rail_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 
00012 #include "stdafx.h"
00013 #include "cmd_helper.h"
00014 #include "viewport_func.h"
00015 #include "command_func.h"
00016 #include "depot_base.h"
00017 #include "pathfinder/yapf/yapf_cache.h"
00018 #include "newgrf_debug.h"
00019 #include "newgrf_railtype.h"
00020 #include "train.h"
00021 #include "autoslope.h"
00022 #include "water.h"
00023 #include "tunnelbridge_map.h"
00024 #include "window_func.h"
00025 #include "vehicle_func.h"
00026 #include "sound_func.h"
00027 #include "tunnelbridge.h"
00028 #include "elrail_func.h"
00029 #include "town.h"
00030 #include "pbs.h"
00031 #include "company_base.h"
00032 #include "core/backup_type.hpp"
00033 #include "date_func.h"
00034 #include "programmable_signals.h"
00035 #include "company_gui.h"
00036 
00037 #include "table/strings.h"
00038 #include "table/railtypes.h"
00039 #include "table/track_land.h"
00040 
00042 typedef SmallVector<Train *, 16> TrainList;
00043 
00044 RailtypeInfo _railtypes[RAILTYPE_END];
00045 
00046 assert_compile(sizeof(_original_railtypes) <= sizeof(_railtypes));
00047 
00051 void ResetRailTypes()
00052 {
00053   memset(_railtypes, 0, sizeof(_railtypes));
00054   memcpy(_railtypes, _original_railtypes, sizeof(_original_railtypes));
00055 }
00056 
00057 void ResolveRailTypeGUISprites(RailtypeInfo *rti)
00058 {
00059   SpriteID cursors_base = GetCustomRailSprite(rti, INVALID_TILE, RTSG_CURSORS);
00060   if (cursors_base != 0) {
00061     rti->gui_sprites.build_ns_rail = cursors_base +  0;
00062     rti->gui_sprites.build_x_rail  = cursors_base +  1;
00063     rti->gui_sprites.build_ew_rail = cursors_base +  2;
00064     rti->gui_sprites.build_y_rail  = cursors_base +  3;
00065     rti->gui_sprites.auto_rail     = cursors_base +  4;
00066     rti->gui_sprites.build_depot   = cursors_base +  5;
00067     rti->gui_sprites.build_tunnel  = cursors_base +  6;
00068     rti->gui_sprites.convert_rail  = cursors_base +  7;
00069     rti->cursor.rail_ns   = cursors_base +  8;
00070     rti->cursor.rail_swne = cursors_base +  9;
00071     rti->cursor.rail_ew   = cursors_base + 10;
00072     rti->cursor.rail_nwse = cursors_base + 11;
00073     rti->cursor.autorail  = cursors_base + 12;
00074     rti->cursor.depot     = cursors_base + 13;
00075     rti->cursor.tunnel    = cursors_base + 14;
00076     rti->cursor.convert   = cursors_base + 15;
00077   }
00078 }
00079 
00083 void InitRailTypes()
00084 {
00085   for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
00086     RailtypeInfo *rti = &_railtypes[rt];
00087     ResolveRailTypeGUISprites(rti);
00088   }
00089 }
00090 
00094 RailType AllocateRailType(RailTypeLabel label)
00095 {
00096   for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
00097     RailtypeInfo *rti = &_railtypes[rt];
00098 
00099     if (rti->label == 0) {
00100       /* Set up new rail type */
00101       memcpy(rti, &_railtypes[RAILTYPE_RAIL], sizeof(*rti));
00102       rti->label = label;
00103 
00104       /* Make us compatible with ourself. */
00105       rti->powered_railtypes    = (RailTypes)(1 << rt);
00106       rti->compatible_railtypes = (RailTypes)(1 << rt);
00107 
00108       /* We also introduce ourself. */
00109       rti->introduces_railtypes = (RailTypes)(1 << rt);
00110 
00111       /* Default sort order; order of allocation, but with some
00112        * offsets so it's easier for NewGRF to pick a spot without
00113        * changing the order of other (original) rail types.
00114        * The << is so you can place other railtypes in between the
00115        * other railtypes, the 7 is to be able to place something
00116        * before the first (default) rail type. */
00117       rti->sorting_order = rt << 4 | 7;
00118       return rt;
00119     }
00120   }
00121 
00122   return INVALID_RAILTYPE;
00123 }
00124 
00125 static const byte _track_sloped_sprites[14] = {
00126   14, 15, 22, 13,
00127    0, 21, 17, 12,
00128   23,  0, 18, 20,
00129   19, 16
00130 };
00131 
00132 
00133 /*         4
00134  *     ---------
00135  *    |\       /|
00136  *    | \    1/ |
00137  *    |  \   /  |
00138  *    |   \ /   |
00139  *  16|    \    |32
00140  *    |   / \2  |
00141  *    |  /   \  |
00142  *    | /     \ |
00143  *    |/       \|
00144  *     ---------
00145  *         8
00146  */
00147 
00148 
00149 
00150 /* MAP2 byte:    abcd???? => Signal On? Same coding as map3lo
00151  * MAP3LO byte:  abcd???? => Signal Exists?
00152  *               a and b are for diagonals, upper and left,
00153  *               one for each direction. (ie a == NE->SW, b ==
00154  *               SW->NE, or v.v., I don't know. b and c are
00155  *               similar for lower and right.
00156  * MAP2 byte:    ????abcd => Type of ground.
00157  * MAP3LO byte:  ????abcd => Type of rail.
00158  * MAP5:         00abcdef => rail
00159  *               01abcdef => rail w/ signals
00160  *               10uuuuuu => unused
00161  *               11uuuudd => rail depot
00162  */
00163 
00172 static CommandCost EnsureNoTrainOnTrack(TileIndex tile, Track track)
00173 {
00174   TrackBits rail_bits = TrackToTrackBits(track);
00175   return EnsureNoTrainOnTrackBits(tile, rail_bits);
00176 }
00177 
00185 static CommandCost CheckTrackCombination(TileIndex tile, TrackBits to_build, uint flags)
00186 {
00187   if (!IsPlainRail(tile)) return_cmd_error(STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION);
00188 
00189   /* So, we have a tile with tracks on it (and possibly signals). Let's see
00190    * what tracks first */
00191   TrackBits current = GetTrackBits(tile); // The current track layout.
00192   TrackBits future = current | to_build;  // The track layout we want to build.
00193 
00194   /* Are we really building something new? */
00195   if (current == future) {
00196     /* Nothing new is being built */
00197     return_cmd_error(STR_ERROR_ALREADY_BUILT);
00198   }
00199 
00200   /* Let's see if we may build this */
00201   if ((flags & DC_NO_RAIL_OVERLAP) || HasSignals(tile)) {
00202     /* If we are not allowed to overlap (flag is on for ai companies or we have
00203      * signals on the tile), check that */
00204     if (future != TRACK_BIT_HORZ && future != TRACK_BIT_VERT) {
00205       return_cmd_error((flags & DC_NO_RAIL_OVERLAP) ? STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION : STR_ERROR_MUST_REMOVE_SIGNALS_FIRST);
00206     }
00207   }
00208   /* Normally, we may overlap and any combination is valid */
00209   return CommandCost();
00210 }
00211 
00212 
00214 static const TrackBits _valid_tracks_without_foundation[15] = {
00215   TRACK_BIT_ALL,
00216   TRACK_BIT_RIGHT,
00217   TRACK_BIT_UPPER,
00218   TRACK_BIT_X,
00219 
00220   TRACK_BIT_LEFT,
00221   TRACK_BIT_NONE,
00222   TRACK_BIT_Y,
00223   TRACK_BIT_LOWER,
00224 
00225   TRACK_BIT_LOWER,
00226   TRACK_BIT_Y,
00227   TRACK_BIT_NONE,
00228   TRACK_BIT_LEFT,
00229 
00230   TRACK_BIT_X,
00231   TRACK_BIT_UPPER,
00232   TRACK_BIT_RIGHT,
00233 };
00234 
00236 static const TrackBits _valid_tracks_on_leveled_foundation[15] = {
00237   TRACK_BIT_NONE,
00238   TRACK_BIT_LEFT,
00239   TRACK_BIT_LOWER,
00240   TRACK_BIT_Y | TRACK_BIT_LOWER | TRACK_BIT_LEFT,
00241 
00242   TRACK_BIT_RIGHT,
00243   TRACK_BIT_ALL,
00244   TRACK_BIT_X | TRACK_BIT_LOWER | TRACK_BIT_RIGHT,
00245   TRACK_BIT_ALL,
00246 
00247   TRACK_BIT_UPPER,
00248   TRACK_BIT_X | TRACK_BIT_UPPER | TRACK_BIT_LEFT,
00249   TRACK_BIT_ALL,
00250   TRACK_BIT_ALL,
00251 
00252   TRACK_BIT_Y | TRACK_BIT_UPPER | TRACK_BIT_RIGHT,
00253   TRACK_BIT_ALL,
00254   TRACK_BIT_ALL
00255 };
00256 
00264 Foundation GetRailFoundation(Slope tileh, TrackBits bits)
00265 {
00266   if (bits == TRACK_BIT_NONE) return FOUNDATION_NONE;
00267 
00268   if (IsSteepSlope(tileh)) {
00269     /* Test for inclined foundations */
00270     if (bits == TRACK_BIT_X) return FOUNDATION_INCLINED_X;
00271     if (bits == TRACK_BIT_Y) return FOUNDATION_INCLINED_Y;
00272 
00273     /* Get higher track */
00274     Corner highest_corner = GetHighestSlopeCorner(tileh);
00275     TrackBits higher_track = CornerToTrackBits(highest_corner);
00276 
00277     /* Only higher track? */
00278     if (bits == higher_track) return HalftileFoundation(highest_corner);
00279 
00280     /* Overlap with higher track? */
00281     if (TracksOverlap(bits | higher_track)) return FOUNDATION_INVALID;
00282 
00283     /* either lower track or both higher and lower track */
00284     return ((bits & higher_track) != 0 ? FOUNDATION_STEEP_BOTH : FOUNDATION_STEEP_LOWER);
00285   } else {
00286     if ((~_valid_tracks_without_foundation[tileh] & bits) == 0) return FOUNDATION_NONE;
00287 
00288     bool valid_on_leveled = ((~_valid_tracks_on_leveled_foundation[tileh] & bits) == 0);
00289 
00290     Corner track_corner;
00291     switch (bits) {
00292       case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
00293       case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
00294       case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
00295       case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
00296 
00297       case TRACK_BIT_HORZ:
00298         if (tileh == SLOPE_N) return HalftileFoundation(CORNER_N);
00299         if (tileh == SLOPE_S) return HalftileFoundation(CORNER_S);
00300         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00301 
00302       case TRACK_BIT_VERT:
00303         if (tileh == SLOPE_W) return HalftileFoundation(CORNER_W);
00304         if (tileh == SLOPE_E) return HalftileFoundation(CORNER_E);
00305         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00306 
00307       case TRACK_BIT_X:
00308         if (IsSlopeWithOneCornerRaised(tileh)) return FOUNDATION_INCLINED_X;
00309         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00310 
00311       case TRACK_BIT_Y:
00312         if (IsSlopeWithOneCornerRaised(tileh)) return FOUNDATION_INCLINED_Y;
00313         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00314 
00315       default:
00316         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00317     }
00318     /* Single diagonal track */
00319 
00320     /* Track must be at least valid on leveled foundation */
00321     if (!valid_on_leveled) return FOUNDATION_INVALID;
00322 
00323     /* If slope has three raised corners, build leveled foundation */
00324     if (IsSlopeWithThreeCornersRaised(tileh)) return FOUNDATION_LEVELED;
00325 
00326     /* If neighboured corners of track_corner are lowered, build halftile foundation */
00327     if ((tileh & SlopeWithThreeCornersRaised(OppositeCorner(track_corner))) == SlopeWithOneCornerRaised(track_corner)) return HalftileFoundation(track_corner);
00328 
00329     /* else special anti-zig-zag foundation */
00330     return SpecialRailFoundation(track_corner);
00331   }
00332 }
00333 
00334 
00344 static CommandCost CheckRailSlope(Slope tileh, TrackBits rail_bits, TrackBits existing, TileIndex tile)
00345 {
00346   /* don't allow building on the lower side of a coast */
00347   if (GetFloodingBehaviour(tile) != FLOOD_NONE) {
00348     if (!IsSteepSlope(tileh) && ((~_valid_tracks_on_leveled_foundation[tileh] & (rail_bits | existing)) != 0)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
00349   }
00350 
00351   Foundation f_new = GetRailFoundation(tileh, rail_bits | existing);
00352 
00353   /* check track/slope combination */
00354   if ((f_new == FOUNDATION_INVALID) ||
00355       ((f_new != FOUNDATION_NONE) && (!_settings_game.construction.build_on_slopes))) {
00356     return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00357   }
00358 
00359   Foundation f_old = GetRailFoundation(tileh, existing);
00360   return CommandCost(EXPENSES_CONSTRUCTION, f_new != f_old ? _price[PR_BUILD_FOUNDATION] : (Money)0);
00361 }
00362 
00363 /* Validate functions for rail building */
00364 static inline bool ValParamTrackOrientation(Track track)
00365 {
00366   return IsValidTrack(track);
00367 }
00368 
00378 CommandCost CmdBuildSingleRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00379 {
00380   RailType railtype = Extract<RailType, 0, 4>(p1);
00381   Track track = Extract<Track, 0, 3>(p2);
00382   CommandCost cost(EXPENSES_CONSTRUCTION);
00383 
00384   if (!ValParamRailtype(railtype) || !ValParamTrackOrientation(track)) return CMD_ERROR;
00385 
00386   Slope tileh = GetTileSlope(tile, NULL);
00387   TrackBits trackbit = TrackToTrackBits(track);
00388 
00389   switch (GetTileType(tile)) {
00390     case MP_RAILWAY: {
00391       CommandCost ret = CheckTileOwnership(tile);
00392       if (ret.Failed()) return ret;
00393 
00394       if (!IsPlainRail(tile)) return CMD_ERROR;
00395 
00396       if (!IsCompatibleRail(GetRailType(tile), railtype)) return_cmd_error(STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION);
00397 
00398       ret = CheckTrackCombination(tile, trackbit, flags);
00399       if (ret.Succeeded()) ret = EnsureNoTrainOnTrack(tile, track);
00400       if (ret.Failed()) return ret;
00401 
00402       ret = CheckRailSlope(tileh, trackbit, GetTrackBits(tile), tile);
00403       if (ret.Failed()) return ret;
00404       cost.AddCost(ret);
00405 
00406       /* If the rail types don't match, try to convert only if engines of
00407        * the new rail type are not powered on the present rail type and engines of
00408        * the present rail type are powered on the new rail type. */
00409       if (GetRailType(tile) != railtype && !HasPowerOnRail(railtype, GetRailType(tile))) {
00410         if (HasPowerOnRail(GetRailType(tile), railtype)) {
00411           ret = DoCommand(tile, tile, railtype, flags, CMD_CONVERT_RAIL);
00412           if (ret.Failed()) return ret;
00413           cost.AddCost(ret);
00414         } else {
00415           return CMD_ERROR;
00416         }
00417       }
00418 
00419       if (flags & DC_EXEC) {
00420         SetRailGroundType(tile, RAIL_GROUND_BARREN);
00421         TrackBits bits = GetTrackBits(tile);
00422         SetTrackBits(tile, bits | trackbit);
00423         /* Subtract old infrastructure count. */
00424         uint pieces = CountBits(bits);
00425         if (TracksOverlap(bits)) pieces *= pieces;
