diff --git a/ai_old.c b/ai_old.c
new file mode 100644
--- /dev/null
+++ b/ai_old.c
@@ -0,0 +1,3998 @@
+#include "stdafx.h"
+#include "openttd.h"
+#include "map.h"
+#include "tile.h"
+#include "player.h"
+#include "vehicle.h"
+#include "engine.h"
+#include "command.h"
+#include "town.h"
+#include "industry.h"
+#include "station.h"
+#include "pathfind.h"
+#include "economy.h"
+#include "airport.h"
+#include "depot.h"
+
+// remove some day perhaps?
+static Player *_cur_ai_player;
+static uint _ai_service_interval;
+
+typedef void AiStateAction(Player *p);
+
+enum {
+	AIS_0 = 0,
+	AIS_1 = 1,
+	AIS_VEH_LOOP = 2,
+	AIS_VEH_CHECK_REPLACE_VEHICLE = 3,
+	AIS_VEH_DO_REPLACE_VEHICLE = 4,
+	AIS_WANT_NEW_ROUTE = 5,
+	AIS_BUILD_DEFAULT_RAIL_BLOCKS = 6,
+	AIS_BUILD_RAIL = 7,
+	AIS_BUILD_RAIL_VEH = 8,
+	AIS_DELETE_RAIL_BLOCKS = 9,
+	AIS_BUILD_DEFAULT_ROAD_BLOCKS = 10,
+	AIS_BUILD_ROAD = 11,
+	AIS_BUILD_ROAD_VEHICLES = 12,
+	AIS_DELETE_ROAD_BLOCKS = 13,
+	AIS_AIRPORT_STUFF = 14,
+	AIS_BUILD_DEFAULT_AIRPORT_BLOCKS = 15,
+	AIS_BUILD_AIRCRAFT_VEHICLES = 16,
+	AIS_CHECK_SHIP_STUFF = 17,
+	AIS_BUILD_DEFAULT_SHIP_BLOCKS = 18,
+	AIS_DO_SHIP_STUFF = 19,
+	AIS_SELL_VEHICLE = 20,
+	AIS_REMOVE_STATION = 21,
+	AIS_REMOVE_TRACK = 22,
+	AIS_REMOVE_SINGLE_RAIL_TILE = 23
+};
+
+
+#include "table/ai_rail.h"
+
+static byte GetRailTrackStatus(TileIndex tile) {
+	uint32 r = GetTileTrackStatus(tile, TRANSPORT_RAIL);
+	return (byte) (r | r >> 8);
+}
+
+
+static void AiCase0(Player *p)
+{
+	p->ai.state = AIS_REMOVE_TRACK;
+	p->ai.state_counter = 0;
+}
+
+static void AiCase1(Player *p)
+{
+	p->ai.cur_veh = NULL;
+	p->ai.state = AIS_VEH_LOOP;
+}
+
+static void AiStateVehLoop(Player *p)
+{
+	Vehicle *v;
+	uint index;
+
+	index = (p->ai.cur_veh == NULL) ? 0 : p->ai.cur_veh->index + 1;
+
+	FOR_ALL_VEHICLES_FROM(v, index) {
+		if (v->type == 0 || v->owner != _current_player)
+			continue;
+
+		if ((v->type == VEH_Train && v->subtype==0) ||
+				v->type == VEH_Road ||
+				(v->type == VEH_Aircraft && v->subtype <= 2) ||
+				v->type == VEH_Ship) {
+
+			/* replace engine? */
+			if (v->type == VEH_Train && v->engine_type < 3 &&
+					(_price.build_railvehicle >> 3) < p->player_money) {
+				p->ai.state = AIS_VEH_CHECK_REPLACE_VEHICLE;
+				p->ai.cur_veh = v;
+				return;
+			}
+
+			/* not profitable? */
+			if (v->age >= 730 &&
+					v->profit_last_year < _price.station_value*5 &&
+					v->profit_this_year < _price.station_value*5) {
+				p->ai.state_counter = 0;
+				p->ai.state = AIS_SELL_VEHICLE;
+				p->ai.cur_veh = v;
+				return;
+			}
+
+			/* not reliable? */
+			if ((v->age != 0 &&
+					GetEngine(v->engine_type)->reliability < 35389) ||
+					v->age >= v->max_age) {
+				p->ai.state = AIS_VEH_CHECK_REPLACE_VEHICLE;
+				p->ai.cur_veh = v;
+				return;
+			}
+		}
+	}
+
+	p->ai.state = AIS_WANT_NEW_ROUTE;
+	p->ai.state_counter = 0;
+}
+
+static int AiChooseTrainToBuild(byte railtype, int32 money, byte flag, TileIndex tile)
+{
+	int best_veh_index = -1;
+	byte best_veh_score = 0;
+	int32 ret;
+	int i;
+
+	for (i = 0; i < NUM_TRAIN_ENGINES; i++) {
+		const RailVehicleInfo *rvi = RailVehInfo(i);
+		const Engine* e = GetEngine(i);
+
+		if (e->railtype != railtype || rvi->flags & RVI_WAGON
+		    || !HASBIT(e->player_avail, _current_player) || e->reliability < 0x8A3D)
+			continue;
+
+		ret = DoCommandByTile(tile, i, 0, 0, CMD_BUILD_RAIL_VEHICLE);
+		if (!CmdFailed(ret) && (!(_cmd_build_rail_veh_var1&1) || !(flag&1)) && ret <= money &&
+				_cmd_build_rail_veh_score >= best_veh_score) {
+			best_veh_score = _cmd_build_rail_veh_score;
+			best_veh_index = i;
+		}
+	}
+
+	return best_veh_index;
+}
+
+static int AiChooseRoadVehToBuild(byte cargo, int32 money, TileIndex tile)
+{
+	int best_veh_index = -1;
+	int32 best_veh_cost = 0;
+	int32 ret;
+
+	int i = _cargoc.ai_roadveh_start[cargo];
+	int end = i + _cargoc.ai_roadveh_count[cargo];
+	const Engine* e = GetEngine(i);
+
+	do {
+		if (!HASBIT(e->player_avail, _current_player) || e->reliability < 0x8A3D)
+			continue;
+
+		ret = DoCommandByTile(tile, i, 0, 0, CMD_BUILD_ROAD_VEH);
+		if (!CmdFailed(ret) && ret <= money && ret >= best_veh_cost) {
+			best_veh_cost = ret;
+			best_veh_index = i;
+		}
+	} while (++e, ++i != end);
+
+	return best_veh_index;
+}
+
+static int AiChooseAircraftToBuild(int32 money, byte flag)
+{
+	int best_veh_index = -1;
+	int32 best_veh_cost = 0;
+	int32 ret;
+
+	int i = AIRCRAFT_ENGINES_INDEX;
+	int end = i + NUM_AIRCRAFT_ENGINES;
+	const Engine* e = GetEngine(i);
+
+	do {
+		if (!HASBIT(e->player_avail, _current_player) || e->reliability < 0x8A3D)
+			continue;
+
+		if (flag&1) {
+			if (i<253) continue;
+		} else {
+			if (i>=253) continue;
+		}
+
+		ret = DoCommandByTile(0, i, 0, 0, CMD_BUILD_AIRCRAFT);
+		if (!CmdFailed(ret) && ret <= money && ret >= best_veh_cost) {
+			best_veh_cost = ret;
+			best_veh_index = i;
+		}
+	} while (++e, ++i != end);
+
+	return best_veh_index;
+}
+
+static int32 AiGetBasePrice(Player *p)
+{
+	int32 base = _price.station_value;
+
+	// adjust base price when more expensive vehicles are available
+	if (p->ai.railtype_to_use == 1) base = (base * 3) >> 1;
+	else if (p->ai.railtype_to_use == 2) base *= 2;
+
+	return base;
+}
+
+#if 0
+static int AiChooseShipToBuild(byte cargo, int32 money)
+{
+	// XXX: not done
+	return 0;
+}
+#endif
+
+static int AiChooseRoadVehToReplaceWith(Player *p, Vehicle *v)
+{
+	int32 avail_money = p->player_money + v->value;
+	return AiChooseRoadVehToBuild(v->cargo_type, avail_money, v->tile);
+}
+
+static int AiChooseAircraftToReplaceWith(Player *p, Vehicle *v)
+{
+	int32 avail_money = p->player_money + v->value;
+	return AiChooseAircraftToBuild(avail_money, v->engine_type>=253?1:0);
+}
+
+static int AiChooseTrainToReplaceWith(Player *p, Vehicle *v)
+{
+	int32 avail_money = p->player_money + v->value;
+	int num=0;
+	Vehicle *u = v;
+
+	while (++num, u->next != NULL) {
+		u = u->next;
+	}
+
+	// XXX: check if a wagon
+	return AiChooseTrainToBuild(v->u.rail.railtype, avail_money, 0, v->tile);
+}
+
+static int AiChooseShipToReplaceWith(Player *p, Vehicle *v)
+{
+	error("!AiChooseShipToReplaceWith");
+
+	/* maybe useless, but avoids compiler warning this way */
+	return 0;
+}
+
+static void AiHandleGotoDepot(Player *p, int cmd)
+{
+	if (p->ai.cur_veh->current_order.type != OT_GOTO_DEPOT)
+		DoCommandByTile(0, p->ai.cur_veh->index, 0, DC_EXEC, cmd);
+
+	if (++p->ai.state_counter <= 1387) {
+		p->ai.state = AIS_VEH_DO_REPLACE_VEHICLE;
+		return;
+	}
+
+	if (p->ai.cur_veh->current_order.type == OT_GOTO_DEPOT) {
+		p->ai.cur_veh->current_order.type = OT_DUMMY;
+		p->ai.cur_veh->current_order.flags = 0;
+		InvalidateWindow(WC_VEHICLE_VIEW, p->ai.cur_veh->index);
+	}
+}
+
+static void AiRestoreVehicleOrders(Vehicle *v, BackuppedOrders *bak)
+{
+	int i;
+
+	for (i = 0; bak->order[i].type != OT_NOTHING; i++)
+		if (CmdFailed(DoCommandP(0, v->index + (i << 16), PackOrder(&bak->order[i]), NULL, CMD_INSERT_ORDER | CMD_NO_TEST_IF_IN_NETWORK)))
+			break;
+}
+
+static void AiHandleReplaceTrain(Player *p)
+{
+	Vehicle *v = p->ai.cur_veh;
+	BackuppedOrders orderbak[1];
+	int veh;
+
+	// wait until the vehicle reaches the depot.
+	if (!IsTileDepotType(v->tile, TRANSPORT_RAIL) || v->u.rail.track != 0x80 || !(v->vehstatus&VS_STOPPED)) {
+		AiHandleGotoDepot(p, CMD_TRAIN_GOTO_DEPOT);
+		return;
+	}
+
+	veh = AiChooseTrainToReplaceWith(p, v);
+	if (veh != -1) {
+		TileIndex tile;
+
+		BackupVehicleOrders(v, orderbak);
+		tile = v->tile;
+
+		if (!CmdFailed(DoCommandByTile(0, v->index, 2, DC_EXEC, CMD_SELL_RAIL_WAGON)) &&
+			  !CmdFailed(DoCommandByTile(tile, veh, 0, DC_EXEC, CMD_BUILD_RAIL_VEHICLE)) ) {
+			veh = _new_train_id;
+			AiRestoreVehicleOrders(GetVehicle(veh), orderbak);
+			DoCommandByTile(0, veh, 0, DC_EXEC, CMD_START_STOP_TRAIN);
+
+			DoCommandByTile(0, veh, _ai_service_interval, DC_EXEC, CMD_CHANGE_TRAIN_SERVICE_INT);
+		}
+	}
+}
+
+static void AiHandleReplaceRoadVeh(Player *p)
+{
+	Vehicle *v = p->ai.cur_veh;
+	BackuppedOrders orderbak[1];
+	int veh;
+
+	if (!IsTileDepotType(v->tile, TRANSPORT_ROAD) || v->u.road.state != 254 || !(v->vehstatus&VS_STOPPED)) {
+		AiHandleGotoDepot(p, CMD_SEND_ROADVEH_TO_DEPOT);
+		return;
+	}
+
+	veh = AiChooseRoadVehToReplaceWith(p, v);
+	if (veh != -1) {
+		TileIndex tile;
+
+		BackupVehicleOrders(v, orderbak);
+		tile = v->tile;
+
+		if (!CmdFailed(DoCommandByTile(0, v->index, 0, DC_EXEC, CMD_SELL_ROAD_VEH)) &&
+			  !CmdFailed(DoCommandByTile(tile, veh, 0, DC_EXEC, CMD_BUILD_ROAD_VEH)) ) {
+			veh = _new_roadveh_id;
+			AiRestoreVehicleOrders(GetVehicle(veh), orderbak);
+			DoCommandByTile(0, veh, 0, DC_EXEC, CMD_START_STOP_ROADVEH);
+
+			DoCommandByTile(0, veh, _ai_service_interval, DC_EXEC, CMD_CHANGE_TRAIN_SERVICE_INT);
+		}
+	}
+}
+
+static void AiHandleReplaceAircraft(Player *p)
+{
+	Vehicle *v = p->ai.cur_veh;
+	int veh;
+	BackuppedOrders orderbak[1];
+
+	if (!IsAircraftHangarTile(v->tile) && !(v->vehstatus&VS_STOPPED)) {
+		AiHandleGotoDepot(p, CMD_SEND_AIRCRAFT_TO_HANGAR);
+		return;
+	}
+
+	veh = AiChooseAircraftToReplaceWith(p, v);
+	if (veh != -1) {
+		TileIndex tile;
+
+		BackupVehicleOrders(v, orderbak);
+		tile = v->tile;
+
+		if (!CmdFailed(DoCommandByTile(0, v->index, 0, DC_EXEC, CMD_SELL_AIRCRAFT)) &&
+			  !CmdFailed(DoCommandByTile(tile, veh, 0, DC_EXEC, CMD_BUILD_AIRCRAFT)) ) {
+			veh = _new_aircraft_id;
+			AiRestoreVehicleOrders(GetVehicle(veh), orderbak);
+			DoCommandByTile(0, veh, 0, DC_EXEC, CMD_START_STOP_AIRCRAFT);
+
+			DoCommandByTile(0, veh, _ai_service_interval, DC_EXEC, CMD_CHANGE_TRAIN_SERVICE_INT);
+		}
+	}
+}
+
+static void AiHandleReplaceShip(Player *p)
+{
+	error("!AiHandleReplaceShip");
+}
+
+typedef int CheckReplaceProc(Player *p, Vehicle *v);
+
+static CheckReplaceProc * const _veh_check_replace_proc[] = {
+	AiChooseTrainToReplaceWith,
+	AiChooseRoadVehToReplaceWith,
+	AiChooseShipToReplaceWith,
+	AiChooseAircraftToReplaceWith,
+};
+
+typedef void DoReplaceProc(Player *p);
+static DoReplaceProc * const _veh_do_replace_proc[] = {
+	AiHandleReplaceTrain,
+	AiHandleReplaceRoadVeh,
+	AiHandleReplaceShip,
+	AiHandleReplaceAircraft
+};
+
+static void AiStateCheckReplaceVehicle(Player *p)
+{
+	Vehicle *v = p->ai.cur_veh;
+
+	if (v->type == 0 || v->owner != _current_player || v->type > VEH_Ship || _veh_check_replace_proc[v->type - VEH_Train](p, v) == -1) {
+		p->ai.state = AIS_VEH_LOOP;
+	} else {
+		p->ai.state_counter = 0;
+		p->ai.state = AIS_VEH_DO_REPLACE_VEHICLE;
+	}
+}
+
+static void AiStateDoReplaceVehicle(Player *p)
+{
+	Vehicle *v = p->ai.cur_veh;
+	p->ai.state = AIS_VEH_LOOP;
+	// vehicle is not owned by the player anymore, something went very wrong.
+	if (v->type == 0 || v->owner != _current_player)
+		return;
+	_veh_do_replace_proc[v->type - VEH_Train](p);
+}
+
+typedef struct FoundRoute {
+	int distance;
+	byte cargo;
+	void *from;
+	void *to;
+} FoundRoute;
+
+static Town *AiFindRandomTown(void)
+{
+	Town *t = GetTown(RandomRange(_total_towns));
+	return (t->xy != 0) ? t : NULL;
+}
+
+static Industry *AiFindRandomIndustry(void)
+{
+	Industry *i = GetIndustry(RandomRange(_total_industries));
+	return (i->xy != 0) ? i : NULL;
+}
+
+static void AiFindSubsidyIndustryRoute(FoundRoute *fr)
+{
+	uint i;
+	byte cargo;
+	Subsidy *s;
+	Industry *from, *to_ind;
+	Town *to_tow;
+	TileIndex to_xy;
+
+	// initially error
+	fr->distance = -1;
+
+	// Randomize subsidy index..
