rail_cmd.cpp

Go to the documentation of this file.
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 
00036 #include "table/strings.h"
00037 #include "table/railtypes.h"
00038 #include "table/track_land.h"
00039 
00041 typedef SmallVector<Train *, 16> TrainList;
00042 
00043 RailtypeInfo _railtypes[RAILTYPE_END];
00044 
00045 assert_compile(sizeof(_original_railtypes) <= sizeof(_railtypes));
00046 
00050 void ResetRailTypes()
00051 {
00052   memset(_railtypes, 0, sizeof(_railtypes));
00053   memcpy(_railtypes, _original_railtypes, sizeof(_original_railtypes));
00054 }
00055 
00056 void ResolveRailTypeGUISprites(RailtypeInfo *rti)
00057 {
00058   SpriteID cursors_base = GetCustomRailSprite(rti, INVALID_TILE, RTSG_CURSORS);
00059   if (cursors_base != 0) {
00060     rti->gui_sprites.build_ns_rail = cursors_base +  0;
00061     rti->gui_sprites.build_x_rail  = cursors_base +  1;
00062     rti->gui_sprites.build_ew_rail = cursors_base +  2;
00063     rti->gui_sprites.build_y_rail  = cursors_base +  3;
00064     rti->gui_sprites.auto_rail     = cursors_base +  4;
00065     rti->gui_sprites.build_depot   = cursors_base +  5;
00066     rti->gui_sprites.build_tunnel  = cursors_base +  6;
00067     rti->gui_sprites.convert_rail  = cursors_base +  7;
00068     rti->cursor.rail_ns   = cursors_base +  8;
00069     rti->cursor.rail_swne = cursors_base +  9;
00070     rti->cursor.rail_ew   = cursors_base + 10;
00071     rti->cursor.rail_nwse = cursors_base + 11;
00072     rti->cursor.autorail  = cursors_base + 12;
00073     rti->cursor.depot     = cursors_base + 13;
00074     rti->cursor.tunnel    = cursors_base + 14;
00075     rti->cursor.convert   = cursors_base + 15;
00076   }
00077 }
00078 
00082 void InitRailTypes()
00083 {
00084   for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
00085     RailtypeInfo *rti = &_railtypes[rt];
00086     ResolveRailTypeGUISprites(rti);
00087   }
00088 }
00089 
00093 RailType AllocateRailType(RailTypeLabel label)
00094 {
00095   for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
00096     RailtypeInfo *rti = &_railtypes[rt];
00097 
00098     if (rti->label == 0) {
00099       /* Set up new rail type */
00100       memcpy(rti, &_railtypes[RAILTYPE_RAIL], sizeof(*rti));
00101       rti->label = label;
00102 
00103       /* Make us compatible with ourself. */
00104       rti->powered_railtypes    = (RailTypes)(1 << rt);
00105       rti->compatible_railtypes = (RailTypes)(1 << rt);
00106 
00107       /* We also introduce ourself. */
00108       rti->introduces_railtypes = (RailTypes)(1 << rt);
00109 
00110       /* Default sort order; order of allocation, but with some
00111        * offsets so it's easier for NewGRF to pick a spot without
00112        * changing the order of other (original) rail types.
00113        * The << is so you can place other railtypes in between the
00114        * other railtypes, the 7 is to be able to place something
00115        * before the first (default) rail type. */
00116       rti->sorting_order = rt << 4 | 7;
00117       return rt;
00118     }
00119   }
00120 
00121   return INVALID_RAILTYPE;
00122 }
00123 
00124 static const byte _track_sloped_sprites[14] = {
00125   14, 15, 22, 13,
00126    0, 21, 17, 12,
00127   23,  0, 18, 20,
00128   19, 16
00129 };
00130 
00131 
00132 /*         4
00133  *     ---------
00134  *    |\       /|
00135  *    | \    1/ |
00136  *    |  \   /  |
00137  *    |   \ /   |
00138  *  16|    \    |32
00139  *    |   / \2  |
00140  *    |  /   \  |
00141  *    | /     \ |
00142  *    |/       \|
00143  *     ---------
00144  *         8
00145  */
00146 
00147 
00148 
00149 /* MAP2 byte:    abcd???? => Signal On? Same coding as map3lo
00150  * MAP3LO byte:  abcd???? => Signal Exists?
00151  *               a and b are for diagonals, upper and left,
00152  *               one for each direction. (ie a == NE->SW, b ==
00153  *               SW->NE, or v.v., I don't know. b and c are
00154  *               similar for lower and right.
00155  * MAP2 byte:    ????abcd => Type of ground.
00156  * MAP3LO byte:  ????abcd => Type of rail.
00157  * MAP5:         00abcdef => rail
00158  *               01abcdef => rail w/ signals
00159  *               10uuuuuu => unused
00160  *               11uuuudd => rail depot
00161  */
00162 
00171 static CommandCost EnsureNoTrainOnTrack(TileIndex tile, Track track)
00172 {
00173   TrackBits rail_bits = TrackToTrackBits(track);
00174   return EnsureNoTrainOnTrackBits(tile, rail_bits);
00175 }
00176 
00184 static CommandCost CheckTrackCombination(TileIndex tile, TrackBits to_build, uint flags)
00185 {
00186   if (!IsPlainRail(tile)) return_cmd_error(STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION);
00187 
00188   /* So, we have a tile with tracks on it (and possibly signals). Let's see
00189    * what tracks first */
00190   TrackBits current = GetTrackBits(tile); // The current track layout.
00191   TrackBits future = current | to_build;  // The track layout we want to build.
00192 
00193   /* Are we really building something new? */
00194   if (current == future) {
00195     /* Nothing new is being built */
00196     return_cmd_error(STR_ERROR_ALREADY_BUILT);
00197   }
00198 
00199   /* Let's see if we may build this */
00200   if ((flags & DC_NO_RAIL_OVERLAP) || HasSignals(tile)) {
00201     /* If we are not allowed to overlap (flag is on for ai companies or we have
00202      * signals on the tile), check that */
00203     if (future != TRACK_BIT_HORZ && future != TRACK_BIT_VERT) {
00204       return_cmd_error((flags & DC_NO_RAIL_OVERLAP) ? STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION : STR_ERROR_MUST_REMOVE_SIGNALS_FIRST);
00205     }
00206   }
00207   /* Normally, we may overlap and any combination is valid */
00208   return CommandCost();
00209 }
00210 
00211 
00213 static const TrackBits _valid_tracks_without_foundation[15] = {
00214   TRACK_BIT_ALL,
00215   TRACK_BIT_RIGHT,
00216   TRACK_BIT_UPPER,
00217   TRACK_BIT_X,
00218 
00219   TRACK_BIT_LEFT,
00220   TRACK_BIT_NONE,
00221   TRACK_BIT_Y,
00222   TRACK_BIT_LOWER,
00223 
00224   TRACK_BIT_LOWER,
00225   TRACK_BIT_Y,
00226   TRACK_BIT_NONE,
00227   TRACK_BIT_LEFT,
00228 
00229   TRACK_BIT_X,
00230   TRACK_BIT_UPPER,
00231   TRACK_BIT_RIGHT,
00232 };
00233 
00235 static const TrackBits _valid_tracks_on_leveled_foundation[15] = {
00236   TRACK_BIT_NONE,
00237   TRACK_BIT_LEFT,
00238   TRACK_BIT_LOWER,
00239   TRACK_BIT_Y | TRACK_BIT_LOWER | TRACK_BIT_LEFT,
00240 
00241   TRACK_BIT_RIGHT,
00242   TRACK_BIT_ALL,
00243   TRACK_BIT_X | TRACK_BIT_LOWER | TRACK_BIT_RIGHT,
00244   TRACK_BIT_ALL,
00245 
00246   TRACK_BIT_UPPER,
00247   TRACK_BIT_X | TRACK_BIT_UPPER | TRACK_BIT_LEFT,
00248   TRACK_BIT_ALL,
00249   TRACK_BIT_ALL,
00250 
00251   TRACK_BIT_Y | TRACK_BIT_UPPER | TRACK_BIT_RIGHT,
00252   TRACK_BIT_ALL,
00253   TRACK_BIT_ALL
00254 };
00255 
00263 Foundation GetRailFoundation(Slope tileh, TrackBits bits)
00264 {
00265   if (bits == TRACK_BIT_NONE) return FOUNDATION_NONE;
00266 
00267   if (IsSteepSlope(tileh)) {
00268     /* Test for inclined foundations */
00269     if (bits == TRACK_BIT_X) return FOUNDATION_INCLINED_X;
00270     if (bits == TRACK_BIT_Y) return FOUNDATION_INCLINED_Y;
00271 
00272     /* Get higher track */
00273     Corner highest_corner = GetHighestSlopeCorner(tileh);
00274     TrackBits higher_track = CornerToTrackBits(highest_corner);
00275 
00276     /* Only higher track? */
00277     if (bits == higher_track) return HalftileFoundation(highest_corner);
00278 
00279     /* Overlap with higher track? */
00280     if (TracksOverlap(bits | higher_track)) return FOUNDATION_INVALID;
00281 
00282     /* either lower track or both higher and lower track */
00283     return ((bits & higher_track) != 0 ? FOUNDATION_STEEP_BOTH : FOUNDATION_STEEP_LOWER);
00284   } else {
00285     if ((~_valid_tracks_without_foundation[tileh] & bits) == 0) return FOUNDATION_NONE;
00286 
00287     bool valid_on_leveled = ((~_valid_tracks_on_leveled_foundation[tileh] & bits) == 0);
00288 
00289     Corner track_corner;
00290     switch (bits) {
00291       case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
00292       case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
00293       case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
00294       case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
00295 
00296       case TRACK_BIT_HORZ:
00297         if (tileh == SLOPE_N) return HalftileFoundation(CORNER_N);
00298         if (tileh == SLOPE_S) return HalftileFoundation(CORNER_S);
00299         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00300 
00301       case TRACK_BIT_VERT:
00302         if (tileh == SLOPE_W) return HalftileFoundation(CORNER_W);
00303         if (tileh == SLOPE_E) return HalftileFoundation(CORNER_E);
00304         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00305 
00306       case TRACK_BIT_X:
00307         if (IsSlopeWithOneCornerRaised(tileh)) return FOUNDATION_INCLINED_X;
00308         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00309 
00310       case TRACK_BIT_Y:
00311         if (IsSlopeWithOneCornerRaised(tileh)) return FOUNDATION_INCLINED_Y;
00312         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00313 
00314       default:
00315         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00316     }
00317     /* Single diagonal track */
00318 
00319     /* Track must be at least valid on leveled foundation */
00320     if (!valid_on_leveled) return FOUNDATION_INVALID;
00321 
00322     /* If slope has three raised corners, build leveled foundation */
00323     if (IsSlopeWithThreeCornersRaised(tileh)) return FOUNDATION_LEVELED;
00324 
00325     /* If neighboured corners of track_corner are lowered, build halftile foundation */
00326     if ((tileh & SlopeWithThreeCornersRaised(OppositeCorner(track_corner))) == SlopeWithOneCornerRaised(track_corner)) return HalftileFoundation(track_corner);
00327 
00328     /* else special anti-zig-zag foundation */
00329     return SpecialRailFoundation(track_corner);
00330   }
00331 }
00332 
00333 
00343 static CommandCost CheckRailSlope(Slope tileh, TrackBits rail_bits, TrackBits existing, TileIndex tile)
00344 {
00345   /* don't allow building on the lower side of a coast */
00346   if (GetFloodingBehaviour(tile) != FLOOD_NONE) {
00347     if (!IsSteepSlope(tileh) && ((~_valid_tracks_on_leveled_foundation[tileh] & (rail_bits | existing)) != 0)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
00348   }
00349 
00350   Foundation f_new = GetRailFoundation(tileh, rail_bits | existing);
00351 
