# tunnelbridge_cmd.cpp

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    00001 /* $Id: tunnelbridge_cmd.cpp 18866 2010-01-18 22:57:21Z rubidium $ */
    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
    00015 #include "stdafx.h"
    00016 #include "rail_map.h"
    00017 #include "landscape.h"
    00018 #include "unmovable_map.h"
    00019 #include "viewport_func.h"
    00020 #include "command_func.h"
    00021 #include "town.h"
    00022 #include "variables.h"
    00023 #include "train.h"
    00024 #include "ship.h"
    00025 #include "roadveh.h"
    00026 #include "water_map.h"
    00027 #include "pathfinder/yapf/yapf_cache.h"
    00028 #include "newgrf_sound.h"
    00029 #include "autoslope.h"
    00030 #include "tunnelbridge_map.h"
    00031 #include "strings_func.h"
    00032 #include "date_func.h"
    00033 #include "functions.h"
    00034 #include "vehicle_func.h"
    00035 #include "sound_func.h"
    00036 #include "tunnelbridge.h"
    00037 #include "cheat_type.h"
    00038 #include "elrail_func.h"
    00039 #include "landscape_type.h"
    00040 #include "pbs.h"
    00041 #include "company_base.h"
    00042 #include "engine_base.h"
    00043
    00044 #include "table/sprites.h"
    00045 #include "table/strings.h"
    00046 #include "table/bridge_land.h"
    00047
    00048 BridgeSpec _bridge[MAX_BRIDGES];
    00049 TileIndex _build_tunnel_endtile;
    00050
    00052 void ResetBridges()
    00053 {
    00054   /* First, free sprite table data */
    00055   for (BridgeType i = 0; i < MAX_BRIDGES; i++) {
    00056     if (_bridge[i].sprite_table != NULL) {
    00057       for (BridgePieces j = BRIDGE_PIECE_NORTH; j < BRIDGE_PIECE_INVALID; j++) free(_bridge[i].sprite_table[j]);
    00058       free(_bridge[i].sprite_table);
    00059     }
    00060   }
    00061
    00062   /* Then, wipe out current bidges */
    00063   memset(&_bridge, 0, sizeof(_bridge));
    00064   /* And finally, reinstall default data */
    00065   memcpy(&_bridge, &_orig_bridge, sizeof(_orig_bridge));
    00066 }
    00067
    00071 int CalcBridgeLenCostFactor(int x)
    00072 {
    00073   int n;
    00074   int r;
    00075
    00076   if (x < 2) return x;
    00077   x -= 2;
    00078   for (n = 0, r = 2;; n++) {
    00079     if (x <= n) return r + x * n;
    00080     r += n * n;
    00081     x -= n;
    00082   }
    00083 }
    00084
    00085 Foundation GetBridgeFoundation(Slope tileh, Axis axis)
    00086 {
    00087   if ((tileh == SLOPE_FLAT) ||
    00088       (((tileh == SLOPE_NE) || (tileh == SLOPE_SW)) && (axis == AXIS_X)) ||
    00089       (((tileh == SLOPE_NW) || (tileh == SLOPE_SE)) && (axis == AXIS_Y))) return FOUNDATION_NONE;
    00090
    00091   return (HasSlopeHighestCorner(tileh) ? InclinedFoundation(axis) : FlatteningFoundation(tileh));
    00092 }
    00093
    00101 bool HasBridgeFlatRamp(Slope tileh, Axis axis)
    00102 {
    00103   ApplyFoundationToSlope(GetBridgeFoundation(tileh, axis), &tileh);
    00104   /* If the foundation slope is flat the bridge has a non-flat ramp and vice versa. */
    00105   return (tileh != SLOPE_FLAT);
    00106 }
    00107
    00108 static inline const PalSpriteID *GetBridgeSpriteTable(int index, BridgePieces table)
    00109 {
    00110   const BridgeSpec *bridge = GetBridgeSpec(index);
    00111   assert(table < BRIDGE_PIECE_INVALID);
    00112   if (bridge->sprite_table == NULL || bridge->sprite_table[table] == NULL) {
    00113     return _bridge_sprite_table[index][table];
    00114   } else {
    00115     return bridge->sprite_table[table];
    00116   }
    00117 }
    00118
    00119
    00128 static CommandCost CheckBridgeSlopeNorth(Axis axis, Slope *tileh, uint *z)
    00129 {
    00130   Foundation f = GetBridgeFoundation(*tileh, axis);
    00131   *z += ApplyFoundationToSlope(f, tileh);
    00132
    00133   Slope valid_inclined = (axis == AXIS_X ? SLOPE_NE : SLOPE_NW);
    00134   if ((*tileh != SLOPE_FLAT) && (*tileh != valid_inclined)) return CMD_ERROR;
    00135
    00136   if (f == FOUNDATION_NONE) return CommandCost();
    00137
    00138   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
    00139 }
    00140
    00149 static CommandCost CheckBridgeSlopeSouth(Axis axis, Slope *tileh, uint *z)
    00150 {
    00151   Foundation f = GetBridgeFoundation(*tileh, axis);
    00152   *z += ApplyFoundationToSlope(f, tileh);
    00153
    00154   Slope valid_inclined = (axis == AXIS_X ? SLOPE_SW : SLOPE_SE);
    00155   if ((*tileh != SLOPE_FLAT) && (*tileh != valid_inclined)) return CMD_ERROR;
    00156
    00157   if (f == FOUNDATION_NONE) return CommandCost();
    00158
    00159   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
    00160 }
    00161
    00162 bool CheckBridge_Stuff(BridgeType bridge_type, uint bridge_len, DoCommandFlag flags)
    00163 {
    00164   if (flags & DC_QUERY_COST) {
    00165     return bridge_len <= (_settings_game.construction.longbridges ? 100U : 16U);
    00166   }
    00167
    00168   if (bridge_type >= MAX_BRIDGES) return false;
    00169
    00170   const BridgeSpec *b = GetBridgeSpec(bridge_type);
    00171   if (b->avail_year > _cur_year) return false;
    00172
    00173   uint max = b->max_length;
    00174   if (max >= 16 && _settings_game.construction.longbridges) max = 100;
    00175
    00176   return b->min_length <= bridge_len && bridge_len <= max;
    00177 }
    00178
    00190 CommandCost CmdBuildBridge(TileIndex end_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
    00191 {
    00192   RailType railtype = INVALID_RAILTYPE;
    00193   RoadTypes roadtypes = ROADTYPES_NONE;
    00194   CommandCost cost(EXPENSES_CONSTRUCTION);
    00195   Owner owner;
    00196
    00197   /* unpack parameters */
    00198   BridgeType bridge_type = GB(p2, 0, 8);
    00199
    00200   if (p1 >= MapSize()) return CMD_ERROR;
    00201
    00202   TransportType transport_type = (TransportType)GB(p2, 15, 2);
    00203
    00204   /* type of bridge */
    00205   switch (transport_type) {
    00206     case TRANSPORT_ROAD:
    00207       roadtypes = (RoadTypes)GB(p2, 8, 2);
    00208       if (!AreValidRoadTypes(roadtypes) || !HasRoadTypesAvail(_current_company, roadtypes)) return CMD_ERROR;
    00209       break;
    00210
    00211     case TRANSPORT_RAIL:
    00212       railtype = (RailType)GB(p2, 8, 7);
    00213       if (!ValParamRailtype(railtype)) return CMD_ERROR;
    00214       break;
    00215
    00216     case TRANSPORT_WATER:
    00217       break;
    00218
    00219     default:
    00220       /* Airports don't have bridges. */
    00221       return CMD_ERROR;
    00222   }
    00223   TileIndex tile_start = p1;
    00224   TileIndex tile_end = end_tile;
    00225
    00226   if (tile_start == tile_end) {
    00227     return_cmd_error(STR_ERROR_CAN_T_START_AND_END_ON);
    00228   }
    00229
    00230   Axis direction;
    00231   if (TileX(tile_start) == TileX(tile_end)) {
    00232     direction = AXIS_Y;
    00233   } else if (TileY(tile_start) == TileY(tile_end)) {
    00234     direction = AXIS_X;
    00235   } else {
    00236     return_cmd_error(STR_ERROR_START_AND_END_MUST_BE_IN);
    00237   }
    00238
    00239   if (tile_end < tile_start) Swap(tile_start, tile_end);
    00240
    00241   uint bridge_len = GetTunnelBridgeLength(tile_start, tile_end);
    00242   if (transport_type != TRANSPORT_WATER) {
    00243     /* set and test bridge length, availability */
    00244     if (!CheckBridge_Stuff(bridge_type, bridge_len, flags)) return_cmd_error(STR_ERROR_CAN_T_BUILD_BRIDGE_HERE);
    00245   } else {
    00246     if (bridge_len > (_settings_game.construction.longbridges ? 100U : 16U)) return_cmd_error(STR_ERROR_CAN_T_BUILD_BRIDGE_HERE);
    00247   }
    00248
    00249   /* retrieve landscape height and ensure it's on land */
    00250   if (IsWaterTile(tile_start) || IsWaterTile(tile_end)) {
    00251     return_cmd_error(STR_ERROR_ENDS_OF_BRIDGE_MUST_BOTH);
