view src/road_cmd.cpp @ 9036:74210834ed21 draft

(svn r12855) -Codechange: do not use autoptr's for testing whether certain objects can be build, but check it directly in the pool so we do not have to call destructors in the testing phase. Stations still use the autoptr though.
author rubidium <rubidium@openttd.org>
date Wed, 23 Apr 2008 20:56:08 +0000 (2008-04-23)
parents 870efbdb988d
children 6e86ab2cba9f
line wrap: on
line source
/* $Id$ */

/** @file road_cmd.cpp */

#include "stdafx.h"
#include "openttd.h"
#include "bridge_map.h"
#include "bridge.h"
#include "cmd_helper.h"
#include "rail_map.h"
#include "road_map.h"
#include "road_internal.h"
#include "sprite.h"
#include "tile_cmd.h"
#include "landscape.h"
#include "town_map.h"
#include "viewport_func.h"
#include "command_func.h"
#include "town.h"
#include "yapf/yapf.h"
#include "depot_base.h"
#include "depot_func.h"
#include "newgrf.h"
#include "station_map.h"
#include "tunnel_map.h"
#include "variables.h"
#include "autoslope.h"
#include "transparency.h"
#include "tunnelbridge_map.h"
#include "window_func.h"
#include "strings_func.h"
#include "vehicle_func.h"
#include "vehicle_base.h"
#include "sound_func.h"
#include "road_func.h"
#include "tunnelbridge.h"
#include "cheat_func.h"
#include "functions.h"
#include "effectvehicle_func.h"

#include "table/sprites.h"
#include "table/strings.h"

#define M(x) (1 << (x))
/* Level crossings may only be built on these slopes */
static const uint32 VALID_LEVEL_CROSSING_SLOPES = (M(SLOPE_SEN) | M(SLOPE_ENW) | M(SLOPE_NWS) | M(SLOPE_NS) | M(SLOPE_WSE) | M(SLOPE_EW) | M(SLOPE_FLAT));
#undef M

/* Invalid RoadBits on slopes  */
static const RoadBits _invalid_tileh_slopes_road[2][15] = {
	/* The inverse of the mixable RoadBits on a leveled slope */
	{
		ROAD_NONE,         // SLOPE_FLAT
		ROAD_NE | ROAD_SE, // SLOPE_W
		ROAD_NE | ROAD_NW, // SLOPE_S

		ROAD_NE,           // SLOPE_SW
		ROAD_NW | ROAD_SW, // SLOPE_E
		ROAD_NONE,         // SLOPE_EW

		ROAD_NW,           // SLOPE_SE
		ROAD_NONE,         // SLOPE_WSE
		ROAD_SE | ROAD_SW, // SLOPE_N

		ROAD_SE,           // SLOPE_NW
		ROAD_NONE,         // SLOPE_NS
		ROAD_NONE,         // SLOPE_ENW

		ROAD_SW,           // SLOPE_NE
		ROAD_NONE,         // SLOPE_SEN
		ROAD_NONE          // SLOPE_NWS
	},
	/* The inverse of the allowed straight roads on a slope
	 * (with and without a foundation). */
	{
		ROAD_NONE, // SLOPE_FLAT
		ROAD_NONE, // SLOPE_W    Foundation
		ROAD_NONE, // SLOPE_S    Foundation

		ROAD_Y,    // SLOPE_SW
		ROAD_NONE, // SLOPE_E    Foundation
		ROAD_ALL,  // SLOPE_EW

		ROAD_X,    // SLOPE_SE
		ROAD_ALL,  // SLOPE_WSE
		ROAD_NONE, // SLOPE_N    Foundation

		ROAD_X,    // SLOPE_NW
		ROAD_ALL,  // SLOPE_NS
		ROAD_ALL,  // SLOPE_ENW

		ROAD_Y,    // SLOPE_NE
		ROAD_ALL,  // SLOPE_SEN
		ROAD_ALL   // SLOPE_NW
	}
};

Foundation GetRoadFoundation(Slope tileh, RoadBits bits);

bool CheckAllowRemoveRoad(TileIndex tile, RoadBits remove, Owner owner, bool *edge_road, RoadType rt)
{
	*edge_road = true;

	if (_game_mode == GM_EDITOR || remove == ROAD_NONE) return true;

	/* Water can always flood and towns can always remove "normal" road pieces.
	 * Towns are not be allowed to remove non "normal" road pieces, like tram
	 * tracks as that would result in trams that cannot turn. */
	if (_current_player == OWNER_WATER ||
			(rt == ROADTYPE_ROAD && !IsValidPlayer(_current_player))) return true;

	/* Only do the special processing if the road is owned
	 * by a town */
	if (owner != OWNER_TOWN) return (owner == OWNER_NONE) || CheckOwnership(owner);

	if (_cheats.magic_bulldozer.value) return true;

	/* Get a bitmask of which neighbouring roads has a tile */
	RoadBits n = ROAD_NONE;
	RoadBits present = GetAnyRoadBits(tile, rt);
	if (present & ROAD_NE && GetAnyRoadBits(TILE_ADDXY(tile, -1,  0), rt) & ROAD_SW) n |= ROAD_NE;
	if (present & ROAD_SE && GetAnyRoadBits(TILE_ADDXY(tile,  0,  1), rt) & ROAD_NW) n |= ROAD_SE;
	if (present & ROAD_SW && GetAnyRoadBits(TILE_ADDXY(tile,  1,  0), rt) & ROAD_NE) n |= ROAD_SW;
	if (present & ROAD_NW && GetAnyRoadBits(TILE_ADDXY(tile,  0, -1), rt) & ROAD_SE) n |= ROAD_NW;

	/* If 0 or 1 bits are set in n, or if no bits that match the bits to remove,
	 * then allow it */
	if (KillFirstBit(n) != ROAD_NONE && (n & remove) != ROAD_NONE) {
		*edge_road = false;
		/* you can remove all kind of roads with extra dynamite */
		if (_patches.extra_dynamite) return true;

		const Town *t = ClosestTownFromTile(tile, (uint)-1);

		SetDParam(0, t->index);
		_error_message = STR_2009_LOCAL_AUTHORITY_REFUSES;
		return false;
	}

	return true;
}

static bool CheckAllowRemoveRoad(TileIndex tile, RoadBits remove, bool *edge_road, RoadType rt)
{
	return CheckAllowRemoveRoad(tile, remove, GetRoadOwner(tile, rt), edge_road, rt);
}


/** Delete a piece of road.
 * @param tile tile where to remove road from
 * @param flags operation to perform
 * @param pieces roadbits to remove
 * @param rt roadtype to remove
 * @param crossing_check should we check if there is a tram track when we are removing road from crossing?
 */
static CommandCost RemoveRoad(TileIndex tile, uint32 flags, RoadBits pieces, RoadType rt, bool crossing_check, bool town_check = true)
{
	/* cost for removing inner/edge -roads */
	static const uint16 road_remove_cost[2] = {50, 18};

	/* true if the roadpiece was always removeable,
	 * false if it was a center piece. Affects town ratings drop */
	bool edge_road;

	Town *t = NULL;
	switch (GetTileType(tile)) {
		case MP_ROAD:
			if (_game_mode != GM_EDITOR && GetRoadOwner(tile, rt) == OWNER_TOWN) t = GetTownByTile(tile);
			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
			break;

		case MP_STATION:
			if (!IsDriveThroughStopTile(tile)) return CMD_ERROR;
			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
			break;

		case MP_TUNNELBRIDGE:
			if (GetTunnelBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
			if (GetVehicleTunnelBridge(tile, GetOtherTunnelBridgeEnd(tile)) != NULL) return CMD_ERROR;
			break;

		default:
			return CMD_ERROR;
	}

	RoadTypes rts = GetRoadTypes(tile);
	/* The tile doesn't have the given road type */
	if (!HasBit(rts, rt)) return CMD_ERROR;

	if (!CheckAllowRemoveRoad(tile, pieces, &edge_road, rt)) return CMD_ERROR;