00352   /* check track/slope combination */
00353   if ((f_new == FOUNDATION_INVALID) ||
00354       ((f_new != FOUNDATION_NONE) && (!_settings_game.construction.build_on_slopes))) {
00355     return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00356   }
00357 
00358   Foundation f_old = GetRailFoundation(tileh, existing);
00359   return CommandCost(EXPENSES_CONSTRUCTION, f_new != f_old ? _price[PR_BUILD_FOUNDATION] : (Money)0);
00360 }
00361 
00362 /* Validate functions for rail building */
00363 static inline bool ValParamTrackOrientation(Track track)
00364 {
00365   return IsValidTrack(track);
00366 }
00367 
00377 CommandCost CmdBuildSingleRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00378 {
00379   RailType railtype = Extract<RailType, 0, 4>(p1);
00380   Track track = Extract<Track, 0, 3>(p2);
00381   CommandCost cost(EXPENSES_CONSTRUCTION);
00382 
00383   if (!ValParamRailtype(railtype) || !ValParamTrackOrientation(track)) return CMD_ERROR;
00384 
00385   Slope tileh = GetTileSlope(tile, NULL);
00386   TrackBits trackbit = TrackToTrackBits(track);
00387 
00388   switch (GetTileType(tile)) {
00389     case MP_RAILWAY: {
00390       CommandCost ret = CheckTileOwnership(tile);
00391       if (ret.Failed()) return ret;
00392 
00393       if (!IsPlainRail(tile)) return CMD_ERROR;
00394 
00395       if (!IsCompatibleRail(GetRailType(tile), railtype)) return_cmd_error(STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION);
00396 
00397       ret = CheckTrackCombination(tile, trackbit, flags);
00398       if (ret.Succeeded()) ret = EnsureNoTrainOnTrack(tile, track);
00399       if (ret.Failed()) return ret;
00400 
00401       ret = CheckRailSlope(tileh, trackbit, GetTrackBits(tile), tile);
00402       if (ret.Failed()) return ret;
00403       cost.AddCost(ret);
00404 
00405       /* If the rail types don't match, try to convert only if engines of
00406        * the new rail type are not powered on the present rail type and engines of
00407        * the present rail type are powered on the new rail type. */
00408       if (GetRailType(tile) != railtype && !HasPowerOnRail(railtype, GetRailType(tile))) {
00409         if (HasPowerOnRail(GetRailType(tile), railtype)) {
00410           ret = DoCommand(tile, tile, railtype, flags, CMD_CONVERT_RAIL);
00411           if (ret.Failed()) return ret;
00412           cost.AddCost(ret);
00413         } else {
00414           return CMD_ERROR;
00415         }
00416       }
00417 
00418       if (flags & DC_EXEC) {
00419         SetRailGroundType(tile, RAIL_GROUND_BARREN);
00420         SetTrackBits(tile, GetTrackBits(tile) | trackbit);
00421       }
00422       break;
00423     }
00424 
00425     case MP_ROAD: {
00426       /* Level crossings may only be built on these slopes */
00427       if (!HasBit(VALID_LEVEL_CROSSING_SLOPES, tileh)) return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00428 
00429       CommandCost ret = EnsureNoVehicleOnGround(tile);
00430       if (ret.Failed()) return ret;
00431 
00432       if (IsNormalRoad(tile)) {
00433         if (HasRoadWorks(tile)) return_cmd_error(STR_ERROR_ROAD_WORKS_IN_PROGRESS);
00434 
00435         if (GetDisallowedRoadDirections(tile) != DRD_NONE) return_cmd_error(STR_ERROR_CROSSING_ON_ONEWAY_ROAD);
00436 
00437         if (RailNoLevelCrossings(railtype)) return_cmd_error(STR_ERROR_CROSSING_DISALLOWED);
00438 
00439         RoadTypes roadtypes = GetRoadTypes(tile);
00440         RoadBits road = GetRoadBits(tile, ROADTYPE_ROAD);
00441         RoadBits tram = GetRoadBits(tile, ROADTYPE_TRAM);
00442         switch (roadtypes) {
00443           default: break;
00444           case ROADTYPES_TRAM:
00445             /* Tram crossings must always have road. */
00446             if (flags & DC_EXEC) SetRoadOwner(tile, ROADTYPE_ROAD, _current_company);
00447             roadtypes |= ROADTYPES_ROAD;
00448             break;
00449 
00450           case ROADTYPES_ALL:
00451             if (road != tram) return CMD_ERROR;
00452             break;
00453         }
00454 
00455         road |= tram;
00456 
00457         if ((track == TRACK_X && road == ROAD_Y) ||
00458             (track == TRACK_Y && road == ROAD_X)) {
00459           if (flags & DC_EXEC) {
00460             MakeRoadCrossing(tile, GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM), _current_company, (track == TRACK_X ? AXIS_Y : AXIS_X), railtype, roadtypes, GetTownIndex(tile));
00461             UpdateLevelCrossing(tile, false);
00462           }
00463           break;
00464         }
00465       }
00466 
00467       if (IsLevelCrossing(tile) && GetCrossingRailBits(tile) == trackbit) {
00468         return_cmd_error(STR_ERROR_ALREADY_BUILT);
00469       }
00470       /* FALL THROUGH */
00471     }
00472 
00473     default: {
00474       /* Will there be flat water on the lower halftile? */
00475       bool water_ground = IsTileType(tile, MP_WATER) && IsSlopeWithOneCornerRaised(tileh);
00476 
00477       CommandCost ret = CheckRailSlope(tileh, trackbit, TRACK_BIT_NONE, tile);
00478       if (ret.Failed()) return ret;
00479       cost.AddCost(ret);
00480 
00481       ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00482       if (ret.Failed()) return ret;
00483       cost.AddCost(ret);
00484 
00485       if (water_ground) {
00486         cost.AddCost(-_price[PR_CLEAR_WATER]);
00487         cost.AddCost(_price[PR_CLEAR_ROUGH]);
00488       }
00489 
00490       if (flags & DC_EXEC) {
00491         MakeRailNormal(tile, _current_company, trackbit, railtype);
00492         if (water_ground) SetRailGroundType(tile, RAIL_GROUND_WATER);
00493       }
00494       break;
00495     }
00496   }
00497 
00498   if (flags & DC_EXEC) {
00499     MarkTileDirtyByTile(tile);
00500     AddTrackToSignalBuffer(tile, track, _current_company);
00501     YapfNotifyTrackLayoutChange(tile, track);
00502   }
00503 
00504   cost.AddCost(RailBuildCost(railtype));
00505   return cost;
00506 }
00507 
00517 CommandCost CmdRemoveSingleRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00518 {
00519   Track track = Extract<Track, 0, 3>(p2);
00520   CommandCost cost(EXPENSES_CONSTRUCTION);
00521   bool crossing = false;
00522 
00523   if (!ValParamTrackOrientation(track)) return CMD_ERROR;
00524   TrackBits trackbit = TrackToTrackBits(track);
00525 
00526   /* Need to read tile owner now because it may change when the rail is removed
00527    * Also, in case of floods, _current_company != owner
00528    * There may be invalid tiletype even in exec run (when removing long track),
00529    * so do not call GetTileOwner(tile) in any case here */
00530   Owner owner = INVALID_OWNER;
00531 
00532   Train *v = NULL;
00533 
00534   switch (GetTileType(tile)) {
00535     case MP_ROAD: {
00536       if (!IsLevelCrossing(tile) || GetCrossingRailBits(tile) != trackbit) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00537 
00538       if (_current_company != OWNER_WATER) {
00539         CommandCost ret = CheckTileOwnership(tile);
00540         if (ret.Failed()) return ret;
00541       }
00542 
00543       if (!(flags & DC_BANKRUPT)) {
00544         CommandCost ret = EnsureNoVehicleOnGround(tile);
00545         if (ret.Failed()) return ret;
00546       }
00547 
00548       cost.AddCost(RailClearCost(GetRailType(tile)));
00549 
00550       if (flags & DC_EXEC) {
00551         if (HasReservedTracks(tile, trackbit)) {
00552           v = GetTrainForReservation(tile, track);
00553           if (v != NULL) FreeTrainTrackReservation(v);
00554         }
00555         owner = GetTileOwner(tile);
00556         MakeRoadNormal(tile, GetCrossingRoadBits(tile), GetRoadTypes(tile), GetTownIndex(tile), GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM));
00557         DeleteNewGRFInspectWindow(GSF_RAILTYPES, tile);
00558       }
00559       break;
00560     }
00561 
00562     case MP_RAILWAY: {
00563       TrackBits present;
00564       /* There are no rails present at depots. */
00565       if (!IsPlainRail(tile)) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00566 
00567       if (_current_company != OWNER_WATER) {
00568         CommandCost ret = CheckTileOwnership(tile);
00569         if (ret.Failed()) return ret;
00570       }
00571 
00572       CommandCost ret = EnsureNoTrainOnTrack(tile, track);
00573       if (ret.Failed()) return ret;
00574 
00575       present = GetTrackBits(tile);
00576       if ((present & trackbit) == 0) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00577       if (present == (TRACK_BIT_X | TRACK_BIT_Y)) crossing = true;
00578 
00579       cost.AddCost(RailClearCost(GetRailType(tile)));
00580 
00581       /* Charge extra to remove signals on the track, if they are there */
00582       if (HasSignalOnTrack(tile, track)) {
00583         /* If track has an exit signal on it dissalow removal. */
00584 // 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.
00585 //       Removing the dependency or the being dependant upon flag would work equally well here ...
00586         if (IsPresignalExit(tile, track)) {
00587           return_cmd_error(STR_ERROR_MUST_REMOVE_EXIT_SIGNALS_FIRST);
00588         } else {
00589           CheckRemoveSignal(tile, track);
00590           cost.AddCost(DoCommand(tile, track, 0, flags, CMD_REMOVE_SIGNALS));
00591         }
00592       }
00593 
00594       if (flags & DC_EXEC) {
00595         if (HasReservedTracks(tile, trackbit)) {
00596           v = GetTrainForReservation(tile, track);
00597           if (v != NULL) FreeTrainTrackReservation(v);
00598         }
00599         owner = GetTileOwner(tile);
00600         present ^= trackbit;
00601         if (present == 0) {
00602           Slope tileh = GetTileSlope(tile, NULL);
00603           /* If there is flat water on the lower halftile, convert the tile to shore so the water remains */
00604           if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh)) {
00605             MakeShore(tile);
00606           } else {
00607             DoClearSquare(tile);
00608           }
00609           DeleteNewGRFInspectWindow(GSF_RAILTYPES, tile);
00610         } else {
00611           SetTrackBits(tile, present);
00612           SetTrackReservation(tile, GetRailReservationTrackBits(tile) & present);
00613         }
00614       }
00615       break;
00616     }
00617 
00618     default: return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00619   }
00620 
00621   if (flags & DC_EXEC) {
00622     /* if we got that far, 'owner' variable is set correctly */
00623     assert(Company::IsValidID(owner));
00624 
00625     MarkTileDirtyByTile(tile);
00626     if (crossing) {
