text: # if 0
  /* $Id: station_cmd.c 3341 2005-12-25 15:05:59Z truelight $ */
  
  /** @file station_cmd.c
    */
  
  #include "stdafx.h"
  #include "openttd.h"
  #include "debug.h"
  #include "functions.h"
  #include "table/sprites.h"
  #include "table/strings.h"
  #include "map.h"
  #include "tile.h"
  #include "station.h"
  #include "gfx.h"
  #include "window.h"
  #include "viewport.h"
  #include "command.h"
  #include "town.h"
  #include "vehicle.h"
  #include "news.h"
  #include "saveload.h"
  #include "economy.h"
  #include "player.h"
  #include "airport.h"
  #include "sprite.h"
  #include "depot.h"
  #include "pbs.h"
  #include "train.h"
  
  enum {
  	/* Max stations: 64000 (64 * 1000) */
  	STATION_POOL_BLOCK_SIZE_BITS = 6,       /* In bits, so (1 << 6) == 64 */
  	STATION_POOL_MAX_BLOCKS      = 1000,
  
  	/* Max roadstops: 64000 (32 * 2000) */
  	ROADSTOP_POOL_BLOCK_SIZE_BITS = 5,       /* In bits, so (1 << 5) == 32 */
  	ROADSTOP_POOL_MAX_BLOCKS      = 2000,
  };
  
  /**
   * Called if a new block is added to the station-pool
   */
  static void StationPoolNewBlock(uint start_item)
  {
  	Station *st;
  
  	FOR_ALL_STATIONS_FROM(st, start_item) st->index = start_item++;
  }
  
  /**
   * Called if a new block is added to the roadstop-pool
   */
  static void RoadStopPoolNewBlock(uint start_item)
  {
  	RoadStop *rs;
  
  	FOR_ALL_ROADSTOPS_FROM(rs, start_item) rs->index = start_item++;
  }
  
  /* Initialize the station-pool and roadstop-pool */
  //MemoryPool _station_pool = { "Stations", STATION_POOL_MAX_BLOCKS, STATION_POOL_BLOCK_SIZE_BITS, sizeof(Station), &StationPoolNewBlock, 0, 0, NULL };
  //MemoryPool _roadstop_pool = { "RoadStop", ROADSTOP_POOL_MAX_BLOCKS, ROADSTOP_POOL_BLOCK_SIZE_BITS, sizeof(RoadStop), &RoadStopPoolNewBlock, 0, 0, NULL };
  
  
  // FIXME -- need to be embedded into Airport variable. Is dynamically
  // deducteable from graphics-tile array, so will not be needed
  const byte _airport_size_x[] = {4, 6, 1, 6, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
  const byte _airport_size_y[] = {3, 6, 1, 6, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
  
  void ShowAircraftDepotWindow(TileIndex tile);
  extern void UpdateAirplanesOnNewStation(Station *st);
  
  static void MarkStationDirty(const Station* st)
  {
  	if (st->sign.width_1 != 0) {
  		InvalidateWindowWidget(WC_STATION_VIEW, st->index, 1);
  
  		MarkAllViewportsDirty(
  			st->sign.left - 6,
  			st->sign.top,
  			st->sign.left + (st->sign.width_1 << 2) + 12,
  			st->sign.top + 48);
  	}
  }
  /*
  static void InitializeRoadStop(RoadStop *road_stop, RoadStop *previous, TileIndex tile, StationID index)
  {
  	road_stop->xy = tile;
  	road_stop->used = true;
  	road_stop->status = 3; //stop is free
  	road_stop->slot[0] = road_stop->slot[1] = INVALID_SLOT;
  	road_stop->next = NULL;
  	road_stop->prev = previous;
  	road_stop->station = index;
  }
  
  RoadStop* GetPrimaryRoadStop(const Station* st, RoadStopType type)
  {
  	switch (type) {
  		case RS_BUS:   return st->bus_stops;
  		case RS_TRUCK: return st->truck_stops;
  		default: NOT_REACHED();
  	}
  
  	return NULL;
  }
  
  RoadStop* GetRoadStopByTile(TileIndex tile, RoadStopType type)
  {
  	const Station* st = GetStation(_m[tile].m2);
  	RoadStop* rs;
  
  	for (rs = GetPrimaryRoadStop(st, type); rs->xy != tile; rs = rs->next) {
  		assert(rs->next != NULL);
  	}
  
  	return rs;
  }
  
  uint GetNumRoadStops(const Station *st, RoadStopType type)
  {
  	uint num = 0;
  	const RoadStop *rs;
  
  	assert(st != NULL);
  	for (rs = GetPrimaryRoadStop(st, type); rs != NULL; rs = rs->next) num++;
  
  	return num;
  }
  
  RoadStop *AllocateRoadStop(void)
  {
  	RoadStop *rs;
  
  	FOR_ALL_ROADSTOPS(rs) {
  		if (!rs->used) {
  			uint index = rs->index;
  
  			memset(rs, 0, sizeof(*rs));
  			rs->index = index;
  
  			return rs;
  		}
  	}
  
  	/* Check if we can add a block to the pool * /
  	if (AddBlockToPool(&_roadstop_pool)) return AllocateRoadStop();
  
  	return NULL;
  }
  */
  /* Calculate the radius of the station. Basicly it is the biggest
      radius that is available within the station */
  static uint FindCatchmentRadius(const Station* st)
  {
  	uint ret = 0;
  
  	if (st->bus_stops != NULL)   ret = max(ret, CA_BUS);
  	if (st->truck_stops != NULL) ret = max(ret, CA_TRUCK);
  	if (st->train_tile) ret = max(ret, CA_TRAIN);
  	if (st->dock_tile)  ret = max(ret, CA_DOCK);
  
  	if (st->airport_tile) {
  		switch (st->airport_type) {
  			case AT_OILRIG:        ret = max(ret, CA_AIR_OILPAD);   break;
  			case AT_SMALL:         ret = max(ret, CA_AIR_SMALL);    break;
  			case AT_HELIPORT:      ret = max(ret, CA_AIR_HELIPORT); break;
  			case AT_LARGE:         ret = max(ret, CA_AIR_LARGE);    break;
  			case AT_METROPOLITAN:  ret = max(ret, CA_AIR_METRO);    break;
  			case AT_INTERNATIONAL: ret = max(ret, CA_AIR_INTER);    break;
  		}
  	}
  
  	return ret;
  }
  
  #define CHECK_STATIONS_ERR ((Station*)-1)
  
  static Station* GetStationAround(TileIndex tile, int w, int h, StationID closest_station)
  {
  	// check around to see if there's any stations there
  	BEGIN_TILE_LOOP(tile_cur, w + 2, h + 2, tile - TileDiffXY(1, 1))
  		if (IsTileType(tile_cur, MP_STATION)) {
  			StationID t = _m[tile_cur].m2;
  			{
  				Station *st = GetStation(t);
  				// you cannot take control of an oilrig!!
  				if (st->airport_type == AT_OILRIG && st->facilities == (FACIL_AIRPORT|FACIL_DOCK))
  					continue;
  			}
  
  			if (closest_station == INVALID_STATION) {
  				closest_station = t;
  			} else if (closest_station != t) {
  				_error_message = STR_3006_ADJOINS_MORE_THAN_ONE_EXISTING;
  				return CHECK_STATIONS_ERR;
  			}
  		}
  	END_TILE_LOOP(tile_cur, w + 2, h + 2, tile - TileDiffXY(1, 1))
  	return (closest_station == INVALID_STATION) ? NULL : GetStation(closest_station);
  }
  
  TileIndex GetStationTileForVehicle(const Vehicle *v, const Station *st)
  {
  	switch (v->type) {
  		case VEH_Train: 		return st->train_tile;
  		case VEH_Aircraft:	return st->airport_tile;
  		case VEH_Ship:			return st->dock_tile;
  		case VEH_Road:
  			if (v->cargo_type == CT_PASSENGERS) {
  				return (st->bus_stops != NULL) ? st->bus_stops->xy : 0;
  			} else {
  				return (st->truck_stops != NULL) ? st->truck_stops->xy : 0;
  			}
  		default:
  			assert(false);
  			return 0;
  	}
  }
  
  static bool CheckStationSpreadOut(Station *st, TileIndex tile, int w, int h)
  {
  	StationID station_index = st->index;
  	uint i;
  	uint x1 = TileX(tile);
  	uint y1 = TileY(tile);
  	uint x2 = x1 + w - 1;
  	uint y2 = y1 + h - 1;
  	uint t;
  
  	for (i = 0; i != MapSize(); i++) {
  		if (IsTileType(i, MP_STATION) && _m[i].m2 == station_index) {
  			t = TileX(i);
  			if (t < x1) x1 = t;
  			if (t > x2) x2 = t;
  
  			t = TileY(i);
  			if (t < y1) y1 = t;
  			if (t > y2) y2 = t;
  		}
  	}
  
  	if (y2 - y1 >= _patches.station_spread || x2 - x1 >= _patches.station_spread) {
  		_error_message = STR_306C_STATION_TOO_SPREAD_OUT;
  		return false;
  	}
  
  	return true;
  }
  
  static Station *AllocateStation(void)
  {
  	Station *st = NULL;
  
  	FOR_ALL_STATIONS(st) {
  		if (st->xy == 0) {
  			StationID index = st->index;
  
  			memset(st, 0, sizeof(Station));
  			st->index = index;
  
  			return st;
  		}
  	}
  
  	/* Check if we can add a block to the pool */
  	if (AddBlockToPool(&_station_pool)) return AllocateStation();
  
  	_error_message = STR_3008_TOO_MANY_STATIONS_LOADING;
  	return NULL;
  }
  
  
  static int CountMapSquareAround(TileIndex tile, byte type, byte min, byte max)
  {
  	static const TileIndexDiffC _count_square_table[] = {
  		{-3, -3}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0},
  		{-6,  1}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0},
  		{-6,  1}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0},
  		{-6,  1}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0},
  		{-6,  1}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0},
  		{-6,  1}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0},
  		{-6,  1}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0}, {1, 0}
  	};
  	const TileIndexDiffC *p;
  	int num = 0;
  
  	for (p = _count_square_table; p != endof(_count_square_table); ++p) {
  		tile = TILE_MASK(tile + ToTileIndexDiff(*p));
  
  		if (IsTileType(tile, type) && _m[tile].m5 >= min && _m[tile].m5 <= max)
  			num++;
  	}
  
  	return num;
  }
  
  #define M(x) ((x) - STR_SV_STNAME)
  
  static bool GenerateStationName(Station *st, TileIndex tile, int flag)
  {
  	static const uint32 _gen_station_name_bits[] = {
  		0,                                      /* 0 */
  		1 << M(STR_SV_STNAME_AIRPORT),          /* 1 */
  		1 << M(STR_SV_STNAME_OILFIELD),         /* 2 */
  		1 << M(STR_SV_STNAME_DOCKS),            /* 3 */
  		0x1FF << M(STR_SV_STNAME_BUOY_1),       /* 4 */
  		1 << M(STR_SV_STNAME_HELIPORT),         /* 5 */
  	};
  
  	Town *t = st->town;
  	uint32 free_names = (uint32)-1;
  	int found;
  	uint z,z2;
  	unsigned long tmp;
  
  	{
  		Station *s;
  
  		FOR_ALL_STATIONS(s) {
  			if (s != st && s->xy != 0 && s->town==t) {
  				uint str = M(s->string_id);
  				if (str <= 0x20) {
  					if (str == M(STR_SV_STNAME_FOREST))
  						str = M(STR_SV_STNAME_WOODS);
  					CLRBIT(free_names, str);
  				}
  			}
  		}
  	}
  
  	/* check default names */
  	tmp = free_names & _gen_station_name_bits[flag];
  	if (tmp != 0) {
  		found = FindFirstBit(tmp);
  		goto done;
  	}
  
  	/* check mine? */
  	if (HASBIT(free_names, M(STR_SV_STNAME_MINES))) {
  		if (CountMapSquareAround(tile, MP_INDUSTRY, 0, 6) >= 2 ||
  				CountMapSquareAround(tile, MP_INDUSTRY, 0x64, 0x73) >= 2 ||
  				CountMapSquareAround(tile, MP_INDUSTRY, 0x2F, 0x33) >= 2 ||
  				CountMapSquareAround(tile, MP_INDUSTRY, 0x48, 0x58) >= 2 ||
  				CountMapSquareAround(tile, MP_INDUSTRY, 0x5B, 0x63) >= 2) {
  			found = M(STR_SV_STNAME_MINES);
  			goto done;
  		}
  	}
  
  	/* check close enough to town to get central as name? */
  	if (DistanceMax(tile,t->xy) < 8) {
  		found = M(STR_SV_STNAME);
  		if (HASBIT(free_names, M(STR_SV_STNAME))) goto done;
  
  		found = M(STR_SV_STNAME_CENTRAL);
  		if (HASBIT(free_names, M(STR_SV_STNAME_CENTRAL))) goto done;
  	}
  
  	/* Check lakeside */
  	if (HASBIT(free_names, M(STR_SV_STNAME_LAKESIDE)) &&
  			DistanceFromEdge(tile) < 20 &&
  			CountMapSquareAround(tile, MP_WATER, 0, 0) >= 5) {
  		found = M(STR_SV_STNAME_LAKESIDE);
  		goto done;
  	}
  
  	/* Check woods */
  	if (HASBIT(free_names, M(STR_SV_STNAME_WOODS)) && (
  				CountMapSquareAround(tile, MP_TREES, 0, 255) >= 8 ||
  				CountMapSquareAround(tile, MP_INDUSTRY, 0x10, 0x11) >= 2)
  			) {
  		found = _opt.landscape == LT_DESERT ?
  			M(STR_SV_STNAME_FOREST) : M(STR_SV_STNAME_WOODS);
  		goto done;
  	}
  
  	/* check elevation compared to town */
  	z = GetTileZ(tile);
  	z2 = GetTileZ(t->xy);
  	if (z < z2) {
  		found = M(STR_SV_STNAME_VALLEY);
  		if (HASBIT(free_names, M(STR_SV_STNAME_VALLEY))) goto done;
  	} else if (z > z2) {
  		found = M(STR_SV_STNAME_HEIGHTS);
  		if (HASBIT(free_names, M(STR_SV_STNAME_HEIGHTS))) goto done;
  	}
  