	/* check if you're allowed to remove the street owned by a town
	 * removal allowance depends on difficulty setting */
	if (town_check && !CheckforTownRating(flags, t, ROAD_REMOVE)) return CMD_ERROR;

	if (!IsTileType(tile, MP_ROAD)) {
		/* If it's the last roadtype, just clear the whole tile */
		if (rts == RoadTypeToRoadTypes(rt)) return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);

		CommandCost cost(EXPENSES_CONSTRUCTION);
		if (IsTileType(tile, MP_TUNNELBRIDGE)) {
			TileIndex other_end = GetOtherTunnelBridgeEnd(tile);
			/* Pay for *every* tile of the bridge or tunnel */
			cost.AddCost((GetTunnelBridgeLength(other_end, tile) + 2) * _price.remove_road);
			if (flags & DC_EXEC) {
				SetRoadTypes(other_end, GetRoadTypes(other_end) & ~RoadTypeToRoadTypes(rt));
				SetRoadTypes(tile, GetRoadTypes(tile) & ~RoadTypeToRoadTypes(rt));

				/* Mark tiles diry that have been repaved */
				MarkTileDirtyByTile(tile);
				MarkTileDirtyByTile(other_end);
				if (IsBridge(tile)) {
					TileIndexDiff delta = TileOffsByDiagDir(GetTunnelBridgeDirection(tile));

					for (TileIndex t = tile + delta; t != other_end; t += delta) MarkTileDirtyByTile(t);
				}
			}
		} else {
			cost.AddCost(_price.remove_road);
			if (flags & DC_EXEC) {
				SetRoadTypes(tile, GetRoadTypes(tile) & ~RoadTypeToRoadTypes(rt));
				MarkTileDirtyByTile(tile);
			}
		}
		return cost;
	}

	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_NORMAL: {
			const Slope tileh = GetTileSlope(tile, NULL);
			RoadBits present = GetRoadBits(tile, rt);
			const RoadBits other = GetOtherRoadBits(tile, rt);
			const Foundation f = GetRoadFoundation(tileh, present);

			if (HasRoadWorks(tile)) return_cmd_error(STR_ROAD_WORKS_IN_PROGRESS);

			/* Autocomplete to a straight road
			 * @li on steep slopes
			 * @li if the bits of the other roadtypes result in another foundation
			 * @li if build on slopes is disabled */
			if (IsSteepSlope(tileh) || (IsStraightRoad(other) &&
					(other & _invalid_tileh_slopes_road[0][tileh & SLOPE_ELEVATED]) != ROAD_NONE) ||
					(tileh != SLOPE_FLAT && !_patches.build_on_slopes)) {
				pieces |= MirrorRoadBits(pieces);
			}

			/* limit the bits to delete to the existing bits. */
			pieces &= present;
			if (pieces == ROAD_NONE) return CMD_ERROR;

			/* Now set present what it will be after the remove */
			present ^= pieces;

			/* Check for invalid RoadBit combinations on slopes */
			if (tileh != SLOPE_FLAT && present != ROAD_NONE &&
					(present & _invalid_tileh_slopes_road[0][tileh & SLOPE_ELEVATED]) == present) {
				return CMD_ERROR;
			}

			if (town_check) ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
			if (flags & DC_EXEC) {
				if (present == ROAD_NONE) {
					RoadTypes rts = GetRoadTypes(tile) & ComplementRoadTypes(RoadTypeToRoadTypes(rt));
					if (rts == ROADTYPES_NONE) {
						/* Includes MarkTileDirtyByTile() */
						DoClearSquare(tile);
					} else {
						SetRoadBits(tile, ROAD_NONE, rt);
						SetRoadTypes(tile, rts);
						MarkTileDirtyByTile(tile);
					}
				} else {
					/* When bits are removed, you *always* end up with something that
					 * is not a complete straight road tile. However, trams do not have
					 * onewayness, so they cannot remove it either. */
					if (rt != ROADTYPE_TRAM) SetDisallowedRoadDirections(tile, DRD_NONE);
					SetRoadBits(tile, present, rt);
					MarkTileDirtyByTile(tile);
				}
			}

			/* If we change the foundation we have to pay for it. */
			return CommandCost(EXPENSES_CONSTRUCTION, CountBits(pieces) * _price.remove_road +
					((GetRoadFoundation(tileh, present) != f) ? _price.terraform : (Money)0));
		}

		case ROAD_TILE_CROSSING: {
			if (pieces & ComplementRoadBits(GetCrossingRoadBits(tile))) {
				return CMD_ERROR;
			}

			/* Don't allow road to be removed from the crossing when there is tram;
			 * we can't draw the crossing without trambits ;) */
			if (rt == ROADTYPE_ROAD && HasTileRoadType(tile, ROADTYPE_TRAM) && (flags & DC_EXEC || crossing_check)) return CMD_ERROR;

			if (rt == ROADTYPE_ROAD) {
				if (town_check) ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
			}

			if (flags & DC_EXEC) {
				RoadTypes rts = GetRoadTypes(tile) & ComplementRoadTypes(RoadTypeToRoadTypes(rt));
				if (rts == ROADTYPES_NONE) {
					MakeRailNormal(tile, GetTileOwner(tile), GetCrossingRailBits(tile), GetRailType(tile));
				} else {
					SetRoadTypes(tile, rts);
				}
				MarkTileDirtyByTile(tile);
				YapfNotifyTrackLayoutChange(tile, FindFirstTrack(GetTrackBits(tile)));
			}
			return CommandCost(EXPENSES_CONSTRUCTION, _price.remove_road * 2);
		}

		default:
		case ROAD_TILE_DEPOT:
			return CMD_ERROR;
	}
}


/** Delete a piece of road.
 * @param tile tile where to remove road from
 * @param flags operation to perform
 * @param p1 bit 0..3 road pieces to remove (RoadBits)
 *           bit 4..5 road type
 * @param p2 unused
 */
CommandCost CmdRemoveRoad(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	RoadType rt = (RoadType)GB(p1, 4, 2);
	if (!IsValidRoadType(rt)) return CMD_ERROR;

	RoadBits pieces = Extract<RoadBits, 0>(p1);

	return RemoveRoad(tile, flags, pieces, rt, true);
}

/**
 * Calculate the costs for roads on slopes
 *  Aside modify the RoadBits to fit on the slopes
 *
 * @note The RoadBits are modified too!
 * @param tileh The current slope
 * @param pieces The RoadBits we want to add
 * @param existing The existent RoadBits of the current type
 * @param other The other existent RoadBits
 * @return The costs for these RoadBits on this slope
 */
static CommandCost CheckRoadSlope(Slope tileh, RoadBits *pieces, RoadBits existing, RoadBits other)
{
	/* Remove already build pieces */
	CLRBITS(*pieces, existing);

	/* If we can't build anything stop here */
	if (*pieces == ROAD_NONE) return CMD_ERROR;

	/* All RoadBit combos are valid on flat land */
	if (tileh == SLOPE_FLAT) return CommandCost();

	/* Proceed steep Slopes first to reduce lookup table size */
	if (IsSteepSlope(tileh)) {
		/* Force straight roads. */
		*pieces |= MirrorRoadBits(*pieces);

		/* Use existing as all existing since only straight
		 * roads are allowed here. */
		existing |= other;

		if ((existing == ROAD_NONE || existing == *pieces) && IsStraightRoad(*pieces)) {
			return CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);
		}
		return CMD_ERROR;
	}

	/* Save the merge of all bits of the current type */
	RoadBits type_bits = existing | *pieces;