00627       /* crossing is set when only TRACK_BIT_X and TRACK_BIT_Y are set. As we
00628        * are removing one of these pieces, we'll need to update signals for
00629        * both directions explicitly, as after the track is removed it won't
00630        * 'connect' with the other piece. */
00631       AddTrackToSignalBuffer(tile, TRACK_X, owner);
00632       AddTrackToSignalBuffer(tile, TRACK_Y, owner);
00633       YapfNotifyTrackLayoutChange(tile, TRACK_X);
00634       YapfNotifyTrackLayoutChange(tile, TRACK_Y);
00635     } else {
00636       AddTrackToSignalBuffer(tile, track, owner);
00637       YapfNotifyTrackLayoutChange(tile, track);
00638     }
00639 
00640     if (v != NULL) TryPathReserve(v, true);
00641   }
00642 
00643   return cost;
00644 }
00645 
00646 
00654 bool FloodHalftile(TileIndex t)
00655 {
00656   assert(IsPlainRailTile(t));
00657 
00658   bool flooded = false;
00659   if (GetRailGroundType(t) == RAIL_GROUND_WATER) return flooded;
00660 
00661   Slope tileh = GetTileSlope(t, NULL);
00662   TrackBits rail_bits = GetTrackBits(t);
00663 
00664   if (IsSlopeWithOneCornerRaised(tileh)) {
00665     TrackBits lower_track = CornerToTrackBits(OppositeCorner(GetHighestSlopeCorner(tileh)));
00666 
00667     TrackBits to_remove = lower_track & rail_bits;
00668     if (to_remove != 0) {
00669       Backup<CompanyByte> cur_company(_current_company, OWNER_WATER, FILE_LINE);
00670       flooded = DoCommand(t, 0, FIND_FIRST_BIT(to_remove), DC_EXEC, CMD_REMOVE_SINGLE_RAIL).Succeeded();
00671       cur_company.Restore();
00672       if (!flooded) return flooded; // not yet floodable
00673       rail_bits = rail_bits & ~to_remove;
00674       if (rail_bits == 0) {
00675         MakeShore(t);
00676         MarkTileDirtyByTile(t);
00677         return flooded;
00678       }
00679     }
00680 
00681     if (IsNonContinuousFoundation(GetRailFoundation(tileh, rail_bits))) {
00682       flooded = true;
00683       SetRailGroundType(t, RAIL_GROUND_WATER);
00684       MarkTileDirtyByTile(t);
00685     }
00686   } else {
00687     /* Make shore on steep slopes and 'three-corners-raised'-slopes. */
00688     if (ApplyFoundationToSlope(GetRailFoundation(tileh, rail_bits), &tileh) == 0) {
00689       if (IsSteepSlope(tileh) || IsSlopeWithThreeCornersRaised(tileh)) {
00690         flooded = true;
00691         SetRailGroundType(t, RAIL_GROUND_WATER);
00692         MarkTileDirtyByTile(t);
00693       }
00694     }
00695   }
00696   return flooded;
00697 }
00698 
00699 static const TileIndexDiffC _trackdelta[] = {
00700   { -1,  0 }, {  0,  1 }, { -1,  0 }, {  0,  1 }, {  1,  0 }, {  0,  1 },
00701   {  0,  0 },
00702   {  0,  0 },
00703   {  1,  0 }, {  0, -1 }, {  0, -1 }, {  1,  0 }, {  0, -1 }, { -1,  0 },
00704   {  0,  0 },
00705   {  0,  0 }
00706 };
00707 
00708 
00709 static CommandCost ValidateAutoDrag(Trackdir *trackdir, TileIndex start, TileIndex end)
00710 {
00711   int x = TileX(start);
00712   int y = TileY(start);
00713   int ex = TileX(end);
00714   int ey = TileY(end);
00715 
00716   if (!ValParamTrackOrientation(TrackdirToTrack(*trackdir))) return CMD_ERROR;
00717 
00718   /* calculate delta x,y from start to end tile */
00719   int dx = ex - x;
00720   int dy = ey - y;
00721 
00722   /* calculate delta x,y for the first direction */
00723   int trdx = _trackdelta[*trackdir].x;
00724   int trdy = _trackdelta[*trackdir].y;
00725 
00726   if (!IsDiagonalTrackdir(*trackdir)) {
00727     trdx += _trackdelta[*trackdir ^ 1].x;
00728     trdy += _trackdelta[*trackdir ^ 1].y;
00729   }
00730 
00731   /* validate the direction */
00732   while ((trdx <= 0 && dx > 0) ||
00733       (trdx >= 0 && dx < 0) ||
00734       (trdy <= 0 && dy > 0) ||
00735       (trdy >= 0 && dy < 0)) {
00736     if (!HasBit(*trackdir, 3)) { // first direction is invalid, try the other
00737       SetBit(*trackdir, 3); // reverse the direction
00738       trdx = -trdx;
00739       trdy = -trdy;
00740     } else { // other direction is invalid too, invalid drag
00741       return CMD_ERROR;
00742     }
00743   }
00744 
00745   /* (for diagonal tracks, this is already made sure of by above test), but:
00746    * for non-diagonal tracks, check if the start and end tile are on 1 line */
00747   if (!IsDiagonalTrackdir(*trackdir)) {
00748     trdx = _trackdelta[*trackdir].x;
00749     trdy = _trackdelta[*trackdir].y;
00750     if (abs(dx) != abs(dy) && abs(dx) + abs(trdy) != abs(dy) + abs(trdx)) return CMD_ERROR;
00751   }
00752 
00753   return CommandCost();
00754 }
00755 
00769 static CommandCost CmdRailTrackHelper(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00770 {
00771   CommandCost total_cost(EXPENSES_CONSTRUCTION);
00772   Track track = Extract<Track, 4, 3>(p2);
00773   bool remove = HasBit(p2, 7);
00774   RailType railtype = Extract<RailType, 0, 4>(p2);
00775 
00776   if (!ValParamRailtype(railtype) || !ValParamTrackOrientation(track)) return CMD_ERROR;
00777   if (p1 >= MapSize()) return CMD_ERROR;
00778   TileIndex end_tile = p1;
00779   Trackdir trackdir = TrackToTrackdir(track);
00780 
00781   CommandCost ret = ValidateAutoDrag(&trackdir, tile, end_tile);
00782   if (ret.Failed()) return ret;
00783 
00784   if (flags & DC_EXEC) SndPlayTileFx(SND_20_SPLAT_2, tile);
00785 
00786   bool had_success = false;
00787   CommandCost last_error = CMD_ERROR;
00788   for (;;) {
00789     CommandCost ret = DoCommand(tile, railtype, TrackdirToTrack(trackdir), flags, remove ? CMD_REMOVE_SINGLE_RAIL : CMD_BUILD_SINGLE_RAIL);
00790 
00791     if (ret.Failed()) {
00792       last_error = ret;
00793       if (last_error.GetErrorMessage() != STR_ERROR_ALREADY_BUILT && !remove) {
00794         if (HasBit(p2, 8)) return last_error;
00795         break;
00796       }
00797 
00798       /* Ownership errors are more important. */
00799       if (last_error.GetErrorMessage() == STR_ERROR_OWNED_BY && remove) break;
00800     } else {
00801       had_success = true;
00802       total_cost.AddCost(ret);
00803     }
00804 
00805     if (tile == end_tile) break;
00806 
00807     tile += ToTileIndexDiff(_trackdelta[trackdir]);
00808 
00809     /* toggle railbit for the non-diagonal tracks */
00810     if (!IsDiagonalTrackdir(trackdir)) ToggleBit(trackdir, 0);
00811   }
00812 
00813   if (had_success) return total_cost;
00814   return last_error;
00815 }
00816 
00831 CommandCost CmdBuildRailroadTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00832 {
00833   return CmdRailTrackHelper(tile, flags, p1, ClrBit(p2, 7), text);
00834 }
00835 
00850 CommandCost CmdRemoveRailroadTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00851 {
00852   return CmdRailTrackHelper(tile, flags, p1, SetBit(p2, 7), text);
00853 }
00854 
00867 CommandCost CmdBuildTrainDepot(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00868 {
00869   /* check railtype and valid direction for depot (0 through 3), 4 in total */
00870   RailType railtype = Extract<RailType, 0, 4>(p1);
00871   if (!ValParamRailtype(railtype)) return CMD_ERROR;
00872 
00873   Slope tileh = GetTileSlope(tile, NULL);
00874 
00875   DiagDirection dir = Extract<DiagDirection, 0, 2>(p2);
00876 
00877   /* Prohibit construction if
00878    * The tile is non-flat AND
00879    * 1) build-on-slopes is disabled
00880    * 2) the tile is steep i.e. spans two height levels
00881    * 3) the exit points in the wrong direction
00882    */
00883 
00884   if (tileh != SLOPE_FLAT && (
00885         !_settings_game.construction.build_on_slopes ||
00886         IsSteepSlope(tileh) ||
00887         !CanBuildDepotByTileh(dir, tileh)
00888       )) {
00889     return_cmd_error(STR_ERROR_FLAT_LAND_REQUIRED);
00890   }
00891 
00892   CommandCost cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00893   if (cost.Failed()) return cost;
00894 
00895   if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00896 
00897   if (!Depot::CanAllocateItem()) return CMD_ERROR;
00898 
00899   if (flags & DC_EXEC) {
00900     Depot *d = new Depot(tile);
00901     d->build_date = _date;
00902 
00903     MakeRailDepot(tile, _current_company, d->index, dir, railtype);
00904     MarkTileDirtyByTile(tile);
00905     MakeDefaultName(d);
00906 
00907     AddSideToSignalBuffer(tile, INVALID_DIAGDIR, _current_company);
00908     YapfNotifyTrackLayoutChange(tile, DiagDirToDiagTrack(dir));
00909   }
00910 
00911   cost.AddCost(_price[PR_BUILD_DEPOT_TRAIN]);
00912   cost.AddCost(RailBuildCost(railtype));
00913   return cost;
00914 }
00915 
00936 CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00937 {
00938   Track track = Extract<Track, 0, 3>(p1);
00939   bool ctrl_pressed = HasBit(p1, 3); // was the CTRL button pressed
00940   SignalVariant sigvar = (ctrl_pressed ^ HasBit(p1, 4)) ? SIG_SEMAPHORE : SIG_ELECTRIC; // the signal variant of the new signal
00941   SignalType sigtype = Extract<SignalType, 5, 3>(p1); // the signal type of the new signal
00942   bool convert_signal = HasBit(p1, 8); // convert button pressed
00943   uint num_dir_cycle = GB(p1, 15, 2);
00944   uint which_signals = GB(p1, 9, 6);
00945 
00946   if (sigtype > SIGTYPE_LAST) return CMD_ERROR;
00947 
00948   /* You can only build signals on plain rail tiles or tunnel/bridges, and the selected track must exist */
00949   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
00950     if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return CMD_ERROR;
00951     CommandCost ret = EnsureNoTrainOnTrack(GetOtherTunnelBridgeEnd(tile), track);
00952     if (ret.Failed()) return ret;
00953   } else if (!ValParamTrackOrientation(track) || !IsPlainRailTile(tile) || !HasTrack(tile, track)) {
00954       return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
00955   }
00956   CommandCost ret = EnsureNoTrainOnTrack(tile, track);
00957   if (ret.Failed()) return ret;
00958 
00959   /* Protect against invalid signal copying */
00960   if (p2 != 0 && (p2 & SignalOnTrack(track)) == 0) return CMD_ERROR;
00961 
00962   ret = CheckTileOwnership(tile);
00963 
00964   if (ret.Failed()) return ret;
00965 
00966   CommandCost cost;
00967   /* Handle signals simulation on tunnel/bridge. */
00968   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
00969     TileIndex tile_exit = GetOtherTunnelBridgeEnd(tile);
00970     cost = CommandCost();
00971     if (!HasWormholeSignals(tile)) { // Toggle signal zero costs.
00972       if (p2 != 12) cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] * ((GetTunnelBridgeLength(tile, tile_exit) + 4) >> 2)); // minimal 1
00973     }
00974     if (flags & DC_EXEC) {
00975       if (p2 == 0 && HasWormholeSignals(tile)){ // Toggle signal if allready signals present.