    00252   }
    00253
    00254   uint z_start;
    00255   uint z_end;
    00256   Slope tileh_start = GetTileSlope(tile_start, &z_start);
    00257   Slope tileh_end = GetTileSlope(tile_end, &z_end);
    00258
    00259   CommandCost terraform_cost_north = CheckBridgeSlopeNorth(direction, &tileh_start, &z_start);
    00260   CommandCost terraform_cost_south = CheckBridgeSlopeSouth(direction, &tileh_end,   &z_end);
    00261
    00262   if (z_start != z_end) return_cmd_error(STR_ERROR_BRIDGEHEADS_NOT_SAME_HEIGHT);
    00263
    00264   if (IsBridgeTile(tile_start) && IsBridgeTile(tile_end) &&
    00265       GetOtherBridgeEnd(tile_start) == tile_end &&
    00266       GetTunnelBridgeTransportType(tile_start) == transport_type) {
    00267     /* Replace a current bridge. */
    00268
    00269     /* If this is a railway bridge, make sure the railtypes match. */
    00270     if (transport_type == TRANSPORT_RAIL && GetRailType(tile_start) != railtype) {
    00271       return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
    00272     }
    00273
    00274     /* Do not replace town bridges with lower speed bridges. */
    00275     if (!(flags & DC_QUERY_COST) && IsTileOwner(tile_start, OWNER_TOWN) &&
    00276         GetBridgeSpec(bridge_type)->speed < GetBridgeSpec(GetBridgeType(tile_start))->speed) {
    00277       Town *t = ClosestTownFromTile(tile_start, UINT_MAX);
    00278
    00279       if (t == NULL) {
    00280         return CMD_ERROR;
    00281       } else {
    00282         SetDParam(0, t->index);
    00283         return_cmd_error(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS);
    00284       }
    00285     }
    00286
    00287     /* Do not replace the bridge with the same bridge type. */
    00288     if (!(flags & DC_QUERY_COST) && bridge_type == GetBridgeType(tile_start)) {
    00289       return_cmd_error(STR_ERROR_ALREADY_BUILT);
    00290     }
    00291
    00292     /* Do not allow replacing another company's bridges. */
    00293     if (!IsTileOwner(tile_start, _current_company) && !IsTileOwner(tile_start, OWNER_TOWN)) {
    00294       return_cmd_error(STR_ERROR_AREA_IS_OWNED_BY_ANOTHER);
    00295     }
    00296
    00297     cost.AddCost((bridge_len + 1) * _price[PR_CLEAR_BRIDGE]); // The cost of clearing the current bridge.
    00298     owner = GetTileOwner(tile_start);
    00299
    00300     /* Do not remove road types when upgrading a bridge */
    00301     roadtypes |= GetRoadTypes(tile_start);
    00302   } else {
    00303     /* Build a new bridge. */
    00304
    00305     bool allow_on_slopes = (_settings_game.construction.build_on_slopes && transport_type != TRANSPORT_WATER);
    00306
    00307     /* Try and clear the start landscape */
    00308     CommandCost ret = DoCommand(tile_start, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
    00309     if (ret.Failed()) return ret;
    00310     cost = ret;
    00311
    00312     if (terraform_cost_north.Failed() || (terraform_cost_north.GetCost() != 0 && !allow_on_slopes))
    00313       return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
    00314     cost.AddCost(terraform_cost_north);
    00315
    00316     /* Try and clear the end landscape */
    00317     ret = DoCommand(tile_end, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
    00318     if (ret.Failed()) return ret;
    00319     cost.AddCost(ret);
    00320
    00321     /* false - end tile slope check */
    00322     if (terraform_cost_south.Failed() || (terraform_cost_south.GetCost() != 0 && !allow_on_slopes))
    00323       return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
    00324     cost.AddCost(terraform_cost_south);
    00325
    00326     if (transport_type == TRANSPORT_WATER && (tileh_start == SLOPE_FLAT || tileh_end == SLOPE_FLAT)) return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
    00327
    00328     const TileIndex heads[] = {tile_start, tile_end};
    00329     for (int i = 0; i < 2; i++) {
    00330       if (MayHaveBridgeAbove(heads[i])) {
    00331         if (IsBridgeAbove(heads[i])) {
    00332           TileIndex north_head = GetNorthernBridgeEnd(heads[i]);
    00333
    00334           if (direction == GetBridgeAxis(heads[i])) return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
    00335
    00336           if (z_start + TILE_HEIGHT == GetBridgeHeight(north_head)) {
    00337             return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
    00338           }
    00339         }
    00340       }
    00341     }
    00342
    00343     TileIndexDiff delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
    00344     for (TileIndex tile = tile_start + delta; tile != tile_end; tile += delta) {
    00345       if (GetTileMaxZ(tile) > z_start) return_cmd_error(STR_ERROR_BRIDGE_TOO_LOW_FOR_TERRAIN);
    00346
    00347       if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
    00348         /* Disallow crossing bridges for the time being */
    00349         return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
    00350       }
    00351
    00352       switch (GetTileType(tile)) {
    00353         case MP_WATER:
    00354           if (!IsWater(tile) && !IsCoast(tile)) goto not_valid_below;
    00355           break;
    00356
    00357         case MP_RAILWAY:
    00358           if (!IsPlainRail(tile)) goto not_valid_below;
    00359           break;
    00360
    00361         case MP_ROAD:
    00362           if (IsRoadDepot(tile)) goto not_valid_below;
    00363           break;
    00364
    00365         case MP_TUNNELBRIDGE:
    00366           if (IsTunnel(tile)) break;
    00367           if (direction == DiagDirToAxis(GetTunnelBridgeDirection(tile))) goto not_valid_below;
    00368           if (z_start < GetBridgeHeight(tile)) goto not_valid_below;
    00369           break;
    00370
    00371         case MP_UNMOVABLE:
    00372           if (!IsOwnedLand(tile)) goto not_valid_below;
    00373           break;
    00374
    00375         case MP_CLEAR:
    00376           break;
    00377
    00378         default:
    00379   not_valid_below:;
    00380           /* try and clear the middle landscape */
    00381           ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
    00382           if (ret.Failed()) return ret;
    00383           cost.AddCost(ret);
    00384           break;
    00385       }
    00386
    00387       if (flags & DC_EXEC) {
    00388         /* We do this here because when replacing a bridge with another
    00389          * type calling SetBridgeMiddle isn't needed. After all, the
    00390          * tile alread has the has_bridge_above bits set. */
    00391         SetBridgeMiddle(tile, direction);
    00392       }
    00393     }
    00394
    00395     owner = _current_company;
    00396   }
    00397
    00398   /* do the drill? */
    00399   if (flags & DC_EXEC) {
    00400     DiagDirection dir = AxisToDiagDir(direction);
    00401
    00402     switch (transport_type) {
    00403       case TRANSPORT_RAIL:
    00404         MakeRailBridgeRamp(tile_start, owner, bridge_type, dir,                 railtype);
    00405         MakeRailBridgeRamp(tile_end,   owner, bridge_type, ReverseDiagDir(dir), railtype);
    00406         break;
    00407
    00408       case TRANSPORT_ROAD:
    00409         MakeRoadBridgeRamp(tile_start, owner, bridge_type, dir,                 roadtypes);
    00410         MakeRoadBridgeRamp(tile_end,   owner, bridge_type, ReverseDiagDir(dir), roadtypes);
    00411         break;
    00412
    00413       case TRANSPORT_WATER:
    00414         MakeAqueductBridgeRamp(tile_start, owner, dir);
    00415         MakeAqueductBridgeRamp(tile_end,   owner, ReverseDiagDir(dir));
    00416         break;
    00417
    00418       default:
    00419         NOT_REACHED();
    00420     }
    00421
