, 0x89, 0x56, 0x45};
+static const byte _tunnel_fractcoord_7[4]    = {0x52, 0x85, 0x96, 0x49};
+
+static uint32 VehicleEnter_Tunnel(Vehicle *v, TileIndex tile, int x, int y)
+{
+	int z = GetSlopeZ(x, y) - v->z_pos;
+
+	byte fc;
+	DiagDirection dir;
+	DiagDirection vdir;
+
+	if (myabs(z) > 2) return 8;
+
+	if (v->type == VEH_Train) {
+		fc = (x & 0xF) + (y << 4);
+
+		dir = GetTunnelDirection(tile);
+		vdir = DirToDiagDir(v->direction);
+
+		if (v->u.rail.track != 0x40 && dir == vdir) {
+			if (IsFrontEngine(v) && fc == _tunnel_fractcoord_1[dir]) {
+				if (!PlayVehicleSound(v, VSE_TUNNEL) && v->spritenum < 4) {
+					SndPlayVehicleFx(SND_05_TRAIN_THROUGH_TUNNEL, v);
+				}
+				return 0;
+			}
+			if (fc == _tunnel_fractcoord_2[dir]) {
+				v->tile = tile;
+				v->u.rail.track = 0x40;
+				v->vehstatus |= VS_HIDDEN;
+				return 4;
+			}
+		}
+
+		if (dir == ReverseDiagDir(vdir) && fc == _tunnel_fractcoord_3[dir] && z == 0) {
+			/* We're at the tunnel exit ?? */
+			v->tile = tile;
+			v->u.rail.track = _exit_tunnel_track[dir];
+			assert(v->u.rail.track);
+			v->vehstatus &= ~VS_HIDDEN;
+			return 4;
+		}
+	} else if (v->type == VEH_Road) {
+		fc = (x & 0xF) + (y << 4);
+		dir = GetTunnelDirection(tile);
+		vdir = DirToDiagDir(v->direction);
+
+		// Enter tunnel?
+		if (v->u.road.state != 0xFF && dir == vdir) {
+			if (fc == _tunnel_fractcoord_4[dir] ||
+					fc == _tunnel_fractcoord_5[dir]) {
+				v->tile = tile;
+				v->u.road.state = 0xFF;
+				v->vehstatus |= VS_HIDDEN;
+				return 4;
+			} else {
+				return 0;
+			}
+		}
+
+		if (dir == ReverseDiagDir(vdir) && (
+					/* We're at the tunnel exit ?? */
+					fc == _tunnel_fractcoord_6[dir] ||
+					fc == _tunnel_fractcoord_7[dir]
+				) &&
+				z == 0) {
+			v->tile = tile;
+			v->u.road.state = _road_exit_tunnel_state[dir];
+			v->u.road.frame = _road_exit_tunnel_frame[dir];
+			v->vehstatus &= ~VS_HIDDEN;
+			return 4;
+		}
+	}
+	return 0;
+}
+
+static uint32 VehicleEnter_Bridge(Vehicle *v, TileIndex tile, int x, int y)
+{
+	int z = GetSlopeZ(x, y) - v->z_pos;
+
+	DiagDirection dir;
+
+	if (myabs(z) > 2) return 8;
+
+	if (v->type == VEH_Road || (v->type == VEH_Train && IsFrontEngine(v))) {
+		/* modify speed of vehicle */
+		uint16 spd = _bridge[GetBridgeType(tile)].speed;
+
+		if (v->type == VEH_Road) spd *= 2;
+		if (v->cur_speed > spd) v->cur_speed = spd;
+	}
+
+	dir = GetBridgeRampDirection(tile);
+	if (DirToDiagDir(v->direction) == dir) {
+		switch (dir) {
+			default: NOT_REACHED();
+			case DIAGDIR_NE: if ((x & 0xF) != 0)             return 0; break;
+			case DIAGDIR_SE: if ((y & 0xF) != TILE_SIZE - 1) return 0; break;
+			case DIAGDIR_SW: if ((x & 0xF) != TILE_SIZE - 1) return 0; break;
+			case DIAGDIR_NW: if ((y & 0xF) != 0)             return 0; break;
+		}
+		if (v->type == VEH_Train) {
+			v->u.rail.track = 0x40;
+			CLRBIT(v->u.rail.flags, VRF_GOINGUP);
+			CLRBIT(v->u.rail.flags, VRF_GOINGDOWN);
+		} else {
+			v->u.road.state = 0xFF;
+		}
+		return 4;
+	} else if (DirToDiagDir(v->direction) == ReverseDiagDir(dir)) {
+		v->tile = tile;
+		if (v->type == VEH_Train) {
+			if (v->u.rail.track == 0x40) {
+				v->u.rail.track = (DiagDirToAxis(dir) == AXIS_X ? 1 : 2);
+				return 4;
+			}
+		} else {
+			if (v->u.road.state == 0xFF) {
+				v->u.road.state = _road_exit_tunnel_state[dir];
+				v->u.road.frame = 0;
+				return 4;
+			}
+		}
+		return 0;
+	}
+	return 0;
+}
+
+const TileTypeProcs _tile_type_tunnel_procs = {
+	DrawTile_Tunnel,           /* draw_tile_proc */
+	GetSlopeZ_Tunnel,          /* get_slope_z_proc */
+	ClearTile_Tunnel,          /* clear_tile_proc */
+	GetAcceptedCargo_Tunnel,   /* get_accepted_cargo_proc */
+	GetTileDesc_Tunnel,        /* get_tile_desc_proc */
+	GetTileTrackStatus_Tunnel, /* get_tile_track_status_proc */
+	ClickTile_Tunnel,          /* click_tile_proc */
+	AnimateTile_Tunnel,        /* animate_tile_proc */
+	TileLoop_Tunnel,           /* tile_loop_clear */
+	ChangeTileOwner_Tunnel,    /* change_tile_owner_clear */
+	NULL,                            /* get_produced_cargo_proc */
+	VehicleEnter_Tunnel,       /* vehicle_enter_tile_proc */
+	GetSlopeTileh_Tunnel,      /* get_slope_tileh_proc */
+};
+
+const TileTypeProcs _tile_type_bridge_procs = {
+	DrawTile_Bridge,           /* draw_tile_proc */
+	GetSlopeZ_Bridge,          /* get_slope_z_proc */
+	ClearTile_Bridge,          /* clear_tile_proc */
+	GetAcceptedCargo_Bridge,   /* get_accepted_cargo_proc */
+	GetTileDesc_Bridge,        /* get_tile_desc_proc */
+	GetTileTrackStatus_Bridge, /* get_tile_track_status_proc */
+	ClickTile_Bridge,          /* click_tile_proc */
+	AnimateTile_Bridge,        /* animate_tile_proc */
+	TileLoop_Bridge,           /* tile_loop_clear */
+	ChangeTileOwner_Bridge,    /* change_tile_owner_clear */
+	NULL,                      /* get_produced_cargo_proc */
+	VehicleEnter_Bridge,       /* vehicle_enter_tile_proc */
+	GetSlopeTileh_Bridge,      /* get_slope_tileh_proc */
+};
diff -r 3e0dd1f014ca -r 04068f82afaa tunnel_cmd.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tunnel_cmd.c	Fri Dec 29 12:03:28 2006 +0000
@@ -0,0 +1,1415 @@
+/* $Id$ */
+
+/** @file tunnelbridge_cmd.c
+ * This file deals with tunnels and bridges (non-gui stuff)
+ * @todo seperate this file into two
+ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "bridge_map.h"
+#include "rail_map.h"
+#include "road_map.h"
+#include "table/sprites.h"
+#include "table/strings.h"
+#include "functions.h"
+#include "map.h"
+#include "tile.h"
+#include "tunnel_map.h"
+#include "unmovable_map.h"
+#include "vehicle.h"
+#include "viewport.h"
+#include "command.h"
+#include "player.h"
+#include "town.h"
+#include "sound.h"
+#include "variables.h"
+#include "bridge.h"
+#include "train.h"
+#include "water_map.h"
+#include "yapf/yapf.h"
+#include "date.h"
+#include "newgrf_sound.h"
+
+#include "table/bridge_land.h"
+
+const Bridge orig_bridge[] = {
+/*
+	     year of availablity
+	     |  minimum length
+	     |  |   maximum length
+	     |  |   |    price
+	     |  |   |    |    maximum speed
+	     |  |   |    |    |  sprite to use in GUI                string with description
+	     |  |   |    |    |  |                                   |                            */
+	{    0, 0, 16,  80,  32, 0xA24                             , STR_5012_WOODEN             , NULL, 0 },
+	{    0, 0,  2, 112,  48, 0xA26 | PALETTE_TO_STRUCT_RED     , STR_5013_CONCRETE           , NULL, 0 },
+	{ 1930, 0,  5, 144,  64, 0xA25                             , STR_500F_GIRDER_STEEL       , NULL, 0 },
+	{    0, 2, 10, 168,  80, 0xA22 | PALETTE_TO_STRUCT_CONCRETE, STR_5011_SUSPENSION_CONCRETE, NULL, 0 },
+	{ 1930, 3, 16, 185,  96, 0xA22                             , STR_500E_SUSPENSION_STEEL   , NULL, 0 },
+	{ 1930, 3, 16, 192, 112, 0xA22 | PALETTE_TO_STRUCT_YELLOW  , STR_500E_SUSPENSION_STEEL   , NULL, 0 },
+	{ 1930, 3,  7, 224, 160, 0xA23                             , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
+	{ 1930, 3,  8, 232, 208, 0xA23 | PALETTE_TO_STRUCT_BROWN   , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
+	{ 1930, 3,  9, 248, 240, 0xA23 | PALETTE_TO_STRUCT_RED     , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
+	{ 1930, 0,  2, 240, 256, 0xA27                             , STR_500F_GIRDER_STEEL       , NULL, 0 },
+	{ 1995, 2, 16, 255, 320, 0xA28                             , STR_5014_TUBULAR_STEEL      , NULL, 0 },
+	{ 2005, 2, 32, 380, 512, 0xA28 | PALETTE_TO_STRUCT_YELLOW  , STR_5014_TUBULAR_STEEL      , NULL, 0 },
+	{ 2010, 2, 32, 510, 608, 0xA28 | PALETTE_TO_STRUCT_GREY    , STR_BRIDGE_TUBULAR_SILICON  , NULL, 0 }
+};
+
+Bridge _bridge[MAX_BRIDGES];
+
+
+// calculate the price factor for building a long bridge.
+// basically the cost delta is 1,1, 1, 2,2, 3,3,3, 4,4,4,4, 5,5,5,5,5, 6,6,6,6,6,6,  7,7,7,7,7,7,7,  8,8,8,8,8,8,8,8,
+int CalcBridgeLenCostFactor(int x)
+{
+	int n;
+	int r;
+
+	if (x < 2) return x;
+	x -= 2;
+	for (n = 0, r = 2;; n++) {
+		if (x <= n) return r + x * n;
+		r += n * n;
+		x -= n;
+	}
+}
+
+#define M(x) (1 << (x))
+enum {
+	// foundation, whole tile is leveled up --> 3 corners raised
+	BRIDGE_FULL_LEVELED_FOUNDATION = M(SLOPE_WSE) | M(SLOPE_NWS) | M(SLOPE_ENW) | M(SLOPE_SEN),
+	// foundation, tile is partly leveled up --> 1 corner raised
+	BRIDGE_PARTLY_LEVELED_FOUNDATION = M(SLOPE_W) | M(SLOPE_S) | M(SLOPE_E) | M(SLOPE_N),
+	// no foundations (X,Y direction)
+	BRIDGE_NO_FOUNDATION = M(SLOPE_FLAT) | M(SLOPE_SW) | M(SLOPE_SE) | M(SLOPE_NW) | M(SLOPE_NE),
+	BRIDGE_HORZ_RAMP = (BRIDGE_PARTLY_LEVELED_FOUNDATION | BRIDGE_NO_FOUNDATION) & ~M(SLOPE_FLAT)
+};
+#undef M
+
+static inline const PalSpriteID *GetBridgeSpriteTable(int index, byte table)
+{
+	const Bridge *bridge = &_bridge[index];
+	assert(table < 7);
+	if (bridge->sprite_table == NULL || bridge->sprite_table[table] == NULL) {
+		return _bridge_sprite_table[index][table];
+	} else {
+		return bridge->sprite_table[table];
+	}
+}
+
+static inline byte GetBridgeFlags(int index) { return _bridge[index].flags;}
+
+
+/** Check the slope at the bridge ramps in three easy steps:
+ * - valid slopes without foundation
+ * - valid slopes with foundation
+ * - rest is invalid
+ */
+#define M(x) (1 << (x))
+static int32 CheckBridgeSlopeNorth(Axis axis, Slope tileh)
+{
+	uint32 valid;
+
+	valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_NE) : M(SLOPE_NW));
+	if (HASBIT(valid, tileh)) return 0;
+
+	valid =
+		BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_N) | M(SLOPE_STEEP_N) |
+		(axis == AXIS_X ? M(SLOPE_E) | M(SLOPE_STEEP_E) : M(SLOPE_W) | M(SLOPE_STEEP_W));
+	if (HASBIT(valid, tileh)) return _price.terraform;
+
+	return CMD_ERROR;
+}
+
+static int32 CheckBridgeSlopeSouth(Axis axis, Slope tileh)
+{
+	uint32 valid;
+
+	valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_SW) : M(SLOPE_SE));
+	if (HASBIT(valid, tileh)) return 0;
+
+	valid =
+		BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_S) | M(SLOPE_STEEP_S) |
+		(axis == AXIS_X ? M(SLOPE_W) | M(SLOPE_STEEP_W) : M(SLOPE_E) | M(SLOPE_STEEP_E));
+	if (HASBIT(valid, tileh)) return _price.terraform;
+
+	return CMD_ERROR;
+}
+#undef M
+
+
+uint32 GetBridgeLength(TileIndex begin, TileIndex end)
+{
+	int x1 = TileX(begin);
+	int y1 = TileY(begin);
+	int x2 = TileX(end);
+	int y2 = TileY(end);
+
+	return abs(x2 + y2 - x1 - y1) - 1;
+}
+
+bool CheckBridge_Stuff(byte bridge_type, uint bridge_len)
+{
+	const Bridge *b = &_bridge[bridge_type];
+	uint max; // max possible length of a bridge (with patch 100)
+
+	if (bridge_type >= MAX_BRIDGES) return false;
+	if (b->avail_year > _cur_year) return false;
+
+	max = b->max_length;
+	if (max >= 16 && _patches.longbridges) max = 100;
+
+	return b->min_length <= bridge_len && bridge_len <= max;
+}
+
+/** Build a Bridge
+ * @param end_tile end tile
+ * @param p1 packed start tile coords (~ dx)
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit 0- 7) - bridge type (hi bh)
+ * - p2 = (bit 8-..) - rail type. bit15 ((x>>8)&0x80) means road bridge.