00976         if (IsTunnelBridgeEntrance (tile)) {
00977           ClrBitTunnelBridgeSignal(tile);
00978           ClrBitTunnelBridgeExit(tile_exit);
00979           SetBitTunnelBridgeExit(tile);
00980           SetBitTunnelBridgeSignal(tile_exit);
00981         } else {
00982           ClrBitTunnelBridgeSignal(tile_exit);
00983           ClrBitTunnelBridgeExit(tile);
00984           SetBitTunnelBridgeExit(tile_exit);
00985           SetBitTunnelBridgeSignal(tile);
00986         }     
00987       } else{
00988         /* Create one direction tunnel/bridge if required. */
00989         if (p2 == 0) {
00990           SetBitTunnelBridgeSignal(tile);
00991           SetBitTunnelBridgeExit(tile_exit);
00992         } else if (p2 == 4 || p2 == 8) {
00993           DiagDirection tbdir = GetTunnelBridgeDirection(tile);
00994           /* If signal only on one side build accoringly one-way tunnel/bridge. */
00995           if ((p2 == 8 && (tbdir == DIAGDIR_NE || tbdir == DIAGDIR_SE)) ||
00996             (p2 == 4 && (tbdir == DIAGDIR_SW || tbdir == DIAGDIR_NW))) {
00997             SetBitTunnelBridgeSignal(tile);
00998             SetBitTunnelBridgeExit(tile_exit);
00999           } else {
01000             SetBitTunnelBridgeSignal(tile_exit);
01001             SetBitTunnelBridgeExit(tile);
01002           }
01003         }     
01004       }
01005       MarkTileDirtyByTile(tile);
01006       MarkTileDirtyByTile(tile_exit);
01007       AddSideToSignalBuffer(tile, INVALID_DIAGDIR, _current_company);
01008       YapfNotifyTrackLayoutChange(tile, track);
01009     }
01010     return cost;
01011   }
01012 
01013   {
01014     /* See if this is a valid track combination for signals, (ie, no overlap) */
01015     TrackBits trackbits = GetTrackBits(tile);
01016     if (KillFirstBit(trackbits) != TRACK_BIT_NONE && // More than one track present
01017         trackbits != TRACK_BIT_HORZ &&
01018         trackbits != TRACK_BIT_VERT) {
01019       return_cmd_error(STR_ERROR_NO_SUITABLE_RAILROAD_TRACK);
01020     }
01021   }
01022 
01023   /* In case we don't want to change an existing signal, return without error. */
01024   if (HasBit(p1, 17) && HasSignalOnTrack(tile, track)) return CommandCost();
01025 
01026   /* you can not convert a signal if no signal is on track */
01027   if (convert_signal && !HasSignalOnTrack(tile, track)) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
01028 
01029   if (!HasSignalOnTrack(tile, track)) {
01030     /* build new signals */
01031     cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS]);
01032   } else {
01033     if (p2 != 0 && sigvar != GetSignalVariant(tile, track)) {
01034       /* convert signals <-> semaphores */
01035       cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]);
01036 
01037     } else if (convert_signal) {
01038       /* convert button pressed */
01039       if (ctrl_pressed || GetSignalVariant(tile, track) != sigvar) {
01040         /* convert electric <-> semaphore */
01041         cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]);
01042       } else {
01043         /* it is free to change signal type: normal-pre-exit-combo */
01044         cost = CommandCost();
01045       }
01046 
01047     } else {
01048       /* it is free to change orientation/pre-exit-combo signals */
01049       cost = CommandCost();
01050     }
01051   }
01052 
01053   if (flags & DC_EXEC) {
01054     Train *v = NULL;
01055     /* The new/changed signal could block our path. As this can lead to
01056      * stale reservations, we clear the path reservation here and try
01057      * to redo it later on. */
01058     if (HasReservedTracks(tile, TrackToTrackBits(track))) {
01059       v = GetTrainForReservation(tile, track);
01060       if (v != NULL) FreeTrainTrackReservation(v);
01061     }
01062 
01063     if (!HasSignals(tile)) {
01064       /* there are no signals at all on this tile yet */
01065       SetHasSignals(tile, true);
01066       SetSignalStates(tile, 0xF); // all signals are on
01067       SetPresentSignals(tile, 0); // no signals built by default
01068       SetSignalType(tile, track, sigtype);
01069       SetSignalVariant(tile, track, sigvar);
01070     }
01071 
01072     if (p2 == 0) {
01073       if (!HasSignalOnTrack(tile, track)) {
01074         /* build new signals */
01075         SetPresentSignals(tile, GetPresentSignals(tile) | (IsPbsSignal(sigtype) ? KillFirstBit(SignalOnTrack(track)) : SignalOnTrack(track)));
01076         SetSignalType(tile, track, sigtype);
01077         SetSignalVariant(tile, track, sigvar);
01078         while (num_dir_cycle-- > 0) CycleSignalSide(tile, track);
01079       } else {
01080         if (convert_signal) {
01081           /* convert signal button pressed */
01082           if (ctrl_pressed) {
01083             /* toggle the pressent signal variant: SIG_ELECTRIC <-> SIG_SEMAPHORE */
01084             SetSignalVariant(tile, track, (GetSignalVariant(tile, track) == SIG_ELECTRIC) ? SIG_SEMAPHORE : SIG_ELECTRIC);
01085             /* Query current signal type so the check for PBS signals below works. */
01086             sigtype = GetSignalType(tile, track);
01087           } else {
01088             /* convert the present signal to the chosen type and variant */
01089             if (IsPresignalProgrammable(tile, track)) {
01090               FreeSignalProgram(SignalReference(tile, track));
01091             } else if(IsSpeedSignal(tile, track)) {
01092               FreeSignalSpeed(SignalReference(tile, track));
01093             }
01094             SetSignalType(tile, track, sigtype);
01095             SetSignalVariant(tile, track, sigvar);
01096             if (IsPbsSignal(sigtype) && (GetPresentSignals(tile) & SignalOnTrack(track)) == SignalOnTrack(track)) {
01097               SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | KillFirstBit(SignalOnTrack(track)));
01098             }
01099           }
01100 
01101         } else if (ctrl_pressed) {
01102           /* cycle through signal types */
01103           sigtype = (SignalType)(GetSignalType(tile, track));
01104           if(IsProgrammableSignal(sigtype)) {
01105             FreeSignalProgram(SignalReference(tile, track));
01106           } else if(IsSpeedSignal(sigtype)) {
01107             FreeSignalSpeed(SignalReference(tile, track));
01108           }
01109           sigtype = NextSignalType(sigtype, which_signals);
01110           SetSignalType(tile, track, sigtype);
01111           if (IsPbsSignal(sigtype) && (GetPresentSignals(tile) & SignalOnTrack(track)) == SignalOnTrack(track)) {
01112             SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | KillFirstBit(SignalOnTrack(track)));
01113           }
01114         } else {
01115           /* cycle the signal side: both -> left -> right -> both -> ... */
01116           CycleSignalSide(tile, track);
01117           /* Query current signal type so the check for PBS signals below works. */
01118           sigtype = GetSignalType(tile, track);
01119         }
01120       }
01121     } else {
01122       /* If CmdBuildManySignals is called with copying signals, just copy the
01123        * direction of the first signal given as parameter by CmdBuildManySignals */
01124       SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | (p2 & SignalOnTrack(track)));
01125       SetSignalVariant(tile, track, sigvar);
01126       if(IsPresignalProgrammable(tile, track)) {
01127         FreeSignalProgram(SignalReference(tile, track));
01128       } else if(IsSpeedSignal(tile, track)) {
01129         FreeSignalSpeed(SignalReference(tile, track));
01130       }
01131       SetSignalType(tile, track, sigtype);
01132     }
01133 
01134     if (IsPbsSignal(sigtype)) {
01135       /* PBS signals should show red unless they are on a reservation. */
01136       uint mask = GetPresentSignals(tile) & SignalOnTrack(track);
01137       SetSignalStates(tile, (GetSignalStates(tile) & ~mask) | ((HasBit(GetRailReservationTrackBits(tile), track) ? UINT_MAX : 0) & mask));
01138     }
01139     MarkTileDirtyByTile(tile);
01140     AddTrackToSignalBuffer(tile, track, _current_company);
01141     YapfNotifyTrackLayoutChange(tile, track);
01142     if (v != NULL) {
01143       /* Extend the train's path if it's not stopped or loading, or not at a safe position. */
01144       if (!(((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) || v->current_order.IsType(OT_LOADING)) ||
01145           !IsSafeWaitingPosition(v, v->tile, v->GetVehicleTrackdir(), true, _settings_game.pf.forbid_90_deg)) {
01146         TryPathReserve(v, true);
01147       }
01148     }
01149   }
01150 
01151   return cost;
01152 }
01153 
01154 static bool CheckSignalAutoFill(TileIndex &tile, Trackdir &trackdir, int &signal_ctr, bool remove)
01155 {
01156   tile = AddTileIndexDiffCWrap(tile, _trackdelta[trackdir]);
01157   if (tile == INVALID_TILE) return false;
01158 
01159   /* Check for track bits on the new tile */
01160   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0));
01161 
01162   if (TracksOverlap(TrackdirBitsToTrackBits(trackdirbits))) return false;
01163   trackdirbits &= TrackdirReachesTrackdirs(trackdir);
01164 
01165   /* No track bits, must stop */
01166   if (trackdirbits == TRACKDIR_BIT_NONE) return false;
01167 
01168   /* Get the first track dir */
01169   trackdir = RemoveFirstTrackdir(&trackdirbits);
01170 
01171   /* Any left? It's a junction so we stop */
01172   if (trackdirbits != TRACKDIR_BIT_NONE) return false;
01173 
01174   switch (GetTileType(tile)) {
01175     case MP_RAILWAY:
01176       if (IsRailDepot(tile)) return false;
01177       if (!remove && HasSignalOnTrack(tile, TrackdirToTrack(trackdir))) return false;
01178       signal_ctr++;
01179       if (IsDiagonalTrackdir(trackdir)) {
01180         signal_ctr++;
01181         /* Ensure signal_ctr even so X and Y pieces get signals */
01182         ClrBit(signal_ctr, 0);
01183       }
01184       return true;
01185 
01186     case MP_ROAD:
01187       if (!IsLevelCrossing(tile)) return false;
01188       signal_ctr += 2;
01189       return true;
01190 
01191     case MP_TUNNELBRIDGE: {
01192       if (!remove && HasWormholeSignals(tile)) return false;
01193       TileIndex orig_tile = tile; // backup old value
01194 
01195       if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return false;
01196       if (GetTunnelBridgeDirection(tile) != TrackdirToExitdir(trackdir)) return false;
01197 
01198       /* Skip to end of tunnel or bridge
01199        * note that tile is a parameter by reference, so it must be updated */
01200       tile = GetOtherTunnelBridgeEnd(tile);
01201 
01202       signal_ctr += (GetTunnelBridgeLength(orig_tile, tile) + 2) * 2;
01203       return true;
01204     }
01205 
01206     default: return false;
01207   }
01208 }
01209 
01226 static CommandCost CmdSignalTrackHelper(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01227 {
01228   CommandCost total_cost(EXPENSES_CONSTRUCTION);
01229   TileIndex start_tile = tile;
01230 
01231   Track track = Extract<Track, 0, 3>(p2);
01232   bool mode = HasBit(p2, 3);
01233   bool semaphores = HasBit(p2, 4);
01234   bool remove = HasBit(p2, 5);
01235   bool autofill = HasBit(p2, 6);
01236   byte signal_density = GB(p2, 24, 8);
01237 
01238   if (p1 >= MapSize() || !ValParamTrackOrientation(track)) return CMD_ERROR;
01239   TileIndex end_tile = p1;
01240   if (signal_density == 0 || signal_density > 20) return CMD_ERROR;
01241 
01242   if (!IsPlainRailTile(tile)) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
01243 
01244   /* for vertical/horizontal tracks, double the given signals density
01245    * since the original amount will be too dense (shorter tracks) */
01246   signal_density *= 2;
01247 
01248   Trackdir trackdir = TrackToTrackdir(track);
01249   CommandCost ret = ValidateAutoDrag(&trackdir, tile, end_tile);
01250   if (ret.Failed()) return ret;
01251 
01252   track = TrackdirToTrack(trackdir); // trackdir might have changed, keep track in sync
01253   Trackdir start_trackdir = trackdir;
01254 
01255   /* Must start on a valid track to be able to avoid loops */
01256   if (!HasTrack(tile, track)) return CMD_ERROR;
01257 
01258   SignalType sigtype = (SignalType)GB(p2, 7, 3);
01259   if (sigtype > SIGTYPE_LAST) return CMD_ERROR;
01260 
01261   byte signals;
01262   /* copy the signal-style of the first rail-piece if existing */
01263   if (HasSignalOnTrack(tile, track)) {
01264     signals = GetPresentSignals(tile) & SignalOnTrack(track);
01265     assert(signals != 0);
01266 
01267     /* copy signal/semaphores style (independent of CTRL) */
01268     semaphores = GetSignalVariant(tile, track) != SIG_ELECTRIC;
01269 
01270     sigtype = GetSignalType(tile, track);
01271     /* Don't but copy entry or exit-signal type */
01272     if (sigtype == SIGTYPE_ENTRY || sigtype == SIGTYPE_EXIT) sigtype = SIGTYPE_NORMAL;
01273   } else { // no signals exist, drag a two-way signal stretch
01274     signals = IsPbsSignal(sigtype) ? SignalAlongTrackdir(trackdir) : SignalOnTrack(track);
01275   }
01276 
01277   byte signal_dir = 0;
01278   if (signals & SignalAlongTrackdir(trackdir))   SetBit(signal_dir, 0);
01279   if (signals & SignalAgainstTrackdir(trackdir)) SetBit(signal_dir, 1);
01280 
01281   /* signal_ctr         - amount of tiles already processed
01282    * signals_density    - setting to put signal on every Nth tile (double space on |, -- tracks)
01283    **********
01284    * trackdir   - trackdir to build with autorail
01285    * semaphores - semaphores or signals
01286    * signals    - is there a signal/semaphore on the first tile, copy its style (two-way/single-way)
01287    *              and convert all others to semaphore/signal
01288    * remove     - 1 remove signals, 0 build signals */
01289   int signal_ctr = 0;
01290   CommandCost last_error = CMD_ERROR;
01291   bool had_success = false;
01292   for (;;) {
01293     /* only build/remove signals with the specified density */
01294     if ((remove && autofill) || signal_ctr % signal_density == 0 || IsTileType(tile, MP_TUNNELBRIDGE)) {
01295       uint32 p1 = GB(TrackdirToTrack(trackdir), 0, 3);
01296       SB(p1, 3, 1, mode);
01297       SB(p1, 4, 1, semaphores);
01298       SB(p1, 5, 3, sigtype);
01299       if (!remove && signal_ctr == 0) SetBit(p1, 17);
01300 
01301       /* Pick the correct orientation for the track direction */
01302       signals = 0;
01303       if (HasBit(signal_dir, 0)) signals |= SignalAlongTrackdir(trackdir);
01304       if (HasBit(signal_dir, 1)) signals |= SignalAgainstTrackdir(trackdir);
01305 
01306       CommandCost ret = DoCommand(tile, p1, signals, flags, remove ? CMD_REMOVE_SIGNALS : CMD_BUILD_SIGNALS);
01307 
01308       /* Be user-friendly and try placing signals as much as possible */
01309       if (ret.Succeeded()) {
01310         had_success = true;
01311         if (IsTileType(tile, MP_TUNNELBRIDGE)) {
01312           if ((!autofill && GetTunnelBridgeDirection(tile) == TrackdirToExitdir(trackdir)) ||
01313               (autofill && GetTunnelBridgeDirection(tile) != TrackdirToExitdir(trackdir))) {
01314             total_cost.AddCost(ret);
01315           }
01316         } else {
01317           total_cost.AddCost(ret);
01318         }
01319       } else {
01320         /* The "No railway" error is the least important one. */
01321         if (ret.GetErrorMessage() != STR_ERROR_THERE_IS_NO_RAILROAD_TRACK ||
01322             last_error.GetErrorMessage() == INVALID_STRING_ID) {
01323           last_error = ret;
01324         }
01325       }
01326     }
01327 
01328     if (autofill) {
01329       if (!CheckSignalAutoFill(tile, trackdir, signal_ctr, remove)) break;
01330 
01331       /* Prevent possible loops */
01332       if (tile == start_tile && trackdir == start_trackdir) break;
01333     } else {
01334       if (tile == end_tile) break;
01335 
01336       tile += ToTileIndexDiff(_trackdelta[trackdir]);
01337       signal_ctr++;
01338 
01339       /* toggle railbit for the non-diagonal tracks (|, -- tracks) */
01340       if (IsDiagonalTrackdir(trackdir)) {
01341         signal_ctr++;
01342       } else {
01343         ToggleBit(trackdir, 0);
01344       }
01345     }
01346   }
01347 
01348   return had_success ? total_cost : last_error;
01349 }
01350 
01369 CommandCost CmdBuildSignalTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01370 {
01371   return CmdSignalTrackHelper(tile, flags, p1, p2, text);
01372 }
01373 
01386 CommandCost CmdRemoveSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01387 {
01388   Track track = Extract<Track, 0, 3>(p1);
01389   Money cost = _price[PR_CLEAR_SIGNALS];
01390 
01391   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
01392     TileIndex end = GetOtherTunnelBridgeEnd(tile);
01393     if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
01394     if (!HasWormholeSignals(tile)) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
01395 
01396     cost *= ((GetTunnelBridgeLength(tile, end) + 4) >> 2);
01397 
01398     CommandCost ret = EnsureNoTrainOnTrack(GetOtherTunnelBridgeEnd(tile), track);
01399     if (ret.Failed()) return ret;
01400   } else {
01401     if (!ValParamTrackOrientation(track) || !IsPlainRailTile(tile) || !HasTrack(tile, track)) {
01402       return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
01403     }
01404     if (!HasSignalOnTrack(tile, track)) {
01405       return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
01406     }
01407     CommandCost ret = EnsureNoTrainOnTrack(tile, track);
01408     if (ret.Failed()) return ret;
01409   }
01410 
01411   /* Only water can remove signals from anyone */
01412   if (_current_company != OWNER_WATER) {
01413     CommandCost ret = CheckTileOwnership(tile);
01414     if (ret.Failed()) return ret;
01415   }
01416 
01417   /* Do it? */
01418   if (flags & DC_EXEC) {
01419 
01420     if (HasWormholeSignals(tile)) { // Handle tunnel/bridge signals.
