tunnelbridge_cmd.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00016 #include "stdafx.h"
00017 #include "newgrf_object.h"
00018 #include "viewport_func.h"
00019 #include "cmd_helper.h"
00020 #include "command_func.h"
00021 #include "town.h"
00022 #include "train.h"
00023 #include "ship.h"
00024 #include "roadveh.h"
00025 #include "pathfinder/yapf/yapf_cache.h"
00026 #include "newgrf_sound.h"
00027 #include "autoslope.h"
00028 #include "tunnelbridge_map.h"
00029 #include "strings_func.h"
00030 #include "date_func.h"
00031 #include "clear_func.h"
00032 #include "vehicle_func.h"
00033 #include "sound_func.h"
00034 #include "tunnelbridge.h"
00035 #include "cheat_type.h"
00036 #include "elrail_func.h"
00037 #include "pbs.h"
00038 #include "company_base.h"
00039 #include "newgrf_railtype.h"
00040 #include "object_base.h"
00041 #include "water.h"
00042 #include "company_gui.h"
00043 
00044 #include "table/strings.h"
00045 #include "table/bridge_land.h"
00046 
00047 BridgeSpec _bridge[MAX_BRIDGES]; 
00048 TileIndex _build_tunnel_endtile; 
00049 
00051 static const int BRIDGE_Z_START = 3;
00052 
00054 void ResetBridges()
00055 {
00056   /* First, free sprite table data */
00057   for (BridgeType i = 0; i < MAX_BRIDGES; i++) {
00058     if (_bridge[i].sprite_table != NULL) {
00059       for (BridgePieces j = BRIDGE_PIECE_NORTH; j < BRIDGE_PIECE_INVALID; j++) free(_bridge[i].sprite_table[j]);
00060       free(_bridge[i].sprite_table);
00061     }
00062   }
00063 
00064   /* Then, wipe out current bridges */
00065   memset(&_bridge, 0, sizeof(_bridge));
00066   /* And finally, reinstall default data */
00067   memcpy(&_bridge, &_orig_bridge, sizeof(_orig_bridge));
00068 }
00069 
00076 int CalcBridgeLenCostFactor(int length)
00077 {
00078   if (length < 2) return length;
00079 
00080   length -= 2;
00081   int sum = 2;
00082   for (int delta = 1;; delta++) {
00083     for (int count = 0; count < delta; count++) {
00084       if (length == 0) return sum;
00085       sum += delta;
00086       length--;
00087     }
00088   }
00089 }
00090 
00097 Foundation GetBridgeFoundation(Slope tileh, Axis axis)
00098 {
00099   if (tileh == SLOPE_FLAT ||
00100       ((tileh == SLOPE_NE || tileh == SLOPE_SW) && axis == AXIS_X) ||
00101       ((tileh == SLOPE_NW || tileh == SLOPE_SE) && axis == AXIS_Y)) return FOUNDATION_NONE;
00102 
00103   return (HasSlopeHighestCorner(tileh) ? InclinedFoundation(axis) : FlatteningFoundation(tileh));
00104 }
00105 
00113 bool HasBridgeFlatRamp(Slope tileh, Axis axis)
00114 {
00115   ApplyFoundationToSlope(GetBridgeFoundation(tileh, axis), &tileh);
00116   /* If the foundation slope is flat the bridge has a non-flat ramp and vice versa. */
00117   return (tileh != SLOPE_FLAT);
00118 }
00119 
00120 static inline const PalSpriteID *GetBridgeSpriteTable(int index, BridgePieces table)
00121 {
00122   const BridgeSpec *bridge = GetBridgeSpec(index);
00123   assert(table < BRIDGE_PIECE_INVALID);
00124   if (bridge->sprite_table == NULL || bridge->sprite_table[table] == NULL) {
00125     return _bridge_sprite_table[index][table];
00126   } else {
00127     return bridge->sprite_table[table];
00128   }
00129 }
00130 
00131 
00140 static CommandCost CheckBridgeSlopeNorth(Axis axis, Slope *tileh, int *z)
00141 {
00142   Foundation f = GetBridgeFoundation(*tileh, axis);
00143   *z += ApplyFoundationToSlope(f, tileh);
00144 
00145   Slope valid_inclined = (axis == AXIS_X ? SLOPE_NE : SLOPE_NW);
00146   if ((*tileh != SLOPE_FLAT) && (*tileh != valid_inclined)) return CMD_ERROR;
00147 
00148   if (f == FOUNDATION_NONE) return CommandCost();
00149 
00150   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
00151 }
00152 
00161 static CommandCost CheckBridgeSlopeSouth(Axis axis, Slope *tileh, int *z)
00162 {
00163   Foundation f = GetBridgeFoundation(*tileh, axis);
00164   *z += ApplyFoundationToSlope(f, tileh);
00165 
00166   Slope valid_inclined = (axis == AXIS_X ? SLOPE_SW : SLOPE_SE);
00167   if ((*tileh != SLOPE_FLAT) && (*tileh != valid_inclined)) return CMD_ERROR;
00168 
00169   if (f == FOUNDATION_NONE) return CommandCost();
00170 
00171   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
00172 }
00173 
00180 CommandCost CheckBridgeAvailability(BridgeType bridge_type, uint bridge_len, DoCommandFlag flags)
00181 {
00182   if (flags & DC_QUERY_COST) {
00183     if (bridge_len <= _settings_game.construction.max_bridge_length) return CommandCost();
00184     return_cmd_error(STR_ERROR_BRIDGE_TOO_LONG);
00185   }
00186 
00187   if (bridge_type >= MAX_BRIDGES) return CMD_ERROR;
00188 
00189   const BridgeSpec *b = GetBridgeSpec(bridge_type);
00190   if (b->avail_year > _cur_year) return CMD_ERROR;
00191 
00192   uint max = min(b->max_length, _settings_game.construction.max_bridge_length);
00193 
00194   if (b->min_length > bridge_len) return CMD_ERROR;
00195   if (bridge_len <= max) return CommandCost();
00196   return_cmd_error(STR_ERROR_BRIDGE_TOO_LONG);
00197 }
00198 
00211 CommandCost CmdBuildBridge(TileIndex end_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00212 {
00213   CompanyID company = _current_company;
00214 
00215   RailType railtype = INVALID_RAILTYPE;
00216   RoadTypes roadtypes = ROADTYPES_NONE;
00217 
00218   /* unpack parameters */
00219   BridgeType bridge_type = GB(p2, 0, 8);
00220 
00221   if (!IsValidTile(p1)) return_cmd_error(STR_ERROR_BRIDGE_THROUGH_MAP_BORDER);
00222 
00223   TransportType transport_type = Extract<TransportType, 15, 2>(p2);
00224 
00225   /* type of bridge */
00226   switch (transport_type) {
00227     case TRANSPORT_ROAD:
00228       roadtypes = Extract<RoadTypes, 8, 2>(p2);
00229       if (!HasExactlyOneBit(roadtypes) || !HasRoadTypesAvail(company, roadtypes)) return CMD_ERROR;
00230       break;
00231 
00232     case TRANSPORT_RAIL:
00233       railtype = Extract<RailType, 8, 4>(p2);
00234       if (!ValParamRailtype(railtype)) return CMD_ERROR;
00235       break;
00236 
00237     case TRANSPORT_WATER:
00238       break;
00239 
00240     default:
00241       /* Airports don't have bridges. */
00242       return CMD_ERROR;
00243   }
00244   TileIndex tile_start = p1;
00245   TileIndex tile_end = end_tile;
00246 
00247   if (company == OWNER_DEITY) {
00248     if (transport_type != TRANSPORT_ROAD) return CMD_ERROR;
00249     const Town *town = CalcClosestTownFromTile(tile_start);
00250 
00251     company = OWNER_TOWN;
00252 
00253     /* If we are not within a town, we are not owned by the town */
00254     if (town == NULL || DistanceSquare(tile_start, town->xy) > town->cache.squared_town_zone_radius[HZB_TOWN_EDGE]) {
00255       company = OWNER_NONE;
00256     }
00257   }
00258 
00259   if (tile_start == tile_end) {
00260     return_cmd_error(STR_ERROR_CAN_T_START_AND_END_ON);
00261   }
00262 
00263   Axis direction;
00264   if (TileX(tile_start) == TileX(tile_end)) {
00265     direction = AXIS_Y;
00266   } else if (TileY(tile_start) == TileY(tile_end)) {
00267     direction = AXIS_X;
00268   } else {
00269     return_cmd_error(STR_ERROR_START_AND_END_MUST_BE_IN);
00270   }
00271 
00272   if (tile_end < tile_start) Swap(tile_start, tile_end);
00273 
00274   uint bridge_len = GetTunnelBridgeLength(tile_start, tile_end);
00275   if (transport_type != TRANSPORT_WATER) {
00276     /* set and test bridge length, availability */
00277     CommandCost ret = CheckBridgeAvailability(bridge_type, bridge_len, flags);
00278     if (ret.Failed()) return ret;
00279   } else {
00280     if (bridge_len > _settings_game.construction.max_bridge_length) return_cmd_error(STR_ERROR_BRIDGE_TOO_LONG);
00281   }
00282 
00283   int z_start;
00284   int z_end;
00285   Slope tileh_start = GetTileSlope(tile_start, &z_start);
00286   Slope tileh_end = GetTileSlope(tile_end, &z_end);
00287   bool pbs_reservation = false;
00288 
00289   CommandCost terraform_cost_north = CheckBridgeSlopeNorth(direction, &tileh_start, &z_start);
00290   CommandCost terraform_cost_south = CheckBridgeSlopeSouth(direction, &tileh_end,   &z_end);
00291 
00292   /* Aqueducts can't be built of flat land. */
00293   if (transport_type == TRANSPORT_WATER && (tileh_start == SLOPE_FLAT || tileh_end == SLOPE_FLAT)) return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00294   if (z_start != z_end) return_cmd_error(STR_ERROR_BRIDGEHEADS_NOT_SAME_HEIGHT);
00295 
00296   CommandCost cost(EXPENSES_CONSTRUCTION);
00297   Owner owner;
00298   if (IsBridgeTile(tile_start) && IsBridgeTile(tile_end) &&
00299       GetOtherBridgeEnd(tile_start) == tile_end &&
00300       GetTunnelBridgeTransportType(tile_start) == transport_type) {
00301     /* Replace a current bridge. */
00302 
00303     /* If this is a railway bridge, make sure the railtypes match. */
00304     if (transport_type == TRANSPORT_RAIL && GetRailType(tile_start) != railtype) {
00305       return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00306     }
00307 
00308     /* Do not replace town bridges with lower speed bridges, unless in scenario editor. */
00309     if (!(flags & DC_QUERY_COST) && IsTileOwner(tile_start, OWNER_TOWN) &&
00310         GetBridgeSpec(bridge_type)->speed < GetBridgeSpec(GetBridgeType(tile_start))->speed &&
00311         _game_mode != GM_EDITOR) {
00312       Town *t = ClosestTownFromTile(tile_start, UINT_MAX);
00313 
00314       if (t == NULL) {
00315         return CMD_ERROR;
00316       } else {
00317         SetDParam(0, t->index);
00318         return_cmd_error(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS);
00319       }
00320     }
00321 
00322     /* Do not replace the bridge with the same bridge type. */
00323     if (!(flags & DC_QUERY_COST) && (bridge_type == GetBridgeType(tile_start)) && (transport_type != TRANSPORT_ROAD || (roadtypes & ~GetRoadTypes(tile_start)) == 0)) {
00324       return_cmd_error(STR_ERROR_ALREADY_BUILT);
00325     }
00326 
00327     /* Do not allow replacing another company's bridges. */
00328     if (!IsTileOwner(tile_start, company) && !IsTileOwner(tile_start, OWNER_TOWN)) {
00329       return_cmd_error(STR_ERROR_AREA_IS_OWNED_BY_ANOTHER);
00330     }
00331 
00332     cost.AddCost((bridge_len + 1) * _price[PR_CLEAR_BRIDGE]); // The cost of clearing the current bridge.