+ */
+int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	int bridge_type;
+	TransportType transport;
+	RailType railtype;
+	uint x;
+	uint y;
+	uint sx;
+	uint sy;
+	TileIndex tile_start;
+	TileIndex tile_end;
+	Slope tileh_start;
+	Slope tileh_end;
+	uint z_start;
+	uint z_end;
+	TileIndex tile;
+	TileIndexDiff delta;
+	uint bridge_len;
+	Axis direction;
+	int32 cost, terraformcost, ret;
+	bool allow_on_slopes;
+
+	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
+
+	/* unpack parameters */
+	bridge_type = GB(p2, 0, 8);
+
+	if (p1 >= MapSize()) return CMD_ERROR;
+
+	// type of bridge
+	if (HASBIT(p2, 15)) {
+		railtype = 0;
+		transport = TRANSPORT_ROAD;
+	} else {
+		if (!ValParamRailtype(GB(p2, 8, 8))) return CMD_ERROR;
+		railtype = GB(p2, 8, 8);
+		transport = TRANSPORT_RAIL;
+	}
+
+	x = TileX(end_tile);
+	y = TileY(end_tile);
+	sx = TileX(p1);
+	sy = TileY(p1);
+
+	/* check if valid, and make sure that (x,y) are smaller than (sx,sy) */
+	if (x == sx) {
+		if (y == sy) return_cmd_error(STR_5008_CANNOT_START_AND_END_ON);
+		direction = AXIS_Y;
+		if (y > sy) uintswap(y,sy);
+	} else if (y == sy) {
+		direction = AXIS_X;
+		if (x > sx) uintswap(x,sx);
+	} else {
+		return_cmd_error(STR_500A_START_AND_END_MUST_BE_IN);
+	}
+
+	/* set and test bridge length, availability */
+	bridge_len = sx + sy - x - y - 1;
+	if (!CheckBridge_Stuff(bridge_type, bridge_len)) return_cmd_error(STR_5015_CAN_T_BUILD_BRIDGE_HERE);
+
+	/* retrieve landscape height and ensure it's on land */
+	tile_start = TileXY(x, y);
+	tile_end = TileXY(sx, sy);
+	if (IsClearWaterTile(tile_start) || IsClearWaterTile(tile_end)) {
+		return_cmd_error(STR_02A0_ENDS_OF_BRIDGE_MUST_BOTH);
+	}
+
+	tileh_start = GetTileSlope(tile_start, &z_start);
+	tileh_end = GetTileSlope(tile_end, &z_end);
+
+	if (IsSteepSlope(tileh_start)) z_start += TILE_HEIGHT;
+	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_start)) {
+		z_start += TILE_HEIGHT;
+		tileh_start = SLOPE_FLAT;
+	}
+
+	if (IsSteepSlope(tileh_end)) z_end += TILE_HEIGHT;
+	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_end)) {
+		z_end += TILE_HEIGHT;
+		tileh_end = SLOPE_FLAT;
+	}
+
+	if (z_start != z_end) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
+
+	// Towns are not allowed to use bridges on slopes.
+	allow_on_slopes = (!_is_old_ai_player
+	                   && _current_player != OWNER_TOWN && _patches.build_on_slopes);
+
+	/* Try and clear the start landscape */
+
+	ret = DoCommand(tile_start, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+	if (CmdFailed(ret)) return ret;
+	cost = ret;
+
+	terraformcost = CheckBridgeSlopeNorth(direction, tileh_start);
+	if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
+		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
+	cost += terraformcost;
+
+	/* Try and clear the end landscape */
+
+	ret = DoCommand(tile_end, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+	if (CmdFailed(ret)) return ret;
+	cost += ret;
+
+	// false - end tile slope check
+	terraformcost = CheckBridgeSlopeSouth(direction, tileh_end);
+	if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
+		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
+	cost += terraformcost;
+
+	{
+		TileIndex Heads[] = {tile_start, tile_end};
+		int i;
+
+		for (i = 0; i < 2; i++) {
+			if (MayHaveBridgeAbove(Heads[i])) {
+				if (IsBridgeAbove(Heads[i])) {
+					TileIndex north_head = GetNorthernBridgeEnd(Heads[i]);
+
+					if (direction == GetBridgeAxis(Heads[i])) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+
+					if (z_start + TILE_HEIGHT == GetBridgeHeight(north_head)) {
+						return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+					}
+				}
+			}
+		}
+	}
+
+	/* do the drill? */
+	if (flags & DC_EXEC) {
+		DiagDirection dir = AxisToDiagDir(direction);
+
+		if (transport == TRANSPORT_RAIL) {
+			MakeRailBridgeRamp(tile_start, _current_player, bridge_type, dir, railtype);
+			MakeRailBridgeRamp(tile_end,   _current_player, bridge_type, ReverseDiagDir(dir), railtype);
+		} else {
+			MakeRoadBridgeRamp(tile_start, _current_player, bridge_type, dir);
+			MakeRoadBridgeRamp(tile_end,   _current_player, bridge_type, ReverseDiagDir(dir));
+		}
+		MarkTileDirtyByTile(tile_start);
+		MarkTileDirtyByTile(tile_end);
+	}
+
+	delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
+	for (tile = tile_start + delta; tile != tile_end; tile += delta) {
+		uint z;
+
+		if (GetTileSlope(tile, &z) != SLOPE_FLAT && z >= z_start) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
+
+		if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
+			/* Disallow crossing bridges for the time being */
+			return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+		}
+
+		switch (GetTileType(tile)) {
+			case MP_WATER:
+				if (!EnsureNoVehicle(tile)) return_cmd_error(STR_980E_SHIP_IN_THE_WAY);
+				if (!IsWater(tile) && !IsCoast(tile)) goto not_valid_below;
+				break;
+
+			case MP_RAILWAY:
+				if (!IsPlainRailTile(tile)) goto not_valid_below;
+				break;
+
+			case MP_STREET:
+				if (GetRoadTileType(tile) == ROAD_TILE_DEPOT) goto not_valid_below;
+				break;
+
+			case MP_TUNNEL:
+				break;
+
+			case MP_STREET_BRIDGE:
+			case MP_RAILWAY_BRIDGE:
+				if (direction == DiagDirToAxis(GetBridgeRampDirection(tile))) goto not_valid_below;
+				if (z_start < GetBridgeHeight(tile)) goto not_valid_below;
+				break;
+
+			case MP_UNMOVABLE:
+				if (!IsOwnedLand(tile)) goto not_valid_below;
+				break;
+
+			case MP_CLEAR:
+				if (IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+				break;
+
+			default:
+not_valid_below:;
+				/* try and clear the middle landscape */
+				ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+				if (CmdFailed(ret)) return ret;
+				cost += ret;
+				break;
+		}
+
+		if (flags & DC_EXEC) {
+			SetBridgeMiddle(tile, direction);
+			MarkTileDirtyByTile(tile);
+		}
+	}
+
+	SetSignalsOnBothDir(tile_start, AxisToTrack(direction));
+	YapfNotifyTrackLayoutChange(tile_start, AxisToTrack(direction));
+
+	/* for human player that builds the bridge he gets a selection to choose from bridges (DC_QUERY_COST)
+	 * It's unnecessary to execute this command every time for every bridge. So it is done only
+	 * and cost is computed in "bridge_gui.c". For AI, Towns this has to be of course calculated
+	 */
+	if (!(flags & DC_QUERY_COST)) {
+		const Bridge *b = &_bridge[bridge_type];
+
+		bridge_len += 2; // begin and end tiles/ramps
+
+		if (IsValidPlayer(_current_player) && !_is_old_ai_player)
+			bridge_len = CalcBridgeLenCostFactor(bridge_len);
+
+		cost += (int64)bridge_len * _price.build_bridge * b->price >> 8;
+	}
+
+	return cost;
+}
+
+
+/** Build Tunnel.
+ * @param tile start tile of tunnel
+ * @param p1 railtype, 0x200 for road tunnel
+ * @param p2 unused
+ */
+int32 CmdBuildTunnel(TileIndex start_tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	TileIndexDiff delta;
+	TileIndex end_tile;
+	DiagDirection direction;
+	Slope start_tileh;
+	Slope end_tileh;
+	uint start_z;
+	uint end_z;
+	int32 cost;
+	int32 ret;
+
+	_build_tunnel_endtile = 0;
+
+	if (p1 != 0x200 && !ValParamRailtype(p1)) return CMD_ERROR;
+
+	start_tileh = GetTileSlope(start_tile, &start_z);
+
+	switch (start_tileh) {
+		case SLOPE_SW: direction = DIAGDIR_SW; break;
+		case SLOPE_SE: direction = DIAGDIR_SE; break;
+		case SLOPE_NW: direction = DIAGDIR_NW; break;
+		case SLOPE_NE: direction = DIAGDIR_NE; break;
+		default: return_cmd_error(STR_500B_SITE_UNSUITABLE_FOR_TUNNEL);
+	}
+
+	ret = DoCommand(start_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+	if (CmdFailed(ret)) return ret;
+
+	/* XXX - do NOT change 'ret' in the loop, as it is used as the price
+	 * for the clearing of the entrance of the tunnel. Assigning it to
+	 * cost before the loop will yield different costs depending on start-
+	 * position, because of increased-cost-by-length: 'cost += cost >> 3' */
+	cost = 0;
+	delta = TileOffsByDiagDir(direction);
+	end_tile = start_tile;
+	for (;;) {
+		end_tile += delta;
+		end_tileh = GetTileSlope(end_tile, &end_z);
+
+		if (start_z == end_z) break;
+
+		if (!_cheats.crossing_tunnels.value && IsTunnelInWay(end_tile, start_z)) {
+			return_cmd_error(STR_5003_ANOTHER_TUNNEL_IN_THE_WAY);
+		}
+
+		cost += _price.build_tunnel;
+		cost += cost >> 3; // add a multiplier for longer tunnels
+		if (cost >= 400000000) cost = 400000000;
+	}
+
+	/* Add the cost of the entrance */
+	cost += _price.build_tunnel + ret;
+
+	// if the command fails from here on we want the end tile to be highlighted
+	_build_tunnel_endtile = end_tile;
+
+	// slope of end tile must be complementary to the slope of the start tile
+	if (end_tileh != ComplementSlope(start_tileh)) {
+		ret = DoCommand(end_tile, end_tileh & start_tileh, 0, flags, CMD_TERRAFORM_LAND);
+		if (CmdFailed(ret)) return_cmd_error(STR_5005_UNABLE_TO_EXCAVATE_LAND);
+	} else {
+		ret = DoCommand(end_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+		if (CmdFailed(ret)) return ret;
+	}
+	cost += _price.build_tunnel + ret;
+
+	if (flags & DC_EXEC) {
+		if (GB(p1, 9, 1) == TRANSPORT_RAIL) {
+			MakeRailTunnel(start_tile, _current_player, direction,                 GB(p1, 0, 4));
+			MakeRailTunnel(end_tile,   _current_player, ReverseDiagDir(direction), GB(p1, 0, 4));
+			UpdateSignalsOnSegment(start_tile, direction);
+			YapfNotifyTrackLayoutChange(start_tile, AxisToTrack(DiagDirToAxis(direction)));
+		} else {
+			MakeRoadTunnel(start_tile, _current_player, direction);
+			MakeRoadTunnel(end_tile,   _current_player, ReverseDiagDir(direction));
+		}
+	}
+
+	return cost;
+}
+
+TileIndex CheckTunnelBusy(TileIndex tile, uint *length)
+{
+	uint z = GetTileZ(tile);
+	DiagDirection dir = GetTunnelDirection(tile);
+	TileIndexDiff delta = TileOffsByDiagDir(dir);
+	uint len = 0;
+	TileIndex starttile = tile;
+	Vehicle *v;
+
+	do {
+		tile += delta;
+		len++;
+	} while (
+		!IsTunnelTile(tile) ||
+		ReverseDiagDir(GetTunnelDirection(tile)) != dir ||
+		GetTileZ(tile) != z
+	);
+
+	v = FindVehicleBetween(starttile, tile, z);
+	if (v != NULL) {
+		_error_message = v->type == VEH_Train ?
+			STR_5000_TRAIN_IN_TUNNEL : STR_5001_ROAD_VEHICLE_IN_TUNNEL;
+		return INVALID_TILE;
+	}
+
+	if (length != NULL) *length = len;
+	return tile;
+}
+
+static inline bool CheckAllowRemoveTunnelBridge(TileIndex tile)
+{
+	/* Floods can remove anything as well as the scenario editor */
+	if (_current_player == OWNER_WATER || _game_mode == GM_EDITOR) return true;
+	/* Obviously if the bridge/tunnel belongs to us, or no-one, we can remove it */
+	if (CheckTileOwnership(tile) || IsTileOwner(tile, OWNER_NONE)) return true;
+	/* Otherwise we can only remove town-owned stuff with extra patch-settings, or cheat */
+	if (IsTileOwner(tile, OWNER_TOWN) && (_patches.extra_dynamite || _cheats.magic_bulldozer.value)) return true;
+	return false;
+}
+
+static int32 DoClearTunnel(TileIndex tile, uint32 flags)
+{
+	Town *t = NULL;
+	TileIndex endtile;
+	uint length;
+
+	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
+
+	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
+
+	endtile = CheckTunnelBusy(tile, &length);
+	if (endtile == INVALID_TILE) return CMD_ERROR;
+
+	_build_tunnel_endtile = endtile;
+
+	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
+		t = ClosestTownFromTile(tile, (uint)-1); // town penalty rating
+
+		/* Check if you are allowed to remove the tunnel owned by a town
+		 * Removal depends on difficulty settings */
+		if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
+			SetDParam(0, t->index);
+			return_cmd_error(STR_2009_LOCAL_AUTHORITY_REFUSES);
+		}
+	}
+
+	if (flags & DC_EXEC) {
+		// We first need to request the direction before calling DoClearSquare
+		//  else the direction is always 0.. dah!! ;)
+		DiagDirection dir = GetTunnelDirection(tile);
+		Track track;
+
+		// Adjust the town's player rating. Do this before removing the tile owner info.