00426         Company::Get(GetTileOwner(tile))->rail_infrastructure[GetRailType(tile)] -= pieces;
00427         /* Add new infrastructure count. */
00428         pieces = CountBits(bits | trackbit);
00429         if (TracksOverlap(bits | trackbit)) pieces *= pieces;
00430         Company::Get(GetTileOwner(tile))->rail_infrastructure[GetRailType(tile)] += pieces;
00431         DirtyCompanyInfrastructureWindows(GetTileOwner(tile));
00432       }
00433       break;
00434     }
00435 
00436     case MP_ROAD: {
00437       /* Level crossings may only be built on these slopes */
00438       if (!HasBit(VALID_LEVEL_CROSSING_SLOPES, tileh)) return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00439 
00440       CommandCost ret = EnsureNoVehicleOnGround(tile);
00441       if (ret.Failed()) return ret;
00442 
00443       if (IsNormalRoad(tile)) {
00444         if (HasRoadWorks(tile)) return_cmd_error(STR_ERROR_ROAD_WORKS_IN_PROGRESS);
00445 
00446         if (GetDisallowedRoadDirections(tile) != DRD_NONE) return_cmd_error(STR_ERROR_CROSSING_ON_ONEWAY_ROAD);
00447 
00448         if (RailNoLevelCrossings(railtype)) return_cmd_error(STR_ERROR_CROSSING_DISALLOWED);
00449 
00450         RoadTypes roadtypes = GetRoadTypes(tile);
00451         RoadBits road = GetRoadBits(tile, ROADTYPE_ROAD);
00452         RoadBits tram = GetRoadBits(tile, ROADTYPE_TRAM);
00453         switch (roadtypes) {
00454           default: break;
00455           case ROADTYPES_TRAM:
00456             /* Tram crossings must always have road. */
00457             if (flags & DC_EXEC) {
00458               SetRoadOwner(tile, ROADTYPE_ROAD, _current_company);
00459               Company *c = Company::GetIfValid(_current_company);
00460               if (c != NULL) {
00461                 /* A full diagonal tile has two road bits. */
00462                 c->road_infrastructure[ROADTYPE_ROAD] += 2;
00463                 DirtyCompanyInfrastructureWindows(c->index);
00464               }
00465             }
00466             roadtypes |= ROADTYPES_ROAD;
00467             break;
00468 
00469           case ROADTYPES_ALL:
00470             if (road != tram) return CMD_ERROR;
00471             break;
00472         }
00473 
00474         road |= tram;
00475 
00476         if ((track == TRACK_X && road == ROAD_Y) ||
00477             (track == TRACK_Y && road == ROAD_X)) {
00478           if (flags & DC_EXEC) {
00479             MakeRoadCrossing(tile, GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM), _current_company, (track == TRACK_X ? AXIS_Y : AXIS_X), railtype, roadtypes, GetTownIndex(tile));
00480             UpdateLevelCrossing(tile, false);
00481             Company::Get(_current_company)->rail_infrastructure[railtype] += LEVELCROSSING_TRACKBIT_FACTOR;
00482             DirtyCompanyInfrastructureWindows(_current_company);
00483           }
00484           break;
00485         }
00486       }
00487 
00488       if (IsLevelCrossing(tile) && GetCrossingRailBits(tile) == trackbit) {
00489         return_cmd_error(STR_ERROR_ALREADY_BUILT);
00490       }
00491       /* FALL THROUGH */
00492     }
00493 
00494     default: {
00495       /* Will there be flat water on the lower halftile? */
00496       bool water_ground = IsTileType(tile, MP_WATER) && IsSlopeWithOneCornerRaised(tileh);
00497 
00498       CommandCost ret = CheckRailSlope(tileh, trackbit, TRACK_BIT_NONE, tile);
00499       if (ret.Failed()) return ret;
00500       cost.AddCost(ret);
00501 
00502       ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00503       if (ret.Failed()) return ret;
00504       cost.AddCost(ret);
00505 
00506       if (water_ground) {
00507         cost.AddCost(-_price[PR_CLEAR_WATER]);
00508         cost.AddCost(_price[PR_CLEAR_ROUGH]);
00509       }
00510 
00511       if (flags & DC_EXEC) {
00512         MakeRailNormal(tile, _current_company, trackbit, railtype);
00513         if (water_ground) SetRailGroundType(tile, RAIL_GROUND_WATER);
00514         Company::Get(_current_company)->rail_infrastructure[railtype]++;
00515         DirtyCompanyInfrastructureWindows(_current_company);
00516       }
00517       break;
00518     }
00519   }
00520 
00521   if (flags & DC_EXEC) {
00522     MarkTileDirtyByTile(tile);
00523     AddTrackToSignalBuffer(tile, track, _current_company);
00524     YapfNotifyTrackLayoutChange(tile, track);
00525   }
00526 
00527   cost.AddCost(RailBuildCost(railtype));
00528   return cost;
00529 }
00530 
00540 CommandCost CmdRemoveSingleRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00541 {
00542   Track track = Extract<Track, 0, 3>(p2);
00543   CommandCost cost(EXPENSES_CONSTRUCTION);
00544   bool crossing = false;
00545 
00546   if (!ValParamTrackOrientation(track)) return CMD_ERROR;
00547   TrackBits trackbit = TrackToTrackBits(track);
00548 
00549   /* Need to read tile owner now because it may change when the rail is removed
00550    * Also, in case of floods, _current_company != owner
00551    * There may be invalid tiletype even in exec run (when removing long track),
00552    * so do not call GetTileOwner(tile) in any case here */
00553   Owner owner = INVALID_OWNER;
00554 
00555   Train *v = NULL;
00556 
00557   switch (GetTileType(tile)) {
00558     case MP_ROAD: {
00559       if (!IsLevelCrossing(tile) || GetCrossingRailBits(tile) != trackbit) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00560 
00561       if (_current_company != OWNER_WATER) {
00562         CommandCost ret = CheckTileOwnership(tile);
00563         if (ret.Failed()) return ret;
00564       }
00565 
00566       if (!(flags & DC_BANKRUPT)) {
00567         CommandCost ret = EnsureNoVehicleOnGround(tile);
00568         if (ret.Failed()) return ret;
00569       }
00570 
00571       cost.AddCost(RailClearCost(GetRailType(tile)));
00572 
00573       if (flags & DC_EXEC) {
00574         if (HasReservedTracks(tile, trackbit)) {
00575           v = GetTrainForReservation(tile, track);
00576           if (v != NULL) FreeTrainTrackReservation(v);
00577         }
00578         owner = GetTileOwner(tile);
00579         Company::Get(owner)->rail_infrastructure[GetRailType(tile)] -= LEVELCROSSING_TRACKBIT_FACTOR;
00580         DirtyCompanyInfrastructureWindows(owner);
00581         MakeRoadNormal(tile, GetCrossingRoadBits(tile), GetRoadTypes(tile), GetTownIndex(tile), GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM));
00582         DeleteNewGRFInspectWindow(GSF_RAILTYPES, tile);
00583       }
00584       break;
00585     }
00586 
00587     case MP_RAILWAY: {
00588       TrackBits present;
00589       /* There are no rails present at depots. */
00590       if (!IsPlainRail(tile)) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00591 
00592       if (_current_company != OWNER_WATER) {
00593         CommandCost ret = CheckTileOwnership(tile);
00594         if (ret.Failed()) return ret;
00595       }
00596 
00597       CommandCost ret = EnsureNoTrainOnTrack(tile, track);
00598       if (ret.Failed()) return ret;
00599 
00600       present = GetTrackBits(tile);
00601       if ((present & trackbit) == 0) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00602       if (present == (TRACK_BIT_X | TRACK_BIT_Y)) crossing = true;
00603 
00604       cost.AddCost(RailClearCost(GetRailType(tile)));
00605 
00606       /* Charge extra to remove signals on the track, if they are there */
00607       if (HasSignalOnTrack(tile, track)) {
00608         /* If track has an exit signal on it dissalow removal. */
00609 // Todo: Check if this exit signal has a dependancy or , if it is a progsig, depends on another exit signal. Allow removal if none of both is true.
00610 //       Removing the dependency or the being dependant upon flag would work equally well here ...
00611         if (IsPresignalExit(tile, track)) {
00612           return_cmd_error(STR_ERROR_MUST_REMOVE_EXIT_SIGNALS_FIRST);
00613         } else {
00614           CheckRemoveSignal(tile, track);
00615           cost.AddCost(DoCommand(tile, track, 0, flags, CMD_REMOVE_SIGNALS));
00616         }
00617       }
00618 
00619       if (flags & DC_EXEC) {
00620         if (HasReservedTracks(tile, trackbit)) {
00621           v = GetTrainForReservation(tile, track);
00622           if (v != NULL) FreeTrainTrackReservation(v);
00623         }
00624 
00625         owner = GetTileOwner(tile);
00626 
00627         /* Subtract old infrastructure count. */
00628         uint pieces = CountBits(present);
00629         if (TracksOverlap(present)) pieces *= pieces;
00630         Company::Get(owner)->rail_infrastructure[GetRailType(tile)] -= pieces;
00631         /* Add new infrastructure count. */
00632         present ^= trackbit;
00633         pieces = CountBits(present);
00634         if (TracksOverlap(present)) pieces *= pieces;
00635         Company::Get(owner)->rail_infrastructure[GetRailType(tile)] += pieces;
00636         DirtyCompanyInfrastructureWindows(owner);
00637 
00638         if (present == 0) {
00639           Slope tileh = GetTileSlope(tile, NULL);
00640           /* If there is flat water on the lower halftile, convert the tile to shore so the water remains */
00641           if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh)) {
00642             MakeShore(tile);
00643           } else {
00644             DoClearSquare(tile);
00645           }
00646           DeleteNewGRFInspectWindow(GSF_RAILTYPES, tile);
00647         } else {
00648           SetTrackBits(tile, present);
00649           SetTrackReservation(tile, GetRailReservationTrackBits(tile) & present);
00650         }
00651       }
00652       break;
00653     }
00654 
00655     default: return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00656   }
00657 
00658   if (flags & DC_EXEC) {
00659     /* if we got that far, 'owner' variable is set correctly */
00660     assert(Company::IsValidID(owner));
00661 
00662     MarkTileDirtyByTile(tile);
00663     if (crossing) {
00664       /* crossing is set when only TRACK_BIT_X and TRACK_BIT_Y are set. As we
00665        * are removing one of these pieces, we'll need to update signals for
00666        * both directions explicitly, as after the track is removed it won't
00667        * 'connect' with the other piece. */
00668       AddTrackToSignalBuffer(tile, TRACK_X, owner);
00669       AddTrackToSignalBuffer(tile, TRACK_Y, owner);
00670       YapfNotifyTrackLayoutChange(tile, TRACK_X);
00671       YapfNotifyTrackLayoutChange(tile, TRACK_Y);
00672     } else {
00673       AddTrackToSignalBuffer(tile, track, owner);
00674       YapfNotifyTrackLayoutChange(tile, track);
00675     }
00676 
00677     if (v != NULL) TryPathReserve(v, true);
00678   }
00679 
00680   return cost;
00681 }
00682 
00683 
00691 bool FloodHalftile(TileIndex t)
00692 {
00693   assert(IsPlainRailTile(t));
00694 
00695   bool flooded = false;
00696   if (GetRailGroundType(t) == RAIL_GROUND_WATER) return flooded;
00697 
00698   Slope tileh = GetTileSlope(t, NULL);
00699   TrackBits rail_bits = GetTrackBits(t);
00700 
00701   if (IsSlopeWithOneCornerRaised(tileh)) {
00702     TrackBits lower_track = CornerToTrackBits(OppositeCorner(GetHighestSlopeCorner(tileh)));
00703 
00704     TrackBits to_remove = lower_track & rail_bits;
00705     if (to_remove != 0) {
00706       Backup<CompanyByte> cur_company(_current_company, OWNER_WATER, FILE_LINE);
00707       flooded = DoCommand(t, 0, FIND_FIRST_BIT(to_remove), DC_EXEC, CMD_REMOVE_SINGLE_RAIL).Succeeded();
00708       cur_company.Restore();
00709       if (!flooded) return flooded; // not yet floodable
00710       rail_bits = rail_bits & ~to_remove;
00711       if (rail_bits == 0) {
00712         MakeShore(t);
00713         MarkTileDirtyByTile(t);
00714         return flooded;
00715       }
00716     }
00717 
00718     if (IsNonContinuousFoundation(GetRailFoundation(tileh, rail_bits))) {
00719       flooded = true;
00720       SetRailGroundType(t, RAIL_GROUND_WATER);
00721       MarkTileDirtyByTile(t);
00722     }
00723   } else {
00724     /* Make shore on steep slopes and 'three-corners-raised'-slopes. */
00725     if (ApplyFoundationToSlope(GetRailFoundation(tileh, rail_bits), &tileh) == 0) {
00726       if (IsSteepSlope(tileh) || IsSlopeWithThreeCornersRaised(tileh)) {
00727         flooded = true;
00728         SetRailGroundType(t, RAIL_GROUND_WATER);
00729         MarkTileDirtyByTile(t);
00730       }
00731     }
00732   }
00733   return flooded;
00734 }
00735 
00736 static const TileIndexDiffC _trackdelta[] = {
00737   { -1,  0 }, {  0,  1 }, { -1,  0 }, {  0,  1 }, {  1,  0 }, {  0,  1 },
00738   {  0,  0 },
00739   {  0,  0 },
00740   {  1,  0 }, {  0, -1 }, {  0, -1 }, {  1,  0 }, {  0, -1 }, { -1,  0 },
00741   {  0,  0 },
00742   {  0,  0 }
00743 };
00744 
00745 
00746 static CommandCost ValidateAutoDrag(Trackdir *trackdir, TileIndex start, TileIndex end)
00747 {
00748   int x = TileX(start);
00749   int y = TileY(start);
00750   int ex = TileX(end);
00751   int ey = TileY(end);
00752 
00753   if (!ValParamTrackOrientation(TrackdirToTrack(*trackdir))) return CMD_ERROR;
00754 
00755   /* calculate delta x,y from start to end tile */
00756   int dx = ex - x;
00757   int dy = ey - y;
00758 
00759   /* calculate delta x,y for the first direction */
00760   int trdx = _trackdelta[*trackdir].x;
00761   int trdy = _trackdelta[*trackdir].y;
00762 
00763   if (!IsDiagonalTrackdir(*trackdir)) {
00764     trdx += _trackdelta[*trackdir ^ 1].x;
00765     trdy += _trackdelta[*trackdir ^ 1].y;
00766   }
00767 
00768   /* validate the direction */
00769   while ((trdx <= 0 && dx > 0) ||
00770       (trdx >= 0 && dx < 0) ||
00771       (trdy <= 0 && dy > 0) ||
00772       (trdy >= 0 && dy < 0)) {
00773     if (!HasBit(*trackdir, 3)) { // first direction is invalid, try the other
00774       SetBit(*trackdir, 3); // reverse the direction
00775       trdx = -trdx;
00776       trdy = -trdy;
00777     } else { // other direction is invalid too, invalid drag
00778       return CMD_ERROR;
00779     }
00780   }
00781 
00782   /* (for diagonal tracks, this is already made sure of by above test), but:
00783    * for non-diagonal tracks, check if the start and end tile are on 1 line */