00333     owner = GetTileOwner(tile_start);
00334 
00335     switch (transport_type) {
00336       case TRANSPORT_RAIL:
00337         /* Keep the reservation, the path stays valid. */
00338         pbs_reservation = HasTunnelBridgeReservation(tile_start);
00339         break;
00340 
00341       case TRANSPORT_ROAD:
00342         /* Do not remove road types when upgrading a bridge */
00343         roadtypes |= GetRoadTypes(tile_start);
00344         break;
00345 
00346       default: break;
00347     }
00348   } else {
00349     /* Build a new bridge. */
00350 
00351     bool allow_on_slopes = (_settings_game.construction.build_on_slopes && transport_type != TRANSPORT_WATER);
00352 
00353     /* Try and clear the start landscape */
00354     CommandCost ret = DoCommand(tile_start, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00355     if (ret.Failed()) return ret;
00356     cost = ret;
00357 
00358     if (terraform_cost_north.Failed() || (terraform_cost_north.GetCost() != 0 && !allow_on_slopes)) return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00359     cost.AddCost(terraform_cost_north);
00360 
00361     /* Try and clear the end landscape */
00362     ret = DoCommand(tile_end, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00363     if (ret.Failed()) return ret;
00364     cost.AddCost(ret);
00365 
00366     /* false - end tile slope check */
00367     if (terraform_cost_south.Failed() || (terraform_cost_south.GetCost() != 0 && !allow_on_slopes)) return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00368     cost.AddCost(terraform_cost_south);
00369 
00370     const TileIndex heads[] = {tile_start, tile_end};
00371     for (int i = 0; i < 2; i++) {
00372       if (MayHaveBridgeAbove(heads[i])) {
00373         if (IsBridgeAbove(heads[i])) {
00374           TileIndex north_head = GetNorthernBridgeEnd(heads[i]);
00375 
00376           if (direction == GetBridgeAxis(heads[i])) return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00377 
00378           if (z_start + 1 == GetBridgeHeight(north_head)) {
00379             return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00380           }
00381         }
00382       }
00383     }
00384 
00385     TileIndexDiff delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
00386     for (TileIndex tile = tile_start + delta; tile != tile_end; tile += delta) {
00387       if (GetTileMaxZ(tile) > z_start) return_cmd_error(STR_ERROR_BRIDGE_TOO_LOW_FOR_TERRAIN);
00388 
00389       if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
00390         /* Disallow crossing bridges for the time being */
00391         return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00392       }
00393 
00394       switch (GetTileType(tile)) {
00395         case MP_WATER:
00396           if (!IsWater(tile) && !IsCoast(tile)) goto not_valid_below;
00397           break;
00398 
00399         case MP_RAILWAY:
00400           if (!IsPlainRail(tile)) goto not_valid_below;
00401           break;
00402 
00403         case MP_ROAD:
00404           if (IsRoadDepot(tile)) goto not_valid_below;
00405           break;
00406 
00407         case MP_TUNNELBRIDGE:
00408           if (IsTunnel(tile)) break;
00409           if (direction == DiagDirToAxis(GetTunnelBridgeDirection(tile))) goto not_valid_below;
00410           if (z_start < GetBridgeHeight(tile)) goto not_valid_below;
00411           break;
00412 
00413         case MP_OBJECT: {
00414           const ObjectSpec *spec = ObjectSpec::GetByTile(tile);
00415           if ((spec->flags & OBJECT_FLAG_ALLOW_UNDER_BRIDGE) == 0) goto not_valid_below;
00416           if (GetTileMaxZ(tile) + spec->height > z_start) goto not_valid_below;
00417           break;
00418         }
00419 
00420         case MP_CLEAR:
00421           break;
00422 
00423         default:
00424   not_valid_below:;
00425           /* try and clear the middle landscape */
00426           ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00427           if (ret.Failed()) return ret;
00428           cost.AddCost(ret);
00429           break;
00430       }
00431 
00432       if (flags & DC_EXEC) {
00433         /* We do this here because when replacing a bridge with another
00434          * type calling SetBridgeMiddle isn't needed. After all, the
00435          * tile already has the has_bridge_above bits set. */
00436         SetBridgeMiddle(tile, direction);
00437       }
00438     }
00439 
00440     owner = company;
00441   }
00442 
00443   /* do the drill? */
00444   if (flags & DC_EXEC) {
00445     DiagDirection dir = AxisToDiagDir(direction);
00446 
00447     Company *c = Company::GetIfValid(owner);
00448     switch (transport_type) {
00449       case TRANSPORT_RAIL:
00450         /* Add to company infrastructure count if building a new bridge. */
00451         if (!IsBridgeTile(tile_start) && c != NULL) c->infrastructure.rail[railtype] += (bridge_len + 2) * TUNNELBRIDGE_TRACKBIT_FACTOR;
00452         MakeRailBridgeRamp(tile_start, owner, bridge_type, dir,                 railtype);
00453         MakeRailBridgeRamp(tile_end,   owner, bridge_type, ReverseDiagDir(dir), railtype);
00454         SetTunnelBridgeReservation(tile_start, pbs_reservation);
00455         SetTunnelBridgeReservation(tile_end,   pbs_reservation);
00456         break;
00457 
00458       case TRANSPORT_ROAD: {
00459         RoadTypes prev_roadtypes = IsBridgeTile(tile_start) ? GetRoadTypes(tile_start) : ROADTYPES_NONE;
00460         if (c != NULL) {
00461           /* Add all new road types to the company infrastructure counter. */
00462           RoadType new_rt;
00463           FOR_EACH_SET_ROADTYPE(new_rt, roadtypes ^ prev_roadtypes) {
00464             /* A full diagonal road tile has two road bits. */
00465             Company::Get(owner)->infrastructure.road[new_rt] += (bridge_len + 2) * 2 * TUNNELBRIDGE_TRACKBIT_FACTOR;
00466           }
00467         }
00468         Owner owner_road = owner;
00469         Owner owner_tram = owner;
00470         if (HasBit(prev_roadtypes, ROADTYPE_ROAD)) owner_road = GetRoadOwner(tile_start, ROADTYPE_ROAD);
00471         if (HasBit(prev_roadtypes, ROADTYPE_TRAM)) owner_tram = GetRoadOwner(tile_start, ROADTYPE_TRAM);
00472         MakeRoadBridgeRamp(tile_start, owner, owner_road, owner_tram, bridge_type, dir,                 roadtypes);
00473         MakeRoadBridgeRamp(tile_end,   owner, owner_road, owner_tram, bridge_type, ReverseDiagDir(dir), roadtypes);
00474         break;
00475       }
00476 
00477       case TRANSPORT_WATER:
00478         if (!IsBridgeTile(tile_start) && c != NULL) c->infrastructure.water += (bridge_len + 2) * TUNNELBRIDGE_TRACKBIT_FACTOR;
00479         MakeAqueductBridgeRamp(tile_start, owner, dir);
00480         MakeAqueductBridgeRamp(tile_end,   owner, ReverseDiagDir(dir));
00481         break;
00482 
00483       default:
00484         NOT_REACHED();
00485     }
00486 
00487     /* Mark all tiles dirty */
00488     TileIndexDiff delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
00489     for (TileIndex tile = tile_start; tile <= tile_end; tile += delta) {
00490       MarkTileDirtyByTile(tile);
00491     }
00492     DirtyCompanyInfrastructureWindows(owner);
00493   }
00494 
00495   if ((flags & DC_EXEC) && transport_type == TRANSPORT_RAIL) {
00496     Track track = AxisToTrack(direction);
00497     AddSideToSignalBuffer(tile_start, INVALID_DIAGDIR, company);
00498     YapfNotifyTrackLayoutChange(tile_start, track);
00499   }
00500 
00501   /* for human player that builds the bridge he gets a selection to choose from bridges (DC_QUERY_COST)
00502    * It's unnecessary to execute this command every time for every bridge. So it is done only
00503    * and cost is computed in "bridge_gui.c". For AI, Towns this has to be of course calculated
00504    */
00505   Company *c = Company::GetIfValid(company);
00506   if (!(flags & DC_QUERY_COST) || (c != NULL && c->is_ai)) {
00507     bridge_len += 2; // begin and end tiles/ramps
00508 
00509     switch (transport_type) {
00510       case TRANSPORT_ROAD: cost.AddCost(bridge_len * _price[PR_BUILD_ROAD] * 2 * CountBits(roadtypes)); break;
00511       case TRANSPORT_RAIL: cost.AddCost(bridge_len * RailBuildCost(railtype)); break;
00512       default: break;
00513     }
00514 
00515     if (c != NULL) bridge_len = CalcBridgeLenCostFactor(bridge_len);
00516 
00517     if (transport_type != TRANSPORT_WATER) {
00518       cost.AddCost((int64)bridge_len * _price[PR_BUILD_BRIDGE] * GetBridgeSpec(bridge_type)->price >> 8);
00519     } else {
00520       /* Aqueducts use a separate base cost. */
00521       cost.AddCost((int64)bridge_len * _price[PR_BUILD_AQUEDUCT]);
00522     }
00523 
00524   }
00525 
00526   return cost;
00527 }
00528 
00529 
00540 CommandCost CmdBuildTunnel(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00541 {
00542   CompanyID company = _current_company;
00543 
00544   TransportType transport_type = Extract<TransportType, 8, 2>(p1);
00545 
00546   RailType railtype = INVALID_RAILTYPE;
00547   RoadTypes rts = ROADTYPES_NONE;
00548   _build_tunnel_endtile = 0;
00549   switch (transport_type) {
00550     case TRANSPORT_RAIL:
00551       railtype = Extract<RailType, 0, 4>(p1);
00552       if (!ValParamRailtype(railtype)) return CMD_ERROR;
00553       break;
00554 
00555     case TRANSPORT_ROAD:
00556       rts = Extract<RoadTypes, 0, 2>(p1);