+		if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR)
+			ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM);
+
+		DoClearSquare(tile);
+		DoClearSquare(endtile);
+		UpdateSignalsOnSegment(tile, ReverseDiagDir(dir));
+		UpdateSignalsOnSegment(endtile, dir);
+		track = AxisToTrack(DiagDirToAxis(dir));
+		YapfNotifyTrackLayoutChange(tile, track);
+		YapfNotifyTrackLayoutChange(endtile, track);
+	}
+	return _price.clear_tunnel * (length + 1);
+}
+
+
+static bool IsVehicleOnBridge(TileIndex starttile, TileIndex endtile, uint z)
+{
+	const Vehicle *v;
+	FOR_ALL_VEHICLES(v) {
+		if ((v->tile == starttile || v->tile == endtile) && v->z_pos == z) {
+			_error_message = VehicleInTheWayErrMsg(v);
+			return true;
+		}
+	}
+	return false;
+}
+
+static int32 DoClearBridge(TileIndex tile, uint32 flags)
+{
+	DiagDirection direction;
+	TileIndexDiff delta;
+	TileIndex endtile;
+	Town *t = NULL;
+
+	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
+
+	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
+
+	endtile = GetOtherBridgeEnd(tile);
+
+	if (!EnsureNoVehicle(tile) ||
+			!EnsureNoVehicle(endtile) ||
+			IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
+		return CMD_ERROR;
+	}
+
+	direction = GetBridgeRampDirection(tile);
+	delta = TileOffsByDiagDir(direction);
+
+	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
+		t = ClosestTownFromTile(tile, (uint)-1); // town penalty rating
+
+		/* Check if you are allowed to remove the bridge owned by a town
+		 * Removal depends on difficulty settings */
+		if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
+			SetDParam(0, t->index);
+			return_cmd_error(STR_2009_LOCAL_AUTHORITY_REFUSES);
+		}
+	}
+
+	if (flags & DC_EXEC) {
+		TileIndex c;
+		Track track;
+
+		//checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
+		// you have a "Poor" (0) town rating
+		if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR)
+			ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM);
+
+		DoClearSquare(tile);
+		DoClearSquare(endtile);
+		for (c = tile + delta; c != endtile; c += delta) {
+				ClearBridgeMiddle(c);
+			MarkTileDirtyByTile(c);
+		}
+
+		UpdateSignalsOnSegment(tile, ReverseDiagDir(direction));
+		UpdateSignalsOnSegment(endtile, direction);
+		track = AxisToTrack(DiagDirToAxis(direction));
+		YapfNotifyTrackLayoutChange(tile, track);
+		YapfNotifyTrackLayoutChange(endtile, track);
+	}
+
+	return (DistanceManhattan(tile, endtile) + 1) * _price.clear_bridge;
+}
+
+static int32 ClearTile_Tunnel(TileIndex tile, byte flags)
+{
+	assert(IsTunnelTile(tile));
+	if (flags & DC_AUTO) return_cmd_error(STR_5006_MUST_DEMOLISH_TUNNEL_FIRST);
+	return DoClearTunnel(tile, flags);
+}
+
+static int32 ClearTile_Bridge(TileIndex tile, byte flags)
+{
+	assert(IsBridgeTile(tile));
+	if (flags & DC_AUTO) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+	return DoClearBridge(tile, flags);
+}
+
+int32 DoConvertTunnelBridgeRail(TileIndex tile, RailType totype, bool exec)
+{
+	TileIndex endtile;
+
+	if (IsTunnelTile(tile) && GetTunnelTransportType(tile) == TRANSPORT_RAIL) {
+		uint length;
+
+		if (!CheckTileOwnership(tile)) return CMD_ERROR;
+
+		if (GetRailType(tile) == totype) return CMD_ERROR;
+
+		// 'hidden' elrails can't be downgraded to normal rail when elrails are disabled
+		if (_patches.disable_elrails && totype == RAILTYPE_RAIL && GetRailType(tile) == RAILTYPE_ELECTRIC) return CMD_ERROR;
+
+		endtile = CheckTunnelBusy(tile, &length);
+		if (endtile == INVALID_TILE) return CMD_ERROR;
+
+		if (exec) {
+			Track track;
+			SetRailType(tile, totype);
+			SetRailType(endtile, totype);
+			MarkTileDirtyByTile(tile);
+			MarkTileDirtyByTile(endtile);
+
+			track = AxisToTrack(DiagDirToAxis(GetTunnelDirection(tile)));
+			YapfNotifyTrackLayoutChange(tile, track);
+			YapfNotifyTrackLayoutChange(endtile, track);
+		}
+		return (length + 1) * (_price.build_rail >> 1);
+	} else if (IsBridgeTile(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
+
+		if (!CheckTileOwnership(tile)) return CMD_ERROR;
+
+		endtile = GetOtherBridgeEnd(tile);
+
+		if (!EnsureNoVehicle(tile) ||
+				!EnsureNoVehicle(endtile) ||
+				IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
+			return CMD_ERROR;
+		}
+
+		if (GetRailType(tile) == totype) return CMD_ERROR;
+
+		if (exec) {
+			TileIndexDiff delta;
+			Track track;
+
+			SetRailType(tile, totype);
+			SetRailType(endtile, totype);
+			MarkTileDirtyByTile(tile);
+			MarkTileDirtyByTile(endtile);
+
+			track = AxisToTrack(DiagDirToAxis(GetBridgeRampDirection(tile)));
+			YapfNotifyTrackLayoutChange(tile, track);
+			YapfNotifyTrackLayoutChange(endtile, track);
+
+			delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));
+			for (tile += delta; tile != endtile; tile += delta) {
+				MarkTileDirtyByTile(tile); // TODO encapsulate this into a function
+			}
+		}
+
+		return (DistanceManhattan(tile, endtile) + 1) * (_price.build_rail >> 1);
+	} else {
+		return CMD_ERROR;
+	}
+}
+
+
+static void DrawBridgePillars(PalSpriteID image, const TileInfo* ti, Axis axis, uint type, int x, int y, int z)
+{
+	if (image != 0) {
+		bool drawfarpillar = !HASBIT(GetBridgeFlags(type), 0);
+		int back_height, front_height;
+		int i = z;
+		const byte *p;
+
+		static const byte _tileh_bits[4][8] = {
+			{ 2, 1, 8, 4,  16,  2, 0, 9 },
+			{ 1, 8, 4, 2,   2, 16, 9, 0 },
+			{ 4, 8, 1, 2,  16,  2, 0, 9 },
+			{ 2, 4, 8, 1,   2, 16, 9, 0 }
+		};
+
+		if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+
+		p = _tileh_bits[(image & 1) * 2 + (axis == AXIS_X ? 0 : 1)];
+		front_height = ti->z + (ti->tileh & p[0] ? TILE_HEIGHT : 0);
+		back_height  = ti->z + (ti->tileh & p[1] ? TILE_HEIGHT : 0);
+
+		if (IsSteepSlope(ti->tileh)) {
+			if (!(ti->tileh & p[2])) front_height += TILE_HEIGHT;
+			if (!(ti->tileh & p[3])) back_height  += TILE_HEIGHT;
+		}
+
+		for (; z >= front_height || z >= back_height; z -= TILE_HEIGHT) {
+			/* HACK set height of the BB of pillars to 1, because the origin of the
+			 * sprites is at the top
+			 */
+			if (z >= front_height) { // front facing pillar
+				AddSortableSpriteToDraw(image, x, y, p[4], p[5], 1, z);
+			}
+
+			if (drawfarpillar && z >= back_height && z < i - TILE_HEIGHT) { // back facing pillar
+				AddSortableSpriteToDraw(image, x - p[6], y - p[7], p[4], p[5], 1, z);
+			}
+		}
+	}
+}
+
+uint GetBridgeFoundation(Slope tileh, Axis axis)
+{
+	uint i;
+
+	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) return tileh;
+
+	// inclined sloped building
+	switch (tileh) {
+		case SLOPE_W:
+		case SLOPE_STEEP_W: i = 0; break;
+		case SLOPE_S:
+		case SLOPE_STEEP_S: i = 2; break;
+		case SLOPE_E:
+		case SLOPE_STEEP_E: i = 4; break;
+		case SLOPE_N:
+		case SLOPE_STEEP_N: i = 6; break;
+		default: return 0;
+	}
+	if (axis != AXIS_X) ++i;
+	return i + 15;
+}
+
+/**
+ * Draws a tunnel tile.
+ * Please note that in this code, "roads" are treated as railtype 1, whilst the real railtypes are 0, 2 and 3
+ */
+static void DrawTile_Tunnel(TileInfo *ti)
+{
+	uint32 image;
+
+	if (GetTunnelTransportType(ti->tile) == TRANSPORT_RAIL) {
+		image = GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.tunnel;
+	} else {
+		image = SPR_TUNNEL_ENTRY_REAR_ROAD;
+	}
+
+	if (HasTunnelSnowOrDesert(ti->tile)) image += 32;
+
+	image += GetTunnelDirection(ti->tile) * 2;
+	DrawGroundSprite(image);
+	if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+	AddSortableSpriteToDraw(image+1, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, 1, 1, 8, (byte)ti->z);
+	DrawBridgeMiddle(ti);
+}
+
+/**
+ * Draws a bridge tile.
+ * base_offset is where the sprite selection comes into play
+ * and it works a bit like a bitmask.<p> For bridge heads:
+ * <ul><li>Bit 0: direction</li>
+ * <li>Bit 1: northern or southern heads</li>
+ * <li>Bit 2: Set if the bridge head is sloped</li>
+ * <li>Bit 3 and more: Railtype Specific subset</li>
+ * </ul>
+ * Please note that in this code, "roads" are treated as railtype 1, whilst the real railtypes are 0, 2 and 3
+ */
+static void DrawTile_Bridge(TileInfo *ti)
+{
+	uint32 image;
+
+	int base_offset;
+	bool ice = HasBridgeSnowOrDesert(ti->tile);
+
+	if (GetBridgeTransportType(ti->tile) == TRANSPORT_RAIL) {
+		base_offset = GetRailTypeInfo(GetRailType(ti->tile))->bridge_offset;
+		assert(base_offset != 8); /* This one is used for roads */
+	} else {
+		base_offset = 8;
+	}
+
+	/* as the lower 3 bits are used for other stuff, make sure they are clear */
+	assert( (base_offset & 0x07) == 0x00);
+
+	if (!HASBIT(BRIDGE_NO_FOUNDATION, ti->tileh)) {
+		int f = GetBridgeFoundation(ti->tileh, DiagDirToAxis(GetBridgeRampDirection(ti->tile)));
+		if (f != 0) DrawFoundation(ti, f);
+	}
+
+	// HACK Wizardry to convert the bridge ramp direction into a sprite offset
+	base_offset += (6 - GetBridgeRampDirection(ti->tile)) % 4;
+
+	if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
+
+	/* Table number 6 always refers to the bridge heads for any bridge type */
+	image = GetBridgeSpriteTable(GetBridgeType(ti->tile), 6)[base_offset];
+
+	if (!ice) {
+		DrawClearLandTile(ti, 3);
+	} else {
+		DrawGroundSprite(SPR_FLAT_SNOWY_TILE + _tileh_to_sprite[ti->tileh]);
+	}
+
+	if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+	// draw ramp
+	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+	/* HACK set the height of the BB of a sloped ramp to 1 so a vehicle on
+	 * it doesn't disappear behind it
+	 */
+	AddSortableSpriteToDraw(
+		image, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 1 : 8, ti->z
+	);
+
+	DrawBridgeMiddle(ti);
+}
+
+
+/** Compute bridge piece. Computes the bridge piece to display depending on the position inside the bridge.
+ * bridges pieces sequence (middle parts)
+ * bridge len 1: 0
+ * bridge len 2: 0 1
+ * bridge len 3: 0 4 1
+ * bridge len 4: 0 2 3 1
+ * bridge len 5: 0 2 5 3 1
+ * bridge len 6: 0 2 3 2 3 1
+ * bridge len 7: 0 2 3 4 2 3 1
+ * #0 - always as first, #1 - always as last (if len>1)
+ * #2,#3 are to pair in order
+ * for odd bridges: #5 is going in the bridge middle if on even position, #4 on odd (counting from 0)
+ * @param north Northernmost tile of bridge
+ * @param south Southernmost tile of bridge
+ * @return Index of bridge piece
+ */
+static uint CalcBridgePiece(uint north, uint south)
+{
+	if (north == 1) {
+		return 0;
+	} else if (south == 1) {
+		return 1;
+	} else if (north < south) {
+		return north & 1 ? 3 : 2;
+	} else if (north > south) {
+		return south & 1 ? 2 : 3;
+	} else {
+		return north & 1 ? 5 : 4;
+	}
+}
+
+
+void DrawBridgeMiddle(const TileInfo* ti)
+{
+	const PalSpriteID* b;
+	PalSpriteID image;
+	uint base_offset;
+	TileIndex rampnorth;
+	TileIndex rampsouth;
+	Axis axis;
+	uint piece;
+	uint type;
+	int x;
+	int y;
+	uint z;
+
+	if (!IsBridgeAbove(ti->tile)) return;
+
+	rampnorth = GetNorthernBridgeEnd(ti->tile);
+	rampsouth = GetSouthernBridgeEnd(ti->tile);
+
+	axis = GetBridgeAxis(ti->tile);
+	piece = CalcBridgePiece(
+		DistanceManhattan(ti->tile, rampnorth),
+		DistanceManhattan(ti->tile, rampsouth)
+	);
+	type = GetBridgeType(rampsouth);
+
+	if (GetBridgeTransportType(rampsouth) == TRANSPORT_RAIL) {
+		base_offset = GetRailTypeInfo(GetRailType(rampsouth))->bridge_offset;
+	} else {
+		base_offset = 8;
+	}
+
+	b = base_offset + GetBridgeSpriteTable(type, piece);
+	if (axis != AXIS_X) b += 4;
+
+	x = ti->x;
+	y = ti->y;
+	z = GetBridgeHeight(rampsouth) - 3;
+
+	image = b[0];
+	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+	if (axis == AXIS_X) {
+		AddSortableSpriteToDraw(image, x, y, 16, 11, 1, z);
+	} else {
+		AddSortableSpriteToDraw(image, x, y, 11, 16, 1, z);
+	}
+
+	image = b[1];
+	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+
+	// draw roof, the component of the bridge which is logically between the vehicle and the camera
+	if (axis == AXIS_X) {
+		y += 12;
+		if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 16, 1, 0x28, z);
+	} else {
+		x += 12;
+		if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 1, 16, 0x28, z);
+	}
+
+	if (GetRailType(rampsouth) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+	if (ti->z + 5 == z) {
+		// draw poles below for small bridges
+		image = b[2];
+		if (image != 0) {
+			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+			DrawGroundSpriteAt(image, x, y, z);
+		}
+	} else if (_patches.bridge_pillars) {
+		// draw pillars below for high bridges
+		DrawBridgePillars(b[2], ti, axis, type, x, y, z);
+	}
+}
+
+
+uint SetSpeedLimitOnBridge(Vehicle *v)
+{
+	uint bridge_speed;
+	if (v->vehstatus & VS_HIDDEN) return v->max_speed; /* in tunnel */
+
+	bridge_speed = _bridge[GetBridgeType(v->tile)].speed;
+
+	if (v->type == VEH_Road) bridge_speed *= 2; /* XXX give vehicles proper speeds */
+
+	if (v->cur_speed > bridge_speed) v->cur_speed = bridge_speed;
+	return bridge_speed;
+}
+
+
+/** Gets the absolute z coordinate of a point inside a tunnel tile
+ *  When we're on the track (that means between position 5 and 10)
+ *  on the coordinate perpendicular to the track it returns only the
+ *  base height of the tile (because the track is horizontal).
