tunnelbridge_cmd.c
author hackykid
Mon, 04 Jul 2005 14:58:55 +0000
changeset 2008 c9d6585c96c8
parent 1981 de031d2aed47
child 2049 ad0d49c916d4
permissions -rw-r--r--
(svn r2516) - Feature: [pbs] Implement path-based-signalling. This allows multiple trains within the same signal block, provided their paths dont intersect. For this the block must have all exit and entry signals be pbs signals. Place these by ctrl-clicking 4 times on a normal signal.
- Feature: [pbs] Implement autoplacement of pbs blocks, when a block has an entry and an exit pbs signal, covert the entire block to pbs. Can be turned off in the patch settings.
- Feature: [pbs] Allow showing of reserved status by making the tracks darker, when the pbs debug level is at least 1.
#include "stdafx.h"
#include "openttd.h"
#include "table/sprites.h"
#include "table/strings.h"
#include "map.h"
#include "tile.h"
#include "vehicle.h"
#include "viewport.h"
#include "command.h"
#include "player.h"
#include "town.h"
#include "sound.h"
#include "pbs.h"
#include "debug.h"

extern void DrawCanalWater(TileIndex tile);

static const byte _bridge_available_year[MAX_BRIDGES] = {
	0, 0, 10, 0, 10, 10, 10, 10, 10, 10, 75, 85, 90
};

static const byte _bridge_minlen[MAX_BRIDGES] = {
	0, 0, 0, 2, 3, 3, 3, 3, 3, 0, 2, 2, 2
};

static const byte _bridge_maxlen[MAX_BRIDGES] = {
	16, 2, 5, 10, 16, 16, 7, 8, 9, 2, 16, 32, 32,
};

const uint16 _bridge_type_price_mod[MAX_BRIDGES] = {
	80, 112, 144, 168, 185, 192, 224, 232, 248, 240, 255, 380, 510,
};

const uint16 _bridge_speeds[MAX_BRIDGES] = {
	0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x0A0, 0x0D0, 0x0F0, 0x100, 0x140, 0x200, 0x260
};

const PalSpriteID _bridge_sprites[MAX_BRIDGES] = {
	0x0A24, 0x31E8A26, 0x0A25, 0x3208A22,
	0x0A22, 0x3218A22, 0x0A23, 0x31C8A23,
	0x31E8A23, 0x0A27, 0x0A28, 0x3218A28,
	0x3238A28,
};

const StringID _bridge_material[MAX_BRIDGES] = {
	STR_5012_WOODEN,
	STR_5013_CONCRETE,
	STR_500F_GIRDER_STEEL,
	STR_5011_SUSPENSION_CONCRETE,
	STR_500E_SUSPENSION_STEEL,
	STR_500E_SUSPENSION_STEEL,
	STR_5010_CANTILEVER_STEEL,
	STR_5010_CANTILEVER_STEEL,
	STR_5010_CANTILEVER_STEEL,
	STR_500F_GIRDER_STEEL,
	STR_5014_TUBULAR_STEEL,
	STR_5014_TUBULAR_STEEL,
	STR_BRIDGE_TUBULAR_SILICON,
};

// 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,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;
	}
}

enum {
	// foundation, whole tile is leveled up (tileh's 7, 11, 13, 14) --> 3 corners raised
	BRIDGE_FULL_LEVELED_FOUNDATION = 1 << 7 | 1 << 11 | 1 << 13 | 1 << 14,
	// foundation, tile is partly leveled up (tileh's 1, 2, 4, 8) --> 1 corner raised
	BRIDGE_PARTLY_LEVELED_FOUNDATION = 1 << 1 | 1 << 2 | 1 << 4 | 1 << 8,
	// no foundations (X,Y direction) (tileh's 0, 3, 6, 9, 12)
	BRIDGE_NO_FOUNDATION = 1 << 0 | 1 << 3 | 1 << 6 | 1 << 9 | 1 << 12,
};

/*	check if bridge can be built on slope
 *	direction 0 = X-axis, direction 1 = Y-axis
 *	is_start_tile = false		<-- end tile
 *	is_start_tile = true		<-- start tile
 */
static uint32 CheckBridgeSlope(uint direction, uint tileh, bool is_start_tile)
{
	if (!(tileh & 0x10)) {	// disable building on very steep slopes

		if (is_start_tile) {
			/* check slope at start tile
					- no extra cost
					- direction X: tiles 0,12
					- direction Y: tiles 0, 9
			*/
			if ((direction?0x201:0x1001) & (1 << tileh))
				return 0;

			// disallow certain start tiles to avoid certain crooked bridges
			if (tileh == 2)
				return CMD_ERROR;

		}
		else {
			/*	check slope at end tile
					- no extra cost
					- direction X: tiles 0, 3
					- direction Y: tiles 0, 6
			*/
			if ((direction?0x41:0x9) & (1 << tileh))
				return 0;

			// disallow certain end tiles to avoid certain crooked bridges
			if (tileh == 8)
				return CMD_ERROR;

		}

		/*	disallow common start/end tiles to avoid certain crooked bridges e.g.
		 *	start-tile:	X 2,1 Y 2,4 (2 was disabled before)
		 *	end-tile:		X 8,4 Y 8,1 (8 was disabled before)
		 */
		if ( (tileh == 1 && (is_start_tile != (bool)direction)) ||
			   (tileh == 4 && (is_start_tile == (bool)direction))    )
			return CMD_ERROR;

		// slope foundations
		if (BRIDGE_FULL_LEVELED_FOUNDATION & (1 << tileh) || BRIDGE_PARTLY_LEVELED_FOUNDATION & (1 << tileh))
			return _price.terraform;
	}

	return CMD_ERROR;
}

uint32 GetBridgeLength(TileIndex begin, TileIndex end)
{
	int x1, y1, x2, y2;	// coordinates of starting and end tiles
	x1 = TileX(begin);
	y1 = TileY(begin);
	x2 = TileX(end);
	y2 = TileY(end);

	return abs((x2 + y2 - x1 - y1)) - 1;
}

bool CheckBridge_Stuff(byte bridge_type, int bridge_len)
{
	int max;	// max possible length of a bridge (with patch 100)

	if (bridge_type >= MAX_BRIDGES) return false;
	if (_bridge_available_year[bridge_type] > _cur_year) return false;

	max = _bridge_maxlen[bridge_type];
	if (max >= 16 && _patches.longbridges)
		max = 100;

	if (bridge_len < _bridge_minlen[bridge_type] || bridge_len > max) return false;

	return true;
}

/** Build a Bridge
 * @param x,y end tile coord
 * @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(int x, int y, uint32 flags, uint32 p1, uint32 p2)
{
	int bridge_type;
	byte rail_or_road, railtype, m5;
	int sx,sy;
	TileInfo ti_start, ti_end, ti; /* OPT: only 2 of those are ever used */
	int bridge_len, odd_middle_part;
	uint direction;
	int i;
	int32 cost, terraformcost, ret;
	bool allow_on_slopes;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	/* unpack parameters */
	bridge_type = p2 & 0xFF;
	railtype = (byte)(p2 >> 8);

	if (p1 > MapSize()) return CMD_ERROR;