+	i = RandomRange(lengthof(_subsidies) * 3);
+	if (i >= lengthof(_subsidies))
+		return;
+
+	s = &_subsidies[i];
+
+	// Don't want passengers or mail
+	cargo = s->cargo_type;
+	if (cargo == 0xFF || cargo == CT_PASSENGERS || cargo == CT_MAIL || s->age > 7)
+		return;
+	fr->cargo = cargo;
+
+	fr->from = from = GetIndustry(s->from);
+
+	if (cargo == CT_GOODS || cargo == CT_FOOD) {
+		to_tow = GetTown(s->to);
+		if (to_tow->population < (uint32)(cargo == CT_FOOD ? 200 : 900))
+			return; // error
+		fr->to = to_tow;
+		to_xy = to_tow->xy;
+	} else {
+		to_ind = GetIndustry(s->to);
+		fr->to = to_ind;
+		to_xy = to_ind->xy;
+	}
+
+	fr->distance = DistanceManhattan(from->xy, to_xy);
+}
+
+static void AiFindSubsidyPassengerRoute(FoundRoute *fr)
+{
+	uint i;
+	Subsidy *s;
+	Town *from,*to;
+
+	// initially error
+	fr->distance = -1;
+
+	// Randomize subsidy index..
+	i = RandomRange(lengthof(_subsidies) * 3);
+	if (i >= lengthof(_subsidies))
+		return;
+
+	s = &_subsidies[i];
+
+	// Only want passengers
+	if (s->cargo_type != CT_PASSENGERS || s->age > 7)
+		return;
+	fr->cargo = s->cargo_type;
+
+	fr->from = from = GetTown(s->from);
+	fr->to = to = GetTown(s->to);
+
+	// They must be big enough
+	if (from->population < 400 || to->population < 400)
+		return;
+
+	fr->distance = DistanceManhattan(from->xy, to->xy);
+}
+
+static void AiFindRandomIndustryRoute(FoundRoute *fr)
+{
+	Industry *i,*i2;
+	Town *t;
+	uint32 r;
+	byte cargo;
+
+	// initially error
+	fr->distance = -1;
+
+	r = Random();
+
+	// pick a source
+	fr->from = i = AiFindRandomIndustry();
+	if (i == NULL)
+		return;
+
+	// pick a random produced cargo
+	cargo = i->produced_cargo[0];
+	if (r&1 && i->produced_cargo[1] != 0xFF)
+		cargo = i->produced_cargo[1];
+
+	fr->cargo = cargo;
+
+	// don't allow passengers
+	if (cargo == 0xFF || cargo == CT_PASSENGERS)
+		return;
+
+	if (cargo != CT_GOODS && cargo != CT_FOOD) {
+		// pick a dest, and see if it can receive
+		i2 = AiFindRandomIndustry();
+		if (i2 == NULL || i == i2 || !(i2->accepts_cargo[0] == cargo || i2->accepts_cargo[1] == cargo || i2->accepts_cargo[2] == cargo))
+			return;
+
+		fr->to = i2;
+		fr->distance = DistanceManhattan(i->xy, i2->xy);
+	} else {
+		// pick a dest town, and see if it's big enough
+		t = AiFindRandomTown();
+		if (t == NULL || t->population < (uint32)(cargo == CT_FOOD ? 200 : 900))
+			return;
+
+		fr->to = t;
+		fr->distance = DistanceManhattan(i->xy, t->xy);
+	}
+}
+
+static void AiFindRandomPassengerRoute(FoundRoute *fr)
+{
+	uint32 r;
+	Town *source, *dest;
+
+	// initially error
+	fr->distance = -1;
+
+	r = Random();
+
+	fr->from = source = AiFindRandomTown();
+	if (source == NULL || source->population < 400)
+		return;
+
+	fr->to = dest = AiFindRandomTown();
+	if (dest == NULL || source == dest || dest->population < 400)
+		return;
+
+	fr->distance = DistanceManhattan(source->xy, dest->xy);
+}
+
+// Warn: depends on 'xy' being the first element in both Town and Industry
+#define GET_TOWN_OR_INDUSTRY_TILE(p) (((Town*)(p))->xy)
+
+static bool AiCheckIfRouteIsGood(Player *p, FoundRoute *fr, byte bitmask)
+{
+	TileIndex from_tile, to_tile;
+	Station *st;
+	int dist, cur;
+	uint same_station = 0;
+
+	// Make sure distance to closest station is < 37 pixels.
+	from_tile = GET_TOWN_OR_INDUSTRY_TILE(fr->from);
+	to_tile = GET_TOWN_OR_INDUSTRY_TILE(fr->to);
+
+	dist = 0xFFFF;
+	FOR_ALL_STATIONS(st) if (st->xy != 0 && st->owner == _current_player) {
+		cur = DistanceMax(from_tile, st->xy);
+		if (cur < dist) dist = cur;
+		cur = DistanceMax(to_tile, st->xy);
+		if (cur < dist) dist = cur;
+		if (to_tile == from_tile && st->xy == to_tile)
+		    same_station++;
+	}
+
+	// To prevent the AI from building ten busstations in the same town, do some calculations
+	//  For each road or airport station, we want 350 of population!
+	if ((bitmask == 2 || bitmask == 4) && same_station > 2 && ((Town *)(fr->from))->population < same_station * 350)
+	    return false;
+
+	if (dist != 0xFFFF && dist > 37)
+		return false;
+
+	if (p->ai.route_type_mask != 0 && !(p->ai.route_type_mask&bitmask) && !CHANCE16(1,5))
+		return false;
+
+	if (fr->cargo == CT_PASSENGERS || fr->cargo == CT_MAIL) {
+		if (((Town*)fr->from)->pct_pass_transported > 0x99 ||
+				((Town*)fr->to)->pct_pass_transported > 0x99)
+			return false;
+
+		// Make sure it has a reasonably good rating
+		if ( ((Town*)fr->from)->ratings[_current_player] < -100 ||
+				((Town*)fr->to)->ratings[_current_player] < -100)
+			return false;
+	} else {
+		Industry *i = (Industry*)fr->from;
+
+		if (i->pct_transported[fr->cargo != i->produced_cargo[0]] > 0x99 ||
+				i->total_production[fr->cargo != i->produced_cargo[0]] == 0)
+			return false;
+	}
+
+	p->ai.route_type_mask |= bitmask;
+	return true;
+}
+
+static byte AiGetDirectionBetweenTiles(TileIndex a, TileIndex b)
+{
+	byte i = (TileX(a) < TileX(b)) ? 1 : 0;
+	if (TileY(a) >= TileY(b)) i ^= 3;
+	return i;
+}
+
+static TileIndex AiGetPctTileBetween(TileIndex a, TileIndex b, byte pct)
+{
+	return TileXY(
+		TileX(a) + ((TileX(b) - TileX(a)) * pct >> 8),
+		TileY(a) + ((TileY(b) - TileY(a)) * pct >> 8)
+	);
+}
+
+static void AiWantLongIndustryRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+
+	i = 60;
+	for(;;) {
+		// look for one from the subsidy list
+		AiFindSubsidyIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 60, 90+1))
+			break;
+
+		// try a random one
+		AiFindRandomIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 60, 90+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	if (!AiCheckIfRouteIsGood(p, &fr, 1))
+		return;
+
+	// Fill the source field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 9;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.unk6 = 1;
+	p->ai.src.unk7 = 0;
+	p->ai.src.buildcmd_a = 0x24;
+	p->ai.src.buildcmd_b = 0xFF;
+	p->ai.src.direction = AiGetDirectionBetweenTiles(
+			p->ai.src.spec_tile,
+			p->ai.dst.spec_tile
+		);
+	p->ai.src.cargo = fr.cargo | 0x80;
+
+	// Fill the dest field
+
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 9;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.unk6 = 1;
+	p->ai.dst.unk7 = 0;
+	p->ai.dst.buildcmd_a = 0x34;
+	p->ai.dst.buildcmd_b = 0xFF;
+	p->ai.dst.direction = AiGetDirectionBetweenTiles(
+			p->ai.dst.spec_tile,
+			p->ai.src.spec_tile
+		);
+	p->ai.dst.cargo = fr.cargo;
+
+	// Fill middle field 1
+	p->ai.mid1.spec_tile = AiGetPctTileBetween(
+			p->ai.src.spec_tile,
+			p->ai.dst.spec_tile,
+			0x55
+		);
+	p->ai.mid1.use_tile = 0;
+	p->ai.mid1.rand_rng = 6;
+	p->ai.mid1.cur_building_rule = 0xFF;
+	p->ai.mid1.unk6 = 2;
+	p->ai.mid1.unk7 = 1;
+	p->ai.mid1.buildcmd_a = 0x30;
+	p->ai.mid1.buildcmd_b = 0xFF;
+	p->ai.mid1.direction = p->ai.src.direction;
+	p->ai.mid1.cargo = fr.cargo;
+
+	// Fill middle field 2
+	p->ai.mid2.spec_tile = AiGetPctTileBetween(
+			p->ai.src.spec_tile,
+			p->ai.dst.spec_tile,
+			0xAA
+		);
+	p->ai.mid2.use_tile = 0;
+	p->ai.mid2.rand_rng = 6;
+	p->ai.mid2.cur_building_rule = 0xFF;
+	p->ai.mid2.unk6 = 2;
+	p->ai.mid2.unk7 = 1;
+	p->ai.mid2.buildcmd_a = 0xFF;
+	p->ai.mid2.buildcmd_b = 0xFF;
+	p->ai.mid2.direction = p->ai.dst.direction;
+	p->ai.mid2.cargo = fr.cargo;
+
+	// Fill common fields
+	p->ai.cargo_type = fr.cargo;
+	p->ai.num_wagons = 3;
+	p->ai.build_kind = 2;
+	p->ai.num_build_rec = 4;
+	p->ai.num_loco_to_build = 2;
+	p->ai.num_want_fullload = 2;
+	p->ai.wagon_list[0] = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+
+	p->ai.state = AIS_BUILD_DEFAULT_RAIL_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantMediumIndustryRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+
+	i = 60;
+	for(;;) {
+
+		// look for one from the subsidy list
+		AiFindSubsidyIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 40, 60+1))
+			break;
+
+		// try a random one
+		AiFindRandomIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 40, 60+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	if (!AiCheckIfRouteIsGood(p, &fr, 1))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 9;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.unk6 = 1;
+	p->ai.src.unk7 = 0;
+	p->ai.src.buildcmd_a = 0x10;
+	p->ai.src.buildcmd_b = 0xFF;
+	p->ai.src.direction = AiGetDirectionBetweenTiles(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to)
+		);
+	p->ai.src.cargo = fr.cargo | 0x80;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 9;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.unk6 = 1;
+	p->ai.dst.unk7 = 0;
+	p->ai.dst.buildcmd_a = 0xFF;
+	p->ai.dst.buildcmd_b = 0xFF;
+	p->ai.dst.direction = AiGetDirectionBetweenTiles(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from)
+		);
+	p->ai.dst.cargo = fr.cargo;
+
+	// Fill common fields
+	p->ai.cargo_type = fr.cargo;
+	p->ai.num_wagons = 3;
+	p->ai.build_kind = 1;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 1;
+	p->ai.num_want_fullload = 1;
+	p->ai.wagon_list[0] = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+	p->ai.state = AIS_BUILD_DEFAULT_RAIL_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantShortIndustryRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+
+	i = 60;
+	for(;;) {
+
+		// look for one from the subsidy list
+		AiFindSubsidyIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 15, 40+1))
+			break;
+
+		// try a random one
+		AiFindRandomIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 15, 40+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	if (!AiCheckIfRouteIsGood(p, &fr, 1))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 9;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.unk6 = 1;
+	p->ai.src.unk7 = 0;
+	p->ai.src.buildcmd_a = 0x10;
+	p->ai.src.buildcmd_b = 0xFF;
+	p->ai.src.direction = AiGetDirectionBetweenTiles(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to)
+		);
+	p->ai.src.cargo = fr.cargo | 0x80;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 9;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.unk6 = 1;
+	p->ai.dst.unk7 = 0;
+	p->ai.dst.buildcmd_a = 0xFF;
+	p->ai.dst.buildcmd_b = 0xFF;
+	p->ai.dst.direction = AiGetDirectionBetweenTiles(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from)
+		);
+	p->ai.dst.cargo = fr.cargo;
+
+	// Fill common fields
+	p->ai.cargo_type = fr.cargo;
+	p->ai.num_wagons = 2;
+	p->ai.build_kind = 1;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 1;
+	p->ai.num_want_fullload = 1;
+	p->ai.wagon_list[0] = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+	p->ai.state = AIS_BUILD_DEFAULT_RAIL_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantMailRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+
+	i = 60;
+	for(;;) {
+
+		// look for one from the subsidy list
+		AiFindSubsidyPassengerRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 60, 110+1))
+			break;
+
+		// try a random one
+		AiFindRandomPassengerRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 60, 110+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	fr.cargo = CT_MAIL;
+	if (!AiCheckIfRouteIsGood(p, &fr, 1))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 7;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.unk6 = 1;
+	p->ai.src.unk7 = 0;
+	p->ai.src.buildcmd_a = 0x24;
+	p->ai.src.buildcmd_b = 0xFF;
+	p->ai.src.direction = AiGetDirectionBetweenTiles(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to)
+		);
+	p->ai.src.cargo = fr.cargo;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 7;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.unk6 = 1;
+	p->ai.dst.unk7 = 0;
+	p->ai.dst.buildcmd_a = 0x34;
+	p->ai.dst.buildcmd_b = 0xFF;
+	p->ai.dst.direction = AiGetDirectionBetweenTiles(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from)
+		);
+	p->ai.dst.cargo = fr.cargo;
+
+	// Fill middle field 1
+	p->ai.mid1.spec_tile = AiGetPctTileBetween(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to),
+			0x55
+		);
+	p->ai.mid1.use_tile = 0;
+	p->ai.mid1.rand_rng = 6;
+	p->ai.mid1.cur_building_rule = 0xFF;
+	p->ai.mid1.unk6 = 2;
+	p->ai.mid1.unk7 = 1;
+	p->ai.mid1.buildcmd_a = 0x30;
+	p->ai.mid1.buildcmd_b = 0xFF;
+	p->ai.mid1.direction = p->ai.src.direction;
+	p->ai.mid1.cargo = fr.cargo;
+
+	// Fill middle field 2
+	p->ai.mid2.spec_tile = AiGetPctTileBetween(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to),
+			0xAA
+		);
+	p->ai.mid2.use_tile = 0;
+	p->ai.mid2.rand_rng = 6;
+	p->ai.mid2.cur_building_rule = 0xFF;
+	p->ai.mid2.unk6 = 2;
+	p->ai.mid2.unk7 = 1;
+	p->ai.mid2.buildcmd_a = 0xFF;
+	p->ai.mid2.buildcmd_b = 0xFF;
+	p->ai.mid2.direction = p->ai.dst.direction;
+	p->ai.mid2.cargo = fr.cargo;
+
+	// Fill common fields
+	p->ai.cargo_type = fr.cargo;
+	p->ai.num_wagons = 3;
+	p->ai.build_kind = 2;
+	p->ai.num_build_rec = 4;
+	p->ai.num_loco_to_build = 2;
+	p->ai.num_want_fullload = 0;
+	p->ai.wagon_list[0] = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+	p->ai.state = AIS_BUILD_DEFAULT_RAIL_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantPassengerRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+
+	i = 60;
+	for(;;) {
+
+		// look for one from the subsidy list
+		AiFindSubsidyPassengerRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 0, 55+1))
+			break;
+
+		// try a random one
+		AiFindRandomPassengerRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 0, 55+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	fr.cargo = CT_PASSENGERS;
+	if (!AiCheckIfRouteIsGood(p, &fr, 1))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 7;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.unk6 = 1;
+	p->ai.src.unk7 = 0;
+	p->ai.src.buildcmd_a = 0x10;
+	p->ai.src.buildcmd_b = 0xFF;
+	p->ai.src.direction = AiGetDirectionBetweenTiles(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to)
+		);
+	p->ai.src.cargo = fr.cargo;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 7;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.unk6 = 1;
+	p->ai.dst.unk7 = 0;
+	p->ai.dst.buildcmd_a = 0xFF;
+	p->ai.dst.buildcmd_b = 0xFF;
+	p->ai.dst.direction = AiGetDirectionBetweenTiles(
+			GET_TOWN_OR_INDUSTRY_TILE(fr.to),
+			GET_TOWN_OR_INDUSTRY_TILE(fr.from)
+		);
+	p->ai.dst.cargo = fr.cargo;
+
+	// Fill common fields
+	p->ai.cargo_type = fr.cargo;
+	p->ai.num_wagons = 2;
+	p->ai.build_kind = 1;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 1;
+	p->ai.num_want_fullload = 0;
+	p->ai.wagon_list[0] = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+	p->ai.state = AIS_BUILD_DEFAULT_RAIL_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantTrainRoute(Player *p)
+{
+	uint16 r;