+ *  Outside this range (from 0 to 4 and from 11 to 15) it returns the
+ *  "true" Z coordinate of the tile by taking the slope into account
+ *  @param tile The index of the tile we are talking about
+ *  @param x Absolute or relative x coordinate
+ *  @param y Absolute or relative y coordinate
+ *  @return Absolute z coordinate
+ */
+static uint GetSlopeZ_Tunnel(TileIndex tile, uint x, uint y)
+{
+	uint z, pos;
+	Slope tileh = GetTileSlope(tile, &z);
+
+	x &= 0xF;
+	y &= 0xF;
+
+	pos = (DiagDirToAxis(GetTunnelDirection(tile)) == AXIS_X ? y : x);
+
+	// In the tunnel entrance?
+	if (5 <= pos && pos <= 10) return z;
+
+	return z + GetPartialZ(x, y, tileh);
+}
+
+/** Gets the absolute z coordinate of a point inside a bridge tile
+ *  When we're on the track (that means between position 5 and 10)
+ *  on the coordinate perpendicular to the track it returns the base
+ *  height of the ramp
+ *  Outside this range (from 0 to 4 and from 11 to 15) it returns the
+ *  "true" Z coordinate of the tile by taking the slope into account
+ *  @param tile The index of the tile we are talking about
+ *  @param x Absolute or relative x coordinate
+ *  @param y Absolute or relative y coordinate
+ *  @return Absolute z coordinate
+ */
+static uint GetSlopeZ_Bridge(TileIndex tile, uint x, uint y)
+{
+	uint z, pos;
+	Slope tileh = GetTileSlope(tile, &z);
+	DiagDirection dir = GetBridgeRampDirection(tile);
+
+	x &= 0xF;
+	y &= 0xF;
+
+	pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
+
+	// On the bridge ramp?
+	if (5 <= pos && pos <= 10) {
+		uint delta;
+
+		if (IsSteepSlope(tileh)) return z + TILE_HEIGHT * 2;
+
+		if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + TILE_HEIGHT;
+
+		if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += TILE_HEIGHT;
+		switch (dir) {
+			default: NOT_REACHED();
+			case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
+			case DIAGDIR_SE: delta = y / 2; break;
+			case DIAGDIR_SW: delta = x / 2; break;
+			case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
+		}
+		return z + 1 + delta;
+	} else {
+		uint f = GetBridgeFoundation(tileh, DiagDirToAxis(dir));
+
+		if (f != 0) {
+			if (IsSteepSlope(tileh)) {
+				z += TILE_HEIGHT;
+			} else if (f < 15) {
+				return z + TILE_HEIGHT;
+			}
+			tileh = _inclined_tileh[f - 15];
+		}
+	}
+	return z + GetPartialZ(x, y, tileh);
+}
+
+static Slope GetSlopeTileh_Tunnel(TileIndex tile, Slope tileh)
+{
+	return tileh;
+}
+
+static Slope GetSlopeTileh_Bridge(TileIndex tile, Slope tileh)
+{
+	if (HASBIT(BRIDGE_NO_FOUNDATION, tileh)) {
+		return tileh;
+	} else {
+		uint f = GetBridgeFoundation(tileh, DiagDirToAxis(GetBridgeRampDirection(tile)));
+
+		if (f == 0) return tileh;
+		if (f < 15) return SLOPE_FLAT;
+		return _inclined_tileh[f - 15];
+	}
+}
+
+static void GetAcceptedCargo_Tunnel(TileIndex tile, AcceptedCargo ac)
+{
+	/* not used */
+}
+
+static void GetAcceptedCargo_Bridge(TileIndex tile, AcceptedCargo ac)
+{
+	/* not used */
+}
+
+static const StringID _bridge_tile_str[(MAX_BRIDGES + 3) + (MAX_BRIDGES + 3)] = {
+	STR_501F_WOODEN_RAIL_BRIDGE,
+	STR_5020_CONCRETE_RAIL_BRIDGE,
+	STR_501C_STEEL_GIRDER_RAIL_BRIDGE,
+	STR_501E_REINFORCED_CONCRETE_SUSPENSION,
+	STR_501B_STEEL_SUSPENSION_RAIL_BRIDGE,
+	STR_501B_STEEL_SUSPENSION_RAIL_BRIDGE,
+	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+	STR_501C_STEEL_GIRDER_RAIL_BRIDGE,
+	STR_5027_TUBULAR_RAIL_BRIDGE,
+	STR_5027_TUBULAR_RAIL_BRIDGE,
+	STR_5027_TUBULAR_RAIL_BRIDGE,
+	0, 0, 0,
+
+	STR_5025_WOODEN_ROAD_BRIDGE,
+	STR_5026_CONCRETE_ROAD_BRIDGE,
+	STR_5022_STEEL_GIRDER_ROAD_BRIDGE,
+	STR_5024_REINFORCED_CONCRETE_SUSPENSION,
+	STR_5021_STEEL_SUSPENSION_ROAD_BRIDGE,
+	STR_5021_STEEL_SUSPENSION_ROAD_BRIDGE,
+	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+	STR_5022_STEEL_GIRDER_ROAD_BRIDGE,
+	STR_5028_TUBULAR_ROAD_BRIDGE,
+	STR_5028_TUBULAR_ROAD_BRIDGE,
+	STR_5028_TUBULAR_ROAD_BRIDGE,
+	0, 0, 0,
+};
+
+static void GetTileDesc_Tunnel(TileIndex tile, TileDesc *td)
+{
+	td->str = (GetTunnelTransportType(tile) == TRANSPORT_RAIL) ?  STR_5017_RAILROAD_TUNNEL : STR_5018_ROAD_TUNNEL;
+	td->owner = GetTileOwner(tile);
+}
+
+static void GetTileDesc_Bridge(TileIndex tile, TileDesc *td)
+{
+	td->str = _bridge_tile_str[GetBridgeTransportType(tile) << 4 | GetBridgeType(tile)];
+	td->owner = GetTileOwner(tile);
+}
+
+
+static void AnimateTile_Tunnel(TileIndex tile)
+{
+	/* not used */
+}
+
+static void AnimateTile_Bridge(TileIndex tile)
+{
+	/* not used */
+}
+
+static void TileLoop_Tunnel(TileIndex tile)
+{
+	bool snow_or_desert = HasTunnelSnowOrDesert(tile);
+	switch (_opt.landscape) {
+		case LT_HILLY:
+			if (snow_or_desert != (GetTileZ(tile) > _opt.snow_line)) {
+				SetTunnelSnowOrDesert(tile, !snow_or_desert);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+
+		case LT_DESERT:
+			if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
+				SetTunnelSnowOrDesert(tile, true);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+	}
+}
+
+static void TileLoop_Bridge(TileIndex tile)
+{
+	bool snow_or_desert = HasBridgeSnowOrDesert(tile);
+	switch (_opt.landscape) {
+		case LT_HILLY:
+			if (snow_or_desert != (GetTileZ(tile) > _opt.snow_line)) {
+				SetBridgeSnowOrDesert(tile, !snow_or_desert);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+
+		case LT_DESERT:
+			if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
+				SetBridgeSnowOrDesert(tile, true);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+	}
+}
+
+static void ClickTile_Tunnel(TileIndex tile)
+{
+	/* not used */
+}
+
+static void ClickTile_Bridge(TileIndex tile)
+{
+	/* not used */
+}
+
+
+static uint32 GetTileTrackStatus_Tunnel(TileIndex tile, TransportType mode)
+{
+	if (GetTunnelTransportType(tile) != mode) return 0;
+	return AxisToTrackBits(DiagDirToAxis(GetTunnelDirection(tile))) * 0x101;
+}
+
+static uint32 GetTileTrackStatus_Bridge(TileIndex tile, TransportType mode)
+{
+	if (GetBridgeTransportType(tile) != mode) return 0;
+	return AxisToTrackBits(DiagDirToAxis(GetBridgeRampDirection(tile))) * 0x101;
+}
+
+static void ChangeTileOwner_Tunnel(TileIndex tile, PlayerID old_player, PlayerID new_player)
+{
+	if (!IsTileOwner(tile, old_player)) return;
+
+	if (new_player != PLAYER_SPECTATOR) {
+		SetTileOwner(tile, new_player);
+	} else {
+		DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+	}
+}
+
+static void ChangeTileOwner_Bridge(TileIndex tile, PlayerID old_player, PlayerID new_player)
+{
+	if (!IsTileOwner(tile, old_player)) return;
+
+	if (new_player != PLAYER_SPECTATOR) {
+		SetTileOwner(tile, new_player);
+	} else {
+		DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+	}
+}
+
+
+static const byte _tunnel_fractcoord_1[4]    = {0x8E, 0x18, 0x81, 0xE8};
+static const byte _tunnel_fractcoord_2[4]    = {0x81, 0x98, 0x87, 0x38};
+static const byte _tunnel_fractcoord_3[4]    = {0x82, 0x88, 0x86, 0x48};
+static const byte _exit_tunnel_track[4]      = {1, 2, 1, 2};
+
+static const byte _road_exit_tunnel_state[4] = {8, 9, 0, 1};
+static const byte _road_exit_tunnel_frame[4] = {2, 7, 9, 4};
+
+static const byte _tunnel_fractcoord_4[4]    = {0x52, 0x85, 0x98, 0x29};
+static const byte _tunnel_fractcoord_5[4]    = {0x92, 0x89, 0x58, 0x25};
+static const byte _tunnel_fractcoord_6[4]    = {0x92, 0x89, 0x56, 0x45};
+static const byte _tunnel_fractcoord_7[4]    = {0x52, 0x85, 0x96, 0x49};
+
+static uint32 VehicleEnter_Tunnel(Vehicle *v, TileIndex tile, int x, int y)
+{
+	int z = GetSlopeZ(x, y) - v->z_pos;
+
+	byte fc;
+	DiagDirection dir;
+	DiagDirection vdir;
+
+	if (myabs(z) > 2) return 8;
+
+	if (v->type == VEH_Train) {
+		fc = (x & 0xF) + (y << 4);
+
+		dir = GetTunnelDirection(tile);
+		vdir = DirToDiagDir(v->direction);
+
+		if (v->u.rail.track != 0x40 && dir == vdir) {
+			if (IsFrontEngine(v) && fc == _tunnel_fractcoord_1[dir]) {
+				if (!PlayVehicleSound(v, VSE_TUNNEL) && v->spritenum < 4) {
+					SndPlayVehicleFx(SND_05_TRAIN_THROUGH_TUNNEL, v);
+				}
+				return 0;
+			}
+			if (fc == _tunnel_fractcoord_2[dir]) {
+				v->tile = tile;
+				v->u.rail.track = 0x40;
+				v->vehstatus |= VS_HIDDEN;
+				return 4;
+			}
+		}
+
+		if (dir == ReverseDiagDir(vdir) && fc == _tunnel_fractcoord_3[dir] && z == 0) {
+			/* We're at the tunnel exit ?? */
+			v->tile = tile;
+			v->u.rail.track = _exit_tunnel_track[dir];
+			assert(v->u.rail.track);
+			v->vehstatus &= ~VS_HIDDEN;
+			return 4;
+		}
+	} else if (v->type == VEH_Road) {
+		fc = (x & 0xF) + (y << 4);
+		dir = GetTunnelDirection(tile);
+		vdir = DirToDiagDir(v->direction);
+
+		// Enter tunnel?