00557       if (!HasExactlyOneBit(rts) || !HasRoadTypesAvail(company, rts)) return CMD_ERROR;
00558       break;
00559 
00560     default: return CMD_ERROR;
00561   }
00562 
00563   if (company == OWNER_DEITY) {
00564     if (transport_type != TRANSPORT_ROAD) return CMD_ERROR;
00565     const Town *town = CalcClosestTownFromTile(start_tile);
00566 
00567     company = OWNER_TOWN;
00568 
00569     /* If we are not within a town, we are not owned by the town */
00570     if (town == NULL || DistanceSquare(start_tile, town->xy) > town->cache.squared_town_zone_radius[HZB_TOWN_EDGE]) {
00571       company = OWNER_NONE;
00572     }
00573   }
00574 
00575   int start_z;
00576   int end_z;
00577   Slope start_tileh = GetTileSlope(start_tile, &start_z);
00578   DiagDirection direction = GetInclinedSlopeDirection(start_tileh);
00579   if (direction == INVALID_DIAGDIR) return_cmd_error(STR_ERROR_SITE_UNSUITABLE_FOR_TUNNEL);
00580 
00581   if (HasTileWaterGround(start_tile)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
00582 
00583   CommandCost ret = DoCommand(start_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00584   if (ret.Failed()) return ret;
00585 
00586   /* XXX - do NOT change 'ret' in the loop, as it is used as the price
00587    * for the clearing of the entrance of the tunnel. Assigning it to
00588    * cost before the loop will yield different costs depending on start-
00589    * position, because of increased-cost-by-length: 'cost += cost >> 3' */
00590 
00591   TileIndexDiff delta = TileOffsByDiagDir(direction);
00592   DiagDirection tunnel_in_way_dir;
00593   if (DiagDirToAxis(direction) == AXIS_Y) {
00594     tunnel_in_way_dir = (TileX(start_tile) < (MapMaxX() / 2)) ? DIAGDIR_SW : DIAGDIR_NE;
00595   } else {
00596     tunnel_in_way_dir = (TileY(start_tile) < (MapMaxX() / 2)) ? DIAGDIR_SE : DIAGDIR_NW;
00597   }
00598 
00599   TileIndex end_tile = start_tile;
00600 
00601   /* Tile shift coefficient. Will decrease for very long tunnels to avoid exponential growth of price*/
00602   int tiles_coef = 3;
00603   /* Number of tiles from start of tunnel */
00604   int tiles = 0;
00605   /* Number of tiles at which the cost increase coefficient per tile is halved */
00606   int tiles_bump = 25;
00607 
00608   CommandCost cost(EXPENSES_CONSTRUCTION);
00609   Slope end_tileh;
00610   for (;;) {
00611     end_tile += delta;
00612     if (!IsValidTile(end_tile)) return_cmd_error(STR_ERROR_TUNNEL_THROUGH_MAP_BORDER);
00613     end_tileh = GetTileSlope(end_tile, &end_z);
00614 
00615     if (start_z == end_z) break;
00616 
00617     if (!_cheats.crossing_tunnels.value && IsTunnelInWayDir(end_tile, start_z, tunnel_in_way_dir)) {
00618       return_cmd_error(STR_ERROR_ANOTHER_TUNNEL_IN_THE_WAY);
00619     }
00620 
00621     tiles++;
00622     if (tiles == tiles_bump) {
00623       tiles_coef++;
00624       tiles_bump *= 2;
00625     }
00626 
00627     cost.AddCost(_price[PR_BUILD_TUNNEL]);
00628     cost.AddCost(cost.GetCost() >> tiles_coef); // add a multiplier for longer tunnels
00629   }
00630 
00631   /* Add the cost of the entrance */
00632   cost.AddCost(_price[PR_BUILD_TUNNEL]);
00633   cost.AddCost(ret);
00634 
00635   /* if the command fails from here on we want the end tile to be highlighted */
00636   _build_tunnel_endtile = end_tile;
00637 
00638   if (tiles > _settings_game.construction.max_tunnel_length) return_cmd_error(STR_ERROR_TUNNEL_TOO_LONG);
00639 
00640   if (HasTileWaterGround(end_tile)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
00641 
00642   /* Clear the tile in any case */
00643   ret = DoCommand(end_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00644   if (ret.Failed()) return_cmd_error(STR_ERROR_UNABLE_TO_EXCAVATE_LAND);
00645   cost.AddCost(ret);
00646 
00647   /* slope of end tile must be complementary to the slope of the start tile */
00648   if (end_tileh != ComplementSlope(start_tileh)) {
00649     /* Mark the tile as already cleared for the terraform command.
00650      * Do this for all tiles (like trees), not only objects. */
00651     ClearedObjectArea *coa = FindClearedObject(end_tile);
00652     if (coa == NULL) {
00653       coa = _cleared_object_areas.Append();
00654       coa->first_tile = end_tile;
00655       coa->area = TileArea(end_tile, 1, 1);
00656     }
00657 
00658     /* Hide the tile from the terraforming command */
00659     TileIndex old_first_tile = coa->first_tile;
00660     coa->first_tile = INVALID_TILE;
00661     ret = DoCommand(end_tile, end_tileh & start_tileh, 0, flags, CMD_TERRAFORM_LAND);
00662     coa->first_tile = old_first_tile;
00663     if (ret.Failed()) return_cmd_error(STR_ERROR_UNABLE_TO_EXCAVATE_LAND);
00664     cost.AddCost(ret);
00665   }
00666   cost.AddCost(_price[PR_BUILD_TUNNEL]);
00667 
00668   /* Pay for the rail/road in the tunnel including entrances */
00669   switch (transport_type) {
00670     case TRANSPORT_ROAD: cost.AddCost((tiles + 2) * _price[PR_BUILD_ROAD] * 2); break;
00671     case TRANSPORT_RAIL: cost.AddCost((tiles + 2) * RailBuildCost(railtype)); break;
00672     default: break;
00673   }
00674 
00675   if (flags & DC_EXEC) {
00676     Company *c = Company::GetIfValid(company);
00677     uint num_pieces = (tiles + 2) * TUNNELBRIDGE_TRACKBIT_FACTOR;
00678     if (transport_type == TRANSPORT_RAIL) {
00679       if (!IsTunnelTile(start_tile) && c != NULL) c->infrastructure.rail[railtype] += num_pieces;
00680       MakeRailTunnel(start_tile, company, direction,                 railtype);
00681       MakeRailTunnel(end_tile,   company, ReverseDiagDir(direction), railtype);
00682       AddSideToSignalBuffer(start_tile, INVALID_DIAGDIR, company);
00683       YapfNotifyTrackLayoutChange(start_tile, DiagDirToDiagTrack(direction));
00684     } else {
00685       if (c != NULL) {
00686         RoadType rt;
00687         FOR_EACH_SET_ROADTYPE(rt, rts ^ (IsTunnelTile(start_tile) ? GetRoadTypes(start_tile) : ROADTYPES_NONE)) {
00688           c->infrastructure.road[rt] += num_pieces * 2; // A full diagonal road has two road bits.
00689         }
00690       }
00691       MakeRoadTunnel(start_tile, company, direction,                 rts);
00692       MakeRoadTunnel(end_tile,   company, ReverseDiagDir(direction), rts);
00693     }
00694     DirtyCompanyInfrastructureWindows(company);
00695   }
00696 
00697   return cost;
00698 }
00699 
00700 
00706 static inline CommandCost CheckAllowRemoveTunnelBridge(TileIndex tile)
00707 {
00708   /* Floods can remove anything as well as the scenario editor */
00709   if (_current_company == OWNER_WATER || _game_mode == GM_EDITOR) return CommandCost();
00710 
00711   switch (GetTunnelBridgeTransportType(tile)) {
00712     case TRANSPORT_ROAD: {
00713       RoadTypes rts = GetRoadTypes(tile);
00714       Owner road_owner = _current_company;
00715       Owner tram_owner = _current_company;
00716 
00717       if (HasBit(rts, ROADTYPE_ROAD)) road_owner = GetRoadOwner(tile, ROADTYPE_ROAD);
00718       if (HasBit(rts, ROADTYPE_TRAM)) tram_owner = GetRoadOwner(tile, ROADTYPE_TRAM);
00719 
00720       /* We can remove unowned road and if the town allows it */
00721       if (road_owner == OWNER_TOWN && _current_company != OWNER_TOWN && !(_settings_game.construction.extra_dynamite || _cheats.magic_bulldozer.value)) {
00722         /* Town does not allow */
00723         return CheckTileOwnership(tile);
00724       }
00725       if (road_owner == OWNER_NONE || road_owner == OWNER_TOWN) road_owner = _current_company;
00726       if (tram_owner == OWNER_NONE) tram_owner = _current_company;
00727 
00728       CommandCost ret = CheckOwnership(road_owner, tile);
00729       if (ret.Succeeded()) ret = CheckOwnership(tram_owner, tile);
00730       return ret;
00731     }
00732 
00733     case TRANSPORT_RAIL:
00734       return CheckOwnership(GetTileOwner(tile));
00735 
00736     case TRANSPORT_WATER: {
00737       /* Always allow to remove aqueducts without owner. */
00738       Owner aqueduct_owner = GetTileOwner(tile);
00739       if (aqueduct_owner == OWNER_NONE) aqueduct_owner = _current_company;
00740       return CheckOwnership(aqueduct_owner);
00741     }
00742 
00743     default: NOT_REACHED();
00744   }
00745 }
00746 
00753 static CommandCost DoClearTunnel(TileIndex tile, DoCommandFlag flags)
00754 {
00755   CommandCost ret = CheckAllowRemoveTunnelBridge(tile);
00756   if (ret.Failed()) return ret;
00757 
00758   TileIndex endtile = GetOtherTunnelEnd(tile);
00759 
00760   ret = TunnelBridgeIsFree(tile, endtile);
00761   if (ret.Failed()) return ret;
00762 
00763   _build_tunnel_endtile = endtile;
00764 
00765   Town *t = NULL;
00766   if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
00767     t = ClosestTownFromTile(tile, UINT_MAX); // town penalty rating
00768 
00769     /* Check if you are allowed to remove the tunnel owned by a town
00770      * Removal depends on difficulty settings */
00771     CommandCost ret = CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE);
00772     if (ret.Failed()) return ret;
00773   }
00774 
00775   /* checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
00776    * you have a "Poor" (0) town rating */
00777   if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
00778     ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM, flags);
00779   }
00780 
00781   uint len = GetTunnelBridgeLength(tile, endtile) + 2; // Don't forget the end tiles.