    00422     /* Mark all tiles dirty */
    00423     TileIndexDiff delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
    00424     for (TileIndex tile = tile_start; tile <= tile_end; tile += delta) {
    00425       MarkTileDirtyByTile(tile);
    00426     }
    00427   }
    00428
    00429   if ((flags & DC_EXEC) && transport_type == TRANSPORT_RAIL) {
    00430     Track track = AxisToTrack(direction);
    00431     AddSideToSignalBuffer(tile_start, INVALID_DIAGDIR, _current_company);
    00432     YapfNotifyTrackLayoutChange(tile_start, track);
    00433   }
    00434
    00435   /* for human player that builds the bridge he gets a selection to choose from bridges (DC_QUERY_COST)
    00436    * It's unnecessary to execute this command every time for every bridge. So it is done only
    00437    * and cost is computed in "bridge_gui.c". For AI, Towns this has to be of course calculated
    00438    */
    00439   Company *c = Company::GetIfValid(_current_company);
    00440   if (!(flags & DC_QUERY_COST) || (c != NULL && c->is_ai)) {
    00441     bridge_len += 2; // begin and end tiles/ramps
    00442
    00443     if (c != NULL) bridge_len = CalcBridgeLenCostFactor(bridge_len);
    00444
    00445     cost.AddCost((int64)bridge_len * _price[PR_BUILD_BRIDGE] * GetBridgeSpec(bridge_type)->price >> 8);
    00446
    00447     /* Aqueducts are a little more expensive. */
    00448     if (transport_type == TRANSPORT_WATER) cost.AddCost((int64)bridge_len * _price[PR_CLEAR_WATER]);
    00449   }
    00450
    00451   return cost;
    00452 }
    00453
    00454
    00463 CommandCost CmdBuildTunnel(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
    00464 {
    00465   TransportType transport_type = (TransportType)GB(p1, 9, 1);
    00466   CommandCost cost(EXPENSES_CONSTRUCTION);
    00467
    00468   _build_tunnel_endtile = 0;
    00469   if (transport_type == TRANSPORT_RAIL) {
    00470     if (!ValParamRailtype((RailType)p1)) return CMD_ERROR;
    00471   } else {
    00472     const RoadTypes rts = (RoadTypes)GB(p1, 0, 2);
    00473     if (!AreValidRoadTypes(rts) || !HasRoadTypesAvail(_current_company, rts)) return CMD_ERROR;
    00474   }
    00475
    00476   uint start_z;
    00477   uint end_z;
    00478   Slope start_tileh = GetTileSlope(start_tile, &start_z);
    00479   DiagDirection direction = GetInclinedSlopeDirection(start_tileh);
    00480   if (direction == INVALID_DIAGDIR) return_cmd_error(STR_ERROR_SITE_UNSUITABLE_FOR_TUNNEL);
    00481
    00482   if (IsWaterTile(start_tile)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
    00483
    00484   CommandCost ret = DoCommand(start_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
    00485   if (ret.Failed()) return ret;
    00486
    00487   /* XXX - do NOT change 'ret' in the loop, as it is used as the price
    00488    * for the clearing of the entrance of the tunnel. Assigning it to
    00489    * cost before the loop will yield different costs depending on start-
    00490    * position, because of increased-cost-by-length: 'cost += cost >> 3' */
    00491
    00492   TileIndexDiff delta = TileOffsByDiagDir(direction);
    00493   DiagDirection tunnel_in_way_dir;
    00494   if (DiagDirToAxis(direction) == AXIS_Y) {
    00495     tunnel_in_way_dir = (TileX(start_tile) < (MapMaxX() / 2)) ? DIAGDIR_SW : DIAGDIR_NE;
    00496   } else {
    00497     tunnel_in_way_dir = (TileY(start_tile) < (MapMaxX() / 2)) ? DIAGDIR_SE : DIAGDIR_NW;
    00498   }
    00499
    00500   TileIndex end_tile = start_tile;
    00501
    00502   /* Tile shift coeficient. Will decrease for very long tunnels to avoid exponential growth of price*/
    00503   int tiles_coef = 3;
    00504   /* Number of tiles from start of tunnel */
    00505   int tiles = 0;
    00506   /* Number of tiles at which the cost increase coefficient per tile is halved */
    00507   int tiles_bump = 25;
    00508
    00509   Slope end_tileh;
    00510   for (;;) {
    00511     end_tile += delta;
    00512     if (!IsValidTile(end_tile)) return_cmd_error(STR_ERROR_TUNNEL_THROUGH_MAP_BORDER);
    00513     end_tileh = GetTileSlope(end_tile, &end_z);
    00514
    00515     if (start_z == end_z) break;
    00516
    00517     if (!_cheats.crossing_tunnels.value && IsTunnelInWayDir(end_tile, start_z, tunnel_in_way_dir)) {
    00518       return_cmd_error(STR_ERROR_ANOTHER_TUNNEL_IN_THE_WAY);
    00519     }
    00520
    00521     tiles++;
    00522     if (tiles == tiles_bump) {
    00523       tiles_coef++;
    00524       tiles_bump *= 2;
    00525     }
    00526
    00527     cost.AddCost(_price[PR_BUILD_TUNNEL]);
    00528     cost.AddCost(cost.GetCost() >> tiles_coef); // add a multiplier for longer tunnels
    00529   }
    00530
    00531   /* Add the cost of the entrance */
    00532   cost.AddCost(_price[PR_BUILD_TUNNEL]);
    00533   cost.AddCost(ret);
    00534
    00535   /* if the command fails from here on we want the end tile to be highlighted */
    00536   _build_tunnel_endtile = end_tile;
    00537
    00538   if (IsWaterTile(end_tile)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
    00539
    00540   /* slope of end tile must be complementary to the slope of the start tile */
    00541   if (end_tileh != ComplementSlope(start_tileh)) {
    00542     /* Check if there is a structure on the terraformed tile. Do not add the cost, that will be done by the terraforming
    00543      * Note: Currently the town rating is also affected by this clearing-test. So effectivly the player is punished twice for clearing
    00544      *       the tree on end_tile.
    00545      */
    00546     ret = DoCommand(end_tile, 0, 0, DC_AUTO, CMD_LANDSCAPE_CLEAR);
    00547     if (ret.Failed()) return_cmd_error(STR_ERROR_UNABLE_TO_EXCAVATE_LAND);
    00548
    00549     ret = DoCommand(end_tile, end_tileh & start_tileh, 0, flags, CMD_TERRAFORM_LAND);
    00550     if (ret.Failed()) return_cmd_error(STR_ERROR_UNABLE_TO_EXCAVATE_LAND);
    00551   } else {
    00552     ret = DoCommand(end_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
    00553     if (ret.Failed()) return ret;
    00554   }
    00555   cost.AddCost(_price[PR_BUILD_TUNNEL]);
    00556   cost.AddCost(ret);
    00557
    00558   if (flags & DC_EXEC) {
    00559     if (transport_type == TRANSPORT_RAIL) {
    00560       MakeRailTunnel(start_tile, _current_company, direction,                 (RailType)GB(p1, 0, 4));
    00561       MakeRailTunnel(end_tile,   _current_company, ReverseDiagDir(direction), (RailType)GB(p1, 0, 4));
    00562       AddSideToSignalBuffer(start_tile, INVALID_DIAGDIR, _current_company);
    00563       YapfNotifyTrackLayoutChange(start_tile, DiagDirToDiagTrack(direction));
    00564     } else {
    00565       MakeRoadTunnel(start_tile, _current_company, direction,                 (RoadTypes)GB(p1, 0, 2));
    00566       MakeRoadTunnel(end_tile,   _current_company, ReverseDiagDir(direction), (RoadTypes)GB(p1, 0, 2));
    00567     }
    00568   }
    00569
    00570   return cost;
    00571 }
    00572
    00573
    00574 static inline bool CheckAllowRemoveTunnelBridge(TileIndex tile)
    00575 {
    00576   /* Floods can remove anything as well as the scenario editor */
    00577   if (_current_company == OWNER_WATER || _game_mode == GM_EDITOR) return true;
    00578
    00579   switch (GetTunnelBridgeTransportType(tile)) {
    00580     case TRANSPORT_ROAD: {
    00581       RoadTypes rts = GetRoadTypes(tile);
    00582       Owner road_owner = _current_company;
    00583       Owner tram_owner = _current_company;
    00584
    00585       if (HasBit(rts, ROADTYPE_ROAD)) road_owner = GetRoadOwner(tile, ROADTYPE_ROAD);
    00586       if (HasBit(rts, ROADTYPE_TRAM)) tram_owner = GetRoadOwner(tile, ROADTYPE_TRAM);
    00587
    00588       /* We can remove unowned road and if the town allows it */