	/* Roads on slopes */
	if (_patches.build_on_slopes && (_invalid_tileh_slopes_road[0][tileh] & (other | type_bits)) == ROAD_NONE) {

		/* If we add leveling we've got to pay for it */
		if ((other | existing) == ROAD_NONE) return CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);

		return CommandCost();
	}

	/* Autocomplete uphill roads */
	*pieces |= MirrorRoadBits(*pieces);
	type_bits = existing | *pieces;

	/* Uphill roads */
	if (IsStraightRoad(type_bits) && (other == type_bits || other == ROAD_NONE) &&
			(_invalid_tileh_slopes_road[1][tileh] & (other | type_bits)) == ROAD_NONE) {

		/* Slopes with foundation ? */
		if (IsSlopeWithOneCornerRaised(tileh)) {

			/* Prevent build on slopes if it isn't allowed */
			if (_patches.build_on_slopes) {

				/* If we add foundation we've got to pay for it */
				if ((other | existing) == ROAD_NONE) return CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);

				return CommandCost();
			}
		} else {
			if (CountBits(existing) == 1) return CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);
			return CommandCost();
		}
	}
	return CMD_ERROR;
}

/** Build a piece of road.
 * @param tile tile where to build road
 * @param flags operation to perform
 * @param p1 bit 0..3 road pieces to build (RoadBits)
 *           bit 4..5 road type
 *           bit 6..7 disallowed directions to toggle
 * @param p2 the town that is building the road (0 if not applicable)
 */
CommandCost CmdBuildRoad(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	CommandCost cost(EXPENSES_CONSTRUCTION);

	RoadBits existing = ROAD_NONE;
	RoadBits other_bits = ROAD_NONE;

	/* Road pieces are max 4 bitset values (NE, NW, SE, SW) and town can only be non-zero
	 * if a non-player is building the road */
	if ((IsValidPlayer(_current_player) && p2 != 0) || (_current_player == OWNER_TOWN && !IsValidTownID(p2))) return CMD_ERROR;

	RoadBits pieces = Extract<RoadBits, 0>(p1);

	/* do not allow building 'zero' road bits, code wouldn't handle it */
	if (pieces == ROAD_NONE) return CMD_ERROR;

	RoadType rt = (RoadType)GB(p1, 4, 2);
	if (!IsValidRoadType(rt) || !ValParamRoadType(rt)) return CMD_ERROR;

	DisallowedRoadDirections toggle_drd = (DisallowedRoadDirections)GB(p1, 6, 2);

	Slope tileh = GetTileSlope(tile, NULL);

	switch (GetTileType(tile)) {
		case MP_ROAD:
			switch (GetRoadTileType(tile)) {
				case ROAD_TILE_NORMAL: {
					if (HasRoadWorks(tile)) return_cmd_error(STR_ROAD_WORKS_IN_PROGRESS);

					other_bits = GetOtherRoadBits(tile, rt);
					if (!HasTileRoadType(tile, rt)) break;

					existing = GetRoadBits(tile, rt);
					bool crossing = !IsStraightRoad(existing | pieces);
					if (rt != ROADTYPE_TRAM && (GetDisallowedRoadDirections(tile) != DRD_NONE || toggle_drd != DRD_NONE) && crossing) {
						/* Junctions cannot be one-way */
						return_cmd_error(STR_ERR_ONEWAY_ROADS_CAN_T_HAVE_JUNCTION);
					}
					if ((existing & pieces) == pieces) {
						/* We only want to set the (dis)allowed road directions */
						if (toggle_drd != DRD_NONE && rt != ROADTYPE_TRAM && GetRoadOwner(tile, ROADTYPE_ROAD) == _current_player) {
							if (crossing) return_cmd_error(STR_ERR_ONEWAY_ROADS_CAN_T_HAVE_JUNCTION);

							if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;

							/* Ignore half built tiles */
							if (flags & DC_EXEC && rt != ROADTYPE_TRAM && IsStraightRoad(existing)) {
								SetDisallowedRoadDirections(tile, GetDisallowedRoadDirections(tile) ^ toggle_drd);
								MarkTileDirtyByTile(tile);
							}
							return CommandCost();
						}
						return_cmd_error(STR_1007_ALREADY_BUILT);
					}
				} break;

				case ROAD_TILE_CROSSING:
					if (HasTileRoadType(tile, rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
					other_bits = GetCrossingRoadBits(tile);
					if (pieces & ComplementRoadBits(other_bits)) goto do_clear;
					break;

				default:
				case ROAD_TILE_DEPOT:
					goto do_clear;
			}
			break;

		case MP_RAILWAY: {
			if (IsSteepSlope(tileh)) {
				return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
			}

			/* Level crossings may only be built on these slopes */
			if (!HasBit(VALID_LEVEL_CROSSING_SLOPES, tileh)) {
				return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
			}

			if (GetRailTileType(tile) != RAIL_TILE_NORMAL) goto do_clear;

			Axis roaddir;
			switch (GetTrackBits(tile)) {
				case TRACK_BIT_X:
					if (pieces & ROAD_X) goto do_clear;
					roaddir = AXIS_Y;
					break;

				case TRACK_BIT_Y:
					if (pieces & ROAD_Y) goto do_clear;
					roaddir = AXIS_X;
					break;

				default: goto do_clear;
			}

			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;

			if (flags & DC_EXEC) {
				YapfNotifyTrackLayoutChange(tile, FindFirstTrack(GetTrackBits(tile)));
				/* Always add road to the roadtypes (can't draw without it) */
				MakeRoadCrossing(tile, _current_player, _current_player, _current_player, GetTileOwner(tile), roaddir, GetRailType(tile), RoadTypeToRoadTypes(rt) | ROADTYPES_ROAD, p2);
				UpdateLevelCrossing(tile, false);
				MarkTileDirtyByTile(tile);
			}
			return CommandCost(EXPENSES_CONSTRUCTION, _price.build_road * (rt == ROADTYPE_ROAD ? 2 : 4));
		}

		case MP_STATION:
			if (!IsDriveThroughStopTile(tile)) return CMD_ERROR;
			if (HasTileRoadType(tile, rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
			break;

		case MP_TUNNELBRIDGE:
			if (GetTunnelBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
			if (HasTileRoadType(tile, rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
			/* Don't allow adding roadtype to the bridge/tunnel when vehicles are already driving on it */
			if (GetVehicleTunnelBridge(tile, GetOtherTunnelBridgeEnd(tile)) != NULL) return CMD_ERROR;
			break;

		default: {
do_clear:;
			CommandCost ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
			if (CmdFailed(ret)) return ret;
			cost.AddCost(ret);
		} break;
	}

	if (other_bits != pieces) {
		/* Check the foundation/slopes when adding road/tram bits */
		CommandCost ret = CheckRoadSlope(tileh, &pieces, existing, other_bits);
		/* Return an error if we need to build a foundation (ret != 0) but the
		 * current patch-setting is turned off (or stupid AI@work) */
		if (CmdFailed(ret) || (ret.GetCost() != 0 && !_patches.build_on_slopes)) {
			return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
		}
		cost.AddCost(ret);
	}

	if (IsTileType(tile, MP_ROAD)) {
		/* Don't put the pieces that already exist */
		pieces &= ComplementRoadBits(existing);

		/* Check if new road bits will have the same foundation as other existing road types */
		if (IsNormalRoad(tile)) {
			Slope slope = GetTileSlope(tile, NULL);
			Foundation found_new = GetRoadFoundation(slope, pieces | existing);