00782 
00783   if (flags & DC_EXEC) {
00784     if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {
00785       /* We first need to request values before calling DoClearSquare */
00786       DiagDirection dir = GetTunnelBridgeDirection(tile);
00787       Track track = DiagDirToDiagTrack(dir);
00788       Owner owner = GetTileOwner(tile);
00789 
00790       Train *v = NULL;
00791       if (HasTunnelBridgeReservation(tile)) {
00792         v = GetTrainForReservation(tile, track);
00793         if (v != NULL) FreeTrainTrackReservation(v);
00794       }
00795 
00796       if (Company::IsValidID(owner)) {
00797         Company::Get(owner)->infrastructure.rail[GetRailType(tile)] -= len * TUNNELBRIDGE_TRACKBIT_FACTOR;
00798         DirtyCompanyInfrastructureWindows(owner);
00799       }
00800 
00801       DoClearSquare(tile);
00802       DoClearSquare(endtile);
00803 
00804       /* cannot use INVALID_DIAGDIR for signal update because the tunnel doesn't exist anymore */
00805       AddSideToSignalBuffer(tile,    ReverseDiagDir(dir), owner);
00806       AddSideToSignalBuffer(endtile, dir,                 owner);
00807 
00808       YapfNotifyTrackLayoutChange(tile,    track);
00809       YapfNotifyTrackLayoutChange(endtile, track);
00810 
00811       if (v != NULL) TryPathReserve(v);
00812     } else {
00813       RoadType rt;
00814       FOR_EACH_SET_ROADTYPE(rt, GetRoadTypes(tile)) {
00815         /* A full diagonal road tile has two road bits. */
00816         Company *c = Company::GetIfValid(GetRoadOwner(tile, rt));
00817         if (c != NULL) {
00818           c->infrastructure.road[rt] -= len * 2 * TUNNELBRIDGE_TRACKBIT_FACTOR;
00819           DirtyCompanyInfrastructureWindows(c->index);
00820         }
00821       }
00822 
00823       DoClearSquare(tile);
00824       DoClearSquare(endtile);
00825     }
00826   }
00827   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_TUNNEL] * len);
00828 }
00829 
00830 
00837 static CommandCost DoClearBridge(TileIndex tile, DoCommandFlag flags)
00838 {
00839   CommandCost ret = CheckAllowRemoveTunnelBridge(tile);
00840   if (ret.Failed()) return ret;
00841 
00842   TileIndex endtile = GetOtherBridgeEnd(tile);
00843 
00844   ret = TunnelBridgeIsFree(tile, endtile);
00845   if (ret.Failed()) return ret;
00846 
00847   DiagDirection direction = GetTunnelBridgeDirection(tile);
00848   TileIndexDiff delta = TileOffsByDiagDir(direction);
00849 
00850   Town *t = NULL;
00851   if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
00852     t = ClosestTownFromTile(tile, UINT_MAX); // town penalty rating
00853 
00854     /* Check if you are allowed to remove the bridge owned by a town
00855      * Removal depends on difficulty settings */
00856     CommandCost ret = CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE);
00857     if (ret.Failed()) return ret;
00858   }
00859 
00860   /* checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
00861    * you have a "Poor" (0) town rating */
00862   if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
00863     ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM, flags);
00864   }
00865 
00866   Money base_cost = (GetTunnelBridgeTransportType(tile) != TRANSPORT_WATER) ? _price[PR_CLEAR_BRIDGE] : _price[PR_CLEAR_AQUEDUCT];
00867   uint len = GetTunnelBridgeLength(tile, endtile) + 2; // Don't forget the end tiles.
00868 
00869   if (flags & DC_EXEC) {
00870     /* read this value before actual removal of bridge */
00871     bool rail = GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL;
00872     Owner owner = GetTileOwner(tile);
00873     int height = GetBridgeHeight(tile);
00874     Train *v = NULL;
00875 
00876     if (rail && HasTunnelBridgeReservation(tile)) {
00877       v = GetTrainForReservation(tile, DiagDirToDiagTrack(direction));
00878       if (v != NULL) FreeTrainTrackReservation(v);
00879     }
00880 
00881     /* Update company infrastructure counts. */
00882     if (rail) {
00883       if (Company::IsValidID(owner)) Company::Get(owner)->infrastructure.rail[GetRailType(tile)] -= len * TUNNELBRIDGE_TRACKBIT_FACTOR;
00884     } else if (GetTunnelBridgeTransportType(tile) == TRANSPORT_ROAD) {
00885       RoadType rt;
00886       FOR_EACH_SET_ROADTYPE(rt, GetRoadTypes(tile)) {
00887         Company *c = Company::GetIfValid(GetRoadOwner(tile, rt));
00888         if (c != NULL) {
00889           /* A full diagonal road tile has two road bits. */
00890           c->infrastructure.road[rt] -= len * 2 * TUNNELBRIDGE_TRACKBIT_FACTOR;
00891           DirtyCompanyInfrastructureWindows(c->index);
00892         }
00893       }
00894     } else { // Aqueduct
00895       if (Company::IsValidID(owner)) Company::Get(owner)->infrastructure.water -= len * TUNNELBRIDGE_TRACKBIT_FACTOR;
00896     }
00897     DirtyCompanyInfrastructureWindows(owner);
00898 
00899     DoClearSquare(tile);
00900     DoClearSquare(endtile);
00901     for (TileIndex c = tile + delta; c != endtile; c += delta) {
00902       /* do not let trees appear from 'nowhere' after removing bridge */
00903       if (IsNormalRoadTile(c) && GetRoadside(c) == ROADSIDE_TREES) {
00904         int minz = GetTileMaxZ(c) + 3;
00905         if (height < minz) SetRoadside(c, ROADSIDE_PAVED);
00906       }
00907       ClearBridgeMiddle(c);
00908       MarkTileDirtyByTile(c);
00909     }
00910 
00911     if (rail) {
00912       /* cannot use INVALID_DIAGDIR for signal update because the bridge doesn't exist anymore */
00913       AddSideToSignalBuffer(tile,    ReverseDiagDir(direction), owner);
00914       AddSideToSignalBuffer(endtile, direction,                 owner);
00915 
00916       Track track = DiagDirToDiagTrack(direction);
00917       YapfNotifyTrackLayoutChange(tile,    track);
00918       YapfNotifyTrackLayoutChange(endtile, track);
00919 
00920       if (v != NULL) TryPathReserve(v, true);
00921     }
00922   }
00923 
00924   return CommandCost(EXPENSES_CONSTRUCTION, len * base_cost);
00925 }
00926 
00933 static CommandCost ClearTile_TunnelBridge(TileIndex tile, DoCommandFlag flags)
00934 {
00935   if (IsTunnel(tile)) {
00936     if (flags & DC_AUTO) return_cmd_error(STR_ERROR_MUST_DEMOLISH_TUNNEL_FIRST);
00937     return DoClearTunnel(tile, flags);
00938   } else { // IsBridge(tile)
00939     if (flags & DC_AUTO) return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00940     return DoClearBridge(tile, flags);
00941   }
00942 }
00943 
00954 static inline void DrawPillar(const PalSpriteID *psid, int x, int y, int z, int w, int h, const SubSprite *subsprite)
00955 {
00956   static const int PILLAR_Z_OFFSET = TILE_HEIGHT - BRIDGE_Z_START; 
00957   AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, w, h, BB_HEIGHT_UNDER_BRIDGE - PILLAR_Z_OFFSET, z, IsTransparencySet(TO_BRIDGES), 0, 0, -PILLAR_Z_OFFSET, subsprite);
00958 }
00959 
00971 static int DrawPillarColumn(int z_bottom, int z_top, const PalSpriteID *psid, int x, int y, int w, int h)
00972 {
00973   int cur_z;
00974   for (cur_z = z_top; cur_z >= z_bottom; cur_z -= TILE_HEIGHT) {
00975     DrawPillar(psid, x, y, cur_z, w, h, NULL);
00976   }
00977   return cur_z;
00978 }
00979 
00991 static void DrawBridgePillars(const PalSpriteID *psid, const TileInfo *ti, Axis axis, bool drawfarpillar, int x, int y, int z_bridge)
00992 {
00993   static const int bounding_box_size[2]  = {16, 2}; 
00994   static const int back_pillar_offset[2] = { 0, 9}; 
00995 
00996   static const int INF = 1000; 
00997   static const SubSprite half_pillar_sub_sprite[2][2] = {
00998     { {  -14, -INF, INF, INF }, { -INF, -INF, -15, INF } }, // X axis, north and south
00999     { { -INF, -INF,  15, INF }, {   16, -INF, INF, INF } }, // Y axis, north and south
01000   };
01001 
01002   if (psid->sprite == 0) return;
01003 
01004   /* Determine ground height under pillars */
01005   DiagDirection south_dir = AxisToDiagDir(axis);
01006   int z_front_north = ti->z;
01007   int z_back_north = ti->z;
01008   int z_front_south = ti->z;
01009   int z_back_south = ti->z;
01010   GetSlopePixelZOnEdge(ti->tileh, south_dir, &z_front_south, &z_back_south);
01011   GetSlopePixelZOnEdge(ti->tileh, ReverseDiagDir(south_dir), &z_front_north, &z_back_north);
01012 
01013   /* Shared height of pillars */
01014   int z_front = max(z_front_north, z_front_south);
01015   int z_back = max(z_back_north, z_back_south);
01016 
01017   /* x and y size of bounding-box of pillars */
01018   int w = bounding_box_size[axis];
01019   int h = bounding_box_size[OtherAxis(axis)];