    00589       if (road_owner == OWNER_TOWN && !(_settings_game.construction.extra_dynamite || _cheats.magic_bulldozer.value)) return CheckTileOwnership(tile);
    00590       if (road_owner == OWNER_NONE || road_owner == OWNER_TOWN) road_owner = _current_company;
    00591       if (tram_owner == OWNER_NONE) tram_owner = _current_company;
    00592
    00593       return CheckOwnership(road_owner, tile) && CheckOwnership(tram_owner, tile);
    00594     }
    00595
    00596     case TRANSPORT_RAIL:
    00597     case TRANSPORT_WATER:
    00598       return CheckOwnership(GetTileOwner(tile));
    00599
    00600     default: NOT_REACHED();
    00601   }
    00602 }
    00603
    00604 static CommandCost DoClearTunnel(TileIndex tile, DoCommandFlag flags)
    00605 {
    00606   Town *t = NULL;
    00607   TileIndex endtile;
    00608
    00609   if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
    00610
    00611   endtile = GetOtherTunnelEnd(tile);
    00612
    00613   if (HasVehicleOnTunnelBridge(tile, endtile)) return CMD_ERROR;
    00614
    00615   _build_tunnel_endtile = endtile;
    00616
    00617   if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
    00618     t = ClosestTownFromTile(tile, UINT_MAX); // town penalty rating
    00619
    00620     /* Check if you are allowed to remove the tunnel owned by a town
    00621      * Removal depends on difficulty settings */
    00622     if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
    00623       SetDParam(0, t->index);
    00624       return_cmd_error(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS);
    00625     }
    00626   }
    00627
    00628   /* checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
    00629    * you have a "Poor" (0) town rating */
    00630   if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
    00631     ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM, flags);
    00632   }
    00633
    00634   if (flags & DC_EXEC) {
    00635     if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {
    00636       /* We first need to request values before calling DoClearSquare */
    00637       DiagDirection dir = GetTunnelBridgeDirection(tile);
    00638       Track track = DiagDirToDiagTrack(dir);
    00639       Owner owner = GetTileOwner(tile);
    00640
    00641       Train *v = NULL;
    00642       if (HasTunnelBridgeReservation(tile)) {
    00643         v = GetTrainForReservation(tile, track);
    00644         if (v != NULL) FreeTrainTrackReservation(v);
    00645       }
    00646
    00647       DoClearSquare(tile);
    00648       DoClearSquare(endtile);
    00649
    00650       /* cannot use INVALID_DIAGDIR for signal update because the tunnel doesn't exist anymore */
    00651       AddSideToSignalBuffer(tile,    ReverseDiagDir(dir), owner);
    00652       AddSideToSignalBuffer(endtile, dir,                 owner);
    00653
    00654       YapfNotifyTrackLayoutChange(tile,    track);
    00655       YapfNotifyTrackLayoutChange(endtile, track);
    00656
    00657       if (v != NULL) TryPathReserve(v);
    00658     } else {
    00659       DoClearSquare(tile);
    00660       DoClearSquare(endtile);
    00661     }
    00662   }
    00663   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_TUNNEL] * (GetTunnelBridgeLength(tile, endtile) + 2));
    00664 }
    00665
    00666
    00667 static CommandCost DoClearBridge(TileIndex tile, DoCommandFlag flags)
    00668 {
    00669   DiagDirection direction;
    00670   TileIndexDiff delta;
    00671   TileIndex endtile;
    00672   Town *t = NULL;
    00673
    00674   if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
    00675
    00676   endtile = GetOtherBridgeEnd(tile);
    00677
    00678   if (HasVehicleOnTunnelBridge(tile, endtile)) return CMD_ERROR;
    00679
    00680   direction = GetTunnelBridgeDirection(tile);
    00681   delta = TileOffsByDiagDir(direction);
    00682
    00683   if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
    00684     t = ClosestTownFromTile(tile, UINT_MAX); // town penalty rating
    00685
    00686     /* Check if you are allowed to remove the bridge owned by a town
    00687      * Removal depends on difficulty settings */
    00688     if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
    00689       SetDParam(0, t->index);
    00690       return_cmd_error(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS);
    00691     }
    00692   }
    00693
    00694   /* checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
    00695    * you have a "Poor" (0) town rating */
    00696   if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
    00697     ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM, flags);
    00698   }
    00699
    00700   if (flags & DC_EXEC) {
    00701     /* read this value before actual removal of bridge */
    00702     bool rail = GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL;
    00703     Owner owner = GetTileOwner(tile);
    00704     uint height = GetBridgeHeight(tile);
    00705     Train *v = NULL;
    00706
    00707     if (rail && HasTunnelBridgeReservation(tile)) {
    00708       v = GetTrainForReservation(tile, DiagDirToDiagTrack(direction));
    00709       if (v != NULL) FreeTrainTrackReservation(v);
    00710     }
    00711
    00712     DoClearSquare(tile);
    00713     DoClearSquare(endtile);
    00714     for (TileIndex c = tile + delta; c != endtile; c += delta) {
    00715       /* do not let trees appear from 'nowhere' after removing bridge */
    00716       if (IsNormalRoadTile(c) && GetRoadside(c) == ROADSIDE_TREES) {
    00717         uint minz = GetTileMaxZ(c) + 3 * TILE_HEIGHT;
    00718         if (height < minz) SetRoadside(c, ROADSIDE_PAVED);
    00719       }
    00720       ClearBridgeMiddle(c);
    00721       MarkTileDirtyByTile(c);
    00722     }
    00723
    00724     if (rail) {
    00725       /* cannot use INVALID_DIAGDIR for signal update because the bridge doesn't exist anymore */
    00726       AddSideToSignalBuffer(tile,    ReverseDiagDir(direction), owner);
    00727       AddSideToSignalBuffer(endtile, direction,                 owner);
    00728
    00729       Track track = DiagDirToDiagTrack(direction);
    00730       YapfNotifyTrackLayoutChange(tile,    track);
    00731       YapfNotifyTrackLayoutChange(endtile, track);
    00732
    00733       if (v != NULL) TryPathReserve(v, true);
    00734     }
    00735   }
    00736
    00737   return CommandCost(EXPENSES_CONSTRUCTION, (GetTunnelBridgeLength(tile, endtile) + 2) * _price[PR_CLEAR_BRIDGE]);
    00738 }
    00739
    00740 static CommandCost ClearTile_TunnelBridge(TileIndex tile, DoCommandFlag flags)
    00741 {
    00742   if (IsTunnel(tile)) {
    00743     if (flags & DC_AUTO) return_cmd_error(STR_ERROR_MUST_DEMOLISH_TUNNEL_FIRST);
    00744     return DoClearTunnel(tile, flags);
    00745   } else { // IsBridge(tile)
    00746     if (flags & DC_AUTO) return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
    00747     return DoClearBridge(tile, flags);
    00748   }
    00749
    00750   return CMD_ERROR;
    00751 }
    00752
    00764 static void DrawBridgePillars(const PalSpriteID *psid, const TileInfo *ti, Axis axis, bool drawfarpillar, int x, int y, int z_bridge)
    00765 {
    00766   /* Do not draw bridge pillars if they are invisible */
    00767   if (IsInvisibilitySet(TO_BRIDGES)) return;
    00768
    00769   SpriteID image = psid->sprite;
    00770
    00771   if (image != 0) {
    00772     /* "side" specifies the side the pillars stand on.
    00773      * The length of the pillars is then set to the height of the bridge over the corners of this edge.
    00774      *
    00775      *                axis==AXIS_X  axis==AXIS_Y
    00776      *   side==false      SW            NW
    00777      *   side==true       NE            SE
    00778      *
    00779      * I have no clue, why this was done this way.