			/* Test if all other roadtypes can be built at that foundation */
			for (RoadType rtest = ROADTYPE_ROAD; rtest < ROADTYPE_END; rtest++) {
				if (rtest != rt) { // check only other road types
					RoadBits bits = GetRoadBits(tile, rtest);
					/* do not check if there are not road bits of given type */
					if (bits != ROAD_NONE && GetRoadFoundation(slope, bits) != found_new) {
						return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
					}
				}
			}
		}
	}

	if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;

	cost.AddCost(CountBits(pieces) * _price.build_road);
	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
		/* Pay for *every* tile of the bridge or tunnel */
		cost.MultiplyCost(GetTunnelBridgeLength(GetOtherTunnelBridgeEnd(tile), tile) + 2);
	}

	if (flags & DC_EXEC) {
		switch (GetTileType(tile)) {
			case MP_ROAD: {
				RoadTileType rtt = GetRoadTileType(tile);
				if (existing == ROAD_NONE || rtt == ROAD_TILE_CROSSING) {
					SetRoadTypes(tile, GetRoadTypes(tile) | RoadTypeToRoadTypes(rt));
					SetRoadOwner(tile, rt, _current_player);
					if (_current_player == OWNER_TOWN && rt == ROADTYPE_ROAD) SetTownIndex(tile, p2);
				}
				if (rtt != ROAD_TILE_CROSSING) SetRoadBits(tile, existing | pieces, rt);
			} break;

			case MP_TUNNELBRIDGE: {
				TileIndex other_end = GetOtherTunnelBridgeEnd(tile);

				SetRoadTypes(other_end, GetRoadTypes(other_end) | RoadTypeToRoadTypes(rt));
				SetRoadTypes(tile, GetRoadTypes(tile) | RoadTypeToRoadTypes(rt));

				/* Mark tiles diry that have been repaved */
				MarkTileDirtyByTile(other_end);
				MarkTileDirtyByTile(tile);
				if (IsBridge(tile)) {
					TileIndexDiff delta = TileOffsByDiagDir(GetTunnelBridgeDirection(tile));

					for (TileIndex t = tile + delta; t != other_end; t += delta) MarkTileDirtyByTile(t);
				}
			} break;

			case MP_STATION:
				SetRoadTypes(tile, GetRoadTypes(tile) | RoadTypeToRoadTypes(rt));
				break;

			default:
				MakeRoadNormal(tile, pieces, RoadTypeToRoadTypes(rt), p2, _current_player, _current_player, _current_player);
				break;
		}

		if (rt != ROADTYPE_TRAM && IsNormalRoadTile(tile)) {
			existing |= pieces;
			SetDisallowedRoadDirections(tile, IsStraightRoad(existing) ?
					GetDisallowedRoadDirections(tile) ^ toggle_drd : DRD_NONE);
		}

		MarkTileDirtyByTile(tile);
	}
	return cost;
}

/** Build a long piece of road.
 * @param end_tile end tile of drag
 * @param flags operation to perform
 * @param p1 start tile of drag
 * @param p2 various bitstuffed elements
 * - p2 = (bit 0) - start tile starts in the 2nd half of tile (p2 & 1)
 * - p2 = (bit 1) - end tile starts in the 2nd half of tile (p2 & 2)
 * - p2 = (bit 2) - direction: 0 = along x-axis, 1 = along y-axis (p2 & 4)
 * - p2 = (bit 3 + 4) - road type
 * - p2 = (bit 5) - set road direction
 */
CommandCost CmdBuildLongRoad(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
{
	CommandCost cost(EXPENSES_CONSTRUCTION);
	bool had_bridge = false;
	bool had_tunnel = false;
	bool had_success = false;
	DisallowedRoadDirections drd = DRD_NORTHBOUND;

	_error_message = INVALID_STRING_ID;

	if (p1 >= MapSize()) return CMD_ERROR;

	TileIndex start_tile = p1;
	RoadType rt = (RoadType)GB(p2, 3, 2);
	if (!IsValidRoadType(rt) || !ValParamRoadType(rt)) return CMD_ERROR;

	/* Only drag in X or Y direction dictated by the direction variable */
	if (!HasBit(p2, 2) && TileY(start_tile) != TileY(end_tile)) return CMD_ERROR; // x-axis
	if (HasBit(p2, 2)  && TileX(start_tile) != TileX(end_tile)) return CMD_ERROR; // y-axis

	/* Swap start and ending tile, also the half-tile drag var (bit 0 and 1) */
	if (start_tile > end_tile || (start_tile == end_tile && HasBit(p2, 0))) {
		TileIndex t = start_tile;
		start_tile = end_tile;
		end_tile = t;
		p2 ^= IsInsideMM(p2 & 3, 1, 3) ? 3 : 0;
		drd = DRD_SOUTHBOUND;
	}

	/* On the X-axis, we have to swap the initial bits, so they
	 * will be interpreted correctly in the GTTS. Futhermore
	 * when you just 'click' on one tile to build them. */
	if (HasBit(p2, 2) == (start_tile == end_tile && HasBit(p2, 0) == HasBit(p2, 1))) drd ^= DRD_BOTH;
	/* No disallowed direction bits have to be toggled */
	if (!HasBit(p2, 5)) drd = DRD_NONE;

	TileIndex tile = start_tile;
	/* Start tile is the small number. */
	for (;;) {
		RoadBits bits = HasBit(p2, 2) ? ROAD_Y : ROAD_X;

		if (tile == end_tile && !HasBit(p2, 1)) bits &= ROAD_NW | ROAD_NE;
		if (tile == start_tile && HasBit(p2, 0)) bits &= ROAD_SE | ROAD_SW;

		CommandCost ret = DoCommand(tile, drd << 6 | rt << 4 | bits, 0, flags, CMD_BUILD_ROAD);
		if (CmdFailed(ret)) {
			if (_error_message != STR_1007_ALREADY_BUILT) return CMD_ERROR;
		} else {
			had_success = true;
			/* Only pay for the upgrade on one side of the bridges and tunnels */
			if (IsTileType(tile, MP_TUNNELBRIDGE)) {
				if (IsBridge(tile)) {
					if ((!had_bridge || GetTunnelBridgeDirection(tile) == DIAGDIR_SE || GetTunnelBridgeDirection(tile) == DIAGDIR_SW)) {
						cost.AddCost(ret);
					}
					had_bridge = true;
				} else { // IsTunnel(tile)
					if ((!had_tunnel || GetTunnelBridgeDirection(tile) == DIAGDIR_SE || GetTunnelBridgeDirection(tile) == DIAGDIR_SW)) {
						cost.AddCost(ret);
					}
					had_tunnel = true;
				}
			} else {
				cost.AddCost(ret);
			}
		}

		if (tile == end_tile) break;

		tile += HasBit(p2, 2) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	}

	return !had_success ? CMD_ERROR : cost;
}

/** Remove a long piece of road.
 * @param end_tile end tile of drag
 * @param flags operation to perform
 * @param p1 start tile of drag
 * @param p2 various bitstuffed elements
 * - p2 = (bit 0) - start tile starts in the 2nd half of tile (p2 & 1)
 * - p2 = (bit 1) - end tile starts in the 2nd half of tile (p2 & 2)
 * - p2 = (bit 2) - direction: 0 = along x-axis, 1 = along y-axis (p2 & 4)
 * - p2 = (bit 3 + 4) - road type
 */
CommandCost CmdRemoveLongRoad(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
{
	CommandCost cost(EXPENSES_CONSTRUCTION);

	if (p1 >= MapSize()) return CMD_ERROR;

	TileIndex start_tile = p1;
	RoadType rt = (RoadType)GB(p2, 3, 2);
	if (!IsValidRoadType(rt)) return CMD_ERROR;

	/* Only drag in X or Y direction dictated by the direction variable */
	if (!HasBit(p2, 2) && TileY(start_tile) != TileY(end_tile)) return CMD_ERROR; // x-axis
	if (HasBit(p2, 2)  && TileX(start_tile) != TileX(end_tile)) return CMD_ERROR; // y-axis