	// type of bridge
	if (HASBIT(railtype, 7)) { // bit 15 of original p2 param
		railtype = 0;
		rail_or_road = 2;
	} else {
		if (!ValParamRailtype(railtype)) return CMD_ERROR;
		rail_or_road = 0;
	}

	sx = TileX(p1) * 16;
	sy = TileY(p1) * 16;

	direction = 0;

	/* 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 = 1;
		if (y > sy) {
			intswap(y,sy);
			intswap(x,sx);
		}
	} else if (y == sy) {
		if (x > sx) {
			intswap(y,sy);
			intswap(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) >> 4) - 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 */
	if (
		((FindLandscapeHeight(&ti_end, sx, sy),
			ti_end.type == MP_WATER) && ti_end.map5 == 0) ||
		((FindLandscapeHeight(&ti_start, x, y),
			ti_start.type == MP_WATER) && ti_start.map5 == 0))
		return_cmd_error(STR_02A0_ENDS_OF_BRIDGE_MUST_BOTH);

	if (BRIDGE_FULL_LEVELED_FOUNDATION & (1 << ti_start.tileh)) {
		ti_start.z += 8;
		ti_start.tileh = 0;
	}

	if (BRIDGE_FULL_LEVELED_FOUNDATION & (1 << ti_end.tileh)) {
		ti_end.z += 8;
		ti_end.tileh = 0;
	}

	if (ti_start.z != ti_end.z)
		return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);

	_error_message = STR_500C;


	// Towns are not allowed to use bridges on slopes.
	allow_on_slopes = ((!_is_ai_player || _patches.ainew_active)
	                   && _current_player != OWNER_TOWN && _patches.build_on_slopes);

	/* Try and clear the start landscape */

	if (CmdFailed(ret = DoCommandByTile(ti_start.tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR)))
		return CMD_ERROR;
	cost = ret;

	// true - bridge-start-tile, false - bridge-end-tile
	terraformcost = CheckBridgeSlope(direction, ti_start.tileh, true);
	if (terraformcost == CMD_ERROR || (terraformcost && !allow_on_slopes))
		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
	cost += terraformcost;

	/* Try and clear the end landscape */

	if (CmdFailed(ret = DoCommandByTile(ti_end.tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR)))
		return CMD_ERROR;
	cost += ret;

	// false - end tile slope check
	terraformcost = CheckBridgeSlope(direction, ti_end.tileh, false);
	if (terraformcost == CMD_ERROR || (terraformcost && !allow_on_slopes))
		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
	cost += terraformcost;


	/* do the drill? */
	if (flags & DC_EXEC) {
		/* build the start tile */
		ModifyTile(ti_start.tile,
			MP_SETTYPE(MP_TUNNELBRIDGE) |
			MP_MAP2 | MP_MAP3LO | MP_MAPOWNER_CURRENT | MP_MAP5,
			(bridge_type << 4), /* map2 */
			railtype, /* map3_lo */
			0x80 | direction | rail_or_road /* map5 */
		);

		/* build the end tile */
		ModifyTile(ti_end.tile,
			MP_SETTYPE(MP_TUNNELBRIDGE) |
			MP_MAP2 | MP_MAP3LO | MP_MAPOWNER_CURRENT | MP_MAP5,
			(bridge_type << 4), /* map2 */
			railtype, /* map3_lo */
			0x80 | 0x20 | direction | rail_or_road /* map5 */
		);
	}

	// position of middle part of the odd bridge (larger than MAX(i) otherwise)
	odd_middle_part = (bridge_len % 2) ? (bridge_len / 2) : bridge_len;

	for (i = 0; i != bridge_len; i++) {
		if (direction != 0) {
			y += 16;
		} else
			x += 16;

		FindLandscapeHeight(&ti, x, y);

		_error_message = STR_5009_LEVEL_LAND_OR_WATER_REQUIRED;
		if (ti.tileh != 0 && ti.z >= ti_start.z)
			return CMD_ERROR;

		// Find ship below
		if ( ti.type == MP_WATER && !EnsureNoVehicle(ti.tile) )
		{
			_error_message = STR_980E_SHIP_IN_THE_WAY;
			return CMD_ERROR;
		}

		if (ti.type == MP_WATER) {
			if (ti.map5 > 1) goto not_valid_below;
			m5 = 0xC8;
		} else if (ti.type == MP_RAILWAY) {
			if (direction == 0) {
				if (ti.map5 != 2) goto not_valid_below;
			} else {
				if (ti.map5 != 1) goto not_valid_below;
			}
			m5 = 0xE0;
		} else if (ti.type == MP_STREET) {
			if (direction == 0) {
				if (ti.map5 != 5) goto not_valid_below;
			} else {
				if (ti.map5 != 10) goto not_valid_below;
			}
			m5 = 0xE8;
		} else {
not_valid_below:;
			/* try and clear the middle landscape */
			if (CmdFailed(ret = DoCommandByTile(ti.tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR)))
				return CMD_ERROR;
			cost += ret;
			m5 = 0xC0;
		}

		/* do middle part of bridge */
		if (flags & DC_EXEC) {
			_map5[ti.tile] = (byte)(m5 | direction | rail_or_road);
			SetTileType(ti.tile, MP_TUNNELBRIDGE);

			//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 - alwats 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)

			if(i==0)                    //first tile
				m5 = 0;
			else if (i==bridge_len-1)   //last tile
				m5 = 1;
			else if(i==odd_middle_part) //we are on the middle of odd bridge: #5 on even pos, #4 on odd
				m5 = 5 - (i%2);
			else {
					// generate #2 and #3 in turns [i%2==0], after the middle of odd bridge
					// this sequence swaps [... XOR (i>odd_middle_part)],
					// for even bridges XOR does not apply as odd_middle_part==bridge_len
					m5 = 2 + ((i%2==0)^(i>odd_middle_part));
			}