00784   if (!IsDiagonalTrackdir(*trackdir)) {
00785     trdx = _trackdelta[*trackdir].x;
00786     trdy = _trackdelta[*trackdir].y;
00787     if (abs(dx) != abs(dy) && abs(dx) + abs(trdy) != abs(dy) + abs(trdx)) return CMD_ERROR;
00788   }
00789 
00790   return CommandCost();
00791 }
00792 
00806 static CommandCost CmdRailTrackHelper(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00807 {
00808   CommandCost total_cost(EXPENSES_CONSTRUCTION);
00809   Track track = Extract<Track, 4, 3>(p2);
00810   bool remove = HasBit(p2, 7);
00811   RailType railtype = Extract<RailType, 0, 4>(p2);
00812 
00813   if (!ValParamRailtype(railtype) || !ValParamTrackOrientation(track)) return CMD_ERROR;
00814   if (p1 >= MapSize()) return CMD_ERROR;
00815   TileIndex end_tile = p1;
00816   Trackdir trackdir = TrackToTrackdir(track);
00817 
00818   CommandCost ret = ValidateAutoDrag(&trackdir, tile, end_tile);
00819   if (ret.Failed()) return ret;
00820 
00821   if (flags & DC_EXEC) SndPlayTileFx(SND_20_SPLAT_2, tile);
00822 
00823   bool had_success = false;
00824   CommandCost last_error = CMD_ERROR;
00825   for (;;) {
00826     CommandCost ret = DoCommand(tile, railtype, TrackdirToTrack(trackdir), flags, remove ? CMD_REMOVE_SINGLE_RAIL : CMD_BUILD_SINGLE_RAIL);
00827 
00828     if (ret.Failed()) {
00829       last_error = ret;
00830       if (last_error.GetErrorMessage() != STR_ERROR_ALREADY_BUILT && !remove) {
00831         if (HasBit(p2, 8)) return last_error;
00832         break;
00833       }
00834 
00835       /* Ownership errors are more important. */
00836       if (last_error.GetErrorMessage() == STR_ERROR_OWNED_BY && remove) break;
00837     } else {
00838       had_success = true;
00839       total_cost.AddCost(ret);
00840     }
00841 
00842     if (tile == end_tile) break;
00843 
00844     tile += ToTileIndexDiff(_trackdelta[trackdir]);
00845 
00846     /* toggle railbit for the non-diagonal tracks */
00847     if (!IsDiagonalTrackdir(trackdir)) ToggleBit(trackdir, 0);
00848   }
00849 
00850   if (had_success) return total_cost;
00851   return last_error;
00852 }
00853 
00868 CommandCost CmdBuildRailroadTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00869 {
00870   return CmdRailTrackHelper(tile, flags, p1, ClrBit(p2, 7), text);
00871 }
00872 
00887 CommandCost CmdRemoveRailroadTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00888 {
00889   return CmdRailTrackHelper(tile, flags, p1, SetBit(p2, 7), text);
00890 }
00891 
00904 CommandCost CmdBuildTrainDepot(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00905 {
00906   /* check railtype and valid direction for depot (0 through 3), 4 in total */
00907   RailType railtype = Extract<RailType, 0, 4>(p1);
00908   if (!ValParamRailtype(railtype)) return CMD_ERROR;
00909 
00910   Slope tileh = GetTileSlope(tile, NULL);
00911 
00912   DiagDirection dir = Extract<DiagDirection, 0, 2>(p2);
00913 
00914   /* Prohibit construction if
00915    * The tile is non-flat AND
00916    * 1) build-on-slopes is disabled
00917    * 2) the tile is steep i.e. spans two height levels
00918    * 3) the exit points in the wrong direction
00919    */
00920 
00921   if (tileh != SLOPE_FLAT && (
00922         !_settings_game.construction.build_on_slopes ||
00923         IsSteepSlope(tileh) ||
00924         !CanBuildDepotByTileh(dir, tileh)
00925       )) {
00926     return_cmd_error(STR_ERROR_FLAT_LAND_REQUIRED);
00927   }
00928 
00929   CommandCost cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00930   if (cost.Failed()) return cost;
00931 
00932   if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00933 
00934   if (!Depot::CanAllocateItem()) return CMD_ERROR;
00935 
00936   if (flags & DC_EXEC) {
00937     Depot *d = new Depot(tile);
00938     d->build_date = _date;
00939 
00940     MakeRailDepot(tile, _current_company, d->index, dir, railtype);
00941     MarkTileDirtyByTile(tile);
00942     MakeDefaultName(d);
00943 
00944     Company::Get(_current_company)->rail_infrastructure[railtype]++;
00945     DirtyCompanyInfrastructureWindows(_current_company);
00946 
00947     AddSideToSignalBuffer(tile, INVALID_DIAGDIR, _current_company);
00948     YapfNotifyTrackLayoutChange(tile, DiagDirToDiagTrack(dir));
00949   }
00950 
00951   cost.AddCost(_price[PR_BUILD_DEPOT_TRAIN]);
00952   cost.AddCost(RailBuildCost(railtype));
00953   return cost;
00954 }
00955 
00976 CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00977 {
00978   Track track = Extract<Track, 0, 3>(p1);
00979   bool ctrl_pressed = HasBit(p1, 3); // was the CTRL button pressed
00980   SignalVariant sigvar = (ctrl_pressed ^ HasBit(p1, 4)) ? SIG_SEMAPHORE : SIG_ELECTRIC; // the signal variant of the new signal
00981   SignalType sigtype = Extract<SignalType, 5, 3>(p1); // the signal type of the new signal
00982   bool convert_signal = HasBit(p1, 8); // convert button pressed
00983   uint num_dir_cycle = GB(p1, 15, 2);
00984   uint which_signals = GB(p1, 9, 6);
00985 
00986   if (sigtype > SIGTYPE_LAST) return CMD_ERROR;
00987 
00988   /* You can only build signals on plain rail tiles or tunnel/bridges, and the selected track must exist */
00989   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
00990     if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return CMD_ERROR;
00991     CommandCost ret = EnsureNoTrainOnTrack(GetOtherTunnelBridgeEnd(tile), track);
00992     if (ret.Failed()) return ret;
00993   } else if (!ValParamTrackOrientation(track) || !IsPlainRailTile(tile) || !HasTrack(tile, track)) {
00994       return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00995   }
00996   CommandCost ret = EnsureNoTrainOnTrack(tile, track);
00997   if (ret.Failed()) return ret;
00998 
00999   /* Protect against invalid signal copying */
01000   if (p2 != 0 && (p2 & SignalOnTrack(track)) == 0) return CMD_ERROR;
01001 
01002   ret = CheckTileOwnership(tile);
01003 
01004   if (ret.Failed()) return ret;
01005 
01006   CommandCost cost;
01007   /* Handle signals simulation on tunnel/bridge. */
01008   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
01009     TileIndex tile_exit = GetOtherTunnelBridgeEnd(tile);
01010     cost = CommandCost();
01011     if (!HasWormholeSignals(tile)) { // Toggle signal zero costs.
01012       if (p2 != 12) cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] * ((GetTunnelBridgeLength(tile, tile_exit) + 4) >> 2)); // minimal 1
01013     }
01014     if (flags & DC_EXEC) {
01015       if (p2 == 0 && HasWormholeSignals(tile)){ // Toggle signal if allready signals present.
01016         if (IsTunnelBridgeEntrance (tile)) {
01017           ClrBitTunnelBridgeSignal(tile);
01018           ClrBitTunnelBridgeExit(tile_exit);
01019           SetBitTunnelBridgeExit(tile);
01020           SetBitTunnelBridgeSignal(tile_exit);
01021         } else {
01022           ClrBitTunnelBridgeSignal(tile_exit);
01023           ClrBitTunnelBridgeExit(tile);
01024           SetBitTunnelBridgeExit(tile_exit);
01025           SetBitTunnelBridgeSignal(tile);
01026         }     
01027       } else{
01028         /* Create one direction tunnel/bridge if required. */
01029         if (p2 == 0) {
01030           SetBitTunnelBridgeSignal(tile);
01031           SetBitTunnelBridgeExit(tile_exit);
01032         } else if (p2 == 4 || p2 == 8) {
01033           DiagDirection tbdir = GetTunnelBridgeDirection(tile);
01034           /* If signal only on one side build accoringly one-way tunnel/bridge. */
01035           if ((p2 == 8 && (tbdir == DIAGDIR_NE || tbdir == DIAGDIR_SE)) ||
01036             (p2 == 4 && (tbdir == DIAGDIR_SW || tbdir == DIAGDIR_NW))) {
01037             SetBitTunnelBridgeSignal(tile);
01038             SetBitTunnelBridgeExit(tile_exit);
01039           } else {
01040             SetBitTunnelBridgeSignal(tile_exit);
01041             SetBitTunnelBridgeExit(tile);
01042           }
01043         }     
01044       }
01045       MarkTileDirtyByTile(tile);
01046       MarkTileDirtyByTile(tile_exit);
01047       AddSideToSignalBuffer(tile, INVALID_DIAGDIR, _current_company);
01048       YapfNotifyTrackLayoutChange(tile, track);
01049     }
01050     return cost;
01051   }
01052 
01053   {
01054     /* See if this is a valid track combination for signals, (ie, no overlap) */
01055     TrackBits trackbits = GetTrackBits(tile);
01056     if (KillFirstBit(trackbits) != TRACK_BIT_NONE && // More than one track present
01057         trackbits != TRACK_BIT_HORZ &&
01058         trackbits != TRACK_BIT_VERT) {
01059       return_cmd_error(STR_ERROR_NO_SUITABLE_RAILROAD_TRACK);
01060     }
01061   }
01062 
01063   /* In case we don't want to change an existing signal, return without error. */
01064   if (HasBit(p1, 17) && HasSignalOnTrack(tile, track)) return CommandCost();
01065 
01066   /* you can not convert a signal if no signal is on track */
01067   if (convert_signal && !HasSignalOnTrack(tile, track)) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
01068 
01069   if (!HasSignalOnTrack(tile, track)) {
01070     /* build new signals */
01071     cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS]);
01072   } else {
01073     if (p2 != 0 && sigvar != GetSignalVariant(tile, track)) {
01074       /* convert signals <-> semaphores */
01075       cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]);
01076 
01077     } else if (convert_signal) {
01078       /* convert button pressed */
01079       if (ctrl_pressed || GetSignalVariant(tile, track) != sigvar) {
01080         /* convert electric <-> semaphore */
01081         cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]);
01082       } else {
01083         /* it is free to change signal type: normal-pre-exit-combo */
01084         cost = CommandCost();
01085       }
01086 
01087     } else {
01088       /* it is free to change orientation/pre-exit-combo signals */
01089       cost = CommandCost();
01090     }
01091   }
01092 
01093   if (flags & DC_EXEC) {
01094     Train *v = NULL;
01095     /* The new/changed signal could block our path. As this can lead to
01096      * stale reservations, we clear the path reservation here and try
01097      * to redo it later on. */
01098     if (HasReservedTracks(tile, TrackToTrackBits(track))) {
01099       v = GetTrainForReservation(tile, track);
01100       if (v != NULL) FreeTrainTrackReservation(v);
01101     }
01102 
01103     if (!HasSignals(tile)) {
01104       /* there are no signals at all on this tile yet */
01105       SetHasSignals(tile, true);
01106       SetSignalStates(tile, 0xF); // all signals are on
01107       SetPresentSignals(tile, 0); // no signals built by default
01108       SetSignalType(tile, track, sigtype);
01109       SetSignalVariant(tile, track, sigvar);
01110     }
01111 
01112     /* Subtract old signal infrastructure count. */
01113     Company::Get(GetTileOwner(tile))->signal_infrastructure -= CountBits(GetPresentSignals(tile));
01114 
01115     if (p2 == 0) {
01116       if (!HasSignalOnTrack(tile, track)) {
01117         /* build new signals */
01118         SetPresentSignals(tile, GetPresentSignals(tile) | (IsPbsSignal(sigtype) ? KillFirstBit(SignalOnTrack(track)) : SignalOnTrack(track)));
01119         SetSignalType(tile, track, sigtype);
01120         SetSignalVariant(tile, track, sigvar);
01121         while (num_dir_cycle-- > 0) CycleSignalSide(tile, track);
01122       } else {
01123         if (convert_signal) {
01124           /* convert signal button pressed */
01125           if (ctrl_pressed) {
01126             /* toggle the pressent signal variant: SIG_ELECTRIC <-> SIG_SEMAPHORE */
01127             SetSignalVariant(tile, track, (GetSignalVariant(tile, track) == SIG_ELECTRIC) ? SIG_SEMAPHORE : SIG_ELECTRIC);
01128             /* Query current signal type so the check for PBS signals below works. */
01129             sigtype = GetSignalType(tile, track);
01130           } else {
01131             /* convert the present signal to the chosen type and variant */
01132             if (IsPresignalProgrammable(tile, track)) {
01133               FreeSignalProgram(SignalReference(tile, track));
01134             } else if(IsSpeedSignal(tile, track)) {
01135               FreeSignalSpeed(SignalReference(tile, track));
01136             }
01137             SetSignalType(tile, track, sigtype);
01138             SetSignalVariant(tile, track, sigvar);
01139             if (IsPbsSignal(sigtype) && (GetPresentSignals(tile) & SignalOnTrack(track)) == SignalOnTrack(track)) {
01140               SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | KillFirstBit(SignalOnTrack(track)));
01141             }
01142           }
01143 
01144         } else if (ctrl_pressed) {
01145           /* cycle through signal types */
01146           sigtype = (SignalType)(GetSignalType(tile, track));
01147           if(IsProgrammableSignal(sigtype)) {
01148             FreeSignalProgram(SignalReference(tile, track));
01149           } else if(IsSpeedSignal(sigtype)) {
01150             FreeSignalSpeed(SignalReference(tile, track));
01151           }
01152           sigtype = NextSignalType(sigtype, which_signals);
01153           SetSignalType(tile, track, sigtype);
01154           if (IsPbsSignal(sigtype) && (GetPresentSignals(tile) & SignalOnTrack(track)) == SignalOnTrack(track)) {
01155             SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | KillFirstBit(SignalOnTrack(track)));
01156           }
01157         } else {
01158           /* cycle the signal side: both -> left -> right -> both -> ... */
01159           CycleSignalSide(tile, track);
01160           /* Query current signal type so the check for PBS signals below works. */
01161           sigtype = GetSignalType(tile, track);
01162         }
01163       }
01164     } else {
01165       /* If CmdBuildManySignals is called with copying signals, just copy the
01166        * direction of the first signal given as parameter by CmdBuildManySignals */
01167       SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | (p2 & SignalOnTrack(track)));
01168       SetSignalVariant(tile, track, sigvar);