01020   /* sprite position of back facing pillar */
01021   int x_back = x - back_pillar_offset[axis];
01022   int y_back = y - back_pillar_offset[OtherAxis(axis)];
01023 
01024   /* Draw front pillars */
01025   int bottom_z = DrawPillarColumn(z_front, z_bridge, psid, x, y, w, h);
01026   if (z_front_north < z_front) DrawPillar(psid, x, y, bottom_z, w, h, &half_pillar_sub_sprite[axis][0]);
01027   if (z_front_south < z_front) DrawPillar(psid, x, y, bottom_z, w, h, &half_pillar_sub_sprite[axis][1]);
01028 
01029   /* Draw back pillars, skip top two parts, which are hidden by the bridge */
01030   int z_bridge_back = z_bridge - 2 * (int)TILE_HEIGHT;
01031   if (drawfarpillar && (z_back_north <= z_bridge_back || z_back_south <= z_bridge_back)) {
01032     bottom_z = DrawPillarColumn(z_back, z_bridge_back, psid, x_back, y_back, w, h);
01033     if (z_back_north < z_back) DrawPillar(psid, x_back, y_back, bottom_z, w, h, &half_pillar_sub_sprite[axis][0]);
01034     if (z_back_south < z_back) DrawPillar(psid, x_back, y_back, bottom_z, w, h, &half_pillar_sub_sprite[axis][1]);
01035   }
01036 }
01037 
01047 static void DrawBridgeTramBits(int x, int y, int z, int offset, bool overlay, bool head)
01048 {
01049   static const SpriteID tram_offsets[2][6] = { { 107, 108, 109, 110, 111, 112 }, { 4, 5, 15, 16, 17, 18 } };
01050   static const SpriteID back_offsets[6]    =   {  95,  96,  99, 102, 100, 101 };
01051   static const SpriteID front_offsets[6]   =   {  97,  98, 103, 106, 104, 105 };
01052 
01053   static const uint size_x[6] = {  1, 16, 16,  1, 16,  1 };
01054   static const uint size_y[6] = { 16,  1,  1, 16,  1, 16 };
01055   static const uint front_bb_offset_x[6] = { 15,  0,  0, 15,  0, 15 };
01056   static const uint front_bb_offset_y[6] = {  0, 15, 15,  0, 15,  0 };
01057 
01058   /* The sprites under the vehicles are drawn as SpriteCombine. StartSpriteCombine() has already been called
01059    * The bounding boxes here are the same as for bridge front/roof */
01060   if (head || !IsInvisibilitySet(TO_BRIDGES)) {
01061     AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + tram_offsets[overlay][offset], PAL_NONE,
01062       x, y, size_x[offset], size_y[offset], 0x28, z,
01063       !head && IsTransparencySet(TO_BRIDGES));
01064   }
01065 
01066   /* Do not draw catenary if it is set invisible */
01067   if (!IsInvisibilitySet(TO_CATENARY)) {
01068     AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + back_offsets[offset], PAL_NONE,
01069       x, y, size_x[offset], size_y[offset], 0x28, z,
01070       IsTransparencySet(TO_CATENARY));
01071   }
01072 
01073   /* Start a new SpriteCombine for the front part */
01074   EndSpriteCombine();
01075   StartSpriteCombine();
01076 
01077   /* For sloped sprites the bounding box needs to be higher, as the pylons stop on a higher point */
01078   if (!IsInvisibilitySet(TO_CATENARY)) {
01079     AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + front_offsets[offset], PAL_NONE,
01080       x, y, size_x[offset] + front_bb_offset_x[offset], size_y[offset] + front_bb_offset_y[offset], 0x28, z,
01081       IsTransparencySet(TO_CATENARY), front_bb_offset_x[offset], front_bb_offset_y[offset]);
01082   }
01083 }
01084 
01098 static void DrawTile_TunnelBridge(TileInfo *ti)
01099 {
01100   TransportType transport_type = GetTunnelBridgeTransportType(ti->tile);
01101   DiagDirection tunnelbridge_direction = GetTunnelBridgeDirection(ti->tile);
01102 
01103   if (IsTunnel(ti->tile)) {
01104     /* Front view of tunnel bounding boxes:
01105      *
01106      *   122223  <- BB_Z_SEPARATOR
01107      *   1    3
01108      *   1    3                1,3 = empty helper BB
01109      *   1    3                  2 = SpriteCombine of tunnel-roof and catenary (tram & elrail)
01110      *
01111      */
01112 
01113     static const int _tunnel_BB[4][12] = {
01114       /*  tunnnel-roof  |  Z-separator  | tram-catenary
01115        * w  h  bb_x bb_y| x   y   w   h |bb_x bb_y w h */
01116       {  1,  0, -15, -14,  0, 15, 16,  1, 0, 1, 16, 15 }, // NE
01117       {  0,  1, -14, -15, 15,  0,  1, 16, 1, 0, 15, 16 }, // SE
01118       {  1,  0, -15, -14,  0, 15, 16,  1, 0, 1, 16, 15 }, // SW
01119       {  0,  1, -14, -15, 15,  0,  1, 16, 1, 0, 15, 16 }, // NW
01120     };
01121     const int *BB_data = _tunnel_BB[tunnelbridge_direction];
01122 
01123     bool catenary = false;
01124 
01125     SpriteID image;
01126     SpriteID railtype_overlay = 0;
01127     if (transport_type == TRANSPORT_RAIL) {
01128       const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
01129       image = rti->base_sprites.tunnel;
01130       if (rti->UsesOverlay()) {
01131         /* Check if the railtype has custom tunnel portals. */
01132         railtype_overlay = GetCustomRailSprite(rti, ti->tile, RTSG_TUNNEL_PORTAL);
01133         if (railtype_overlay != 0) image = SPR_RAILTYPE_TUNNEL_BASE; // Draw blank grass tunnel base.
01134       }
01135     } else {
01136       image = SPR_TUNNEL_ENTRY_REAR_ROAD;
01137     }
01138 
01139     if (HasTunnelBridgeSnowOrDesert(ti->tile)) image += railtype_overlay != 0 ? 8 : 32;
01140 
01141     image += tunnelbridge_direction * 2;
01142     DrawGroundSprite(image, PAL_NONE);
01143 
01144     if (transport_type == TRANSPORT_ROAD) {
01145       RoadTypes rts = GetRoadTypes(ti->tile);
01146 
01147       if (HasBit(rts, ROADTYPE_TRAM)) {
01148         static const SpriteID tunnel_sprites[2][4] = { { 28, 78, 79, 27 }, {  5, 76, 77,  4 } };
01149 
01150         DrawGroundSprite(SPR_TRAMWAY_BASE + tunnel_sprites[rts - ROADTYPES_TRAM][tunnelbridge_direction], PAL_NONE);
01151 
01152         /* Do not draw wires if they are invisible */
01153         if (!IsInvisibilitySet(TO_CATENARY)) {
01154           catenary = true;
01155           StartSpriteCombine();
01156           AddSortableSpriteToDraw(SPR_TRAMWAY_TUNNEL_WIRES + tunnelbridge_direction, PAL_NONE, ti->x, ti->y, BB_data[10], BB_data[11], TILE_HEIGHT, ti->z, IsTransparencySet(TO_CATENARY), BB_data[8], BB_data[9], BB_Z_SEPARATOR);
01157         }
01158       }
01159     } else {
01160       const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
01161       if (rti->UsesOverlay()) {
01162         SpriteID surface = GetCustomRailSprite(rti, ti->tile, RTSG_TUNNEL);
01163         if (surface != 0) DrawGroundSprite(surface + tunnelbridge_direction, PAL_NONE);
01164       }
01165 
01166       /* PBS debugging, draw reserved tracks darker */
01167       if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasTunnelBridgeReservation(ti->tile)) {
01168         DrawGroundSprite(DiagDirToAxis(tunnelbridge_direction) == AXIS_X ? rti->base_sprites.single_x : rti->base_sprites.single_y, PALETTE_CRASH);
01169       }
01170 
01171       if (HasCatenaryDrawn(GetRailType(ti->tile))) {
01172         /* Maybe draw pylons on the entry side */
01173         DrawCatenary(ti);
01174 
01175         catenary = true;
01176         StartSpriteCombine();
01177         /* Draw wire above the ramp */
01178         DrawCatenaryOnTunnel(ti);
01179       }
01180     }
01181 
01182     if (railtype_overlay != 0 && !catenary) StartSpriteCombine();
01183 
01184     AddSortableSpriteToDraw(image + 1, PAL_NONE, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, BB_data[0], BB_data[1], TILE_HEIGHT, ti->z, false, BB_data[2], BB_data[3], BB_Z_SEPARATOR);
01185     /* Draw railtype tunnel portal overlay if defined. */
01186     if (railtype_overlay != 0) AddSortableSpriteToDraw(railtype_overlay + tunnelbridge_direction, PAL_NONE, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, BB_data[0], BB_data[1], TILE_HEIGHT, ti->z, false, BB_data[2], BB_data[3], BB_Z_SEPARATOR);
01187 
01188     if (catenary || railtype_overlay != 0) EndSpriteCombine();
01189 
01190     /* Add helper BB for sprite sorting that separates the tunnel from things beside of it. */
01191     AddSortableSpriteToDraw(SPR_EMPTY_BOUNDING_BOX, PAL_NONE, ti->x,              ti->y,              BB_data[6], BB_data[7], TILE_HEIGHT, ti->z);
01192     AddSortableSpriteToDraw(SPR_EMPTY_BOUNDING_BOX, PAL_NONE, ti->x + BB_data[4], ti->y + BB_data[5], BB_data[6], BB_data[7], TILE_HEIGHT, ti->z);
01193 
01194     DrawBridgeMiddle(ti);
01195   } else { // IsBridge(ti->tile)
01196     const PalSpriteID *psid;
01197     int base_offset;
01198     bool ice = HasTunnelBridgeSnowOrDesert(ti->tile);
01199 
01200     if (transport_type == TRANSPORT_RAIL) {
01201       base_offset = GetRailTypeInfo(GetRailType(ti->tile))->bridge_offset;