			_map2[ti.tile] = (bridge_type << 4) | m5;
			_map3_lo[ti.tile] &= 0xF;
			_map3_lo[ti.tile] |= (byte)(railtype << 4);

			MarkTileDirtyByTile(ti.tile);
		}
	}

	SetSignalsOnBothDir(ti_start.tile, (direction&1) ? 1 : 0);

	/*	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)) {
		bridge_len += 2;	// begin and end tiles/ramps

		if (_current_player < MAX_PLAYERS && !(_is_ai_player && !_patches.ainew_active))
			bridge_len = CalcBridgeLenCostFactor(bridge_len);

		cost += ((int64)bridge_len * _price.build_bridge * _bridge_type_price_mod[bridge_type]) >> 8;
	}

	return cost;
}

static bool DoCheckTunnelInWay(TileIndex tile, uint z, uint dir)
{
	TileIndexDiff delta = TileOffsByDir(dir);
	TileInfo ti;

	do {
		tile -= delta;
		FindLandscapeHeightByTile(&ti, tile);
	} while (z < ti.z);

	if (z == ti.z && ti.type == MP_TUNNELBRIDGE && (ti.map5&0xF0) == 0 && (ti.map5&3) == dir) {
		_error_message = STR_5003_ANOTHER_TUNNEL_IN_THE_WAY;
		return false;
	}

	return true;
}

bool CheckTunnelInWay(TileIndex tile, int z)
{
	return DoCheckTunnelInWay(tile,z,0) &&
		DoCheckTunnelInWay(tile,z,1) &&
		DoCheckTunnelInWay(tile,z,2) &&
		DoCheckTunnelInWay(tile,z,3);
}

static byte _build_tunnel_bh;
static byte _build_tunnel_railtype;

static int32 DoBuildTunnel(int x, int y, int x2, int y2, uint32 flags, uint exc_tile)
{
	TileIndex end_tile;
	int direction;
	int32 cost, ret;
	TileInfo ti;
	uint z;

	if ((uint)x > MapMaxX() * 16 - 1 || (uint)y > MapMaxY() * 16 - 1)
		return CMD_ERROR;

	/* check if valid, and make sure that (x,y) is smaller than (x2,y2) */
	direction = 0;
	if (x == x2) {
		if (y == y2)
			return_cmd_error(STR_5008_CANNOT_START_AND_END_ON);
		direction++;
		if (y > y2) {
			intswap(y,y2);
			intswap(x,x2);
			exc_tile|=2;
		}
	} else if (y == y2) {
		if (x > x2) {
			intswap(y,y2);
			intswap(x,x2);
			exc_tile|=2;
		}
	} else
		return_cmd_error(STR_500A_START_AND_END_MUST_BE_IN);

	cost = 0;

	FindLandscapeHeight(&ti, x2, y2);
	end_tile = ti.tile;
	z = ti.z;

	if (exc_tile != 3) {
		if ( (direction ? 9U : 12U) != ti.tileh)
			return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
		ret = DoCommandByTile(ti.tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
		if (CmdFailed(ret)) return CMD_ERROR;
		cost += ret;
	}
	cost += _price.build_tunnel;

	for(;;) {
		if (direction) y2-=16; else x2-=16;

		if (x2 == x && y2 == y)
			break;

		FindLandscapeHeight(&ti, x2, y2);
		if (ti.z <= z)
			return_cmd_error(STR_5002);

		if (!_cheats.crossing_tunnels.value && !CheckTunnelInWay(ti.tile, z))
			return CMD_ERROR;

		cost += _price.build_tunnel;
		cost += (cost >> 3);

		if (cost >= 400000000)
			cost = 400000000;
	}

	FindLandscapeHeight(&ti, x2, y2);
	if (ti.z != z)
		return_cmd_error(STR_5004);

	if (exc_tile != 1) {
		if ( (direction ? 6U : 3U) != ti.tileh)
			return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);

		ret = DoCommandByTile(ti.tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
		if (CmdFailed(ret)) return CMD_ERROR;
		cost += ret;
	}

	if (flags & DC_EXEC) {
		ModifyTile(ti.tile,
			MP_SETTYPE(MP_TUNNELBRIDGE) |
			MP_MAP3LO | MP_MAPOWNER_CURRENT | MP_MAP5,
			_build_tunnel_railtype, /* map3lo */
			((_build_tunnel_bh << 1) | 2) - direction /* map5 */
		);

		ModifyTile(end_tile,
			MP_SETTYPE(MP_TUNNELBRIDGE) |
			MP_MAP3LO | MP_MAPOWNER_CURRENT | MP_MAP5,
			_build_tunnel_railtype, /* map3lo */
			(_build_tunnel_bh << 1) | (direction ? 3:0)/* map5 */
		);

		UpdateSignalsOnSegment(end_tile, direction?7:1);
	}

	return cost + _price.build_tunnel;
}

/** Build Tunnel.
 * @param x,y start tile coord of tunnel
 * @param p1 railtype, 0x200 for road tunnel
 * @param p2 unused (XXX - ptr to uint that recieves end tile; wtf?????)
 */
int32 CmdBuildTunnel(int x, int y, uint32 flags, uint32 p1, uint32 p2)
{
	TileInfo ti, tiorg;
	int direction;
	uint z;
	static const int8 _build_tunnel_coord_mod[4+1] = { -16, 0, 16, 0, -16 };
	static const byte _build_tunnel_tileh[4] = {3, 9, 12, 6};
	TileIndex excavated_tile;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	if (p1 != 0x200 && !ValParamRailtype(p1)) return CMD_ERROR;

	_build_tunnel_railtype = (byte)(p1 & 0xFF);
	_build_tunnel_bh = (byte)(p1 >> 8);

	_build_tunnel_endtile = 0;
	excavated_tile = 0;