	/* Swap start and ending tile, also the half-tile drag var (bit 0 and 1) */
	if (start_tile > end_tile || (start_tile == end_tile && HasBit(p2, 0))) {
		TileIndex t = start_tile;
		start_tile = end_tile;
		end_tile = t;
		p2 ^= IsInsideMM(p2 & 3, 1, 3) ? 3 : 0;
	}

	Money money = GetAvailableMoneyForCommand();
	TileIndex tile = start_tile;
	/* Start tile is the small number. */
	for (;;) {
		RoadBits bits = HasBit(p2, 2) ? ROAD_Y : ROAD_X;

		if (tile == end_tile && !HasBit(p2, 1)) bits &= ROAD_NW | ROAD_NE;
		if (tile == start_tile && HasBit(p2, 0)) bits &= ROAD_SE | ROAD_SW;

		/* try to remove the halves. */
		if (bits != 0) {
			CommandCost ret = RemoveRoad(tile, flags & ~DC_EXEC, bits, rt, true);
			if (CmdSucceeded(ret)) {
				if (flags & DC_EXEC) {
					money -= ret.GetCost();
					if (money < 0) {
						_additional_cash_required = DoCommand(end_tile, start_tile, p2, flags & ~DC_EXEC, CMD_REMOVE_LONG_ROAD).GetCost();
						return cost;
					}
					RemoveRoad(tile, flags, bits, rt, true, false);
				}
				cost.AddCost(ret);
			}
		}

		if (tile == end_tile) break;

		tile += HasBit(p2, 2) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	}

	return (cost.GetCost() == 0) ? CMD_ERROR : cost;
}

/** Build a road depot.
 * @param tile tile where to build the depot
 * @param flags operation to perform
 * @param p1 bit 0..1 entrance direction (DiagDirection)
 *           bit 2..3 road type
 * @param p2 unused
 *
 * @todo When checking for the tile slope,
 * distingush between "Flat land required" and "land sloped in wrong direction"
 */
CommandCost CmdBuildRoadDepot(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	DiagDirection dir = Extract<DiagDirection, 0>(p1);
	RoadType rt = (RoadType)GB(p1, 2, 2);

	if (!IsValidRoadType(rt) || !ValParamRoadType(rt)) return CMD_ERROR;

	Slope tileh = GetTileSlope(tile, NULL);
	if (tileh != SLOPE_FLAT && (
				!_patches.build_on_slopes ||
				IsSteepSlope(tileh) ||
				!CanBuildDepotByTileh(dir, tileh)
			)) {
		return_cmd_error(STR_0007_FLAT_LAND_REQUIRED);
	}

	CommandCost cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
	if (CmdFailed(cost)) return CMD_ERROR;

	if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);

	if (!Depot::CanAllocateItem()) return CMD_ERROR;

	if (flags & DC_EXEC) {
		Depot *dep = new Depot(tile);
		dep->town_index = ClosestTownFromTile(tile, (uint)-1)->index;

		MakeRoadDepot(tile, _current_player, dir, rt);
		MarkTileDirtyByTile(tile);
	}
	return cost.AddCost(_price.build_road_depot);
}

static CommandCost RemoveRoadDepot(TileIndex tile, uint32 flags)
{
	if (!CheckTileOwnership(tile) && _current_player != OWNER_WATER) return CMD_ERROR;

	if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;

	if (flags & DC_EXEC) {
		DoClearSquare(tile);
		delete GetDepotByTile(tile);
	}

	return CommandCost(EXPENSES_CONSTRUCTION, _price.remove_road_depot);
}

static CommandCost ClearTile_Road(TileIndex tile, byte flags)
{
	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_NORMAL: {
			RoadBits b = GetAllRoadBits(tile);

			/* Clear the road if only one piece is on the tile OR the AI tries
			 * to clear town road OR we are not using the DC_AUTO flag */
			if ((CountBits(b) == 1 && GetRoadBits(tile, ROADTYPE_TRAM) == ROAD_NONE) ||
			    ((flags & DC_AI_BUILDING) && IsTileOwner(tile, OWNER_TOWN)) ||
			    !(flags & DC_AUTO)
				) {
				RoadTypes rts = GetRoadTypes(tile);
				CommandCost ret(EXPENSES_CONSTRUCTION);
				for (RoadType rt = ROADTYPE_ROAD; rt < ROADTYPE_END; rt++) {
					if (HasBit(rts, rt)) {
						CommandCost tmp_ret = RemoveRoad(tile, flags, GetRoadBits(tile, rt), rt, true);
						if (CmdFailed(tmp_ret)) return tmp_ret;
						ret.AddCost(tmp_ret);
					}
				}
				return ret;
			}
			return_cmd_error(STR_1801_MUST_REMOVE_ROAD_FIRST);
		}

		case ROAD_TILE_CROSSING: {
			RoadTypes rts = GetRoadTypes(tile);
			CommandCost ret(EXPENSES_CONSTRUCTION);

			if (flags & DC_AUTO) return_cmd_error(STR_1801_MUST_REMOVE_ROAD_FIRST);

			/* Must iterate over the roadtypes in a reverse manner because
			 * tram tracks must be removed before the road bits. */
			RoadType rt = ROADTYPE_HWAY;
			do {
				if (HasBit(rts, rt)) {
					CommandCost tmp_ret = RemoveRoad(tile, flags, GetCrossingRoadBits(tile), rt, false);
					if (CmdFailed(tmp_ret)) return tmp_ret;
					ret.AddCost(tmp_ret);
				}
			} while (rt-- != ROADTYPE_ROAD);

			if (flags & DC_EXEC) {
				DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
			}
			return ret;
		}

		default:
		case ROAD_TILE_DEPOT:
			if (flags & DC_AUTO) {
				return_cmd_error(STR_2004_BUILDING_MUST_BE_DEMOLISHED);
			}
			return RemoveRoadDepot(tile, flags);
	}
}


struct DrawRoadTileStruct {
	uint16 image;
	byte subcoord_x;
	byte subcoord_y;
};

#include "table/road_land.h"

/**
 * Get the foundationtype of a RoadBits Slope combination
 *
 * @param tileh The Slope part
 * @param bits The RoadBits part
 * @return The resulting Foundation
 */
Foundation GetRoadFoundation(Slope tileh, RoadBits bits)
{
	/* Flat land and land without a road doesn't require a foundation */
	if (tileh == SLOPE_FLAT || bits == ROAD_NONE) return FOUNDATION_NONE;

	if (!IsSteepSlope(tileh)) {
		/* Leveled RoadBits on a slope */
		if ((_invalid_tileh_slopes_road[0][tileh] & bits) == ROAD_NONE) return FOUNDATION_LEVELED;

		/* Straight roads without foundation on a slope */
		if (!IsSlopeWithOneCornerRaised(tileh) &&
				(_invalid_tileh_slopes_road[1][tileh] & bits) == ROAD_NONE)
			return FOUNDATION_NONE;
	}

	/* Roads on steep Slopes or on Slopes with one corner raised */
	return (bits == ROAD_X ? FOUNDATION_INCLINED_X : FOUNDATION_INCLINED_Y);
}

const byte _road_sloped_sprites[14] = {
	0,  0,  2,  0,
	0,  1,  0,  0,
	3,  0,  0,  0,
	0,  0
};

/**
 * Whether to draw unpaved roads regardless of the town zone.
 * By default, OpenTTD always draws roads as unpaved if they are on a desert
 * tile or above the snowline. Newgrf files, however, can set a bit that allows
 * paved roads to be built on desert tiles as they would be on grassy tiles.
 *
 * @param tile The tile the road is on
 * @param roadside What sort of road this is
 * @return True if the road should be drawn unpaved regardless of the roadside.
 */
static bool AlwaysDrawUnpavedRoads(TileIndex tile, Roadside roadside)
{
	return (IsOnSnow(tile) &&
			!(_opt.landscape == LT_TROPIC && HasGrfMiscBit(GMB_DESERT_PAVED_ROADS) &&
				roadside != ROADSIDE_BARREN && roadside != ROADSIDE_GRASS && roadside != ROADSIDE_GRASS_ROAD_WORKS));
}