    00780      */
    00781     bool side = HasBit(image, 0);
    00782
    00783     /* "dir" means the edge the pillars stand on */
    00784     DiagDirection dir = AxisToDiagDir(axis);
    00785     if (side != (axis == AXIS_Y)) dir = ReverseDiagDir(dir);
    00786
    00787     /* Determine ground height under pillars */
    00788     int front_height = ti->z;
    00789     int back_height = ti->z;
    00790     GetSlopeZOnEdge(ti->tileh, dir, &front_height, &back_height);
    00791
    00792     /* x and y size of bounding-box of pillars */
    00793     int w = (axis == AXIS_X ? 16 : 2);
    00794     int h = (axis == AXIS_X ? 2 : 16);
    00795     /* sprite position of back facing pillar */
    00796     int x_back = x - (axis == AXIS_X ? 0 : 9);
    00797     int y_back = y - (axis == AXIS_X ? 9 : 0);
    00798
    00799     for (int cur_z = z_bridge; cur_z >= front_height || cur_z >= back_height; cur_z -= TILE_HEIGHT) {
    00800       /* Draw front facing pillar */
    00801       if (cur_z >= front_height) {
    00802         AddSortableSpriteToDraw(image, psid->pal, x, y, w, h, BB_HEIGHT_UNDER_BRIDGE - 5, cur_z, IsTransparencySet(TO_BRIDGES), 0, 0, -5);
    00803       }
    00804
    00805       /* Draw back facing pillar, but not the highest part directly under the bridge-floor */
    00806       if (drawfarpillar && cur_z >= back_height && cur_z < z_bridge - TILE_HEIGHT) {
    00807         AddSortableSpriteToDraw(image, psid->pal, x_back, y_back, w, h, BB_HEIGHT_UNDER_BRIDGE - 5, cur_z, IsTransparencySet(TO_BRIDGES), 0, 0, -5);
    00808       }
    00809     }
    00810   }
    00811 }
    00812
    00822 static void DrawBridgeTramBits(int x, int y, byte z, int offset, bool overlay, bool head)
    00823 {
    00824   static const SpriteID tram_offsets[2][6] = { { 107, 108, 109, 110, 111, 112 }, { 4, 5, 15, 16, 17, 18 } };
    00825   static const SpriteID back_offsets[6]    =   {  95,  96,  99, 102, 100, 101 };
    00826   static const SpriteID front_offsets[6]   =   {  97,  98, 103, 106, 104, 105 };
    00827
    00828   static const uint size_x[6] = {  1, 16, 16,  1, 16,  1 };
    00829   static const uint size_y[6] = { 16,  1,  1, 16,  1, 16 };
    00830   static const uint front_bb_offset_x[6] = { 15,  0,  0, 15,  0, 15 };
    00831   static const uint front_bb_offset_y[6] = {  0, 15, 15,  0, 15,  0 };
    00832
    00833   /* The sprites under the vehicles are drawn as SpriteCombine. StartSpriteCombine() has already been called
    00834    * The bounding boxes here are the same as for bridge front/roof */
    00835   if (head || !IsInvisibilitySet(TO_BRIDGES)) {
    00836     AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + tram_offsets[overlay][offset], PAL_NONE,
    00837       x, y, size_x[offset], size_y[offset], 0x28, z,
    00838       !head && IsTransparencySet(TO_BRIDGES));
    00839   }
    00840
    00841   /* Do not draw catenary if it is set invisible */
    00842   if (!IsInvisibilitySet(TO_CATENARY)) {
    00843     AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + back_offsets[offset], PAL_NONE,
    00844       x, y, size_x[offset], size_y[offset], 0x28, z,
    00845       IsTransparencySet(TO_CATENARY));
    00846   }
    00847
    00848   /* Start a new SpriteCombine for the front part */
    00849   EndSpriteCombine();
    00850   StartSpriteCombine();
    00851
    00852   /* For sloped sprites the bounding box needs to be higher, as the pylons stop on a higher point */
    00853   if (!IsInvisibilitySet(TO_CATENARY)) {
    00854     AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + front_offsets[offset], PAL_NONE,
    00855       x, y, size_x[offset] + front_bb_offset_x[offset], size_y[offset] + front_bb_offset_y[offset], 0x28, z,
    00856       IsTransparencySet(TO_CATENARY), front_bb_offset_x[offset], front_bb_offset_y[offset]);
    00857   }
    00858 }
    00859
    00873 static void DrawTile_TunnelBridge(TileInfo *ti)
    00874 {
    00875   SpriteID image;
    00876   TransportType transport_type = GetTunnelBridgeTransportType(ti->tile);
    00877   DiagDirection tunnelbridge_direction = GetTunnelBridgeDirection(ti->tile);
    00878
    00879   if (IsTunnel(ti->tile)) {
    00880     /* Front view of tunnel bounding boxes:
    00881      *
    00882      *   122223  <- BB_Z_SEPARATOR
    00883      *   1    3
    00884      *   1    3                1,3 = empty helper BB
    00885      *   1    3                  2 = SpriteCombine of tunnel-roof and catenary (tram & elrail)
    00886      *
    00887      */
    00888
    00889     static const int _tunnel_BB[4][12] = {
    00890       /*  tunnnel-roof  |  Z-separator  | tram-catenary
    00891        * w  h  bb_x bb_y| x   y   w   h |bb_x bb_y w h */
    00892       {  1,  0, -15, -14,  0, 15, 16,  1, 0, 1, 16, 15 }, // NE
    00893       {  0,  1, -14, -15, 15,  0,  1, 16, 1, 0, 15, 16 }, // SE
    00894       {  1,  0, -15, -14,  0, 15, 16,  1, 0, 1, 16, 15 }, // SW
    00895       {  0,  1, -14, -15, 15,  0,  1, 16, 1, 0, 15, 16 }, // NW
    00896     };
    00897     const int *BB_data = _tunnel_BB[tunnelbridge_direction];
    00898
    00899     bool catenary = false;
    00900
    00901     if (transport_type == TRANSPORT_RAIL) {
    00902       image = GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.tunnel;
    00903     } else {
    00904       image = SPR_TUNNEL_ENTRY_REAR_ROAD;
    00905     }
    00906
    00907     if (HasTunnelBridgeSnowOrDesert(ti->tile)) image += 32;
    00908
    00909     image += tunnelbridge_direction * 2;
    00910     DrawGroundSprite(image, PAL_NONE);
    00911
    00912     /* PBS debugging, draw reserved tracks darker */
    00913     if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && (transport_type == TRANSPORT_RAIL && HasTunnelBridgeReservation(ti->tile))) {
    00914       const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
    00915       DrawGroundSprite(DiagDirToAxis(tunnelbridge_direction) == AXIS_X ? rti->base_sprites.single_x : rti->base_sprites.single_y, PALETTE_CRASH);
    00916     }
    00917
    00918     if (transport_type == TRANSPORT_ROAD) {
    00919       RoadTypes rts = GetRoadTypes(ti->tile);
    00920
    00921       if (HasBit(rts, ROADTYPE_TRAM)) {
    00922         static const SpriteID tunnel_sprites[2][4] = { { 28, 78, 79, 27 }, {  5, 76, 77,  4 } };
    00923
    00924         DrawGroundSprite(SPR_TRAMWAY_BASE + tunnel_sprites[rts - ROADTYPES_TRAM][tunnelbridge_direction], PAL_NONE);
    00925
    00926         /* Do not draw wires if they are invisible */
    00927         if (!IsInvisibilitySet(TO_CATENARY)) {
    00928           catenary = true;
    00929           StartSpriteCombine();
    00930           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);
    00931         }
    00932       }
    00933     } else if (HasCatenaryDrawn(GetRailType(ti->tile))) {
    00934       /* Maybe draw pylons on the entry side */
    00935       DrawCatenary(ti);
    00936
    00937       catenary = true;
    00938       StartSpriteCombine();
    00939       /* Draw wire above the ramp */
    00940       DrawCatenaryOnTunnel(ti);
    00941     }
    00942
    00943     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);
    00944
    00945     if (catenary) EndSpriteCombine();
    00946
    00947     /* Add helper BB for sprite sorting, that separate the tunnel from things beside of it */
    00948     AddSortableSpriteToDraw(SPR_EMPTY_BOUNDING_BOX, PAL_NONE, ti->x,              ti->y,              BB_data[6], BB_data[7], TILE_HEIGHT, ti->z);
    00949     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);
    00950
    00951     DrawBridgeMiddle(ti);
    00952   } else { // IsBridge(ti->tile)
    00953     const PalSpriteID *psid;
    00954     int base_offset;
    00955     bool ice = HasTunnelBridgeSnowOrDesert(ti->tile);