	FindLandscapeHeight(&tiorg, x, y);

	if (!EnsureNoVehicle(tiorg.tile))
		return CMD_ERROR;

	if (!(direction=0, tiorg.tileh==12) &&
			!(direction++, tiorg.tileh==6) &&
			!(direction++, tiorg.tileh==3) &&
			!(direction++, tiorg.tileh==9) )
		return_cmd_error(STR_500B_SITE_UNSUITABLE_FOR_TUNNEL);

	z = tiorg.z;
	do {
		x += _build_tunnel_coord_mod[direction];
		y += _build_tunnel_coord_mod[direction+1];
		FindLandscapeHeight(&ti, x, y);
	} while (z != ti.z);
	_build_tunnel_endtile = ti.tile;


	if (!EnsureNoVehicle(ti.tile))
		return CMD_ERROR;

	if (ti.tileh != _build_tunnel_tileh[direction]) {
		if (CmdFailed(DoCommandByTile(ti.tile, ti.tileh & ~_build_tunnel_tileh[direction], 0, flags, CMD_TERRAFORM_LAND)))
			return_cmd_error(STR_5005_UNABLE_TO_EXCAVATE_LAND);
		excavated_tile = 1;
	}

	return DoBuildTunnel(x, y, tiorg.x, tiorg.y, flags, excavated_tile);
}

TileIndex CheckTunnelBusy(TileIndex tile, uint *length)
{
	uint z = GetTileZ(tile);
	byte m5 = _map5[tile];
	int delta = TileOffsByDir(m5 & 3);
	uint len = 0;
	TileIndex starttile = tile;
	Vehicle *v;

	do {
		tile += delta;
		len++;
	} while (
		!IsTileType(tile, MP_TUNNELBRIDGE) ||
		(_map5[tile] & 0xF0) != 0 ||
		(byte)(_map5[tile] ^ 2) != m5 ||
		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 int32 DoClearTunnel(TileIndex tile, uint32 flags)
{
	Town *t;
	TileIndex endtile;
	uint length;
	static const byte _updsignals_tunnel_dir[4] = { 5, 7, 1, 3};

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	// in scenario editor you can always destroy tunnels
	if (_game_mode != GM_EDITOR && !CheckTileOwnership(tile)) {
		if (!(_patches.extra_dynamite || _cheats.magic_bulldozer.value) || !IsTileOwner(tile, OWNER_TOWN))
			return CMD_ERROR;
	}

	endtile = CheckTunnelBusy(tile, &length);
	if (endtile == INVALID_TILE) return CMD_ERROR;

	_build_tunnel_endtile = endtile;

	t = ClosestTownFromTile(tile, (uint)-1); //needed for town rating penalty
	// check if you're allowed to remove the tunnel owned by a town
	// removal allowal depends on difficulty settings
	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
		if (!CheckforTownRating(tile, 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!! ;)
		byte tile_dir = _map5[tile]&3;
		byte endtile_dir = _map5[endtile]&3;
		DoClearSquare(tile);
		DoClearSquare(endtile);
		UpdateSignalsOnSegment(tile, _updsignals_tunnel_dir[tile_dir]);
		UpdateSignalsOnSegment(endtile, _updsignals_tunnel_dir[endtile_dir]);
		if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR)
			ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM);
	}
	return  _price.clear_tunnel * (length + 1);
}

static TileIndex FindEdgesOfBridge(TileIndex tile, TileIndex *endtile)
{
	int direction = _map5[tile] & 1;
	TileIndex start;

	// find start of bridge
	for(;;) {
		if (IsTileType(tile, MP_TUNNELBRIDGE) && (_map5[tile] & 0xE0) == 0x80)
			break;
		tile += direction ? TileDiffXY(0, -1) : TileDiffXY(-1, 0);
	}

	start = tile;

	// find end of bridge
	for(;;) {
		if (IsTileType(tile, MP_TUNNELBRIDGE) && (_map5[tile] & 0xE0) == 0xA0)
			break;
		tile += direction ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	}

	*endtile = tile;

	return start;
}

static int32 DoClearBridge(TileIndex tile, uint32 flags)
{
	TileIndex endtile;
	Vehicle *v;
	Town *t;
	int direction;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	direction = _map5[tile]&1;

	/* delete stuff under the middle part if there's a transport route there..? */
	if ((_map5[tile] & 0xE0) == 0xE0) {
		int32 cost;

		// check if we own the tile below the bridge..
		if (_current_player != OWNER_WATER && (!CheckTileOwnership(tile) || !EnsureNoVehicleZ(tile, TilePixelHeight(tile))))
			return CMD_ERROR;

		cost = (_map5[tile] & 8) ? _price.remove_road * 2 : _price.remove_rail;

		if (flags & DC_EXEC) {
			_map5[tile] = _map5[tile] & ~0x38;
			SetTileOwner(tile, OWNER_NONE);
			MarkTileDirtyByTile(tile);
		}
		return cost;

	/* delete canal under bridge */
	} else if ((_map5[tile] & 0xC8) == 0xC8 && TilePixelHeight(tile) != 0) {
		int32 cost;

		// check for vehicles under bridge
		if (!EnsureNoVehicleZ(tile, TilePixelHeight(tile)))
			return CMD_ERROR;
		cost = _price.clear_water;
		if (flags & DC_EXEC) {
			_map5[tile] = _map5[tile] & ~0x38;
			SetTileOwner(tile, OWNER_NONE);
			MarkTileDirtyByTile(tile);
		}
		return cost;
	}

	tile = FindEdgesOfBridge(tile, &endtile);

	// floods, scenario editor can always destroy bridges
	if (_current_player != OWNER_WATER && _game_mode != GM_EDITOR && !CheckTileOwnership(tile)) {
		if (!(_patches.extra_dynamite || _cheats.magic_bulldozer.value) || !IsTileOwner(tile, OWNER_TOWN))
			return CMD_ERROR;
	}

	if (!EnsureNoVehicle(tile) || !EnsureNoVehicle(endtile))
		return CMD_ERROR;

	/*	Make sure there's no vehicle on the bridge
			Omit tile and endtile, since these are already checked, thus solving the problem
			of bridges over water, or higher bridges, where z is not increased, eg level bridge
	*/
	tile		+= direction ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	endtile	-= direction ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	/* Bridges on slopes might have their Z-value offset..correct this */
	if ((v = FindVehicleBetween(tile, endtile, TilePixelHeight(tile) + 8 + GetCorrectTileHeight(tile))) != NULL) {
		VehicleInTheWayErrMsg(v);
		return CMD_ERROR;
	}

	/* Put the tiles back to start/end position */
	tile		-= direction ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	endtile	+= direction ? TileDiffXY(0, 1) : TileDiffXY(1, 0);


	t = ClosestTownFromTile(tile, (uint)-1); //needed for town rating penalty
	// check if you're allowed to remove the bridge owned by a town.
	// removal allowal depends on difficulty settings
	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
		if (!CheckforTownRating(tile, flags, t, TUNNELBRIDGE_REMOVE))
			return CMD_ERROR;
	}

	if (flags & DC_EXEC) {
		byte m5;
		uint c = tile;
		uint16 new_data;
		byte pbs;