01169       if(IsPresignalProgrammable(tile, track)) {
01170         FreeSignalProgram(SignalReference(tile, track));
01171       } else if(IsSpeedSignal(tile, track)) {
01172         FreeSignalSpeed(SignalReference(tile, track));
01173       }
01174       SetSignalType(tile, track, sigtype);
01175     }
01176 
01177     /* Add new signal infrastructure count. */
01178     Company::Get(GetTileOwner(tile))->signal_infrastructure += CountBits(GetPresentSignals(tile));
01179     DirtyCompanyInfrastructureWindows(GetTileOwner(tile));
01180 
01181     if (IsPbsSignal(sigtype)) {
01182       /* PBS signals should show red unless they are on a reservation. */
01183       uint mask = GetPresentSignals(tile) & SignalOnTrack(track);
01184       SetSignalStates(tile, (GetSignalStates(tile) & ~mask) | ((HasBit(GetRailReservationTrackBits(tile), track) ? UINT_MAX : 0) & mask));
01185     }
01186     MarkTileDirtyByTile(tile);
01187     AddTrackToSignalBuffer(tile, track, _current_company);
01188     YapfNotifyTrackLayoutChange(tile, track);
01189     if (v != NULL) {
01190       /* Extend the train's path if it's not stopped or loading, or not at a safe position. */
01191       if (!(((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) || v->current_order.IsType(OT_LOADING)) ||
01192           !IsSafeWaitingPosition(v, v->tile, v->GetVehicleTrackdir(), true, _settings_game.pf.forbid_90_deg)) {
01193         TryPathReserve(v, true);
01194       }
01195     }
01196   }
01197 
01198   return cost;
01199 }
01200 
01201 static bool CheckSignalAutoFill(TileIndex &tile, Trackdir &trackdir, int &signal_ctr, bool remove)
01202 {
01203   tile = AddTileIndexDiffCWrap(tile, _trackdelta[trackdir]);
01204   if (tile == INVALID_TILE) return false;
01205 
01206   /* Check for track bits on the new tile */
01207   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0));
01208 
01209   if (TracksOverlap(TrackdirBitsToTrackBits(trackdirbits))) return false;
01210   trackdirbits &= TrackdirReachesTrackdirs(trackdir);
01211 
01212   /* No track bits, must stop */
01213   if (trackdirbits == TRACKDIR_BIT_NONE) return false;
01214 
01215   /* Get the first track dir */
01216   trackdir = RemoveFirstTrackdir(&trackdirbits);
01217 
01218   /* Any left? It's a junction so we stop */
01219   if (trackdirbits != TRACKDIR_BIT_NONE) return false;
01220 
01221   switch (GetTileType(tile)) {
01222     case MP_RAILWAY:
01223       if (IsRailDepot(tile)) return false;
01224       if (!remove && HasSignalOnTrack(tile, TrackdirToTrack(trackdir))) return false;
01225       signal_ctr++;
01226       if (IsDiagonalTrackdir(trackdir)) {
01227         signal_ctr++;
01228         /* Ensure signal_ctr even so X and Y pieces get signals */
01229         ClrBit(signal_ctr, 0);
01230       }
01231       return true;
01232 
01233     case MP_ROAD:
01234       if (!IsLevelCrossing(tile)) return false;
01235       signal_ctr += 2;
01236       return true;
01237 
01238     case MP_TUNNELBRIDGE: {
01239       if (!remove && HasWormholeSignals(tile)) return false;
01240       TileIndex orig_tile = tile; // backup old value
01241 
01242       if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return false;
01243       if (GetTunnelBridgeDirection(tile) != TrackdirToExitdir(trackdir)) return false;
01244 
01245       /* Skip to end of tunnel or bridge
01246        * note that tile is a parameter by reference, so it must be updated */
01247       tile = GetOtherTunnelBridgeEnd(tile);
01248 
01249       signal_ctr += (GetTunnelBridgeLength(orig_tile, tile) + 2) * 2;
01250       return true;
01251     }
01252 
01253     default: return false;
01254   }
01255 }
01256 
01273 static CommandCost CmdSignalTrackHelper(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01274 {
01275   CommandCost total_cost(EXPENSES_CONSTRUCTION);
01276   TileIndex start_tile = tile;
01277 
01278   Track track = Extract<Track, 0, 3>(p2);
01279   bool mode = HasBit(p2, 3);
01280   bool semaphores = HasBit(p2, 4);
01281   bool remove = HasBit(p2, 5);
01282   bool autofill = HasBit(p2, 6);
01283   byte signal_density = GB(p2, 24, 8);
01284 
01285   if (p1 >= MapSize() || !ValParamTrackOrientation(track)) return CMD_ERROR;
01286   TileIndex end_tile = p1;
01287   if (signal_density == 0 || signal_density > 20) return CMD_ERROR;
01288 
01289   if (!IsPlainRailTile(tile)) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
01290 
01291   /* for vertical/horizontal tracks, double the given signals density
01292    * since the original amount will be too dense (shorter tracks) */
01293   signal_density *= 2;
01294 
01295   Trackdir trackdir = TrackToTrackdir(track);
01296   CommandCost ret = ValidateAutoDrag(&trackdir, tile, end_tile);
01297   if (ret.Failed()) return ret;
01298 
01299   track = TrackdirToTrack(trackdir); // trackdir might have changed, keep track in sync
01300   Trackdir start_trackdir = trackdir;
01301 
01302   /* Must start on a valid track to be able to avoid loops */
01303   if (!HasTrack(tile, track)) return CMD_ERROR;
01304 
01305   SignalType sigtype = (SignalType)GB(p2, 7, 3);
01306   if (sigtype > SIGTYPE_LAST) return CMD_ERROR;
01307 
01308   byte signals;
01309   /* copy the signal-style of the first rail-piece if existing */
01310   if (HasSignalOnTrack(tile, track)) {
01311     signals = GetPresentSignals(tile) & SignalOnTrack(track);
01312     assert(signals != 0);
01313 
01314     /* copy signal/semaphores style (independent of CTRL) */
01315     semaphores = GetSignalVariant(tile, track) != SIG_ELECTRIC;
01316 
01317     sigtype = GetSignalType(tile, track);
01318     /* Don't but copy entry or exit-signal type */
01319     if (sigtype == SIGTYPE_ENTRY || sigtype == SIGTYPE_EXIT) sigtype = SIGTYPE_NORMAL;
01320   } else { // no signals exist, drag a two-way signal stretch
01321     signals = IsPbsSignal(sigtype) ? SignalAlongTrackdir(trackdir) : SignalOnTrack(track);
01322   }
01323 
01324   byte signal_dir = 0;
01325   if (signals & SignalAlongTrackdir(trackdir))   SetBit(signal_dir, 0);
01326   if (signals & SignalAgainstTrackdir(trackdir)) SetBit(signal_dir, 1);
01327 
01328   /* signal_ctr         - amount of tiles already processed
01329    * signals_density    - setting to put signal on every Nth tile (double space on |, -- tracks)
01330    **********
01331    * trackdir   - trackdir to build with autorail
01332    * semaphores - semaphores or signals
01333    * signals    - is there a signal/semaphore on the first tile, copy its style (two-way/single-way)
01334    *              and convert all others to semaphore/signal
01335    * remove     - 1 remove signals, 0 build signals */
01336   int signal_ctr = 0;
01337   CommandCost last_error = CMD_ERROR;
01338   bool had_success = false;
01339   for (;;) {
01340     /* only build/remove signals with the specified density */
01341     if ((remove && autofill) || signal_ctr % signal_density == 0 || IsTileType(tile, MP_TUNNELBRIDGE)) {
01342       uint32 p1 = GB(TrackdirToTrack(trackdir), 0, 3);
01343       SB(p1, 3, 1, mode);
01344       SB(p1, 4, 1, semaphores);
01345       SB(p1, 5, 3, sigtype);
01346       if (!remove && signal_ctr == 0) SetBit(p1, 17);
01347 
01348       /* Pick the correct orientation for the track direction */
01349       signals = 0;
01350       if (HasBit(signal_dir, 0)) signals |= SignalAlongTrackdir(trackdir);
01351       if (HasBit(signal_dir, 1)) signals |= SignalAgainstTrackdir(trackdir);
01352 
01353       CommandCost ret = DoCommand(tile, p1, signals, flags, remove ? CMD_REMOVE_SIGNALS : CMD_BUILD_SIGNALS);
01354 
01355       /* Be user-friendly and try placing signals as much as possible */
01356       if (ret.Succeeded()) {
01357         had_success = true;
01358         if (IsTileType(tile, MP_TUNNELBRIDGE)) {
01359           if ((!autofill && GetTunnelBridgeDirection(tile) == TrackdirToExitdir(trackdir)) ||
01360               (autofill && GetTunnelBridgeDirection(tile) != TrackdirToExitdir(trackdir))) {
01361             total_cost.AddCost(ret);
01362           }
01363         } else {
01364           total_cost.AddCost(ret);
01365         }
01366       } else {
01367         /* The "No railway" error is the least important one. */
01368         if (ret.GetErrorMessage() != STR_ERROR_THERE_IS_NO_RAILROAD_TRACK ||
01369             last_error.GetErrorMessage() == INVALID_STRING_ID) {
01370           last_error = ret;
01371         }
01372       }
01373     }
01374 
01375     if (autofill) {
01376       if (!CheckSignalAutoFill(tile, trackdir, signal_ctr, remove)) break;
01377 
01378       /* Prevent possible loops */
01379       if (tile == start_tile && trackdir == start_trackdir) break;
01380     } else {
01381       if (tile == end_tile) break;
01382 
01383       tile += ToTileIndexDiff(_trackdelta[trackdir]);
01384       signal_ctr++;
01385 
01386       /* toggle railbit for the non-diagonal tracks (|, -- tracks) */
01387       if (IsDiagonalTrackdir(trackdir)) {
01388         signal_ctr++;
01389       } else {
01390         ToggleBit(trackdir, 0);
01391       }
01392     }
01393   }
01394 
01395   return had_success ? total_cost : last_error;
01396 }
01397 
01416 CommandCost CmdBuildSignalTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01417 {
01418   return CmdSignalTrackHelper(tile, flags, p1, p2, text);
01419 }
01420 
01433 CommandCost CmdRemoveSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01434 {
01435   Track track = Extract<Track, 0, 3>(p1);
01436   Money cost = _price[PR_CLEAR_SIGNALS];
01437 
01438   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
01439     TileIndex end = GetOtherTunnelBridgeEnd(tile);
01440     if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
01441     if (!HasWormholeSignals(tile)) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
01442 
01443     cost *= ((GetTunnelBridgeLength(tile, end) + 4) >> 2);
01444 
01445     CommandCost ret = EnsureNoTrainOnTrack(GetOtherTunnelBridgeEnd(tile), track);
01446     if (ret.Failed()) return ret;
01447   } else {
01448     if (!ValParamTrackOrientation(track) || !IsPlainRailTile(tile) || !HasTrack(tile, track)) {
01449       return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
01450     }
01451     if (!HasSignalOnTrack(tile, track)) {
01452       return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
01453     }
01454     CommandCost ret = EnsureNoTrainOnTrack(tile, track);
01455     if (ret.Failed()) return ret;
01456   }
01457 
01458   /* Only water can remove signals from anyone */
01459   if (_current_company != OWNER_WATER) {
01460     CommandCost ret = CheckTileOwnership(tile);
01461     if (ret.Failed()) return ret;
01462   }
01463 
01464   /* Do it? */
01465   if (flags & DC_EXEC) {
01466 
01467     if (HasWormholeSignals(tile)) { // Handle tunnel/bridge signals.
01468       TileIndex end = GetOtherTunnelBridgeEnd(tile);
01469       ClrBitTunnelBridgeExit(tile);
01470       ClrBitTunnelBridgeExit(end);
01471       ClrBitTunnelBridgeSignal(tile);
01472       ClrBitTunnelBridgeSignal(end);
01473       _m[tile].m2 = 0;
01474       _m[end].m2 = 0;
01475       MarkTileDirtyByTile(tile);
01476       MarkTileDirtyByTile(end);
01477       return CommandCost(EXPENSES_CONSTRUCTION, cost);
01478     }
01479 
01480     Train *v = NULL;
01481     if (HasReservedTracks(tile, TrackToTrackBits(track))) {
01482       v = GetTrainForReservation(tile, track);
01483     } else if (IsPbsSignal(GetSignalType(tile, track))) {
01484       /* PBS signal, might be the end of a path reservation. */
01485       Trackdir td = TrackToTrackdir(track);
01486       for (int i = 0; v == NULL && i < 2; i++, td = ReverseTrackdir(td)) {
01487         /* Only test the active signal side. */
01488         if (!HasSignalOnTrackdir(tile, ReverseTrackdir(td))) continue;
01489         TileIndex next = TileAddByDiagDir(tile, TrackdirToExitdir(td));
01490         TrackBits tracks = TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(td));
01491         if (HasReservedTracks(next, tracks)) {
01492           v = GetTrainForReservation(next, TrackBitsToTrack(GetReservedTrackbits(next) & tracks));
01493         }
01494       }
01495     }
01496     
01497     CheckRemoveSignal(tile, track);
01498     Company::Get(GetTileOwner(tile))->signal_infrastructure -= CountBits(GetPresentSignals(tile));
01499     SetPresentSignals(tile, GetPresentSignals(tile) & ~SignalOnTrack(track));
01500     Company::Get(GetTileOwner(tile))->signal_infrastructure += CountBits(GetPresentSignals(tile));
01501     DirtyCompanyInfrastructureWindows(GetTileOwner(tile));
01502 
01503     /* removed last signal from tile? */
01504     if (GetPresentSignals(tile) == 0) {
01505       SetSignalStates(tile, 0);
01506       SetHasSignals(tile, false);
01507       SetSignalVariant(tile, INVALID_TRACK, SIG_ELECTRIC); // remove any possible semaphores
01508     }
01509 
01510     AddTrackToSignalBuffer(tile, track, GetTileOwner(tile));
01511     YapfNotifyTrackLayoutChange(tile, track);
01512     if (v != NULL) TryPathReserve(v, false);
01513 
01514     MarkTileDirtyByTile(tile);
01515   }
01516 
01517   return CommandCost(EXPENSES_CONSTRUCTION, cost);
01518 }
01519 
01538 CommandCost CmdRemoveSignalTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01539 {
01540   return CmdSignalTrackHelper(tile, flags, p1, SetBit(p2, 5), text); // bit 5 is remove bit
01541 }
01542 
01544 static Vehicle *UpdateTrainPowerProc(Vehicle *v, void *data)
01545 {
01546   if (v->type != VEH_TRAIN) return NULL;
01547 
01548   TrainList *affected_trains = static_cast<TrainList*>(data);
01549   affected_trains->Include(Train::From(v)->First());
01550 
01551   return NULL;
01552 }
01553 
01564 CommandCost CmdConvertRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01565 {
01566   RailType totype = Extract<RailType, 0, 4>(p2);
01567 
01568   if (!ValParamRailtype(totype)) return CMD_ERROR;
01569   if (p1 >= MapSize()) return CMD_ERROR;
01570 
01571   TrainList affected_trains;
01572 
01573   CommandCost cost(EXPENSES_CONSTRUCTION);
01574   CommandCost error = CommandCost(STR_ERROR_NO_SUITABLE_RAILROAD_TRACK); // by default, there is no track to convert.