01421       TileIndex end = GetOtherTunnelBridgeEnd(tile);
01422       ClrBitTunnelBridgeExit(tile);
01423       ClrBitTunnelBridgeExit(end);
01424       ClrBitTunnelBridgeSignal(tile);
01425       ClrBitTunnelBridgeSignal(end);
01426       _m[tile].m2 = 0;
01427       _m[end].m2 = 0;
01428       MarkTileDirtyByTile(tile);
01429       MarkTileDirtyByTile(end);
01430       return CommandCost(EXPENSES_CONSTRUCTION, cost);
01431     }
01432 
01433     Train *v = NULL;
01434     if (HasReservedTracks(tile, TrackToTrackBits(track))) {
01435       v = GetTrainForReservation(tile, track);
01436     } else if (IsPbsSignal(GetSignalType(tile, track))) {
01437       /* PBS signal, might be the end of a path reservation. */
01438       Trackdir td = TrackToTrackdir(track);
01439       for (int i = 0; v == NULL && i < 2; i++, td = ReverseTrackdir(td)) {
01440         /* Only test the active signal side. */
01441         if (!HasSignalOnTrackdir(tile, ReverseTrackdir(td))) continue;
01442         TileIndex next = TileAddByDiagDir(tile, TrackdirToExitdir(td));
01443         TrackBits tracks = TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(td));
01444         if (HasReservedTracks(next, tracks)) {
01445           v = GetTrainForReservation(next, TrackBitsToTrack(GetReservedTrackbits(next) & tracks));
01446         }
01447       }
01448     }
01449     
01450     CheckRemoveSignal(tile, track);
01451     SetPresentSignals(tile, GetPresentSignals(tile) & ~SignalOnTrack(track));
01452 
01453     /* removed last signal from tile? */
01454     if (GetPresentSignals(tile) == 0) {
01455       SetSignalStates(tile, 0);
01456       SetHasSignals(tile, false);
01457       SetSignalVariant(tile, INVALID_TRACK, SIG_ELECTRIC); // remove any possible semaphores
01458     }
01459 
01460     AddTrackToSignalBuffer(tile, track, GetTileOwner(tile));
01461     YapfNotifyTrackLayoutChange(tile, track);
01462     if (v != NULL) TryPathReserve(v, false);
01463 
01464     MarkTileDirtyByTile(tile);
01465   }
01466 
01467   return CommandCost(EXPENSES_CONSTRUCTION, cost);
01468 }
01469 
01488 CommandCost CmdRemoveSignalTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01489 {
01490   return CmdSignalTrackHelper(tile, flags, p1, SetBit(p2, 5), text); // bit 5 is remove bit
01491 }
01492 
01494 static Vehicle *UpdateTrainPowerProc(Vehicle *v, void *data)
01495 {
01496   if (v->type != VEH_TRAIN) return NULL;
01497 
01498   TrainList *affected_trains = static_cast<TrainList*>(data);
01499   affected_trains->Include(Train::From(v)->First());
01500 
01501   return NULL;
01502 }
01503 
01514 CommandCost CmdConvertRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01515 {
01516   RailType totype = Extract<RailType, 0, 4>(p2);
01517 
01518   if (!ValParamRailtype(totype)) return CMD_ERROR;
01519   if (p1 >= MapSize()) return CMD_ERROR;
01520 
01521   TrainList affected_trains;
01522 
01523   CommandCost cost(EXPENSES_CONSTRUCTION);
01524   CommandCost error = CommandCost(STR_ERROR_NO_SUITABLE_RAILROAD_TRACK); // by default, there is no track to convert.
01525   TileArea ta(tile, p1);
01526   TILE_AREA_LOOP(tile, ta) {
01527     TileType tt = GetTileType(tile);
01528 
01529     /* Check if there is any track on tile */
01530     switch (tt) {
01531       case MP_RAILWAY:
01532         break;
01533       case MP_STATION:
01534         if (!HasStationRail(tile)) continue;
01535         break;
01536       case MP_ROAD:
01537         if (!IsLevelCrossing(tile)) continue;
01538         if (RailNoLevelCrossings(totype)) {
01539           error.MakeError(STR_ERROR_CROSSING_DISALLOWED);
01540           continue;
01541         }
01542         break;
01543       case MP_TUNNELBRIDGE:
01544         if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) continue;
01545         break;
01546       default: continue;
01547     }
01548 
01549     /* Original railtype we are converting from */
01550     RailType type = GetRailType(tile);
01551 
01552     /* Converting to the same type or converting 'hidden' elrail -> rail */
01553     if (type == totype || (_settings_game.vehicle.disable_elrails && totype == RAILTYPE_RAIL && type == RAILTYPE_ELECTRIC)) continue;
01554 
01555     /* Trying to convert other's rail */
01556     CommandCost ret = CheckTileOwnership(tile);
01557     if (ret.Failed()) {
01558       error = ret;
01559       continue;
01560     }
01561 
01562     SmallVector<Train *, 2> vehicles_affected;
01563 
01564     /* Vehicle on the tile when not converting Rail <-> ElRail
01565      * Tunnels and bridges have special check later */
01566     if (tt != MP_TUNNELBRIDGE) {
01567       if (!IsCompatibleRail(type, totype)) {
01568         CommandCost ret = EnsureNoVehicleOnGround(tile);
01569         if (ret.Failed()) {
01570           error = ret;
01571           continue;
01572         }
01573       }
01574       if (flags & DC_EXEC) { // we can safely convert, too
01575         TrackBits reserved = GetReservedTrackbits(tile);
01576         Track     track;
01577         while ((track = RemoveFirstTrack(&reserved)) != INVALID_TRACK) {
01578           Train *v = GetTrainForReservation(tile, track);
01579           if (v != NULL && !HasPowerOnRail(v->railtype, totype)) {
01580             /* No power on new rail type, reroute. */
01581             FreeTrainTrackReservation(v);
01582             *vehicles_affected.Append() = v;
01583           }
01584         }
01585 
01586         SetRailType(tile, totype);
01587         MarkTileDirtyByTile(tile);
01588         /* update power of train on this tile */
01589         FindVehicleOnPos(tile, &affected_trains, &UpdateTrainPowerProc);
01590       }
01591     }
01592 
01593     switch (tt) {
01594       case MP_RAILWAY:
01595         switch (GetRailTileType(tile)) {
01596           case RAIL_TILE_DEPOT:
01597             if (flags & DC_EXEC) {
01598               /* notify YAPF about the track layout change */
01599               YapfNotifyTrackLayoutChange(tile, GetRailDepotTrack(tile));
01600 
01601               /* Update build vehicle window related to this depot */
01602               InvalidateWindowData(WC_VEHICLE_DEPOT, tile);
01603               InvalidateWindowData(WC_BUILD_VEHICLE, tile);
01604             }
01605             cost.AddCost(RailConvertCost(type, totype));
01606             break;
01607 
01608           default: // RAIL_TILE_NORMAL, RAIL_TILE_SIGNALS
01609             if (flags & DC_EXEC) {
01610               /* notify YAPF about the track layout change */
01611               TrackBits tracks = GetTrackBits(tile);
01612               while (tracks != TRACK_BIT_NONE) {
01613                 YapfNotifyTrackLayoutChange(tile, RemoveFirstTrack(&tracks));
01614               }
01615             }
01616             cost.AddCost(RailConvertCost(type, totype) * CountBits(GetTrackBits(tile)));
01617             break;
01618         }
01619         break;
01620 
01621       case MP_TUNNELBRIDGE: {
01622         TileIndex endtile = GetOtherTunnelBridgeEnd(tile);
01623 
01624         /* If both ends of tunnel/bridge are in the range, do not try to convert twice -
01625          * it would cause assert because of different test and exec runs */
01626         if (endtile < tile && TileX(endtile) >= TileX(ta.tile) && TileX(endtile) < TileX(ta.tile) + ta.w &&
01627             TileY(endtile) >= TileY(ta.tile) && TileY(endtile) < TileY(ta.tile) + ta.h) continue;
01628 
01629         /* When not coverting rail <-> el. rail, any vehicle cannot be in tunnel/bridge */
01630         if (!IsCompatibleRail(GetRailType(tile), totype)) {
01631           CommandCost ret = TunnelBridgeIsFree(tile, endtile);
01632           if (ret.Failed()) {
01633             error = ret;
01634             continue;
01635           }
01636         }
01637 
01638         if (flags & DC_EXEC) {
01639           Track track = DiagDirToDiagTrack(GetTunnelBridgeDirection(tile));
01640           if (HasTunnelBridgeReservation(tile)) {
01641             Train *v = GetTrainForReservation(tile, track);
01642             if (v != NULL && !HasPowerOnRail(v->railtype, totype)) {
01643               /* No power on new rail type, reroute. */
01644               FreeTrainTrackReservation(v);
01645               *vehicles_affected.Append() = v;
01646             }
01647           }
01648           SetRailType(tile, totype);
01649           SetRailType(endtile, totype);
01650 
01651           FindVehicleOnPos(tile, &affected_trains, &UpdateTrainPowerProc);
01652           FindVehicleOnPos(endtile, &affected_trains, &UpdateTrainPowerProc);
01653 
01654           YapfNotifyTrackLayoutChange(tile, track);
01655           YapfNotifyTrackLayoutChange(endtile, track);
01656 
01657           MarkTileDirtyByTile(tile);
01658           MarkTileDirtyByTile(endtile);
01659 
01660           if (IsBridge(tile)) {
01661             TileIndexDiff delta = TileOffsByDiagDir(GetTunnelBridgeDirection(tile));
01662             TileIndex t = tile + delta;
01663             for (; t != endtile; t += delta) MarkTileDirtyByTile(t); // TODO encapsulate this into a function
01664           }
01665         }
01666 
01667         cost.AddCost((GetTunnelBridgeLength(tile, endtile) + 2) * RailConvertCost(type, totype));
01668         break;
01669       }
01670 
01671       default: // MP_STATION, MP_ROAD
01672         if (flags & DC_EXEC) {
01673           Track track = ((tt == MP_STATION) ? GetRailStationTrack(tile) : GetCrossingRailTrack(tile));
01674           YapfNotifyTrackLayoutChange(tile, track);
01675         }
01676 
01677         cost.AddCost(RailConvertCost(type, totype));
01678         break;
01679     }
01680 
01681     for (uint i = 0; i < vehicles_affected.Length(); ++i) {
01682       TryPathReserve(vehicles_affected[i], true);
01683     }
01684   }