01202       assert(base_offset != 8); // This one is used for roads
01203     } else {
01204       base_offset = 8;
01205     }
01206 
01207     /* as the lower 3 bits are used for other stuff, make sure they are clear */
01208     assert( (base_offset & 0x07) == 0x00);
01209 
01210     DrawFoundation(ti, GetBridgeFoundation(ti->tileh, DiagDirToAxis(tunnelbridge_direction)));
01211 
01212     /* HACK Wizardry to convert the bridge ramp direction into a sprite offset */
01213     base_offset += (6 - tunnelbridge_direction) % 4;
01214 
01215     if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
01216 
01217     /* Table number BRIDGE_PIECE_HEAD always refers to the bridge heads for any bridge type */
01218     if (transport_type != TRANSPORT_WATER) {
01219       psid = &GetBridgeSpriteTable(GetBridgeType(ti->tile), BRIDGE_PIECE_HEAD)[base_offset];
01220     } else {
01221       psid = _aqueduct_sprites + base_offset;
01222     }
01223 
01224     if (!ice) {
01225       TileIndex next = ti->tile + TileOffsByDiagDir(tunnelbridge_direction);
01226       if (ti->tileh != SLOPE_FLAT && ti->z == 0 && HasTileWaterClass(next) && GetWaterClass(next) == WATER_CLASS_SEA) {
01227         DrawShoreTile(ti->tileh);
01228       } else {
01229         DrawClearLandTile(ti, 3);
01230       }
01231     } else {
01232       DrawGroundSprite(SPR_FLAT_SNOW_DESERT_TILE + SlopeToSpriteOffset(ti->tileh), PAL_NONE);
01233     }
01234 
01235     /* draw ramp */
01236 
01237     /* Draw Trambits and PBS Reservation as SpriteCombine */
01238     if (transport_type == TRANSPORT_ROAD || transport_type == TRANSPORT_RAIL) StartSpriteCombine();
01239 
01240     /* HACK set the height of the BB of a sloped ramp to 1 so a vehicle on
01241      * it doesn't disappear behind it
01242      */
01243     /* Bridge heads are drawn solid no matter how invisibility/transparency is set */
01244     AddSortableSpriteToDraw(psid->sprite, psid->pal, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 0 : 8, ti->z);
01245 
01246     if (transport_type == TRANSPORT_ROAD) {
01247       RoadTypes rts = GetRoadTypes(ti->tile);
01248 
01249       if (HasBit(rts, ROADTYPE_TRAM)) {
01250         uint offset = tunnelbridge_direction;
01251         int z = ti->z;
01252         if (ti->tileh != SLOPE_FLAT) {
01253           offset = (offset + 1) & 1;
01254           z += TILE_HEIGHT;
01255         } else {
01256           offset += 2;
01257         }
01258         /* DrawBridgeTramBits() calls EndSpriteCombine() and StartSpriteCombine() */
01259         DrawBridgeTramBits(ti->x, ti->y, z, offset, HasBit(rts, ROADTYPE_ROAD), true);
01260       }
01261       EndSpriteCombine();
01262     } else if (transport_type == TRANSPORT_RAIL) {
01263       const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
01264       if (rti->UsesOverlay()) {
01265         SpriteID surface = GetCustomRailSprite(rti, ti->tile, RTSG_BRIDGE);
01266         if (surface != 0) {
01267           if (HasBridgeFlatRamp(ti->tileh, DiagDirToAxis(tunnelbridge_direction))) {
01268             AddSortableSpriteToDraw(surface + ((DiagDirToAxis(tunnelbridge_direction) == AXIS_X) ? RTBO_X : RTBO_Y), PAL_NONE, ti->x, ti->y, 16, 16, 0, ti->z + 8);
01269           } else {
01270             AddSortableSpriteToDraw(surface + RTBO_SLOPE + tunnelbridge_direction, PAL_NONE, ti->x, ti->y, 16, 16, 8, ti->z);
01271           }
01272         }
01273         /* Don't fallback to non-overlay sprite -- the spec states that
01274          * if an overlay is present then the bridge surface must be
01275          * present. */
01276       }
01277 
01278       /* PBS debugging, draw reserved tracks darker */
01279       if (_game_mode != GM_MENU &&_settings_client.gui.show_track_reservation && HasTunnelBridgeReservation(ti->tile)) {
01280         if (HasBridgeFlatRamp(ti->tileh, DiagDirToAxis(tunnelbridge_direction))) {
01281           AddSortableSpriteToDraw(DiagDirToAxis(tunnelbridge_direction) == AXIS_X ? rti->base_sprites.single_x : rti->base_sprites.single_y, PALETTE_CRASH, ti->x, ti->y, 16, 16, 0, ti->z + 8);
01282         } else {
01283           AddSortableSpriteToDraw(rti->base_sprites.single_sloped + tunnelbridge_direction, PALETTE_CRASH, ti->x, ti->y, 16, 16, 8, ti->z);
01284         }
01285       }
01286 
01287       EndSpriteCombine();
01288       if (HasCatenaryDrawn(GetRailType(ti->tile))) {
01289         DrawCatenary(ti);
01290       }
01291     }
01292 
01293     DrawBridgeMiddle(ti);
01294   }
01295 }
01296 
01297 
01316 static BridgePieces CalcBridgePiece(uint north, uint south)
01317 {
01318   if (north == 1) {
01319     return BRIDGE_PIECE_NORTH;
01320   } else if (south == 1) {
01321     return BRIDGE_PIECE_SOUTH;
01322   } else if (north < south) {
01323     return north & 1 ? BRIDGE_PIECE_INNER_SOUTH : BRIDGE_PIECE_INNER_NORTH;
01324   } else if (north > south) {
01325     return south & 1 ? BRIDGE_PIECE_INNER_NORTH : BRIDGE_PIECE_INNER_SOUTH;
01326   } else {
01327     return north & 1 ? BRIDGE_PIECE_MIDDLE_EVEN : BRIDGE_PIECE_MIDDLE_ODD;
01328   }
01329 }
01330 
01335 void DrawBridgeMiddle(const TileInfo *ti)
01336 {
01337   /* Sectional view of bridge bounding boxes:
01338    *
01339    *  1           2                                1,2 = SpriteCombine of Bridge front/(back&floor) and TramCatenary
01340    *  1           2                                  3 = empty helper BB
01341    *  1     7     2                                4,5 = pillars under higher bridges
01342    *  1 6 88888 6 2                                  6 = elrail-pylons
01343    *  1 6 88888 6 2                                  7 = elrail-wire
01344    *  1 6 88888 6 2  <- TILE_HEIGHT                  8 = rail-vehicle on bridge
01345    *  3333333333333  <- BB_Z_SEPARATOR
01346    *                 <- unused
01347    *    4       5    <- BB_HEIGHT_UNDER_BRIDGE
01348    *    4       5
01349    *    4       5
01350    *
01351    */
01352 
01353   if (!IsBridgeAbove(ti->tile)) return;
01354 
01355   TileIndex rampnorth = GetNorthernBridgeEnd(ti->tile);
01356   TileIndex rampsouth = GetSouthernBridgeEnd(ti->tile);
01357   TransportType transport_type = GetTunnelBridgeTransportType(rampsouth);
01358 
01359   Axis axis = GetBridgeAxis(ti->tile);
01360   BridgePieces piece = CalcBridgePiece(
01361     GetTunnelBridgeLength(ti->tile, rampnorth) + 1,
01362     GetTunnelBridgeLength(ti->tile, rampsouth) + 1
01363   );
01364 
01365   const PalSpriteID *psid;
01366   bool drawfarpillar;
01367   if (transport_type != TRANSPORT_WATER) {
01368     BridgeType type =  GetBridgeType(rampsouth);
01369     drawfarpillar = !HasBit(GetBridgeSpec(type)->flags, 0);
01370 
01371     uint base_offset;
01372     if (transport_type == TRANSPORT_RAIL) {
01373       base_offset = GetRailTypeInfo(GetRailType(rampsouth))->bridge_offset;
01374     } else {
01375       base_offset = 8;
01376     }
01377 
01378     psid = base_offset + GetBridgeSpriteTable(type, piece);
01379   } else {
01380     drawfarpillar = true;
01381     psid = _aqueduct_sprites;
01382   }
01383 
01384   if (axis != AXIS_X) psid += 4;
01385 
01386   int x = ti->x;
01387   int y = ti->y;
01388   uint bridge_z = GetBridgePixelHeight(rampsouth);
01389   int z = bridge_z - BRIDGE_Z_START;
01390 
01391   /* Add a bounding box that separates the bridge from things below it. */
01392   AddSortableSpriteToDraw(SPR_EMPTY_BOUNDING_BOX, PAL_NONE, x, y, 16, 16, 1, bridge_z - TILE_HEIGHT + BB_Z_SEPARATOR);
01393 
01394   /* Draw Trambits as SpriteCombine */
01395   if (transport_type == TRANSPORT_ROAD || transport_type == TRANSPORT_RAIL) StartSpriteCombine();
01396 
01397   /* Draw floor and far part of bridge*/
01398   if (!IsInvisibilitySet(TO_BRIDGES)) {
01399     if (axis == AXIS_X) {
01400       AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 16, 1, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 0, BRIDGE_Z_START);
01401     } else {
01402       AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 1, 16, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 0, BRIDGE_Z_START);
01403     }
01404   }
01405 
01406   psid++;
01407 
01408   if (transport_type == TRANSPORT_ROAD) {
01409     RoadTypes rts = GetRoadTypes(rampsouth);
01410 
01411     if (HasBit(rts, ROADTYPE_TRAM)) {
01412       /* DrawBridgeTramBits() calls EndSpriteCombine() and StartSpriteCombine() */
01413       DrawBridgeTramBits(x, y, bridge_z, axis ^ 1, HasBit(rts, ROADTYPE_ROAD), false);
01414     } else {
01415       EndSpriteCombine();
01416       StartSpriteCombine();