01575   TileArea ta(tile, p1);
01576   TILE_AREA_LOOP(tile, ta) {
01577     TileType tt = GetTileType(tile);
01578 
01579     /* Check if there is any track on tile */
01580     switch (tt) {
01581       case MP_RAILWAY:
01582         break;
01583       case MP_STATION:
01584         if (!HasStationRail(tile)) continue;
01585         break;
01586       case MP_ROAD:
01587         if (!IsLevelCrossing(tile)) continue;
01588         if (RailNoLevelCrossings(totype)) {
01589           error.MakeError(STR_ERROR_CROSSING_DISALLOWED);
01590           continue;
01591         }
01592         break;
01593       case MP_TUNNELBRIDGE:
01594         if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) continue;
01595         break;
01596       default: continue;
01597     }
01598 
01599     /* Original railtype we are converting from */
01600     RailType type = GetRailType(tile);
01601 
01602     /* Converting to the same type or converting 'hidden' elrail -> rail */
01603     if (type == totype || (_settings_game.vehicle.disable_elrails && totype == RAILTYPE_RAIL && type == RAILTYPE_ELECTRIC)) continue;
01604 
01605     /* Trying to convert other's rail */
01606     CommandCost ret = CheckTileOwnership(tile);
01607     if (ret.Failed()) {
01608       error = ret;
01609       continue;
01610     }
01611 
01612     SmallVector<Train *, 2> vehicles_affected;
01613 
01614     /* Vehicle on the tile when not converting Rail <-> ElRail
01615      * Tunnels and bridges have special check later */
01616     if (tt != MP_TUNNELBRIDGE) {
01617       if (!IsCompatibleRail(type, totype)) {
01618         CommandCost ret = EnsureNoVehicleOnGround(tile);
01619         if (ret.Failed()) {
01620           error = ret;
01621           continue;
01622         }
01623       }
01624       if (flags & DC_EXEC) { // we can safely convert, too
01625         TrackBits reserved = GetReservedTrackbits(tile);
01626         Track     track;
01627         while ((track = RemoveFirstTrack(&reserved)) != INVALID_TRACK) {
01628           Train *v = GetTrainForReservation(tile, track);
01629           if (v != NULL && !HasPowerOnRail(v->railtype, totype)) {
01630             /* No power on new rail type, reroute. */
01631             FreeTrainTrackReservation(v);
01632             *vehicles_affected.Append() = v;
01633           }
01634         }
01635 
01636         /* Update the company infrastructure counters. */
01637         if (!IsRailStationTile(tile) || !IsStationTileBlocked(tile)) {
01638           Company *c = Company::Get(GetTileOwner(tile));
01639           uint num_pieces = IsLevelCrossingTile(tile) ? LEVELCROSSING_TRACKBIT_FACTOR : 1;
01640           if (IsPlainRailTile(tile)) {
01641             TrackBits bits = GetTrackBits(tile);
01642             num_pieces = CountBits(bits);
01643             if (TracksOverlap(bits)) num_pieces *= num_pieces;
01644           }
01645           c->rail_infrastructure[type] -= num_pieces;
01646           c->rail_infrastructure[totype] += num_pieces;
01647           DirtyCompanyInfrastructureWindows(c->index);
01648         }
01649 
01650         SetRailType(tile, totype);
01651         MarkTileDirtyByTile(tile);
01652         /* update power of train on this tile */
01653         FindVehicleOnPos(tile, &affected_trains, &UpdateTrainPowerProc);
01654       }
01655     }
01656 
01657     switch (tt) {
01658       case MP_RAILWAY:
01659         switch (GetRailTileType(tile)) {
01660           case RAIL_TILE_DEPOT:
01661             if (flags & DC_EXEC) {
01662               /* notify YAPF about the track layout change */
01663               YapfNotifyTrackLayoutChange(tile, GetRailDepotTrack(tile));
01664 
01665               /* Update build vehicle window related to this depot */
01666               InvalidateWindowData(WC_VEHICLE_DEPOT, tile);
01667               InvalidateWindowData(WC_BUILD_VEHICLE, tile);
01668             }
01669             cost.AddCost(RailConvertCost(type, totype));
01670             break;
01671 
01672           default: // RAIL_TILE_NORMAL, RAIL_TILE_SIGNALS
01673             if (flags & DC_EXEC) {
01674               /* notify YAPF about the track layout change */
01675               TrackBits tracks = GetTrackBits(tile);
01676               while (tracks != TRACK_BIT_NONE) {
01677                 YapfNotifyTrackLayoutChange(tile, RemoveFirstTrack(&tracks));
01678               }
01679             }
01680             cost.AddCost(RailConvertCost(type, totype) * CountBits(GetTrackBits(tile)));
01681             break;
01682         }
01683         break;
01684 
01685       case MP_TUNNELBRIDGE: {
01686         TileIndex endtile = GetOtherTunnelBridgeEnd(tile);
01687 
01688         /* If both ends of tunnel/bridge are in the range, do not try to convert twice -
01689          * it would cause assert because of different test and exec runs */
01690         if (endtile < tile && TileX(endtile) >= TileX(ta.tile) && TileX(endtile) < TileX(ta.tile) + ta.w &&
01691             TileY(endtile) >= TileY(ta.tile) && TileY(endtile) < TileY(ta.tile) + ta.h) continue;
01692 
01693         /* When not coverting rail <-> el. rail, any vehicle cannot be in tunnel/bridge */
01694         if (!IsCompatibleRail(GetRailType(tile), totype)) {
01695           CommandCost ret = TunnelBridgeIsFree(tile, endtile);
01696           if (ret.Failed()) {
01697             error = ret;
01698             continue;
01699           }
01700         }
01701 
01702         if (flags & DC_EXEC) {
01703           Track track = DiagDirToDiagTrack(GetTunnelBridgeDirection(tile));
01704           if (HasTunnelBridgeReservation(tile)) {
01705             Train *v = GetTrainForReservation(tile, track);
01706             if (v != NULL && !HasPowerOnRail(v->railtype, totype)) {
01707               /* No power on new rail type, reroute. */
01708               FreeTrainTrackReservation(v);
01709               *vehicles_affected.Append() = v;
01710             }
01711           }
01712 
01713           /* Update the company infrastructure counters. */
01714           uint num_pieces = (GetTunnelBridgeLength(tile, endtile) + 2) * TUNNELBRIDGE_TRACKBIT_FACTOR;
01715           Company *c = Company::Get(GetTileOwner(tile));
01716           c->rail_infrastructure[GetRailType(tile)] -= num_pieces;
01717           c->rail_infrastructure[totype] += num_pieces;
01718           DirtyCompanyInfrastructureWindows(c->index);
01719 
01720           SetRailType(tile, totype);
01721           SetRailType(endtile, totype);
01722 
01723           FindVehicleOnPos(tile, &affected_trains, &UpdateTrainPowerProc);
01724           FindVehicleOnPos(endtile, &affected_trains, &UpdateTrainPowerProc);
01725 
01726           YapfNotifyTrackLayoutChange(tile, track);
01727           YapfNotifyTrackLayoutChange(endtile, track);
01728 
01729           MarkTileDirtyByTile(tile);
01730           MarkTileDirtyByTile(endtile);
01731 
01732           if (IsBridge(tile)) {
01733             TileIndexDiff delta = TileOffsByDiagDir(GetTunnelBridgeDirection(tile));
01734             TileIndex t = tile + delta;
01735             for (; t != endtile; t += delta) MarkTileDirtyByTile(t); // TODO encapsulate this into a function
01736           }
01737         }
01738 
01739         cost.AddCost((GetTunnelBridgeLength(tile, endtile) + 2) * RailConvertCost(type, totype));
01740         break;
01741       }
01742 
01743       default: // MP_STATION, MP_ROAD
01744         if (flags & DC_EXEC) {
01745           Track track = ((tt == MP_STATION) ? GetRailStationTrack(tile) : GetCrossingRailTrack(tile));
01746           YapfNotifyTrackLayoutChange(tile, track);
01747         }
01748 
01749         cost.AddCost(RailConvertCost(type, totype));
01750         break;
01751     }
01752 
01753     for (uint i = 0; i < vehicles_affected.Length(); ++i) {
01754       TryPathReserve(vehicles_affected[i], true);
01755     }
01756   }
01757 
01758   if (flags & DC_EXEC) {
01759     /* Railtype changed, update trains as when entering different track */
01760     for (Train **v = affected_trains.Begin(); v != affected_trains.End(); v++) {
01761       (*v)->RailtypeChanged();
01762     }
01763   }
01764 
01765   return (cost.GetCost() == 0) ? error : cost;
01766 }
01767 
01768 static CommandCost RemoveTrainDepot(TileIndex tile, DoCommandFlag flags)
01769 {
01770   if (_current_company != OWNER_WATER) {
01771     CommandCost ret = CheckTileOwnership(tile);
01772     if (ret.Failed()) return ret;
01773   }
01774 
01775   CommandCost ret = EnsureNoVehicleOnGround(tile);
01776   if (ret.Failed()) return ret;
01777 
01778   if (flags & DC_EXEC) {
01779     /* read variables before the depot is removed */
01780     DiagDirection dir = GetRailDepotDirection(tile);
01781     Owner owner = GetTileOwner(tile);
01782     Train *v = NULL;
01783 
01784     if (HasDepotReservation(tile)) {
01785       v = GetTrainForReservation(tile, DiagDirToDiagTrack(dir));
01786       if (v != NULL) FreeTrainTrackReservation(v);
01787     }
01788 
01789     Company::Get(owner)->rail_infrastructure[GetRailType(tile)]--;
01790     DirtyCompanyInfrastructureWindows(owner);
01791 
01792     delete Depot::GetByTile(tile);
01793     DoClearSquare(tile);
01794     AddSideToSignalBuffer(tile, dir, owner);
01795     YapfNotifyTrackLayoutChange(tile, DiagDirToDiagTrack(dir));
01796     if (v != NULL) TryPathReserve(v, true);
01797   }
01798 
01799   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_DEPOT_TRAIN]);
01800 }
01801 
01802 static CommandCost ClearTile_Track(TileIndex tile, DoCommandFlag flags)
01803 {
01804   CommandCost cost(EXPENSES_CONSTRUCTION);
01805 
01806   if (flags & DC_AUTO) {
01807     if (!IsTileOwner(tile, _current_company)) {
01808       return_cmd_error(STR_ERROR_AREA_IS_OWNED_BY_ANOTHER);
01809     }
01810 
01811     if (IsPlainRail(tile)) {
01812       return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
01813     } else {
01814       return_cmd_error(STR_ERROR_BUILDING_MUST_BE_DEMOLISHED);
01815     }
01816   }
01817 
01818   switch (GetRailTileType(tile)) {
01819     case RAIL_TILE_SIGNALS:
01820       if (flags & DC_EXEC) CheckRemoveSignalsFromTile(tile);
01821 
01822     case RAIL_TILE_NORMAL: {
01823       Slope tileh = GetTileSlope(tile, NULL);
01824       /* Is there flat water on the lower halftile that gets cleared expensively? */
01825       bool water_ground = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh));
01826 
01827       TrackBits tracks = GetTrackBits(tile);
01828       while (tracks != TRACK_BIT_NONE) {
01829         Track track = RemoveFirstTrack(&tracks);
01830         CommandCost ret = DoCommand(tile, 0, track, flags, CMD_REMOVE_SINGLE_RAIL);
01831         if (ret.Failed()) return ret;
01832         cost.AddCost(ret);
01833       }
01834 
01835       /* when bankrupting, don't make water dirty, there could be a ship on lower halftile */
01836       if (water_ground && !(flags & DC_BANKRUPT)) {
01837         CommandCost ret = EnsureNoVehicleOnGround(tile);
01838         if (ret.Failed()) return ret;
01839 
01840         /* The track was removed, and left a coast tile. Now also clear the water. */
01841         if (flags & DC_EXEC) DoClearSquare(tile);
01842         cost.AddCost(_price[PR_CLEAR_WATER]);
01843       }
01844 
01845       return cost;
01846     }
01847 
01848     case RAIL_TILE_DEPOT:
01849       return RemoveTrainDepot(tile, flags);
01850 
01851     default:
01852       return CMD_ERROR;
01853   }
01854 }
01855 
01860 static uint GetSaveSlopeZ(uint x, uint y, Track track)
01861 {
01862   switch (track) {
01863     case TRACK_UPPER: x &= ~0xF; y &= ~0xF; break;
01864     case TRACK_LOWER: x |=  0xF; y |=  0xF; break;
01865     case TRACK_LEFT:  x |=  0xF; y &= ~0xF; break;
01866     case TRACK_RIGHT: x &= ~0xF; y |=  0xF; break;
01867     default: break;
01868   }
01869   return GetSlopeZ(x, y);
01870 }
01871 
01872 static void DrawSingleSignal(TileIndex tile, Track track, byte condition, uint image, uint pos)
01873 {
01874   bool side = (_settings_game.vehicle.road_side != 0) && _settings_game.construction.signal_side;
01875   static const Point SignalPositions[2][12] = {
01876     { // Signals on the left side
01877     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01878       { 8,  5}, {14,  1}, { 1, 14}, { 9, 11}, { 1,  0}, { 3, 10},
01879     /*  LOWER     LOWER     X         X         Y         Y     */
01880       {11,  4}, {14, 14}, {11,  3}, { 4, 13}, { 3,  4}, {11, 13}
01881     }, { // Signals on the right side
01882     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01883       {14,  1}, {12, 10}, { 4,  6}, { 1, 14}, {10,  4}, { 0,  1},
01884     /*  LOWER     LOWER     X         X         Y         Y     */
01885       {14, 14}, { 5, 12}, {11, 13}, { 4,  3}, {13,  4}, { 3, 11}
01886     }
01887   };
01888 
01889   uint x = TileX(tile) * TILE_SIZE + SignalPositions[side][pos].x;
01890   uint y = TileY(tile) * TILE_SIZE + SignalPositions[side][pos].y;
01891 
01892   SpriteID sprite;
01893 
01894   SignalType type       = GetSignalType(tile, track);
01895   SignalVariant variant = GetSignalVariant(tile, track);
01896 
01897   if (type == SIGTYPE_NORMAL && variant == SIG_ELECTRIC) {
01898     /* Normal electric signals are picked from original sprites. */
01899     sprite = SPR_ORIGINAL_SIGNALS_BASE + image + condition;
01900 // TODO: change drawing of speed and progsigs to the "other signals" method when the sprites are added to openttd.grf.
01901   } else if (type == SIGTYPE_PROG && variant == SIG_ELECTRIC) {
01902     /* Speed electric signals are picked from speedsignals.gf sprites. */
01903     sprite = (SPR_PROGSIGNAL_BASE + 16) + image + condition;
01904   } else if (type == SIGTYPE_PROG && variant == SIG_SEMAPHORE) {
01905     /* Speed semaphore signals are picked from speedsignals.gf sprites. */
01906     sprite = SPR_PROGSIGNAL_BASE + image + condition;
01907   } else if (type == SIGTYPE_SPEED && variant == SIG_ELECTRIC) {
01908     /* Speed electric signals are picked from speedsignals.gf sprites. */
01909     sprite = (SPR_SPEEDSIGNAL_BASE + 16) + image + condition;
01910   } else if (type == SIGTYPE_SPEED && variant == SIG_SEMAPHORE) {
01911     /* Speed semaphore signals are picked from speedsignals.gf sprites. */
01912     sprite = SPR_SPEEDSIGNAL_BASE + image + condition;
01913   } else {
01914     /* All other signals are picked from add on sprites. */
01915     sprite = SPR_SIGNALS_BASE + (type - 1) * 16 + variant * 64 + image + condition + (IsSignalSpritePBS(type) ? 64 : 0);
01916   }
01917 
01918   AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
01919 }
01920 
01921 static uint32 _drawtile_track_palette;
01922 
01923 
01924 static void DrawTrackFence_NW(const TileInfo *ti, SpriteID base_image)
01925 {
01926   RailFenceOffset rfo = RFO_FLAT_X;
01927   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SW : RFO_SLOPE_NE;
01928   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01929     ti->x, ti->y + 1, 16, 1, 4, ti->z);
01930 }
01931 
01932 static void DrawTrackFence_SE(const TileInfo *ti, SpriteID base_image)
01933 {
01934   RailFenceOffset rfo = RFO_FLAT_X;
01935   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SW : RFO_SLOPE_NE;
01936   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01937     ti->x, ti->y + TILE_SIZE - 1, 16, 1, 4, ti->z);
01938 }
01939 
01940 static void DrawTrackFence_NW_SE(const TileInfo *ti, SpriteID base_image)
01941 {
01942   DrawTrackFence_NW(ti, base_image);
01943   DrawTrackFence_SE(ti, base_image);
01944 }
01945 
01946 static void DrawTrackFence_NE(const TileInfo *ti, SpriteID base_image)
01947 {
01948   RailFenceOffset rfo = RFO_FLAT_Y;
01949   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SE : RFO_SLOPE_NW;
01950   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01951     ti->x + 1, ti->y, 1, 16, 4, ti->z);
01952 }
01953 
01954 static void DrawTrackFence_SW(const TileInfo *ti, SpriteID base_image)
01955 {
01956   RailFenceOffset rfo = RFO_FLAT_Y;
01957   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SE : RFO_SLOPE_NW;
01958   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01959     ti->x + TILE_SIZE - 1, ti->y, 1, 16, 4, ti->z);
01960 }
01961 
01962 static void DrawTrackFence_NE_SW(const TileInfo *ti, SpriteID base_image)
01963 {
01964   DrawTrackFence_NE(ti, base_image);
01965   DrawTrackFence_SW(ti, base_image);
01966 }
01967 
01971 static void DrawTrackFence_NS_1(const TileInfo *ti, SpriteID base_image)
01972 {
01973   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_W);
01974   AddSortableSpriteToDraw(base_image + RFO_FLAT_VERT, _drawtile_track_palette,
01975     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01976 }
01977 
01981 static void DrawTrackFence_NS_2(const TileInfo *ti, SpriteID base_image)
01982 {
01983   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_E);
01984   AddSortableSpriteToDraw(base_image + RFO_FLAT_VERT, _drawtile_track_palette,
01985     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01986 }
01987 
01991 static void DrawTrackFence_WE_1(const TileInfo *ti, SpriteID base_image)
01992 {
01993   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_N);
01994   AddSortableSpriteToDraw(base_image + RFO_FLAT_HORZ, _drawtile_track_palette,
01995     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01996 }
01997 
02001 static void DrawTrackFence_WE_2(const TileInfo *ti, SpriteID base_image)
02002 {
02003   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_S);
02004   AddSortableSpriteToDraw(base_image + RFO_FLAT_HORZ, _drawtile_track_palette,
02005     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
02006 }
02007 
02008 
02009 static void DrawTrackDetails(const TileInfo *ti, const RailtypeInfo *rti)
02010 {
02011   /* Base sprite for track fences.