+	p->ai.railtype_to_use = p->max_railtype - 1;
+	r = (uint16)Random();
+
+	if (r > 0xD000) {
+		AiWantLongIndustryRoute(p);
+	} else if (r > 0x6000) {
+		AiWantMediumIndustryRoute(p);
+	} else if (r > 0x1000) {
+		AiWantShortIndustryRoute(p);
+	} else if (r > 0x800) {
+		AiWantPassengerRoute(p);
+	} else {
+		AiWantMailRoute(p);
+	}
+}
+
+static void AiWantLongRoadIndustryRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+
+	i = 60;
+	for(;;) {
+
+		// look for one from the subsidy list
+		AiFindSubsidyIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 35, 55+1))
+			break;
+
+		// try a random one
+		AiFindRandomIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 35, 55+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	if (!AiCheckIfRouteIsGood(p, &fr, 2))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 9;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.buildcmd_a = 1;
+	p->ai.src.direction = 0;
+	p->ai.src.cargo = fr.cargo | 0x80;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 9;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.buildcmd_a = 0xFF;
+	p->ai.dst.direction = 0;
+	p->ai.dst.cargo = fr.cargo;
+
+	// Fill common fields
+	p->ai.cargo_type = fr.cargo;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 5;
+	p->ai.num_want_fullload = 5;
+
+//	p->ai.loco_id = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+
+	p->ai.state = AIS_BUILD_DEFAULT_ROAD_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantMediumRoadIndustryRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+
+	i = 60;
+	for(;;) {
+
+		// look for one from the subsidy list
+		AiFindSubsidyIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 15, 40+1))
+			break;
+
+		// try a random one
+		AiFindRandomIndustryRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 15, 40+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	if (!AiCheckIfRouteIsGood(p, &fr, 2))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 9;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.buildcmd_a = 1;
+	p->ai.src.direction = 0;
+	p->ai.src.cargo = fr.cargo | 0x80;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 9;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.buildcmd_a = 0xFF;
+	p->ai.dst.direction = 0;
+	p->ai.dst.cargo = fr.cargo;
+
+	// Fill common fields
+	p->ai.cargo_type = fr.cargo;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 3;
+	p->ai.num_want_fullload = 3;
+
+//	p->ai.loco_id = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+
+	p->ai.state = AIS_BUILD_DEFAULT_ROAD_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantLongRoadPassengerRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+
+	i = 60;
+	for(;;) {
+
+		// look for one from the subsidy list
+		AiFindSubsidyPassengerRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 55, 180+1))
+			break;
+
+		// try a random one
+		AiFindRandomPassengerRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance, 55, 180+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	fr.cargo = CT_PASSENGERS;
+
+	if (!AiCheckIfRouteIsGood(p, &fr, 2))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 10;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.buildcmd_a = 1;
+	p->ai.src.direction = 0;
+	p->ai.src.cargo = CT_PASSENGERS;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 10;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.buildcmd_a = 0xFF;
+	p->ai.dst.direction = 0;
+	p->ai.dst.cargo = CT_PASSENGERS;
+
+	// Fill common fields
+	p->ai.cargo_type = CT_PASSENGERS;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 4;
+	p->ai.num_want_fullload = 0;
+
+//	p->ai.loco_id = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+
+	p->ai.state = AIS_BUILD_DEFAULT_ROAD_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantPassengerRouteInsideTown(Player *p)
+{
+	int i;
+	FoundRoute fr;
+	Town *t;
+
+	i = 60;
+	for(;;) {
+		// Find a town big enough
+		t = AiFindRandomTown();
+		if (t != NULL && t->population >= 700)
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	fr.cargo = CT_PASSENGERS;
+	fr.from = fr.to = t;
+
+	if (!AiCheckIfRouteIsGood(p, &fr, 2))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = t->xy;
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 10;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.buildcmd_a = 1;
+	p->ai.src.direction = 0;
+	p->ai.src.cargo = CT_PASSENGERS;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = t->xy;
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 10;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.buildcmd_a = 0xFF;
+	p->ai.dst.direction = 0;
+	p->ai.dst.cargo = CT_PASSENGERS;
+
+	// Fill common fields
+	p->ai.cargo_type = CT_PASSENGERS;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 2;
+	p->ai.num_want_fullload = 0;
+
+//	p->ai.loco_id = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+
+	p->ai.state = AIS_BUILD_DEFAULT_ROAD_BLOCKS;
+	p->ai.state_mode = -1;
+	p->ai.state_counter = 0;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantRoadRoute(Player *p)
+{
+	uint16 r = (uint16)Random();
+
+	if (r > 0x4000) {
+		AiWantLongRoadIndustryRoute(p);
+	} else if (r > 0x2000) {
+		AiWantMediumRoadIndustryRoute(p);
+	} else if (r > 0x1000) {
+		AiWantLongRoadPassengerRoute(p);
+	} else {
+		AiWantPassengerRouteInsideTown(p);
+	}
+
+}
+
+static void AiWantPassengerAircraftRoute(Player *p)
+{
+	FoundRoute fr;
+	int i;
+
+	i = 60;
+	for(;;) {
+
+		// look for one from the subsidy list
+		AiFindSubsidyPassengerRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance,0,95+1))
+			break;
+
+		// try a random one
+		AiFindRandomPassengerRoute(&fr);
+		if (IS_INT_INSIDE(fr.distance,0,95+1))
+			break;
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	fr.cargo = CT_PASSENGERS;
+	if (!AiCheckIfRouteIsGood(p, &fr, 4))
+		return;
+
+
+	// Fill the source field
+	p->ai.src.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.to);
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 12;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.cargo = fr.cargo;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = GET_TOWN_OR_INDUSTRY_TILE(fr.from);
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 12;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.cargo = fr.cargo;
+
+	// Fill common fields
+	p->ai.cargo_type = fr.cargo;
+	p->ai.build_kind = 0;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 1;
+	p->ai.num_want_fullload = 1;
+//	p->ai.loco_id = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+
+	p->ai.state = AIS_AIRPORT_STUFF;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantOilRigAircraftRoute(Player *p)
+{
+	int i;
+	FoundRoute fr;
+	Town *t;
+	Industry *in;
+
+	i = 60;
+	for(;;) {
+		// Find a town
+		t = AiFindRandomTown();
+		if (t != NULL) {
+			// Find a random oil rig industry
+			in = GetIndustry(RandomRange(_total_industries));
+			if (in != NULL && in->type == IT_OIL_RIG) {
+				if (DistanceManhattan(t->xy, in->xy) < 60)
+					break;
+			}
+		}
+
+		// only test 60 times
+		if (--i == 0)
+			return;
+	}
+
+	fr.cargo = CT_PASSENGERS;
+	fr.from = fr.to = t;
+
+	if (!AiCheckIfRouteIsGood(p, &fr, 4))
+		return;
+
+	// Fill the source field
+	p->ai.src.spec_tile = t->xy;
+	p->ai.src.use_tile = 0;
+	p->ai.src.rand_rng = 12;
+	p->ai.src.cur_building_rule = 0xFF;
+	p->ai.src.cargo = CT_PASSENGERS;
+
+	// Fill the dest field
+	p->ai.dst.spec_tile = in->xy;
+	p->ai.dst.use_tile = 0;
+	p->ai.dst.rand_rng = 5;
+	p->ai.dst.cur_building_rule = 0xFF;
+	p->ai.dst.cargo = CT_PASSENGERS;
+
+	// Fill common fields
+	p->ai.cargo_type = CT_PASSENGERS;
+	p->ai.build_kind = 1;
+	p->ai.num_build_rec = 2;
+	p->ai.num_loco_to_build = 1;
+	p->ai.num_want_fullload = 0;
+//	p->ai.loco_id = INVALID_VEHICLE;
+	p->ai.order_list_blocks[0] = 0;
+	p->ai.order_list_blocks[1] = 1;
+	p->ai.order_list_blocks[2] = 255;
+
+	p->ai.state = AIS_AIRPORT_STUFF;
+	p->ai.timeout_counter = 0;
+}
+
+static void AiWantAircraftRoute(Player *p)
+{
+	uint16 r = (uint16)Random();
+
+	if (r >= 0x2AAA || _date < 0x3912) {
+		AiWantPassengerAircraftRoute(p);
+	} else {
+		AiWantOilRigAircraftRoute(p);
+	}
+}
+
+static void AiWantShipRoute(Player *p)
+{
+	// XXX
+//	error("AiWaitShipRoute");
+}
+
+
+
+static void AiStateWantNewRoute(Player *p)
+{
+	uint16 r;
+	int i;
+
+	if (p->player_money < AiGetBasePrice(p) * 500) {
+		p->ai.state = AIS_0;
+		return;
+	}
+
+	i = 200;
+	for(;;) {
+		r = (uint16)Random();
+
+		if (_patches.ai_disable_veh_train && _patches.ai_disable_veh_roadveh &&
+			_patches.ai_disable_veh_aircraft && _patches.ai_disable_veh_ship)
+			return;
+
+		if (r < 0x7626) {
+			if (_patches.ai_disable_veh_train) continue;
+			AiWantTrainRoute(p);
+		} else if (r < 0xC4EA) {
+			if (_patches.ai_disable_veh_roadveh) continue;
+			AiWantRoadRoute(p);
+		} else if (r < 0xD89B) {
+			if (_patches.ai_disable_veh_aircraft) continue;
+			AiWantAircraftRoute(p);
+		} else {
+			if (_patches.ai_disable_veh_ship) continue;
+			AiWantShipRoute(p);
+		}
+
+		// got a route?
+		if (p->ai.state != AIS_WANT_NEW_ROUTE)
+			break;
+
+		// time out?
+		if (--i == 0) {
+			if (++p->ai.state_counter == 556) p->ai.state = AIS_0;
+			break;
+		}
+	}
+}
+
+static bool AiCheckTrackResources(TileIndex tile, const AiDefaultBlockData *p, byte cargo)
+{
+	uint values[NUM_CARGO];
+	int w,h;
+	int rad;
+
+	for(;p->mode != 4;p++) if (p->mode == 1) {
+		TileIndex tile2 = TILE_ADD(tile, ToTileIndexDiff(p->tileoffs));
+
+		w = ((p->attr>>1) & 7);
+		h = ((p->attr>>4) & 7);
+		if (p->attr&1) intswap(w, h);
+
+
+		if (_patches.modified_catchment) {
+			rad = CA_TRAIN;
+		} else {
+			rad = 4;
+		}
+
+		if (cargo & 0x80) {
+			GetProductionAroundTiles(values, tile2, w, h, rad);
+			return values[cargo & 0x7F] != 0;
+		} else {
+			GetAcceptanceAroundTiles(values, tile2, w, h, rad);
+			if (!(values[cargo] & ~7))
+				return false;
+			if (cargo != CT_MAIL)
+				return true;
+			return !!((values[cargo]>>1) & ~7);
+		}
+	}
+
+	return true;
+}
+
+static int32 AiDoBuildDefaultRailTrack(TileIndex tile, const AiDefaultBlockData *p, byte flag)
+{
+	int32 ret;
+	int32 total_cost = 0;
+	Town *t = NULL;
+	int rating = 0;
+	int i,j,k;
+
+	for(;;) {
+		// This will seldomly overflow for valid reasons. Mask it to be on the safe side.
+		uint c = TILE_MASK(tile + ToTileIndexDiff(p->tileoffs));
+
+		_cleared_town = NULL;
+
+		if (p->mode < 2) {
+			if (p->mode == 0) {
+				// Depot
+				ret = DoCommandByTile(c, _cur_ai_player->ai.railtype_to_use, p->attr, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_TRAIN_DEPOT);
+			} else {
+				// Station
+				ret = DoCommandByTile(c, (p->attr&1) | (p->attr>>4)<<8 | (p->attr>>1&7)<<16, _cur_ai_player->ai.railtype_to_use, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_RAILROAD_STATION);
+			}
+
+			if (CmdFailed(ret)) return CMD_ERROR;
+			total_cost += ret;
+
+clear_town_stuff:;
+			if (_cleared_town != NULL) {
+				if (t != NULL && t != _cleared_town)
+					return CMD_ERROR;
+				t = _cleared_town;
+				rating += _cleared_town_rating;
+			}
+		} else if (p->mode == 2) {
+			// Rail
+			if (IsTileType(c, MP_RAILWAY))
+				return CMD_ERROR;
+
+			j = p->attr;
+			k = 0;
+
+			// Build the rail
+			for(i=0; i!=6; i++,j>>=1) {
+				if (j&1) {
+					k = i;
+					ret = DoCommandByTile(c, _cur_ai_player->ai.railtype_to_use, i, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_SINGLE_RAIL);
+					if (CmdFailed(ret)) return CMD_ERROR;
+					total_cost += ret;
+				}
+			}
+
+			/* signals too? */
+			if (j&3) {
+				// Can't build signals on a road.
+				if (IsTileType(c, MP_STREET)) return CMD_ERROR;
+
+				if (flag & DC_EXEC) {
+					j = 4 - j;
+					do {
+						ret = DoCommandByTile(c, k, 0, flag, CMD_BUILD_SIGNALS);
+					} while (--j);
+				} else {
+					ret = _price.build_signals;
+				}
+				if (CmdFailed(ret)) return CMD_ERROR;
+				total_cost += ret;
+			}
+		} else if (p->mode == 3) {
+			//Clear stuff and then build single rail.
+			if (GetTileSlope(c,NULL) != 0)
+				return CMD_ERROR;
+			ret = DoCommandByTile(c, 0, 0, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_LANDSCAPE_CLEAR);
+			if (CmdFailed(ret)) return CMD_ERROR;
+			total_cost += ret + _price.build_rail;
+
+			if (flag & DC_EXEC) {
+				DoCommandByTile(c, _cur_ai_player->ai.railtype_to_use, p->attr&1, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_SINGLE_RAIL);
+			}
+
+			goto clear_town_stuff;
+		} else {
+			// Unk
+			break;
+		}
+
+		p++;
+	}
+
+	if (!(flag & DC_EXEC)) {
+		if (t != NULL && rating > t->ratings[_current_player]) {
+			return CMD_ERROR;
+		}
+	}
+
+	return total_cost;
+}
+
+// Returns rule and cost
+static int AiBuildDefaultRailTrack(TileIndex tile, byte p0, byte p1, byte p2, byte p3, byte dir, byte cargo, int32 *cost)
+{
+	int i;
+	const AiDefaultRailBlock *p;
+
+	for(i=0; (p = _default_rail_track_data[i]) != NULL; i++) {
+		if (p->p0 == p0 && p->p1 == p1 && p->p2 == p2 && p->p3 == p3 &&
+				(p->dir == 0xFF || p->dir == dir || ((p->dir-1)&3) == dir)) {
+			*cost = AiDoBuildDefaultRailTrack(tile, p->data, DC_NO_TOWN_RATING);
+			if (*cost != CMD_ERROR && AiCheckTrackResources(tile, p->data, cargo))
+				return i;
+		}
+	}
+
+	return -1;
+}
+
+static const byte _terraform_up_flags[] = {
+	14, 13, 12, 11,
+	10, 9, 8, 7,
+	6, 5, 4, 3,
+	2, 1, 0, 1,
+	2, 1, 4, 1,
+	2, 1, 8, 1,
+	2, 1, 4, 2,
+	2, 1
+};
+
+static const byte _terraform_down_flags[] = {
+	1, 2, 3, 4,
+	5, 6, 1, 8,
+	9, 10, 8, 12,
+	4, 2, 0, 0,
+	1, 2, 3, 4,
+	5, 6, 2, 8,
+	9, 10, 1, 12,
+	8, 4
+};
+
+static void AiDoTerraformLand(TileIndex tile, int dir, int unk, int mode)
+{
+	byte old_player;
+	uint32 r;
+	uint slope;
+	uint h;
+
+	old_player = _current_player;
+	_current_player = OWNER_NONE;
+
+	r = Random();
+
+	unk &= (int)r;
+
+	do {
+		tile = TILE_MASK(tile + TileOffsByDir(dir));
+
+		r >>= 2;
+		if (r&2) {
+			dir++;
+			if (r&1)
+				dir -= 2;
+		}
+		dir &= 3;
+	} while (--unk >= 0);
+
+	slope = GetTileSlope(tile, &h);
+
+	if (slope != 0) {
+		if (mode > 0 || (mode == 0 && !(r&0xC))) {
+			// Terraform up
+			DoCommandByTile(tile, _terraform_up_flags[slope-1], 1,
+				DC_EXEC | DC_AUTO | DC_NO_WATER, CMD_TERRAFORM_LAND);
+		} else if (h != 0) {
+			// Terraform down
+			DoCommandByTile(tile, _terraform_down_flags[slope-1], 0,
+				DC_EXEC | DC_AUTO | DC_NO_WATER, CMD_TERRAFORM_LAND);
+		}
+	}
+
+	_current_player = old_player;
+}
+
+static void AiStateBuildDefaultRailBlocks(Player *p)
+{
+	int i, j;
+	AiBuildRec *aib;
+	int rule;
+	int32 cost;
+
+	// time out?