01417     }
01418   } else if (transport_type == TRANSPORT_RAIL) {
01419     const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(rampsouth));
01420     if (rti->UsesOverlay() && !IsInvisibilitySet(TO_BRIDGES)) {
01421       SpriteID surface = GetCustomRailSprite(rti, rampsouth, RTSG_BRIDGE, TCX_ON_BRIDGE);
01422       if (surface != 0) {
01423         AddSortableSpriteToDraw(surface + axis, PAL_NONE, x, y, 16, 16, 0, bridge_z, IsTransparencySet(TO_BRIDGES));
01424       }
01425     }
01426     EndSpriteCombine();
01427 
01428     if (HasCatenaryDrawn(GetRailType(rampsouth))) {
01429       DrawCatenaryOnBridge(ti);
01430     }
01431   }
01432 
01433   /* draw roof, the component of the bridge which is logically between the vehicle and the camera */
01434   if (!IsInvisibilitySet(TO_BRIDGES)) {
01435     if (axis == AXIS_X) {
01436       y += 12;
01437       if (psid->sprite & SPRITE_MASK) AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 16, 4, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 3, BRIDGE_Z_START);
01438     } else {
01439       x += 12;
01440       if (psid->sprite & SPRITE_MASK) AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 4, 16, 0x28, z, IsTransparencySet(TO_BRIDGES), 3, 0, BRIDGE_Z_START);
01441     }
01442   }
01443 
01444   /* Draw TramFront as SpriteCombine */
01445   if (transport_type == TRANSPORT_ROAD) EndSpriteCombine();
01446 
01447   /* Do not draw anything more if bridges are invisible */
01448   if (IsInvisibilitySet(TO_BRIDGES)) return;
01449 
01450   psid++;
01451   if (ti->z + 5 == z) {
01452     /* draw poles below for small bridges */
01453     if (psid->sprite != 0) {
01454       SpriteID image = psid->sprite;
01455       SpriteID pal   = psid->pal;
01456       if (IsTransparencySet(TO_BRIDGES)) {
01457         SetBit(image, PALETTE_MODIFIER_TRANSPARENT);
01458         pal = PALETTE_TO_TRANSPARENT;
01459       }
01460 
01461       DrawGroundSpriteAt(image, pal, x - ti->x, y - ti->y, z - ti->z);
01462     }
01463   } else {
01464     /* draw pillars below for high bridges */
01465     DrawBridgePillars(psid, ti, axis, drawfarpillar, x, y, z);
01466   }
01467 }
01468 
01469 
01470 static int GetSlopePixelZ_TunnelBridge(TileIndex tile, uint x, uint y)
01471 {
01472   int z;
01473   Slope tileh = GetTilePixelSlope(tile, &z);
01474 
01475   x &= 0xF;
01476   y &= 0xF;
01477 
01478   if (IsTunnel(tile)) {
01479     uint pos = (DiagDirToAxis(GetTunnelBridgeDirection(tile)) == AXIS_X ? y : x);
01480 
01481     /* In the tunnel entrance? */
01482     if (5 <= pos && pos <= 10) return z;
01483   } else { // IsBridge(tile)
01484     DiagDirection dir = GetTunnelBridgeDirection(tile);
01485     uint pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
01486 
01487     z += ApplyPixelFoundationToSlope(GetBridgeFoundation(tileh, DiagDirToAxis(dir)), &tileh);
01488 
01489     /* On the bridge ramp? */
01490     if (5 <= pos && pos <= 10) {
01491       int delta;
01492 
01493       if (tileh != SLOPE_FLAT) return z + TILE_HEIGHT;
01494 
01495       switch (dir) {
01496         default: NOT_REACHED();
01497         case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
01498         case DIAGDIR_SE: delta = y / 2; break;
01499         case DIAGDIR_SW: delta = x / 2; break;
01500         case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
01501       }
01502       return z + 1 + delta;
01503     }
01504   }
01505 
01506   return z + GetPartialPixelZ(x, y, tileh);
01507 }
01508 
01509 static Foundation GetFoundation_TunnelBridge(TileIndex tile, Slope tileh)
01510 {
01511   return IsTunnel(tile) ? FOUNDATION_NONE : GetBridgeFoundation(tileh, DiagDirToAxis(GetTunnelBridgeDirection(tile)));
01512 }
01513 
01514 static void GetTileDesc_TunnelBridge(TileIndex tile, TileDesc *td)
01515 {
01516   TransportType tt = GetTunnelBridgeTransportType(tile);
01517 
01518   if (IsTunnel(tile)) {
01519     td->str = (tt == TRANSPORT_RAIL) ? STR_LAI_TUNNEL_DESCRIPTION_RAILROAD : STR_LAI_TUNNEL_DESCRIPTION_ROAD;
01520   } else { // IsBridge(tile)
01521     td->str = (tt == TRANSPORT_WATER) ? STR_LAI_BRIDGE_DESCRIPTION_AQUEDUCT : GetBridgeSpec(GetBridgeType(tile))->transport_name[tt];
01522   }
01523   td->owner[0] = GetTileOwner(tile);
01524 
01525   Owner road_owner = INVALID_OWNER;
01526   Owner tram_owner = INVALID_OWNER;
01527   RoadTypes rts = GetRoadTypes(tile);
01528   if (HasBit(rts, ROADTYPE_ROAD)) road_owner = GetRoadOwner(tile, ROADTYPE_ROAD);
01529   if (HasBit(rts, ROADTYPE_TRAM)) tram_owner = GetRoadOwner(tile, ROADTYPE_TRAM);
01530 
01531   /* Is there a mix of owners? */
01532   if ((tram_owner != INVALID_OWNER && tram_owner != td->owner[0]) ||
01533       (road_owner != INVALID_OWNER && road_owner != td->owner[0])) {
01534     uint i = 1;
01535     if (road_owner != INVALID_OWNER) {
01536       td->owner_type[i] = STR_LAND_AREA_INFORMATION_ROAD_OWNER;
01537       td->owner[i] = road_owner;
01538       i++;
01539     }
01540     if (tram_owner != INVALID_OWNER) {
01541       td->owner_type[i] = STR_LAND_AREA_INFORMATION_TRAM_OWNER;
01542       td->owner[i] = tram_owner;
01543     }
01544   }
01545 
01546   if (tt == TRANSPORT_RAIL) {
01547     const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(tile));
01548     td->rail_speed = rti->max_speed;
01549 
01550     if (!IsTunnel(tile)) {
01551       uint16 spd = GetBridgeSpec(GetBridgeType(tile))->speed;
01552       if (td->rail_speed == 0 || spd < td->rail_speed) {
01553         td->rail_speed = spd;
01554       }
01555     }
01556   }
01557 }
01558 
01559 
01560 static void TileLoop_TunnelBridge(TileIndex tile)
01561 {
01562   bool snow_or_desert = HasTunnelBridgeSnowOrDesert(tile);
01563   switch (_settings_game.game_creation.landscape) {
01564     case LT_ARCTIC: {
01565       /* As long as we do not have a snow density, we want to use the density
01566        * from the entry edge. For tunnels this is the lowest point for bridges the highest point.
01567        * (Independent of foundations) */
01568       int z = IsBridge(tile) ? GetTileMaxZ(tile) : GetTileZ(tile);
01569       if (snow_or_desert != (z > GetSnowLine())) {
01570         SetTunnelBridgeSnowOrDesert(tile, !snow_or_desert);
01571         MarkTileDirtyByTile(tile);
01572       }
01573       break;
01574     }
01575 
01576     case LT_TROPIC:
01577       if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
01578         SetTunnelBridgeSnowOrDesert(tile, true);
01579         MarkTileDirtyByTile(tile);
01580       }
01581       break;
01582 
01583     default:
01584       break;
01585   }
01586 }
01587 
01588 static TrackStatus GetTileTrackStatus_TunnelBridge(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
01589 {
01590   TransportType transport_type = GetTunnelBridgeTransportType(tile);
01591   if (transport_type != mode || (transport_type == TRANSPORT_ROAD && (GetRoadTypes(tile) & sub_mode) == 0)) return 0;
01592 
01593   DiagDirection dir = GetTunnelBridgeDirection(tile);
01594   if (side != INVALID_DIAGDIR && side != ReverseDiagDir(dir)) return 0;
01595   return CombineTrackStatus(TrackBitsToTrackdirBits(DiagDirToDiagTrackBits(dir)), TRACKDIR_BIT_NONE);
01596 }
01597 
01598 static void ChangeTileOwner_TunnelBridge(TileIndex tile, Owner old_owner, Owner new_owner)
01599 {
01600   TileIndex other_end = GetOtherTunnelBridgeEnd(tile);
01601   /* Set number of pieces to zero if it's the southern tile as we
01602    * don't want to update the infrastructure counts twice. */
01603   uint num_pieces = tile < other_end ? (GetTunnelBridgeLength(tile, other_end) + 2) * TUNNELBRIDGE_TRACKBIT_FACTOR : 0;
01604 
01605   for (RoadType rt = ROADTYPE_ROAD; rt < ROADTYPE_END; rt++) {
01606     /* Update all roadtypes, no matter if they are present */
01607     if (GetRoadOwner(tile, rt) == old_owner) {
01608       if (HasBit(GetRoadTypes(tile), rt)) {
01609         /* Update company infrastructure counts. A full diagonal road tile has two road bits.
01610          * No need to dirty windows here, we'll redraw the whole screen anyway. */
01611         Company::Get(old_owner)->infrastructure.road[rt] -= num_pieces * 2;
01612         if (new_owner != INVALID_OWNER) Company::Get(new_owner)->infrastructure.road[rt] += num_pieces * 2;
01613       }
01614 
01615       SetRoadOwner(tile, rt, new_owner == INVALID_OWNER ? OWNER_NONE : new_owner);
01616     }
01617   }
01618 
01619   if (!IsTileOwner(tile, old_owner)) return;
01620 
01621   /* Update company infrastructure counts for rail and water as well.