		//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);

		do {
			m5 = _map5[c];
			pbs = PBSTileReserved(c);

			if (m5 & 0x40) {
				if (m5 & 0x20) {
					static const uint16 _new_data_table[] = {0x1002, 0x1001, 0x2005, 0x200A, 0, 0, 0, 0};
					new_data = _new_data_table[((m5 & 0x18) >> 2) | (m5&1)];
				}	else {
					if (!(m5 & 0x18)) goto clear_it;
					new_data = (GetTileSlope(c, NULL) == 0) ? 0x6000 : 0x6001;
				}

				SetTileType(c, new_data >> 12);
				_map5[c] = (byte)new_data;
				_map2[c] = 0;
				_map3_hi[c] &= 0x0F;
				if (direction ? HASBIT(pbs,0) : HASBIT(pbs,1))
					PBSReserveTrack(c, direction ? 0 : 1);

				MarkTileDirtyByTile(c);

			} else {
clear_it:;
				DoClearSquare(c);
			}
			c += direction ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
		} while (c <= endtile);

		SetSignalsOnBothDir(tile, direction);
		SetSignalsOnBothDir(endtile, direction);

	}

	return ((((endtile - tile) >> (direction?8:0))&0xFF)+1) * _price.clear_bridge;
}

static int32 ClearTile_TunnelBridge(TileIndex tile, byte flags)
{
	byte m5 = _map5[tile];

	if ((m5 & 0xF0) == 0) {
		if (flags & DC_AUTO)
			return_cmd_error(STR_5006_MUST_DEMOLISH_TUNNEL_FIRST);

		return DoClearTunnel(tile, flags);
	} else if (m5 & 0x80) {
		if (flags & DC_AUTO)
			return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);

		return DoClearBridge(tile, flags);
	}

	return CMD_ERROR;
}

int32 DoConvertTunnelBridgeRail(TileIndex tile, uint totype, bool exec)
{
	TileIndex endtile;
	uint length;
	Vehicle *v;

	if ((_map5[tile] & 0xFC) == 0x00) {
		// railway tunnel
		if (!CheckTileOwnership(tile)) return CMD_ERROR;

		if ( (uint)(_map3_lo[tile] & 0xF) == totype) return CMD_ERROR;

		endtile = CheckTunnelBusy(tile, &length);
		if (endtile == INVALID_TILE) return CMD_ERROR;

		if (exec) {
			_map3_lo[tile] = (_map3_lo[tile] & 0xF0) + totype;
			_map3_lo[endtile] = (_map3_lo[endtile] & 0xF0) + totype;
			MarkTileDirtyByTile(tile);
			MarkTileDirtyByTile(endtile);
		}
		return (length + 1) * (_price.build_rail >> 1);
	} else if ((_map5[tile] & 0xF8) == 0xE0) {
		// bridge middle part with rail below
		// only check for train under bridge
		if (!CheckTileOwnership(tile) || !EnsureNoVehicleZ(tile, TilePixelHeight(tile)))
			return CMD_ERROR;

		// tile is already of requested type?
		if ( (uint)(_map3_lo[tile] & 0xF) == totype) return CMD_ERROR;
		// change type.
		if (exec) {
			_map3_lo[tile] = (_map3_lo[tile] & 0xF0) + totype;
			MarkTileDirtyByTile(tile);
		}
		return _price.build_rail >> 1;
	} else if ((_map5[tile]&0xC6) == 0x80) {
		TileIndex starttile;
		int32 cost;
		uint z = TilePixelHeight(tile);

		z += 8;

		if (!CheckTileOwnership(tile)) return CMD_ERROR;

		// railway bridge
		starttile = tile = FindEdgesOfBridge(tile, &endtile);
		// Make sure there's no vehicle on the bridge
		if ((v=FindVehicleBetween(tile, endtile, z)) != NULL) {
			VehicleInTheWayErrMsg(v);
			return CMD_ERROR;
		}

		if (!EnsureNoVehicle(starttile) || !EnsureNoVehicle(endtile)) {
			_error_message = STR_8803_TRAIN_IN_THE_WAY;
			return CMD_ERROR;
		}

		if ( (uint)(_map3_lo[tile] & 0xF) == totype) return CMD_ERROR;
		cost = 0;
		do {
			if (exec) {
				if (tile == starttile || tile == endtile) {
					_map3_lo[tile] = (_map3_lo[tile] & 0xF0) + totype;
				} else {
					_map3_lo[tile] = (_map3_lo[tile] & 0x0F) + (totype << 4);
				}
				MarkTileDirtyByTile(tile);
			}
			cost += (_price.build_rail>>1);
			tile += _map5[tile] & 1 ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
		} while (tile <= endtile);

		return cost;
	} else
		return CMD_ERROR;
}


// fast routine for getting the height of a middle bridge tile. 'tile' MUST be a middle bridge tile.
static uint GetBridgeHeight(const TileInfo *ti)
{
	TileIndexDiff delta;
	TileIndex tile = ti->tile;

	// find the end tile of the bridge.
	delta = (_map5[tile] & 1) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	do {
		assert((_map5[tile] & 0xC0) == 0xC0);	// bridge and middle part
		tile += delta;
	} while (_map5[tile] & 0x40);	// while bridge middle parts

	/* Return the height there (the height of the NORTH CORNER)
	 * If the end of the bridge is on a tileh 7 (all raised, except north corner),
	 * the z coordinate is 1 height level too low. Compensate for that */
	return TilePixelHeight(tile) + (GetTileSlope(tile, NULL) == 7 ? 8 : 0);
}

static const byte _bridge_foundations[2][16] = {
// 0 1  2  3  4 5 6 7  8 9 10 11 12 13 14 15
	{1,16,18,3,20,5,0,7,22,0,10,11,12,13,14},
	{1,15,17,0,19,5,6,7,21,9,10,11, 0,13,14},
};

extern const byte _road_sloped_sprites[14];

#include "table/track_land.h"
#include "table/bridge_land.h"
#include "table/tunnel_land.h"
#include "table/water_land.h"

static void DrawBridgePillars(TileInfo *ti, int x, int y, int z)
{
	const uint32 *b;
	uint32 image;
	int piece;

	b = _bridge_poles_table[_map2[ti->tile]>>4];