02012    * Note: Halftile slopes only have fences on the upper part. */
02013   SpriteID base_image = GetCustomRailSprite(rti, ti->tile, RTSG_FENCES, IsHalftileSlope(ti->tileh) ? TCX_UPPER_HALFTILE : TCX_NORMAL);
02014   if (base_image == 0) base_image = SPR_TRACK_FENCE_FLAT_X;
02015 
02016   switch (GetRailGroundType(ti->tile)) {
02017     case RAIL_GROUND_FENCE_NW:     DrawTrackFence_NW(ti, base_image);    break;
02018     case RAIL_GROUND_FENCE_SE:     DrawTrackFence_SE(ti, base_image);    break;
02019     case RAIL_GROUND_FENCE_SENW:   DrawTrackFence_NW_SE(ti, base_image); break;
02020     case RAIL_GROUND_FENCE_NE:     DrawTrackFence_NE(ti, base_image);    break;
02021     case RAIL_GROUND_FENCE_SW:     DrawTrackFence_SW(ti, base_image);    break;
02022     case RAIL_GROUND_FENCE_NESW:   DrawTrackFence_NE_SW(ti, base_image); break;
02023     case RAIL_GROUND_FENCE_VERT1:  DrawTrackFence_NS_1(ti, base_image);  break;
02024     case RAIL_GROUND_FENCE_VERT2:  DrawTrackFence_NS_2(ti, base_image);  break;
02025     case RAIL_GROUND_FENCE_HORIZ1: DrawTrackFence_WE_1(ti, base_image);  break;
02026     case RAIL_GROUND_FENCE_HORIZ2: DrawTrackFence_WE_2(ti, base_image);  break;
02027     case RAIL_GROUND_WATER: {
02028       Corner track_corner;
02029       if (IsHalftileSlope(ti->tileh)) {
02030         /* Steep slope or one-corner-raised slope with halftile foundation */
02031         track_corner = GetHalftileSlopeCorner(ti->tileh);
02032       } else {
02033         /* Three-corner-raised slope */
02034         track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
02035       }
02036       switch (track_corner) {
02037         case CORNER_W: DrawTrackFence_NS_1(ti, base_image); break;
02038         case CORNER_S: DrawTrackFence_WE_2(ti, base_image); break;
02039         case CORNER_E: DrawTrackFence_NS_2(ti, base_image); break;
02040         case CORNER_N: DrawTrackFence_WE_1(ti, base_image); break;
02041         default: NOT_REACHED();
02042       }
02043       break;
02044     }
02045     default: break;
02046   }
02047 }
02048 
02049 /* SubSprite for drawing the track halftile of 'three-corners-raised'-sloped rail sprites. */
02050 static const int INF = 1000; // big number compared to tilesprite size
02051 static const SubSprite _halftile_sub_sprite[4] = {
02052   { -INF    , -INF  , 32 - 33, INF     }, // CORNER_W, clip 33 pixels from right
02053   { -INF    ,  0 + 7, INF    , INF     }, // CORNER_S, clip 7 pixels from top
02054   { -31 + 33, -INF  , INF    , INF     }, // CORNER_E, clip 33 pixels from left
02055   { -INF    , -INF  , INF    , 30 - 23 }  // CORNER_N, clip 23 pixels from bottom
02056 };
02057 
02058 static inline void DrawTrackSprite(SpriteID sprite, PaletteID pal, const TileInfo *ti, Slope s)
02059 {
02060   DrawGroundSprite(sprite, pal, NULL, 0, (ti->tileh & s) ? -8 : 0);
02061 }
02062 
02063 static void DrawTrackBitsOverlay(TileInfo *ti, TrackBits track, const RailtypeInfo *rti)
02064 {
02065   RailGroundType rgt = GetRailGroundType(ti->tile);
02066   Foundation f = GetRailFoundation(ti->tileh, track);
02067   Corner halftile_corner = CORNER_INVALID;
02068 
02069   if (IsNonContinuousFoundation(f)) {
02070     /* Save halftile corner */
02071     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
02072     /* Draw lower part first */
02073     track &= ~CornerToTrackBits(halftile_corner);
02074     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
02075   }
02076 
02077   DrawFoundation(ti, f);
02078   /* DrawFoundation modifies ti */
02079 
02080   /* Draw ground */
02081   if (rgt == RAIL_GROUND_WATER) {
02082     if (track != TRACK_BIT_NONE || IsSteepSlope(ti->tileh)) {
02083       /* three-corner-raised slope or steep slope with track on upper part */
02084       DrawShoreTile(ti->tileh);
02085     } else {
02086       /* single-corner-raised slope with track on upper part */
02087       DrawGroundSprite(SPR_FLAT_WATER_TILE, PAL_NONE);
02088     }
02089   } else {
02090     SpriteID image;
02091 
02092     switch (rgt) {
02093       case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
02094       case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOW_DESERT_TILE; break;
02095       default:                     image = SPR_FLAT_GRASS_TILE; break;
02096     }
02097 
02098     image += SlopeToSpriteOffset(ti->tileh);
02099 
02100     DrawGroundSprite(image, PAL_NONE);
02101   }
02102 
02103   SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
02104   SpriteID ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND);
02105   TrackBits pbs = _settings_client.gui.show_track_reservation ? GetRailReservationTrackBits(ti->tile) : TRACK_BIT_NONE;
02106 
02107   if (track == TRACK_BIT_NONE) {
02108     /* Half-tile foundation, no track here? */
02109   } else if (ti->tileh == SLOPE_NW && track == TRACK_BIT_Y) {
02110     DrawGroundSprite(ground + RTO_SLOPE_NW, PAL_NONE);
02111     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 9, PALETTE_CRASH);
02112   } else if (ti->tileh == SLOPE_NE && track == TRACK_BIT_X) {
02113     DrawGroundSprite(ground + RTO_SLOPE_NE, PAL_NONE);
02114     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 6, PALETTE_CRASH);
02115   } else if (ti->tileh == SLOPE_SE && track == TRACK_BIT_Y) {
02116     DrawGroundSprite(ground + RTO_SLOPE_SE, PAL_NONE);
02117     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 7, PALETTE_CRASH);
02118   } else if (ti->tileh == SLOPE_SW && track == TRACK_BIT_X) {
02119     DrawGroundSprite(ground + RTO_SLOPE_SW, PAL_NONE);
02120     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 8, PALETTE_CRASH);
02121   } else {
02122     switch (track) {
02123       /* Draw single ground sprite when not overlapping. No track overlay
02124        * is necessary for these sprites. */
02125       case TRACK_BIT_X:     DrawGroundSprite(ground + RTO_X, PAL_NONE); break;
02126       case TRACK_BIT_Y:     DrawGroundSprite(ground + RTO_Y, PAL_NONE); break;
02127       case TRACK_BIT_UPPER: DrawTrackSprite(ground + RTO_N, PAL_NONE, ti, SLOPE_N); break;
02128       case TRACK_BIT_LOWER: DrawTrackSprite(ground + RTO_S, PAL_NONE, ti, SLOPE_S); break;
02129       case TRACK_BIT_RIGHT: DrawTrackSprite(ground + RTO_E, PAL_NONE, ti, SLOPE_E); break;
02130       case TRACK_BIT_LEFT:  DrawTrackSprite(ground + RTO_W, PAL_NONE, ti, SLOPE_W); break;
02131       case TRACK_BIT_CROSS: DrawGroundSprite(ground + RTO_CROSSING_XY, PAL_NONE); break;
02132       case TRACK_BIT_HORZ:  DrawTrackSprite(ground + RTO_N, PAL_NONE, ti, SLOPE_N);
02133                             DrawTrackSprite(ground + RTO_S, PAL_NONE, ti, SLOPE_S); break;
02134       case TRACK_BIT_VERT:  DrawTrackSprite(ground + RTO_E, PAL_NONE, ti, SLOPE_E);
02135                             DrawTrackSprite(ground + RTO_W, PAL_NONE, ti, SLOPE_W); break;
02136 
02137       default:
02138         /* We're drawing a junction tile */
02139         if ((track & TRACK_BIT_3WAY_NE) == 0) {
02140           DrawGroundSprite(ground + RTO_JUNCTION_SW, PAL_NONE);
02141         } else if ((track & TRACK_BIT_3WAY_SW) == 0) {
02142           DrawGroundSprite(ground + RTO_JUNCTION_NE, PAL_NONE);
02143         } else if ((track & TRACK_BIT_3WAY_NW) == 0) {
02144           DrawGroundSprite(ground + RTO_JUNCTION_SE, PAL_NONE);
02145         } else if ((track & TRACK_BIT_3WAY_SE) == 0) {
02146           DrawGroundSprite(ground + RTO_JUNCTION_NW, PAL_NONE);
02147         } else {
02148           DrawGroundSprite(ground + RTO_JUNCTION_NSEW, PAL_NONE);
02149         }
02150 
02151         /* Mask out PBS bits as we shall draw them afterwards anyway. */
02152         track &= ~pbs;
02153 
02154         /* Draw regular track bits */
02155         if (track & TRACK_BIT_X)     DrawGroundSprite(overlay + RTO_X, PAL_NONE);
02156         if (track & TRACK_BIT_Y)     DrawGroundSprite(overlay + RTO_Y, PAL_NONE);
02157         if (track & TRACK_BIT_UPPER) DrawGroundSprite(overlay + RTO_N, PAL_NONE);
02158         if (track & TRACK_BIT_LOWER) DrawGroundSprite(overlay + RTO_S, PAL_NONE);
02159         if (track & TRACK_BIT_RIGHT) DrawGroundSprite(overlay + RTO_E, PAL_NONE);
02160         if (track & TRACK_BIT_LEFT)  DrawGroundSprite(overlay + RTO_W, PAL_NONE);
02161     }
02162 
02163     /* Draw reserved track bits */
02164     if (pbs & TRACK_BIT_X)     DrawGroundSprite(overlay + RTO_X, PALETTE_CRASH);
02165     if (pbs & TRACK_BIT_Y)     DrawGroundSprite(overlay + RTO_Y, PALETTE_CRASH);
02166     if (pbs & TRACK_BIT_UPPER) DrawTrackSprite(overlay + RTO_N, PALETTE_CRASH, ti, SLOPE_N);
02167     if (pbs & TRACK_BIT_LOWER) DrawTrackSprite(overlay + RTO_S, PALETTE_CRASH, ti, SLOPE_S);
02168     if (pbs & TRACK_BIT_RIGHT) DrawTrackSprite(overlay + RTO_E, PALETTE_CRASH, ti, SLOPE_E);
02169     if (pbs & TRACK_BIT_LEFT)  DrawTrackSprite(overlay + RTO_W, PALETTE_CRASH, ti, SLOPE_W);
02170   }
02171 
02172   if (IsValidCorner(halftile_corner)) {
02173     DrawFoundation(ti, HalftileFoundation(halftile_corner));
02174     overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY, TCX_UPPER_HALFTILE);
02175     ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND, TCX_UPPER_HALFTILE);
02176 
02177     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
02178     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
02179 
02180     SpriteID image;
02181     switch (rgt) {
02182       case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
02183       case RAIL_GROUND_ICE_DESERT:
02184       case RAIL_GROUND_HALF_SNOW:  image = SPR_FLAT_SNOW_DESERT_TILE; break;
02185       default:                     image = SPR_FLAT_GRASS_TILE; break;
02186     }
02187 
02188     image += SlopeToSpriteOffset(fake_slope);
02189 
02190     DrawGroundSprite(image, PAL_NONE, &(_halftile_sub_sprite[halftile_corner]));
02191 
02192     track = CornerToTrackBits(halftile_corner);
02193 
02194     int offset;
02195     switch (track) {
02196       default: NOT_REACHED();
02197       case TRACK_BIT_UPPER: offset = RTO_N; break;
02198       case TRACK_BIT_LOWER: offset = RTO_S; break;
02199       case TRACK_BIT_RIGHT: offset = RTO_E; break;
02200       case TRACK_BIT_LEFT:  offset = RTO_W; break;
02201     }
02202 
02203     DrawTrackSprite(ground + offset, PAL_NONE, ti, fake_slope);
02204     if (_settings_client.gui.show_track_reservation && HasReservedTracks(ti->tile, track)) {
02205       DrawTrackSprite(overlay + offset, PALETTE_CRASH, ti, fake_slope);
02206     }
02207   }
02208 }
02209 
02215 static void DrawTrackBits(TileInfo *ti, TrackBits track)
02216 {
02217   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
02218 
02219   if (rti->UsesOverlay()) {
02220     DrawTrackBitsOverlay(ti, track, rti);
02221     return;
02222   }
02223 
02224   RailGroundType rgt = GetRailGroundType(ti->tile);
02225   Foundation f = GetRailFoundation(ti->tileh, track);
02226   Corner halftile_corner = CORNER_INVALID;
02227 
02228   if (IsNonContinuousFoundation(f)) {
02229     /* Save halftile corner */
02230     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
02231     /* Draw lower part first */
02232     track &= ~CornerToTrackBits(halftile_corner);
02233     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
02234   }
02235 
02236   DrawFoundation(ti, f);
02237   /* DrawFoundation modifies ti */
02238 
02239   SpriteID image;
02240   PaletteID pal = PAL_NONE;
02241   const SubSprite *sub = NULL;
02242   bool junction = false;
02243 
02244   /* Select the sprite to use. */
02245   if (track == 0) {
02246     /* Clear ground (only track on halftile foundation) */
02247     if (rgt == RAIL_GROUND_WATER) {
02248       if (IsSteepSlope(ti->tileh)) {
02249         DrawShoreTile(ti->tileh);
02250         image = 0;
02251       } else {
02252         image = SPR_FLAT_WATER_TILE;
02253       }
02254     } else {
02255       switch (rgt) {
02256         case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
02257         case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOW_DESERT_TILE; break;
02258         default:                     image = SPR_FLAT_GRASS_TILE; break;
02259       }
02260       image += SlopeToSpriteOffset(ti->tileh);
02261     }
02262   } else {
02263     if (ti->tileh != SLOPE_FLAT) {
02264       /* track on non-flat ground */
02265       image = _track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.track_y;
02266     } else {
02267       /* track on flat ground */
02268       (image = rti->base_sprites.track_y, track == TRACK_BIT_Y) ||
02269       (image++,                           track == TRACK_BIT_X) ||
02270       (image++,                           track == TRACK_BIT_UPPER) ||
02271       (image++,                           track == TRACK_BIT_LOWER) ||
02272       (image++,                           track == TRACK_BIT_RIGHT) ||
02273       (image++,                           track == TRACK_BIT_LEFT) ||
02274       (image++,                           track == TRACK_BIT_CROSS) ||
02275 
02276       (image = rti->base_sprites.track_ns, track == TRACK_BIT_HORZ) ||
02277       (image++,                            track == TRACK_BIT_VERT) ||
02278 
02279       (junction = true, false) ||
02280       (image = rti->base_sprites.ground, (track & TRACK_BIT_3WAY_NE) == 0) ||
02281       (image++,                          (track & TRACK_BIT_3WAY_SW) == 0) ||
02282       (image++,                          (track & TRACK_BIT_3WAY_NW) == 0) ||
02283       (image++,                          (track & TRACK_BIT_3WAY_SE) == 0) ||
02284       (image++, true);
02285     }
02286 
02287     switch (rgt) {
02288       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
02289       case RAIL_GROUND_ICE_DESERT: image += rti->snow_offset;  break;
02290       case RAIL_GROUND_WATER: {
02291         /* three-corner-raised slope */
02292         DrawShoreTile(ti->tileh);
02293         Corner track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
02294         sub = &(_halftile_sub_sprite[track_corner]);
02295         break;
02296       }
02297       default: break;
02298     }
02299   }
02300 
02301   if (image != 0) DrawGroundSprite(image, pal, sub);
02302 
02303   /* Draw track pieces individually for junction tiles */
02304   if (junction) {
02305     if (track & TRACK_BIT_X)     DrawGroundSprite(rti->base_sprites.single_x, PAL_NONE);
02306     if (track & TRACK_BIT_Y)     DrawGroundSprite(rti->base_sprites.single_y, PAL_NONE);
02307     if (track & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PAL_NONE);
02308     if (track & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PAL_NONE);
02309     if (track & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PAL_NONE);
02310     if (track & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PAL_NONE);
02311   }
02312 
02313   /* PBS debugging, draw reserved tracks darker */
02314   if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation) {
02315     /* Get reservation, but mask track on halftile slope */
02316     TrackBits pbs = GetRailReservationTrackBits(ti->tile) & track;
02317     if (pbs & TRACK_BIT_X) {
02318       if (ti->tileh == SLOPE_FLAT || ti->tileh == SLOPE_ELEVATED) {
02319         DrawGroundSprite(rti->base_sprites.single_x, PALETTE_CRASH);
02320       } else {
02321         DrawGroundSprite(_track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.single_sloped - 20, PALETTE_CRASH);
02322       }
02323     }
02324     if (pbs & TRACK_BIT_Y) {
02325       if (ti->tileh == SLOPE_FLAT || ti->tileh == SLOPE_ELEVATED) {
02326         DrawGroundSprite(rti->base_sprites.single_y, PALETTE_CRASH);
02327       } else {
02328         DrawGroundSprite(_track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.single_sloped - 20, PALETTE_CRASH);