/**
 * Draws the catenary for the given tile
 * @param ti   information about the tile (slopes, height etc)
 * @param tram the roadbits for the tram
 */
void DrawTramCatenary(const TileInfo *ti, RoadBits tram)
{
	/* Do not draw catenary if it is invisible */
	if (IsInvisibilitySet(TO_CATENARY)) return;

	/* Don't draw the catenary under a low bridge */
	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !IsTransparencySet(TO_CATENARY)) {
		uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));

		if (height <= GetTileMaxZ(ti->tile) + TILE_HEIGHT) return;
	}

	SpriteID front;
	SpriteID back;

	if (ti->tileh != SLOPE_FLAT) {
		back  = SPR_TRAMWAY_BACK_WIRES_SLOPED  + _road_sloped_sprites[ti->tileh - 1];
		front = SPR_TRAMWAY_FRONT_WIRES_SLOPED + _road_sloped_sprites[ti->tileh - 1];
	} else {
		back  = SPR_TRAMWAY_BASE + _road_backpole_sprites_1[tram];
		front = SPR_TRAMWAY_BASE + _road_frontwire_sprites_1[tram];
	}

	AddSortableSpriteToDraw(back,  PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, IsTransparencySet(TO_CATENARY));
	AddSortableSpriteToDraw(front, PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, IsTransparencySet(TO_CATENARY));
}

/**
 * Draws details on/around the road
 * @param img the sprite to draw
 * @param ti  the tile to draw on
 * @param dx  the offset from the top of the BB of the tile
 * @param dy  the offset from the top of the BB of the tile
 * @param h   the height of the sprite to draw
 */
static void DrawRoadDetail(SpriteID img, const TileInfo *ti, int dx, int dy, int h)
{
	int x = ti->x | dx;
	int y = ti->y | dy;
	byte z = ti->z;
	if (ti->tileh != SLOPE_FLAT) z = GetSlopeZ(x, y);
	AddSortableSpriteToDraw(img, PAL_NONE, x, y, 2, 2, h, z);
}

/**
 * Draw ground sprite and road pieces
 * @param ti TileInfo
 */
static void DrawRoadBits(TileInfo *ti)
{
	RoadBits road = GetRoadBits(ti->tile, ROADTYPE_ROAD);
	RoadBits tram = GetRoadBits(ti->tile, ROADTYPE_TRAM);

	SpriteID image = 0;
	SpriteID pal = PAL_NONE;

	if (ti->tileh != SLOPE_FLAT) {
		DrawFoundation(ti, GetRoadFoundation(ti->tileh, road | tram));

		/* DrawFoundation() modifies ti.
		 * Default sloped sprites.. */
		if (ti->tileh != SLOPE_FLAT) image = _road_sloped_sprites[ti->tileh - 1] + 0x53F;
	}

	if (image == 0) image = _road_tile_sprites_1[road != ROAD_NONE ? road : tram];

	Roadside roadside = GetRoadside(ti->tile);

	if (AlwaysDrawUnpavedRoads(ti->tile, roadside)) {
		image += 19;
	} else {
		switch (roadside) {
			case ROADSIDE_BARREN:           pal = PALETTE_TO_BARE_LAND; break;
			case ROADSIDE_GRASS:            break;
			case ROADSIDE_GRASS_ROAD_WORKS: break;
			default:                        image -= 19; break; // Paved
		}
	}

	DrawGroundSprite(image, pal);

	/* For tram we overlay the road graphics with either tram tracks only
	 * (when there is actual road beneath the trams) or with tram tracks
	 * and some dirts which hides the road graphics */
	if (tram != ROAD_NONE) {
		if (ti->tileh != SLOPE_FLAT) {
			image = _road_sloped_sprites[ti->tileh - 1] + SPR_TRAMWAY_SLOPED_OFFSET;
		} else {
			image = _road_tile_sprites_1[tram] - SPR_ROAD_Y;
		}
		image += (road == ROAD_NONE) ? SPR_TRAMWAY_TRAM : SPR_TRAMWAY_OVERLAY;
		DrawGroundSprite(image, pal);
	}

	if (road != ROAD_NONE) {
		DisallowedRoadDirections drd = GetDisallowedRoadDirections(ti->tile);
		if (drd != DRD_NONE) {
			DrawRoadDetail(SPR_ONEWAY_BASE + drd - 1 + ((road == ROAD_X) ? 0 : 3), ti, 8, 8, 0);
		}
	}

	if (HasRoadWorks(ti->tile)) {
		/* Road works */
		DrawGroundSprite((road | tram) & ROAD_X ? SPR_EXCAVATION_X : SPR_EXCAVATION_Y, PAL_NONE);
		return;
	}

	if (tram != ROAD_NONE) DrawTramCatenary(ti, tram);

	/* Return if full detail is disabled, or we are zoomed fully out. */
	if (!HasBit(_display_opt, DO_FULL_DETAIL) || _cur_dpi->zoom > ZOOM_LVL_DETAIL) return;

	/* Do not draw details (street lights, trees) under low bridge */
	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && (roadside == ROADSIDE_TREES || roadside == ROADSIDE_STREET_LIGHTS)) {
		uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));
		uint minz = GetTileMaxZ(ti->tile) + 2 * TILE_HEIGHT;

		if (roadside == ROADSIDE_TREES) minz += TILE_HEIGHT;

		if (height < minz) return;
	}

	/* If there are no road bits, return, as there is nothing left to do */
	if (CountBits(road) < 2) return;

	/* Draw extra details. */
	for (const DrawRoadTileStruct *drts = _road_display_table[roadside][road | tram]; drts->image != 0; drts++) {
		DrawRoadDetail(drts->image, ti, drts->subcoord_x, drts->subcoord_y, 0x10);
	}
}

static void DrawTile_Road(TileInfo *ti)
{
	switch (GetRoadTileType(ti->tile)) {
		case ROAD_TILE_NORMAL:
			DrawRoadBits(ti);
			break;

		case ROAD_TILE_CROSSING: {
			if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);

			SpriteID image = GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.crossing;
			SpriteID pal = PAL_NONE;

			if (GetCrossingRoadAxis(ti->tile) == AXIS_X) image++;
			if (IsCrossingBarred(ti->tile)) image += 2;

			Roadside roadside = GetRoadside(ti->tile);

			if (AlwaysDrawUnpavedRoads(ti->tile, roadside)) {
				image += 8;
			} else {
				switch (roadside) {
					case ROADSIDE_BARREN: pal = PALETTE_TO_BARE_LAND; break;
					case ROADSIDE_GRASS:  break;
					default:              image += 4; break; // Paved
				}
			}

			DrawGroundSprite(image, pal);
			if (HasTileRoadType(ti->tile, ROADTYPE_TRAM)) {
				DrawGroundSprite(SPR_TRAMWAY_OVERLAY + (GetCrossingRoadAxis(ti->tile) ^ 1), pal);
				DrawTramCatenary(ti, GetCrossingRoadBits(ti->tile));
			}
			if (HasCatenary(GetRailType(ti->tile))) DrawCatenary(ti);
			break;
		}

		default:
		case ROAD_TILE_DEPOT: {
			if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);

			SpriteID palette = PLAYER_SPRITE_COLOR(GetTileOwner(ti->tile));

			const DrawTileSprites *dts;
			if (HasTileRoadType(ti->tile, ROADTYPE_TRAM)) {
				dts =  &_tram_depot[GetRoadDepotDirection(ti->tile)];
			} else {
				dts =  &_road_depot[GetRoadDepotDirection(ti->tile)];
			}