    00956
    00957     if (transport_type == TRANSPORT_RAIL) {
    00958       base_offset = GetRailTypeInfo(GetRailType(ti->tile))->bridge_offset;
    00959       assert(base_offset != 8); // This one is used for roads
    00960     } else {
    00961       base_offset = 8;
    00962     }
    00963
    00964     /* as the lower 3 bits are used for other stuff, make sure they are clear */
    00965     assert( (base_offset & 0x07) == 0x00);
    00966
    00967     DrawFoundation(ti, GetBridgeFoundation(ti->tileh, DiagDirToAxis(tunnelbridge_direction)));
    00968
    00969     /* HACK Wizardry to convert the bridge ramp direction into a sprite offset */
    00970     base_offset += (6 - tunnelbridge_direction) % 4;
    00971
    00972     if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
    00973
    00974     /* Table number BRIDGE_PIECE_HEAD always refers to the bridge heads for any bridge type */
    00975     if (transport_type != TRANSPORT_WATER) {
    00976       psid = &GetBridgeSpriteTable(GetBridgeType(ti->tile), BRIDGE_PIECE_HEAD)[base_offset];
    00977     } else {
    00978       psid = _aqueduct_sprites + base_offset;
    00979     }
    00980
    00981     if (!ice) {
    00982       DrawClearLandTile(ti, 3);
    00983     } else {
    00984       DrawGroundSprite(SPR_FLAT_SNOW_DESERT_TILE + _tileh_to_sprite[ti->tileh], PAL_NONE);
    00985     }
    00986
    00987     /* draw ramp */
    00988
    00989     /* Draw Trambits and PBS Reservation as SpriteCombine */
    00990     if (transport_type == TRANSPORT_ROAD || transport_type == TRANSPORT_RAIL) StartSpriteCombine();
    00991
    00992     /* HACK set the height of the BB of a sloped ramp to 1 so a vehicle on
    00993      * it doesn't disappear behind it
    00994      */
    00995     /* Bridge heads are drawn solid no matter how invisibility/transparency is set */
    00996     AddSortableSpriteToDraw(psid->sprite, psid->pal, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 0 : 8, ti->z);
    00997
    00998     if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && transport_type == TRANSPORT_RAIL && HasTunnelBridgeReservation(ti->tile)) {
    00999       const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
    01000       if (HasBridgeFlatRamp(ti->tileh, DiagDirToAxis(tunnelbridge_direction))) {
    01001         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);
    01002       } else {
    01003         AddSortableSpriteToDraw(rti->base_sprites.single_sloped + tunnelbridge_direction, PALETTE_CRASH, ti->x, ti->y, 16, 16, 8, ti->z);
    01004       }
    01005     }
    01006
    01007     if (transport_type == TRANSPORT_ROAD) {
    01008       RoadTypes rts = GetRoadTypes(ti->tile);
    01009
    01010       if (HasBit(rts, ROADTYPE_TRAM)) {
    01011         uint offset = tunnelbridge_direction;
    01012         uint z = ti->z;
    01013         if (ti->tileh != SLOPE_FLAT) {
    01014           offset = (offset + 1) & 1;
    01015           z += TILE_HEIGHT;
    01016         } else {
    01017           offset += 2;
    01018         }
    01019         /* DrawBridgeTramBits() calls EndSpriteCombine() and StartSpriteCombine() */
    01020         DrawBridgeTramBits(ti->x, ti->y, z, offset, HasBit(rts, ROADTYPE_ROAD), true);
    01021       }
    01022       EndSpriteCombine();
    01023     } else if (transport_type == TRANSPORT_RAIL) {
    01024       EndSpriteCombine();
    01025       if (HasCatenaryDrawn(GetRailType(ti->tile))) {
    01026         DrawCatenary(ti);
    01027       }
    01028     }
    01029
    01030     DrawBridgeMiddle(ti);
    01031   }
    01032 }
    01033
    01034
    01052 static BridgePieces CalcBridgePiece(uint north, uint south)
    01053 {
    01054   if (north == 1) {
    01055     return BRIDGE_PIECE_NORTH;
    01056   } else if (south == 1) {
    01057     return BRIDGE_PIECE_SOUTH;
    01058   } else if (north < south) {
    01059     return north & 1 ? BRIDGE_PIECE_INNER_SOUTH : BRIDGE_PIECE_INNER_NORTH;
    01060   } else if (north > south) {
    01061     return south & 1 ? BRIDGE_PIECE_INNER_NORTH : BRIDGE_PIECE_INNER_SOUTH;
    01062   } else {
    01063     return north & 1 ? BRIDGE_PIECE_MIDDLE_EVEN : BRIDGE_PIECE_MIDDLE_ODD;
    01064   }
    01065 }
    01066
    01067
    01068 void DrawBridgeMiddle(const TileInfo *ti)
    01069 {
    01070   /* Sectional view of bridge bounding boxes:
    01071    *
    01072    *  1           2                                1,2 = SpriteCombine of Bridge front/(back&floor) and TramCatenary
    01073    *  1           2                                  3 = empty helper BB
    01074    *  1     7     2                                4,5 = pillars under higher bridges
    01075    *  1 6 88888 6 2                                  6 = elrail-pylons
    01076    *  1 6 88888 6 2                                  7 = elrail-wire
    01077    *  1 6 88888 6 2  <- TILE_HEIGHT                  8 = rail-vehicle on bridge
    01078    *  3333333333333  <- BB_Z_SEPARATOR
    01079    *                 <- unused
    01080    *    4       5    <- BB_HEIGHT_UNDER_BRIDGE
    01081    *    4       5
    01082    *    4       5
    01083    *
    01084    */
    01085
    01086   /* Z position of the bridge sprites relative to bridge height (downwards) */
    01087   static const int BRIDGE_Z_START = 3;
    01088
    01089   if (!IsBridgeAbove(ti->tile)) return;
    01090
    01091   TileIndex rampnorth = GetNorthernBridgeEnd(ti->tile);
    01092   TileIndex rampsouth = GetSouthernBridgeEnd(ti->tile);
    01093   TransportType transport_type = GetTunnelBridgeTransportType(rampsouth);
    01094
    01095   Axis axis = GetBridgeAxis(ti->tile);
    01096   BridgePieces piece = CalcBridgePiece(
    01097     GetTunnelBridgeLength(ti->tile, rampnorth) + 1,
    01098     GetTunnelBridgeLength(ti->tile, rampsouth) + 1
    01099   );
    01100
    01101   const PalSpriteID *psid;
    01102   bool drawfarpillar;
    01103   if (transport_type != TRANSPORT_WATER) {
    01104     BridgeType type =  GetBridgeType(rampsouth);
    01105     drawfarpillar = !HasBit(GetBridgeSpec(type)->flags, 0);
    01106
    01107     uint base_offset;
    01108     if (transport_type == TRANSPORT_RAIL) {
    01109       base_offset = GetRailTypeInfo(GetRailType(rampsouth))->bridge_offset;
    01110     } else {
    01111       base_offset = 8;
    01112     }
    01113
    01114     psid = base_offset + GetBridgeSpriteTable(type, piece);
    01115   } else {
    01116     drawfarpillar = true;
    01117     psid = _aqueduct_sprites;
    01118   }
    01119
    01120   if (axis != AXIS_X) psid += 4;
    01121
    01122   int x = ti->x;
    01123   int y = ti->y;
    01124   uint bridge_z = GetBridgeHeight(rampsouth);
    01125   uint z = bridge_z - BRIDGE_Z_START;
    01126
    01127   /* Add a bounding box, that separates the bridge from things below it. */
    01128   AddSortableSpriteToDraw(SPR_EMPTY_BOUNDING_BOX, PAL_NONE, x, y, 16, 16, 1, bridge_z - TILE_HEIGHT + BB_Z_SEPARATOR);
    01129
    01130   /* Draw Trambits as SpriteCombine */
    01131   if (transport_type == TRANSPORT_ROAD) StartSpriteCombine();
    01132
    01133   /* Draw floor and far part of bridge*/
    01134   if (!IsInvisibilitySet(TO_BRIDGES)) {
    01135     if (axis == AXIS_X) {
    01136       AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 16, 1, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 0, BRIDGE_Z_START);
    01137     } else {
    01138       AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 1, 16, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 0, BRIDGE_Z_START);
    01139     }
    01140   }
    01141
    01142   psid++;
    01143
    01144   if (transport_type == TRANSPORT_ROAD) {
    01145     RoadTypes rts = GetRoadTypes(rampsouth);
    01146
    01147     if (HasBit(rts, ROADTYPE_TRAM)) {