	// Draw first piece
	// (necessary for cantilever bridges)
	image = b[12 + (ti->map5&0x01)];
	piece = _map2[ti->tile]&0xF;
	if (image != 0 && piece != 0) {
		if (_display_opt & DO_TRANS_BUILDINGS) image = (image & 0x3FFF) | 0x03224000;
		DrawGroundSpriteAt(image, x, y, z);
	}

	image = b[(ti->map5&0x01)*6 + piece];

	if (image != 0) {
		int back_height, front_height, i=z;
		const byte *p;

		static const byte _tileh_bits[4][8] = {
			{2,1,8,4,  16,11,0,9},
			{1,8,4,2,  11,16,9,0},
			{4,8,1,2,  16,11,0,9},
			{2,4,8,1,  11,16,9,0},
		};

		if (_display_opt & DO_TRANS_BUILDINGS) image = (image & 0x3FFF) | 0x03224000;

		p = _tileh_bits[(image & 1) * 2 + (ti->map5&0x01)];
		front_height = ti->z + ((ti->tileh & p[0])?8:0);
		back_height = ti->z + ((ti->tileh & p[1])?8:0);
		if (ti->tileh & 0x10) {
			if (!(ti->tileh & p[2])) front_height += 8;
			if (!(ti->tileh & p[3])) back_height += 8;
		}

		for(; z>=front_height || z>=back_height; z=z-8) {
			if (z>=front_height) AddSortableSpriteToDraw(image, x,y, p[4], p[5], 0x28, z); // front facing pillar
			if (z>=back_height && z<i-8) AddSortableSpriteToDraw(image, x - p[6], y - p[7], p[4], p[5], 0x28, z); // back facing pillar
		}
	}
}

uint GetBridgeFoundation(uint tileh, byte direction) {
	int i;
	// normal level sloped building (7, 11, 13, 14)
	if (BRIDGE_FULL_LEVELED_FOUNDATION & (1 << tileh))
		return tileh;

	// inclined sloped building
	if (	((i=0, tileh == 1) || (i+=2, tileh == 2) || (i+=2, tileh == 4) || (i+=2, tileh == 8)) &&
				( direction == 0 || (i++, direction == 1)) )
		return i + 15;

	return 0;
}

static void DrawTile_TunnelBridge(TileInfo *ti)
{
	uint32 image;
	uint tmp;
	const uint32 *b;
	bool ice = _map3_hi[ti->tile] & 0x80;

	// draw tunnel?
	if ( (byte)(ti->map5&0xF0) == 0) {
		/* railway type */
		image = (_map3_lo[ti->tile] & 0xF) * 8;

		/* ice? */
		if (ice)
			image += 32;

		image += _draw_tunnel_table_1[(ti->map5 >> 2) & 0x3];
		image += (ti->map5 & 3) << 1;
		DrawGroundSprite(image);

		AddSortableSpriteToDraw(image+1, ti->x + 15, ti->y + 15, 1, 1, 8, (byte)ti->z);
	// draw bridge?
	} else if ((byte)ti->map5 & 0x80) {
		// get type of track on the bridge.
		tmp = _map3_lo[ti->tile];
		if (ti->map5 & 0x40) tmp >>= 4;
		tmp &= 0xF;

		// 0 = rail bridge
		// 1 = road bridge
		// 2 = monorail bridge
		// 3 = maglev bridge

		// add direction and fix stuff.
		if (tmp != 0) tmp++;
		tmp = (ti->map5&3) + (tmp*2);

		if (!(ti->map5 & 0x40)) {	// bridge ramps

			if (!(BRIDGE_NO_FOUNDATION & (1 << ti->tileh))) {	// no foundations for 0, 3, 6, 9, 12
				int f = GetBridgeFoundation(ti->tileh, ti->map5 & 0x1);	// pass direction
				if (f) DrawFoundation(ti, f);

				// default sloped sprites..
				if (ti->tileh != 0) image = _track_sloped_sprites[ti->tileh - 1] + 0x3F3;
			}

			// bridge ending.
			b = _bridge_sprite_table[(_map2[ti->tile] >> 4) & 0xF][6];
			b += (tmp&(3<<1))*4; /* actually ((tmp>>2)&3)*8 */
			b += (tmp&1); // direction
			if (ti->tileh == 0) b += 4; // sloped "entrance" ?
			if (ti->map5 & 0x20) b += 2; // which side

			image = *b;

			if (!ice) {
				DrawClearLandTile(ti, 3);
			} else {
				DrawGroundSprite(0x11C6 + _tileh_to_sprite[ti->tileh]);
			}

			// draw ramp
			if (_display_opt & DO_TRANS_BUILDINGS) image = (image & 0x3FFF) | 0x03224000;
			AddSortableSpriteToDraw(image, ti->x, ti->y, 16, 16, 7, ti->z);
		} else {
			// bridge middle part.
			uint z;
			int x,y;

			image = (ti->map5 >> 3) & 3;	// type of stuff under bridge (only defined for 0,1)
			assert(image <= 1);

			if (!(ti->map5 & 0x20)) {
				// draw land under bridge
				if (ice) image += 2;					// ice too?

				if (image != 1 || ti->tileh == 0)
					DrawGroundSprite(_bridge_land_below[image] + _tileh_to_sprite[ti->tileh]);
				else
					DrawGroundSprite(_water_shore_sprites[ti->tileh]);

				// draw canal water?
				if (ti->map5 & 8 && ti->z != 0) DrawCanalWater(ti->tile);
			} else {
				// draw transport route under bridge

				// draw foundation?
				if (ti->tileh) {
					int f = _bridge_foundations[ti->map5&1][ti->tileh];
					if (f) DrawFoundation(ti, f);
				}

				if (!(image&1)) {
					// railway
					image = 0x3F3 + (ti->map5 & 1);
					if (ti->tileh != 0) image = _track_sloped_sprites[ti->tileh - 1] + 0x3F3;
					image += (_map3_lo[ti->tile] & 0xF) * TRACKTYPE_SPRITE_PITCH;
					if (ice) image += 26; // ice?
				} else {
					// road
					image = 1332 + (ti->map5 & 1);
					if (ti->tileh != 0) image = _road_sloped_sprites[ti->tileh - 1] + 0x53F;
					if (ice) image += 19; // ice?
				}
				DrawGroundSprite(image);
			}
			// get bridge sprites
			b = _bridge_sprite_table[(_map2[ti->tile] >> 4) & 0xF][_map2[ti->tile]&0xF] + tmp * 4;

			z = GetBridgeHeight(ti) + 5;