			DrawGroundSprite(dts->ground.sprite, PAL_NONE);

			/* End now if buildings are invisible */
			if (IsInvisibilitySet(TO_BUILDINGS)) break;

			for (const DrawTileSeqStruct *dtss = dts->seq; dtss->image.sprite != 0; dtss++) {
				SpriteID image = dtss->image.sprite;
				SpriteID pal;

				if (!IsTransparencySet(TO_BUILDINGS) && HasBit(image, PALETTE_MODIFIER_COLOR)) {
					pal = palette;
				} else {
					pal = PAL_NONE;
				}

				AddSortableSpriteToDraw(
					image, pal,
					ti->x + dtss->delta_x, ti->y + dtss->delta_y,
					dtss->size_x, dtss->size_y,
					dtss->size_z, ti->z,
					IsTransparencySet(TO_BUILDINGS)
				);
			}
			break;
		}
	}
	DrawBridgeMiddle(ti);
}

void DrawRoadDepotSprite(int x, int y, DiagDirection dir, RoadType rt)
{
	SpriteID palette = PLAYER_SPRITE_COLOR(_local_player);
	const DrawTileSprites *dts = (rt == ROADTYPE_TRAM) ? &_tram_depot[dir] : &_road_depot[dir];

	x += 33;
	y += 17;

	DrawSprite(dts->ground.sprite, PAL_NONE, x, y);

	for (const DrawTileSeqStruct *dtss = dts->seq; dtss->image.sprite != 0; dtss++) {
		Point pt = RemapCoords(dtss->delta_x, dtss->delta_y, dtss->delta_z);
		SpriteID image = dtss->image.sprite;

		DrawSprite(image, HasBit(image, PALETTE_MODIFIER_COLOR) ? palette : PAL_NONE, x + pt.x, y + pt.y);
	}
}

static uint GetSlopeZ_Road(TileIndex tile, uint x, uint y)
{
	uint z;
	Slope tileh = GetTileSlope(tile, &z);

	if (tileh == SLOPE_FLAT) return z;
	if (IsNormalRoad(tile)) {
		Foundation f = GetRoadFoundation(tileh, GetAllRoadBits(tile));
		z += ApplyFoundationToSlope(f, &tileh);
		return z + GetPartialZ(x & 0xF, y & 0xF, tileh);
	} else {
		return z + TILE_HEIGHT;
	}
}

static Foundation GetFoundation_Road(TileIndex tile, Slope tileh)
{
	if (IsNormalRoad(tile)) {
		return GetRoadFoundation(tileh, GetAllRoadBits(tile));
	} else {
		return FlatteningFoundation(tileh);
	}
}

static void GetAcceptedCargo_Road(TileIndex tile, AcceptedCargo ac)
{
	/* not used */
}

static void AnimateTile_Road(TileIndex tile)
{
	if (IsLevelCrossing(tile)) MarkTileDirtyByTile(tile);
}


static const Roadside _town_road_types[][2] = {
	{ ROADSIDE_GRASS,         ROADSIDE_GRASS },
	{ ROADSIDE_PAVED,         ROADSIDE_PAVED },
	{ ROADSIDE_PAVED,         ROADSIDE_PAVED },
	{ ROADSIDE_TREES,         ROADSIDE_TREES },
	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED }
};

static const Roadside _town_road_types_2[][2] = {
	{ ROADSIDE_GRASS,         ROADSIDE_GRASS },
	{ ROADSIDE_PAVED,         ROADSIDE_PAVED },
	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED },
	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED },
	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED }
};


static void TileLoop_Road(TileIndex tile)
{
	switch (_opt.landscape) {
		case LT_ARCTIC:
			if (IsOnSnow(tile) != (GetTileZ(tile) > GetSnowLine())) {
				ToggleSnow(tile);
				MarkTileDirtyByTile(tile);
			}
			break;

		case LT_TROPIC:
			if (GetTropicZone(tile) == TROPICZONE_DESERT && !IsOnDesert(tile)) {
				ToggleDesert(tile);
				MarkTileDirtyByTile(tile);
			}
			break;
	}

	if (IsRoadDepot(tile)) return;

	const Town *t = ClosestTownFromTile(tile, (uint)-1);
	if (!HasRoadWorks(tile)) {
		HouseZonesBits grp = HZB_TOWN_EDGE;

		if (t != NULL) {
			grp = GetTownRadiusGroup(t, tile);

			/* Show an animation to indicate road work */
			if (t->road_build_months != 0 &&
					(DistanceManhattan(t->xy, tile) < 8 || grp != HZB_TOWN_EDGE) &&
					IsNormalRoad(tile) && CountBits(GetAllRoadBits(tile)) > 1 ) {
				if (GetTileSlope(tile, NULL) == SLOPE_FLAT && EnsureNoVehicleOnGround(tile) && Chance16(1, 40)) {
					StartRoadWorks(tile);

					SndPlayTileFx(SND_21_JACKHAMMER, tile);
					CreateEffectVehicleAbove(
						TileX(tile) * TILE_SIZE + 7,
						TileY(tile) * TILE_SIZE + 7,
						0,
						EV_BULLDOZER);
					MarkTileDirtyByTile(tile);
					return;
				}
			}
		}

		{
			/* Adjust road ground type depending on 'grp' (grp is the distance to the center) */
			const Roadside* new_rs = (_opt.landscape == LT_TOYLAND) ? _town_road_types_2[grp] : _town_road_types[grp];
			Roadside cur_rs = GetRoadside(tile);

			/* We have our desired type, do nothing */
			if (cur_rs == new_rs[0]) return;

			/* We have the pre-type of the desired type, switch to the desired type */
			if (cur_rs == new_rs[1]) {
				cur_rs = new_rs[0];
			/* We have barren land, install the pre-type */
			} else if (cur_rs == ROADSIDE_BARREN) {
				cur_rs = new_rs[1];
			/* We're totally off limits, remove any installation and make barren land */
			} else {
				cur_rs = ROADSIDE_BARREN;
			}
			SetRoadside(tile, cur_rs);
			MarkTileDirtyByTile(tile);
		}
	} else if (IncreaseRoadWorksCounter(tile)) {
		TerminateRoadWorks(tile);

		if (_patches.mod_road_rebuild) {
			/* Generate a nicer town surface */
			const RoadBits old_rb = GetAnyRoadBits(tile, ROADTYPE_ROAD);
			const RoadBits new_rb = CleanUpRoadBits(tile, old_rb);

			if (old_rb != new_rb) {
				RemoveRoad(tile, DC_EXEC | DC_AUTO | DC_NO_WATER, (old_rb ^ new_rb), ROADTYPE_ROAD, true);
			}
		}

		MarkTileDirtyByTile(tile);
	}
}

static void ClickTile_Road(TileIndex tile)
{
	if (IsRoadDepot(tile)) ShowDepotWindow(tile, VEH_ROAD);
}

/* Converts RoadBits to TrackBits */
static const byte _road_trackbits[16] = {
	0x0, 0x0, 0x0, 0x10, 0x0, 0x2, 0x8, 0x1A, 0x0, 0x4, 0x1, 0x15, 0x20, 0x26, 0x29, 0x3F,
};

static TrackStatus GetTileTrackStatus_Road(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
{
	TrackdirBits trackdirbits = TRACKDIR_BIT_NONE;
	TrackdirBits red_signals = TRACKDIR_BIT_NONE; // crossing barred
	switch (mode) {
		case TRANSPORT_RAIL:
			if (IsLevelCrossing(tile)) trackdirbits = TrackBitsToTrackdirBits(GetCrossingRailBits(tile));
			break;

		case TRANSPORT_ROAD:
			if ((GetRoadTypes(tile) & sub_mode) == 0) break;
			switch (GetRoadTileType(tile)) {
				case ROAD_TILE_NORMAL: {
					const uint drd_to_multiplier[DRD_END] = { 0x101, 0x100, 0x1, 0x0 };
					RoadType rt = (RoadType)FindFirstBit(sub_mode);
					RoadBits bits = GetRoadBits(tile, rt);