  	/* check direction compared to town */
  	{
  		static const int8 _direction_and_table[] = {
  			~( (1<<M(STR_SV_STNAME_WEST)) | (1<<M(STR_SV_STNAME_EAST)) | (1<<M(STR_SV_STNAME_NORTH)) ),
  			~( (1<<M(STR_SV_STNAME_SOUTH)) | (1<<M(STR_SV_STNAME_WEST)) | (1<<M(STR_SV_STNAME_NORTH)) ),
  			~( (1<<M(STR_SV_STNAME_SOUTH)) | (1<<M(STR_SV_STNAME_EAST)) | (1<<M(STR_SV_STNAME_NORTH)) ),
  			~( (1<<M(STR_SV_STNAME_SOUTH)) | (1<<M(STR_SV_STNAME_WEST)) | (1<<M(STR_SV_STNAME_EAST)) ),
  		};
  
  		free_names &= _direction_and_table[
  			(TileX(tile) < TileX(t->xy)) +
  			(TileY(tile) < TileY(t->xy)) * 2];
  	}
  
  	tmp = free_names & ((1<<1)|(1<<2)|(1<<3)|(1<<4)|(1<<6)|(1<<7)|(1<<12)|(1<<26)|(1<<27)|(1<<28)|(1<<29)|(1<<30));
  	if (tmp == 0) {
  		_error_message = STR_3007_TOO_MANY_STATIONS_LOADING;
  		return false;
  	}
  	found = FindFirstBit(tmp);
  
  done:
  	st->string_id = found + STR_SV_STNAME;
  	return true;
  }
  #undef M
  
  static Station* GetClosestStationFromTile(TileIndex tile, uint threshold, PlayerID owner)
  {
  	Station* best_station = NULL;
  	Station* st;
  
  	FOR_ALL_STATIONS(st) {
  		if (st->xy != 0 && (owner == OWNER_SPECTATOR || st->owner == owner)) {
  			uint cur_dist = DistanceManhattan(tile, st->xy);
  
  			if (cur_dist < threshold) {
  				threshold = cur_dist;
  				best_station = st;
  			}
  		}
  	}
  
  	return best_station;
  }
  /*
  static void StationInitialize(Station *st, TileIndex tile)
  {
  	GoodsEntry *ge;
  
  	st->xy = tile;
  	st->airport_tile = st->dock_tile = st->train_tile = 0;
  	st->bus_stops = st->truck_stops = NULL;
  	st->had_vehicle_of_type = 0;
  	st->time_since_load = 255;
  	st->time_since_unload = 255;
  	st->delete_ctr = 0;
  	st->facilities = 0;
  
  	st->last_vehicle = INVALID_VEHICLE;
  
  	for (ge = st->goods; ge != endof(st->goods); ge++) {
  		ge->waiting_acceptance = 0;
  		ge->days_since_pickup = 0;
  		ge->enroute_from = INVALID_STATION;
  		ge->rating = 175;
  		ge->last_speed = 0;
  		ge->last_age = 0xFF;
  		ge->feeder_profit = 0;
  	}
  
  	st->airport_queue = new_VQueue();
  	st->helicopter_queue = new_VQueue();
  
  	_global_station_sort_dirty = true; // build a new station
  }
  
  // Update the virtual coords needed to draw the station sign.
  // st = Station to update for.
  static void UpdateStationVirtCoord(Station *st)
  {
  	Point pt = RemapCoords2(TileX(st->xy) * 16, TileY(st->xy) * 16);
  
  	pt.y -= 32;
  	if (st->facilities & FACIL_AIRPORT && st->airport_type == AT_OILRIG) pt.y -= 16;
  
  	SetDParam(0, st->index);
  	SetDParam(1, st->facilities);
  	UpdateViewportSignPos(&st->sign, pt.x, pt.y, STR_305C_0);
  }
  
  // Update the virtual coords needed to draw the station sign for all stations.
  void UpdateAllStationVirtCoord(void)
  {
  	Station* st;
  
  	FOR_ALL_STATIONS(st) {
  		if (st->xy != 0) UpdateStationVirtCoord(st);
  	}
  }
  
  // Update the station virt coords while making the modified parts dirty.
  static void UpdateStationVirtCoordDirty(Station *st)
  {
  	MarkStationDirty(st);
  	UpdateStationVirtCoord(st);
  	MarkStationDirty(st);
  }
  
  // Get a mask of the cargo types that the station accepts.
  static uint GetAcceptanceMask(const Station *st)
  {
  	uint mask = 0;
  	uint i;
  
  	for (i = 0; i != NUM_CARGO; i++) {
  		if (st->goods[i].waiting_acceptance & 0x8000) mask |= 1 << i;
  	}
  	return mask;
  }
  
  // Items contains the two cargo names that are to be accepted or rejected.
  // msg is the string id of the message to display.
  static void ShowRejectOrAcceptNews(const Station *st, uint32 items, StringID msg)
  {
  	if (items) {
  		SetDParam(2, GB(items, 16, 16));
  		SetDParam(1, GB(items,  0, 16));
  		SetDParam(0, st->index);
  		AddNewsItem(msg + ((items >> 16)?1:0), NEWS_FLAGS(NM_SMALL, NF_VIEWPORT|NF_TILE, NT_ACCEPTANCE, 0), st->xy, 0);
  	}
  }
  
  // Get a list of the cargo types being produced around the tile.
  void GetProductionAroundTiles(AcceptedCargo produced, TileIndex tile,
  	int w, int h, int rad)
  {
  	int x,y;
  	int x1,y1,x2,y2;
  	int xc,yc;
  
  	memset(produced, 0, sizeof(AcceptedCargo));
  
  	x = TileX(tile);
  	y = TileY(tile);
  
  	// expand the region by rad tiles on each side
  	// while making sure that we remain inside the board.
  	x2 = min(x + w + rad, MapSizeX());
  	x1 = max(x - rad, 0);
  
  	y2 = min(y + h + rad, MapSizeY());
  	y1 = max(y - rad, 0);
  
  	assert(x1 < x2);
  	assert(y1 < y2);
  	assert(w > 0);
  	assert(h > 0);
  
  	for (yc = y1; yc != y2; yc++) {
  		for (xc = x1; xc != x2; xc++) {
  			if (!(IS_INSIDE_1D(xc, x, w) && IS_INSIDE_1D(yc, y, h))) {
  				GetProducedCargoProc *gpc;
  				TileIndex tile = TileXY(xc, yc);
  
  				gpc = _tile_type_procs[GetTileType(tile)]->get_produced_cargo_proc;
  				if (gpc != NULL) {
  					byte cargos[2] = { CT_INVALID, CT_INVALID };
  
  					gpc(tile, cargos);
  					if (cargos[0] != CT_INVALID) {
  						produced[cargos[0]]++;
  						if (cargos[1] != CT_INVALID) {
  							produced[cargos[1]]++;
  						}
  					}
  				}
  			}
  		}
  	}
  }
  
  // Get a list of the cargo types that are accepted around the tile.
  void GetAcceptanceAroundTiles(AcceptedCargo accepts, TileIndex tile,
  	int w, int h, int rad)
  {
  	int x,y;
  	int x1,y1,x2,y2;
  	int xc,yc;
  
  	memset(accepts, 0, sizeof(AcceptedCargo));
  
  	x = TileX(tile);
  	y = TileY(tile);
  
  	// expand the region by rad tiles on each side
  	// while making sure that we remain inside the board.
  	x2 = min(x + w + rad, MapSizeX());
  	y2 = min(y + h + rad, MapSizeY());
  	x1 = max(x - rad, 0);
  	y1 = max(y - rad, 0);
  
  	assert(x1 < x2);
  	assert(y1 < y2);
  	assert(w > 0);
  	assert(h > 0);
  
  	for (yc = y1; yc != y2; yc++) {
  		for (xc = x1; xc != x2; xc++) {
  			TileIndex tile = TileXY(xc, yc);
  
  			if (!IsTileType(tile, MP_STATION)) {
  				AcceptedCargo ac;
  				uint i;
  
  				GetAcceptedCargo(tile, ac);
  				for (i = 0; i < lengthof(ac); ++i) accepts[i] += ac[i];
  			}
  		}
  	}
  }
  
  typedef struct ottd_Rectangle {
  	uint min_x;
  	uint min_y;
  	uint max_x;
  	uint max_y;
  } ottd_Rectangle;
  
  static void MergePoint(ottd_Rectangle* rect, TileIndex tile)
  {
  	uint x = TileX(tile);
  	uint y = TileY(tile);
  
  	if (rect->min_x > x) rect->min_x = x;
  	if (rect->min_y > y) rect->min_y = y;
  	if (rect->max_x < x) rect->max_x = x;
  	if (rect->max_y < y) rect->max_y = y;
  }
  
  
  // Update the acceptance for a station.
  // show_msg controls whether to display a message that acceptance was changed.
  static void UpdateStationAcceptance(Station *st, bool show_msg)
  {
  	uint old_acc, new_acc;
  	const RoadStop *cur_rs;
  	int i;
  	ottd_Rectangle rect;
  	int rad;
  	AcceptedCargo accepts;
  
  	rect.min_x = MapSizeX();
  	rect.min_y = MapSizeY();
  	rect.max_x = rect.max_y = 0;
  	// Don't update acceptance for a buoy
  	if (IsBuoy(st)) return;
  
  	/* old accepted goods types * /
  	old_acc = GetAcceptanceMask(st);
  
  	// Put all the tiles that span an area in the table.
  	if (st->train_tile != 0) {
  		MergePoint(&rect, st->train_tile);
  		MergePoint(&rect,
  			st->train_tile + TileDiffXY(st->trainst_w - 1, st->trainst_h - 1)
  		);
  	}
  
  	if (st->airport_tile != 0) {
  		MergePoint(&rect, st->airport_tile);
  		MergePoint(&rect,
  			st->airport_tile + TileDiffXY(
  				_airport_size_x[st->airport_type] - 1,
  				_airport_size_y[st->airport_type] - 1
  			)
  		);
  	}
  
  	if (st->dock_tile != 0) MergePoint(&rect, st->dock_tile);
  
  	for (cur_rs = st->bus_stops; cur_rs != NULL; cur_rs = cur_rs->next) {
  		MergePoint(&rect, cur_rs->xy);
  	}
  
  	for (cur_rs = st->truck_stops; cur_rs != NULL; cur_rs = cur_rs->next) {
  		MergePoint(&rect, cur_rs->xy);
  	}
  
  	rad = (_patches.modified_catchment) ? FindCatchmentRadius(st) : 4;
  
  	// And retrieve the acceptance.
  	if (rect.max_x >= rect.min_x) {
  		GetAcceptanceAroundTiles(
  			accepts,
  			TileXY(rect.min_x, rect.min_y),
  			rect.max_x - rect.min_x + 1,
  			rect.max_y - rect.min_y + 1,
  			rad
  		);
  	} else {
  		memset(accepts, 0, sizeof(accepts));
  	}
  
  	// Adjust in case our station only accepts fewer kinds of goods
  	for (i = 0; i != NUM_CARGO; i++) {
  		uint amt = min(accepts[i], 15);
  
  		// Make sure the station can accept the goods type.
  		if ((i != CT_PASSENGERS && !(st->facilities & (byte)~FACIL_BUS_STOP)) ||
  				(i == CT_PASSENGERS && !(st->facilities & (byte)~FACIL_TRUCK_STOP)))
  			amt = 0;
  
  		SB(st->goods[i].waiting_acceptance, 12, 4, amt);
  	}
  
  	// Only show a message in case the acceptance was actually changed.
  	new_acc = GetAcceptanceMask(st);
  	if (old_acc == new_acc)
  		return;
  
  	// show a message to report that the acceptance was changed?
  	if (show_msg && st->owner == _local_player && st->facilities) {
  		uint32 accept=0, reject=0; /* these contain two string ids each * /
  		const StringID *str = _cargoc.names_s;
  
  		do {
  			if (new_acc & 1) {
  				if (!(old_acc & 1)) accept = (accept << 16) | *str;
  			} else {
  				if (old_acc & 1) reject = (reject << 16) | *str;
  			}
  		} while (str++,(new_acc>>=1) != (old_acc>>=1));
  
  		ShowRejectOrAcceptNews(st, accept, STR_3040_NOW_ACCEPTS);
  		ShowRejectOrAcceptNews(st, reject, STR_303E_NO_LONGER_ACCEPTS);
  	}
  
  	// redraw the station view since acceptance changed
  	InvalidateWindowWidget(WC_STATION_VIEW, st->index, 4);
  }
  
  // This is called right after a station was deleted.
  // It checks if the whole station is free of substations, and if so, the station will be
  // deleted after a little while.
  static void DeleteStationIfEmpty(Station* st)
  {
  	if (st->facilities == 0) {
  		st->delete_ctr = 0;
  		InvalidateWindow(WC_STATION_LIST, st->owner);
  	}
  }
  */
  
  static int32 ClearTile_Station(TileIndex tile, byte flags);
  
  // Tries to clear the given area. Returns the cost in case of success.
  // Or an error code if it failed.
  int32 CheckFlatLandBelow(TileIndex tile, uint w, uint h, uint flags, uint invalid_dirs, StationID* station)
  {
  	int32 cost = 0, ret;
  
  	uint tileh;
  	uint z;
  	int allowed_z = -1;
  	int flat_z;
  
  	BEGIN_TILE_LOOP(tile_cur, w, h, tile)
  		if (!EnsureNoVehicle(tile_cur)) return CMD_ERROR;
  
  		tileh = GetTileSlope(tile_cur, &z);
  
  		/* Prohibit building if
  			1) The tile is "steep" (i.e. stretches two height levels)
  			-OR-
  			2) The tile is non-flat if
  				a) the player building is an "old-school" AI
  				-OR-
  				b) the build_on_slopes switch is disabled
  		*/
  		if (IsSteepTileh(tileh) ||
  				((_is_old_ai_player || !_patches.build_on_slopes) && tileh != 0)) {
  			_error_message = STR_0007_FLAT_LAND_REQUIRED;
  			return CMD_ERROR;
  		}
  
  		flat_z = z;
  		if (tileh) {
  			// need to check so the entrance to the station is not pointing at a slope.
  			if ((invalid_dirs&1 && !(tileh & 0xC) && (uint)w_cur == w) ||
  					(invalid_dirs&2 && !(tileh & 6) &&	h_cur == 1) ||
  					(invalid_dirs&4 && !(tileh & 3) && w_cur == 1) ||
  					(invalid_dirs&8 && !(tileh & 9) && (uint)h_cur == h)) {
  				_error_message = STR_0007_FLAT_LAND_REQUIRED;
  				return CMD_ERROR;
  			}
  			cost += _price.terraform;
  			flat_z += 8;
  		}
  