+	if (++p->ai.timeout_counter == 1388) {
+		p->ai.state = AIS_DELETE_RAIL_BLOCKS;
+		return;
+	}
+
+	// do the following 8 times
+	i = 8;
+	do {
+		// check if we can build the default track
+		aib = &p->ai.src;
+		j = p->ai.num_build_rec;
+		do {
+			// this item has already been built?
+			if (aib->cur_building_rule != 255)
+				continue;
+
+			// adjust the coordinate randomly,
+			// to make sure that we find a position.
+			aib->use_tile = AdjustTileCoordRandomly(aib->spec_tile, aib->rand_rng);
+
+			// check if the track can be build there.
+			rule = AiBuildDefaultRailTrack(aib->use_tile,
+				p->ai.build_kind, p->ai.num_wagons,
+				aib->unk6, aib->unk7,
+				aib->direction, aib->cargo, &cost);
+
+			if (rule == -1) {
+				// cannot build, terraform after a while
+				if (p->ai.state_counter >= 600) {
+					AiDoTerraformLand(aib->use_tile, Random()&3, 3, (int8)p->ai.state_mode);
+				}
+				// also try the other terraform direction
+				if (++p->ai.state_counter >= 1000) {
+					p->ai.state_counter = 0;
+					p->ai.state_mode = -p->ai.state_mode;
+				}
+			} else if (CheckPlayerHasMoney(cost)) {
+				int32 r;
+				// player has money, build it.
+				aib->cur_building_rule = rule;
+
+				r = AiDoBuildDefaultRailTrack(
+					aib->use_tile,
+					_default_rail_track_data[rule]->data,
+					DC_EXEC | DC_NO_TOWN_RATING
+				);
+				assert(r != CMD_ERROR);
+			}
+		} while (++aib,--j);
+	} while (--i);
+
+	// check if we're done with all of them
+	aib = &p->ai.src;
+	j = p->ai.num_build_rec;
+	do {
+		if (aib->cur_building_rule == 255)
+			return;
+	} while (++aib,--j);
+
+	// yep, all are done. switch state to the rail building state.
+	p->ai.state = AIS_BUILD_RAIL;
+	p->ai.state_mode = 255;
+}
+
+static TileIndex AiGetEdgeOfDefaultRailBlock(byte rule, TileIndex tile, byte cmd, int *dir)
+{
+	const AiDefaultBlockData *p = _default_rail_track_data[rule]->data;
+
+	while (p->mode != 3 || !((--cmd) & 0x80)) p++;
+
+	return tile + ToTileIndexDiff(p->tileoffs) - TileOffsByDir(*dir = p->attr);
+}
+
+typedef struct AiRailPathFindData {
+	TileIndex tile;
+	TileIndex tile2;
+	int count;
+	bool flag;
+} AiRailPathFindData;
+
+static bool AiEnumFollowTrack(TileIndex tile, AiRailPathFindData *a, int track, uint length, byte *state)
+{
+	if (a->flag)
+		return true;
+
+	if (length > 20 || tile == a->tile) {
+		a->flag = true;
+		return true;
+	}
+
+	if (DistanceMax(tile, a->tile2) < 4)
+		a->count++;
+
+	return false;
+}
+
+static bool AiDoFollowTrack(Player *p)
+{
+	AiRailPathFindData arpfd;
+	arpfd.tile = p->ai.start_tile_a;
+	arpfd.tile2 = p->ai.cur_tile_a;
+	arpfd.flag = false;
+	arpfd.count = 0;
+	FollowTrack(p->ai.cur_tile_a + TileOffsByDir(p->ai.cur_dir_a), 0x2000 | TRANSPORT_RAIL, p->ai.cur_dir_a^2,
+		(TPFEnumProc*)AiEnumFollowTrack, NULL, &arpfd);
+	return arpfd.count > 8;
+}
+
+typedef struct AiRailFinder {
+	TileIndex final_tile;
+	byte final_dir;
+	byte depth;
+	byte recursive_mode;
+	byte cur_best_dir;
+	byte best_dir;
+	byte cur_best_depth;
+	byte best_depth;
+	uint cur_best_dist;
+	const byte *best_ptr;
+	uint best_dist;
+	TileIndex cur_best_tile, best_tile;
+	TileIndex bridge_end_tile;
+	Player *player;
+	TileInfo ti;
+} AiRailFinder;
+
+static const byte _ai_table_15[4][8] = {
+	{0, 0, 4, 3, 3, 1, 128+0, 64},
+	{1, 1, 2, 0, 4, 2, 128+1, 65},
+	{0, 2, 2, 3, 5, 1, 128+2, 66},
+	{1, 3, 5, 0, 3, 2, 128+3, 67}
+};
+
+static const byte _dir_table_1[] = {3, 9, 12, 6};
+static const byte _dir_table_2[] = {12, 6, 3, 9};
+
+
+static bool AiIsTileBanned(Player *p, TileIndex tile, byte val) {
+	int i;
+
+	for(i=0; i!=p->ai.banned_tile_count; i++)
+		if (p->ai.banned_tiles[i] == tile &&
+				p->ai.banned_val[i] == val)
+					return true;
+	return false;
+}
+
+static void AiBanTile(Player *p, TileIndex tile, byte val) {
+	int i;
+
+	for(i=lengthof(p->ai.banned_tiles)-1; i!=0; i--) {
+		p->ai.banned_tiles[i] = p->ai.banned_tiles[i-1];
+		p->ai.banned_val[i] = p->ai.banned_val[i-1];
+	}
+
+	p->ai.banned_tiles[0] = tile;
+	p->ai.banned_val[0] = val;
+
+	if (p->ai.banned_tile_count != lengthof(p->ai.banned_tiles))
+		p->ai.banned_tile_count++;
+}
+
+static void AiBuildRailRecursive(AiRailFinder *arf, TileIndex tile, int dir);
+
+static bool AiCheckRailPathBetter(AiRailFinder *arf, const byte *p)
+{
+	bool better = false;
+
+	if (arf->recursive_mode < 1) {
+		// Mode is 0. This means destination has not been found yet.
+		// If the found path is shorter than the current one, remember it.
+		if (arf->cur_best_dist < arf->best_dist) {
+			arf->best_dir = arf->cur_best_dir;
+			arf->best_dist = arf->cur_best_dist;
+			arf->best_ptr = p;
+			arf->best_tile = arf->cur_best_tile;
+			better = true;
+		}
+	} else if (arf->recursive_mode > 1) {
+		// Mode is 2.
+		if (arf->best_dist != 0 || arf->cur_best_depth < arf->best_depth) {
+			arf->best_depth = arf->cur_best_depth;
+			arf->best_dist = 0;
+			arf->best_ptr = p;
+			arf->best_tile = 0;
+			better = true;
+		}
+	}
+	arf->recursive_mode = 0;
+	arf->cur_best_dist = (uint)-1;
+	arf->cur_best_depth = 0xff;
+
+	return better;
+}
+
+static inline void AiCheckBuildRailBridgeHere(AiRailFinder *arf, TileIndex tile, const byte *p)
+{
+	TileIndex tile_new;
+	bool flag;
+
+	int dir2 = p[0] & 3;
+
+	FindLandscapeHeightByTile(&arf->ti, tile);
+
+	if (arf->ti.tileh == _dir_table_1[dir2] || (arf->ti.tileh==0 && arf->ti.z!=0)) {
+		tile_new = tile;
+		// Allow bridges directly over bottom tiles
+		flag = arf->ti.z == 0;
+		for(;;) {
+			if ((TileIndexDiff)tile_new < -TileOffsByDir(dir2)) return; // Wraping around map, no bridge possible!
+			tile_new = TILE_MASK(tile_new + TileOffsByDir(dir2));
+			FindLandscapeHeightByTile(&arf->ti, tile_new);
+			if (arf->ti.tileh != 0 || arf->ti.type == MP_CLEAR || arf->ti.type == MP_TREES) {
+				if (!flag) return;
+				break;
+			}
+			if (arf->ti.type != MP_WATER && arf->ti.type != MP_RAILWAY && arf->ti.type != MP_STREET)
+				return;
+			flag = true;
+		}
+
+		// Is building a (rail)bridge possible at this place (type doesn't matter)?
+		if (CmdFailed(DoCommandByTile(tile_new, tile, 0 | arf->player->ai.railtype_to_use << 8,
+			DC_AUTO, CMD_BUILD_BRIDGE)) )
+				return;
+		AiBuildRailRecursive(arf, tile_new, dir2);
+
+		// At the bottom depth, check if the new path is better than the old one.
+		if (arf->depth == 1) {
+			if (AiCheckRailPathBetter(arf, p))
+				arf->bridge_end_tile = tile_new;
+		}
+	}
+}
+
+static inline void AiCheckBuildRailTunnelHere(AiRailFinder *arf, TileIndex tile, const byte *p)
+{
+	FindLandscapeHeightByTile(&arf->ti, tile);
+
+	if (arf->ti.tileh == _dir_table_2[p[0]&3] && arf->ti.z!=0) {
+		int32 cost = DoCommandByTile(tile, arf->player->ai.railtype_to_use, 0, DC_AUTO, CMD_BUILD_TUNNEL);
+
+		if (!CmdFailed(cost) && cost <= (arf->player->player_money>>4)) {
+			AiBuildRailRecursive(arf, _build_tunnel_endtile, p[0]&3);
+			if (arf->depth == 1) {
+				AiCheckRailPathBetter(arf, p);
+			}
+		}
+	}
+}
+
+
+static void AiBuildRailRecursive(AiRailFinder *arf, TileIndex tile, int dir)
+{
+	const byte *p;
+
+	tile = TILE_MASK(tile + TileOffsByDir(dir));
+
+	// Reached destination?
+	if (tile == arf->final_tile) {
+		if (arf->final_dir != (dir^2)) {
+			if (arf->recursive_mode != 2)
+				arf->recursive_mode = 1;
+		} else if (arf->recursive_mode != 2) {
+			arf->recursive_mode = 2;
+			arf->cur_best_depth = arf->depth;
+		} else {
+			if (arf->depth < arf->cur_best_depth)
+				arf->cur_best_depth = arf->depth;
+		}
+		return;
+	}
+
+	// Depth too deep?
+	if (arf->depth >= 4) {
+		uint dist = DistanceMaxPlusManhattan(tile, arf->final_tile);
+		if (dist < arf->cur_best_dist) {
+			// Store the tile that is closest to the final position.
+			arf->cur_best_depth = arf->depth;
+			arf->cur_best_dist = dist;
+			arf->cur_best_tile = tile;
+			arf->cur_best_dir = dir;
+		}
+		return;
+	}
+
+	// Increase recursion depth
+	arf->depth++;
+
+	// Grab pointer to list of stuff that is possible to build
+	p = _ai_table_15[dir];
+
+	// Try to build a single rail in all directions.
+	FindLandscapeHeightByTile(&arf->ti, tile);
+	if (arf->ti.z == 0) {
+		p += 6;
+	} else {
+		do {
+			// Make sure the tile is not in the list of banned tiles and that a rail can be built here.
+			if (!AiIsTileBanned(arf->player, tile, p[0]) &&
+					!CmdFailed(DoCommandByTile(tile, arf->player->ai.railtype_to_use, p[0], DC_AUTO | DC_NO_WATER | DC_NO_RAIL_OVERLAP, CMD_BUILD_SINGLE_RAIL))) {
+				AiBuildRailRecursive(arf, tile, p[1]);
+			}
+
+			// At the bottom depth?
+			if (arf->depth == 1) {
+				AiCheckRailPathBetter(arf, p);
+			}
+
+			p += 2;
+		} while (!(p[0]&0x80));
+	}
+
+	AiCheckBuildRailBridgeHere(arf, tile, p);
+	AiCheckBuildRailTunnelHere(arf, tile, p+1);
+
+	arf->depth--;
+}
+
+
+static const byte _dir_table_3[]= {0x25, 0x2A, 0x19, 0x16};
+
+static void AiBuildRailConstruct(Player *p)
+{
+	AiRailFinder arf;
+	int i;
+
+	// Check too much lookahead?
+	if (AiDoFollowTrack(p)) {
+		p->ai.state_counter = (Random()&0xE)+6; // Destruct this amount of blocks
+		p->ai.state_mode = 1; // Start destruct
+
+		// Ban this tile and don't reach it for a while.
+		AiBanTile(p, p->ai.cur_tile_a, FindFirstBit(GetRailTrackStatus(p->ai.cur_tile_a)));
+		return;
+	}
+
+	// Setup recursive finder and call it.
+	arf.player = p;
+	arf.final_tile = p->ai.cur_tile_b;
+	arf.final_dir = p->ai.cur_dir_b;
+	arf.depth = 0;
+	arf.recursive_mode = 0;
+	arf.best_ptr = NULL;
+	arf.cur_best_dist = (uint)-1;
+	arf.cur_best_depth = 0xff;
+	arf.best_dist = (uint)-1;
+	arf.best_depth = 0xff;
+	arf.cur_best_tile = 0;
+	arf.best_tile = 0;
+	AiBuildRailRecursive(&arf, p->ai.cur_tile_a, p->ai.cur_dir_a);
+
+	// Reached destination?
+	if (arf.recursive_mode == 2 && arf.cur_best_depth == 0) {
+		p->ai.state_mode = 255;
+		return;
+	}
+
+	// Didn't find anything to build?
+	if (arf.best_ptr == NULL) {
+		// Terraform some
+		for(i=0; i!=5; i++)
+			AiDoTerraformLand(p->ai.cur_tile_a, p->ai.cur_dir_a, 3, 0);
+
+		if (++p->ai.state_counter == 21) {
+			p->ai.state_counter = 40;
+			p->ai.state_mode = 1;
+
+			// Ban this tile
+			AiBanTile(p, p->ai.cur_tile_a, FindFirstBit(GetRailTrackStatus(p->ai.cur_tile_a)));
+		}
+		return;
+	}
+
+	p->ai.cur_tile_a += TileOffsByDir(p->ai.cur_dir_a);
+
+	if (arf.best_ptr[0]&0x80) {
+		int i;
+		int32 bridge_len = GetBridgeLength(arf.bridge_end_tile, p->ai.cur_tile_a);
+
+		/*	Figure out what (rail)bridge type to build
+				start with best bridge, then go down to worse and worse bridges
+				unnecessary to check for worse bridge (i=0), since AI will always build that.
+				AI is so fucked up that fixing this small thing will probably not solve a thing
+		*/
+		for (i = MAX_BRIDGES - 1; i != 0; i--) {
+			if (CheckBridge_Stuff(i, bridge_len)) {
+				int32 cost = DoCommandByTile(arf.bridge_end_tile, p->ai.cur_tile_a, i | (p->ai.railtype_to_use << 8), DC_AUTO, CMD_BUILD_BRIDGE);
+				if (!CmdFailed(cost) && cost < (p->player_money >> 5))
+					break;
+			}
+		}
+
+		// Build it
+		DoCommandByTile(arf.bridge_end_tile, p->ai.cur_tile_a, i | (p->ai.railtype_to_use << 8), DC_AUTO | DC_EXEC, CMD_BUILD_BRIDGE);
+
+		p->ai.cur_tile_a = arf.bridge_end_tile;
+		p->ai.state_counter = 0;
+	} else if (arf.best_ptr[0]&0x40) {
+		// tunnel
+		DoCommandByTile(p->ai.cur_tile_a, p->ai.railtype_to_use, 0, DC_AUTO | DC_EXEC, CMD_BUILD_TUNNEL);
+		p->ai.cur_tile_a = _build_tunnel_endtile;
+		p->ai.state_counter = 0;
+	} else {
+		// rail
+		p->ai.cur_dir_a = arf.best_ptr[1];
+		DoCommandByTile(p->ai.cur_tile_a, p->ai.railtype_to_use, arf.best_ptr[0],
+			DC_EXEC | DC_AUTO | DC_NO_WATER | DC_NO_RAIL_OVERLAP, CMD_BUILD_SINGLE_RAIL);
+		p->ai.state_counter = 0;
+	}
+
+	if (arf.best_tile != 0) {
+		for(i=0; i!=2; i++)
+			AiDoTerraformLand(arf.best_tile, arf.best_dir, 3, 0);
+	}
+}
+
+static bool AiRemoveTileAndGoForward(Player *p)
+{
+	byte b;
+	int bit;
+	const byte *ptr;
+	TileIndex tile = p->ai.cur_tile_a;
+	int offs;
+	TileIndex tilenew;
+
+	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
+		if (!(_m[tile].m5 & 0x80)) {
+			// Clear the tunnel and continue at the other side of it.