			// draw rail
			image = b[0];
			if (_display_opt & DO_TRANS_BUILDINGS) image = (image & 0x3FFF) | 0x03224000;
			AddSortableSpriteToDraw(image, ti->x, ti->y, (ti->map5&1)?11:16, (ti->map5&1)?16:11, 1, z);

			x = ti->x;
			y = ti->y;
			image = b[1];
			if (_display_opt & DO_TRANS_BUILDINGS) image = (image & 0x3FFF) | 0x03224000;

			// draw roof
			if (ti->map5&1) {
				x += 12;
				if (image&0x3FFF) AddSortableSpriteToDraw(image, x,y, 1, 16, 0x28, z);
			} else {
				y += 12;
				if (image&0x3FFF) AddSortableSpriteToDraw(image, x,y, 16, 1, 0x28, z);
			}

			if (ti->z + 5 == z ) {
				// draw poles below for small bridges
				image = b[2];
				if (image) {
					if (_display_opt & DO_TRANS_BUILDINGS) image = (image & 0x3FFF) | 0x03224000;
					DrawGroundSpriteAt(image, x, y, z);
				}
			} else if (_patches.bridge_pillars) {
				// draw pillars below for high bridges
				DrawBridgePillars(ti, x, y, z);
			}
		}
	}

	if (_debug_pbs_level >= 1) {
		byte pbs = PBSTileReserved(ti->tile);
		if (pbs & TRACK_BIT_DIAG1) DrawGroundSprite(0x3ED | PALETTE_CRASH);
		if (pbs & TRACK_BIT_DIAG2) DrawGroundSprite(0x3EE | PALETTE_CRASH);
		if (pbs & TRACK_BIT_UPPER) DrawGroundSprite(0x3EF | PALETTE_CRASH);
		if (pbs & TRACK_BIT_LOWER) DrawGroundSprite(0x3F0 | PALETTE_CRASH);
		if (pbs & TRACK_BIT_LEFT)  DrawGroundSprite(0x3F2 | PALETTE_CRASH);
		if (pbs & TRACK_BIT_RIGHT) DrawGroundSprite(0x3F1 | PALETTE_CRASH);
	}
}

static uint GetSlopeZ_TunnelBridge(TileInfo *ti) {
	uint z = ti->z;
	uint x = ti->x & 0xF;
	uint y = ti->y & 0xF;

	// swap directions if Y tunnel/bridge to let the code handle the X case only.
	if (ti->map5 & 1) uintswap(x,y);

	// to the side of the tunnel/bridge?
	if (IS_INT_INSIDE(y, 5, 10+1)) {
		// tunnel?
		if ( (ti->map5 & 0xF0) == 0)
			return z;

		// bridge?
		if ( ti->map5 & 0x80 ) {
			// bridge ending?
			if (!(ti->map5 & 0x40)) {
				if (BRIDGE_FULL_LEVELED_FOUNDATION & (1 << ti->tileh))	// 7, 11, 13, 14
					z += 8;

				// no ramp for bridge ending
				if ((BRIDGE_PARTLY_LEVELED_FOUNDATION & (1 << ti->tileh) || BRIDGE_NO_FOUNDATION & (1 << ti->tileh)) && ti->tileh != 0) {
					return z + 8;

				} else if (!(ti->map5 & 0x20)) { // northern / southern ending
					// ramp
					return (z + (x>>1) + 1);
				} else {
					// ramp in opposite dir
					return (z + ((x^0xF)>>1));
				}

			// bridge middle part
			} else {
				// build on slopes?
				if (ti->tileh) z+=8;

				// keep the same elevation because we're on the bridge?
				if (_get_z_hint >= z + 8)
					return _get_z_hint;

				// actually on the bridge, but not yet in the shared area.
				if (!IS_INT_INSIDE(x, 5, 10+1))
					return GetBridgeHeight(ti) + 8;

				// in the shared area, assume that we're below the bridge, cause otherwise the hint would've caught it.
				// if rail or road below then it means it's possibly build on slope below the bridge.
				if (ti->map5 & 0x20) {
					uint f = _bridge_foundations[ti->map5&1][ti->tileh];
					// make sure that the slope is not inclined foundation
					if (IS_BYTE_INSIDE(f, 1, 15)) return z;

					// change foundation type?
					if (f) ti->tileh = _inclined_tileh[f - 15];
				}

				// no transport route, fallback to default
			}
		}
	} else {
		// if it's a bridge middle with transport route below, then we need to compensate for build on slopes
		if ( (ti->map5 & (0x80 + 0x40 + 0x20)) == (0x80 + 0x40 + 0x20)) {
			uint f;
			if (ti->tileh) z += 8;
			f = _bridge_foundations[ti->map5&1][ti->tileh];
			if (IS_BYTE_INSIDE(f, 1, 15)) return z;
			if (f) ti->tileh = _inclined_tileh[f - 15];
		}
	}

	// default case
	z = ti->z;
	return GetPartialZ(ti->x&0xF, ti->y&0xF, ti->tileh) + z;
}

static uint GetSlopeTileh_TunnelBridge(TileInfo *ti) {
	// not accurate, but good enough for slope graphics drawing
	return 0;
}


static void GetAcceptedCargo_TunnelBridge(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_TunnelBridge(TileIndex tile, TileDesc *td)
{
	if ((_map5[tile] & 0x80) == 0) {
		td->str = STR_5017_RAILROAD_TUNNEL + ((_map5[tile] >> 2) & 3);
	} else {
		td->str = _bridge_tile_str[ (_map2[tile] >> 4) + (((_map5[tile]>>1)&3)<<4) ];

		/* scan to the end of the bridge, that's where the owner is stored */
		if (_map5[tile] & 0x40) {
			TileIndexDiff delta = _map5[tile] & 1 ? TileDiffXY(0, -1) : TileDiffXY(-1, 0);

			do tile += delta; while (_map5[tile] & 0x40);
		}
	}
	td->owner = GetTileOwner(tile);
}


static void AnimateTile_TunnelBridge(TileIndex tile)
{
	/* not used */
}

static void TileLoop_TunnelBridge(TileIndex tile)
{
	if (_opt.landscape == LT_HILLY) {
		if ( GetTileZ(tile) > _opt.snow_line) {
			if (!(_map3_hi[tile] & 0x80)) {
				_map3_hi[tile] |= 0x80;
				MarkTileDirtyByTile(tile);
			}
		} else {
			if (_map3_hi[tile] & 0x80) {
				_map3_hi[tile] &= ~0x80;
				MarkTileDirtyByTile(tile);
			}
		}
	} else if (_opt.landscape == LT_DESERT) {
		if (GetMapExtraBits(tile) == 1 && !(_map3_hi[tile]&0x80)) {
			_map3_hi[tile] |= 0x80;
			MarkTileDirtyByTile(tile);
		}
	}