  		// get corresponding flat level and make sure that all parts of the station have the same level.
  		if (allowed_z == -1) {
  			// first tile
  			allowed_z = flat_z;
  		} else if (allowed_z != flat_z) {
  			_error_message = STR_0007_FLAT_LAND_REQUIRED;
  			return CMD_ERROR;
  		}
  
  		// if station is set, then we have special handling to allow building on top of already existing stations.
  		// so station points to INVALID_STATION if we can build on any station. or it points to a station if we're only allowed to build
  		// on exactly that station.
  		if (station != NULL && IsTileType(tile_cur, MP_STATION)) {
  			if (_m[tile_cur].m5 >= 8) {
  				_error_message = ClearTile_Station(tile_cur, DC_AUTO); // get error message
  				return CMD_ERROR;
  			} else {
  				StationID st = _m[tile_cur].m2;
  				if (*station == INVALID_STATION) {
  					*station = st;
  				} else if (*station != st) {
  					_error_message = STR_3006_ADJOINS_MORE_THAN_ONE_EXISTING;
  					return CMD_ERROR;
  				}
  			}
  		} else {
  			ret = DoCommandByTile(tile_cur, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
  			if (CmdFailed(ret)) return CMD_ERROR;
  			cost += ret;
  		}
  	END_TILE_LOOP(tile_cur, w, h, tile)
  
  	return cost;
  }
  
  static bool CanExpandRailroadStation(Station *st, uint *fin, int direction)
  {
  	uint curw = st->trainst_w, curh = st->trainst_h;
  	TileIndex tile = fin[0];
  	uint w = fin[1];
  	uint h = fin[2];
  
  	if (_patches.nonuniform_stations) {
  		// determine new size of train station region..
  		int x = min(TileX(st->train_tile), TileX(tile));
  		int y = min(TileY(st->train_tile), TileY(tile));
  		curw = max(TileX(st->train_tile) + curw, TileX(tile) + w) - x;
  		curh = max(TileY(st->train_tile) + curh, TileY(tile) + h) - y;
  		tile = TileXY(x, y);
  	} else {
  		// check so the direction is the same
  		if ((_m[st->train_tile].m5 & 1) != direction) {
  			_error_message = STR_306D_NONUNIFORM_STATIONS_DISALLOWED;
  			return false;
  		}
  
  		// check if the new station adjoins the old station in either direction
  		if (curw == w && st->train_tile == tile + TileDiffXY(0, h)) {
  			// above
  			curh += h;
  		} else if (curw == w && st->train_tile == tile - TileDiffXY(0, curh)) {
  			// below
  			tile -= TileDiffXY(0, curh);
  			curh += h;
  		} else if (curh == h && st->train_tile == tile + TileDiffXY(w, 0)) {
  			// to the left
  			curw += w;
  		} else if (curh == h && st->train_tile == tile - TileDiffXY(curw, 0)) {
  			// to the right
  			tile -= TileDiffXY(curw, 0);
  			curw += w;
  		} else {
  			_error_message = STR_306D_NONUNIFORM_STATIONS_DISALLOWED;
  			return false;
  		}
  	}
  	// make sure the final size is not too big.
  	if (curw > _patches.station_spread || curh > _patches.station_spread) {
  		_error_message = STR_306C_STATION_TOO_SPREAD_OUT;
  		return false;
  	}
  
  	// now tile contains the new value for st->train_tile
  	// curw, curh contain the new value for width and height
  	fin[0] = tile;
  	fin[1] = curw;
  	fin[2] = curh;
  	return true;
  }
  
  static inline byte *CreateSingle(byte *layout, int n)
  {
  	int i = n;
  	do *layout++ = 0; while (--i);
  	layout[((n-1) >> 1)-n] = 2;
  	return layout;
  }
  
  static inline byte *CreateMulti(byte *layout, int n, byte b)
  {
  	int i = n;
  	do *layout++ = b; while (--i);
  	if (n > 4) {
  		layout[0-n] = 0;
  		layout[n-1-n] = 0;
  	}
  	return layout;
  }
  
  static void GetStationLayout(byte *layout, int numtracks, int plat_len, const StationSpec *spec)
  {
  	if (spec != NULL && spec->lengths >= plat_len &&
  			spec->platforms[plat_len - 1] >= numtracks &&
  			spec->layouts[plat_len - 1][numtracks - 1]) {
  		/* Custom layout defined, follow it. */
  		memcpy(layout, spec->layouts[plat_len - 1][numtracks - 1],
  			plat_len * numtracks);
  		return;
  	}
  
  	if (plat_len == 1) {
  		CreateSingle(layout, numtracks);
  	} else {
  		if (numtracks & 1) layout = CreateSingle(layout, plat_len);
  		numtracks >>= 1;
  
  		while (--numtracks >= 0) {
  			layout = CreateMulti(layout, plat_len, 4);
  			layout = CreateMulti(layout, plat_len, 6);
  		}
  	}
  }
  
  /** Build railroad station
   * @param x,y starting position of station dragging/placement
   * @param p1 various bitstuffed elements
   * - p1 = (bit  0)    - orientation (p1 & 1)
   * - p1 = (bit  8-15) - number of tracks
   * - p1 = (bit 16-23) - platform length
   * @param p2 various bitstuffed elements
   * - p2 = (bit  0- 3) - railtype (p2 & 0xF)
   * - p2 = (bit  4)    - set for custom station (p2 & 0x10)
   * - p2 = (bit  8-..) - custom station id (p2 >> 8)
   */
  int32 CmdBuildRailroadStation(int x, int y, uint32 flags, uint32 p1, uint32 p2)
  {
  	Station *st;
  	TileIndex tile_org;
  	int w_org, h_org;
  	int32 cost, ret;
  	StationID est;
  	int plat_len, numtracks;
  	int direction;
  	uint finalvalues[3];
  
  	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
  
  	tile_org = TileVirtXY(x, y);
  
  	/* Does the authority allow this? */
  	if (!(flags & DC_NO_TOWN_RATING) && !CheckIfAuthorityAllows(tile_org)) return CMD_ERROR;
  	if (!ValParamRailtype(p2 & 0xF)) return CMD_ERROR;
  
  	/* unpack parameters */
  	direction = p1 & 1;
  	numtracks = GB(p1,  8, 8);
  	plat_len  = GB(p1, 16, 8);
  	/* w = length, h = num_tracks */
  	if (direction) {
  		h_org = plat_len;
  		w_org = numtracks;
  	} else {
  		w_org = plat_len;
  		h_org = numtracks;
  	}
  
  	if (h_org > _patches.station_spread || w_org > _patches.station_spread) return CMD_ERROR;
  
  	// these values are those that will be stored in train_tile and station_platforms
  	finalvalues[0] = tile_org;
  	finalvalues[1] = w_org;
  	finalvalues[2] = h_org;
  
  	// Make sure the area below consists of clear tiles. (OR tiles belonging to a certain rail station)
  	est = INVALID_STATION;
  	// If DC_EXEC is in flag, do not want to pass it to CheckFlatLandBelow, because of a nice bug
  	//  for detail info, see: https://sourceforge.net/tracker/index.php?func=detail&aid=1029064&group_id=103924&atid=636365
  	if (CmdFailed(ret = CheckFlatLandBelow(tile_org, w_org, h_org, flags&~DC_EXEC, 5 << direction, _patches.nonuniform_stations ? &est : NULL))) return CMD_ERROR;
  	cost = ret + (numtracks * _price.train_station_track + _price.train_station_length) * plat_len;
  
  	// Make sure there are no similar stations around us.
  	st = GetStationAround(tile_org, w_org, h_org, est);
  	if (st == CHECK_STATIONS_ERR) return CMD_ERROR;
  
  	// See if there is a deleted station close to us.
  	if (st == NULL) {
  		st = GetClosestStationFromTile(tile_org, 8, _current_player);
  		if (st != NULL && st->facilities) st = NULL;
  	}
  
  	if (st != NULL) {
  		// Reuse an existing station.
  		if (st->owner != OWNER_NONE && st->owner != _current_player)
  			return_cmd_error(STR_3009_TOO_CLOSE_TO_ANOTHER_STATION);
  
  		if (st->train_tile != 0) {
  			// check if we want to expanding an already existing station?
  			if (_is_old_ai_player || !_patches.join_stations)
  				return_cmd_error(STR_3005_TOO_CLOSE_TO_ANOTHER_RAILROAD);
  			if (!CanExpandRailroadStation(st, finalvalues, direction))
  				return CMD_ERROR;
  		}
  
  		//XXX can't we pack this in the "else" part of the if above?
  		if (!CheckStationSpreadOut(st, tile_org, w_org, h_org)) return CMD_ERROR;
  	}	else {
  		// Create a new station
  		st = AllocateStation();
  		if (st == NULL) return CMD_ERROR;
  
  		st->town = ClosestTownFromTile(tile_org, (uint)-1);
  		if (_current_player < MAX_PLAYERS && flags & DC_EXEC)
  			SETBIT(st->town->have_ratings, _current_player);
  
  		if (!GenerateStationName(st, tile_org, 0)) return CMD_ERROR;
  
  		if (flags & DC_EXEC) StationInitialize(st, tile_org);
  	}
  
  	if (flags & DC_EXEC) {
  		TileIndexDiff tile_delta;
  		byte *layout_ptr;
  		StationID station_index = st->index;
  		const StationSpec *statspec;
  
  		// Now really clear the land below the station
  		// It should never return CMD_ERROR.. but you never know ;)
  		//  (a bit strange function name for it, but it really does clear the land, when DC_EXEC is in flags)
  		if (CmdFailed(CheckFlatLandBelow(tile_org, w_org, h_org, flags, 5 << direction, _patches.nonuniform_stations ? &est : NULL))) return CMD_ERROR;
  
  		st->train_tile = finalvalues[0];
  		if (!st->facilities) st->xy = finalvalues[0];
  		st->facilities |= FACIL_TRAIN;
  		st->owner = _current_player;
  
  		st->trainst_w = finalvalues[1];
  		st->trainst_h = finalvalues[2];
  
  		st->build_date = _date;
  
  		tile_delta = direction ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
  
  		statspec = (p2 & 0x10) != 0 ? GetCustomStation(STAT_CLASS_DFLT, p2 >> 8) : NULL;
  		layout_ptr = alloca(numtracks * plat_len);
  		GetStationLayout(layout_ptr, numtracks, plat_len, statspec);
  
  		do {
  			TileIndex tile = tile_org;
  			int w = plat_len;
  			do {
  
  				ModifyTile(tile,
  					MP_SETTYPE(MP_STATION) | MP_MAPOWNER_CURRENT |
  					MP_MAP2 | MP_MAP5 | MP_MAP3LO | MP_MAP3HI,
  					station_index, /* map2 parameter */
  					p2 & 0xFF,     /* map3lo parameter */
  					p2 >> 8,       /* map3hi parameter */
  					(*layout_ptr++) + direction   /* map5 parameter */
  				);
  
  				tile += tile_delta;
  			} while (--w);
  			tile_org += tile_delta ^ TileDiffXY(1, 1); // perpendicular to tile_delta
  		} while (--numtracks);
  
  		UpdateStationVirtCoordDirty(st);
  		UpdateStationAcceptance(st, false);
  		InvalidateWindow(WC_STATION_LIST, st->owner);
  	}
  
  	return cost;
  }
  
  static void MakeRailwayStationAreaSmaller(Station *st)
  {
  	uint w = st->trainst_w;
  	uint h = st->trainst_h;
  	TileIndex tile = st->train_tile;
  	uint i;
  
  restart:
  
  	// too small?
  	if (w != 0 && h != 0) {
  		// check the left side, x = constant, y changes
  		for (i = 0; !TileBelongsToRailStation(st, tile + TileDiffXY(0, i));) {
  			// the left side is unused?
  			if (++i == h) {
  				tile += TileDiffXY(1, 0);
  				w--;
  				goto restart;
  			}
  		}
  
  		// check the right side, x = constant, y changes
  		for (i = 0; !TileBelongsToRailStation(st, tile + TileDiffXY(w - 1, i));) {
  			// the right side is unused?
  			if (++i == h) {
  				w--;
  				goto restart;
  			}
  		}
  
  		// check the upper side, y = constant, x changes
  		for (i = 0; !TileBelongsToRailStation(st, tile + TileDiffXY(i, 0));) {
  			// the left side is unused?
  			if (++i == w) {
  				tile += TileDiffXY(0, 1);
  				h--;
  				goto restart;
  			}
  		}
  
  		// check the lower side, y = constant, x changes
  		for (i = 0; !TileBelongsToRailStation(st, tile + TileDiffXY(i, h - 1));) {
  			// the left side is unused?
  			if (++i == w) {
  				h--;
  				goto restart;
  			}
  		}
  	} else {
  		tile = 0;
  	}
  
  	st->trainst_w = w;
  	st->trainst_h = h;
  	st->train_tile = tile;
  }
  
  /** Remove a single tile from a railroad station.
   * This allows for custom-built station with holes and weird layouts
   * @param x,y tile coordinates to remove
   * @param p1 unused
   * @param p2 unused
   */
  int32 CmdRemoveFromRailroadStation(int x, int y, uint32 flags, uint32 p1, uint32 p2)
  {
  	TileIndex tile = TileVirtXY(x, y);
  	Station *st;
  
  	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
  
  	// make sure the specified tile belongs to the current player, and that it is a railroad station.
  	if (!IsTileType(tile, MP_STATION) || _m[tile].m5 >= 8 || !_patches.nonuniform_stations) return CMD_ERROR;
  	st = GetStation(_m[tile].m2);
  	if (_current_player != OWNER_WATER && (!CheckOwnership(st->owner) || !EnsureNoVehicle(tile))) return CMD_ERROR;
  
  	// if we reached here, it means we can actually delete it. do that.
  	if (flags & DC_EXEC) {
  		DoClearSquare(tile);
  		// now we need to make the "spanned" area of the railway station smaller if we deleted something at the edges.
  		// we also need to adjust train_tile.
  		MakeRailwayStationAreaSmaller(st);
  
  		// if we deleted the whole station, delete the train facility.
  		if (st->train_tile == 0) {
  			st->facilities &= ~FACIL_TRAIN;
  			UpdateStationVirtCoordDirty(st);
  			DeleteStationIfEmpty(st);
  		}
  	}
  	return _price.remove_rail_station;
  }
  
  // determine the number of platforms for the station
  uint GetStationPlatforms(const Station *st, TileIndex tile)
  {
  	TileIndex t;
  	TileIndexDiff delta;
  	int dir;
  	uint len;
  	assert(TileBelongsToRailStation(st, tile));
  
  	len = 0;
  	dir = _m[tile].m5 & 1;
  	delta = dir ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
  