+		if (v->u.road.state != 0xFF && dir == vdir) {
+			if (fc == _tunnel_fractcoord_4[dir] ||
+					fc == _tunnel_fractcoord_5[dir]) {
+				v->tile = tile;
+				v->u.road.state = 0xFF;
+				v->vehstatus |= VS_HIDDEN;
+				return 4;
+			} else {
+				return 0;
+			}
+		}
+
+		if (dir == ReverseDiagDir(vdir) && (
+					/* We're at the tunnel exit ?? */
+					fc == _tunnel_fractcoord_6[dir] ||
+					fc == _tunnel_fractcoord_7[dir]
+				) &&
+				z == 0) {
+			v->tile = tile;
+			v->u.road.state = _road_exit_tunnel_state[dir];
+			v->u.road.frame = _road_exit_tunnel_frame[dir];
+			v->vehstatus &= ~VS_HIDDEN;
+			return 4;
+		}
+	}
+	return 0;
+}
+
+static uint32 VehicleEnter_Bridge(Vehicle *v, TileIndex tile, int x, int y)
+{
+	int z = GetSlopeZ(x, y) - v->z_pos;
+
+	DiagDirection dir;
+
+	if (myabs(z) > 2) return 8;
+
+	if (v->type == VEH_Road || (v->type == VEH_Train && IsFrontEngine(v))) {
+		/* modify speed of vehicle */
+		uint16 spd = _bridge[GetBridgeType(tile)].speed;
+
+		if (v->type == VEH_Road) spd *= 2;
+		if (v->cur_speed > spd) v->cur_speed = spd;
+	}
+
+	dir = GetBridgeRampDirection(tile);
+	if (DirToDiagDir(v->direction) == dir) {
+		switch (dir) {
+			default: NOT_REACHED();
+			case DIAGDIR_NE: if ((x & 0xF) != 0)             return 0; break;
+			case DIAGDIR_SE: if ((y & 0xF) != TILE_SIZE - 1) return 0; break;
+			case DIAGDIR_SW: if ((x & 0xF) != TILE_SIZE - 1) return 0; break;
+			case DIAGDIR_NW: if ((y & 0xF) != 0)             return 0; break;
+		}
+		if (v->type == VEH_Train) {
+			v->u.rail.track = 0x40;
+			CLRBIT(v->u.rail.flags, VRF_GOINGUP);
+			CLRBIT(v->u.rail.flags, VRF_GOINGDOWN);
+		} else {
+			v->u.road.state = 0xFF;
+		}
+		return 4;
+	} else if (DirToDiagDir(v->direction) == ReverseDiagDir(dir)) {
+		v->tile = tile;
+		if (v->type == VEH_Train) {
+			if (v->u.rail.track == 0x40) {
+				v->u.rail.track = (DiagDirToAxis(dir) == AXIS_X ? 1 : 2);
+				return 4;
+			}
+		} else {
+			if (v->u.road.state == 0xFF) {
+				v->u.road.state = _road_exit_tunnel_state[dir];
+				v->u.road.frame = 0;
+				return 4;
+			}
+		}
+		return 0;
+	}
+	return 0;
+}
+
+const TileTypeProcs _tile_type_tunnel_procs = {
+	DrawTile_Tunnel,           /* draw_tile_proc */
+	GetSlopeZ_Tunnel,          /* get_slope_z_proc */
+	ClearTile_Tunnel,          /* clear_tile_proc */
+	GetAcceptedCargo_Tunnel,   /* get_accepted_cargo_proc */
+	GetTileDesc_Tunnel,        /* get_tile_desc_proc */
+	GetTileTrackStatus_Tunnel, /* get_tile_track_status_proc */
+	ClickTile_Tunnel,          /* click_tile_proc */
+	AnimateTile_Tunnel,        /* animate_tile_proc */
+	TileLoop_Tunnel,           /* tile_loop_clear */
+	ChangeTileOwner_Tunnel,    /* change_tile_owner_clear */
+	NULL,                            /* get_produced_cargo_proc */
+	VehicleEnter_Tunnel,       /* vehicle_enter_tile_proc */
+	GetSlopeTileh_Tunnel,      /* get_slope_tileh_proc */
+};
+
+const TileTypeProcs _tile_type_bridge_procs = {
+	DrawTile_Bridge,           /* draw_tile_proc */
+	GetSlopeZ_Bridge,          /* get_slope_z_proc */
+	ClearTile_Bridge,          /* clear_tile_proc */
+	GetAcceptedCargo_Bridge,   /* get_accepted_cargo_proc */
+	GetTileDesc_Bridge,        /* get_tile_desc_proc */
+	GetTileTrackStatus_Bridge, /* get_tile_track_status_proc */
+	ClickTile_Bridge,          /* click_tile_proc */
+	AnimateTile_Bridge,        /* animate_tile_proc */
+	TileLoop_Bridge,           /* tile_loop_clear */
+	ChangeTileOwner_Bridge,    /* change_tile_owner_clear */
+	NULL,                      /* get_produced_cargo_proc */
+	VehicleEnter_Bridge,       /* vehicle_enter_tile_proc */
+	GetSlopeTileh_Bridge,      /* get_slope_tileh_proc */
+};
diff -r 3e0dd1f014ca -r 04068f82afaa tunnelbridge_cmd.c
--- a/tunnelbridge_cmd.c	Fri Dec 29 11:03:39 2006 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1415 +0,0 @@
-/* $Id$ */
-
-/** @file tunnelbridge_cmd.c
- * This file deals with tunnels and bridges (non-gui stuff)
- * @todo seperate this file into two
- */
-
-#include "stdafx.h"
-#include "openttd.h"
-#include "bridge_map.h"
-#include "rail_map.h"
-#include "road_map.h"
-#include "table/sprites.h"
-#include "table/strings.h"
-#include "functions.h"
-#include "map.h"
-#include "tile.h"
-#include "tunnel_map.h"
-#include "unmovable_map.h"
-#include "vehicle.h"
-#include "viewport.h"
-#include "command.h"
-#include "player.h"
-#include "town.h"
-#include "sound.h"
-#include "variables.h"
-#include "bridge.h"
-#include "train.h"
-#include "water_map.h"
-#include "yapf/yapf.h"
-#include "date.h"
-#include "newgrf_sound.h"
-
-#include "table/bridge_land.h"
-
-const Bridge orig_bridge[] = {
-/*
-	     year of availablity
-	     |  minimum length
-	     |  |   maximum length
-	     |  |   |    price
-	     |  |   |    |    maximum speed
-	     |  |   |    |    |  sprite to use in GUI                string with description
-	     |  |   |    |    |  |                                   |                            */
-	{    0, 0, 16,  80,  32, 0xA24                             , STR_5012_WOODEN             , NULL, 0 },
-	{    0, 0,  2, 112,  48, 0xA26 | PALETTE_TO_STRUCT_RED     , STR_5013_CONCRETE           , NULL, 0 },
-	{ 1930, 0,  5, 144,  64, 0xA25                             , STR_500F_GIRDER_STEEL       , NULL, 0 },
-	{    0, 2, 10, 168,  80, 0xA22 | PALETTE_TO_STRUCT_CONCRETE, STR_5011_SUSPENSION_CONCRETE, NULL, 0 },
-	{ 1930, 3, 16, 185,  96, 0xA22                             , STR_500E_SUSPENSION_STEEL   , NULL, 0 },
-	{ 1930, 3, 16, 192, 112, 0xA22 | PALETTE_TO_STRUCT_YELLOW  , STR_500E_SUSPENSION_STEEL   , NULL, 0 },
-	{ 1930, 3,  7, 224, 160, 0xA23                             , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
-	{ 1930, 3,  8, 232, 208, 0xA23 | PALETTE_TO_STRUCT_BROWN   , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
-	{ 1930, 3,  9, 248, 240, 0xA23 | PALETTE_TO_STRUCT_RED     , STR_5010_CANTILEVER_STEEL   , NULL, 0 },
-	{ 1930, 0,  2, 240, 256, 0xA27                             , STR_500F_GIRDER_STEEL       , NULL, 0 },
-	{ 1995, 2, 16, 255, 320, 0xA28                             , STR_5014_TUBULAR_STEEL      , NULL, 0 },
-	{ 2005, 2, 32, 380, 512, 0xA28 | PALETTE_TO_STRUCT_YELLOW  , STR_5014_TUBULAR_STEEL      , NULL, 0 },
-	{ 2010, 2, 32, 510, 608, 0xA28 | PALETTE_TO_STRUCT_GREY    , STR_BRIDGE_TUBULAR_SILICON  , NULL, 0 }
-};
-
-Bridge _bridge[MAX_BRIDGES];
-
-
-// calculate the price factor for building a long bridge.
-// basically the cost delta is 1,1, 1, 2,2, 3,3,3, 4,4,4,4, 5,5,5,5,5, 6,6,6,6,6,6,  7,7,7,7,7,7,7,  8,8,8,8,8,8,8,8,
-int CalcBridgeLenCostFactor(int x)
-{
-	int n;
-	int r;
-
-	if (x < 2) return x;
-	x -= 2;
-	for (n = 0, r = 2;; n++) {
-		if (x <= n) return r + x * n;
-		r += n * n;
-		x -= n;
-	}
-}
-
-#define M(x) (1 << (x))
-enum {
-	// foundation, whole tile is leveled up --> 3 corners raised
-	BRIDGE_FULL_LEVELED_FOUNDATION = M(SLOPE_WSE) | M(SLOPE_NWS) | M(SLOPE_ENW) | M(SLOPE_SEN),
-	// foundation, tile is partly leveled up --> 1 corner raised
-	BRIDGE_PARTLY_LEVELED_FOUNDATION = M(SLOPE_W) | M(SLOPE_S) | M(SLOPE_E) | M(SLOPE_N),
-	// no foundations (X,Y direction)
-	BRIDGE_NO_FOUNDATION = M(SLOPE_FLAT) | M(SLOPE_SW) | M(SLOPE_SE) | M(SLOPE_NW) | M(SLOPE_NE),
-	BRIDGE_HORZ_RAMP = (BRIDGE_PARTLY_LEVELED_FOUNDATION | BRIDGE_NO_FOUNDATION) & ~M(SLOPE_FLAT)
-};
-#undef M
-
-static inline const PalSpriteID *GetBridgeSpriteTable(int index, byte table)
-{
-	const Bridge *bridge = &_bridge[index];
-	assert(table < 7);
-	if (bridge->sprite_table == NULL || bridge->sprite_table[table] == NULL) {
-		return _bridge_sprite_table[index][table];
-	} else {
-		return bridge->sprite_table[table];
-	}
-}
-
-static inline byte GetBridgeFlags(int index) { return _bridge[index].flags;}
-
-
-/** Check the slope at the bridge ramps in three easy steps:
- * - valid slopes without foundation
- * - valid slopes with foundation
- * - rest is invalid
- */
-#define M(x) (1 << (x))
-static int32 CheckBridgeSlopeNorth(Axis axis, Slope tileh)
-{
-	uint32 valid;
-
-	valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_NE) : M(SLOPE_NW));
-	if (HASBIT(valid, tileh)) return 0;
-
-	valid =
-		BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_N) | M(SLOPE_STEEP_N) |
-		(axis == AXIS_X ? M(SLOPE_E) | M(SLOPE_STEEP_E) : M(SLOPE_W) | M(SLOPE_STEEP_W));
-	if (HASBIT(valid, tileh)) return _price.terraform;
-
-	return CMD_ERROR;
-}
-
-static int32 CheckBridgeSlopeSouth(Axis axis, Slope tileh)
-{
-	uint32 valid;
-
-	valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_SW) : M(SLOPE_SE));
-	if (HASBIT(valid, tileh)) return 0;
-
-	valid =
-		BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_S) | M(SLOPE_STEEP_S) |
-		(axis == AXIS_X ? M(SLOPE_W) | M(SLOPE_STEEP_W) : M(SLOPE_E) | M(SLOPE_STEEP_E));
-	if (HASBIT(valid, tileh)) return _price.terraform;
-
-	return CMD_ERROR;
-}
-#undef M
-
-
-uint32 GetBridgeLength(TileIndex begin, TileIndex end)
-{
-	int x1 = TileX(begin);
-	int y1 = TileY(begin);
-	int x2 = TileX(end);
-	int y2 = TileY(end);
-
-	return abs(x2 + y2 - x1 - y1) - 1;
-}
-
-bool CheckBridge_Stuff(byte bridge_type, uint bridge_len)
-{
-	const Bridge *b = &_bridge[bridge_type];
-	uint max; // max possible length of a bridge (with patch 100)
-
-	if (bridge_type >= MAX_BRIDGES) return false;
-	if (b->avail_year > _cur_year) return false;
-
-	max = b->max_length;
-	if (max >= 16 && _patches.longbridges) max = 100;
-
-	return b->min_length <= bridge_len && bridge_len <= max;
-}
-
-/** Build a Bridge
- * @param end_tile end tile
- * @param p1 packed start tile coords (~ dx)
- * @param p2 various bitstuffed elements
- * - p2 = (bit 0- 7) - bridge type (hi bh)
- * - p2 = (bit 8-..) - rail type. bit15 ((x>>8)&0x80) means road bridge.
- */
-int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
-{
-	int bridge_type;
-	TransportType transport;
-	RailType railtype;
-	uint x;
-	uint y;
-	uint sx;
-	uint sy;
-	TileIndex tile_start;
-	TileIndex tile_end;
-	Slope tileh_start;
-	Slope tileh_end;
-	uint z_start;
-	uint z_end;
-	TileIndex tile;
-	TileIndexDiff delta;
-	uint bridge_len;
-	Axis direction;
-	int32 cost, terraformcost, ret;
-	bool allow_on_slopes;
-
-	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
-
-	/* unpack parameters */
-	bridge_type = GB(p2, 0, 8);
-
-	if (p1 >= MapSize()) return CMD_ERROR;
-
-	// type of bridge
-	if (HASBIT(p2, 15)) {
-		railtype = 0;
-		transport = TRANSPORT_ROAD;
-	} else {
-		if (!ValParamRailtype(GB(p2, 8, 8))) return CMD_ERROR;
-		railtype = GB(p2, 8, 8);
-		transport = TRANSPORT_RAIL;
-	}
-
-	x = TileX(end_tile);
-	y = TileY(end_tile);
-	sx = TileX(p1);
-	sy = TileY(p1);
-
-	/* check if valid, and make sure that (x,y) are smaller than (sx,sy) */
-	if (x == sx) {
-		if (y == sy) return_cmd_error(STR_5008_CANNOT_START_AND_END_ON);
-		direction = AXIS_Y;
-		if (y > sy) uintswap(y,sy);
-	} else if (y == sy) {
-		direction = AXIS_X;
-		if (x > sx) uintswap(x,sx);
-	} else {
-		return_cmd_error(STR_500A_START_AND_END_MUST_BE_IN);
-	}
-
-	/* set and test bridge length, availability */
-	bridge_len = sx + sy - x - y - 1;
-	if (!CheckBridge_Stuff(bridge_type, bridge_len)) return_cmd_error(STR_5015_CAN_T_BUILD_BRIDGE_HERE);
-
-	/* retrieve landscape height and ensure it's on land */
-	tile_start = TileXY(x, y);
-	tile_end = TileXY(sx, sy);
-	if (IsClearWaterTile(tile_start) || IsClearWaterTile(tile_end)) {
-		return_cmd_error(STR_02A0_ENDS_OF_BRIDGE_MUST_BOTH);
-	}
-
-	tileh_start = GetTileSlope(tile_start, &z_start);
-	tileh_end = GetTileSlope(tile_end, &z_end);
-
-	if (IsSteepSlope(tileh_start)) z_start += TILE_HEIGHT;
-	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_start)) {
-		z_start += TILE_HEIGHT;
-		tileh_start = SLOPE_FLAT;
-	}
-
-	if (IsSteepSlope(tileh_end)) z_end += TILE_HEIGHT;
-	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_end)) {
-		z_end += TILE_HEIGHT;
-		tileh_end = SLOPE_FLAT;
-	}
-
-	if (z_start != z_end) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
-
-	// Towns are not allowed to use bridges on slopes.