01685 
01686   if (flags & DC_EXEC) {
01687     /* Railtype changed, update trains as when entering different track */
01688     for (Train **v = affected_trains.Begin(); v != affected_trains.End(); v++) {
01689       (*v)->RailtypeChanged();
01690     }
01691   }
01692 
01693   return (cost.GetCost() == 0) ? error : cost;
01694 }
01695 
01696 static CommandCost RemoveTrainDepot(TileIndex tile, DoCommandFlag flags)
01697 {
01698   if (_current_company != OWNER_WATER) {
01699     CommandCost ret = CheckTileOwnership(tile);
01700     if (ret.Failed()) return ret;
01701   }
01702 
01703   CommandCost ret = EnsureNoVehicleOnGround(tile);
01704   if (ret.Failed()) return ret;
01705 
01706   if (flags & DC_EXEC) {
01707     /* read variables before the depot is removed */
01708     DiagDirection dir = GetRailDepotDirection(tile);
01709     Owner owner = GetTileOwner(tile);
01710     Train *v = NULL;
01711 
01712     if (HasDepotReservation(tile)) {
01713       v = GetTrainForReservation(tile, DiagDirToDiagTrack(dir));
01714       if (v != NULL) FreeTrainTrackReservation(v);
01715     }
01716 
01717     delete Depot::GetByTile(tile);
01718     DoClearSquare(tile);
01719     AddSideToSignalBuffer(tile, dir, owner);
01720     YapfNotifyTrackLayoutChange(tile, DiagDirToDiagTrack(dir));
01721     if (v != NULL) TryPathReserve(v, true);
01722   }
01723 
01724   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_DEPOT_TRAIN]);
01725 }
01726 
01727 static CommandCost ClearTile_Track(TileIndex tile, DoCommandFlag flags)
01728 {
01729   CommandCost cost(EXPENSES_CONSTRUCTION);
01730 
01731   if (flags & DC_AUTO) {
01732     if (!IsTileOwner(tile, _current_company)) {
01733       return_cmd_error(STR_ERROR_AREA_IS_OWNED_BY_ANOTHER);
01734     }
01735 
01736     if (IsPlainRail(tile)) {
01737       return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
01738     } else {
01739       return_cmd_error(STR_ERROR_BUILDING_MUST_BE_DEMOLISHED);
01740     }
01741   }
01742 
01743   switch (GetRailTileType(tile)) {
01744     case RAIL_TILE_SIGNALS:
01745       if (flags & DC_EXEC) CheckRemoveSignalsFromTile(tile);
01746 
01747     case RAIL_TILE_NORMAL: {
01748       Slope tileh = GetTileSlope(tile, NULL);
01749       /* Is there flat water on the lower halftile that gets cleared expensively? */
01750       bool water_ground = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh));
01751 
01752       TrackBits tracks = GetTrackBits(tile);
01753       while (tracks != TRACK_BIT_NONE) {
01754         Track track = RemoveFirstTrack(&tracks);
01755         CommandCost ret = DoCommand(tile, 0, track, flags, CMD_REMOVE_SINGLE_RAIL);
01756         if (ret.Failed()) return ret;
01757         cost.AddCost(ret);
01758       }
01759 
01760       /* when bankrupting, don't make water dirty, there could be a ship on lower halftile */
01761       if (water_ground && !(flags & DC_BANKRUPT)) {
01762         CommandCost ret = EnsureNoVehicleOnGround(tile);
01763         if (ret.Failed()) return ret;
01764 
01765         /* The track was removed, and left a coast tile. Now also clear the water. */
01766         if (flags & DC_EXEC) DoClearSquare(tile);
01767         cost.AddCost(_price[PR_CLEAR_WATER]);
01768       }
01769 
01770       return cost;
01771     }
01772 
01773     case RAIL_TILE_DEPOT:
01774       return RemoveTrainDepot(tile, flags);
01775 
01776     default:
01777       return CMD_ERROR;
01778   }
01779 }
01780 
01785 static uint GetSaveSlopeZ(uint x, uint y, Track track)
01786 {
01787   switch (track) {
01788     case TRACK_UPPER: x &= ~0xF; y &= ~0xF; break;
01789     case TRACK_LOWER: x |=  0xF; y |=  0xF; break;
01790     case TRACK_LEFT:  x |=  0xF; y &= ~0xF; break;
01791     case TRACK_RIGHT: x &= ~0xF; y |=  0xF; break;
01792     default: break;
01793   }
01794   return GetSlopeZ(x, y);
01795 }
01796 
01797 static void DrawSingleSignal(TileIndex tile, Track track, byte condition, uint image, uint pos)
01798 {
01799   bool side = (_settings_game.vehicle.road_side != 0) && _settings_game.construction.signal_side;
01800   static const Point SignalPositions[2][12] = {
01801     { // Signals on the left side
01802     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01803       { 8,  5}, {14,  1}, { 1, 14}, { 9, 11}, { 1,  0}, { 3, 10},
01804     /*  LOWER     LOWER     X         X         Y         Y     */
01805       {11,  4}, {14, 14}, {11,  3}, { 4, 13}, { 3,  4}, {11, 13}
01806     }, { // Signals on the right side
01807     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01808       {14,  1}, {12, 10}, { 4,  6}, { 1, 14}, {10,  4}, { 0,  1},
01809     /*  LOWER     LOWER     X         X         Y         Y     */
01810       {14, 14}, { 5, 12}, {11, 13}, { 4,  3}, {13,  4}, { 3, 11}
01811     }
01812   };
01813 
01814   uint x = TileX(tile) * TILE_SIZE + SignalPositions[side][pos].x;
01815   uint y = TileY(tile) * TILE_SIZE + SignalPositions[side][pos].y;
01816 
01817   SpriteID sprite;
01818 
01819   SignalType type       = GetSignalType(tile, track);
01820   SignalVariant variant = GetSignalVariant(tile, track);
01821 
01822   if (type == SIGTYPE_NORMAL && variant == SIG_ELECTRIC) {
01823     /* Normal electric signals are picked from original sprites. */
01824     sprite = SPR_ORIGINAL_SIGNALS_BASE + image + condition;
01825 // TODO: change drawing of speed and progsigs to the "other signals" method when the sprites are added to openttd.grf.
01826   } else if (type == SIGTYPE_PROG && variant == SIG_ELECTRIC) {
01827     /* Speed electric signals are picked from speedsignals.gf sprites. */
01828     sprite = (SPR_PROGSIGNAL_BASE + 16) + image + condition;
01829   } else if (type == SIGTYPE_PROG && variant == SIG_SEMAPHORE) {
01830     /* Speed semaphore signals are picked from speedsignals.gf sprites. */
01831     sprite = SPR_PROGSIGNAL_BASE + image + condition;
01832   } else if (type == SIGTYPE_SPEED && variant == SIG_ELECTRIC) {
01833     /* Speed electric signals are picked from speedsignals.gf sprites. */
01834     sprite = (SPR_SPEEDSIGNAL_BASE + 16) + image + condition;
01835   } else if (type == SIGTYPE_SPEED && variant == SIG_SEMAPHORE) {
01836     /* Speed semaphore signals are picked from speedsignals.gf sprites. */
01837     sprite = SPR_SPEEDSIGNAL_BASE + image + condition;
01838   } else {
01839     /* All other signals are picked from add on sprites. */
01840     sprite = SPR_SIGNALS_BASE + (type - 1) * 16 + variant * 64 + image + condition + (IsSignalSpritePBS(type) ? 64 : 0);
01841   }
01842 
01843   AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
01844 }
01845 
01846 static uint32 _drawtile_track_palette;
01847 
01848 
01849 static void DrawTrackFence_NW(const TileInfo *ti, SpriteID base_image)
01850 {
01851   RailFenceOffset rfo = RFO_FLAT_X;
01852   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SW : RFO_SLOPE_NE;
01853   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01854     ti->x, ti->y + 1, 16, 1, 4, ti->z);
01855 }
01856 
01857 static void DrawTrackFence_SE(const TileInfo *ti, SpriteID base_image)
01858 {
01859   RailFenceOffset rfo = RFO_FLAT_X;
01860   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SW : RFO_SLOPE_NE;
01861   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01862     ti->x, ti->y + TILE_SIZE - 1, 16, 1, 4, ti->z);
01863 }
01864 
01865 static void DrawTrackFence_NW_SE(const TileInfo *ti, SpriteID base_image)
01866 {
01867   DrawTrackFence_NW(ti, base_image);
01868   DrawTrackFence_SE(ti, base_image);
01869 }
01870 
01871 static void DrawTrackFence_NE(const TileInfo *ti, SpriteID base_image)
01872 {
01873   RailFenceOffset rfo = RFO_FLAT_Y;
01874   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SE : RFO_SLOPE_NW;
01875   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01876     ti->x + 1, ti->y, 1, 16, 4, ti->z);
01877 }
01878 
01879 static void DrawTrackFence_SW(const TileInfo *ti, SpriteID base_image)
01880 {
01881   RailFenceOffset rfo = RFO_FLAT_Y;
01882   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SE : RFO_SLOPE_NW;
01883   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01884     ti->x + TILE_SIZE - 1, ti->y, 1, 16, 4, ti->z);
01885 }
01886 
01887 static void DrawTrackFence_NE_SW(const TileInfo *ti, SpriteID base_image)
01888 {
01889   DrawTrackFence_NE(ti, base_image);
01890   DrawTrackFence_SW(ti, base_image);
01891 }
01892 
01896 static void DrawTrackFence_NS_1(const TileInfo *ti, SpriteID base_image)
01897 {
01898   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_W);
01899   AddSortableSpriteToDraw(base_image + RFO_FLAT_VERT, _drawtile_track_palette,
01900     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01901 }
01902 
01906 static void DrawTrackFence_NS_2(const TileInfo *ti, SpriteID base_image)
01907 {
01908   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_E);
01909   AddSortableSpriteToDraw(base_image + RFO_FLAT_VERT, _drawtile_track_palette,
01910     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01911 }
01912 
01916 static void DrawTrackFence_WE_1(const TileInfo *ti, SpriteID base_image)
01917 {
01918   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_N);
01919   AddSortableSpriteToDraw(base_image + RFO_FLAT_HORZ, _drawtile_track_palette,
01920     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01921 }
01922 
01926 static void DrawTrackFence_WE_2(const TileInfo *ti, SpriteID base_image)
01927 {
01928   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_S);
01929   AddSortableSpriteToDraw(base_image + RFO_FLAT_HORZ, _drawtile_track_palette,
01930     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01931 }
01932 
01933 
01934 static void DrawTrackDetails(const TileInfo *ti, const RailtypeInfo *rti)
01935 {
01936   /* Base sprite for track fences.