02329       }
02330     }
02331     if (pbs & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_N ? -(int)TILE_HEIGHT : 0);
02332     if (pbs & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_S ? -(int)TILE_HEIGHT : 0);
02333     if (pbs & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_W ? -(int)TILE_HEIGHT : 0);
02334     if (pbs & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_E ? -(int)TILE_HEIGHT : 0);
02335   }
02336 
02337   if (IsValidCorner(halftile_corner)) {
02338     DrawFoundation(ti, HalftileFoundation(halftile_corner));
02339 
02340     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
02341     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
02342     image = _track_sloped_sprites[fake_slope - 1] + rti->base_sprites.track_y;
02343     pal = PAL_NONE;
02344     switch (rgt) {
02345       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
02346       case RAIL_GROUND_ICE_DESERT:
02347       case RAIL_GROUND_HALF_SNOW:  image += rti->snow_offset;  break; // higher part has snow in this case too
02348       default: break;
02349     }
02350     DrawGroundSprite(image, pal, &(_halftile_sub_sprite[halftile_corner]));
02351 
02352     if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasReservedTracks(ti->tile, CornerToTrackBits(halftile_corner))) {
02353       static const byte _corner_to_track_sprite[] = {3, 1, 2, 0};
02354       DrawGroundSprite(_corner_to_track_sprite[halftile_corner] + rti->base_sprites.single_n, PALETTE_CRASH, NULL, 0, -(int)TILE_HEIGHT);
02355     }
02356   }
02357 }
02358 
02366 enum SignalOffsets {
02367   SIGNAL_TO_SOUTHWEST =  0,
02368   SIGNAL_TO_NORTHEAST =  2,
02369   SIGNAL_TO_SOUTHEAST =  4,
02370   SIGNAL_TO_NORTHWEST =  6,
02371   SIGNAL_TO_EAST      =  8,
02372   SIGNAL_TO_WEST      = 10,
02373   SIGNAL_TO_SOUTH     = 12,
02374   SIGNAL_TO_NORTH     = 14,
02375 };
02376 
02377 static void DrawSignals(TileIndex tile, TrackBits rails)
02378 {
02379 #define MAYBE_DRAW_SIGNAL(x, y, z, t) if (IsSignalPresent(tile, x)) DrawSingleSignal(tile, t, GetSingleSignalState(tile, x), y, z)
02380 
02381   if (!(rails & TRACK_BIT_Y)) {
02382     if (!(rails & TRACK_BIT_X)) {
02383       if (rails & TRACK_BIT_LEFT) {
02384         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTH, 0, TRACK_LEFT);
02385         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTH, 1, TRACK_LEFT);
02386       }
02387       if (rails & TRACK_BIT_RIGHT) {
02388         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_NORTH, 2, TRACK_RIGHT);
02389         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_SOUTH, 3, TRACK_RIGHT);
02390       }
02391       if (rails & TRACK_BIT_UPPER) {
02392         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_WEST, 4, TRACK_UPPER);
02393         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_EAST, 5, TRACK_UPPER);
02394       }
02395       if (rails & TRACK_BIT_LOWER) {
02396         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_WEST, 6, TRACK_LOWER);
02397         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_EAST, 7, TRACK_LOWER);
02398       }
02399     } else {
02400       MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHWEST, 8, TRACK_X);
02401       MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHEAST, 9, TRACK_X);
02402     }
02403   } else {
02404     MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHEAST, 10, TRACK_Y);
02405     MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHWEST, 11, TRACK_Y);
02406   }
02407 }
02408 
02409 static void DrawTile_Track(TileInfo *ti)
02410 {
02411   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
02412 
02413   _drawtile_track_palette = COMPANY_SPRITE_COLOUR(GetTileOwner(ti->tile));
02414 
02415   if (IsPlainRail(ti->tile)) {
02416     TrackBits rails = GetTrackBits(ti->tile);
02417 
02418     DrawTrackBits(ti, rails);
02419 
02420     if (HasBit(_display_opt, DO_FULL_DETAIL)) DrawTrackDetails(ti, rti);
02421 
02422     if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
02423 
02424     if (HasSignals(ti->tile)) DrawSignals(ti->tile, rails);
02425   } else {
02426     /* draw depot */
02427     const DrawTileSprites *dts;
02428     PaletteID pal = PAL_NONE;
02429     SpriteID relocation;
02430 
02431     if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);
02432 
02433     if (IsInvisibilitySet(TO_BUILDINGS)) {
02434       /* Draw rail instead of depot */
02435       dts = &_depot_invisible_gfx_table[GetRailDepotDirection(ti->tile)];
02436     } else {
02437       dts = &_depot_gfx_table[GetRailDepotDirection(ti->tile)];
02438     }
02439 
02440     SpriteID image;
02441     if (rti->UsesOverlay()) {
02442       image = SPR_FLAT_GRASS_TILE;
02443     } else {
02444       image = dts->ground.sprite;
02445       if (image != SPR_FLAT_GRASS_TILE) image += rti->GetRailtypeSpriteOffset();
02446     }
02447 
02448     /* adjust ground tile for desert
02449      * don't adjust for snow, because snow in depots looks weird */
02450     if (IsSnowRailGround(ti->tile) && _settings_game.game_creation.landscape == LT_TROPIC) {
02451       if (image != SPR_FLAT_GRASS_TILE) {
02452         image += rti->snow_offset; // tile with tracks
02453       } else {
02454         image = SPR_FLAT_SNOW_DESERT_TILE; // flat ground
02455       }
02456     }
02457 
02458     DrawGroundSprite(image, GroundSpritePaletteTransform(image, pal, _drawtile_track_palette));
02459 
02460     if (rti->UsesOverlay()) {
02461       SpriteID ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND);
02462 
02463       switch (GetRailDepotDirection(ti->tile)) {
02464         case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02465         case DIAGDIR_SW: DrawGroundSprite(ground + RTO_X, PAL_NONE); break;
02466         case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02467         case DIAGDIR_SE: DrawGroundSprite(ground + RTO_Y, PAL_NONE); break;
02468         default: break;
02469       }
02470 
02471       if (_settings_client.gui.show_track_reservation && HasDepotReservation(ti->tile)) {
02472         SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
02473 
02474         switch (GetRailDepotDirection(ti->tile)) {
02475           case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02476           case DIAGDIR_SW: DrawGroundSprite(overlay + RTO_X, PALETTE_CRASH); break;
02477           case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02478           case DIAGDIR_SE: DrawGroundSprite(overlay + RTO_Y, PALETTE_CRASH); break;
02479           default: break;
02480         }
02481       }
02482 
02483       int depot_sprite = GetCustomRailSprite(rti, ti->tile, RTSG_DEPOT);
02484       relocation = depot_sprite != 0 ? depot_sprite - SPR_RAIL_DEPOT_SE_1 : rti->GetRailtypeSpriteOffset();
02485     } else {
02486       /* PBS debugging, draw reserved tracks darker */
02487       if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasDepotReservation(ti->tile)) {
02488         switch (GetRailDepotDirection(ti->tile)) {
02489           case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02490           case DIAGDIR_SW: DrawGroundSprite(rti->base_sprites.single_x, PALETTE_CRASH); break;
02491           case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02492           case DIAGDIR_SE: DrawGroundSprite(rti->base_sprites.single_y, PALETTE_CRASH); break;
02493           default: break;
02494         }
02495       }
02496 
02497       relocation = rti->GetRailtypeSpriteOffset();
02498     }
02499 
02500     if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
02501 
02502     DrawRailTileSeq(ti, dts, TO_BUILDINGS, relocation, 0, _drawtile_track_palette);
02503   }
02504   DrawBridgeMiddle(ti);
02505 }
02506 
02507 void DrawTrainDepotSprite(int x, int y, int dir, RailType railtype)
02508 {
02509   const DrawTileSprites *dts = &_depot_gfx_table[dir];
02510   const RailtypeInfo *rti = GetRailTypeInfo(railtype);
02511   SpriteID image = rti->UsesOverlay() ? SPR_FLAT_GRASS_TILE : dts->ground.sprite;
02512   uint32 offset = rti->GetRailtypeSpriteOffset();
02513 
02514   x += 33;
02515   y += 17;
02516 
02517   if (image != SPR_FLAT_GRASS_TILE) image += offset;
02518   PaletteID palette = COMPANY_SPRITE_COLOUR(_local_company);
02519 
02520   DrawSprite(image, PAL_NONE, x, y);
02521 
02522   if (rti->UsesOverlay()) {
02523     SpriteID ground = GetCustomRailSprite(rti, INVALID_TILE, RTSG_GROUND);
02524 
02525     switch (dir) {
02526       case DIAGDIR_SW: DrawSprite(ground + RTO_X, PAL_NONE, x, y); break;
02527       case DIAGDIR_SE: DrawSprite(ground + RTO_Y, PAL_NONE, x, y); break;
02528       default: break;
02529     }
02530 
02531     int depot_sprite = GetCustomRailSprite(rti, INVALID_TILE, RTSG_DEPOT);
02532     if (depot_sprite != 0) offset = depot_sprite - SPR_RAIL_DEPOT_SE_1;
02533   }
02534 
02535   DrawRailTileSeqInGUI(x, y, dts, offset, 0, palette);
02536 }
02537 
02538 static uint GetSlopeZ_Track(TileIndex tile, uint x, uint y)
02539 {
02540   uint z;
02541   Slope tileh = GetTileSlope(tile, &z);
02542 
02543   if (tileh == SLOPE_FLAT) return z;
02544   if (IsPlainRail(tile)) {
02545     z += ApplyFoundationToSlope(GetRailFoundation(tileh, GetTrackBits(tile)), &tileh);
02546     return z + GetPartialZ(x & 0xF, y & 0xF, tileh);
02547   } else {
02548     return z + TILE_HEIGHT;
02549   }
02550 }
02551 
02552 static Foundation GetFoundation_Track(TileIndex tile, Slope tileh)
02553 {
02554   return IsPlainRail(tile) ? GetRailFoundation(tileh, GetTrackBits(tile)) : FlatteningFoundation(tileh);
02555 }
02556 
02557 static void TileLoop_Track(TileIndex tile)
02558 {
02559   RailGroundType old_ground = GetRailGroundType(tile);
02560   RailGroundType new_ground;
02561 
02562   ReduceStuckCounter(tile);
02563 
02564   if (old_ground == RAIL_GROUND_WATER) {
02565     TileLoop_Water(tile);
02566     return;
02567   }
02568 
02569   switch (_settings_game.game_creation.landscape) {
02570     case LT_ARCTIC: {
02571       uint z;
02572       Slope slope = GetTileSlope(tile, &z);
02573       bool half = false;
02574 
02575       /* for non-flat track, use lower part of track
02576        * in other cases, use the highest part with track */
02577       if (IsPlainRail(tile)) {
02578         TrackBits track = GetTrackBits(tile);
02579         Foundation f = GetRailFoundation(slope, track);
02580 
02581         switch (f) {
02582           case FOUNDATION_NONE:
02583             /* no foundation - is the track on the upper side of three corners raised tile? */
02584             if (IsSlopeWithThreeCornersRaised(slope)) z += TILE_HEIGHT;
02585             break;
02586 
02587           case FOUNDATION_INCLINED_X:
02588           case FOUNDATION_INCLINED_Y:
02589             /* sloped track - is it on a steep slope? */
02590             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
02591             break;
02592 
02593           case FOUNDATION_STEEP_LOWER:
02594             /* only lower part of steep slope */
02595             z += TILE_HEIGHT;
02596             break;
02597 
02598           default:
02599             /* if it is a steep slope, then there is a track on higher part */
02600             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
02601             z += TILE_HEIGHT;
02602             break;
02603         }
02604 
02605         half = IsInsideMM(f, FOUNDATION_STEEP_BOTH, FOUNDATION_HALFTILE_N + 1);
02606       } else {
02607         /* is the depot on a non-flat tile? */
02608         if (slope != SLOPE_FLAT) z += TILE_HEIGHT;
02609       }
02610 
02611       /* 'z' is now the lowest part of the highest track bit -
02612        * for sloped track, it is 'z' of lower part
02613        * for two track bits, it is 'z' of higher track bit
02614        * For non-continuous foundations (and STEEP_BOTH), 'half' is set */
02615       if (z > GetSnowLine()) {
02616         if (half && z - GetSnowLine() == TILE_HEIGHT) {
02617           /* track on non-continuous foundation, lower part is not under snow */
02618           new_ground = RAIL_GROUND_HALF_SNOW;
02619         } else {
02620           new_ground = RAIL_GROUND_ICE_DESERT;
02621         }
02622         goto set_ground;
02623       }
02624       break;
02625       }
02626 
02627     case LT_TROPIC:
02628       if (GetTropicZone(tile) == TROPICZONE_DESERT) {
02629         new_ground = RAIL_GROUND_ICE_DESERT;
02630         goto set_ground;
02631       }
02632       break;
02633   }
02634 
02635   new_ground = RAIL_GROUND_GRASS;
02636 
02637   if (IsPlainRail(tile) && old_ground != RAIL_GROUND_BARREN) { // wait until bottom is green
02638     /* determine direction of fence */
02639     TrackBits rail = GetTrackBits(tile);
02640 
02641     switch (rail) {
02642       case TRACK_BIT_UPPER: new_ground = RAIL_GROUND_FENCE_HORIZ1; break;
02643       case TRACK_BIT_LOWER: new_ground = RAIL_GROUND_FENCE_HORIZ2; break;
02644       case TRACK_BIT_LEFT:  new_ground = RAIL_GROUND_FENCE_VERT1;  break;
02645       case TRACK_BIT_RIGHT: new_ground = RAIL_GROUND_FENCE_VERT2;  break;
02646 
02647       default: {
02648         Owner owner = GetTileOwner(tile);
02649 
02650         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_RIGHT) || (
02651               (rail & TRACK_BIT_3WAY_NW) == 0 &&
02652               (rail & TRACK_BIT_X)
02653             )) {
02654           TileIndex n = tile + TileDiffXY(0, -1);
02655           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02656 
02657           if (!IsTileType(n, MP_RAILWAY) ||
02658               !IsTileOwner(n, owner) ||
02659               nrail == TRACK_BIT_UPPER ||
02660               nrail == TRACK_BIT_LEFT) {
02661             new_ground = RAIL_GROUND_FENCE_NW;
02662           }
02663         }
02664 
02665         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_LEFT) || (
02666               (rail & TRACK_BIT_3WAY_SE) == 0 &&
02667               (rail & TRACK_BIT_X)
02668             )) {
02669           TileIndex n = tile + TileDiffXY(0, 1);
02670           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02671 
02672           if (!IsTileType(n, MP_RAILWAY) ||
02673               !IsTileOwner(n, owner) ||
02674               nrail == TRACK_BIT_LOWER ||
02675               nrail == TRACK_BIT_RIGHT) {
02676             new_ground = (new_ground == RAIL_GROUND_FENCE_NW) ?
02677               RAIL_GROUND_FENCE_SENW : RAIL_GROUND_FENCE_SE;
02678           }
02679         }
02680 
02681         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_LEFT) || (
02682               (rail & TRACK_BIT_3WAY_NE) == 0 &&
02683               (rail & TRACK_BIT_Y)
02684             )) {
02685           TileIndex n = tile + TileDiffXY(-1, 0);
02686           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02687 
02688           if (!IsTileType(n, MP_RAILWAY) ||
02689               !IsTileOwner(n, owner) ||
02690               nrail == TRACK_BIT_UPPER ||
02691               nrail == TRACK_BIT_RIGHT) {
02692             new_ground = RAIL_GROUND_FENCE_NE;
02693           }
02694         }
02695 
02696         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_RIGHT) || (
02697               (rail & TRACK_BIT_3WAY_SW) == 0 &&
02698               (rail & TRACK_BIT_Y)
02699             )) {
02700           TileIndex n = tile + TileDiffXY(1, 0);
02701           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02702 
02703           if (!IsTileType(n, MP_RAILWAY) ||
02704               !IsTileOwner(n, owner) ||
02705               nrail == TRACK_BIT_LOWER ||
02706               nrail == TRACK_BIT_LEFT) {
02707             new_ground = (new_ground == RAIL_GROUND_FENCE_NE) ?