-	allow_on_slopes = (!_is_old_ai_player
-	                   && _current_player != OWNER_TOWN && _patches.build_on_slopes);
-
-	/* Try and clear the start landscape */
-
-	ret = DoCommand(tile_start, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
-	if (CmdFailed(ret)) return ret;
-	cost = ret;
-
-	terraformcost = CheckBridgeSlopeNorth(direction, tileh_start);
-	if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
-		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
-	cost += terraformcost;
-
-	/* Try and clear the end landscape */
-
-	ret = DoCommand(tile_end, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
-	if (CmdFailed(ret)) return ret;
-	cost += ret;
-
-	// false - end tile slope check
-	terraformcost = CheckBridgeSlopeSouth(direction, tileh_end);
-	if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
-		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
-	cost += terraformcost;
-
-	{
-		TileIndex Heads[] = {tile_start, tile_end};
-		int i;
-
-		for (i = 0; i < 2; i++) {
-			if (MayHaveBridgeAbove(Heads[i])) {
-				if (IsBridgeAbove(Heads[i])) {
-					TileIndex north_head = GetNorthernBridgeEnd(Heads[i]);
-
-					if (direction == GetBridgeAxis(Heads[i])) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-
-					if (z_start + TILE_HEIGHT == GetBridgeHeight(north_head)) {
-						return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-					}
-				}
-			}
-		}
-	}
-
-	/* do the drill? */
-	if (flags & DC_EXEC) {
-		DiagDirection dir = AxisToDiagDir(direction);
-
-		if (transport == TRANSPORT_RAIL) {
-			MakeRailBridgeRamp(tile_start, _current_player, bridge_type, dir, railtype);
-			MakeRailBridgeRamp(tile_end,   _current_player, bridge_type, ReverseDiagDir(dir), railtype);
-		} else {
-			MakeRoadBridgeRamp(tile_start, _current_player, bridge_type, dir);
-			MakeRoadBridgeRamp(tile_end,   _current_player, bridge_type, ReverseDiagDir(dir));
-		}
-		MarkTileDirtyByTile(tile_start);
-		MarkTileDirtyByTile(tile_end);
-	}
-
-	delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
-	for (tile = tile_start + delta; tile != tile_end; tile += delta) {
-		uint z;
-
-		if (GetTileSlope(tile, &z) != SLOPE_FLAT && z >= z_start) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
-
-		if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
-			/* Disallow crossing bridges for the time being */
-			return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-		}
-
-		switch (GetTileType(tile)) {
-			case MP_WATER:
-				if (!EnsureNoVehicle(tile)) return_cmd_error(STR_980E_SHIP_IN_THE_WAY);
-				if (!IsWater(tile) && !IsCoast(tile)) goto not_valid_below;
-				break;
-
-			case MP_RAILWAY:
-				if (!IsPlainRailTile(tile)) goto not_valid_below;
-				break;
-
-			case MP_STREET:
-				if (GetRoadTileType(tile) == ROAD_TILE_DEPOT) goto not_valid_below;
-				break;
-
-			case MP_TUNNEL:
-				break;
-
-			case MP_STREET_BRIDGE:
-			case MP_RAILWAY_BRIDGE:
-				if (direction == DiagDirToAxis(GetBridgeRampDirection(tile))) goto not_valid_below;
-				if (z_start < GetBridgeHeight(tile)) goto not_valid_below;
-				break;
-
-			case MP_UNMOVABLE:
-				if (!IsOwnedLand(tile)) goto not_valid_below;
-				break;
-
-			case MP_CLEAR:
-				if (IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-				break;
-
-			default:
-not_valid_below:;
-				/* try and clear the middle landscape */
-				ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
-				if (CmdFailed(ret)) return ret;
-				cost += ret;
-				break;
-		}
-
-		if (flags & DC_EXEC) {
-			SetBridgeMiddle(tile, direction);
-			MarkTileDirtyByTile(tile);
-		}
-	}
-
-	SetSignalsOnBothDir(tile_start, AxisToTrack(direction));
-	YapfNotifyTrackLayoutChange(tile_start, AxisToTrack(direction));
-
-	/* for human player that builds the bridge he gets a selection to choose from bridges (DC_QUERY_COST)
-	 * It's unnecessary to execute this command every time for every bridge. So it is done only
-	 * and cost is computed in "bridge_gui.c". For AI, Towns this has to be of course calculated
-	 */
-	if (!(flags & DC_QUERY_COST)) {
-		const Bridge *b = &_bridge[bridge_type];
-
-		bridge_len += 2; // begin and end tiles/ramps
-
-		if (IsValidPlayer(_current_player) && !_is_old_ai_player)
-			bridge_len = CalcBridgeLenCostFactor(bridge_len);
-
-		cost += (int64)bridge_len * _price.build_bridge * b->price >> 8;
-	}
-
-	return cost;
-}
-
-
-/** Build Tunnel.
- * @param tile start tile of tunnel
- * @param p1 railtype, 0x200 for road tunnel
- * @param p2 unused
- */
-int32 CmdBuildTunnel(TileIndex start_tile, uint32 flags, uint32 p1, uint32 p2)
-{
-	TileIndexDiff delta;
-	TileIndex end_tile;
-	DiagDirection direction;
-	Slope start_tileh;
-	Slope end_tileh;
-	uint start_z;
-	uint end_z;
-	int32 cost;
-	int32 ret;
-
-	_build_tunnel_endtile = 0;
-
-	if (p1 != 0x200 && !ValParamRailtype(p1)) return CMD_ERROR;
-
-	start_tileh = GetTileSlope(start_tile, &start_z);
-
-	switch (start_tileh) {
-		case SLOPE_SW: direction = DIAGDIR_SW; break;
-		case SLOPE_SE: direction = DIAGDIR_SE; break;
-		case SLOPE_NW: direction = DIAGDIR_NW; break;
-		case SLOPE_NE: direction = DIAGDIR_NE; break;
-		default: return_cmd_error(STR_500B_SITE_UNSUITABLE_FOR_TUNNEL);
-	}
-
-	ret = DoCommand(start_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
-	if (CmdFailed(ret)) return ret;
-
-	/* XXX - do NOT change 'ret' in the loop, as it is used as the price
-	 * for the clearing of the entrance of the tunnel. Assigning it to
-	 * cost before the loop will yield different costs depending on start-
-	 * position, because of increased-cost-by-length: 'cost += cost >> 3' */
-	cost = 0;
-	delta = TileOffsByDiagDir(direction);
-	end_tile = start_tile;
-	for (;;) {
-		end_tile += delta;
-		end_tileh = GetTileSlope(end_tile, &end_z);
-
-		if (start_z == end_z) break;
-
-		if (!_cheats.crossing_tunnels.value && IsTunnelInWay(end_tile, start_z)) {
-			return_cmd_error(STR_5003_ANOTHER_TUNNEL_IN_THE_WAY);
-		}
-
-		cost += _price.build_tunnel;
-		cost += cost >> 3; // add a multiplier for longer tunnels
-		if (cost >= 400000000) cost = 400000000;
-	}
-
-	/* Add the cost of the entrance */
-	cost += _price.build_tunnel + ret;
-
-	// if the command fails from here on we want the end tile to be highlighted
-	_build_tunnel_endtile = end_tile;
-
-	// slope of end tile must be complementary to the slope of the start tile
-	if (end_tileh != ComplementSlope(start_tileh)) {
-		ret = DoCommand(end_tile, end_tileh & start_tileh, 0, flags, CMD_TERRAFORM_LAND);
-		if (CmdFailed(ret)) return_cmd_error(STR_5005_UNABLE_TO_EXCAVATE_LAND);
-	} else {
-		ret = DoCommand(end_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
-		if (CmdFailed(ret)) return ret;
-	}
-	cost += _price.build_tunnel + ret;
-
-	if (flags & DC_EXEC) {
-		if (GB(p1, 9, 1) == TRANSPORT_RAIL) {
-			MakeRailTunnel(start_tile, _current_player, direction,                 GB(p1, 0, 4));
-			MakeRailTunnel(end_tile,   _current_player, ReverseDiagDir(direction), GB(p1, 0, 4));
-			UpdateSignalsOnSegment(start_tile, direction);
-			YapfNotifyTrackLayoutChange(start_tile, AxisToTrack(DiagDirToAxis(direction)));
-		} else {
-			MakeRoadTunnel(start_tile, _current_player, direction);
-			MakeRoadTunnel(end_tile,   _current_player, ReverseDiagDir(direction));
-		}
-	}
-
-	return cost;
-}
-
-TileIndex CheckTunnelBusy(TileIndex tile, uint *length)
-{
-	uint z = GetTileZ(tile);
-	DiagDirection dir = GetTunnelDirection(tile);
-	TileIndexDiff delta = TileOffsByDiagDir(dir);
-	uint len = 0;
-	TileIndex starttile = tile;
-	Vehicle *v;
-
-	do {
-		tile += delta;
-		len++;
-	} while (
-		!IsTunnelTile(tile) ||
-		ReverseDiagDir(GetTunnelDirection(tile)) != dir ||
-		GetTileZ(tile) != z
-	);
-
-	v = FindVehicleBetween(starttile, tile, z);
-	if (v != NULL) {
-		_error_message = v->type == VEH_Train ?
-			STR_5000_TRAIN_IN_TUNNEL : STR_5001_ROAD_VEHICLE_IN_TUNNEL;
-		return INVALID_TILE;
-	}
-
-	if (length != NULL) *length = len;
-	return tile;
-}
-
-static inline bool CheckAllowRemoveTunnelBridge(TileIndex tile)
-{
-	/* Floods can remove anything as well as the scenario editor */
-	if (_current_player == OWNER_WATER || _game_mode == GM_EDITOR) return true;
-	/* Obviously if the bridge/tunnel belongs to us, or no-one, we can remove it */
-	if (CheckTileOwnership(tile) || IsTileOwner(tile, OWNER_NONE)) return true;
-	/* Otherwise we can only remove town-owned stuff with extra patch-settings, or cheat */
-	if (IsTileOwner(tile, OWNER_TOWN) && (_patches.extra_dynamite || _cheats.magic_bulldozer.value)) return true;
-	return false;
-}
-
-static int32 DoClearTunnel(TileIndex tile, uint32 flags)
-{
-	Town *t = NULL;
-	TileIndex endtile;
-	uint length;
-
-	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
-
-	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
-
-	endtile = CheckTunnelBusy(tile, &length);
-	if (endtile == INVALID_TILE) return CMD_ERROR;
-
-	_build_tunnel_endtile = endtile;
-
-	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
-		t = ClosestTownFromTile(tile, (uint)-1); // town penalty rating
-
-		/* Check if you are allowed to remove the tunnel owned by a town
-		 * Removal depends on difficulty settings */
-		if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
-			SetDParam(0, t->index);
-			return_cmd_error(STR_2009_LOCAL_AUTHORITY_REFUSES);
-		}
-	}
-
-	if (flags & DC_EXEC) {
-		// We first need to request the direction before calling DoClearSquare
-		//  else the direction is always 0.. dah!! ;)
-		DiagDirection dir = GetTunnelDirection(tile);
-		Track track;
-
-		// Adjust the town's player rating. Do this before removing the tile owner info.