  	// find starting tile..
  	t = tile;
  	do {
  		t -= delta;
  		len++;
  	} while (TileBelongsToRailStation(st, t) && (_m[t].m5 & 1) == dir);
  
  	// find ending tile
  	t = tile;
  	do {
  		t += delta;
  		len++;
  	} while (TileBelongsToRailStation(st, t) && (_m[t].m5 & 1) == dir);
  
  	return len - 1;
  }
  
  static const RealSpriteGroup *ResolveStationSpriteGroup(const SpriteGroup *spg, const Station *st)
  {
  	switch (spg->type) {
  		case SGT_REAL:
  			return &spg->g.real;
  
  		case SGT_DETERMINISTIC: {
  			const DeterministicSpriteGroup *dsg = &spg->g.determ;
  			SpriteGroup *target;
  			int value = -1;
  
  			if ((dsg->variable >> 6) == 0) {
  				/* General property */
  				value = GetDeterministicSpriteValue(dsg->variable);
  
  			} else {
  				if (st == NULL) {
  					/* We are in a build dialog of something,
  					 * and we are checking for something undefined.
  					 * That means we should get the first target
  					 * (NOT the default one). */
  					if (dsg->num_ranges > 0) {
  						target = dsg->ranges[0].group;
  					} else {
  						target = dsg->default_group;
  					}
  					return ResolveStationSpriteGroup(target, NULL);
  				}
  
  				/* Station-specific property. */
  				if (dsg->var_scope == VSG_SCOPE_PARENT) {
  					/* TODO: Town structure. */
  
  				} else /* VSG_SELF */ {
  					if (dsg->variable == 0x40 || dsg->variable == 0x41) {
  						/* FIXME: This is ad hoc only
  						 * for waypoints. */
  						value = 0x01010000;
  					} else {
  						/* TODO: Only small fraction done. */
  						// TTDPatch runs on little-endian arch;
  						// Variable is 0x70 + offset in the TTD's station structure
  						switch (dsg->variable - 0x70) {
  							case 0x80: value = st->facilities;             break;
  							case 0x81: value = st->airport_type;           break;
  							case 0x82: value = st->truck_stops->status;    break;
  							case 0x83: value = st->bus_stops->status;      break;
  							case 0x86: value = st->airport_flags & 0xFFFF; break;
  							case 0x87: value = st->airport_flags & 0xFF;   break;
  							case 0x8A: value = st->build_date;             break;
  						}
  					}
  				}
  			}
  
  			target = value != -1 ? EvalDeterministicSpriteGroup(dsg, value) : dsg->default_group;
  			return ResolveStationSpriteGroup(target, st);
  		}
  
  		default:
  		case SGT_RANDOMIZED:
  			error("I don't know how to handle random spritegroups yet!");
  			return NULL;
  	}
  }
  
  uint32 GetCustomStationRelocation(const StationSpec *spec, const Station *st, byte ctype)
  {
  	const RealSpriteGroup *rsg = ResolveStationSpriteGroup(spec->spritegroup[ctype], st);
  
  	if (rsg->sprites_per_set != 0) {
  		if (rsg->loading_count != 0) return rsg->loading[0]->g.result.result;
  
  		if (rsg->loaded_count != 0) return rsg->loaded[0]->g.result.result;
  	}
  
  	error("Custom station 0x%08x::0x%02x has no sprites associated.",
  		spec->grfid, spec->localidx);
  	/* This is what gets subscribed of dtss->image in newgrf.c,
  	 * so it's probably kinda "default offset". Try to use it as
  	 * emergency measure. */
  	return SPR_RAIL_PLATFORM_Y_FRONT;
  }
  
  static int32 RemoveRailroadStation(Station *st, TileIndex tile, uint32 flags)
  {
  	int w,h;
  	int32 cost;
  
  	/* if there is flooding and non-uniform stations are enabled, remove platforms tile by tile */
  	if (_current_player == OWNER_WATER && _patches.nonuniform_stations)
  		return DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_REMOVE_FROM_RAILROAD_STATION);
  
  	/* Current player owns the station? */
  	if (_current_player != OWNER_WATER && !CheckOwnership(st->owner))
  		return CMD_ERROR;
  
  	/* determine width and height of platforms */
  	tile = st->train_tile;
  	w = st->trainst_w;
  	h = st->trainst_h;
  
  	assert(w != 0 && h != 0);
  
  	/* cost is area * constant */
  	cost = w*h*_price.remove_rail_station;
  
  	/* clear all areas of the station */
  	do {
  		int w_bak = w;
  		do {
  			// for nonuniform stations, only remove tiles that are actually train station tiles
  			if (TileBelongsToRailStation(st, tile)) {
  				if (!EnsureNoVehicle(tile))
  					return CMD_ERROR;
  				if (flags & DC_EXEC)
  					DoClearSquare(tile);
  			}
  			tile += TileDiffXY(1, 0);
  		} while (--w);
  		w = w_bak;
  		tile += TileDiffXY(-w, 1);
  	} while (--h);
  
  	if (flags & DC_EXEC) {
  		st->train_tile = 0;
  		st->facilities &= ~FACIL_TRAIN;
  
  		UpdateStationVirtCoordDirty(st);
  		DeleteStationIfEmpty(st);
  	}
  
  	return cost;
  }
  
  int32 DoConvertStationRail(TileIndex tile, uint totype, bool exec)
  {
  	const Station *st = GetStation(_m[tile].m2);
  	if (!CheckOwnership(st->owner) || !EnsureNoVehicle(tile)) return CMD_ERROR;
  
  	// tile is not a railroad station?
  	if (_m[tile].m5 >= 8) return CMD_ERROR;
  
  	// tile is already of requested type?
  	if (GB(_m[tile].m3, 0, 4) == totype) return CMD_ERROR;
  
  	if (exec) {
  		// change type.
  		SB(_m[tile].m3, 0, 4, totype);
  		MarkTileDirtyByTile(tile);
  	}
  
  	return _price.build_rail >> 1;
  }
  
  static void FindRoadStationSpot(bool truck_station, Station* st, RoadStop*** currstop, RoadStop** prev)
  {
  	RoadStop **primary_stop;
  
  	primary_stop = (truck_station) ? &st->truck_stops : &st->bus_stops;
  
  	if (*primary_stop == NULL) {
  		//we have no station of the type yet, so write a "primary station"
  		//(the one at st->foo_stops)
  		*currstop = primary_stop;
  	} else {
  		//there are stops already, so append to the end of the list
  		*prev = *primary_stop;
  		*currstop = &(*primary_stop)->next;
  		while (**currstop != NULL) {
  			*prev = (*prev)->next;
  			*currstop = &(**currstop)->next;
  		}
  	}
  }
  
  /** Build a bus station
   * @param x,y coordinates to build bus station at
   * @param p1 busstop entrance direction (0 through 3), where 0 is NW, 1 is NE, etc.
   * @param p2 0 for Bus stops, 1 for truck stops
   */
  int32 CmdBuildRoadStop(int x, int y, uint32 flags, uint32 p1, uint32 p2)
  {
  	Station *st;
  	RoadStop *road_stop;
  	RoadStop **currstop;
  	RoadStop *prev = NULL;
  	TileIndex tile;
  	int32 cost;
  	bool type = !!p2;
  
  	/* Saveguard the parameters */
  	if (p1 > 3) return CMD_ERROR;
  
  	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
  
  	tile = TileVirtXY(x, y);
  
  	if (!(flags & DC_NO_TOWN_RATING) && !CheckIfAuthorityAllows(tile))
  		return CMD_ERROR;
  
  	cost = CheckFlatLandBelow(tile, 1, 1, flags, 1 << p1, NULL);
  	if (CmdFailed(cost)) return CMD_ERROR;
  
  	st = GetStationAround(tile, 1, 1, -1);
  	if (st == CHECK_STATIONS_ERR) return CMD_ERROR;
  
  	/* Find a station close to us */
  	if (st == NULL) {
  		st = GetClosestStationFromTile(tile, 8, _current_player);
  		if (st != NULL && st->facilities) st = NULL;
  	}
  
  	//give us a road stop in the list, and check if something went wrong
  	road_stop = AllocateRoadStop();
  	if (road_stop == NULL)
  		return_cmd_error( (type) ? STR_3008B_TOO_MANY_TRUCK_STOPS : STR_3008A_TOO_MANY_BUS_STOPS);
  
  	if ( st != NULL && (GetNumRoadStops(st, RS_BUS) + GetNumRoadStops(st, RS_TRUCK) >= ROAD_STOP_LIMIT))
  		return_cmd_error( (type) ? STR_3008B_TOO_MANY_TRUCK_STOPS : STR_3008A_TOO_MANY_BUS_STOPS);
  
  	if (st != NULL) {
  		if (st->owner != OWNER_NONE && st->owner != _current_player)
  			return_cmd_error(STR_3009_TOO_CLOSE_TO_ANOTHER_STATION);
  
  		if (!CheckStationSpreadOut(st, tile, 1, 1))
  			return CMD_ERROR;
  
  		FindRoadStationSpot(type, st, &currstop, &prev);
  	} else {
  		Town *t;
  
  		st = AllocateStation();
  		if (st == NULL) return CMD_ERROR;
  
  		st->town = t = ClosestTownFromTile(tile, (uint)-1);
  
  		FindRoadStationSpot(type, st, &currstop, &prev);
  
  		if (_current_player < MAX_PLAYERS && flags&DC_EXEC)
  			SETBIT(t->have_ratings, _current_player);
  
  		st->sign.width_1 = 0;
  
  		if (!GenerateStationName(st, tile, 0)) return CMD_ERROR;
  
  		if (flags & DC_EXEC) StationInitialize(st, tile);
  	}
  
  	cost += (type) ? _price.build_truck_station : _price.build_bus_station;
  
  	if (flags & DC_EXEC) {
  		//point to the correct item in the _busstops or _truckstops array
  		*currstop = road_stop;
  
  		//initialize an empty station
  		InitializeRoadStop(road_stop, prev, tile, st->index);
  		(*currstop)->type = type;
  		if (!st->facilities) st->xy = tile;
  		st->facilities |= (type) ? FACIL_TRUCK_STOP : FACIL_BUS_STOP;
  		st->owner = _current_player;
  
  		st->build_date = _date;
  
  		ModifyTile(tile,
  			MP_SETTYPE(MP_STATION) | MP_MAPOWNER_CURRENT |
  			MP_MAP2 | MP_MAP5 | MP_MAP3LO_CLEAR | MP_MAP3HI_CLEAR,
  			st->index,                       /* map2 parameter */
  			/* XXX - Truck stops have 0x43 _m[].m5 value + direction
  			 * XXX - Bus stops have a _map5 value of 0x47 + direction */
  			((type) ? 0x43 : 0x47) + p1 /* map5 parameter */
  		);
  
  		UpdateStationVirtCoordDirty(st);
  		UpdateStationAcceptance(st, false);
  		InvalidateWindow(WC_STATION_LIST, st->owner);
  	}
  	return cost;
  }
  
  // Remove a bus station
  static int32 RemoveRoadStop(Station *st, uint32 flags, TileIndex tile)
  {
  	RoadStop **primary_stop;
  	RoadStop *cur_stop;
  	bool is_truck = _m[tile].m5 < 0x47;
  
  	if (_current_player != OWNER_WATER && !CheckOwnership(st->owner))
  		return CMD_ERROR;
  
  	if (is_truck) { // truck stop
  		primary_stop = &st->truck_stops;
  		cur_stop = GetRoadStopByTile(tile, RS_TRUCK);
  	} else {
  		primary_stop = &st->bus_stops;
  		cur_stop = GetRoadStopByTile(tile, RS_BUS);
  	}
  
  	assert(cur_stop != NULL);
  
  	if (!EnsureNoVehicle(tile))
  		return CMD_ERROR;
  
  	if (flags & DC_EXEC) {
  		uint i;
  		DoClearSquare(tile);
  
  		/* Clear all vehicles destined for this station */
  		for (i = 0; i != NUM_SLOTS; i++) {
  			if (cur_stop->slot[i] != INVALID_SLOT) {
  				Vehicle *v = GetVehicle(cur_stop->slot[i]);
  				ClearSlot(v, v->u.road.slot);
  			}
  		}
  
  		cur_stop->used = false;
  		if (cur_stop->prev != NULL) cur_stop->prev->next = cur_stop->next;
  		if (cur_stop->next != NULL) cur_stop->next->prev = cur_stop->prev;
  
  		//we only had one stop left
  		if (cur_stop->next == NULL && cur_stop->prev == NULL) {
  			//so we remove ALL stops
  			*primary_stop = NULL;
  			st->facilities &= (is_truck) ? ~FACIL_TRUCK_STOP : ~FACIL_BUS_STOP;
  		} else if (cur_stop == *primary_stop) {
  			//removed the first stop in the list
  			//need to set the primary element to the next stop
  			*primary_stop = (*primary_stop)->next;
  		}
  
  		UpdateStationVirtCoordDirty(st);
  		DeleteStationIfEmpty(st);
  	}
  
  	return (is_truck) ? _price.remove_truck_station : _price.remove_bus_station;
  }
  
  
  
  // FIXME -- need to move to its corresponding Airport variable
  // Country Airfield (small)
  static const byte _airport_map5_tiles_country[] = {
  	54, 53, 52, 65,
  	58, 57, 56, 55,
  	64, 63, 63, 62
  };
  
  // City Airport (large)
  static const byte _airport_map5_tiles_town[] = {
  	31,  9, 33,  9,  9, 32,
  	27, 36, 29, 34,  8, 10,
  	30, 11, 35, 13, 20, 21,
  	51, 12, 14, 17, 19, 28,
  	38, 13, 15, 16, 18, 39,
  	26, 22, 23, 24, 25, 26
  };
  
  // Metropolitain Airport (large) - 2 runways
  static const byte _airport_map5_tiles_metropolitan[] = {
  	 31,  9, 33,  9,  9, 32,
  	 27, 36, 29, 34,  8, 10,
  	 30, 11, 35, 13, 20, 21,
  	102,  8,  8,  8,  8, 28,
  	 83, 84, 84, 84, 84, 83,
  	 26, 23, 23, 23, 23, 26
  };
  
  // International Airport (large) - 2 runways
  static const byte _airport_map5_tiles_international[] = {
    88, 89, 89, 89, 89, 89,  88,
   	51,  8,  8,  8,  8,  8,  32,
  	30,  8, 11, 27, 11,  8,  10,
  	32,  8, 11, 27, 11,  8, 114,
  	87,  8, 11, 85, 11,  8, 114,
  	87,  8,  8,  8,  8,  8,  90,
  	26, 23, 23, 23, 23, 23,  26
  };
  