+			if (CmdFailed(DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR)) )
+				return false;
+			p->ai.cur_tile_a = TILE_MASK(_build_tunnel_endtile - TileOffsByDir(p->ai.cur_dir_a));
+			return true;
+		}
+
+		if (!(_m[tile].m5 & 0x40)) {
+
+			// Check if the bridge points in the right direction.
+			// This is not really needed the first place AiRemoveTileAndGoForward is called.
+			if ((_m[tile].m5&1) != (p->ai.cur_dir_a&1))
+				return false;
+
+			// Find other side of bridge.
+			offs = TileOffsByDir(p->ai.cur_dir_a);
+			do {
+				tile = TILE_MASK(tile - offs);
+			} while (_m[tile].m5 & 0x40);
+
+			tilenew = TILE_MASK(tile - offs);
+			// And clear the bridge.
+			if (CmdFailed(DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR)) )
+				return false;
+			p->ai.cur_tile_a = tilenew;
+			return true;
+		}
+	}
+
+	// Find the railtype at the position. Quit if no rail there.
+	b = GetRailTrackStatus(tile) & _dir_table_3[p->ai.cur_dir_a];
+	if (b == 0)
+		return false;
+
+	// Convert into a bit position that CMD_REMOVE_SINGLE_RAIL expects.
+	bit = FindFirstBit(b);
+
+	// Then remove and signals if there are any.
+	if (IsTileType(tile, MP_RAILWAY) &&
+			(_m[tile].m5&0xC0) == 0x40) {
+		DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_REMOVE_SIGNALS);
+	}
+
+	// And also remove the rail.
+	if (CmdFailed(DoCommandByTile(tile, 0, bit, DC_EXEC, CMD_REMOVE_SINGLE_RAIL)) )
+		return false;
+
+	// Find the direction at the other edge of the rail.
+	ptr = _ai_table_15[p->ai.cur_dir_a^2];
+	while (ptr[0] != bit) ptr+=2;
+	p->ai.cur_dir_a = ptr[1] ^ 2;
+
+	// And then also switch tile.
+	p->ai.cur_tile_a = TILE_MASK(p->ai.cur_tile_a - TileOffsByDir(p->ai.cur_dir_a));
+
+	return true;
+}
+
+
+static void AiBuildRailDestruct(Player *p)
+{
+	// Decrease timeout.
+	if (!--p->ai.state_counter) {
+		p->ai.state_mode = 2;
+		p->ai.state_counter = 0;
+	}
+
+	// Don't do anything if the destination is already reached.
+	if (p->ai.cur_tile_a == p->ai.start_tile_a)
+		return;
+
+	AiRemoveTileAndGoForward(p);
+}
+
+
+static void AiBuildRail(Player *p)
+{
+	int i;
+
+	if (p->ai.state_mode < 1) {
+		// Construct mode, build new rail.
+		AiBuildRailConstruct(p);
+	} else if (p->ai.state_mode == 1) {
+
+		// Destruct mode, destroy the rail currently built.
+		AiBuildRailDestruct(p);
+	} else if (p->ai.state_mode == 2) {
+
+		// Terraform some and then try building again.
+		for(i=0; i!=4; i++)
+			AiDoTerraformLand(p->ai.cur_tile_a, p->ai.cur_dir_a, 3, 0);
+
+		if (++p->ai.state_counter == 4) {
+			p->ai.state_counter = 0;
+			p->ai.state_mode = 0;
+		}
+	}
+}
+
+static void AiStateBuildRail(Player *p)
+{
+	int num;
+	AiBuildRec *aib;
+	byte cmd;
+	TileIndex tile;
+	int dir;
+
+	// time out?
+	if (++p->ai.timeout_counter == 1388) {
+		p->ai.state = AIS_DELETE_RAIL_BLOCKS;
+		return;
+	}
+
+	// Currently building a rail between two points?
+	if (p->ai.state_mode != 255) {
+		AiBuildRail(p);
+
+		// Alternate between edges
+		swap_tile(&p->ai.start_tile_a, &p->ai.start_tile_b);
+		swap_tile(&p->ai.cur_tile_a, &p->ai.cur_tile_b);
+		swap_byte(&p->ai.start_dir_a, &p->ai.start_dir_b);
+		swap_byte(&p->ai.cur_dir_a, &p->ai.cur_dir_b);
+		return;
+	}
+
+	// Now, find two new points to build between
+	num = p->ai.num_build_rec;
+	aib = &p->ai.src;
+
+	for(;;) {
+		cmd = aib->buildcmd_a;
+		aib->buildcmd_a = 255;
+		if (cmd != 255) break;
+
+		cmd = aib->buildcmd_b;
+		aib->buildcmd_b = 255;
+		if (cmd != 255) break;
+
+		aib++;
+		if (--num == 0) {
+			p->ai.state = AIS_BUILD_RAIL_VEH;
+			p->ai.state_counter = 0; // timeout
+			return;
+		}
+	}
+
+	// Find first edge to build from.
+	tile = AiGetEdgeOfDefaultRailBlock(aib->cur_building_rule, aib->use_tile, cmd&3, &dir);
+	p->ai.start_tile_a = tile;
+	p->ai.cur_tile_a = tile;
+	p->ai.start_dir_a = dir;
+	p->ai.cur_dir_a = dir;
+	DoCommandByTile(TILE_MASK(tile + TileOffsByDir(dir)), 0, (dir&1)?1:0, DC_EXEC, CMD_REMOVE_SINGLE_RAIL);
+
+	assert(TILE_MASK(tile) != 0xFF00);
+
+	// Find second edge to build to
+	aib = (&p->ai.src) + ((cmd >> 4)&0xF);
+	tile = AiGetEdgeOfDefaultRailBlock(aib->cur_building_rule, aib->use_tile, (cmd>>2)&3, &dir);
+	p->ai.start_tile_b = tile;
+	p->ai.cur_tile_b = tile;
+	p->ai.start_dir_b = dir;
+	p->ai.cur_dir_b = dir;
+	DoCommandByTile(TILE_MASK(tile + TileOffsByDir(dir)), 0, (dir&1)?1:0, DC_EXEC, CMD_REMOVE_SINGLE_RAIL);
+
+	assert(TILE_MASK(tile) != 0xFF00);
+
+	// And setup state.
+	p->ai.state_mode = 2;
+	p->ai.state_counter = 0;
+	p->ai.banned_tile_count = 0;
+}
+
+static int AiGetStationIdByDef(TileIndex tile, int id)
+{
+	const AiDefaultBlockData *p = _default_rail_track_data[id]->data;
+	while (p->mode != 1) p++;
+	return _m[TILE_ADD(tile, ToTileIndexDiff(p->tileoffs))].m2;
+}
+
+static void AiStateBuildRailVeh(Player *p)
+{
+	const AiDefaultBlockData *ptr;
+	TileIndex tile;
+	int i, veh;
+	int cargo;
+	int32 cost;
+	Vehicle *v;
+	uint loco_id;
+
+	ptr = _default_rail_track_data[p->ai.src.cur_building_rule]->data;
+	while (ptr->mode != 0) {	ptr++; }
+
+	tile = TILE_ADD(p->ai.src.use_tile, ToTileIndexDiff(ptr->tileoffs));
+
+	cargo = p->ai.cargo_type;
+	for(i=0;;) {
+		if (p->ai.wagon_list[i] == INVALID_VEHICLE) {
+			veh = _cargoc.ai_railwagon[p->ai.railtype_to_use][cargo];
+			cost = DoCommandByTile(tile, veh, 0, DC_EXEC, CMD_BUILD_RAIL_VEHICLE);
+			if (CmdFailed(cost)) goto handle_nocash;
+			p->ai.wagon_list[i] = _new_wagon_id;
+			p->ai.wagon_list[i+1] = INVALID_VEHICLE;
+			return;
+		}
+		if (cargo == CT_MAIL)
+			cargo = CT_PASSENGERS;
+		if (++i == p->ai.num_wagons * 2 - 1)
+			break;
+	}
+
+	// Which locomotive to build?
+	veh = AiChooseTrainToBuild(p->ai.railtype_to_use, p->player_money, (cargo!=CT_PASSENGERS)?1:0, tile);
+	if (veh == -1) {
+handle_nocash:
+		// after a while, if AI still doesn't have cash, get out of this block by selling the wagons.
+		if (++p->ai.state_counter == 1000) {
+			for(i=0; p->ai.wagon_list[i] != INVALID_VEHICLE; i++) {
+				cost = DoCommandByTile(tile, p->ai.wagon_list[i], 0, DC_EXEC, CMD_SELL_RAIL_WAGON);
+				assert(!CmdFailed(cost));
+			}
+			p->ai.state =	AIS_0;
+		}
+		return;
+	}
+
+	// Try to build the locomotive
+	cost = DoCommandByTile(tile, veh, 0, DC_EXEC, CMD_BUILD_RAIL_VEHICLE);
+	assert(!CmdFailed(cost));
+	loco_id = _new_train_id;
+
+	// Sell a vehicle if the train is double headed.
+	v = GetVehicle(loco_id);
+	if (v->next != NULL) {
+		i = p->ai.wagon_list[p->ai.num_wagons*2-2];
+		p->ai.wagon_list[p->ai.num_wagons*2-2] = INVALID_VEHICLE;
+		DoCommandByTile(tile, i, 0, DC_EXEC, CMD_SELL_RAIL_WAGON);
+	}
+
+	// Move the wagons onto the train
+	for(i=0; p->ai.wagon_list[i] != INVALID_VEHICLE; i++) {
+		DoCommandByTile(tile, p->ai.wagon_list[i] | (loco_id << 16), 0, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
+	}
+
+	for(i=0; p->ai.order_list_blocks[i] != 0xFF; i++) {
+		AiBuildRec *aib = (&p->ai.src) + p->ai.order_list_blocks[i];
+		bool is_pass = (p->ai.cargo_type == CT_PASSENGERS ||
+							p->ai.cargo_type == CT_MAIL ||
+							(_opt.landscape==LT_NORMAL && p->ai.cargo_type == CT_VALUABLES));
+		Order order;
+
+		order.type = OT_GOTO_STATION;
+		order.flags = 0;
+		order.station = AiGetStationIdByDef(aib->use_tile, aib->cur_building_rule);
+
+		if (!is_pass && i == 1) order.flags |= OF_UNLOAD;
+		if (p->ai.num_want_fullload != 0 && (is_pass || i == 0))
+			order.flags |= OF_FULL_LOAD;
+
+		DoCommandByTile(0, loco_id + (i << 16),	PackOrder(&order), DC_EXEC, CMD_INSERT_ORDER);
+	}
+
+	DoCommandByTile(0, loco_id, 0, DC_EXEC, CMD_START_STOP_TRAIN);
+
+	DoCommandByTile(0, loco_id, _ai_service_interval, DC_EXEC, CMD_CHANGE_TRAIN_SERVICE_INT);
+
+	if (p->ai.num_want_fullload != 0)
+		p->ai.num_want_fullload--;
+
+	if (--p->ai.num_loco_to_build != 0) {
+//		p->ai.loco_id = INVALID_VEHICLE;
+		p->ai.wagon_list[0] = INVALID_VEHICLE;
+	} else {
+		p->ai.state =	AIS_0;
+	}
+}
+
+static void AiStateDeleteRailBlocks(Player *p)
+{
+	int num;
+	AiBuildRec *aib;
+	const AiDefaultBlockData *b;
+
+	num = p->ai.num_build_rec;
+	aib = &p->ai.src;
+	do {
+		if (aib->cur_building_rule != 255) {
+			b = _default_rail_track_data[aib->cur_building_rule]->data;
+			while (b->mode != 4) {
+				DoCommandByTile(TILE_ADD(aib->use_tile, ToTileIndexDiff(b->tileoffs)), 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+				b++;
+			}
+		}
+	} while (++aib,--num);
+
+	p->ai.state = AIS_0;
+}
+
+static bool AiCheckRoadResources(TileIndex tile, const AiDefaultBlockData *p, byte cargo)
+{
+	uint values[NUM_CARGO];
+	int rad;
+
+	if (_patches.modified_catchment) {
+		rad = CA_TRUCK;		//Same as CA_BUS at the moment?
+	} else {			//change that at some point?
+		rad = 4;
+	}
+
+	for(;;p++) {
+		if (p->mode == 4) {
+			return true;
+		} else if (p->mode == 1) {
+			TileIndex tile2 = TILE_ADD(tile, ToTileIndexDiff(p->tileoffs));
+
+			if (cargo & 0x80) {
+				GetProductionAroundTiles(values, tile2, 1, 1, rad);
+				return values[cargo & 0x7F] != 0;
+			} else {
+				GetAcceptanceAroundTiles(values, tile2, 1, 1, rad);
+				return (values[cargo]&~7) != 0;
+			}
+		}
+	}
+}
+
+static bool _want_road_truck_station;
+static int32 AiDoBuildDefaultRoadBlock(TileIndex tile, const AiDefaultBlockData *p, byte flag);
+
+// Returns rule and cost
+static int AiFindBestDefaultRoadBlock(TileIndex tile, byte direction, byte cargo, int32 *cost)
+{
+	int i;
+	const AiDefaultRoadBlock *p;
+
+	_want_road_truck_station = (cargo & 0x7F) != CT_PASSENGERS;
+
+	for(i=0; (p = _road_default_block_data[i]) != NULL; i++) {
+		if (p->dir == direction) {
+			*cost = AiDoBuildDefaultRoadBlock(tile, p->data, 0);
+			if (*cost != CMD_ERROR && AiCheckRoadResources(tile, p->data, cargo))
+				return i;
+		}
+	}
+
+	return -1;
+}
+
+static int32 AiDoBuildDefaultRoadBlock(TileIndex tile, const AiDefaultBlockData *p, byte flag)
+{
+	int32 ret;
+	int32 total_cost = 0;
+	Town *t = NULL;
+	int rating = 0;
+	int roadflag = 0;
+
+	for(;p->mode != 4;p++) {
+		uint c = TILE_MASK(tile + ToTileIndexDiff(p->tileoffs));
+
+		_cleared_town = NULL;
+
+		if (p->mode == 2) {
+			if (IsTileType(c, MP_STREET) &&
+					(_m[c].m5&0xF0)==0 &&
+					(_m[c].m5&p->attr)!=0) {
+				roadflag |= 2;
+
+				// all bits are already built?
+				if ((_m[c].m5&p->attr)==p->attr)
+					continue;
+			}
+
+			ret = DoCommandByTile(c, p->attr, 0, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD);
+			if (CmdFailed(ret)) return CMD_ERROR;
+			total_cost += ret;
+
+			continue;
+		}
+
+		if (p->mode == 0) {
+			// Depot
+			ret = DoCommandByTile(c, p->attr, 0, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_ROAD_DEPOT);
+			goto clear_town_stuff;
+		} else if (p->mode == 1) {
+			if (_want_road_truck_station) {
+				// Truck station
+				ret = DoCommandByTile(c, p->attr, RS_TRUCK, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_ROAD_STOP);
+			} else {
+				// Bus station
+				ret = DoCommandByTile(c, p->attr, RS_BUS, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_ROAD_STOP);
+			}
+clear_town_stuff:;
+
+			if (CmdFailed(ret)) return CMD_ERROR;
+			total_cost += ret;
+
+			if (_cleared_town != NULL) {
+				if (t != NULL && t != _cleared_town)
+					return CMD_ERROR;
+				t = _cleared_town;
+				rating += _cleared_town_rating;
+			}
+		} else if (p->mode == 3) {
+			if (flag & DC_EXEC)
+				continue;
+
+			if (GetTileSlope(c, NULL) != 0)
+				return CMD_ERROR;
+
+			if (!(IsTileType(c, MP_STREET) && (_m[c].m5 & 0xF0) == 0)) {
+				ret = DoCommandByTile(c, 0, 0, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_LANDSCAPE_CLEAR);
+				if (CmdFailed(ret)) return CMD_ERROR;
+			}
+
+		}
+	}
+
+	if (!_want_road_truck_station && !(roadflag&2))
+		return CMD_ERROR;
+
+	if (!(flag & DC_EXEC)) {
+		if (t != NULL && rating > t->ratings[_current_player]) {
+			return CMD_ERROR;
+		}
+	}
+	return total_cost;
+}
+
+// Make sure the blocks are not too close to each other
+static bool AiCheckBlockDistances(Player *p, TileIndex tile)
+{
+	AiBuildRec *aib;
+	int num;
+
+	num = p->ai.num_build_rec;
+	aib = &p->ai.src;
+
+	do {
+		if (aib->cur_building_rule != 255) {
+			if (DistanceManhattan(aib->use_tile, tile) < 9)
+				return false;
+		}
+	} while (++aib, --num);
+
+	return true;
+}
+
+
+static void AiStateBuildDefaultRoadBlocks(Player *p)
+{
+	int i, j;
+	AiBuildRec *aib;
+	int rule;
+	int32 cost;
+
+	// time out?