-		if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR)
-			ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM);
-
-		DoClearSquare(tile);
-		DoClearSquare(endtile);
-		UpdateSignalsOnSegment(tile, ReverseDiagDir(dir));
-		UpdateSignalsOnSegment(endtile, dir);
-		track = AxisToTrack(DiagDirToAxis(dir));
-		YapfNotifyTrackLayoutChange(tile, track);
-		YapfNotifyTrackLayoutChange(endtile, track);
-	}
-	return _price.clear_tunnel * (length + 1);
-}
-
-
-static bool IsVehicleOnBridge(TileIndex starttile, TileIndex endtile, uint z)
-{
-	const Vehicle *v;
-	FOR_ALL_VEHICLES(v) {
-		if ((v->tile == starttile || v->tile == endtile) && v->z_pos == z) {
-			_error_message = VehicleInTheWayErrMsg(v);
-			return true;
-		}
-	}
-	return false;
-}
-
-static int32 DoClearBridge(TileIndex tile, uint32 flags)
-{
-	DiagDirection direction;
-	TileIndexDiff delta;
-	TileIndex endtile;
-	Town *t = NULL;
-
-	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
-
-	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
-
-	endtile = GetOtherBridgeEnd(tile);
-
-	if (!EnsureNoVehicle(tile) ||
-			!EnsureNoVehicle(endtile) ||
-			IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
-		return CMD_ERROR;
-	}
-
-	direction = GetBridgeRampDirection(tile);
-	delta = TileOffsByDiagDir(direction);
-
-	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
-		t = ClosestTownFromTile(tile, (uint)-1); // town penalty rating
-
-		/* Check if you are allowed to remove the bridge owned by a town
-		 * Removal depends on difficulty settings */
-		if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
-			SetDParam(0, t->index);
-			return_cmd_error(STR_2009_LOCAL_AUTHORITY_REFUSES);
-		}
-	}
-
-	if (flags & DC_EXEC) {
-		TileIndex c;
-		Track track;
-
-		//checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
-		// you have a "Poor" (0) town rating
-		if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR)
-			ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM);
-
-		DoClearSquare(tile);
-		DoClearSquare(endtile);
-		for (c = tile + delta; c != endtile; c += delta) {
-				ClearBridgeMiddle(c);
-			MarkTileDirtyByTile(c);
-		}
-
-		UpdateSignalsOnSegment(tile, ReverseDiagDir(direction));
-		UpdateSignalsOnSegment(endtile, direction);
-		track = AxisToTrack(DiagDirToAxis(direction));
-		YapfNotifyTrackLayoutChange(tile, track);
-		YapfNotifyTrackLayoutChange(endtile, track);
-	}
-
-	return (DistanceManhattan(tile, endtile) + 1) * _price.clear_bridge;
-}
-
-static int32 ClearTile_Tunnel(TileIndex tile, byte flags)
-{
-	assert(IsTunnelTile(tile));
-	if (flags & DC_AUTO) return_cmd_error(STR_5006_MUST_DEMOLISH_TUNNEL_FIRST);
-	return DoClearTunnel(tile, flags);
-}
-
-static int32 ClearTile_Bridge(TileIndex tile, byte flags)
-{
-	assert(IsBridgeTile(tile));
-	if (flags & DC_AUTO) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-	return DoClearBridge(tile, flags);
-}
-
-int32 DoConvertTunnelBridgeRail(TileIndex tile, RailType totype, bool exec)
-{
-	TileIndex endtile;
-
-	if (IsTunnelTile(tile) && GetTunnelTransportType(tile) == TRANSPORT_RAIL) {
-		uint length;
-
-		if (!CheckTileOwnership(tile)) return CMD_ERROR;
-
-		if (GetRailType(tile) == totype) return CMD_ERROR;
-
-		// 'hidden' elrails can't be downgraded to normal rail when elrails are disabled
-		if (_patches.disable_elrails && totype == RAILTYPE_RAIL && GetRailType(tile) == RAILTYPE_ELECTRIC) return CMD_ERROR;
-
-		endtile = CheckTunnelBusy(tile, &length);
-		if (endtile == INVALID_TILE) return CMD_ERROR;
-
-		if (exec) {
-			Track track;
-			SetRailType(tile, totype);
-			SetRailType(endtile, totype);
-			MarkTileDirtyByTile(tile);
-			MarkTileDirtyByTile(endtile);
-
-			track = AxisToTrack(DiagDirToAxis(GetTunnelDirection(tile)));
-			YapfNotifyTrackLayoutChange(tile, track);
-			YapfNotifyTrackLayoutChange(endtile, track);
-		}
-		return (length + 1) * (_price.build_rail >> 1);
-	} else if (IsBridgeTile(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
-
-		if (!CheckTileOwnership(tile)) return CMD_ERROR;
-
-		endtile = GetOtherBridgeEnd(tile);
-
-		if (!EnsureNoVehicle(tile) ||
-				!EnsureNoVehicle(endtile) ||
-				IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
-			return CMD_ERROR;
-		}
-
-		if (GetRailType(tile) == totype) return CMD_ERROR;
-
-		if (exec) {
-			TileIndexDiff delta;
-			Track track;
-
-			SetRailType(tile, totype);
-			SetRailType(endtile, totype);
-			MarkTileDirtyByTile(tile);
-			MarkTileDirtyByTile(endtile);
-
-			track = AxisToTrack(DiagDirToAxis(GetBridgeRampDirection(tile)));
-			YapfNotifyTrackLayoutChange(tile, track);
-			YapfNotifyTrackLayoutChange(endtile, track);
-
-			delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));
-			for (tile += delta; tile != endtile; tile += delta) {
-				MarkTileDirtyByTile(tile); // TODO encapsulate this into a function
-			}
-		}
-
-		return (DistanceManhattan(tile, endtile) + 1) * (_price.build_rail >> 1);
-	} else {
-		return CMD_ERROR;
-	}
-}
-
-
-static void DrawBridgePillars(PalSpriteID image, const TileInfo* ti, Axis axis, uint type, int x, int y, int z)
-{
-	if (image != 0) {
-		bool drawfarpillar = !HASBIT(GetBridgeFlags(type), 0);
-		int back_height, front_height;
-		int i = z;
-		const byte *p;
-
-		static const byte _tileh_bits[4][8] = {
-			{ 2, 1, 8, 4,  16,  2, 0, 9 },
-			{ 1, 8, 4, 2,   2, 16, 9, 0 },
-			{ 4, 8, 1, 2,  16,  2, 0, 9 },
-			{ 2, 4, 8, 1,   2, 16, 9, 0 }
-		};
-
-		if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-
-		p = _tileh_bits[(image & 1) * 2 + (axis == AXIS_X ? 0 : 1)];
-		front_height = ti->z + (ti->tileh & p[0] ? TILE_HEIGHT : 0);
-		back_height  = ti->z + (ti->tileh & p[1] ? TILE_HEIGHT : 0);
-
-		if (IsSteepSlope(ti->tileh)) {
-			if (!(ti->tileh & p[2])) front_height += TILE_HEIGHT;
-			if (!(ti->tileh & p[3])) back_height  += TILE_HEIGHT;
-		}
-
-		for (; z >= front_height || z >= back_height; z -= TILE_HEIGHT) {
-			/* HACK set height of the BB of pillars to 1, because the origin of the
-			 * sprites is at the top
-			 */
-			if (z >= front_height) { // front facing pillar
-				AddSortableSpriteToDraw(image, x, y, p[4], p[5], 1, z);
-			}
-
-			if (drawfarpillar && z >= back_height && z < i - TILE_HEIGHT) { // back facing pillar
-				AddSortableSpriteToDraw(image, x - p[6], y - p[7], p[4], p[5], 1, z);
-			}
-		}
-	}
-}
-
-uint GetBridgeFoundation(Slope tileh, Axis axis)
-{
-	uint i;
-
-	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) return tileh;
-
-	// inclined sloped building
-	switch (tileh) {
-		case SLOPE_W:
-		case SLOPE_STEEP_W: i = 0; break;
-		case SLOPE_S:
-		case SLOPE_STEEP_S: i = 2; break;
-		case SLOPE_E:
-		case SLOPE_STEEP_E: i = 4; break;
-		case SLOPE_N:
-		case SLOPE_STEEP_N: i = 6; break;
-		default: return 0;
-	}
-	if (axis != AXIS_X) ++i;
-	return i + 15;
-}
-
-/**
- * Draws a tunnel tile.
- * Please note that in this code, "roads" are treated as railtype 1, whilst the real railtypes are 0, 2 and 3
- */
-static void DrawTile_Tunnel(TileInfo *ti)
-{
-	uint32 image;
-
-	if (GetTunnelTransportType(ti->tile) == TRANSPORT_RAIL) {
-		image = GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.tunnel;
-	} else {
-		image = SPR_TUNNEL_ENTRY_REAR_ROAD;
-	}
-
-	if (HasTunnelSnowOrDesert(ti->tile)) image += 32;
-
-	image += GetTunnelDirection(ti->tile) * 2;
-	DrawGroundSprite(image);
-	if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
-
-	AddSortableSpriteToDraw(image+1, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, 1, 1, 8, (byte)ti->z);
-	DrawBridgeMiddle(ti);
-}
-
-/**
- * Draws a bridge tile.
- * base_offset is where the sprite selection comes into play
- * and it works a bit like a bitmask.<p> For bridge heads:
- * <ul><li>Bit 0: direction</li>
- * <li>Bit 1: northern or southern heads</li>
- * <li>Bit 2: Set if the bridge head is sloped</li>
- * <li>Bit 3 and more: Railtype Specific subset</li>
- * </ul>
- * Please note that in this code, "roads" are treated as railtype 1, whilst the real railtypes are 0, 2 and 3
- */
-static void DrawTile_Bridge(TileInfo *ti)
-{
-	uint32 image;
-
-	int base_offset;
-	bool ice = HasBridgeSnowOrDesert(ti->tile);
-
-	if (GetBridgeTransportType(ti->tile) == TRANSPORT_RAIL) {
-		base_offset = GetRailTypeInfo(GetRailType(ti->tile))->bridge_offset;
-		assert(base_offset != 8); /* This one is used for roads */
-	} else {
-		base_offset = 8;
-	}
-
-	/* as the lower 3 bits are used for other stuff, make sure they are clear */
-	assert( (base_offset & 0x07) == 0x00);
-
-	if (!HASBIT(BRIDGE_NO_FOUNDATION, ti->tileh)) {
-		int f = GetBridgeFoundation(ti->tileh, DiagDirToAxis(GetBridgeRampDirection(ti->tile)));
-		if (f != 0) DrawFoundation(ti, f);
-	}
-
-	// HACK Wizardry to convert the bridge ramp direction into a sprite offset
-	base_offset += (6 - GetBridgeRampDirection(ti->tile)) % 4;
-
-	if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
-
-	/* Table number 6 always refers to the bridge heads for any bridge type */
-	image = GetBridgeSpriteTable(GetBridgeType(ti->tile), 6)[base_offset];
-
-	if (!ice) {
-		DrawClearLandTile(ti, 3);
-	} else {
-		DrawGroundSprite(SPR_FLAT_SNOWY_TILE + _tileh_to_sprite[ti->tileh]);
-	}
-
-	if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
-
-	// draw ramp
-	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-	/* HACK set the height of the BB of a sloped ramp to 1 so a vehicle on
-	 * it doesn't disappear behind it
-	 */
-	AddSortableSpriteToDraw(
-		image, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 1 : 8, ti->z
-	);
-
-	DrawBridgeMiddle(ti);
-}
-
-
-/** Compute bridge piece. Computes the bridge piece to display depending on the position inside the bridge.
- * bridges pieces sequence (middle parts)
- * bridge len 1: 0
- * bridge len 2: 0 1
- * bridge len 3: 0 4 1
- * bridge len 4: 0 2 3 1
- * bridge len 5: 0 2 5 3 1
- * bridge len 6: 0 2 3 2 3 1
- * bridge len 7: 0 2 3 4 2 3 1
- * #0 - always as first, #1 - always as last (if len>1)
- * #2,#3 are to pair in order
- * for odd bridges: #5 is going in the bridge middle if on even position, #4 on odd (counting from 0)
- * @param north Northernmost tile of bridge
- * @param south Southernmost tile of bridge
- * @return Index of bridge piece
- */
-static uint CalcBridgePiece(uint north, uint south)
-{
-	if (north == 1) {
-		return 0;
-	} else if (south == 1) {
-		return 1;
-	} else if (north < south) {
-		return north & 1 ? 3 : 2;
-	} else if (north > south) {
-		return south & 1 ? 2 : 3;
-	} else {
-		return north & 1 ? 5 : 4;
-	}
-}
-
-
-void DrawBridgeMiddle(const TileInfo* ti)
-{
-	const PalSpriteID* b;
-	PalSpriteID image;
-	uint base_offset;
-	TileIndex rampnorth;
-	TileIndex rampsouth;
-	Axis axis;
-	uint piece;
-	uint type;
-	int x;
-	int y;
-	uint z;
-
-	if (!IsBridgeAbove(ti->tile)) return;
-
-	rampnorth = GetNorthernBridgeEnd(ti->tile);
-	rampsouth = GetSouthernBridgeEnd(ti->tile);
-
-	axis = GetBridgeAxis(ti->tile);
-	piece = CalcBridgePiece(
-		DistanceManhattan(ti->tile, rampnorth),
-		DistanceManhattan(ti->tile, rampsouth)
-	);
-	type = GetBridgeType(rampsouth);
-
-	if (GetBridgeTransportType(rampsouth) == TRANSPORT_RAIL) {
-		base_offset = GetRailTypeInfo(GetRailType(rampsouth))->bridge_offset;
-	} else {
-		base_offset = 8;
-	}
-
-	b = base_offset + GetBridgeSpriteTable(type, piece);
-	if (axis != AXIS_X) b += 4;
-
-	x = ti->x;
-	y = ti->y;
-	z = GetBridgeHeight(rampsouth) - 3;
-
-	image = b[0];
-	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-	if (axis == AXIS_X) {
-		AddSortableSpriteToDraw(image, x, y, 16, 11, 1, z);
-	} else {
-		AddSortableSpriteToDraw(image, x, y, 11, 16, 1, z);
-	}
-
-	image = b[1];
-	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-
-	// draw roof, the component of the bridge which is logically between the vehicle and the camera
-	if (axis == AXIS_X) {
-		y += 12;
-		if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 16, 1, 0x28, z);
-	} else {
-		x += 12;
-		if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 1, 16, 0x28, z);
-	}
-
-	if (GetRailType(rampsouth) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
-
-	if (ti->z + 5 == z) {
-		// draw poles below for small bridges
-		image = b[2];
-		if (image != 0) {
-			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-			DrawGroundSpriteAt(image, x, y, z);
-		}
-	} else if (_patches.bridge_pillars) {
-		// draw pillars below for high bridges
-		DrawBridgePillars(b[2], ti, axis, type, x, y, z);
-	}
-}
-
-
-uint SetSpeedLimitOnBridge(Vehicle *v)
-{
-	uint bridge_speed;
-	if (v->vehstatus & VS_HIDDEN) return v->max_speed; /* in tunnel */
-
-	bridge_speed = _bridge[GetBridgeType(v->tile)].speed;
-
-	if (v->type == VEH_Road) bridge_speed *= 2; /* XXX give vehicles proper speeds */
-
-	if (v->cur_speed > bridge_speed) v->cur_speed = bridge_speed;
-	return bridge_speed;
-}
-
-
-/** Gets the absolute z coordinate of a point inside a tunnel tile
- *  When we're on the track (that means between position 5 and 10)
- *  on the coordinate perpendicular to the track it returns only the
- *  base height of the tile (because the track is horizontal).
- *  Outside this range (from 0 to 4 and from 11 to 15) it returns the
- *  "true" Z coordinate of the tile by taking the slope into account
- *  @param tile The index of the tile we are talking about
- *  @param x Absolute or relative x coordinate
- *  @param y Absolute or relative y coordinate
- *  @return Absolute z coordinate
- */
-static uint GetSlopeZ_Tunnel(TileIndex tile, uint x, uint y)
-{
-	uint z, pos;
-	Slope tileh = GetTileSlope(tile, &z);
-
-	x &= 0xF;
-	y &= 0xF;
-
-	pos = (DiagDirToAxis(GetTunnelDirection(tile)) == AXIS_X ? y : x);
-
-	// In the tunnel entrance?
-	if (5 <= pos && pos <= 10) return z;
-
-	return z + GetPartialZ(x, y, tileh);
-}
-
-/** Gets the absolute z coordinate of a point inside a bridge tile
- *  When we're on the track (that means between position 5 and 10)
- *  on the coordinate perpendicular to the track it returns the base
- *  height of the ramp
- *  Outside this range (from 0 to 4 and from 11 to 15) it returns the
- *  "true" Z coordinate of the tile by taking the slope into account
- *  @param tile The index of the tile we are talking about
- *  @param x Absolute or relative x coordinate
- *  @param y Absolute or relative y coordinate
- *  @return Absolute z coordinate
- */
-static uint GetSlopeZ_Bridge(TileIndex tile, uint x, uint y)
-{
-	uint z, pos;
-	Slope tileh = GetTileSlope(tile, &z);
-	DiagDirection dir = GetBridgeRampDirection(tile);
-
-	x &= 0xF;
-	y &= 0xF;
-
-	pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
-
-	// On the bridge ramp?