  // Heliport
  static const byte _airport_map5_tiles_heliport[] = {
  	66,
  };
  
  static const byte * const _airport_map5_tiles[] = {
  	_airport_map5_tiles_country,				// Country Airfield (small)
  	_airport_map5_tiles_town,						// City Airport (large)
  	_airport_map5_tiles_heliport,				// Heliport
  	_airport_map5_tiles_metropolitan,   // Metropolitain Airport (large)
  	_airport_map5_tiles_international,	// International Airport (xlarge)
  };
  
  /** Place an Airport.
   * @param x,y tile coordinates where airport will be built
   * @param p1 airport type, @see airport.h
   * @param p2 unused
   */
  int32 CmdBuildAirport(int x, int y, uint32 flags, uint32 p1, uint32 p2)
  {
  	TileIndex tile;
  	Town *t;
  	Station *st;
  	int32 cost;
  	int w, h;
  	bool airport_upgrade = true;
  
  	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
  
  	/* Check if a valid, buildable airport was chosen for construction */
  	if (p1 > lengthof(_airport_map5_tiles) || !HASBIT(GetValidAirports(), p1)) return CMD_ERROR;
  
  	tile = TileVirtXY(x, y);
  
  	if (!(flags & DC_NO_TOWN_RATING) && !CheckIfAuthorityAllows(tile))
  		return CMD_ERROR;
  
  	t = ClosestTownFromTile(tile, (uint)-1);
  
  	/* Check if local auth refuses a new airport */
  	{
  		uint num = 0;
  		FOR_ALL_STATIONS(st) {
  			if (st->owner != OWNER_TOWN && st->xy != 0 && st->town == t && st->facilities&FACIL_AIRPORT && st->airport_type != AT_OILRIG)
  				num++;
  		}
  		if (num >= 2 && _current_player != OWNER_TOWN) {
  			SetDParam(0, t->index);
  			return_cmd_error(STR_2035_LOCAL_AUTHORITY_REFUSES);
  		}
  	}
  
  	w = _airport_size_x[p1];
  	h = _airport_size_y[p1];
  
  	cost = CheckFlatLandBelow(tile, w, h, flags, 0, NULL);
  	if (CmdFailed(cost)) return CMD_ERROR;
  
  	st = GetStationAround(tile, w, h, -1);
  	if (st == CHECK_STATIONS_ERR) return CMD_ERROR;
  
  	/* Find a station close to us */
  	if (st == NULL) {
  		st = GetClosestStationFromTile(tile, 8, _current_player);
  		if (st != NULL && st->facilities) st = NULL;
  	}
  
  	if (st != NULL) {
  		if (st->owner != OWNER_NONE && st->owner != _current_player)
  			return_cmd_error(STR_3009_TOO_CLOSE_TO_ANOTHER_STATION);
  
  		if (!CheckStationSpreadOut(st, tile, 1, 1))
  			return CMD_ERROR;
  
  		if (st->airport_tile != 0)
  			return_cmd_error(STR_300D_TOO_CLOSE_TO_ANOTHER_AIRPORT);
  	} else {
  		airport_upgrade = false;
  
  		st = AllocateStation();
  		if (st == NULL) return CMD_ERROR;
  
  		st->town = t;
  
  		if (_current_player < MAX_PLAYERS && flags & DC_EXEC)
  			SETBIT(t->have_ratings, _current_player);
  
  		st->sign.width_1 = 0;
  
  		// if airport type equals Heliport then generate
  		// type 5 name, which is heliport, otherwise airport names (1)
  		if (!GenerateStationName(st, tile, (p1 == AT_HELIPORT) ? 5 : 1))
  			return CMD_ERROR;
  
  		if (flags & DC_EXEC)
  			StationInitialize(st, tile);
  	}
  
  	cost += _price.build_airport * w * h;
  
  	if (flags & DC_EXEC) {
  		const AirportFTAClass *afc = GetAirport(p1);
  
  		st->owner = _current_player;
  		if (IsLocalPlayer() && afc->nof_depots != 0)
  			_last_built_aircraft_depot_tile = tile + ToTileIndexDiff(afc->airport_depots[0]);
  
  		st->airport_tile = tile;
  		if (!st->facilities) st->xy = tile;
  		st->facilities |= FACIL_AIRPORT;
  		st->airport_type = (byte)p1;
  		st->airport_flags = 0;
  
  		st->build_date = _date;
  
  		/* if airport was demolished while planes were en-route to it, the
  		 * positions can no longer be the same (v->u.air.pos), since different
  		 * airports have different indexes. So update all planes en-route to this
  		 * airport. Only update if
  		 * 1. airport is upgraded
  		 * 2. airport is added to existing station (unfortunately unavoideable)
  		 */
  		if (airport_upgrade) UpdateAirplanesOnNewStation(st);
  
  		{
  			const byte *b = _airport_map5_tiles[p1];
  
  			BEGIN_TILE_LOOP(tile_cur,w,h,tile) {
  				ModifyTile(tile_cur,
  					MP_SETTYPE(MP_STATION) | MP_MAPOWNER_CURRENT |
  					MP_MAP2 | MP_MAP3LO_CLEAR | MP_MAP3HI_CLEAR | MP_MAP5,
  					st->index, *b++);
  			} END_TILE_LOOP(tile_cur,w,h,tile)
  		}
  
  		UpdateStationVirtCoordDirty(st);
  		UpdateStationAcceptance(st, false);
  		InvalidateWindow(WC_STATION_LIST, st->owner);
  	}
  
  	st->airport_queue = new_VQueue();
  	st->helicopter_queue = new_VQueue();
  
  	return cost;
  }
  
  static int32 RemoveAirport(Station *st, uint32 flags)
  {
  	TileIndex tile;
  	int w,h;
  	int32 cost;
  
  	if (_current_player != OWNER_WATER && !CheckOwnership(st->owner))
  		return CMD_ERROR;
  
  	tile = st->airport_tile;
  
  	w = _airport_size_x[st->airport_type];
  	h = _airport_size_y[st->airport_type];
  
  	cost = w * h * _price.remove_airport;
  
  	{
  BEGIN_TILE_LOOP(tile_cur,w,h,tile)
  		if (!EnsureNoVehicle(tile_cur))
  			return CMD_ERROR;
  
  		if (flags & DC_EXEC) {
  			DeleteAnimatedTile(tile_cur);
  			DoClearSquare(tile_cur);
  		}
  END_TILE_LOOP(tile_cur, w,h,tile)
  	}
  
  	if (flags & DC_EXEC) {
  		const AirportFTAClass *afc = GetAirport(st->airport_type);
  		uint i;
  
  		for (i = 0; i < afc->nof_depots; ++i)
  			DeleteWindowById(WC_VEHICLE_DEPOT, tile + ToTileIndexDiff(afc->airport_depots[i]));
  
  		st->airport_tile = 0;
  		st->facilities &= ~FACIL_AIRPORT;
  
  		UpdateStationVirtCoordDirty(st);
  		DeleteStationIfEmpty(st);
  	}
  
  	return cost;
  }
  
  /** Build a buoy.
   * @param x,y tile coordinates of bouy construction
   * @param p1 unused
   * @param p2 unused
   */
  int32 CmdBuildBuoy(int x, int y, uint32 flags, uint32 p1, uint32 p2)
  {
  	TileInfo ti;
  	Station *st;
  
  	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
  
  	FindLandscapeHeight(&ti, x, y);
  
  	if (ti.type != MP_WATER || ti.tileh != 0 || ti.map5 != 0 || ti.tile == 0)
  		return_cmd_error(STR_304B_SITE_UNSUITABLE);
  
  	st = AllocateStation();
  	if (st == NULL) return CMD_ERROR;
  
  	st->town = ClosestTownFromTile(ti.tile, (uint)-1);
  	st->sign.width_1 = 0;
  
  	if (!GenerateStationName(st, ti.tile, 4)) return CMD_ERROR;
  
  	if (flags & DC_EXEC) {
  		StationInitialize(st, ti.tile);
  		st->dock_tile = ti.tile;
  		st->facilities |= FACIL_DOCK;
  		/* Buoys are marked in the Station struct by this flag. Yes, it is this
  		 * braindead.. */
  		st->had_vehicle_of_type |= HVOT_BUOY;
  		st->owner = OWNER_NONE;
  
  		st->build_date = _date;
  
  		ModifyTile(ti.tile,
  			MP_SETTYPE(MP_STATION) |
  			MP_MAP2 | MP_MAP3LO_CLEAR | MP_MAP3HI_CLEAR | MP_MAPOWNER | MP_MAP5,
  			st->index,		/* map2 */
  			OWNER_NONE,		/* map_owner */
  			0x52					/* map5 */
  		);
  
  		UpdateStationVirtCoordDirty(st);
  
  		UpdateStationAcceptance(st, false);
  		InvalidateWindow(WC_STATION_LIST, st->owner);
  	}
  
  	return _price.build_dock;
  }
  
  /* Checks if any ship is servicing the buoy specified. Returns yes or no */
  static bool CheckShipsOnBuoy(Station *st)
  {
  	const Vehicle *v;
  	FOR_ALL_VEHICLES(v) {
  		if (v->type == VEH_Ship) {
  			const Order *order;
  			FOR_VEHICLE_ORDERS(v, order) {
  				if (order->type == OT_GOTO_STATION && order->station == st->index) {
  					return true;
  				}
  			}
  		}
  	}
  	return false;
  }
  
  static int32 RemoveBuoy(Station *st, uint32 flags)
  {
  	TileIndex tile;
  
  	if (_current_player >= MAX_PLAYERS) {
  		/* XXX: strange stuff */
  		return_cmd_error(INVALID_STRING_ID);
  	}
  
  	tile = st->dock_tile;
  
  	if (CheckShipsOnBuoy(st))   return_cmd_error(STR_BUOY_IS_IN_USE);
  	if (!EnsureNoVehicle(tile)) return CMD_ERROR;
  
  	if (flags & DC_EXEC) {
  		st->dock_tile = 0;
  		/* Buoys are marked in the Station struct by this flag. Yes, it is this
  		 * braindead.. */
  		st->facilities &= ~FACIL_DOCK;
  		st->had_vehicle_of_type &= ~HVOT_BUOY;
  
  		ModifyTile(tile,
  			MP_SETTYPE(MP_WATER) |
  			MP_MAP2_CLEAR | MP_MAP3LO_CLEAR | MP_MAP3HI_CLEAR | MP_MAPOWNER | MP_MAP5 | MP_MAP2_CLEAR,
  			OWNER_WATER, /* map_owner */
  			0			/* map5 */
  		);
  
  		UpdateStationVirtCoordDirty(st);
  		DeleteStationIfEmpty(st);
  	}
  
  	return _price.remove_truck_station;
  }
  
  static const TileIndexDiffC _dock_tileoffs_chkaround[] = {
  	{-1,  0},
  	{ 0,  0},
  	{ 0,  0},
  	{ 0, -1}
  };
  static const byte _dock_w_chk[4] = { 2,1,2,1 };
  static const byte _dock_h_chk[4] = { 1,2,1,2 };
  
  /** Build a dock/haven.
   * @param x,y tile coordinates where dock will be built
   * @param p1 unused
   * @param p2 unused
   */
  int32 CmdBuildDock(int x, int y, uint32 flags, uint32 p1, uint32 p2)
  {
  	TileInfo ti;
  	int direction;
  	int32 cost;
  	TileIndex tile, tile_cur;
  	Station *st;
  
  	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
  
  	FindLandscapeHeight(&ti, x, y);
  
  	if ((direction=0,ti.tileh) != 3 &&
  			(direction++,ti.tileh) != 9 &&
  			(direction++,ti.tileh) != 12 &&
  			(direction++,ti.tileh) != 6)
  		return_cmd_error(STR_304B_SITE_UNSUITABLE);
  
  	if (!EnsureNoVehicle(ti.tile)) return CMD_ERROR;
  
  	cost = DoCommandByTile(ti.tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
  	if (CmdFailed(cost)) return CMD_ERROR;
  
  	tile_cur = (tile=ti.tile) + TileOffsByDir(direction);
  
  	if (!EnsureNoVehicle(tile_cur)) return CMD_ERROR;
  
  	FindLandscapeHeightByTile(&ti, tile_cur);
  	if (ti.tileh != 0 || ti.type != MP_WATER) return_cmd_error(STR_304B_SITE_UNSUITABLE);
  
  	cost = DoCommandByTile(tile_cur, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
  	if (CmdFailed(cost)) return CMD_ERROR;
  
  	tile_cur = tile_cur + TileOffsByDir(direction);
  	FindLandscapeHeightByTile(&ti, tile_cur);
  	if (ti.tileh != 0 || ti.type != MP_WATER)
  		return_cmd_error(STR_304B_SITE_UNSUITABLE);
  
  	/* middle */
  	st = GetStationAround(
  		tile + ToTileIndexDiff(_dock_tileoffs_chkaround[direction]),
  		_dock_w_chk[direction], _dock_h_chk[direction], -1);
  	if (st == CHECK_STATIONS_ERR) return CMD_ERROR;
  
  	/* Find a station close to us */
  	if (st == NULL) {
  		st = GetClosestStationFromTile(tile, 8, _current_player);
  		if (st!=NULL && st->facilities) st = NULL;
  	}
  
  	if (st != NULL) {
  		if (st->owner != OWNER_NONE && st->owner != _current_player)
  			return_cmd_error(STR_3009_TOO_CLOSE_TO_ANOTHER_STATION);
  
  		if (!CheckStationSpreadOut(st, tile, 1, 1)) return CMD_ERROR;
  
  		if (st->dock_tile != 0) return_cmd_error(STR_304C_TOO_CLOSE_TO_ANOTHER_DOCK);
  	} else {
  		Town *t;
  
  		st = AllocateStation();
  		if (st == NULL) return CMD_ERROR;
  
  		st->town = t = ClosestTownFromTile(tile, (uint)-1);
  
  		if (_current_player < MAX_PLAYERS && flags&DC_EXEC)
  			SETBIT(t->have_ratings, _current_player);
  
  		st->sign.width_1 = 0;
  
  		if (!GenerateStationName(st, tile, 3)) return CMD_ERROR;
  
  		if (flags & DC_EXEC) StationInitialize(st, tile);
  	}
  
  	if (flags & DC_EXEC) {
  		st->dock_tile = tile;
  		if (!st->facilities) st->xy = tile;
  		st->facilities |= FACIL_DOCK;
  		st->owner = _current_player;
  
  		st->build_date = _date;
  