	// if it's a bridge with water below, call tileloop_water on it.
	if ((_map5[tile] & 0xF8) == 0xC8) TileLoop_Water(tile);
}

static void ClickTile_TunnelBridge(TileIndex tile)
{
	/* not used */
}


static uint32 GetTileTrackStatus_TunnelBridge(TileIndex tile, TransportType mode)
{
	uint32 result;
	byte m5 = _map5[tile];

	if ((m5 & 0xF0) == 0) {
		/* This is a tunnel */
		if (((m5 & 0xCU) >> 2) == mode) {
			/* Tranport in the tunnel is compatible */
			return m5&1 ? 0x202 : 0x101;
		}
	} else if (m5 & 0x80) {
		/* This is a bridge */
		result = 0;
		if (((m5 & 0x6U) >> 1) == mode) {
			/* Transport over the bridge is compatible */
			result = m5&1 ? 0x202 : 0x101;
		}
		if (m5 & 0x40) {
			/* Bridge middle part */
			if (!(m5 & 0x20)) {
				/* Clear ground or water underneath */
				if ((m5 & 0x18) != 8)
					/* Clear ground */
					return result;
				else
					if (mode != TRANSPORT_WATER)
						return result;
			} else {
				/* Transport underneath */
				if ((m5 & 0x18U) >> 3 != mode)
					/* Incompatible transport underneath */
					return result;
			}
			/* If we've not returned yet, there is a compatible
			 * transport or water beneath, so we can add it to
			 * result */
			/* Why is this xor'd ? Can't it just be or'd? */
			result ^= m5&1 ? 0x101 : 0x202;
		}
		return result;
	} else {
		assert(0); /* This should never occur */
	}
	return 0;
}

static void ChangeTileOwner_TunnelBridge(TileIndex tile, byte old_player, byte new_player)
{
	if (!IsTileOwner(tile, old_player)) return;

	if (new_player != 255) {
		SetTileOwner(tile, new_player);
	}	else {
		if((_map5[tile] & 0xC0)==0xC0) {
			// the stuff BELOW the middle part is owned by the deleted player.
			if (!(_map5[tile] & (1 << 4 | 1 << 3))) {
				// convert railway into grass.
				_map5[tile] &= ~(1 << 5 | 1 << 4 | 1 << 3); // no transport route under bridge anymore..
			} else {
				// for road, change the owner of the road to local authority
				SetTileOwner(tile, OWNER_NONE);
			}
		} else {
			DoCommandByTile(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_TunnelBridge(Vehicle *v, TileIndex tile, int x, int y)
{
	int z;
	int dir, vdir;
	byte fc;

	if ((_map5[tile] & 0xF0) == 0) {
		z = GetSlopeZ(x, y) - v->z_pos;
		if (myabs(z) > 2)
			return 8;

		if (v->type == VEH_Train) {
			fc = (x&0xF)+(y<<4);

			dir = _map5[tile] & 3;
			vdir = v->direction >> 1;

			if (v->u.rail.track != 0x40 && dir == vdir) {
				if (v->subtype == TS_Front_Engine && fc == _tunnel_fractcoord_1[dir]) {
					if (v->spritenum < 4)
						SndPlayVehicleFx(SND_05_TRAIN_THROUGH_TUNNEL, v);
					return 0;
				}
				if (fc == _tunnel_fractcoord_2[dir]) {
					if (v->next == NULL)
						PBSClearTrack(v->tile, FIND_FIRST_BIT(v->u.rail.track));
					v->tile = tile;
					v->u.rail.track = 0x40;
					v->vehstatus |= VS_HIDDEN;
					return 4;
				}
			}

			if (dir == (vdir^2) && 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 = _map5[tile] & 3;
			vdir = v->direction >> 1;

			// 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 == (vdir^2) && (
				/* 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;
			}
		}
	} else if (_map5[tile] & 0x80) {
		if (v->type == VEH_Road || (v->type == VEH_Train && v->subtype == TS_Front_Engine)) {
			uint h;

			if (GetTileSlope(tile, &h) != 0)
				h += 8; // Compensate for possible foundation
			if (!(_map5[tile] & 0x40) || // start/end tile of bridge
					myabs(h - v->z_pos) > 2) { // high above the ground -> on the bridge
				/* modify speed of vehicle */
				uint16 spd = _bridge_speeds[_map2[tile] >> 4];
				if (v->type == VEH_Road) spd<<=1;
				if (spd < v->cur_speed)
					v->cur_speed = spd;
			}
		}
	}
	return 0;
}

TileIndex GetVehicleOutOfTunnelTile(const Vehicle *v)
{
	TileIndex tile;
	TileIndexDiff delta = (v->direction & 2) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	byte z = v->z_pos;

	for (tile = v->tile;; tile += delta) {
		if (IsTileType(tile, MP_TUNNELBRIDGE) && (_map5[tile] & 0xF0) == 0 &&
				GetTileZ(tile) == z)
			break;
	}
	return tile;
}

const TileTypeProcs _tile_type_tunnelbridge_procs = {
	DrawTile_TunnelBridge,					/* draw_tile_proc */
	GetSlopeZ_TunnelBridge,					/* get_slope_z_proc */
	ClearTile_TunnelBridge,					/* clear_tile_proc */
	GetAcceptedCargo_TunnelBridge,	/* get_accepted_cargo_proc */
	GetTileDesc_TunnelBridge,				/* get_tile_desc_proc */
	GetTileTrackStatus_TunnelBridge,/* get_tile_track_status_proc */
	ClickTile_TunnelBridge,					/* click_tile_proc */
	AnimateTile_TunnelBridge,				/* animate_tile_proc */
	TileLoop_TunnelBridge,					/* tile_loop_clear */
	ChangeTileOwner_TunnelBridge,		/* change_tile_owner_clear */
	NULL,														/* get_produced_cargo_proc */
	VehicleEnter_TunnelBridge,			/* vehicle_enter_tile_proc */
	NULL,														/* vehicle_leave_tile_proc */
	GetSlopeTileh_TunnelBridge,			/* get_slope_tileh_proc */
};