01622    * No need to dirty windows here, we'll redraw the whole screen anyway. */
01623   TransportType tt = GetTunnelBridgeTransportType(tile);
01624   Company *old = Company::Get(old_owner);
01625   if (tt == TRANSPORT_RAIL) {
01626     old->infrastructure.rail[GetRailType(tile)] -= num_pieces;
01627     if (new_owner != INVALID_OWNER) Company::Get(new_owner)->infrastructure.rail[GetRailType(tile)] += num_pieces;
01628   } else if (tt == TRANSPORT_WATER) {
01629     old->infrastructure.water -= num_pieces;
01630     if (new_owner != INVALID_OWNER) Company::Get(new_owner)->infrastructure.water += num_pieces;
01631   }
01632 
01633   if (new_owner != INVALID_OWNER) {
01634     SetTileOwner(tile, new_owner);
01635   } else {
01636     if (tt == TRANSPORT_RAIL) {
01637       /* Since all of our vehicles have been removed, it is safe to remove the rail
01638        * bridge / tunnel. */
01639       CommandCost ret = DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR);
01640       assert(ret.Succeeded());
01641     } else {
01642       /* In any other case, we can safely reassign the ownership to OWNER_NONE. */
01643       SetTileOwner(tile, OWNER_NONE);
01644     }
01645   }
01646 }
01647 
01653 static const byte TUNNEL_SOUND_FRAME = 1;
01654 
01663 extern const byte _tunnel_visibility_frame[DIAGDIR_END] = {12, 8, 8, 12};
01664 
01665 static VehicleEnterTileStatus VehicleEnter_TunnelBridge(Vehicle *v, TileIndex tile, int x, int y)
01666 {
01667   int z = GetSlopePixelZ(x, y) - v->z_pos;
01668 
01669   if (abs(z) > 2) return VETSB_CANNOT_ENTER;
01670   /* Direction into the wormhole */
01671   const DiagDirection dir = GetTunnelBridgeDirection(tile);
01672   /* Direction of the vehicle */
01673   const DiagDirection vdir = DirToDiagDir(v->direction);
01674   /* New position of the vehicle on the tile */
01675   byte pos = (DiagDirToAxis(vdir) == AXIS_X ? x : y) & TILE_UNIT_MASK;
01676   /* Number of units moved by the vehicle since entering the tile */
01677   byte frame = (vdir == DIAGDIR_NE || vdir == DIAGDIR_NW) ? TILE_SIZE - 1 - pos : pos;
01678 
01679   if (IsTunnel(tile)) {
01680     if (v->type == VEH_TRAIN) {
01681       Train *t = Train::From(v);
01682 
01683       if (t->track != TRACK_BIT_WORMHOLE && dir == vdir) {
01684         if (t->IsFrontEngine() && frame == TUNNEL_SOUND_FRAME) {
01685           if (!PlayVehicleSound(t, VSE_TUNNEL) && RailVehInfo(t->engine_type)->engclass == 0) {
01686             SndPlayVehicleFx(SND_05_TRAIN_THROUGH_TUNNEL, v);
01687           }
01688           return VETSB_CONTINUE;
01689         }
01690         if (frame == _tunnel_visibility_frame[dir]) {
01691           t->tile = tile;
01692           t->track = TRACK_BIT_WORMHOLE;
01693           t->vehstatus |= VS_HIDDEN;
01694           return VETSB_ENTERED_WORMHOLE;
01695         }
01696       }
01697 
01698       if (dir == ReverseDiagDir(vdir) && frame == TILE_SIZE - _tunnel_visibility_frame[dir] && z == 0) {
01699         /* We're at the tunnel exit ?? */
01700         t->tile = tile;
01701         t->track = DiagDirToDiagTrackBits(vdir);
01702         assert(t->track);
01703         t->vehstatus &= ~VS_HIDDEN;
01704         return VETSB_ENTERED_WORMHOLE;
01705       }
01706     } else if (v->type == VEH_ROAD) {
01707       RoadVehicle *rv = RoadVehicle::From(v);
01708 
01709       /* Enter tunnel? */
01710       if (rv->state != RVSB_WORMHOLE && dir == vdir) {
01711         if (frame == _tunnel_visibility_frame[dir]) {
01712           /* Frame should be equal to the next frame number in the RV's movement */
01713           assert(frame == rv->frame + 1);
01714           rv->tile = tile;
01715           rv->state = RVSB_WORMHOLE;
01716           rv->vehstatus |= VS_HIDDEN;
01717           return VETSB_ENTERED_WORMHOLE;
01718         } else {
01719           return VETSB_CONTINUE;
01720         }
01721       }
01722 
01723       /* We're at the tunnel exit ?? */
01724       if (dir == ReverseDiagDir(vdir) && frame == TILE_SIZE - _tunnel_visibility_frame[dir] && z == 0) {
01725         rv->tile = tile;
01726         rv->state = DiagDirToDiagTrackdir(vdir);
01727         rv->frame = frame;
01728         rv->vehstatus &= ~VS_HIDDEN;
01729         return VETSB_ENTERED_WORMHOLE;
01730       }
01731     }
01732   } else { // IsBridge(tile)
01733     if (v->type != VEH_SHIP) {
01734       /* modify speed of vehicle */
01735       uint16 spd = GetBridgeSpec(GetBridgeType(tile))->speed;
01736 
01737       if (v->type == VEH_ROAD) spd *= 2;
01738       Vehicle *first = v->First();
01739       first->cur_speed = min(first->cur_speed, spd);
01740     }
01741 
01742     if (vdir == dir) {
01743       /* Vehicle enters bridge at the last frame inside this tile. */
01744       if (frame != TILE_SIZE - 1) return VETSB_CONTINUE;
01745       switch (v->type) {
01746         case VEH_TRAIN: {
01747           Train *t = Train::From(v);
01748           t->track = TRACK_BIT_WORMHOLE;
01749           ClrBit(t->gv_flags, GVF_GOINGUP_BIT);
01750           ClrBit(t->gv_flags, GVF_GOINGDOWN_BIT);
01751           break;
01752         }
01753 
01754         case VEH_ROAD: {
01755           RoadVehicle *rv = RoadVehicle::From(v);
01756           rv->state = RVSB_WORMHOLE;
01757           /* There are no slopes inside bridges / tunnels. */
01758           ClrBit(rv->gv_flags, GVF_GOINGUP_BIT);
01759           ClrBit(rv->gv_flags, GVF_GOINGDOWN_BIT);
01760           break;
01761         }
01762 
01763         case VEH_SHIP:
01764           Ship::From(v)->state = TRACK_BIT_WORMHOLE;
01765           break;
01766 
01767         default: NOT_REACHED();
01768       }
01769       return VETSB_ENTERED_WORMHOLE;
01770     } else if (vdir == ReverseDiagDir(dir)) {
01771       v->tile = tile;
01772       switch (v->type) {
01773         case VEH_TRAIN: {
01774           Train *t = Train::From(v);
01775           if (t->track == TRACK_BIT_WORMHOLE) {
01776             t->track = DiagDirToDiagTrackBits(vdir);
01777             return VETSB_ENTERED_WORMHOLE;
01778           }
01779           break;
01780         }
01781 
01782         case VEH_ROAD: {
01783           RoadVehicle *rv = RoadVehicle::From(v);
01784           if (rv->state == RVSB_WORMHOLE) {
01785             rv->state = DiagDirToDiagTrackdir(vdir);
01786             rv->frame = 0;
01787             return VETSB_ENTERED_WORMHOLE;
01788           }
01789           break;
01790         }
01791 
01792         case VEH_SHIP: {
01793           Ship *ship = Ship::From(v);
01794           if (ship->state == TRACK_BIT_WORMHOLE) {
01795             ship->state = DiagDirToDiagTrackBits(vdir);
01796             return VETSB_ENTERED_WORMHOLE;
01797           }
01798           break;
01799         }
01800 
01801         default: NOT_REACHED();
01802       }
01803     }
01804   }
01805   return VETSB_CONTINUE;
01806 }
01807 
01808 static CommandCost TerraformTile_TunnelBridge(TileIndex tile, DoCommandFlag flags, int z_new, Slope tileh_new)
01809 {
01810   if (_settings_game.construction.build_on_slopes && AutoslopeEnabled() && IsBridge(tile) && GetTunnelBridgeTransportType(tile) != TRANSPORT_WATER) {
01811     DiagDirection direction = GetTunnelBridgeDirection(tile);
01812     Axis axis = DiagDirToAxis(direction);
01813     CommandCost res;
01814     int z_old;
01815     Slope tileh_old = GetTileSlope(tile, &z_old);
01816 
01817     /* Check if new slope is valid for bridges in general (so we can safely call GetBridgeFoundation()) */
01818     if ((direction == DIAGDIR_NW) || (direction == DIAGDIR_NE)) {
01819       CheckBridgeSlopeSouth(axis, &tileh_old, &z_old);
01820       res = CheckBridgeSlopeSouth(axis, &tileh_new, &z_new);
01821     } else {
01822       CheckBridgeSlopeNorth(axis, &tileh_old, &z_old);
01823       res = CheckBridgeSlopeNorth(axis, &tileh_new, &z_new);
01824     }
01825 
01826     /* Surface slope is valid and remains unchanged? */
01827     if (res.Succeeded() && (z_old == z_new) && (tileh_old == tileh_new)) return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
01828   }
01829 
01830   return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
01831 }
01832 
01833 extern const TileTypeProcs _tile_type_tunnelbridge_procs = {
01834   DrawTile_TunnelBridge,           // draw_tile_proc
01835   GetSlopePixelZ_TunnelBridge,     // get_slope_z_proc
01836   ClearTile_TunnelBridge,          // clear_tile_proc
01837   NULL,                            // add_accepted_cargo_proc
01838   GetTileDesc_TunnelBridge,        // get_tile_desc_proc
01839   GetTileTrackStatus_TunnelBridge, // get_tile_track_status_proc
01840   NULL,                            // click_tile_proc
01841   NULL,                            // animate_tile_proc
01842   TileLoop_TunnelBridge,           // tile_loop_proc
01843   ChangeTileOwner_TunnelBridge,    // change_tile_owner_proc
01844   NULL,                            // add_produced_cargo_proc
01845   VehicleEnter_TunnelBridge,       // vehicle_enter_tile_proc
01846   GetFoundation_TunnelBridge,      // get_foundation_proc
01847   TerraformTile_TunnelBridge,      // terraform_tile_proc
01848 };