+	if (++p->ai.timeout_counter == 1388) {
+		p->ai.state = AIS_DELETE_RAIL_BLOCKS;
+		return;
+	}
+
+	// do the following 8 times
+	i = 8;
+	do {
+		// check if we can build the default track
+		aib = &p->ai.src;
+		j = p->ai.num_build_rec;
+		do {
+			// this item has already been built?
+			if (aib->cur_building_rule != 255)
+				continue;
+
+			// adjust the coordinate randomly,
+			// to make sure that we find a position.
+			aib->use_tile = AdjustTileCoordRandomly(aib->spec_tile, aib->rand_rng);
+
+			// check if the road can be built there.
+			rule = AiFindBestDefaultRoadBlock(aib->use_tile,
+				aib->direction, aib->cargo, &cost);
+
+			if (rule == -1) {
+				// cannot build, terraform after a while
+				if (p->ai.state_counter >= 600) {
+					AiDoTerraformLand(aib->use_tile, Random()&3, 3, (int8)p->ai.state_mode);
+				}
+				// also try the other terraform direction
+				if (++p->ai.state_counter >= 1000) {
+					p->ai.state_counter = 0;
+					p->ai.state_mode = -p->ai.state_mode;
+				}
+			} else if (CheckPlayerHasMoney(cost) && AiCheckBlockDistances(p,aib->use_tile)) {
+				int32 r;
+
+				// player has money, build it.
+				aib->cur_building_rule = rule;
+
+				r = AiDoBuildDefaultRoadBlock(
+					aib->use_tile,
+					_road_default_block_data[rule]->data,
+					DC_EXEC | DC_NO_TOWN_RATING
+				);
+				assert(r != CMD_ERROR);
+			}
+		} while (++aib,--j);
+	} while (--i);
+
+	// check if we're done with all of them
+	aib = &p->ai.src;
+	j = p->ai.num_build_rec;
+	do {
+		if (aib->cur_building_rule == 255)
+			return;
+	} while (++aib,--j);
+
+	// yep, all are done. switch state to the rail building state.
+	p->ai.state = AIS_BUILD_ROAD;
+	p->ai.state_mode = 255;
+}
+
+typedef struct {
+	TileIndex final_tile;
+	byte final_dir;
+	byte depth;
+	byte recursive_mode;
+	byte cur_best_dir;
+	byte best_dir;
+	byte cur_best_depth;
+	byte best_depth;
+	uint cur_best_dist;
+	const byte *best_ptr;
+	uint best_dist;
+	TileIndex cur_best_tile, best_tile;
+	TileIndex bridge_end_tile;
+	Player *player;
+	TileInfo ti;
+} AiRoadFinder;
+
+typedef struct AiRoadEnum {
+	TileIndex dest;
+	TileIndex best_tile;
+	int best_track;
+	uint best_dist;
+} AiRoadEnum;
+
+static const byte _dir_by_track[] = {
+	0,1,0,1,2,1, 0,0,
+	2,3,3,2,3,0,
+};
+
+static void AiBuildRoadRecursive(AiRoadFinder *arf, TileIndex tile, int dir);
+
+static bool AiCheckRoadPathBetter(AiRoadFinder *arf, const byte *p)
+{
+	bool better = false;
+
+	if (arf->recursive_mode < 1) {
+		// Mode is 0. This means destination has not been found yet.
+		// If the found path is shorter than the current one, remember it.
+		if (arf->cur_best_dist < arf->best_dist ||
+			(arf->cur_best_dist == arf->best_dist && arf->cur_best_depth < arf->best_depth)) {
+			arf->best_depth = arf->cur_best_depth;
+			arf->best_dist = arf->cur_best_dist;
+			arf->best_dir = arf->cur_best_dir;
+			arf->best_ptr = p;
+			arf->best_tile = arf->cur_best_tile;
+			better = true;
+		}
+	} else if (arf->recursive_mode > 1) {
+		// Mode is 2.
+		if (arf->best_dist != 0 || arf->cur_best_depth < arf->best_depth) {
+			arf->best_depth = arf->cur_best_depth;
+			arf->best_dist = 0;
+			arf->best_ptr = p;
+			arf->best_tile = 0;
+			better = true;
+		}
+	}
+	arf->recursive_mode = 0;
+	arf->cur_best_dist = (uint)-1;
+	arf->cur_best_depth = 0xff;
+
+	return better;
+}
+
+
+static bool AiEnumFollowRoad(TileIndex tile, AiRoadEnum *a, int track, uint length, byte *state)
+{
+	uint dist = DistanceManhattan(tile, a->dest);
+
+	if (dist <= a->best_dist) {
+		TileIndex tile2 = TILE_MASK(tile + TileOffsByDir(_dir_by_track[track]));
+
+		if (IsTileType(tile2, MP_STREET) &&
+				(_m[tile2].m5&0xF0) == 0) {
+			a->best_dist = dist;
+			a->best_tile = tile;
+			a->best_track = track;
+		}
+	}
+
+	return false;
+}
+
+static const uint16 _ai_road_table_and[4] = {
+	0x1009,
+	0x16,
+	0x520,
+	0x2A00,
+};
+
+static bool AiCheckRoadFinished(Player *p)
+{
+	AiRoadEnum are;
+	TileIndex tile;
+	int dir = p->ai.cur_dir_a;
+	uint32 bits;
+	int i;
+
+	are.dest = p->ai.cur_tile_b;
+	tile = TILE_MASK(p->ai.cur_tile_a + TileOffsByDir(dir));
+
+	bits = GetTileTrackStatus(tile, TRANSPORT_ROAD) & _ai_road_table_and[dir];
+	if (bits == 0) {
+		return false;
+	}
+
+	are.best_dist = (uint)-1;
+
+	for_each_bit(i, bits) {
+		FollowTrack(tile, 0x3000 | TRANSPORT_ROAD, _dir_by_track[i], (TPFEnumProc*)AiEnumFollowRoad, NULL, &are);
+	}
+
+	if (DistanceManhattan(tile, are.dest) <= are.best_dist)
+		return false;
+
+	if (are.best_dist == 0)
+		return true;
+
+	p->ai.cur_tile_a = are.best_tile;
+	p->ai.cur_dir_a = _dir_by_track[are.best_track];
+	return false;
+}
+
+
+static bool AiBuildRoadHelper(TileIndex tile, int flags, int type)
+{
+	static const byte _road_bits[] = {
+		8+2,
+		1+4,
+		1+8,
+		4+2,
+		1+2,
+		8+4,
+	};
+	return !CmdFailed(DoCommandByTile(tile, _road_bits[type], 0, flags, CMD_BUILD_ROAD));
+}
+
+static inline void AiCheckBuildRoadBridgeHere(AiRoadFinder *arf, TileIndex tile, const byte *p)
+{
+	TileIndex tile_new;
+	bool flag;
+
+	int dir2 = p[0] & 3;
+
+	FindLandscapeHeightByTile(&arf->ti, tile);
+	if (arf->ti.tileh == _dir_table_1[dir2] || (arf->ti.tileh==0 && arf->ti.z!=0)) {
+		tile_new = tile;
+		// Allow bridges directly over bottom tiles
+		flag = arf->ti.z == 0;
+		for(;;) {
+			if ((TileIndexDiff)tile_new < -TileOffsByDir(dir2)) return; // Wraping around map, no bridge possible!
+			tile_new = TILE_MASK(tile_new + TileOffsByDir(dir2));
+			FindLandscapeHeightByTile(&arf->ti, tile_new);
+			if (arf->ti.tileh != 0 || arf->ti.type == MP_CLEAR || arf->ti.type == MP_TREES) {
+				// Allow a bridge if either we have a tile that's water, rail or street,
+				// or if we found an up tile.
+				if (!flag) return;
+				break;
+			}
+			if (arf->ti.type != MP_WATER && arf->ti.type != MP_RAILWAY && arf->ti.type != MP_STREET)
+				return;
+			flag = true;
+		}
+
+		// Is building a (rail)bridge possible at this place (type doesn't matter)?
+		if (CmdFailed(DoCommandByTile(tile_new, tile, 0x8000, DC_AUTO, CMD_BUILD_BRIDGE)))
+			return;
+		AiBuildRoadRecursive(arf, tile_new, dir2);
+
+		// At the bottom depth, check if the new path is better than the old one.
+		if (arf->depth == 1) {
+			if (AiCheckRoadPathBetter(arf, p))
+				arf->bridge_end_tile = tile_new;
+		}
+	}
+}
+
+static inline void AiCheckBuildRoadTunnelHere(AiRoadFinder *arf, TileIndex tile, const byte *p)
+{
+	FindLandscapeHeightByTile(&arf->ti, tile);
+
+	if (arf->ti.tileh == _dir_table_2[p[0]&3] && arf->ti.z!=0) {
+		int32 cost = DoCommandByTile(tile, 0x200, 0, DC_AUTO, CMD_BUILD_TUNNEL);
+
+		if (!CmdFailed(cost) && cost <= (arf->player->player_money>>4)) {
+			AiBuildRoadRecursive(arf, _build_tunnel_endtile, p[0]&3);
+			if (arf->depth == 1) {
+				AiCheckRoadPathBetter(arf, p);
+			}
+		}
+	}
+}
+
+
+
+static void AiBuildRoadRecursive(AiRoadFinder *arf, TileIndex tile, int dir)
+{
+	const byte *p;
+
+	tile = TILE_MASK(tile + TileOffsByDir(dir));
+
+	// Reached destination?
+	if (tile == arf->final_tile) {
+		if ((arf->final_dir^2) == dir) {
+			arf->recursive_mode = 2;
+			arf->cur_best_depth = arf->depth;
+		}
+		return;
+	}
+
+	// Depth too deep?
+	if (arf->depth >= 4) {
+		uint dist = DistanceMaxPlusManhattan(tile, arf->final_tile);
+		if (dist < arf->cur_best_dist) {
+			// Store the tile that is closest to the final position.
+			arf->cur_best_dist = dist;
+			arf->cur_best_tile = tile;
+			arf->cur_best_dir = dir;
+			arf->cur_best_depth = arf->depth;
+		}
+		return;
+	}
+
+	// Increase recursion depth
+	arf->depth++;
+
+	// Grab pointer to list of stuff that is possible to build
+	p = _ai_table_15[dir];
+
+	// Try to build a single rail in all directions.
+	FindLandscapeHeightByTile(&arf->ti, tile);
+	if (arf->ti.z == 0) {
+		p += 6;
+	} else {
+		do {
+			// Make sure that a road can be built here.
+			if (AiBuildRoadHelper(tile, DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, p[0])) {
+				AiBuildRoadRecursive(arf, tile, p[1]);
+			}
+
+			// At the bottom depth?
+			if (arf->depth == 1) {
+				AiCheckRoadPathBetter(arf, p);
+			}
+
+			p += 2;
+		} while (!(p[0]&0x80));
+	}
+
+	AiCheckBuildRoadBridgeHere(arf, tile, p);
+	AiCheckBuildRoadTunnelHere(arf, tile, p+1);
+
+	arf->depth--;
+}
+
+int sw;
+
+
+static void AiBuildRoadConstruct(Player *p)
+{
+	AiRoadFinder arf;
+	int i;
+	TileIndex tile;
+
+	// Reached destination?
+	if (AiCheckRoadFinished(p)) {
+		p->ai.state_mode = 255;
+		return;
+	}
+
+	// Setup recursive finder and call it.
+	arf.player = p;
+	arf.final_tile = p->ai.cur_tile_b;
+	arf.final_dir = p->ai.cur_dir_b;
+	arf.depth = 0;
+	arf.recursive_mode = 0;
+	arf.best_ptr = NULL;
+	arf.cur_best_dist = (uint)-1;
+	arf.cur_best_depth = 0xff;
+	arf.best_dist = (uint)-1;
+	arf.best_depth =  0xff;
+	arf.cur_best_tile = 0;
+	arf.best_tile = 0;
+	AiBuildRoadRecursive(&arf, p->ai.cur_tile_a, p->ai.cur_dir_a);
+
+	// Reached destination?
+	if (arf.recursive_mode == 2 && arf.cur_best_depth == 0) {
+		p->ai.state_mode = 255;
+		return;
+	}
+
+	// Didn't find anything to build?
+	if (arf.best_ptr == NULL) {
+		// Terraform some
+do_some_terraform:
+		for(i=0; i!=5; i++)
+			AiDoTerraformLand(p->ai.cur_tile_a, p->ai.cur_dir_a, 3, 0);
+
+		if (++p->ai.state_counter == 21) {
+			p->ai.state_mode = 1;
+
+			p->ai.cur_tile_a = TILE_MASK(p->ai.cur_tile_a + TileOffsByDir(p->ai.cur_dir_a));
+			p->ai.cur_dir_a ^= 2;
+			p->ai.state_counter = 0;
+		}
+		return;
+	}
+
+	tile = TILE_MASK(p->ai.cur_tile_a + TileOffsByDir(p->ai.cur_dir_a));
+
+	if (arf.best_ptr[0]&0x80) {
+		int i;
+		int32 bridge_len;
+		p->ai.cur_tile_a = arf.bridge_end_tile;
+		bridge_len = GetBridgeLength(tile, p->ai.cur_tile_a); // tile
+
+		/*	Figure out what (road)bridge type to build
+				start with best bridge, then go down to worse and worse bridges
+				unnecessary to check for worse bridge (i=0), since AI will always build that.
+				AI is so fucked up that fixing this small thing will probably not solve a thing
+		*/
+		for(i = 10; i != 0; i--) {
+			if (CheckBridge_Stuff(i, bridge_len)) {
+				int32 cost = DoCommandByTile(tile, p->ai.cur_tile_a, i + (0x80 << 8), DC_AUTO, CMD_BUILD_BRIDGE);
+				if (!CmdFailed(cost) && cost < (p->player_money >> 5))
+					break;
+			}
+		}
+
+		// Build it
+		DoCommandByTile(tile, p->ai.cur_tile_a, i + (0x80 << 8), DC_AUTO | DC_EXEC, CMD_BUILD_BRIDGE);
+
+		p->ai.state_counter = 0;
+	} else if (arf.best_ptr[0]&0x40) {
+		// tunnel
+		DoCommandByTile(tile, 0x200, 0, DC_AUTO | DC_EXEC, CMD_BUILD_TUNNEL);
+		p->ai.cur_tile_a = _build_tunnel_endtile;
+		p->ai.state_counter = 0;
+	} else {
+
+		// road
+		if (!AiBuildRoadHelper(tile, DC_EXEC | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, arf.best_ptr[0]))
+			goto do_some_terraform;
+
+		p->ai.cur_dir_a = arf.best_ptr[1];
+		p->ai.cur_tile_a = tile;
+		p->ai.state_counter = 0;
+	}
+
+	if (arf.best_tile != 0) {
+		for(i=0; i!=2; i++)
+			AiDoTerraformLand(arf.best_tile, arf.best_dir, 3, 0);
+	}
+}
+
+
+static void AiBuildRoad(Player *p)
+{
+	int i;
+
+	if (p->ai.state_mode < 1) {
+		// Construct mode, build new road.
+		AiBuildRoadConstruct(p);
+	} else if (p->ai.state_mode == 1) {
+		// Destruct mode, not implemented for roads.
+		p->ai.state_mode = 2;
+		p->ai.state_counter = 0;
+	} else if (p->ai.state_mode == 2) {
+
+		// Terraform some and then try building again.