    01148       /* DrawBridgeTramBits() calls EndSpriteCombine() and StartSpriteCombine() */
    01149       DrawBridgeTramBits(x, y, bridge_z, axis ^ 1, HasBit(rts, ROADTYPE_ROAD), false);
    01150     } else {
    01151       EndSpriteCombine();
    01152       StartSpriteCombine();
    01153     }
    01154   } else if (transport_type == TRANSPORT_RAIL) {
    01155     if (HasCatenaryDrawn(GetRailType(rampsouth))) {
    01156       DrawCatenaryOnBridge(ti);
    01157     }
    01158   }
    01159
    01160   /* draw roof, the component of the bridge which is logically between the vehicle and the camera */
    01161   if (!IsInvisibilitySet(TO_BRIDGES)) {
    01162     if (axis == AXIS_X) {
    01163       y += 12;
    01164       if (psid->sprite & SPRITE_MASK) AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 16, 4, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 3, BRIDGE_Z_START);
    01165     } else {
    01166       x += 12;
    01167       if (psid->sprite & SPRITE_MASK) AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 4, 16, 0x28, z, IsTransparencySet(TO_BRIDGES), 3, 0, BRIDGE_Z_START);
    01168     }
    01169   }
    01170
    01171   /* Draw TramFront as SpriteCombine */
    01172   if (transport_type == TRANSPORT_ROAD) EndSpriteCombine();
    01173
    01174   /* Do not draw anything more if bridges are invisible */
    01175   if (IsInvisibilitySet(TO_BRIDGES)) return;
    01176
    01177   psid++;
    01178   if (ti->z + 5 == z) {
    01179     /* draw poles below for small bridges */
    01180     if (psid->sprite != 0) {
    01181       SpriteID image = psid->sprite;
    01182       SpriteID pal   = psid->pal;
    01183       if (IsTransparencySet(TO_BRIDGES)) {
    01184         SetBit(image, PALETTE_MODIFIER_TRANSPARENT);
    01185         pal = PALETTE_TO_TRANSPARENT;
    01186       }
    01187
    01188       DrawGroundSpriteAt(image, pal, x - ti->x, y - ti->y, z - ti->z);
    01189     }
    01190   } else if (_settings_client.gui.bridge_pillars) {
    01191     /* draw pillars below for high bridges */
    01192     DrawBridgePillars(psid, ti, axis, drawfarpillar, x, y, z);
    01193   }
    01194 }
    01195
    01196
    01197 static uint GetSlopeZ_TunnelBridge(TileIndex tile, uint x, uint y)
    01198 {
    01199   uint z;
    01200   Slope tileh = GetTileSlope(tile, &z);
    01201
    01202   x &= 0xF;
    01203   y &= 0xF;
    01204
    01205   if (IsTunnel(tile)) {
    01206     uint pos = (DiagDirToAxis(GetTunnelBridgeDirection(tile)) == AXIS_X ? y : x);
    01207
    01208     /* In the tunnel entrance? */
    01209     if (5 <= pos && pos <= 10) return z;
    01210   } else { // IsBridge(tile)
    01211     DiagDirection dir = GetTunnelBridgeDirection(tile);
    01212     uint pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
    01213
    01214     z += ApplyFoundationToSlope(GetBridgeFoundation(tileh, DiagDirToAxis(dir)), &tileh);
    01215
    01216     /* On the bridge ramp? */
    01217     if (5 <= pos && pos <= 10) {
    01218       uint delta;
    01219
    01220       if (tileh != SLOPE_FLAT) return z + TILE_HEIGHT;
    01221
    01222       switch (dir) {
    01223         default: NOT_REACHED();
    01224         case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
    01225         case DIAGDIR_SE: delta = y / 2; break;
    01226         case DIAGDIR_SW: delta = x / 2; break;
    01227         case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
    01228       }
    01229       return z + 1 + delta;
    01230     }
    01231   }
    01232
    01233   return z + GetPartialZ(x, y, tileh);
    01234 }
    01235
    01236 static Foundation GetFoundation_TunnelBridge(TileIndex tile, Slope tileh)
    01237 {
    01238   return IsTunnel(tile) ? FOUNDATION_NONE : GetBridgeFoundation(tileh, DiagDirToAxis(GetTunnelBridgeDirection(tile)));
    01239 }
    01240
    01241 static void GetTileDesc_TunnelBridge(TileIndex tile, TileDesc *td)
    01242 {
    01243   TransportType tt = GetTunnelBridgeTransportType(tile);
    01244
    01245   if (IsTunnel(tile)) {
    01246     td->str = (tt == TRANSPORT_RAIL) ? STR_LAI_TUNNEL_DESCRIPTION_RAILROAD : STR_LAI_TUNNEL_DESCRIPTION_ROAD;
    01247   } else { // IsBridge(tile)
    01248     td->str = (tt == TRANSPORT_WATER) ? STR_LAI_BRIDGE_DESCRIPTION_AQUEDUCT : GetBridgeSpec(GetBridgeType(tile))->transport_name[tt];
    01249   }
    01250   td->owner[0] = GetTileOwner(tile);
    01251
    01252   Owner road_owner = INVALID_OWNER;
    01253   Owner tram_owner = INVALID_OWNER;
    01254   RoadTypes rts = GetRoadTypes(tile);
    01255   if (HasBit(rts, ROADTYPE_ROAD)) road_owner = GetRoadOwner(tile, ROADTYPE_ROAD);
    01256   if (HasBit(rts, ROADTYPE_TRAM)) tram_owner = GetRoadOwner(tile, ROADTYPE_TRAM);
    01257
    01258   /* Is there a mix of owners? */
    01259   if ((tram_owner != INVALID_OWNER && tram_owner != td->owner[0]) ||
    01260       (road_owner != INVALID_OWNER && road_owner != td->owner[0])) {
    01261     uint i = 1;
    01262     if (road_owner != INVALID_OWNER) {
    01263       td->owner_type[i] = STR_LAND_AREA_INFORMATION_ROAD_OWNER;
    01264       td->owner[i] = road_owner;
    01265       i++;
    01266     }
    01267     if (tram_owner != INVALID_OWNER) {
    01268       td->owner_type[i] = STR_LAND_AREA_INFORMATION_TRAM_OWNER;
    01269       td->owner[i] = tram_owner;
    01270     }
    01271   }
    01272 }
    01273
    01274
    01275 static void TileLoop_TunnelBridge(TileIndex tile)
    01276 {
    01277   bool snow_or_desert = HasTunnelBridgeSnowOrDesert(tile);
    01278   switch (_settings_game.game_creation.landscape) {
    01279     case LT_ARCTIC:
    01280       if (snow_or_desert != (GetTileZ(tile) > GetSnowLine())) {
    01281         SetTunnelBridgeSnowOrDesert(tile, !snow_or_desert);
    01282         MarkTileDirtyByTile(tile);
    01283       }
    01284       break;
    01285
    01286     case LT_TROPIC:
    01287       if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
    01288         SetTunnelBridgeSnowOrDesert(tile, true);
    01289         MarkTileDirtyByTile(tile);
    01290       }
    01291       break;
    01292
    01293     default:
    01294       break;
    01295   }
    01296 }
    01297
    01298 static TrackStatus GetTileTrackStatus_TunnelBridge(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
    01299 {
    01300   TransportType transport_type = GetTunnelBridgeTransportType(tile);
    01301   if (transport_type != mode || (transport_type == TRANSPORT_ROAD && (GetRoadTypes(tile) & sub_mode) == 0)) return 0;
    01302
    01303   DiagDirection dir = GetTunnelBridgeDirection(tile);
    01304   if (side != INVALID_DIAGDIR && side != ReverseDiagDir(dir)) return 0;
    01305   return CombineTrackStatus(TrackBitsToTrackdirBits(DiagDirToDiagTrackBits(dir)), TRACKDIR_BIT_NONE);
    01306 }
    01307
    01308 static void ChangeTileOwner_TunnelBridge(TileIndex tile, Owner old_owner, Owner new_owner)
    01309 {
    01310   for (RoadType rt = ROADTYPE_ROAD; rt < ROADTYPE_END; rt++) {
    01311     /* Update all roadtypes, no matter if they are present */
    01312     if (GetRoadOwner(tile, rt) == old_owner) {
    01313       SetRoadOwner(tile, rt, new_owner == INVALID_OWNER ? OWNER_NONE : new_owner);
    01314     }
    01315   }
    01316
    01317   if (!IsTileOwner(tile, old_owner)) return;
    01318
    01319   if (new_owner != INVALID_OWNER) {
    01320     SetTileOwner(tile, new_owner);
    01321   } else {
    01322     if (DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR).Failed()) {
    01323       /* When clearing the bridge/tunnel failed there are still vehicles on/in
    01324        * the bridge/tunnel. As all *our* vehicles are already removed, they
    01325        * must be of another owner. Therefore this can't be rail tunnel/bridge.