					/* no roadbit at this side of tile, return 0 */
					if (side != INVALID_DIAGDIR && (DiagDirToRoadBits(side) & bits) == 0) break;

					uint multiplier = drd_to_multiplier[rt == ROADTYPE_TRAM ? DRD_NONE : GetDisallowedRoadDirections(tile)];
					if (!HasRoadWorks(tile)) trackdirbits = (TrackdirBits)(_road_trackbits[bits] * multiplier);
					break;
				}

				case ROAD_TILE_CROSSING: {
					Axis axis = GetCrossingRoadAxis(tile);

					if (side != INVALID_DIAGDIR && axis != DiagDirToAxis(side)) break;

					trackdirbits = TrackBitsToTrackdirBits(AxisToTrackBits(axis));
					if (IsCrossingBarred(tile)) red_signals = trackdirbits;
					break;
				}

				default:
				case ROAD_TILE_DEPOT: {
					DiagDirection dir = GetRoadDepotDirection(tile);

					if (side != INVALID_DIAGDIR && side != dir) break;

					trackdirbits = TrackBitsToTrackdirBits(AxisToTrackBits(DiagDirToAxis(dir)));
					break;
				}
			}
			break;

		default: break;
	}
	return CombineTrackStatus(trackdirbits, red_signals);
}

static const StringID _road_tile_strings[] = {
	STR_1814_ROAD,
	STR_1814_ROAD,
	STR_1814_ROAD,
	STR_1815_ROAD_WITH_STREETLIGHTS,
	STR_1814_ROAD,
	STR_1816_TREE_LINED_ROAD,
	STR_1814_ROAD,
	STR_1814_ROAD,
};

static void GetTileDesc_Road(TileIndex tile, TileDesc *td)
{
	td->owner = GetTileOwner(tile);
	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_CROSSING: td->str = STR_1818_ROAD_RAIL_LEVEL_CROSSING; break;
		case ROAD_TILE_DEPOT: td->str = STR_1817_ROAD_VEHICLE_DEPOT; break;
		default: td->str = _road_tile_strings[GetRoadside(tile)]; break;
	}
}

/**
 * Given the direction the road depot is pointing, this is the direction the
 * vehicle should be travelling in in order to enter the depot.
 */
static const byte _roadveh_enter_depot_dir[4] = {
	TRACKDIR_X_SW, TRACKDIR_Y_NW, TRACKDIR_X_NE, TRACKDIR_Y_SE
};

static VehicleEnterTileStatus VehicleEnter_Road(Vehicle *v, TileIndex tile, int x, int y)
{
	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_CROSSING:
			if (v->type == VEH_TRAIN) {
				/* it should be barred */
				assert(IsCrossingBarred(tile));
			}
			break;

		case ROAD_TILE_DEPOT:
			if (v->type == VEH_ROAD &&
					v->u.road.frame == 11 &&
					_roadveh_enter_depot_dir[GetRoadDepotDirection(tile)] == v->u.road.state) {
				v->u.road.state = RVSB_IN_DEPOT;
				v->vehstatus |= VS_HIDDEN;
				v->direction = ReverseDir(v->direction);
				if (v->Next() == NULL) VehicleEnterDepot(v);
				v->tile = tile;

				InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
				return VETSB_ENTERED_WORMHOLE;
			}
			break;

		default: break;
	}
	return VETSB_CONTINUE;
}


static void ChangeTileOwner_Road(TileIndex tile, PlayerID old_player, PlayerID new_player)
{
	if (IsRoadDepot(tile)) {
		if (GetTileOwner(tile) == old_player) {
			if (new_player == PLAYER_SPECTATOR) {
				DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR);
			} else {
				SetTileOwner(tile, new_player);
			}
		}
		return;
	}

	for (RoadType rt = ROADTYPE_ROAD; rt < ROADTYPE_END; rt++) {
		/* ROADTYPE_ROAD denotes the tile owner, so update it too */
		if (rt != ROADTYPE_ROAD && !HasTileRoadType(tile, rt)) continue;

		if (GetRoadOwner(tile, rt) == old_player) {
			SetRoadOwner(tile, rt, new_player == PLAYER_SPECTATOR ? OWNER_NONE : new_player);
		}
	}

	if (IsLevelCrossing(tile)) {
		if (GetTileOwner(tile) == old_player) {
			if (new_player == PLAYER_SPECTATOR) {
				DoCommand(tile, 0, GetCrossingRailTrack(tile), DC_EXEC | DC_BANKRUPT, CMD_REMOVE_SINGLE_RAIL);
			} else {
				SetTileOwner(tile, new_player);
			}
		}
	}
}

static CommandCost TerraformTile_Road(TileIndex tile, uint32 flags, uint z_new, Slope tileh_new)
{
	if (_patches.build_on_slopes && AutoslopeEnabled()) {
		switch (GetRoadTileType(tile)) {
			case ROAD_TILE_CROSSING:
				if (!IsSteepSlope(tileh_new) && (GetTileMaxZ(tile) == z_new + GetSlopeMaxZ(tileh_new)) && HasBit(VALID_LEVEL_CROSSING_SLOPES, tileh_new)) return CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);
				break;

			case ROAD_TILE_DEPOT:
				if (AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRoadDepotDirection(tile))) return CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);
				break;

			case ROAD_TILE_NORMAL: {
				RoadBits bits = GetAllRoadBits(tile);
				RoadBits bits_copy = bits;
				/* Check if the slope-road_bits combination is valid at all, i.e. it is save to call GetRoadFoundation(). */
				if (!CmdFailed(CheckRoadSlope(tileh_new, &bits_copy, ROAD_NONE, ROAD_NONE))) {
					/* CheckRoadSlope() sometimes changes the road_bits, if it does not agree with them. */
					if (bits == bits_copy) {
						uint z_old;
						Slope tileh_old = GetTileSlope(tile, &z_old);

						/* Get the slope on top of the foundation */
						z_old += ApplyFoundationToSlope(GetRoadFoundation(tileh_old, bits), &tileh_old);
						z_new += ApplyFoundationToSlope(GetRoadFoundation(tileh_new, bits), &tileh_new);

						/* The surface slope must not be changed */
						if ((z_old == z_new) && (tileh_old == tileh_new)) return CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);
					}
				}
				break;
			}

			default: NOT_REACHED();
		}
	}

	return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
}


extern const TileTypeProcs _tile_type_road_procs = {
	DrawTile_Road,           /* draw_tile_proc */
	GetSlopeZ_Road,          /* get_slope_z_proc */
	ClearTile_Road,          /* clear_tile_proc */
	GetAcceptedCargo_Road,   /* get_accepted_cargo_proc */
	GetTileDesc_Road,        /* get_tile_desc_proc */
	GetTileTrackStatus_Road, /* get_tile_track_status_proc */
	ClickTile_Road,          /* click_tile_proc */
	AnimateTile_Road,        /* animate_tile_proc */
	TileLoop_Road,           /* tile_loop_clear */
	ChangeTileOwner_Road,    /* change_tile_owner_clear */
	NULL,                    /* get_produced_cargo_proc */
	VehicleEnter_Road,       /* vehicle_enter_tile_proc */
	GetFoundation_Road,      /* get_foundation_proc */
	TerraformTile_Road,      /* terraform_tile_proc */
};