+		for(i=0; i!=4; i++)
+			AiDoTerraformLand(p->ai.cur_tile_a, p->ai.cur_dir_a, 3, 0);
+
+		if (++p->ai.state_counter == 4) {
+			p->ai.state_counter = 0;
+			p->ai.state_mode = 0;
+		}
+	}
+}
+
+static TileIndex AiGetRoadBlockEdge(byte rule, TileIndex tile, int *dir)
+{
+	const AiDefaultBlockData *p = _road_default_block_data[rule]->data;
+	while (p->mode != 1) p++;
+	*dir = p->attr;
+	return TILE_ADD(tile, ToTileIndexDiff(p->tileoffs));
+}
+
+
+static void AiStateBuildRoad(Player *p)
+{
+	int num;
+	AiBuildRec *aib;
+	byte cmd;
+	TileIndex tile;
+	int dir;
+
+	// time out?
+	if (++p->ai.timeout_counter == 1388) {
+		p->ai.state = AIS_DELETE_ROAD_BLOCKS;
+		return;
+	}
+
+	// Currently building a road between two points?
+	if (p->ai.state_mode != 255) {
+		AiBuildRoad(p);
+
+		// Alternate between edges
+		swap_tile(&p->ai.start_tile_a, &p->ai.start_tile_b);
+		swap_tile(&p->ai.cur_tile_a, &p->ai.cur_tile_b);
+		swap_byte(&p->ai.start_dir_a, &p->ai.start_dir_b);
+		swap_byte(&p->ai.cur_dir_a, &p->ai.cur_dir_b);
+
+		sw ^= 1;
+		return;
+	}
+
+	// Now, find two new points to build between
+	num = p->ai.num_build_rec;
+	aib = &p->ai.src;
+
+	for(;;) {
+		cmd = aib->buildcmd_a;
+		aib->buildcmd_a = 255;
+		if (cmd != 255) break;
+
+		aib++;
+		if (--num == 0) {
+			p->ai.state = AIS_BUILD_ROAD_VEHICLES;
+			return;
+		}
+	}
+
+	// Find first edge to build from.
+	tile = AiGetRoadBlockEdge(aib->cur_building_rule, aib->use_tile, &dir);
+	p->ai.start_tile_a = tile;
+	p->ai.cur_tile_a = tile;
+	p->ai.start_dir_a = dir;
+	p->ai.cur_dir_a = dir;
+
+	// Find second edge to build to
+	aib = (&p->ai.src) + (cmd&0xF);
+	tile = AiGetRoadBlockEdge(aib->cur_building_rule, aib->use_tile, &dir);
+	p->ai.start_tile_b = tile;
+	p->ai.cur_tile_b = tile;
+	p->ai.start_dir_b = dir;
+	p->ai.cur_dir_b = dir;
+
+	// And setup state.
+	p->ai.state_mode = 2;
+	p->ai.state_counter = 0;
+	p->ai.banned_tile_count = 0;
+}
+
+static int AiGetStationIdFromRoadBlock(TileIndex tile, int id)
+{
+	const AiDefaultBlockData *p = _road_default_block_data[id]->data;
+	while (p->mode != 1) p++;
+	return _m[TILE_ADD(tile, ToTileIndexDiff(p->tileoffs))].m2;
+}
+
+static void AiStateBuildRoadVehicles(Player *p)
+{
+	const AiDefaultBlockData *ptr;
+	TileIndex tile;
+	uint loco_id;
+	int veh, i;
+
+	ptr = _road_default_block_data[p->ai.src.cur_building_rule]->data;
+	for(;ptr->mode != 0;ptr++) {}
+	tile = TILE_ADD(p->ai.src.use_tile, ToTileIndexDiff(ptr->tileoffs));
+
+	veh = AiChooseRoadVehToBuild(p->ai.cargo_type, p->player_money, tile);
+	if (veh == -1) {
+		p->ai.state = AIS_0;
+		return;
+	}
+
+	if (CmdFailed(DoCommandByTile(tile, veh, 0, DC_EXEC, CMD_BUILD_ROAD_VEH))) return;
+
+	loco_id = _new_roadveh_id;
+
+	for(i=0; p->ai.order_list_blocks[i] != 0xFF; i++) {
+		AiBuildRec *aib = (&p->ai.src) + p->ai.order_list_blocks[i];
+		bool is_pass = (p->ai.cargo_type == CT_PASSENGERS ||
+							p->ai.cargo_type == CT_MAIL ||
+							(_opt.landscape==LT_NORMAL && p->ai.cargo_type == CT_VALUABLES));
+		Order order;
+
+		order.type = OT_GOTO_STATION;
+		order.flags = 0;
+		order.station = AiGetStationIdFromRoadBlock(aib->use_tile, aib->cur_building_rule);
+
+		if (!is_pass && i == 1) order.flags |= OF_UNLOAD;
+		if (p->ai.num_want_fullload != 0 && (is_pass || i == 0))
+			order.flags |= OF_FULL_LOAD;
+
+		DoCommandByTile(0, loco_id + (i << 16),	PackOrder(&order), DC_EXEC, CMD_INSERT_ORDER);
+	}
+
+	DoCommandByTile(0, loco_id, 0, DC_EXEC, CMD_START_STOP_ROADVEH);
+
+	DoCommandByTile(0, loco_id, _ai_service_interval, DC_EXEC, CMD_CHANGE_TRAIN_SERVICE_INT);
+
+	if (p->ai.num_want_fullload != 0)
+		p->ai.num_want_fullload--;
+
+	if (--p->ai.num_loco_to_build == 0) {
+		p->ai.state =	AIS_0;
+	}
+}
+
+static void AiStateDeleteRoadBlocks(Player *p)
+{
+	int num;
+	AiBuildRec *aib;
+	const AiDefaultBlockData *b;
+
+	num = p->ai.num_build_rec;
+	aib = &p->ai.src;
+	do {
+		if (aib->cur_building_rule != 255) {
+			b = _road_default_block_data[aib->cur_building_rule]->data;
+			while (b->mode != 4) {
+				if (b->mode <= 1) {
+					DoCommandByTile(TILE_ADD(aib->use_tile, ToTileIndexDiff(b->tileoffs)), 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+				}
+				b++;
+			}
+		}
+	} while (++aib,--num);
+
+	p->ai.state = AIS_0;
+}
+
+static bool AiCheckIfHangar(Station *st)
+{
+	TileIndex tile = st->airport_tile;
+
+	// HANGAR of airports
+	// 0x20 - hangar large airport (32)
+	// 0x41 - hangar small airport (65)
+	return (_m[tile].m5 == 32 || _m[tile].m5 == 65);
+}
+
+static void AiStateAirportStuff(Player *p)
+{
+	Station *st;
+	byte acc_planes;
+	int i;
+	AiBuildRec *aib;
+	byte rule;
+
+	// Here we look for an airport we could use instead of building a new
+	// one. If we find such an aiport for any waypoint,
+	// AiStateBuildDefaultAirportBlocks() will kindly skip that one when
+	// building the waypoints.
+
+	i = 0;
+	do {
+		// We do this all twice - once for the source (town in the case
+		// of oilrig route) and then for the destination (oilrig in the
+		// case of oilrig route).
+		aib = &p->ai.src + i;
+
+		FOR_ALL_STATIONS(st) {
+			// Dismiss ghost stations.
+			if (st->xy == 0)
+				continue;
+
+			// Is this an airport?
+			if (!(st->facilities & FACIL_AIRPORT))
+				continue;
+
+			// Do we own the airport? (Oilrigs aren't owned, though.)
+			if (st->owner != OWNER_NONE && st->owner != _current_player)
+				continue;
+
+			acc_planes = GetAirport(st->airport_type)->acc_planes;
+
+			// Dismiss heliports, unless we are checking an oilrig.
+			if (acc_planes == HELICOPTERS_ONLY && !(p->ai.build_kind == 1 && i == 1))
+				continue;
+
+			// Dismiss country airports if we are doing the other
+			// endpoint of an oilrig route.
+			if (acc_planes == AIRCRAFT_ONLY && (p->ai.build_kind == 1 && i == 0))
+				continue;
+
+			// Dismiss airports too far away.
+			if (DistanceMax(st->airport_tile, aib->spec_tile) > aib->rand_rng)
+				continue;
+
+			// It's ideal airport, let's take it!
+
+			/* XXX: This part is utterly broken - rule should
+			 * contain number of the rule appropriate for the
+			 * airport type (country, town, ...), see
+			 * _airport_default_block_data (rule is just an index
+			 * in this array). But the only difference between the
+			 * currently existing two rules (rule 0 - town and rule
+			 * 1 - country) is the attr field which is used only
+			 * when building new airports - and that's irrelevant
+			 * for us. So using just about any rule will suffice
+			 * here for now (some of the new airport types would be
+			 * broken because they will probably need different
+			 * tileoff values etc), no matter that
+			 * AiCheckIfHangar() makes no sense. --pasky */
+			if (acc_planes == HELICOPTERS_ONLY) {
+				/* Heliports should have maybe own rulesets but
+				 * OTOH we don't want AI to pick them up when
+				 * looking for a suitable airport type to build.
+				 * So any of rules 0 or 1 would do for now. The
+				 * original rule number was 2 but that's a bug
+				 * because we have no such rule. */
+				rule = 1;
+			} else {
+				rule = AiCheckIfHangar(st);
+			}
+
+			aib->cur_building_rule = rule;
+			aib->use_tile = st->airport_tile;
+			break;
+		}
+	} while (++i != p->ai.num_build_rec);
+
+	p->ai.state = AIS_BUILD_DEFAULT_AIRPORT_BLOCKS;
+	p->ai.state_mode = 255;
+	p->ai.state_counter = 0;
+}
+
+static int32 AiDoBuildDefaultAirportBlock(TileIndex tile, const AiDefaultBlockData *p, byte flag)
+{
+	int32 total_cost = 0, ret;
+
+	for(;p->mode == 0;p++) {
+		if (!HASBIT(_avail_aircraft, p->attr))
+			return CMD_ERROR;
+		ret = DoCommandByTile(TILE_MASK(tile + ToTileIndexDiff(p->tileoffs)), p->attr,0,flag | DC_AUTO | DC_NO_WATER,CMD_BUILD_AIRPORT);
+		if (CmdFailed(ret)) return CMD_ERROR;
+		total_cost += ret;
+	}
+
+	return total_cost;
+}
+
+static bool AiCheckAirportResources(TileIndex tile, const AiDefaultBlockData *p, byte cargo)
+{
+	uint values[NUM_CARGO];
+	int w,h;
+	int rad;
+
+	if (_patches.modified_catchment) {
+		rad = CA_AIR_LARGE;		//I Have NFI what airport the
+	} else {				//AI is going to build here
+		rad = 4;
+	}
+
+	for(;p->mode==0;p++) {
+		TileIndex tile2 = TILE_ADD(tile, ToTileIndexDiff(p->tileoffs));
+
+		w = _airport_size_x[p->attr];
+		h = _airport_size_y[p->attr];
+		if (cargo & 0x80) {
+			GetProductionAroundTiles(values, tile2, w, h, rad);
+			return values[cargo & 0x7F] != 0;
+		} else {
+			GetAcceptanceAroundTiles(values, tile2, w, h, rad);
+			return values[cargo] >= 8;
+		}
+	}
+	return true;
+}
+
+static int AiFindBestDefaultAirportBlock(TileIndex tile, byte cargo, byte heli, int32 *cost)
+{
+	int i;
+	const AiDefaultBlockData *p;
+	for(i=0; (p = _airport_default_block_data[i]) != NULL; i++) {
+		// If we are doing a helicopter service, avoid building
+		// airports where they can't land.
+		if (heli && GetAirport(p->attr)->acc_planes == AIRCRAFT_ONLY)
+			continue;
+
+		*cost = AiDoBuildDefaultAirportBlock(tile, p, 0);
+		if (*cost != CMD_ERROR && AiCheckAirportResources(tile, p, cargo))
+			return i;
+	}
+	return -1;
+}
+
+static void AiStateBuildDefaultAirportBlocks(Player *p)
+{
+	int i, j;
+	AiBuildRec *aib;
+	int rule;
+	int32 cost;
+
+	// time out?
+	if (++p->ai.timeout_counter == 1388) {
+		p->ai.state = AIS_0;
+		return;
+	}
+
+	// do the following 8 times
+	i = 8;
+	do {
+		// check if we can build the default
+		aib = &p->ai.src;
+		j = p->ai.num_build_rec;
+		do {
+			// this item has already been built?
+			if (aib->cur_building_rule != 255)
+				continue;
+
+			// adjust the coordinate randomly,
+			// to make sure that we find a position.
+			aib->use_tile = AdjustTileCoordRandomly(aib->spec_tile, aib->rand_rng);
+
+			// check if the aircraft stuff can be built there.
+			rule = AiFindBestDefaultAirportBlock(aib->use_tile, aib->cargo, p->ai.build_kind, &cost);
+
+#if 0
+			if (!IsTileType(aib->use_tile, MP_STREET) &&
+					!IsTileType(aib->use_tile, MP_RAILWAY) &&
+					!IsTileType(aib->use_tile, MP_STATION)
+					) {
+
+				_m[aib->use_tile].type_height = 0xa1;
+				_m[aib->use_tile].m5 = 0x80;
+				MarkTileDirtyByTile(aib->use_tile);
+			}
+#endif
+//			SetRedErrorSquare(aib->use_tile);
+
+			if (rule == -1) {
+				// cannot build, terraform after a while
+				if (p->ai.state_counter >= 600) {
+					AiDoTerraformLand(aib->use_tile, Random()&3, 3, (int8)p->ai.state_mode);
+				}
+				// also try the other terraform direction
+				if (++p->ai.state_counter >= 1000) {
+					p->ai.state_counter = 0;
+					p->ai.state_mode = -p->ai.state_mode;
+				}
+			} else if (CheckPlayerHasMoney(cost) && AiCheckBlockDistances(p,aib->use_tile)) {
+				// player has money, build it.
+				int32 r;
+
+				aib->cur_building_rule = rule;
+
+				r = AiDoBuildDefaultAirportBlock(
+					aib->use_tile,
+					_airport_default_block_data[rule],
+					DC_EXEC | DC_NO_TOWN_RATING
+				);
+				assert(r != CMD_ERROR);
+			}
+		} while (++aib,--j);
+	} while (--i);
+
+	// check if we're done with all of them
+	aib = &p->ai.src;
+	j = p->ai.num_build_rec;
+	do {
+		if (aib->cur_building_rule == 255)
+			return;
+	} while (++aib,--j);
+
+	// yep, all are done. switch state.