-	if (5 <= pos && pos <= 10) {
-		uint delta;
-
-		if (IsSteepSlope(tileh)) return z + TILE_HEIGHT * 2;
-
-		if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + TILE_HEIGHT;
-
-		if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += TILE_HEIGHT;
-		switch (dir) {
-			default: NOT_REACHED();
-			case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
-			case DIAGDIR_SE: delta = y / 2; break;
-			case DIAGDIR_SW: delta = x / 2; break;
-			case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
-		}
-		return z + 1 + delta;
-	} else {
-		uint f = GetBridgeFoundation(tileh, DiagDirToAxis(dir));
-
-		if (f != 0) {
-			if (IsSteepSlope(tileh)) {
-				z += TILE_HEIGHT;
-			} else if (f < 15) {
-				return z + TILE_HEIGHT;
-			}
-			tileh = _inclined_tileh[f - 15];
-		}
-	}
-	return z + GetPartialZ(x, y, tileh);
-}
-
-static Slope GetSlopeTileh_Tunnel(TileIndex tile, Slope tileh)
-{
-	return tileh;
-}
-
-static Slope GetSlopeTileh_Bridge(TileIndex tile, Slope tileh)
-{
-	if (HASBIT(BRIDGE_NO_FOUNDATION, tileh)) {
-		return tileh;
-	} else {
-		uint f = GetBridgeFoundation(tileh, DiagDirToAxis(GetBridgeRampDirection(tile)));
-
-		if (f == 0) return tileh;
-		if (f < 15) return SLOPE_FLAT;
-		return _inclined_tileh[f - 15];
-	}
-}
-
-static void GetAcceptedCargo_Tunnel(TileIndex tile, AcceptedCargo ac)
-{
-	/* not used */
-}
-
-static void GetAcceptedCargo_Bridge(TileIndex tile, AcceptedCargo ac)
-{
-	/* not used */
-}
-
-static const StringID _bridge_tile_str[(MAX_BRIDGES + 3) + (MAX_BRIDGES + 3)] = {
-	STR_501F_WOODEN_RAIL_BRIDGE,
-	STR_5020_CONCRETE_RAIL_BRIDGE,
-	STR_501C_STEEL_GIRDER_RAIL_BRIDGE,
-	STR_501E_REINFORCED_CONCRETE_SUSPENSION,
-	STR_501B_STEEL_SUSPENSION_RAIL_BRIDGE,
-	STR_501B_STEEL_SUSPENSION_RAIL_BRIDGE,
-	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
-	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
-	STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
-	STR_501C_STEEL_GIRDER_RAIL_BRIDGE,
-	STR_5027_TUBULAR_RAIL_BRIDGE,
-	STR_5027_TUBULAR_RAIL_BRIDGE,
-	STR_5027_TUBULAR_RAIL_BRIDGE,
-	0, 0, 0,
-
-	STR_5025_WOODEN_ROAD_BRIDGE,
-	STR_5026_CONCRETE_ROAD_BRIDGE,
-	STR_5022_STEEL_GIRDER_ROAD_BRIDGE,
-	STR_5024_REINFORCED_CONCRETE_SUSPENSION,
-	STR_5021_STEEL_SUSPENSION_ROAD_BRIDGE,
-	STR_5021_STEEL_SUSPENSION_ROAD_BRIDGE,
-	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
-	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
-	STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
-	STR_5022_STEEL_GIRDER_ROAD_BRIDGE,
-	STR_5028_TUBULAR_ROAD_BRIDGE,
-	STR_5028_TUBULAR_ROAD_BRIDGE,
-	STR_5028_TUBULAR_ROAD_BRIDGE,
-	0, 0, 0,
-};
-
-static void GetTileDesc_Tunnel(TileIndex tile, TileDesc *td)
-{
-	td->str = (GetTunnelTransportType(tile) == TRANSPORT_RAIL) ?  STR_5017_RAILROAD_TUNNEL : STR_5018_ROAD_TUNNEL;
-	td->owner = GetTileOwner(tile);
-}
-
-static void GetTileDesc_Bridge(TileIndex tile, TileDesc *td)
-{
-	td->str = _bridge_tile_str[GetBridgeTransportType(tile) << 4 | GetBridgeType(tile)];
-	td->owner = GetTileOwner(tile);
-}
-
-
-static void AnimateTile_Tunnel(TileIndex tile)
-{
-	/* not used */
-}
-
-static void AnimateTile_Bridge(TileIndex tile)
-{
-	/* not used */
-}
-
-static void TileLoop_Tunnel(TileIndex tile)
-{
-	bool snow_or_desert = HasTunnelSnowOrDesert(tile);
-	switch (_opt.landscape) {
-		case LT_HILLY:
-			if (snow_or_desert != (GetTileZ(tile) > _opt.snow_line)) {
-				SetTunnelSnowOrDesert(tile, !snow_or_desert);
-				MarkTileDirtyByTile(tile);
-			}
-			break;
-
-		case LT_DESERT:
-			if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
-				SetTunnelSnowOrDesert(tile, true);
-				MarkTileDirtyByTile(tile);
-			}
-			break;
-	}
-}
-
-static void TileLoop_Bridge(TileIndex tile)
-{
-	bool snow_or_desert = HasBridgeSnowOrDesert(tile);
-	switch (_opt.landscape) {
-		case LT_HILLY:
-			if (snow_or_desert != (GetTileZ(tile) > _opt.snow_line)) {
-				SetBridgeSnowOrDesert(tile, !snow_or_desert);
-				MarkTileDirtyByTile(tile);
-			}
-			break;
-
-		case LT_DESERT:
-			if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
-				SetBridgeSnowOrDesert(tile, true);
-				MarkTileDirtyByTile(tile);
-			}
-			break;
-	}
-}
-
-static void ClickTile_Tunnel(TileIndex tile)
-{
-	/* not used */
-}
-
-static void ClickTile_Bridge(TileIndex tile)
-{
-	/* not used */
-}
-
-
-static uint32 GetTileTrackStatus_Tunnel(TileIndex tile, TransportType mode)
-{
-	if (GetTunnelTransportType(tile) != mode) return 0;
-	return AxisToTrackBits(DiagDirToAxis(GetTunnelDirection(tile))) * 0x101;
-}
-
-static uint32 GetTileTrackStatus_Bridge(TileIndex tile, TransportType mode)
-{
-	if (GetBridgeTransportType(tile) != mode) return 0;
-	return AxisToTrackBits(DiagDirToAxis(GetBridgeRampDirection(tile))) * 0x101;
-}
-
-static void ChangeTileOwner_Tunnel(TileIndex tile, PlayerID old_player, PlayerID new_player)
-{
-	if (!IsTileOwner(tile, old_player)) return;
-
-	if (new_player != PLAYER_SPECTATOR) {
-		SetTileOwner(tile, new_player);
-	} else {
-		DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
-	}
-}
-
-static void ChangeTileOwner_Bridge(TileIndex tile, PlayerID old_player, PlayerID new_player)
-{
-	if (!IsTileOwner(tile, old_player)) return;
-
-	if (new_player != PLAYER_SPECTATOR) {
-		SetTileOwner(tile, new_player);
-	} else {
-		DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
-	}
-}
-
-
-static const byte _tunnel_fractcoord_1[4]    = {0x8E, 0x18, 0x81, 0xE8};
-static const byte _tunnel_fractcoord_2[4]    = {0x81, 0x98, 0x87, 0x38};
-static const byte _tunnel_fractcoord_3[4]    = {0x82, 0x88, 0x86, 0x48};
-static const byte _exit_tunnel_track[4]      = {1, 2, 1, 2};
-
-static const byte _road_exit_tunnel_state[4] = {8, 9, 0, 1};
-static const byte _road_exit_tunnel_frame[4] = {2, 7, 9, 4};
-
-static const byte _tunnel_fractcoord_4[4]    = {0x52, 0x85, 0x98, 0x29};
-static const byte _tunnel_fractcoord_5[4]    = {0x92, 0x89, 0x58, 0x25};
-static const byte _tunnel_fractcoord_6[4]    = {0x92, 0x89, 0x56, 0x45};
-static const byte _tunnel_fractcoord_7[4]    = {0x52, 0x85, 0x96, 0x49};
-
-static uint32 VehicleEnter_Tunnel(Vehicle *v, TileIndex tile, int x, int y)
-{
-	int z = GetSlopeZ(x, y) - v->z_pos;
-
-	byte fc;
-	DiagDirection dir;
-	DiagDirection vdir;
-
-	if (myabs(z) > 2) return 8;
-
-	if (v->type == VEH_Train) {
-		fc = (x & 0xF) + (y << 4);
-
-		dir = GetTunnelDirection(tile);
-		vdir = DirToDiagDir(v->direction);
-
-		if (v->u.rail.track != 0x40 && dir == vdir) {
-			if (IsFrontEngine(v) && fc == _tunnel_fractcoord_1[dir]) {
-				if (!PlayVehicleSound(v, VSE_TUNNEL) && v->spritenum < 4) {
-					SndPlayVehicleFx(SND_05_TRAIN_THROUGH_TUNNEL, v);
-				}
-				return 0;
-			}
-			if (fc == _tunnel_fractcoord_2[dir]) {
-				v->tile = tile;
-				v->u.rail.track = 0x40;
-				v->vehstatus |= VS_HIDDEN;
-				return 4;
-			}
-		}
-
-		if (dir == ReverseDiagDir(vdir) && fc == _tunnel_fractcoord_3[dir] && z == 0) {
-			/* We're at the tunnel exit ?? */
-			v->tile = tile;
-			v->u.rail.track = _exit_tunnel_track[dir];
-			assert(v->u.rail.track);
-			v->vehstatus &= ~VS_HIDDEN;
-			return 4;
-		}
-	} else if (v->type == VEH_Road) {
-		fc = (x & 0xF) + (y << 4);
-		dir = GetTunnelDirection(tile);
-		vdir = DirToDiagDir(v->direction);
-
-		// Enter tunnel?
-		if (v->u.road.state != 0xFF && dir == vdir) {
-			if (fc == _tunnel_fractcoord_4[dir] ||
-					fc == _tunnel_fractcoord_5[dir]) {
-				v->tile = tile;
-				v->u.road.state = 0xFF;
-				v->vehstatus |= VS_HIDDEN;
-				return 4;
-			} else {
-				return 0;
-			}
-		}
-
-		if (dir == ReverseDiagDir(vdir) && (
-					/* We're at the tunnel exit ?? */
-					fc == _tunnel_fractcoord_6[dir] ||
-					fc == _tunnel_fractcoord_7[dir]
-				) &&
-				z == 0) {
-			v->tile = tile;
-			v->u.road.state = _road_exit_tunnel_state[dir];
-			v->u.road.frame = _road_exit_tunnel_frame[dir];
-			v->vehstatus &= ~VS_HIDDEN;
-			return 4;
-		}
-	}
-	return 0;
-}
-
-static uint32 VehicleEnter_Bridge(Vehicle *v, TileIndex tile, int x, int y)
-{
-	int z = GetSlopeZ(x, y) - v->z_pos;
-
-	DiagDirection dir;
-
-	if (myabs(z) > 2) return 8;
-
-	if (v->type == VEH_Road || (v->type == VEH_Train && IsFrontEngine(v))) {
-		/* modify speed of vehicle */
-		uint16 spd = _bridge[GetBridgeType(tile)].speed;
-
-		if (v->type == VEH_Road) spd *= 2;
-		if (v->cur_speed > spd) v->cur_speed = spd;
-	}
-
-	dir = GetBridgeRampDirection(tile);
-	if (DirToDiagDir(v->direction) == dir) {
-		switch (dir) {
-			default: NOT_REACHED();
-			case DIAGDIR_NE: if ((x & 0xF) != 0)             return 0; break;
-			case DIAGDIR_SE: if ((y & 0xF) != TILE_SIZE - 1) return 0; break;
-			case DIAGDIR_SW: if ((x & 0xF) != TILE_SIZE - 1) return 0; break;
-			case DIAGDIR_NW: if ((y & 0xF) != 0)             return 0; break;
-		}
-		if (v->type == VEH_Train) {
-			v->u.rail.track = 0x40;
-			CLRBIT(v->u.rail.flags, VRF_GOINGUP);
-			CLRBIT(v->u.rail.flags, VRF_GOINGDOWN);
-		} else {
-			v->u.road.state = 0xFF;
-		}
-		return 4;
-	} else if (DirToDiagDir(v->direction) == ReverseDiagDir(dir)) {
-		v->tile = tile;
-		if (v->type == VEH_Train) {
-			if (v->u.rail.track == 0x40) {
-				v->u.rail.track = (DiagDirToAxis(dir) == AXIS_X ? 1 : 2);
-				return 4;
-			}
-		} else {
-			if (v->u.road.state == 0xFF) {
-				v->u.road.state = _road_exit_tunnel_state[dir];
-				v->u.road.frame = 0;
-				return 4;
-			}
-		}
-		return 0;
-	}
-	return 0;
-}
-
-const TileTypeProcs _tile_type_tunnel_procs = {
-	DrawTile_Tunnel,           /* draw_tile_proc */
-	GetSlopeZ_Tunnel,          /* get_slope_z_proc */
-	ClearTile_Tunnel,          /* clear_tile_proc */
-	GetAcceptedCargo_Tunnel,   /* get_accepted_cargo_proc */
-	GetTileDesc_Tunnel,        /* get_tile_desc_proc */
-	GetTileTrackStatus_Tunnel, /* get_tile_track_status_proc */
-	ClickTile_Tunnel,          /* click_tile_proc */
-	AnimateTile_Tunnel,        /* animate_tile_proc */
-	TileLoop_Tunnel,           /* tile_loop_clear */
-	ChangeTileOwner_Tunnel,    /* change_tile_owner_clear */
-	NULL,                            /* get_produced_cargo_proc */
-	VehicleEnter_Tunnel,       /* vehicle_enter_tile_proc */
-	GetSlopeTileh_Tunnel,      /* get_slope_tileh_proc */
-};
-
-const TileTypeProcs _tile_type_bridge_procs = {
-	DrawTile_Bridge,           /* draw_tile_proc */
-	GetSlopeZ_Bridge,          /* get_slope_z_proc */
-	ClearTile_Bridge,          /* clear_tile_proc */
-	GetAcceptedCargo_Bridge,   /* get_accepted_cargo_proc */
-	GetTileDesc_Bridge,        /* get_tile_desc_proc */
-	GetTileTrackStatus_Bridge, /* get_tile_track_status_proc */
-	ClickTile_Bridge,          /* click_tile_proc */
-	AnimateTile_Bridge,        /* animate_tile_proc */
-	TileLoop_Bridge,           /* tile_loop_clear */
-	ChangeTileOwner_Bridge,    /* change_tile_owner_clear */
-	NULL,                      /* get_produced_cargo_proc */
-	VehicleEnter_Bridge,       /* vehicle_enter_tile_proc */
-	GetSlopeTileh_Bridge,      /* get_slope_tileh_proc */
-};