01937    * Note: Halftile slopes only have fences on the upper part. */
01938   SpriteID base_image = GetCustomRailSprite(rti, ti->tile, RTSG_FENCES, IsHalftileSlope(ti->tileh) ? TCX_UPPER_HALFTILE : TCX_NORMAL);
01939   if (base_image == 0) base_image = SPR_TRACK_FENCE_FLAT_X;
01940 
01941   switch (GetRailGroundType(ti->tile)) {
01942     case RAIL_GROUND_FENCE_NW:     DrawTrackFence_NW(ti, base_image);    break;
01943     case RAIL_GROUND_FENCE_SE:     DrawTrackFence_SE(ti, base_image);    break;
01944     case RAIL_GROUND_FENCE_SENW:   DrawTrackFence_NW_SE(ti, base_image); break;
01945     case RAIL_GROUND_FENCE_NE:     DrawTrackFence_NE(ti, base_image);    break;
01946     case RAIL_GROUND_FENCE_SW:     DrawTrackFence_SW(ti, base_image);    break;
01947     case RAIL_GROUND_FENCE_NESW:   DrawTrackFence_NE_SW(ti, base_image); break;
01948     case RAIL_GROUND_FENCE_VERT1:  DrawTrackFence_NS_1(ti, base_image);  break;
01949     case RAIL_GROUND_FENCE_VERT2:  DrawTrackFence_NS_2(ti, base_image);  break;
01950     case RAIL_GROUND_FENCE_HORIZ1: DrawTrackFence_WE_1(ti, base_image);  break;
01951     case RAIL_GROUND_FENCE_HORIZ2: DrawTrackFence_WE_2(ti, base_image);  break;
01952     case RAIL_GROUND_WATER: {
01953       Corner track_corner;
01954       if (IsHalftileSlope(ti->tileh)) {
01955         /* Steep slope or one-corner-raised slope with halftile foundation */
01956         track_corner = GetHalftileSlopeCorner(ti->tileh);
01957       } else {
01958         /* Three-corner-raised slope */
01959         track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
01960       }
01961       switch (track_corner) {
01962         case CORNER_W: DrawTrackFence_NS_1(ti, base_image); break;
01963         case CORNER_S: DrawTrackFence_WE_2(ti, base_image); break;
01964         case CORNER_E: DrawTrackFence_NS_2(ti, base_image); break;
01965         case CORNER_N: DrawTrackFence_WE_1(ti, base_image); break;
01966         default: NOT_REACHED();
01967       }
01968       break;
01969     }
01970     default: break;
01971   }
01972 }
01973 
01974 /* SubSprite for drawing the track halftile of 'three-corners-raised'-sloped rail sprites. */
01975 static const int INF = 1000; // big number compared to tilesprite size
01976 static const SubSprite _halftile_sub_sprite[4] = {
01977   { -INF    , -INF  , 32 - 33, INF     }, // CORNER_W, clip 33 pixels from right
01978   { -INF    ,  0 + 7, INF    , INF     }, // CORNER_S, clip 7 pixels from top
01979   { -31 + 33, -INF  , INF    , INF     }, // CORNER_E, clip 33 pixels from left
01980   { -INF    , -INF  , INF    , 30 - 23 }  // CORNER_N, clip 23 pixels from bottom
01981 };
01982 
01983 static inline void DrawTrackSprite(SpriteID sprite, PaletteID pal, const TileInfo *ti, Slope s)
01984 {
01985   DrawGroundSprite(sprite, pal, NULL, 0, (ti->tileh & s) ? -8 : 0);
01986 }
01987 
01988 static void DrawTrackBitsOverlay(TileInfo *ti, TrackBits track, const RailtypeInfo *rti)
01989 {
01990   RailGroundType rgt = GetRailGroundType(ti->tile);
01991   Foundation f = GetRailFoundation(ti->tileh, track);
01992   Corner halftile_corner = CORNER_INVALID;
01993 
01994   if (IsNonContinuousFoundation(f)) {
01995     /* Save halftile corner */
01996     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
01997     /* Draw lower part first */
01998     track &= ~CornerToTrackBits(halftile_corner);
01999     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
02000   }
02001 
02002   DrawFoundation(ti, f);
02003   /* DrawFoundation modifies ti */
02004 
02005   /* Draw ground */
02006   if (rgt == RAIL_GROUND_WATER) {
02007     if (track != TRACK_BIT_NONE || IsSteepSlope(ti->tileh)) {
02008       /* three-corner-raised slope or steep slope with track on upper part */
02009       DrawShoreTile(ti->tileh);
02010     } else {
02011       /* single-corner-raised slope with track on upper part */
02012       DrawGroundSprite(SPR_FLAT_WATER_TILE, PAL_NONE);
02013     }
02014   } else {
02015     SpriteID image;
02016 
02017     switch (rgt) {
02018       case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
02019       case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOW_DESERT_TILE; break;
02020       default:                     image = SPR_FLAT_GRASS_TILE; break;
02021     }
02022 
02023     image += SlopeToSpriteOffset(ti->tileh);
02024 
02025     DrawGroundSprite(image, PAL_NONE);
02026   }
02027 
02028   SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
02029   SpriteID ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND);
02030   TrackBits pbs = _settings_client.gui.show_track_reservation ? GetRailReservationTrackBits(ti->tile) : TRACK_BIT_NONE;
02031 
02032   if (track == TRACK_BIT_NONE) {
02033     /* Half-tile foundation, no track here? */
02034   } else if (ti->tileh == SLOPE_NW && track == TRACK_BIT_Y) {
02035     DrawGroundSprite(ground + RTO_SLOPE_NW, PAL_NONE);
02036     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 9, PALETTE_CRASH);
02037   } else if (ti->tileh == SLOPE_NE && track == TRACK_BIT_X) {
02038     DrawGroundSprite(ground + RTO_SLOPE_NE, PAL_NONE);
02039     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 6, PALETTE_CRASH);
02040   } else if (ti->tileh == SLOPE_SE && track == TRACK_BIT_Y) {
02041     DrawGroundSprite(ground + RTO_SLOPE_SE, PAL_NONE);
02042     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 7, PALETTE_CRASH);
02043   } else if (ti->tileh == SLOPE_SW && track == TRACK_BIT_X) {
02044     DrawGroundSprite(ground + RTO_SLOPE_SW, PAL_NONE);
02045     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 8, PALETTE_CRASH);
02046   } else {
02047     switch (track) {
02048       /* Draw single ground sprite when not overlapping. No track overlay
02049        * is necessary for these sprites. */
02050       case TRACK_BIT_X:     DrawGroundSprite(ground + RTO_X, PAL_NONE); break;
02051       case TRACK_BIT_Y:     DrawGroundSprite(ground + RTO_Y, PAL_NONE); break;
02052       case TRACK_BIT_UPPER: DrawTrackSprite(ground + RTO_N, PAL_NONE, ti, SLOPE_N); break;
02053       case TRACK_BIT_LOWER: DrawTrackSprite(ground + RTO_S, PAL_NONE, ti, SLOPE_S); break;
02054       case TRACK_BIT_RIGHT: DrawTrackSprite(ground + RTO_E, PAL_NONE, ti, SLOPE_E); break;
02055       case TRACK_BIT_LEFT:  DrawTrackSprite(ground + RTO_W, PAL_NONE, ti, SLOPE_W); break;
02056       case TRACK_BIT_CROSS: DrawGroundSprite(ground + RTO_CROSSING_XY, PAL_NONE); break;
02057       case TRACK_BIT_HORZ:  DrawTrackSprite(ground + RTO_N, PAL_NONE, ti, SLOPE_N);
02058                             DrawTrackSprite(ground + RTO_S, PAL_NONE, ti, SLOPE_S); break;
02059       case TRACK_BIT_VERT:  DrawTrackSprite(ground + RTO_E, PAL_NONE, ti, SLOPE_E);
02060                             DrawTrackSprite(ground + RTO_W, PAL_NONE, ti, SLOPE_W); break;
02061 
02062       default:
02063         /* We're drawing a junction tile */
02064         if ((track & TRACK_BIT_3WAY_NE) == 0) {
02065           DrawGroundSprite(ground + RTO_JUNCTION_SW, PAL_NONE);
02066         } else if ((track & TRACK_BIT_3WAY_SW) == 0) {
02067           DrawGroundSprite(ground + RTO_JUNCTION_NE, PAL_NONE);
02068         } else if ((track & TRACK_BIT_3WAY_NW) == 0) {
02069           DrawGroundSprite(ground + RTO_JUNCTION_SE, PAL_NONE);
02070         } else if ((track & TRACK_BIT_3WAY_SE) == 0) {
02071           DrawGroundSprite(ground + RTO_JUNCTION_NW, PAL_NONE);
02072         } else {
02073           DrawGroundSprite(ground + RTO_JUNCTION_NSEW, PAL_NONE);
02074         }
02075 
02076         /* Mask out PBS bits as we shall draw them afterwards anyway. */
02077         track &= ~pbs;
02078 
02079         /* Draw regular track bits */
02080         if (track & TRACK_BIT_X)     DrawGroundSprite(overlay + RTO_X, PAL_NONE);
02081         if (track & TRACK_BIT_Y)     DrawGroundSprite(overlay + RTO_Y, PAL_NONE);
02082         if (track & TRACK_BIT_UPPER) DrawGroundSprite(overlay + RTO_N, PAL_NONE);
02083         if (track & TRACK_BIT_LOWER) DrawGroundSprite(overlay + RTO_S, PAL_NONE);
02084         if (track & TRACK_BIT_RIGHT) DrawGroundSprite(overlay + RTO_E, PAL_NONE);
02085         if (track & TRACK_BIT_LEFT)  DrawGroundSprite(overlay + RTO_W, PAL_NONE);
02086     }
02087 
02088     /* Draw reserved track bits */
02089     if (pbs & TRACK_BIT_X)     DrawGroundSprite(overlay + RTO_X, PALETTE_CRASH);
02090     if (pbs & TRACK_BIT_Y)     DrawGroundSprite(overlay + RTO_Y, PALETTE_CRASH);
02091     if (pbs & TRACK_BIT_UPPER) DrawTrackSprite(overlay + RTO_N, PALETTE_CRASH, ti, SLOPE_N);
02092     if (pbs & TRACK_BIT_LOWER) DrawTrackSprite(overlay + RTO_S, PALETTE_CRASH, ti, SLOPE_S);
02093     if (pbs & TRACK_BIT_RIGHT) DrawTrackSprite(overlay + RTO_E, PALETTE_CRASH, ti, SLOPE_E);
02094     if (pbs & TRACK_BIT_LEFT)  DrawTrackSprite(overlay + RTO_W, PALETTE_CRASH, ti, SLOPE_W);
02095   }
02096 
02097   if (IsValidCorner(halftile_corner)) {
02098     DrawFoundation(ti, HalftileFoundation(halftile_corner));
02099     overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY, TCX_UPPER_HALFTILE);
02100     ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND, TCX_UPPER_HALFTILE);
02101 
02102     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
02103     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
02104 
02105     SpriteID image;
02106     switch (rgt) {
02107       case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
02108       case RAIL_GROUND_ICE_DESERT:
02109       case RAIL_GROUND_HALF_SNOW:  image = SPR_FLAT_SNOW_DESERT_TILE; break;
02110       default:                     image = SPR_FLAT_GRASS_TILE; break;
02111     }
02112 
02113     image += SlopeToSpriteOffset(fake_slope);
02114 
02115     DrawGroundSprite(image, PAL_NONE, &(_halftile_sub_sprite[halftile_corner]));
02116 
02117     track = CornerToTrackBits(halftile_corner);
02118 
02119     int offset;
02120     switch (track) {
02121       default: NOT_REACHED();
02122       case TRACK_BIT_UPPER: offset = RTO_N; break;
02123       case TRACK_BIT_LOWER: offset = RTO_S; break;
02124       case TRACK_BIT_RIGHT: offset = RTO_E; break;
02125       case TRACK_BIT_LEFT:  offset = RTO_W; break;
02126     }
02127 
02128     DrawTrackSprite(ground + offset, PAL_NONE, ti, fake_slope);
02129     if (_settings_client.gui.show_track_reservation && HasReservedTracks(ti->tile, track)) {
02130       DrawTrackSprite(overlay + offset, PALETTE_CRASH, ti, fake_slope);
02131     }
02132   }
02133 }
02134 
02140 static void DrawTrackBits(TileInfo *ti, TrackBits track)
02141 {
02142   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
02143 
02144   if (rti->UsesOverlay()) {
02145     DrawTrackBitsOverlay(ti, track, rti);
02146     return;
02147   }
02148 
02149   RailGroundType rgt = GetRailGroundType(ti->tile);
02150   Foundation f = GetRailFoundation(ti->tileh, track);
02151   Corner halftile_corner = CORNER_INVALID;
02152 
02153   if (IsNonContinuousFoundation(f)) {
02154     /* Save halftile corner */
02155     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
02156     /* Draw lower part first */
02157     track &= ~CornerToTrackBits(halftile_corner);
02158     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
02159   }
02160 
02161   DrawFoundation(ti, f);
02162   /* DrawFoundation modifies ti */
02163 
02164   SpriteID image;
02165   PaletteID pal = PAL_NONE;
02166   const SubSprite *sub = NULL;
02167   bool junction = false;
02168 
02169   /* Select the sprite to use. */
02170   if (track == 0) {
02171     /* Clear ground (only track on halftile foundation) */
02172     if (rgt == RAIL_GROUND_WATER) {
02173       if (IsSteepSlope(ti->tileh)) {
02174         DrawShoreTile(ti->tileh);
02175         image = 0;
02176       } else {
02177         image = SPR_FLAT_WATER_TILE;
02178       }
02179     } else {
02180       switch (rgt) {
02181         case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