  		ModifyTile(tile,
  			MP_SETTYPE(MP_STATION) | MP_MAPOWNER_CURRENT |
  			MP_MAP2 | MP_MAP3LO_CLEAR | MP_MAP3HI_CLEAR |
  			MP_MAP5,
  			st->index,
  			direction + 0x4C);
  
  		ModifyTile(tile + TileOffsByDir(direction),
  			MP_SETTYPE(MP_STATION) | MP_MAPOWNER_CURRENT |
  			MP_MAP2 | MP_MAP3LO_CLEAR | MP_MAP3HI_CLEAR |
  			MP_MAP5,
  			st->index,
  			(direction&1) + 0x50);
  
  		UpdateStationVirtCoordDirty(st);
  		UpdateStationAcceptance(st, false);
  		InvalidateWindow(WC_STATION_LIST, st->owner);
  	}
  	return _price.build_dock;
  }
  
  static int32 RemoveDock(Station *st, uint32 flags)
  {
  	TileIndex tile1;
  	TileIndex tile2;
  
  	if (!CheckOwnership(st->owner)) return CMD_ERROR;
  
  	tile1 = st->dock_tile;
  	tile2 = tile1 + TileOffsByDir(_m[tile1].m5 - 0x4C);
  
  	if (!EnsureNoVehicle(tile1)) return CMD_ERROR;
  	if (!EnsureNoVehicle(tile2)) return CMD_ERROR;
  
  	if (flags & DC_EXEC) {
  		DoClearSquare(tile1);
  
  		// convert the water tile to water.
  		ModifyTile(tile2, MP_SETTYPE(MP_WATER) | MP_MAPOWNER | MP_MAP5 | MP_MAP2_CLEAR | MP_MAP3LO_CLEAR | MP_MAP3HI_CLEAR, OWNER_WATER, 0);
  
  		st->dock_tile = 0;
  		st->facilities &= ~FACIL_DOCK;
  
  		UpdateStationVirtCoordDirty(st);
  		DeleteStationIfEmpty(st);
  	}
  
  	return _price.remove_dock;
  }
  
  #include "table/station_land.h"
  
  
  extern uint16 _custom_sprites_base;
  
  static void DrawTile_Station(TileInfo *ti)
  {
  	uint32 image_or_modificator;
  	uint32 image;
  	const DrawTileSeqStruct *dtss;
  	const DrawTileSprites *t = NULL;
  	RailType railtype = GB(_m[ti->tile].m3, 0, 4);
  	const RailtypeInfo *rti = GetRailTypeInfo(railtype);
  	SpriteID offset;
  	uint32 relocation = 0;
  
  	{
  		PlayerID owner = GetTileOwner(ti->tile);
  		image_or_modificator = PALETTE_TO_GREY; /* NOTE: possible bug in ttd here? */
  		if (owner < MAX_PLAYERS) image_or_modificator = PLAYER_SPRITE_COLOR(owner);
  	}
  
  	// don't show foundation for docks (docks are between 76 (0x4C) and 81 (0x51))
  	if (ti->tileh != 0 && (ti->map5 < 0x4C || ti->map5 > 0x51))
  		DrawFoundation(ti, ti->tileh);
  
  	if (_m[ti->tile].m3 & 0x10) {
  		// look for customization
  		const StationSpec *statspec = GetCustomStation(STAT_CLASS_DFLT, _m[ti->tile].m4);
  
  		//debug("Cust-o-mized %p", statspec);
  
  		if (statspec != NULL) {
  			const Station* st = GetStation(_m[ti->tile].m2);
  
  			relocation = GetCustomStationRelocation(statspec, st, 0);
  			//debug("Relocation %d", relocation);
  			t = &statspec->renderdata[ti->map5];
  		}
  	}
  
  	if (t == NULL) t = &_station_display_datas[ti->map5];
  
  	image = t->ground_sprite;
  	if (image & PALETTE_MODIFIER_COLOR) image |= image_or_modificator;
  
  	// For custom sprites, there's no railtype-based pitching.
  	offset = (image & SPRITE_MASK) < _custom_sprites_base ? rti->total_offset : railtype;
  	image += offset;
  
  	// station_land array has been increased from 82 elements to 114
  	// but this is something else. If AI builds station with 114 it looks all weird
  	DrawGroundSprite(image);
  
  	if (_debug_pbs_level >= 1) {
  		byte pbs = PBSTileReserved(ti->tile);
  		if (pbs & TRACK_BIT_DIAG1) DrawGroundSprite(rti->base_sprites.single_y | PALETTE_CRASH);
  		if (pbs & TRACK_BIT_DIAG2) DrawGroundSprite(rti->base_sprites.single_x | PALETTE_CRASH);
  		if (pbs & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n | PALETTE_CRASH);
  		if (pbs & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s | PALETTE_CRASH);
  		if (pbs & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w | PALETTE_CRASH);
  		if (pbs & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e | PALETTE_CRASH);
  	}
  
  	foreach_draw_tile_seq(dtss, t->seq) {
  		image = dtss->image + relocation;
  		image += offset;
  		if (_display_opt & DO_TRANS_BUILDINGS) {
  			MAKE_TRANSPARENT(image);
  		} else {
  			if (image & PALETTE_MODIFIER_COLOR) image |= image_or_modificator;
  		}
  
  		if ((byte)dtss->delta_z != 0x80) {
  			AddSortableSpriteToDraw(image, ti->x + dtss->delta_x, ti->y + dtss->delta_y, dtss->width, dtss->height, dtss->unk, ti->z + dtss->delta_z);
  		} else {
  			AddChildSpriteScreen(image, dtss->delta_x, dtss->delta_y);
  		}
  	}
  }
  
  void StationPickerDrawSprite(int x, int y, RailType railtype, int image)
  {
  	uint32 ormod, img;
  	const DrawTileSeqStruct *dtss;
  	const DrawTileSprites *t;
  	const RailtypeInfo *rti = GetRailTypeInfo(railtype);
  
  	ormod = PLAYER_SPRITE_COLOR(_local_player);
  
  	t = &_station_display_datas[image];
  
  	img = t->ground_sprite;
  	if (img & PALETTE_MODIFIER_COLOR) img |= ormod;
  	DrawSprite(img + rti->total_offset, x, y);
  
  	foreach_draw_tile_seq(dtss, t->seq) {
  		Point pt = RemapCoords(dtss->delta_x, dtss->delta_y, dtss->delta_z);
  		DrawSprite((dtss->image | ormod) + rti->total_offset, x + pt.x, y + pt.y);
  	}
  }
  
  static uint GetSlopeZ_Station(const TileInfo* ti)
  {
  	return (ti->tileh != 0) ? ti->z + 8 : ti->z;
  }
  
  static uint GetSlopeTileh_Station(const TileInfo *ti)
  {
  	return 0;
  }
  
  static void GetAcceptedCargo_Station(TileIndex tile, AcceptedCargo ac)
  {
  	/* not used */
  }
  
  static void GetTileDesc_Station(TileIndex tile, TileDesc *td)
  {
  	byte m5;
  	StringID str;
  
  	td->owner = GetTileOwner(tile);
  	td->build_date = GetStation(_m[tile].m2)->build_date;
  
  	m5 = _m[tile].m5;
  	(str=STR_305E_RAILROAD_STATION, m5 < 8) ||
  	(str=STR_305F_AIRCRAFT_HANGAR, m5==32 || m5==45) || // hangars
  	(str=STR_3060_AIRPORT, m5 < 0x43 || (m5 >= 83 && m5 <= 114)) ||
  	(str=STR_3061_TRUCK_LOADING_AREA, m5 < 0x47) ||
  	(str=STR_3062_BUS_STATION, m5 < 0x4B) ||
  	(str=STR_4807_OIL_RIG, m5 == 0x4B) ||
  	(str=STR_3063_SHIP_DOCK, m5 != 0x52) ||
  	(str=STR_3069_BUOY, true);
  	td->str = str;
  }
  
  
  static uint32 GetTileTrackStatus_Station(TileIndex tile, TransportType mode)
  {
  	uint i = _m[tile].m5;
  	uint j = 0;
  
  	switch (mode) {
  		case TRANSPORT_RAIL:
  			if (i < 8) {
  				static const byte tile_track_status_rail[] = { 1, 2, 1, 2, 1, 2, 1, 2 };
  				j = tile_track_status_rail[i];
  			}
  			j += (j << 8);
  			break;
  
  		case TRANSPORT_WATER:
  			// buoy is coded as a station, it is always on open water
  			// (0x3F, all tracks available)
  			if (i == 0x52) j = 0x3F;
  			j += (j << 8);
  			break;
  
  		default:
  			break;
  	}
  
  	return j;
  }
  
  
  static void TileLoop_Station(TileIndex tile)
  {
  	// FIXME -- GetTileTrackStatus_Station -> animated stationtiles
  	// hardcoded.....not good
  	switch (_m[tile].m5) {
  		case 0x27: // large big airport
  		case 0x3A: // flag small airport
  		case 0x5A: // radar international airport
  		case 0x66: // radar metropolitan airport
  			AddAnimatedTile(tile);
  			break;
  
  		case 0x4B: // oilrig (station part)
  		case 0x52: // bouy
  			TileLoop_Water(tile);
  			break;
  
  		default: break;
  	}
  }
  
  
  static void AnimateTile_Station(TileIndex tile)
  {
  	byte m5 = _m[tile].m5;
  	//FIXME -- AnimateTile_Station -> not nice code, lots of things double
    // again hardcoded...was a quick hack
  
    // turning radar / windsack on airport
  	if (m5 >= 39 && m5 <= 50) { // turning radar (39 - 50)
  		if (_tick_counter & 3)
  			return;
  
  		if (++m5 == 50+1)
  			m5 = 39;
  
  		_m[tile].m5 = m5;
  		MarkTileDirtyByTile(tile);
    //added - begin
  	} else if (m5 >= 90 && m5 <= 113) { // turning radar with ground under it (different fences) (90 - 101 | 102 - 113)
  		if (_tick_counter & 3)
  			return;
  
  		m5++;
  
  		if (m5 == 101+1) {m5 = 90;}  // radar with fences in south
  		else if (m5 == 113+1) {m5 = 102;} // radar with fences in north
  
  		_m[tile].m5 = m5;
  		MarkTileDirtyByTile(tile);
  	//added - end
  	} else if (m5 >= 0x3A && m5 <= 0x3D) {  // windsack (58 - 61)
  		if (_tick_counter & 1)
  			return;
  
  		if (++m5 == 0x3D+1)
  			m5 = 0x3A;
  
  		_m[tile].m5 = m5;
  		MarkTileDirtyByTile(tile);
  	}
  }
  
  static void ClickTile_Station(TileIndex tile)
  {
    // 0x20 - hangar large airport (32)
    // 0x41 - hangar small airport (65)
  	if (_m[tile].m5 == 32 || _m[tile].m5 == 65) {
  		ShowAircraftDepotWindow(tile);
  	} else {
  		ShowStationViewWindow(_m[tile].m2);
  	}
  }
  
  static const byte _enter_station_speedtable[12] = {
  	215, 195, 175, 155, 135, 115, 95, 75, 55, 35, 15, 0
  };
  
  static uint32 VehicleEnter_Station(Vehicle *v, TileIndex tile, int x, int y)
  {
  	StationID station_id;
  	byte dir;
  
  	if (v->type == VEH_Train) {
  		if (IS_BYTE_INSIDE(_m[tile].m5, 0, 8) && IsFrontEngine(v) &&
  				!IsCompatibleTrainStationTile(tile + TileOffsByDir(v->direction >> 1), tile)) {
  
  			station_id = _m[tile].m2;
  			if ((!(v->current_order.flags & OF_NON_STOP) && !_patches.new_nonstop) ||
  					(v->current_order.type == OT_GOTO_STATION && v->current_order.station == station_id)) {
  				if (!(_patches.new_nonstop && v->current_order.flags & OF_NON_STOP) &&
  						v->current_order.type != OT_LEAVESTATION &&
  						v->last_station_visited != station_id) {
  					x &= 0xF;
  					y &= 0xF;
  
  					dir = v->direction & 6;
  					if (dir & 2) intswap(x,y);
  					if (y == 8) {
  						if (dir != 2 && dir != 4) x = ~x & 0xF;
  						if (x == 12) return 2 | (station_id << 8); /* enter station */
  						if (x < 12) {
  							uint16 spd;
  
  							v->vehstatus |= VS_TRAIN_SLOWING;
  							spd = _enter_station_speedtable[x];
  							if (spd < v->cur_speed) v->cur_speed = spd;
  						}
  					}
  				}
  			}
  		}
  	} else if (v->type == VEH_Road) {
  		if (v->u.road.state < 16 && !HASBIT(v->u.road.state, 2) && v->u.road.frame == 0) {
  			if (IS_BYTE_INSIDE(_m[tile].m5, 0x43, 0x4B)) {
  				/* Attempt to allocate a parking bay in a road stop */
  				RoadStop *rs = GetRoadStopByTile(tile, GetRoadStopType(tile));
  
  				/* rs->status bits 0 and 1 describe current the two parking spots.
  				 * 0 means occupied, 1 means free. */
  
  				// Check if station is busy or if there are no free bays.
  				if (HASBIT(rs->status, 7) || GB(rs->status, 0, 2) == 0)
  					return 8;
  
  				v->u.road.state += 32;
  
  				// if the first bay is free, allocate that, else the second bay must be free.
  				if (HASBIT(rs->status, 0)) {
  					CLRBIT(rs->status, 0);
  				} else {
  					CLRBIT(rs->status, 1);
  					v->u.road.state += 2;
  				}
  
  				// mark the station as busy
  				SETBIT(rs->status, 7);
  			}
  		}
  	}
  
  	return 0;
  }
  
  /** Removes a station from the list.
    * This is done by setting the .xy property to 0,
    * and doing some maintenance, especially clearing vehicle orders.
    * Aircraft-Hangar orders need special treatment here, as the hangars are
    * actually part of a station (tiletype is STATION), but the order type
    * is OT_GOTO_DEPOT.
    * @param st Station to be deleted
    */
  static void DeleteStation(Station *st)
  {
  	Order order;
  	StationID index;
  	Vehicle *v;
  	st->xy = 0;
  
  	DeleteName(st->string_id);
  	MarkStationDirty(st);
  	_global_station_sort_dirty = true; // delete station, remove sign
  	InvalidateWindowClasses(WC_STATION_LIST);
  
  	index = st->index;
  	DeleteWindowById(WC_STATION_VIEW, index);
  
  	//Now delete all orders that go to the station
  	order.type = OT_GOTO_STATION;
  	order.station = index;
  	DeleteDestinationFromVehicleOrder(order);
  