    01326        * In that case we can safely reassign the ownership to OWNER_NONE. */
    01327       assert(GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL);
    01328       SetTileOwner(tile, OWNER_NONE);
    01329     }
    01330   }
    01331 }
    01332
    01333
    01334 static const byte _tunnel_fractcoord_1[4]    = {0x8E, 0x18, 0x81, 0xE8};
    01335 static const byte _tunnel_fractcoord_2[4]    = {0x81, 0x98, 0x87, 0x38};
    01336 static const byte _tunnel_fractcoord_3[4]    = {0x82, 0x88, 0x86, 0x48};
    01337 static const byte _exit_tunnel_track[4]      = {1, 2, 1, 2};
    01338
    01340 static const Trackdir _road_exit_tunnel_state[DIAGDIR_END] = {
    01341   TRACKDIR_X_SW, TRACKDIR_Y_NW, TRACKDIR_X_NE, TRACKDIR_Y_SE
    01342 };
    01343 static const byte _road_exit_tunnel_frame[4] = {2, 7, 9, 4};
    01344
    01345 static const byte _tunnel_fractcoord_4[4]    = {0x52, 0x85, 0x98, 0x29};
    01346 static const byte _tunnel_fractcoord_5[4]    = {0x92, 0x89, 0x58, 0x25};
    01347 static const byte _tunnel_fractcoord_6[4]    = {0x92, 0x89, 0x56, 0x45};
    01348 static const byte _tunnel_fractcoord_7[4]    = {0x52, 0x85, 0x96, 0x49};
    01349
    01350 static VehicleEnterTileStatus VehicleEnter_TunnelBridge(Vehicle *v, TileIndex tile, int x, int y)
    01351 {
    01352   int z = GetSlopeZ(x, y) - v->z_pos;
    01353
    01354   if (abs(z) > 2) return VETSB_CANNOT_ENTER;
    01355   const DiagDirection dir = GetTunnelBridgeDirection(tile);
    01356
    01357   if (IsTunnel(tile)) {
    01358     byte fc;
    01359     DiagDirection vdir;
    01360
    01361     if (v->type == VEH_TRAIN) {
    01362       Train *t = Train::From(v);
    01363       fc = (x & 0xF) + (y << 4);
    01364
    01365       vdir = DirToDiagDir(t->direction);
    01366
    01367       if (t->track != TRACK_BIT_WORMHOLE && dir == vdir) {
    01368         if (t->IsFrontEngine() && fc == _tunnel_fractcoord_1[dir]) {
    01369           if (!PlayVehicleSound(t, VSE_TUNNEL) && RailVehInfo(t->engine_type)->engclass == 0) {
    01370             SndPlayVehicleFx(SND_05_TRAIN_THROUGH_TUNNEL, v);
    01371           }
    01372           return VETSB_CONTINUE;
    01373         }
    01374         if (fc == _tunnel_fractcoord_2[dir]) {
    01375           t->tile = tile;
    01376           t->track = TRACK_BIT_WORMHOLE;
    01377           t->vehstatus |= VS_HIDDEN;
    01378           return VETSB_ENTERED_WORMHOLE;
    01379         }
    01380       }
    01381
    01382       if (dir == ReverseDiagDir(vdir) && fc == _tunnel_fractcoord_3[dir] && z == 0) {
    01383         /* We're at the tunnel exit ?? */
    01384         t->tile = tile;
    01385         t->track = (TrackBits)_exit_tunnel_track[dir];
    01386         assert(t->track);
    01387         t->vehstatus &= ~VS_HIDDEN;
    01388         return VETSB_ENTERED_WORMHOLE;
    01389       }
    01390     } else if (v->type == VEH_ROAD) {
    01391       RoadVehicle *rv = RoadVehicle::From(v);
    01392       fc = (x & 0xF) + (y << 4);
    01393       vdir = DirToDiagDir(v->direction);
    01394
    01395       /* Enter tunnel? */
    01396       if (rv->state != RVSB_WORMHOLE && dir == vdir) {
    01397         if (fc == _tunnel_fractcoord_4[dir] ||
    01398             fc == _tunnel_fractcoord_5[dir]) {
    01399           rv->tile = tile;
    01400           rv->state = RVSB_WORMHOLE;
    01401           rv->vehstatus |= VS_HIDDEN;
    01402           return VETSB_ENTERED_WORMHOLE;
    01403         } else {
    01404           return VETSB_CONTINUE;
    01405         }
    01406       }
    01407
    01408       if (dir == ReverseDiagDir(vdir) && (
    01409             /* We're at the tunnel exit ?? */
    01410             fc == _tunnel_fractcoord_6[dir] ||
    01411             fc == _tunnel_fractcoord_7[dir]
    01412           ) &&
    01413           z == 0) {
    01414         rv->tile = tile;
    01415         rv->state = _road_exit_tunnel_state[dir];
    01416         rv->frame = _road_exit_tunnel_frame[dir];
    01417         rv->vehstatus &= ~VS_HIDDEN;
    01418         return VETSB_ENTERED_WORMHOLE;
    01419       }
    01420     }
    01421   } else { // IsBridge(tile)
    01422
    01423     if (v->IsPrimaryVehicle() && v->type != VEH_SHIP) {
    01424       /* modify speed of vehicle */
    01425       uint16 spd = GetBridgeSpec(GetBridgeType(tile))->speed;
    01426
    01427       if (v->type == VEH_ROAD) spd *= 2;
    01428       if (v->cur_speed > spd) v->cur_speed = spd;
    01429     }
    01430
    01431     if (DirToDiagDir(v->direction) == dir) {
    01432       switch (dir) {
    01433         default: NOT_REACHED();
    01434         case DIAGDIR_NE: if ((x & 0xF) != 0)             return VETSB_CONTINUE; break;
    01435         case DIAGDIR_SE: if ((y & 0xF) != TILE_SIZE - 1) return VETSB_CONTINUE; break;
    01436         case DIAGDIR_SW: if ((x & 0xF) != TILE_SIZE - 1) return VETSB_CONTINUE; break;
    01437         case DIAGDIR_NW: if ((y & 0xF) != 0)             return VETSB_CONTINUE; break;
    01438       }
    01439       switch (v->type) {
    01440         case VEH_TRAIN: {
    01441           Train *t = Train::From(v);
    01442           t->track = TRACK_BIT_WORMHOLE;
    01443           ClrBit(t->flags, VRF_GOINGUP);
    01444           ClrBit(t->flags, VRF_GOINGDOWN);
    01445         } break;
    01446
    01447         case VEH_ROAD:
    01448           RoadVehicle::From(v)->state = RVSB_WORMHOLE;
    01449           break;
    01450
    01451         case VEH_SHIP:
    01452           Ship::From(v)->state = TRACK_BIT_WORMHOLE;
    01453           break;
    01454
    01455         default: NOT_REACHED();
    01456       }
    01457       return VETSB_ENTERED_WORMHOLE;
    01458     } else if (DirToDiagDir(v->direction) == ReverseDiagDir(dir)) {
    01459       v->tile = tile;
    01460       switch (v->type) {
    01461         case VEH_TRAIN: {
    01462           Train *t = Train::From(v);
    01463           if (t->track == TRACK_BIT_WORMHOLE) {
    01464             t->track = (DiagDirToAxis(dir) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y);
    01465             return VETSB_ENTERED_WORMHOLE;
    01466           }
    01467         } break;
    01468
    01469         case VEH_ROAD: {
    01470           RoadVehicle *rv = RoadVehicle::From(v);
    01471           if (rv->state == RVSB_WORMHOLE) {
    01472             rv->state = _road_exit_tunnel_state[dir];
    01473             rv->frame = 0;
    01474             return VETSB_ENTERED_WORMHOLE;
    01475           }
    01476         } break;
    01477
    01478         case VEH_SHIP: {
    01479           Ship *ship = Ship::From(v);
    01480           if (ship->state == TRACK_BIT_WORMHOLE) {
    01481             ship->state = (DiagDirToAxis(dir) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y);
    01482             return VETSB_ENTERED_WORMHOLE;
    01483           }
    01484         } break;
    01485
    01486         default: NOT_REACHED();
    01487       }
    01488     }
    01489   }
    01490   return VETSB_CONTINUE;
    01491 }
    01492
    01493 static CommandCost TerraformTile_TunnelBridge(TileIndex tile, DoCommandFlag flags, uint z_new, Slope tileh_new)
    01494 {
    01495   if (_settings_game.construction.build_on_slopes && AutoslopeEnabled() && IsBridge(tile) && GetTunnelBridgeTransportType(tile) != TRANSPORT_WATER) {
    01496     DiagDirection direction = GetTunnelBridgeDirection(tile);
    01497     Axis axis = DiagDirToAxis(direction);
    01498     CommandCost res;
    01499     uint z_old;
    01500     Slope tileh_old = GetTileSlope(tile, &z_old);
    01501
    01502     /* Check if new slope is valid for bridges in general (so we can safely call GetBridgeFoundation()) */
    01503     if ((direction == DIAGDIR_NW) || (direction == DIAGDIR_NE)) {
    01504       CheckBridgeSlopeSouth(axis, &tileh_old, &z_old);
    01505       res = CheckBridgeSlopeSouth(axis, &tileh_new, &z_new);
    01506     } else {
    01507       CheckBridgeSlopeNorth(axis, &tileh_old, &z_old);
    01508       res = CheckBridgeSlopeNorth(axis, &tileh_new, &z_new);
    01509     }
    01510
    01511     /* Surface slope is valid and remains unchanged? */
    01512     if (res.Succeeded() && (z_old == z_new) && (tileh_old == tileh_new)) return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
    01513   }
    01514
    01515   return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
    01516 }
    01517
    01518 extern const TileTypeProcs _tile_type_tunnelbridge_procs = {
    01519   DrawTile_TunnelBridge,           // draw_tile_proc
    01520   GetSlopeZ_TunnelBridge,          // get_slope_z_proc
    01521   ClearTile_TunnelBridge,          // clear_tile_proc
    01522   NULL,                            // add_accepted_cargo_proc
    01523   GetTileDesc_TunnelBridge,        // get_tile_desc_proc
    01524   GetTileTrackStatus_TunnelBridge, // get_tile_track_status_proc
    01525   NULL,                            // click_tile_proc
    01526   NULL,                            // animate_tile_proc
    01527   TileLoop_TunnelBridge,           // tile_loop_clear
    01528   ChangeTileOwner_TunnelBridge,    // change_tile_owner_clear
    01529   NULL,                            // add_produced_cargo_proc
    01530   VehicleEnter_TunnelBridge,       // vehicle_enter_tile_proc
    01531   GetFoundation_TunnelBridge,      // get_foundation_proc
    01532   TerraformTile_TunnelBridge,      // terraform_tile_proc
    01533 };