+	p->ai.state = AIS_BUILD_AIRCRAFT_VEHICLES;
+}
+
+static int AiGetStationIdFromAircraftBlock(TileIndex tile, int id)
+{
+	const AiDefaultBlockData *p = _airport_default_block_data[id];
+	while (p->mode != 1) p++;
+	return _m[TILE_ADD(tile, ToTileIndexDiff(p->tileoffs))].m2;
+}
+
+static void AiStateBuildAircraftVehicles(Player *p)
+{
+	const AiDefaultBlockData *ptr;
+	TileIndex tile;
+	int veh;
+	int i;
+	uint loco_id;
+
+	ptr = _airport_default_block_data[p->ai.src.cur_building_rule];
+	for(;ptr->mode!=0;ptr++) {}
+
+	tile = TILE_ADD(p->ai.src.use_tile, ToTileIndexDiff(ptr->tileoffs));
+
+	veh = AiChooseAircraftToBuild(p->player_money, p->ai.build_kind!=0 ? 1 : 0);
+	if (veh == -1) {
+		return;
+	}
+
+	if (CmdFailed(DoCommandByTile(tile, veh, 0, DC_EXEC, CMD_BUILD_AIRCRAFT))) return;
+	loco_id = _new_aircraft_id;
+
+	for(i=0; p->ai.order_list_blocks[i] != 0xFF; i++) {
+		AiBuildRec *aib = (&p->ai.src) + p->ai.order_list_blocks[i];
+		bool is_pass = (p->ai.cargo_type == CT_PASSENGERS || p->ai.cargo_type == CT_MAIL);
+		Order order;
+
+		order.type = OT_GOTO_STATION;
+		order.flags = 0;
+		order.station = AiGetStationIdFromAircraftBlock(aib->use_tile, aib->cur_building_rule);
+
+		if (!is_pass && i == 1) order.flags |= OF_UNLOAD;
+		if (p->ai.num_want_fullload != 0 && (is_pass || i == 0))
+			order.flags |= OF_FULL_LOAD;
+
+		DoCommandByTile(0, loco_id + (i << 16), PackOrder(&order), DC_EXEC, CMD_INSERT_ORDER);
+	}
+
+	DoCommandByTile(0, loco_id, 0, DC_EXEC, CMD_START_STOP_AIRCRAFT);
+
+	DoCommandByTile(0, loco_id, _ai_service_interval, DC_EXEC, CMD_CHANGE_TRAIN_SERVICE_INT);
+
+	if (p->ai.num_want_fullload != 0)
+		p->ai.num_want_fullload--;
+
+	if (--p->ai.num_loco_to_build == 0) {
+		p->ai.state =	AIS_0;
+	}
+}
+
+static void AiStateCheckShipStuff(Player *p)
+{
+	// XXX
+	error("!AiStateCheckShipStuff");
+}
+
+static void AiStateBuildDefaultShipBlocks(Player *p)
+{
+	// XXX
+	error("!AiStateBuildDefaultShipBlocks");
+}
+
+static void AiStateDoShipStuff(Player *p)
+{
+	// XXX
+	error("!AiStateDoShipStuff");
+}
+
+static void AiStateSellVeh(Player *p)
+{
+	Vehicle *v = p->ai.cur_veh;
+
+	if (v->owner == _current_player) {
+		if (v->type == VEH_Train) {
+
+			if (!IsTileDepotType(v->tile, TRANSPORT_RAIL) || v->u.rail.track != 0x80 || !(v->vehstatus&VS_STOPPED)) {
+				if (v->current_order.type != OT_GOTO_DEPOT)
+					DoCommandByTile(0, v->index, 0, DC_EXEC, CMD_TRAIN_GOTO_DEPOT);
+				goto going_to_depot;
+			}
+
+			// Sell whole train
+			DoCommandByTile(v->tile, v->index, 1, DC_EXEC, CMD_SELL_RAIL_WAGON);
+
+		} else if (v->type == VEH_Road) {
+			if (!IsTileDepotType(v->tile, TRANSPORT_ROAD) || v->u.road.state != 254 || !(v->vehstatus&VS_STOPPED)) {
+				if (v->current_order.type != OT_GOTO_DEPOT)
+					DoCommandByTile(0, v->index, 0, DC_EXEC, CMD_SEND_ROADVEH_TO_DEPOT);
+				goto going_to_depot;
+			}
+
+			DoCommandByTile(0, v->index, 0, DC_EXEC, CMD_SELL_ROAD_VEH);
+		} else if (v->type == VEH_Aircraft) {
+			if (!IsAircraftHangarTile(v->tile) && !(v->vehstatus&VS_STOPPED)) {
+				if (v->current_order.type != OT_GOTO_DEPOT)
+					DoCommandByTile(0, v->index, 0, DC_EXEC, CMD_SEND_AIRCRAFT_TO_HANGAR);
+				goto going_to_depot;
+			}
+
+			DoCommandByTile(0, v->index, 0, DC_EXEC, CMD_SELL_AIRCRAFT);
+			} else if (v->type == VEH_Ship) {
+			// XXX: not implemented
+			error("!v->type == VEH_Ship");
+		}
+	}
+
+	goto return_to_loop;
+going_to_depot:;
+	if (++p->ai.state_counter <= 832)
+		return;
+
+	if (v->current_order.type == OT_GOTO_DEPOT) {
+		v->current_order.type = OT_DUMMY;
+		v->current_order.flags = 0;
+		InvalidateWindow(WC_VEHICLE_VIEW, v->index);
+	}
+return_to_loop:;
+	p->ai.state = AIS_VEH_LOOP;
+}
+
+static void AiStateRemoveStation(Player *p)
+{
+	// Remove stations that aren't in use by any vehicle
+	byte *in_use;
+	const byte *used;
+	const Order *ord;
+	const Station *st;
+	TileIndex tile;
+
+	// Go to this state when we're done.
+	p->ai.state = AIS_1;
+
+	// Get a list of all stations that are in use by a vehicle
+	in_use = malloc(GetStationPoolSize());
+	memset(in_use, 0, GetStationPoolSize());
+	FOR_ALL_ORDERS(ord) {
+		if (ord->type == OT_GOTO_STATION)
+			in_use[ord->station] = 1;
+	}
+
+	// Go through all stations and delete those that aren't in use
+	used = in_use;
+	FOR_ALL_STATIONS(st) {
+		if (st->xy != 0 && st->owner == _current_player && !*used &&
+				( (st->bus_stops != NULL && (tile = st->bus_stops->xy) != 0) ||
+					(st->truck_stops != NULL && (tile = st->truck_stops->xy)) != 0 ||
+					(tile = st->train_tile) != 0 ||
+					(tile = st->dock_tile) != 0 ||
+					(tile = st->airport_tile) != 0)) {
+			DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+		}
+		used++;
+	}
+
+	free(in_use);
+}
+
+static void AiRemovePlayerRailOrRoad(Player *p, TileIndex tile)
+{
+	byte m5;
+
+	if (IsTileType(tile, MP_RAILWAY)) {
+		if (!IsTileOwner(tile, _current_player)) return;
+
+		m5 = _m[tile].m5;
+		if ((m5&~0x3) != 0xC0) {
+is_rail_crossing:;
+			m5 = GetRailTrackStatus(tile);
+
+			if (m5 == 0xC || m5 == 0x30)
+				return;
+
+			if (m5&0x25) {
+pos_0:
+				if (!(GetRailTrackStatus(TILE_MASK(tile - TileDiffXY(1, 0))) & 0x19)) {
+					p->ai.cur_dir_a = 0;
+					p->ai.cur_tile_a = tile;
+					p->ai.state = AIS_REMOVE_SINGLE_RAIL_TILE;
+					return;
+				}
+			}
+
+			if (m5&0x2A) {
+pos_1:
+				if (!(GetRailTrackStatus(TILE_MASK(tile + TileDiffXY(0, 1))) & 0x16)) {
+					p->ai.cur_dir_a = 1;
+					p->ai.cur_tile_a = tile;
+					p->ai.state = AIS_REMOVE_SINGLE_RAIL_TILE;
+					return;
+				}
+			}
+
+			if (m5&0x19) {
+pos_2:
+				if (!(GetRailTrackStatus(TILE_MASK(tile + TileDiffXY(1, 0))) & 0x25)) {
+					p->ai.cur_dir_a = 2;
+					p->ai.cur_tile_a = tile;
+					p->ai.state = AIS_REMOVE_SINGLE_RAIL_TILE;
+					return;
+				}
+			}
+
+			if (m5&0x16) {
+pos_3:
+				if (!(GetRailTrackStatus(TILE_MASK(tile - TileDiffXY(0, 1))) & 0x2A)) {
+					p->ai.cur_dir_a = 3;
+					p->ai.cur_tile_a = tile;
+					p->ai.state = AIS_REMOVE_SINGLE_RAIL_TILE;
+					return;
+				}
+			}
+		} else {
+			static const byte _depot_bits[] = {0x19,0x16,0x25,0x2A};
+
+			m5 &= 3;
+			if (GetRailTrackStatus(tile + TileOffsByDir(m5)) & _depot_bits[m5])
+				return;
+
+			DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+		}
+	} else if (IsTileType(tile, MP_STREET)) {
+		if (!IsTileOwner(tile, _current_player)) return;
+
+		if (IsLevelCrossing(tile))
+			goto is_rail_crossing;
+
+		if ( (_m[tile].m5&0xF0) == 0x20) {
+			int dir;
+
+			// Check if there are any stations around.
+			if (IsTileType(tile + TileDiffXY(-1, 0), MP_STATION) &&
+					IsTileOwner(tile + TileDiffXY(-1, 0), _current_player))
+						return;
+
+			if (IsTileType(tile + TileDiffXY(1, 0), MP_STATION) &&
+					IsTileOwner(tile + TileDiffXY(1, 0), _current_player))
+						return;
+
+			if (IsTileType(tile + TileDiffXY(0, -1), MP_STATION) &&
+					IsTileOwner(tile + TileDiffXY(0, -1), _current_player))
+						return;
+
+			if (IsTileType(tile + TileDiffXY(0, 1), MP_STATION) &&
+					IsTileOwner(tile + TileDiffXY(0, 1), _current_player))
+						return;
+
+			dir = _m[tile].m5 & 3;
+
+			DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+			DoCommandByTile(
+				TILE_MASK(tile + TileOffsByDir(dir)),
+				8 >> (dir ^ 2),
+				0,
+				DC_EXEC,
+				CMD_REMOVE_ROAD);
+		}
+	} else if (IsTileType(tile, MP_TUNNELBRIDGE)) {
+		byte b;
+
+		if (!IsTileOwner(tile, _current_player) || (_m[tile].m5 & 0xC6) != 0x80)
+			return;
+
+		m5 = 0;
+
+		b = _m[tile].m5 & 0x21;
+		if (b == 0) goto pos_0;
+		if (b == 1) goto pos_3;
+		if (b == 0x20) goto pos_2;
+		goto pos_1;
+	}
+}
+
+static void AiStateRemoveTrack(Player *p)
+{
+	/* Was 1000 for standard 8x8 maps. */
+	int num = MapSizeX() * 4;
+
+	do {
+		TileIndex tile = ++p->ai.state_counter;
+
+		// Iterated all tiles?
+		if (tile >= MapSize()) {
+			p->ai.state = AIS_REMOVE_STATION;
+			return;
+		}
+
+		// Remove player stuff in that tile
+		AiRemovePlayerRailOrRoad(p, tile);
+		if (p->ai.state != AIS_REMOVE_TRACK)
+			return;
+	} while (--num);
+}
+
+static void AiStateRemoveSingleRailTile(Player *p)
+{
+	// Remove until we can't remove more.
+	if (!AiRemoveTileAndGoForward(p)) {
+		p->ai.state = AIS_REMOVE_TRACK;
+	}
+}
+
+static AiStateAction * const _ai_actions[] = {
+	AiCase0,
+	AiCase1,
+	AiStateVehLoop,
+	AiStateCheckReplaceVehicle,
+	AiStateDoReplaceVehicle,
+	AiStateWantNewRoute,
+
+	AiStateBuildDefaultRailBlocks,
+	AiStateBuildRail,
+	AiStateBuildRailVeh,
+	AiStateDeleteRailBlocks,
+
+	AiStateBuildDefaultRoadBlocks,
+	AiStateBuildRoad,
+	AiStateBuildRoadVehicles,
+	AiStateDeleteRoadBlocks,
+
+	AiStateAirportStuff,
+	AiStateBuildDefaultAirportBlocks,
+	AiStateBuildAircraftVehicles,
+
+	AiStateCheckShipStuff,
+	AiStateBuildDefaultShipBlocks,
+	AiStateDoShipStuff,
+
+	AiStateSellVeh,
+	AiStateRemoveStation,
+	AiStateRemoveTrack,
+
+	AiStateRemoveSingleRailTile
+};
+
+extern void ShowBuyCompanyDialog(uint player);
+
+static void AiHandleTakeover(Player *p)
+{
+	if (p->bankrupt_timeout != 0) {
+		if ((p->bankrupt_timeout-=8) > 0)
+			return;
+		p->bankrupt_timeout = 0;
+		DeleteWindowById(WC_BUY_COMPANY, _current_player);
+		if (_current_player == _local_player) {
+			AskExitToGameMenu();
+			return;
+		}
+		if (IS_HUMAN_PLAYER(_current_player))
+			return;
+	}
+
+	if (p->bankrupt_asked == 255)
+		return;
+
+	{
+		uint asked = p->bankrupt_asked;
+		Player *pp, *best_pl = NULL;
+		int32 best_val = -1;
+		uint old_p;
+
+		// Ask the guy with the highest performance hist.
+		FOR_ALL_PLAYERS(pp) {
+			if (pp->is_active &&
+					!(asked&1) &&
+					pp->bankrupt_asked == 0 &&
+					best_val < pp->old_economy[1].performance_history) {
+				best_val = pp->old_economy[1].performance_history;
+				best_pl = pp;
+			}
+			asked>>=1;
+		}
+
+		// Asked all players?
+		if (best_val == -1) {
+			p->bankrupt_asked = 255;
+			return;
+		}
+
+		SETBIT(p->bankrupt_asked, best_pl->index);
+
+		if (best_pl->index == _local_player) {
+			p->bankrupt_timeout = 4440;
+			ShowBuyCompanyDialog(_current_player);
+			return;
+		}
+		if (IS_HUMAN_PLAYER(best_pl->index))
+			return;
+
+		// Too little money for computer to buy it?
+		if (best_pl->player_money >> 1 >= p->bankrupt_value) {
+			// Computer wants to buy it.
+			old_p = _current_player;
+			_current_player = p->index;
+			DoCommandByTile(0, old_p, 0, DC_EXEC, CMD_BUY_COMPANY);
+			_current_player = old_p;
+		}
+	}
+}
+
+static void AiAdjustLoan(Player *p)
+{
+	int32 base = AiGetBasePrice(p);
+
+	if (p->player_money > base * 1400) {
+		// Decrease loan
+		if (p->current_loan != 0) {
+			DoCommandByTile(0, 0, 0, DC_EXEC, CMD_DECREASE_LOAN);
+		}
+	} else if (p->player_money < base * 500) {
+		// Increase loan
+		if (p->current_loan < _economy.max_loan &&
+				p->num_valid_stat_ent >= 2 &&
+				-(p->old_economy[0].expenses+p->old_economy[1].expenses) < base * 60) {
+			DoCommandByTile(0, 0, 0, DC_EXEC, CMD_INCREASE_LOAN);
+		}
+	}
+}
+
+static void AiBuildCompanyHQ(Player *p)
+{
+	TileIndex tile;
+
+	if (p->location_of_house == 0 &&
+			p->last_build_coordinate != 0) {
+		tile = AdjustTileCoordRandomly(p->last_build_coordinate, 8);
+		DoCommandByTile(tile, 0, 0, DC_EXEC | DC_AUTO | DC_NO_WATER, CMD_BUILD_COMPANY_HQ);
+	}
+}
+
+
+void AiDoGameLoop(Player *p)
+{
+	_cur_ai_player = p;
+
+	if (p->bankrupt_asked != 0) {
+		AiHandleTakeover(p);
+		return;
+	}
+
+	// Ugly hack to make sure the service interval of the AI is good, not looking
+	//  to the patch-setting
+	// Also, it takes into account the setting if the service-interval is in days
+	//  or in %
+	_ai_service_interval = _patches.servint_ispercent?80:180;
+
+	if (IS_HUMAN_PLAYER(_current_player))
+		return;
+
+	AiAdjustLoan(p);
+	AiBuildCompanyHQ(p);
+
+	if (_opt.diff.competitor_speed == 4) {
+		/* ultraspeed */
+		_ai_actions[p->ai.state](p);
+		if (p->bankrupt_asked != 0)
+			return;
+	} else if (_opt.diff.competitor_speed != 3) {
+		p->ai.tick++;
+		if (!(p->ai.tick&1))
+			return;
+		if (_opt.diff.competitor_speed != 2) {
+			if (!(p->ai.tick&2))
+				return;
+			if (_opt.diff.competitor_speed == 0) {
+				if (!(p->ai.tick&4))
+					return;
+			}
+		}
+	}
+#if 0
+	{
+		static byte old_state = 99;
+		static bool hasdots = false;
+		char *_ai_state_names[]={
+			"AiCase0",
+			"AiCase1",
+			"AiStateVehLoop",
+			"AiStateCheckReplaceVehicle",
+			"AiStateDoReplaceVehicle",
+			"AiStateWantNewRoute",
+			"AiStateBuildDefaultRailBlocks",
+			"AiStateBuildRail",
+			"AiStateBuildRailVeh",
+			"AiStateDeleteRailBlocks",
+			"AiStateBuildDefaultRoadBlocks",
+			"AiStateBuildRoad",
+			"AiStateBuildRoadVehicles",
+			"AiStateDeleteRoadBlocks",
+			"AiStateAirportStuff",
+			"AiStateBuildDefaultAirportBlocks",
+			"AiStateBuildAircraftVehicles",
+			"AiStateCheckShipStuff",
+			"AiStateBuildDefaultShipBlocks",
+			"AiStateDoShipStuff",
+			"AiStateSellVeh",
+			"AiStateRemoveStation",
+			"AiStateRemoveTrack",
+			"AiStateRemoveSingleRailTile"
+		};
+
+		if (p->ai.state != old_state) {
+			if (hasdots)
+				printf("\n");
+			hasdots=false;
+			printf("AiState: %s\n", _ai_state_names[old_state=p->ai.state]);
+		} else {
+			printf(".");
+			hasdots=true;
+		}
+	}
+#endif
+
+	_ai_actions[p->ai.state](p);
+}