  	//And do the same with aircraft that have the station as a hangar-stop
  	FOR_ALL_VEHICLES(v) {
  		bool invalidate = false;
  		if (v->type == VEH_Aircraft) {
  			Order *order;
  			FOR_VEHICLE_ORDERS(v, order) {
  				if (order->type == OT_GOTO_DEPOT && order->station == index) {
  					order->type = OT_DUMMY;
  					order->flags = 0;
  					invalidate = true;
  				}
  			}
  		}
  		//Orders for the vehicle have been changed, invalidate the window
  		if (invalidate) InvalidateWindow(WC_VEHICLE_ORDERS, v->index);
  	}
  
  	//Subsidies need removal as well
  	DeleteSubsidyWithStation(index);
  
  	st->airport_queue->clear(st->airport_queue);
  	free(st->airport_queue);
  
  	st->helicopter_queue->clear(st->helicopter_queue);
  	free(st->helicopter_queue);
  
  }
  
  void DeleteAllPlayerStations(void)
  {
  	Station *st;
  
  	FOR_ALL_STATIONS(st) {
  		if (st->xy != 0 && st->owner < MAX_PLAYERS) DeleteStation(st);
  	}
  }
  
  static void CheckOrphanedSlots(const Station *st, RoadStopType rst)
  {
  	RoadStop *rs;
  	int k;
  
  	for (rs = GetPrimaryRoadStop(st, rst); rs != NULL; rs = rs->next) {
  		for (k = 0; k < NUM_SLOTS; k++) {
  			if (rs->slot[k] != INVALID_SLOT) {
  				const Vehicle *v = GetVehicle(rs->slot[k]);
  
  				if (v->type != VEH_Road || v->u.road.slot != rs) {
  					DEBUG(ms, 0) (
  						"Multistop: Orphaned %s slot at 0x%X of station %d (don't panic)",
  						(rst == RS_BUS) ? "bus" : "truck", rs->xy, st->index);
  					rs->slot[k] = INVALID_SLOT;
  				}
  			}
  		}
  	}
  }
  
  /* this function is called for one station each tick */
  static void StationHandleBigTick(Station *st)
  {
  	UpdateStationAcceptance(st, true);
  
  	if (st->facilities == 0 && ++st->delete_ctr >= 8) DeleteStation(st);
  
  	// Here we saveguard against orphaned slots
  	CheckOrphanedSlots(st, RS_BUS);
  	CheckOrphanedSlots(st, RS_TRUCK);
  }
  
  static inline void byte_inc_sat(byte *p) { byte b = *p + 1; if (b != 0) *p = b; }
  
  static void UpdateStationRating(Station *st)
  {
  	GoodsEntry *ge;
  	int rating;
  	StationID index;
  	int waiting;
  	bool waiting_changed = false;
  
  	byte_inc_sat(&st->time_since_load);
  	byte_inc_sat(&st->time_since_unload);
  
  	ge = st->goods;
  	do {
  		if (ge->enroute_from != INVALID_STATION) {
  			byte_inc_sat(&ge->enroute_time);
  			byte_inc_sat(&ge->days_since_pickup);
  
  			rating = 0;
  
  			{
  				int b = ge->last_speed;
  				if ((b-=85) >= 0)
  					rating += b >> 2;
  			}
  
  			{
  				byte age = ge->last_age;
  				(age >= 3) ||
  				(rating += 10, age >= 2) ||
  				(rating += 10, age >= 1) ||
  				(rating += 13, true);
  			}
  
  			if (st->owner < MAX_PLAYERS && HASBIT(st->town->statues, st->owner))
  				rating += 26;
  
  			{
  				byte days = ge->days_since_pickup;
  				if (st->last_vehicle != INVALID_VEHICLE &&
  						GetVehicle(st->last_vehicle)->type == VEH_Ship)
  							days >>= 2;
  				(days > 21) ||
  				(rating += 25, days > 12) ||
  				(rating += 25, days > 6) ||
  				(rating += 45, days > 3) ||
  				(rating += 35, true);
  			}
  
  			{
  				waiting = GB(ge->waiting_acceptance, 0, 12);
  				(rating -= 90, waiting > 1500) ||
  				(rating += 55, waiting > 1000) ||
  				(rating += 35, waiting > 600) ||
  				(rating += 10, waiting > 300) ||
  				(rating += 20, waiting > 100) ||
  				(rating += 10, true);
  			}
  
  			{
  				int or = ge->rating; // old rating
  
  				// only modify rating in steps of -2, -1, 0, 1 or 2
  				ge->rating = rating = or + clamp(clamp(rating, 0, 255) - or, -2, 2);
  
  				// if rating is <= 64 and more than 200 items waiting, remove some random amount of goods from the station
  				if (rating <= 64 && waiting >= 200) {
  					int dec = Random() & 0x1F;
  					if (waiting < 400) dec &= 7;
  					waiting -= dec + 1;
  					waiting_changed = true;
  				}
  
  				// if rating is <= 127 and there are any items waiting, maybe remove some goods.
  				if (rating <= 127 && waiting != 0) {
  					uint32 r = Random();
  					if ( (uint)rating <= (r & 0x7F) ) {
  						waiting = max(waiting - ((r >> 8)&3) - 1, 0);
  						waiting_changed = true;
  					}
  				}
  
  				if (waiting_changed) SB(ge->waiting_acceptance, 0, 12, waiting);
  			}
  		}
  	} while (++ge != endof(st->goods));
  
  	index = st->index;
  
  	if (waiting_changed)
  		InvalidateWindow(WC_STATION_VIEW, index);
  	else
  		InvalidateWindowWidget(WC_STATION_VIEW, index, 5);
  }
  
  /* called for every station each tick */
  static void StationHandleSmallTick(Station *st)
  {
  	byte b;
  
  	if (st->facilities == 0) return;
  
  	b = st->delete_ctr + 1;
  	if (b >= 185) b = 0;
  	st->delete_ctr = b;
  
  	if (b == 0) UpdateStationRating(st);
  }
  
  void OnTick_Station(void)
  {
  	uint i;
  	Station *st;
  
  	if (_game_mode == GM_EDITOR) return;
  
  	i = _station_tick_ctr;
  	if (++_station_tick_ctr == GetStationPoolSize()) _station_tick_ctr = 0;
  
  	st = GetStation(i);
  	if (st->xy != 0) StationHandleBigTick(st);
  
  	FOR_ALL_STATIONS(st) {
  		if (st->xy != 0) StationHandleSmallTick(st);
  	}
  }
  
  void StationMonthlyLoop(void)
  {
  }
  
  
  void ModifyStationRatingAround(TileIndex tile, PlayerID owner, int amount, uint radius)
  {
  	Station *st;
  
  	FOR_ALL_STATIONS(st) {
  		if (st->xy != 0 && st->owner == owner &&
  				DistanceManhattan(tile, st->xy) <= radius) {
  			uint i;
  
  			for (i = 0; i != NUM_CARGO; i++) {
  				GoodsEntry* ge = &st->goods[i];
  
  				if (ge->enroute_from != INVALID_STATION) {
  					ge->rating = clamp(ge->rating + amount, 0, 255);
  				}
  			}
  		}
  	}
  }
  
  static void UpdateStationWaiting(Station *st, int type, uint amount)
  {
  	SB(st->goods[type].waiting_acceptance, 0, 12,
  		min(0xFFF, GB(st->goods[type].waiting_acceptance, 0, 12) + amount)
  	);
  
  	st->goods[type].enroute_time = 0;
  	st->goods[type].enroute_from = st->index;
  	InvalidateWindow(WC_STATION_VIEW, st->index);
  }
  
  /** Rename a station
   * @param x,y unused
   * @param p1 station ID that is to be renamed
   * @param p2 unused
   */
  int32 CmdRenameStation(int x, int y, uint32 flags, uint32 p1, uint32 p2)
  {
  	StringID str;
  	Station *st;
  
  	if (!IsStationIndex(p1) || _cmd_text[0] == '\0') return CMD_ERROR;
  	st = GetStation(p1);
  
  	if (!IsValidStation(st) || !CheckOwnership(st->owner)) return CMD_ERROR;
  
  	str = AllocateNameUnique(_cmd_text, 6);
  	if (str == 0) return CMD_ERROR;
  
  	if (flags & DC_EXEC) {
  		StringID old_str = st->string_id;
  
  		st->string_id = str;
  		UpdateStationVirtCoord(st);
  		DeleteName(old_str);
  		_station_sort_dirty[st->owner] = true; // rename a station
  		MarkWholeScreenDirty();
  	} else {
  		DeleteName(str);
  	}
  
  	return 0;
  }
  
  
  uint MoveGoodsToStation(TileIndex tile, int w, int h, int type, uint amount)
  {
  	Station *around_ptr[8];
  	StationID around[8];
  	StationID st_index;
  	int i;
  	Station *st;
  	uint moved;
  	uint best_rating, best_rating2;
  	Station *st1, *st2;
  	int t;
  	int rad=0;
  	int w_prod=0, h_prod=0; //width and height of the "producer" of the cargo
  	int x_min_prod, x_max_prod;     //min and max coordinates of the producer
  	int y_min_prod, y_max_prod;     //relative
  	int x_dist, y_dist;
  	int max_rad;
  
  
  	memset(around, 0xff, sizeof(around));
  
  	if (_patches.modified_catchment) {
  		w_prod = w;
  		h_prod = h;
  		w += 16;
  		h += 16;
  		max_rad = 8;
  	} else {
   		w += 8;
   		h += 8;
  		max_rad = 4;
  	}
  
  	BEGIN_TILE_LOOP(cur_tile, w, h, tile - TileDiffXY(max_rad, max_rad))
  		cur_tile = TILE_MASK(cur_tile);
  		if (IsTileType(cur_tile, MP_STATION)) {
  			st_index = _m[cur_tile].m2;
  			for (i = 0; i != 8; i++) {
  				if (around[i] == INVALID_STATION) {
  					st = GetStation(st_index);
  					if (!IsBuoy(st) &&
  							( !st->town->exclusive_counter || (st->town->exclusivity == st->owner) ) && // check exclusive transport rights
  							st->goods[type].rating != 0 &&
  							(!_patches.selectgoods || st->goods[type].last_speed) && // if last_speed is 0, no vehicle has been there.
  							((st->facilities & (byte)~FACIL_BUS_STOP)!=0 || type==CT_PASSENGERS) && // if we have other fac. than a bus stop, or the cargo is passengers
  							((st->facilities & (byte)~FACIL_TRUCK_STOP)!=0 || type!=CT_PASSENGERS)) { // if we have other fac. than a cargo bay or the cargo is not passengers
  								if (_patches.modified_catchment) {
  									rad = FindCatchmentRadius(st);
  									x_min_prod = y_min_prod = 9;
  									x_max_prod = 8 + w_prod;
  									y_max_prod = 8 + h_prod;
  
  									x_dist = min(w_cur - x_min_prod, x_max_prod - w_cur);
  
  									if (w_cur < x_min_prod) {
  										x_dist = x_min_prod - w_cur;
  									} else {        //save cycles
  										if (w_cur > x_max_prod) x_dist = w_cur - x_max_prod;
  									}
  
  									y_dist = min(h_cur - y_min_prod, y_max_prod - h_cur);
  									if (h_cur < y_min_prod) {
  										y_dist = y_min_prod - h_cur;
  									} else {
  										if (h_cur > y_max_prod) y_dist = h_cur - y_max_prod;
  									}
  
  								} else {
  									x_dist = y_dist = 0;
  								}
  
  								if ( !(x_dist > rad) && !(y_dist > rad) ) {
  
  									around[i] = st_index;
  									around_ptr[i] = st;
  								}
  							}
  					break;
  				} else if (around[i] == st_index)
  					break;
  			}
  		}
  	END_TILE_LOOP(cur_tile, w, h, tile - TileDiffXY(max_rad, max_rad))
  
  	/* no stations around at all? */
  	if (around[0] == INVALID_STATION)
  		return 0;
  
  	if (around[1] == INVALID_STATION) {
  		/* only one station around */
  		moved = (amount * around_ptr[0]->goods[type].rating >> 8) + 1;
  		UpdateStationWaiting(around_ptr[0], type, moved);
  		return moved;
  	}
  
  	/* several stations around, find the two with the highest rating */
  	st2 = st1 = NULL;
  	best_rating = best_rating2 = 0;
  
  	for( i = 0; i != 8 && around[i] != INVALID_STATION; i++) {
  		if (around_ptr[i]->goods[type].rating >= best_rating) {
  			best_rating2 = best_rating;
  			st2 = st1;
  
  			best_rating = around_ptr[i]->goods[type].rating;
  			st1 = around_ptr[i];
  		} else if (around_ptr[i]->goods[type].rating >= best_rating2) {
  			best_rating2 = around_ptr[i]->goods[type].rating;
  			st2 = around_ptr[i];
  		}
  	}
  
  	assert(st1 != NULL);
  	assert(st2 != NULL);
  	assert(best_rating != 0 || best_rating2 != 0);
  
  	/* the 2nd highest one gets a penalty */
  	best_rating2 >>= 1;
  
  	/* amount given to station 1 */
  	t = (best_rating * (amount + 1)) / (best_rating + best_rating2);
  
  	moved = 0;
  	if (t != 0) {
  		moved = (t * best_rating >> 8) + 1;
  		amount -= t;
  		UpdateStationWaiting(st1, type, moved);
  	}
  
  	if (amount != 0) {
  		moved += (amount = (amount * best_rating2 >> 8) + 1);
  		UpdateStationWaiting(st2, type, amount);
  	}
  
  	return moved;
  }
  
  void BuildOilRig(TileIndex tile)
  {
  	uint j;
  	Station *st = AllocateStation();
  
  	if (st == NULL) {
  		DEBUG(misc, 0) ("Couldn't allocate station for oilrig at %#X, reverting to oilrig only...", tile);
  		return;
  	}
  	if (!GenerateStationName(st, tile, 2)) {
  		DEBUG(misc, 0) ("Couldn't allocate station-name for oilrig at %#X, reverting to oilrig only...", tile);
  		return;
  	}
  
  	st->town = ClosestTownFromTile(tile, (uint)-1);
  	st->sign.width_1 = 0;
  