02708               RAIL_GROUND_FENCE_NESW : RAIL_GROUND_FENCE_SW;
02709           }
02710         }
02711         break;
02712       }
02713     }
02714   }
02715 
02716 set_ground:
02717   if (old_ground != new_ground) {
02718     SetRailGroundType(tile, new_ground);
02719     MarkTileDirtyByTile(tile);
02720   }
02721 }
02722 
02723 
02724 static TrackStatus GetTileTrackStatus_Track(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
02725 {
02726   /* Case of half tile slope with water. */
02727   if (mode == TRANSPORT_WATER && IsPlainRail(tile) && GetRailGroundType(tile) == RAIL_GROUND_WATER) {
02728     TrackBits tb = GetTrackBits(tile);
02729     switch (tb) {
02730       default: NOT_REACHED();
02731       case TRACK_BIT_UPPER: tb = TRACK_BIT_LOWER; break;
02732       case TRACK_BIT_LOWER: tb = TRACK_BIT_UPPER; break;
02733       case TRACK_BIT_LEFT:  tb = TRACK_BIT_RIGHT; break;
02734       case TRACK_BIT_RIGHT: tb = TRACK_BIT_LEFT;  break;
02735     }
02736     return CombineTrackStatus(TrackBitsToTrackdirBits(tb), TRACKDIR_BIT_NONE);
02737   }
02738 
02739   if (mode != TRANSPORT_RAIL) return 0;
02740 
02741   TrackBits trackbits = TRACK_BIT_NONE;
02742   TrackdirBits red_signals = TRACKDIR_BIT_NONE;
02743 
02744   switch (GetRailTileType(tile)) {
02745     default: NOT_REACHED();
02746     case RAIL_TILE_NORMAL:
02747       trackbits = GetTrackBits(tile);
02748       break;
02749 
02750     case RAIL_TILE_SIGNALS: {
02751       trackbits = GetTrackBits(tile);
02752       byte a = GetPresentSignals(tile);
02753       uint b = GetSignalStates(tile);
02754 
02755       b &= a;
02756 
02757       /* When signals are not present (in neither direction),
02758        * we pretend them to be green. Otherwise, it depends on
02759        * the signal type. For signals that are only active from
02760        * one side, we set the missing signals explicitely to
02761        * `green'. Otherwise, they implicitely become `red'. */
02762       if (!IsOnewaySignal(tile, TRACK_UPPER) || (a & SignalOnTrack(TRACK_UPPER)) == 0) b |= ~a & SignalOnTrack(TRACK_UPPER);
02763       if (!IsOnewaySignal(tile, TRACK_LOWER) || (a & SignalOnTrack(TRACK_LOWER)) == 0) b |= ~a & SignalOnTrack(TRACK_LOWER);
02764 
02765       if ((b & 0x8) == 0) red_signals |= (TRACKDIR_BIT_LEFT_N | TRACKDIR_BIT_X_NE | TRACKDIR_BIT_Y_SE | TRACKDIR_BIT_UPPER_E);
02766       if ((b & 0x4) == 0) red_signals |= (TRACKDIR_BIT_LEFT_S | TRACKDIR_BIT_X_SW | TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_UPPER_W);
02767       if ((b & 0x2) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_N | TRACKDIR_BIT_LOWER_E);
02768       if ((b & 0x1) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_S | TRACKDIR_BIT_LOWER_W);
02769 
02770       break;
02771     }
02772 
02773     case RAIL_TILE_DEPOT: {
02774       DiagDirection dir = GetRailDepotDirection(tile);
02775 
02776       if (side != INVALID_DIAGDIR && side != dir) break;
02777 
02778       trackbits = DiagDirToDiagTrackBits(dir);
02779       break;
02780     }
02781   }
02782 
02783   return CombineTrackStatus(TrackBitsToTrackdirBits(trackbits), red_signals);
02784 }
02785 
02786 static bool ClickTile_Track(TileIndex tile)
02787 {
02788   if (!IsRailDepot(tile)) return false;
02789 
02790   ShowDepotWindow(tile, VEH_TRAIN);
02791   return true;
02792 }
02793 
02794 static void GetTileDesc_Track(TileIndex tile, TileDesc *td)
02795 {
02796   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(tile));
02797   td->rail_speed = rti->max_speed;
02798   td->owner[0] = GetTileOwner(tile);
02799   switch (GetRailTileType(tile)) {
02800     case RAIL_TILE_NORMAL:
02801       td->str = STR_LAI_RAIL_DESCRIPTION_TRACK;
02802       break;
02803 
02804     case RAIL_TILE_SIGNALS: {
02805       static const StringID signal_type[8][8] = {
02806         {
02807           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SIGNALS,
02808           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
02809           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_EXITSIGNALS,
02810           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_COMBOSIGNALS,
02811           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PBSSIGNALS,
02812           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_NOENTRYSIGNALS,
02813           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PROGSIGNALS,
02814           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SPEEDSIGNALS
02815         },
02816         {
02817           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
02818           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRESIGNALS,
02819           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_EXITSIGNALS,
02820           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_COMBOSIGNALS,
02821           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PBSSIGNALS,
02822           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_NOENTRYSIGNALS,
02823           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PROGSIGNALS,
02824           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_SPEEDSIGNALS
02825         },
02826         {
02827           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_EXITSIGNALS,
02828           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_EXITSIGNALS,
02829           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXITSIGNALS,
02830           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_COMBOSIGNALS,
02831           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PBSSIGNALS,
02832           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_NOENTRYSIGNALS,
02833           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PROGSIGNALS,
02834           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_SPEEDSIGNALS
02835         },
02836         {
02837           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_COMBOSIGNALS,
02838           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_COMBOSIGNALS,
02839           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_COMBOSIGNALS,
02840           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBOSIGNALS,
02841           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PBSSIGNALS,
02842           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS,
02843           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PROGSIGNALS,
02844           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_SPEEDSIGNALS
02845         },
02846         {
02847           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PBSSIGNALS,
02848           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PBSSIGNALS,
02849           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PBSSIGNALS,
02850           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PBSSIGNALS,
02851           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBSSIGNALS,
02852           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS,
02853           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_PROGSIGNALS,
02854           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_SPEEDSIGNALS
02855         },
02856         {
02857           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_NOENTRYSIGNALS,
02858           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_NOENTRYSIGNALS,
02859           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_NOENTRYSIGNALS,
02860           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS,
02861           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS,
02862           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRYSIGNALS,
02863           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRY_PROGSIGNALS,
02864           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRY_SPEEDSIGNALS
02865         },
02866         {
02867           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PROGSIGNALS,
02868           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PROGSIGNALS,
02869           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PROGSIGNALS,
02870           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PROGSIGNALS,
02871           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_PROGSIGNALS,
02872           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRY_PROGSIGNALS,
02873           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PROGSIGNALS,
02874           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PROG_SPEEDSIGNALS
02875         },
02876         {
02877           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SPEEDSIGNALS,
02878           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_SPEEDSIGNALS,
02879           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_SPEEDSIGNALS,
02880           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_SPEEDSIGNALS,
02881           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_SPEEDSIGNALS,
02882           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRY_SPEEDSIGNALS,
02883           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PROG_SPEEDSIGNALS,
02884           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_SPEEDSIGNALS
02885         }
02886       };
02887 
02888       SignalType primary_signal;
02889       SignalType secondary_signal;
02890       if (HasSignalOnTrack(tile, TRACK_UPPER)) {
02891         primary_signal = GetSignalType(tile, TRACK_UPPER);
02892         secondary_signal = HasSignalOnTrack(tile, TRACK_LOWER) ? GetSignalType(tile, TRACK_LOWER) : primary_signal;
02893       } else {
02894         secondary_signal = primary_signal = GetSignalType(tile, TRACK_LOWER);
02895       }
02896 
02897       td->str = signal_type[secondary_signal][primary_signal];
02898       break;
02899     }
02900 
02901     case RAIL_TILE_DEPOT:
02902       td->str = STR_LAI_RAIL_DESCRIPTION_TRAIN_DEPOT;
02903       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) {
02904         if (td->rail_speed > 0) {
02905           td->rail_speed = min(td->rail_speed, 61);
02906         } else {
02907           td->rail_speed = 61;
02908         }
02909       }
02910       td->build_date = Depot::GetByTile(tile)->build_date;
02911       break;
02912 
02913     default:
02914       NOT_REACHED();
02915   }
02916 }
02917 
02918 static void ChangeTileOwner_Track(TileIndex tile, Owner old_owner, Owner new_owner)
02919 {
02920   if (!IsTileOwner(tile, old_owner)) return;
02921 
02922   if (new_owner != INVALID_OWNER) {
02923     /* Update company infrastructure counts. No need to dirty windows here, we'll redraw the whole screen anyway. */
02924     uint num_pieces = 1;
02925     if (IsPlainRail(tile)) {
02926       TrackBits bits = GetTrackBits(tile);
02927       num_pieces = CountBits(bits);
02928       if (TracksOverlap(bits)) num_pieces *= num_pieces;
02929     }
02930     RailType rt = GetRailType(tile);
02931     Company::Get(old_owner)->rail_infrastructure[rt] -= num_pieces;
02932     Company::Get(new_owner)->rail_infrastructure[rt] += num_pieces;
02933 
02934     if (HasSignals(tile)) {
02935       uint num_sigs = CountBits(GetPresentSignals(tile));
02936       Company::Get(old_owner)->signal_infrastructure -= num_sigs;
02937       Company::Get(new_owner)->signal_infrastructure += num_sigs;
02938     }
02939 
02940     SetTileOwner(tile, new_owner);
02941   } else {
02942     DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR);
02943   }
02944 }
02945 
02946 static const byte _fractcoords_behind[4] = { 0x8F, 0x8, 0x80, 0xF8 };
02947 static const byte _fractcoords_enter[4] = { 0x8A, 0x48, 0x84, 0xA8 };
02948 static const int8 _deltacoord_leaveoffset[8] = {
02949   -1,  0,  1,  0, /* x */
02950    0,  1,  0, -1  /* y */
02951 };
02952 
02953 
02960 int TicksToLeaveDepot(const Train *v)
02961 {
02962   DiagDirection dir = GetRailDepotDirection(v->tile);
02963   int length = v->gcache.cached_veh_length;
02964 
02965   switch (dir) {
02966     case DIAGDIR_NE: return  ((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) - (length + 1)));
02967     case DIAGDIR_SE: return -((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   + (length + 1)));
02968     case DIAGDIR_SW: return -((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) + (length + 1)));
02969     default:
02970     case DIAGDIR_NW: return  ((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   - (length + 1)));
02971   }
02972 
02973   return 0; // make compilers happy
02974 }
02975 
02980 static VehicleEnterTileStatus VehicleEnter_Track(Vehicle *u, TileIndex tile, int x, int y)
02981 {
02982   /* this routine applies only to trains in depot tiles */
02983   if (u->type != VEH_TRAIN || !IsRailDepotTile(tile)) return VETSB_CONTINUE;
02984 
02985   Train *v = Train::From(u);
02986 
02987   /* depot direction */
02988   DiagDirection dir = GetRailDepotDirection(tile);
02989 
02990   /* calculate the point where the following wagon should be activated
02991    * this depends on the length of the current vehicle */
02992   int length = v->gcache.cached_veh_length;
02993 
02994   byte fract_coord_leave =
02995     ((_fractcoords_enter[dir] & 0x0F) + // x
02996       (length + 1) * _deltacoord_leaveoffset[dir]) +
02997     (((_fractcoords_enter[dir] >> 4) +  // y
02998       ((length + 1) * _deltacoord_leaveoffset[dir + 4])) << 4);
02999 
03000   byte fract_coord = (x & 0xF) + ((y & 0xF) << 4);
03001 
03002   if (_fractcoords_behind[dir] == fract_coord) {
03003     /* make sure a train is not entering the tile from behind */
03004     return VETSB_CANNOT_ENTER;
03005   } else if (_fractcoords_enter[dir] == fract_coord) {
03006     if (DiagDirToDir(ReverseDiagDir(dir)) == v->direction) {
03007       /* enter the depot */
03008       v->track = TRACK_BIT_DEPOT,
03009       v->vehstatus |= VS_HIDDEN; // hide it
03010       v->direction = ReverseDir(v->direction);
03011       if (v->Next() == NULL) VehicleEnterDepot(v->First());
03012       v->tile = tile;
03013 
03014       InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
03015       return VETSB_ENTERED_WORMHOLE;
03016     }
03017   } else if (fract_coord_leave == fract_coord) {
03018     if (DiagDirToDir(dir) == v->direction) {
03019       /* leave the depot? */
03020       if ((v = v->Next()) != NULL) {
03021         v->vehstatus &= ~VS_HIDDEN;
03022         v->track = (DiagDirToAxis(dir) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y);
03023       }
03024     }
03025   }
03026 
03027   return VETSB_CONTINUE;
03028 }
03029 
03041 static CommandCost TestAutoslopeOnRailTile(TileIndex tile, uint flags, uint z_old, Slope tileh_old, uint z_new, Slope tileh_new, TrackBits rail_bits)
03042 {
03043   if (!_settings_game.construction.build_on_slopes || !AutoslopeEnabled()) return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
03044 
03045   /* Is the slope-rail_bits combination valid in general? I.e. is it safe to call GetRailFoundation() ? */
03046   if (CheckRailSlope(tileh_new, rail_bits, TRACK_BIT_NONE, tile).Failed()) return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
03047 
03048   /* Get the slopes on top of the foundations */
03049   z_old += ApplyFoundationToSlope(GetRailFoundation(tileh_old, rail_bits), &tileh_old);
03050   z_new += ApplyFoundationToSlope(GetRailFoundation(tileh_new, rail_bits), &tileh_new);
03051 
03052   Corner track_corner;
03053   switch (rail_bits) {
03054     case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
03055     case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
03056     case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
03057     case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
03058 
03059     /* Surface slope must not be changed */
03060     default:
03061       if (z_old != z_new || tileh_old != tileh_new) return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
03062       return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
03063   }
03064 
03065   /* The height of the track_corner must not be changed. The rest ensures GetRailFoundation() already. */
03066   z_old += GetSlopeZInCorner(RemoveHalftileSlope(tileh_old), track_corner);
03067   z_new += GetSlopeZInCorner(RemoveHalftileSlope(tileh_new), track_corner);
03068   if (z_old != z_new) return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
03069 
03070   CommandCost cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
03071   /* Make the ground dirty, if surface slope has changed */
03072   if (tileh_old != tileh_new) {
03073     /* If there is flat water on the lower halftile add the cost for clearing it */
03074     if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old)) cost.AddCost(_price[PR_CLEAR_WATER]);
03075     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
03076   }
03077   return  cost;
03078 }
03079 
03080 static CommandCost TerraformTile_Track(TileIndex tile, DoCommandFlag flags, uint z_new, Slope tileh_new)
03081 {
03082   uint z_old;
03083   Slope tileh_old = GetTileSlope(tile, &z_old);
03084   if (IsPlainRail(tile)) {
03085     TrackBits rail_bits = GetTrackBits(tile);
03086     /* Is there flat water on the lower halftile that must be cleared expensively? */
03087     bool was_water = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old));
03088 
03089     /* First test autoslope. However if it succeeds we still have to test the rest, because non-autoslope terraforming is cheaper. */
03090     CommandCost autoslope_result = TestAutoslopeOnRailTile(tile, flags, z_old, tileh_old, z_new, tileh_new, rail_bits);
03091 
03092     /* When there is only a single horizontal/vertical track, one corner can be terraformed. */
03093     Corner allowed_corner;
03094     switch (rail_bits) {
03095       case TRACK_BIT_RIGHT: allowed_corner = CORNER_W; break;
03096       case TRACK_BIT_UPPER: allowed_corner = CORNER_S; break;
03097       case TRACK_BIT_LEFT:  allowed_corner = CORNER_E; break;
03098       case TRACK_BIT_LOWER: allowed_corner = CORNER_N; break;
03099       default: return autoslope_result;
03100     }
03101 
03102     Foundation f_old = GetRailFoundation(tileh_old, rail_bits);
03103 
03104     /* Do not allow terraforming if allowed_corner is part of anti-zig-zag foundations */
03105     if (tileh_old != SLOPE_NS && tileh_old != SLOPE_EW && IsSpecialRailFoundation(f_old)) return autoslope_result;
03106 
03107     /* Everything is valid, which only changes allowed_corner */
03108     for (Corner corner = (Corner)0; corner < CORNER_END; corner = (Corner)(corner + 1)) {
03109       if (allowed_corner == corner) continue;
03110       if (z_old + GetSlopeZInCorner(tileh_old, corner) != z_new + GetSlopeZInCorner(tileh_new, corner)) return autoslope_result;
03111     }
03112 
03113     /* Make the ground dirty */
03114     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
03115 
03116     /* allow terraforming */
03117     return CommandCost(EXPENSES_CONSTRUCTION, was_water ? _price[PR_CLEAR_WATER] : (Money)0);
03118   } else if (_settings_game.construction.build_on_slopes && AutoslopeEnabled() &&
03119       AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRailDepotDirection(tile))) {
03120     return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
03121   }
03122   return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
03123 }
03124 
03125 
03126 extern const TileTypeProcs _tile_type_rail_procs = {
03127   DrawTile_Track,           // draw_tile_proc
03128   GetSlopeZ_Track,          // get_slope_z_proc
03129   ClearTile_Track,          // clear_tile_proc
03130   NULL,                     // add_accepted_cargo_proc
03131   GetTileDesc_Track,        // get_tile_desc_proc
03132   GetTileTrackStatus_Track, // get_tile_track_status_proc
03133   ClickTile_Track,          // click_tile_proc
03134   NULL,                     // animate_tile_proc
03135   TileLoop_Track,           // tile_loop_clear
03136   ChangeTileOwner_Track,    // change_tile_owner_clear
03137   NULL,                     // add_produced_cargo_proc
03138   VehicleEnter_Track,       // vehicle_enter_tile_proc
03139   GetFoundation_Track,      // get_foundation_proc
03140   TerraformTile_Track,      // terraform_tile_proc
03141 };