  	SetTileType(tile, MP_STATION);
  	SetTileOwner(tile, OWNER_NONE);
  	_m[tile].m2 = st->index;
  	_m[tile].m3 = 0;
  	_m[tile].m4 = 0;
  	_m[tile].m5 = 0x4B;
  
  	st->owner = OWNER_NONE;
  	st->airport_flags = 0;
  	st->airport_type = AT_OILRIG;
  	st->xy = tile;
  	st->bus_stops = NULL;
  	st->truck_stops = NULL;
  	st->airport_tile = tile;
  	st->dock_tile = tile;
  	st->train_tile = 0;
  	st->had_vehicle_of_type = 0;
  	st->time_since_load = 255;
  	st->time_since_unload = 255;
  	st->delete_ctr = 0;
  	st->last_vehicle = INVALID_VEHICLE;
  	st->facilities = FACIL_AIRPORT | FACIL_DOCK;
  	st->build_date = _date;
  
  	for (j = 0; j != NUM_CARGO; j++) {
  		st->goods[j].waiting_acceptance = 0;
  		st->goods[j].days_since_pickup = 0;
  		st->goods[j].enroute_from = INVALID_STATION;
  		st->goods[j].rating = 175;
  		st->goods[j].last_speed = 0;
  		st->goods[j].last_age = 255;
  	}
  
  	UpdateStationVirtCoordDirty(st);
  	UpdateStationAcceptance(st, false);
  }
  
  void DeleteOilRig(TileIndex tile)
  {
  	Station *st = GetStation(_m[tile].m2);
  
  	DoClearSquare(tile);
  
  	st->dock_tile = 0;
  	st->airport_tile = 0;
  	st->facilities &= ~(FACIL_AIRPORT | FACIL_DOCK);
  	st->airport_flags = 0;
  	UpdateStationVirtCoordDirty(st);
  	DeleteStation(st);
  }
  
  static void ChangeTileOwner_Station(TileIndex tile, PlayerID old_player, PlayerID new_player)
  {
  	if (!IsTileOwner(tile, old_player)) return;
  
  	if (new_player != OWNER_SPECTATOR) {
  		Station *st = GetStation(_m[tile].m2);
  		SetTileOwner(tile, new_player);
  		st->owner = new_player;
  		_global_station_sort_dirty = true; // transfer ownership of station to another player
  		InvalidateWindowClasses(WC_STATION_LIST);
  	} else {
  		DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
  	}
  }
  
  static int32 ClearTile_Station(TileIndex tile, byte flags)
  {
  	byte m5 = _m[tile].m5;
  	Station *st;
  
  	if (flags & DC_AUTO) {
  		if (m5 < 8) return_cmd_error(STR_300B_MUST_DEMOLISH_RAILROAD);
  		if (m5 < 0x43 || (m5 >= 83 && m5 <= 114)) return_cmd_error(STR_300E_MUST_DEMOLISH_AIRPORT_FIRST);
  		if (m5 < 0x47) return_cmd_error(STR_3047_MUST_DEMOLISH_TRUCK_STATION);
  		if (m5 < 0x4B) return_cmd_error(STR_3046_MUST_DEMOLISH_BUS_STATION);
  		if (m5 == 0x52) return_cmd_error(STR_306A_BUOY_IN_THE_WAY);
  		if (m5 != 0x4B && m5 < 0x53) return_cmd_error(STR_304D_MUST_DEMOLISH_DOCK_FIRST);
  		SetDParam(0, STR_4807_OIL_RIG);
  		return_cmd_error(STR_4800_IN_THE_WAY);
  	}
  
  	st = GetStation(_m[tile].m2);
  
  	if (m5 < 8) return RemoveRailroadStation(st, tile, flags);
  	// original airports < 67, new airports between 83 - 114
  	if (m5 < 0x43 || (m5 >= 83 && m5 <= 114)) return RemoveAirport(st, flags);
  	if (m5 < 0x4B) return RemoveRoadStop(st, flags, tile);
  	if (m5 == 0x52) return RemoveBuoy(st, flags);
  	if (m5 != 0x4B && m5 < 0x53) return RemoveDock(st, flags);
  
  	return CMD_ERROR;
  }
  
  void InitializeStations(void)
  {
  	/* Clean the station pool and create 1 block in it */
  	CleanPool(&_station_pool);
  	AddBlockToPool(&_station_pool);
  
  	/* Clean the roadstop pool and create 1 block in it */
  	CleanPool(&_roadstop_pool);
  	AddBlockToPool(&_roadstop_pool);
  
  	_station_tick_ctr = 0;
  
  	// set stations to be sorted on load of savegame
  	memset(_station_sort_dirty, true, sizeof(_station_sort_dirty));
  	_global_station_sort_dirty = true; // load of savegame
  }
  
  
  const TileTypeProcs _tile_type_station_procs = {
  	DrawTile_Station,						/* draw_tile_proc */
  	GetSlopeZ_Station,					/* get_slope_z_proc */
  	ClearTile_Station,					/* clear_tile_proc */
  	GetAcceptedCargo_Station,		/* get_accepted_cargo_proc */
  	GetTileDesc_Station,				/* get_tile_desc_proc */
  	GetTileTrackStatus_Station,	/* get_tile_track_status_proc */
  	ClickTile_Station,					/* click_tile_proc */
  	AnimateTile_Station,				/* animate_tile_proc */
  	TileLoop_Station,						/* tile_loop_clear */
  	ChangeTileOwner_Station,		/* change_tile_owner_clear */
  	NULL,												/* get_produced_cargo_proc */
  	VehicleEnter_Station,				/* vehicle_enter_tile_proc */
  	NULL,												/* vehicle_leave_tile_proc */
  	GetSlopeTileh_Station,			/* get_slope_tileh_proc */
  };
  
  static const SaveLoad _roadstop_desc[] = {
  	SLE_VAR(RoadStop,xy,           SLE_UINT32),
  	SLE_VAR(RoadStop,used,         SLE_UINT8),
  	SLE_VAR(RoadStop,status,       SLE_UINT8),
  	/* Index was saved in some versions, but this is not needed */
  	SLE_CONDARR(NullStruct,null,SLE_FILE_U32 | SLE_VAR_NULL, 1, 0, 8),
  	SLE_VAR(RoadStop,station,      SLE_UINT16),
  	SLE_VAR(RoadStop,type,         SLE_UINT8),
  
  	SLE_REF(RoadStop,next,         REF_ROADSTOPS),
  	SLE_REF(RoadStop,prev,         REF_ROADSTOPS),
  
  	SLE_ARR(RoadStop,slot,         SLE_UINT16, NUM_SLOTS),
  
  	SLE_END()
  };
  
  static const SaveLoad _station_desc[] = {
  	SLE_CONDVAR(Station, xy,           SLE_FILE_U16 | SLE_VAR_U32, 0, 5),
  	SLE_CONDVAR(Station, xy,           SLE_UINT32, 6, 255),
  	SLE_CONDVAR(Station, bus_tile_obsolete,    SLE_FILE_U16 | SLE_VAR_U32, 0, 5),
  	SLE_CONDVAR(Station, lorry_tile_obsolete,  SLE_FILE_U16 | SLE_VAR_U32, 0, 5),
  	SLE_CONDVAR(Station, train_tile,   SLE_FILE_U16 | SLE_VAR_U32, 0, 5),
  	SLE_CONDVAR(Station, train_tile,   SLE_UINT32, 6, 255),
  	SLE_CONDVAR(Station, airport_tile, SLE_FILE_U16 | SLE_VAR_U32, 0, 5),
  	SLE_CONDVAR(Station, airport_tile, SLE_UINT32, 6, 255),
  	SLE_CONDVAR(Station, dock_tile,    SLE_FILE_U16 | SLE_VAR_U32, 0, 5),
  	SLE_CONDVAR(Station, dock_tile,    SLE_UINT32, 6, 255),
  	SLE_REF(Station,town,						REF_TOWN),
  	SLE_VAR(Station,trainst_w,			SLE_UINT8),
  	SLE_CONDVAR(Station,trainst_h,	SLE_UINT8, 2, 255),
  
  	// alpha_order was stored here in savegame format 0 - 3
  	SLE_CONDARR(NullStruct,null,SLE_FILE_U8 | SLE_VAR_NULL, 1, 0, 3),
  
  	SLE_VAR(Station,string_id,			SLE_STRINGID),
  	SLE_VAR(Station,had_vehicle_of_type,SLE_UINT16),
  
  	SLE_VAR(Station,time_since_load,		SLE_UINT8),
  	SLE_VAR(Station,time_since_unload,	SLE_UINT8),
  	SLE_VAR(Station,delete_ctr,					SLE_UINT8),
  	SLE_VAR(Station,owner,							SLE_UINT8),
  	SLE_VAR(Station,facilities,					SLE_UINT8),
  	SLE_VAR(Station,airport_type,				SLE_UINT8),
  
  	// truck/bus_stop_status was stored here in savegame format 0 - 6
  	SLE_CONDVAR(Station,truck_stop_status_obsolete,	SLE_UINT8, 0, 5),
  	SLE_CONDVAR(Station,bus_stop_status_obsolete,		SLE_UINT8, 0, 5),
  
  	// blocked_months was stored here in savegame format 0 - 4.0
  	SLE_CONDVAR(Station,blocked_months_obsolete,	SLE_UINT8, 0, 4),
  
  	SLE_CONDVAR(Station,airport_flags,			SLE_VAR_U32 | SLE_FILE_U16, 0, 2),
  	SLE_CONDVAR(Station,airport_flags,			SLE_UINT32, 3, 255),
  
  	SLE_VAR(Station,last_vehicle,				SLE_UINT16),
  
  	SLE_CONDVAR(Station,class_id,				SLE_UINT8, 3, 255),
  	SLE_CONDVAR(Station,stat_id,				SLE_UINT8, 3, 255),
  	SLE_CONDVAR(Station,build_date,			SLE_UINT16, 3, 255),
  
  	SLE_CONDREF(Station,bus_stops,					REF_ROADSTOPS, 6, 255),
  	SLE_CONDREF(Station,truck_stops,				REF_ROADSTOPS, 6, 255),
  
  	// reserve extra space in savegame here. (currently 28 bytes)
  	SLE_CONDARR(NullStruct,null,SLE_FILE_U8 | SLE_VAR_NULL, 32, 2, 255),
  
  	SLE_END()
  };
  
  static const SaveLoad _goods_desc[] = {
  	SLE_VAR(GoodsEntry,waiting_acceptance,SLE_UINT16),
  	SLE_VAR(GoodsEntry,days_since_pickup,	SLE_UINT8),
  	SLE_VAR(GoodsEntry,rating,						SLE_UINT8),
  	SLE_CONDVAR(GoodsEntry,enroute_from,			SLE_FILE_U8 | SLE_VAR_U16, 0, 6),
  	SLE_CONDVAR(GoodsEntry,enroute_from,			SLE_UINT16, 7, 255),
  	SLE_VAR(GoodsEntry,enroute_time,			SLE_UINT8),
  	SLE_VAR(GoodsEntry,last_speed,				SLE_UINT8),
  	SLE_VAR(GoodsEntry,last_age,					SLE_UINT8),
  	SLE_CONDVAR(GoodsEntry,feeder_profit,			SLE_INT32, 14, 255),
  
  	SLE_END()
  };
  
  
  static void SaveLoad_STNS(Station *st)
  {
  	int i;
  
  	SlObject(st, _station_desc);
  	for (i = 0; i != NUM_CARGO; i++) {
  		SlObject(&st->goods[i], _goods_desc);
  
  		/* In older versions, enroute_from had 0xFF as INVALID_STATION, is now 0xFFFF */
  		if (CheckSavegameVersion(7) && st->goods[i].enroute_from == 0xFF) {
  			st->goods[i].enroute_from = INVALID_STATION;
  		}
  	}
  }
  
  static void Save_STNS(void)
  {
  	Station *st;
  	// Write the stations
  	FOR_ALL_STATIONS(st) {
  		if (st->xy != 0) {
  			SlSetArrayIndex(st->index);
  			SlAutolength((AutolengthProc*)SaveLoad_STNS, st);
  		}
  	}
  }
  
  static void Load_STNS(void)
  {
  	int index;
  	while ((index = SlIterateArray()) != -1) {
  		Station *st;
  
  		if (!AddBlockIfNeeded(&_station_pool, index))
  			error("Stations: failed loading savegame: too many stations");
  
  		st = GetStation(index);
  		SaveLoad_STNS(st);
  
  		// this means it's an oldstyle savegame without support for nonuniform stations
  		if (st->train_tile != 0 && st->trainst_h == 0) {
  			int w = GB(st->trainst_w, 4, 4);
  			int h = GB(st->trainst_w, 0, 4);
  
  			if (_m[st->train_tile].m5 & 1) intswap(w, h);
  			st->trainst_w = w;
  			st->trainst_h = h;
  		}
  
  		/* In older versions, we had just 1 tile for a bus/lorry, now we have more..
  		 *  convert, if needed */
  		if (CheckSavegameVersion(6)) {
  			if (st->bus_tile_obsolete != 0) {
  				st->bus_stops = AllocateRoadStop();
  				if (st->bus_stops == NULL)
  					error("Station: too many busstations in savegame");
  
  				InitializeRoadStop(st->bus_stops, NULL, st->bus_tile_obsolete, st->index);
  			}
  			if (st->lorry_tile_obsolete != 0) {
  				st->truck_stops = AllocateRoadStop();
  				if (st->truck_stops == NULL)
  					error("Station: too many truckstations in savegame");
  
  				InitializeRoadStop(st->truck_stops, NULL, st->lorry_tile_obsolete, st->index);
  			}
  		}
  
  	st->airport_queue = new_VQueue();
  	st->helicopter_queue = new_VQueue();
  	}
  
  	/* This is to ensure all pointers are within the limits of _stations_size */
  	if (_station_tick_ctr > GetStationPoolSize()) _station_tick_ctr = 0;
  }
  
  static void Save_ROADSTOP(void)
  {
  	RoadStop *rs;
  
  	FOR_ALL_ROADSTOPS(rs) {
  		if (rs->used) {
  			SlSetArrayIndex(rs->index);
  			SlObject(rs, _roadstop_desc);
  		}
  	}
  }
  
  static void Load_ROADSTOP(void)
  {
  	int index;
  
  	while ((index = SlIterateArray()) != -1) {
  		RoadStop *rs;
  
  		if (!AddBlockIfNeeded(&_roadstop_pool, index))
  			error("RoadStops: failed loading savegame: too many RoadStops");
  
  		rs = GetRoadStop(index);
  		SlObject(rs, _roadstop_desc);
  	}
  }
  
  const ChunkHandler _station_chunk_handlers[] = {
  	{ 'STNS', Save_STNS,      Load_STNS,      CH_ARRAY },
  	{ 'ROAD', Save_ROADSTOP,  Load_ROADSTOP,  CH_ARRAY | CH_LAST},
  };
  