02182         case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOW_DESERT_TILE; break;
02183         default:                     image = SPR_FLAT_GRASS_TILE; break;
02184       }
02185       image += SlopeToSpriteOffset(ti->tileh);
02186     }
02187   } else {
02188     if (ti->tileh != SLOPE_FLAT) {
02189       /* track on non-flat ground */
02190       image = _track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.track_y;
02191     } else {
02192       /* track on flat ground */
02193       (image = rti->base_sprites.track_y, track == TRACK_BIT_Y) ||
02194       (image++,                           track == TRACK_BIT_X) ||
02195       (image++,                           track == TRACK_BIT_UPPER) ||
02196       (image++,                           track == TRACK_BIT_LOWER) ||
02197       (image++,                           track == TRACK_BIT_RIGHT) ||
02198       (image++,                           track == TRACK_BIT_LEFT) ||
02199       (image++,                           track == TRACK_BIT_CROSS) ||
02200 
02201       (image = rti->base_sprites.track_ns, track == TRACK_BIT_HORZ) ||
02202       (image++,                            track == TRACK_BIT_VERT) ||
02203 
02204       (junction = true, false) ||
02205       (image = rti->base_sprites.ground, (track & TRACK_BIT_3WAY_NE) == 0) ||
02206       (image++,                          (track & TRACK_BIT_3WAY_SW) == 0) ||
02207       (image++,                          (track & TRACK_BIT_3WAY_NW) == 0) ||
02208       (image++,                          (track & TRACK_BIT_3WAY_SE) == 0) ||
02209       (image++, true);
02210     }
02211 
02212     switch (rgt) {
02213       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
02214       case RAIL_GROUND_ICE_DESERT: image += rti->snow_offset;  break;
02215       case RAIL_GROUND_WATER: {
02216         /* three-corner-raised slope */
02217         DrawShoreTile(ti->tileh);
02218         Corner track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
02219         sub = &(_halftile_sub_sprite[track_corner]);
02220         break;
02221       }
02222       default: break;
02223     }
02224   }
02225 
02226   if (image != 0) DrawGroundSprite(image, pal, sub);
02227 
02228   /* Draw track pieces individually for junction tiles */
02229   if (junction) {
02230     if (track & TRACK_BIT_X)     DrawGroundSprite(rti->base_sprites.single_x, PAL_NONE);
02231     if (track & TRACK_BIT_Y)     DrawGroundSprite(rti->base_sprites.single_y, PAL_NONE);
02232     if (track & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PAL_NONE);
02233     if (track & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PAL_NONE);
02234     if (track & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PAL_NONE);
02235     if (track & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PAL_NONE);
02236   }
02237 
02238   /* PBS debugging, draw reserved tracks darker */
02239   if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation) {
02240     /* Get reservation, but mask track on halftile slope */
02241     TrackBits pbs = GetRailReservationTrackBits(ti->tile) & track;
02242     if (pbs & TRACK_BIT_X) {
02243       if (ti->tileh == SLOPE_FLAT || ti->tileh == SLOPE_ELEVATED) {
02244         DrawGroundSprite(rti->base_sprites.single_x, PALETTE_CRASH);
02245       } else {
02246         DrawGroundSprite(_track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.single_sloped - 20, PALETTE_CRASH);
02247       }
02248     }
02249     if (pbs & TRACK_BIT_Y) {
02250       if (ti->tileh == SLOPE_FLAT || ti->tileh == SLOPE_ELEVATED) {
02251         DrawGroundSprite(rti->base_sprites.single_y, PALETTE_CRASH);
02252       } else {
02253         DrawGroundSprite(_track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.single_sloped - 20, PALETTE_CRASH);
02254       }
02255     }
02256     if (pbs & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_N ? -(int)TILE_HEIGHT : 0);
02257     if (pbs & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_S ? -(int)TILE_HEIGHT : 0);
02258     if (pbs & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_W ? -(int)TILE_HEIGHT : 0);
02259     if (pbs & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_E ? -(int)TILE_HEIGHT : 0);
02260   }
02261 
02262   if (IsValidCorner(halftile_corner)) {
02263     DrawFoundation(ti, HalftileFoundation(halftile_corner));
02264 
02265     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
02266     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
02267     image = _track_sloped_sprites[fake_slope - 1] + rti->base_sprites.track_y;
02268     pal = PAL_NONE;
02269     switch (rgt) {
02270       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
02271       case RAIL_GROUND_ICE_DESERT:
02272       case RAIL_GROUND_HALF_SNOW:  image += rti->snow_offset;  break; // higher part has snow in this case too
02273       default: break;
02274     }
02275     DrawGroundSprite(image, pal, &(_halftile_sub_sprite[halftile_corner]));
02276 
02277     if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasReservedTracks(ti->tile, CornerToTrackBits(halftile_corner))) {
02278       static const byte _corner_to_track_sprite[] = {3, 1, 2, 0};
02279       DrawGroundSprite(_corner_to_track_sprite[halftile_corner] + rti->base_sprites.single_n, PALETTE_CRASH, NULL, 0, -(int)TILE_HEIGHT);
02280     }
02281   }
02282 }
02283 
02291 enum SignalOffsets {
02292   SIGNAL_TO_SOUTHWEST =  0,
02293   SIGNAL_TO_NORTHEAST =  2,
02294   SIGNAL_TO_SOUTHEAST =  4,
02295   SIGNAL_TO_NORTHWEST =  6,
02296   SIGNAL_TO_EAST      =  8,
02297   SIGNAL_TO_WEST      = 10,
02298   SIGNAL_TO_SOUTH     = 12,
02299   SIGNAL_TO_NORTH     = 14,
02300 };
02301 
02302 static void DrawSignals(TileIndex tile, TrackBits rails)
02303 {
02304 #define MAYBE_DRAW_SIGNAL(x, y, z, t) if (IsSignalPresent(tile, x)) DrawSingleSignal(tile, t, GetSingleSignalState(tile, x), y, z)
02305 
02306   if (!(rails & TRACK_BIT_Y)) {
02307     if (!(rails & TRACK_BIT_X)) {
02308       if (rails & TRACK_BIT_LEFT) {
02309         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTH, 0, TRACK_LEFT);
02310         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTH, 1, TRACK_LEFT);
02311       }
02312       if (rails & TRACK_BIT_RIGHT) {
02313         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_NORTH, 2, TRACK_RIGHT);
02314         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_SOUTH, 3, TRACK_RIGHT);
02315       }
02316       if (rails & TRACK_BIT_UPPER) {
02317         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_WEST, 4, TRACK_UPPER);
02318         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_EAST, 5, TRACK_UPPER);
02319       }
02320       if (rails & TRACK_BIT_LOWER) {
02321         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_WEST, 6, TRACK_LOWER);
02322         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_EAST, 7, TRACK_LOWER);
02323       }
02324     } else {
02325       MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHWEST, 8, TRACK_X);
02326       MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHEAST, 9, TRACK_X);
02327     }
02328   } else {
02329     MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHEAST, 10, TRACK_Y);
02330     MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHWEST, 11, TRACK_Y);
02331   }
02332 }
02333 
02334 static void DrawTile_Track(TileInfo *ti)
02335 {
02336   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
02337 
02338   _drawtile_track_palette = COMPANY_SPRITE_COLOUR(GetTileOwner(ti->tile));
02339 
02340   if (IsPlainRail(ti->tile)) {
02341     TrackBits rails = GetTrackBits(ti->tile);
02342 
02343     DrawTrackBits(ti, rails);
02344 
02345     if (HasBit(_display_opt, DO_FULL_DETAIL)) DrawTrackDetails(ti, rti);
02346 
02347     if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
02348 
02349     if (HasSignals(ti->tile)) DrawSignals(ti->tile, rails);
02350   } else {
02351     /* draw depot */
02352     const DrawTileSprites *dts;
02353     PaletteID pal = PAL_NONE;
02354     SpriteID relocation;
02355 
02356     if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);
02357 
02358     if (IsInvisibilitySet(TO_BUILDINGS)) {
02359       /* Draw rail instead of depot */
02360       dts = &_depot_invisible_gfx_table[GetRailDepotDirection(ti->tile)];
02361     } else {
02362       dts = &_depot_gfx_table[GetRailDepotDirection(ti->tile)];
02363     }
02364 
02365     SpriteID image;
02366     if (rti->UsesOverlay()) {
02367       image = SPR_FLAT_GRASS_TILE;
02368     } else {
02369       image = dts->ground.sprite;
02370       if (image != SPR_FLAT_GRASS_TILE) image += rti->GetRailtypeSpriteOffset();
02371     }
02372 
02373     /* adjust ground tile for desert
02374      * don't adjust for snow, because snow in depots looks weird */
02375     if (IsSnowRailGround(ti->tile) && _settings_game.game_creation.landscape == LT_TROPIC) {
02376       if (image != SPR_FLAT_GRASS_TILE) {
02377         image += rti->snow_offset; // tile with tracks
02378       } else {
02379         image = SPR_FLAT_SNOW_DESERT_TILE; // flat ground
02380       }
02381     }
02382 
02383     DrawGroundSprite(image, GroundSpritePaletteTransform(image, pal, _drawtile_track_palette));
02384 
02385     if (rti->UsesOverlay()) {
02386       SpriteID ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND);
02387 
02388       switch (GetRailDepotDirection(ti->tile)) {
02389         case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02390         case DIAGDIR_SW: DrawGroundSprite(ground + RTO_X, PAL_NONE); break;
02391         case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02392         case DIAGDIR_SE: DrawGroundSprite(ground + RTO_Y, PAL_NONE); break;
02393         default: break;
02394       }
02395 
02396       if (_settings_client.gui.show_track_reservation && HasDepotReservation(ti->tile)) {
02397         SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
02398 
02399         switch (GetRailDepotDirection(ti->tile)) {
02400           case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02401           case DIAGDIR_SW: DrawGroundSprite(overlay + RTO_X, PALETTE_CRASH); break;
02402           case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02403           case DIAGDIR_SE: DrawGroundSprite(overlay + RTO_Y, PALETTE_CRASH); break;
02404           default: break;
02405         }
02406       }
02407 
02408       int depot_sprite = GetCustomRailSprite(rti, ti->tile, RTSG_DEPOT);
02409       relocation = depot_sprite != 0 ? depot_sprite - SPR_RAIL_DEPOT_SE_1 : rti->GetRailtypeSpriteOffset();
02410     } else {
02411       /* PBS debugging, draw reserved tracks darker */
02412       if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasDepotReservation(ti->tile)) {
02413         switch (GetRailDepotDirection(ti->tile)) {
02414           case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02415           case DIAGDIR_SW: DrawGroundSprite(rti->base_sprites.single_x, PALETTE_CRASH); break;
02416           case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02417           case DIAGDIR_SE: DrawGroundSprite(rti->base_sprites.single_y, PALETTE_CRASH); break;
02418           default: break;
02419         }
02420       }
02421 
02422       relocation = rti->GetRailtypeSpriteOffset();
02423     }
02424 
02425     if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
02426 
02427     DrawRailTileSeq(ti, dts, TO_BUILDINGS, relocation, 0, _drawtile_track_palette);
02428   }
02429   DrawBridgeMiddle(ti);
02430 }
02431 
02432 void DrawTrainDepotSprite(int x, int y, int dir, RailType railtype)
02433 {
02434   const DrawTileSprites *dts = &_depot_gfx_table[dir];
02435   const RailtypeInfo *rti = GetRailTypeInfo(railtype);
02436   SpriteID image = rti->UsesOverlay() ? SPR_FLAT_GRASS_TILE : dts->ground.sprite;
02437   uint32 offset = rti->GetRailtypeSpriteOffset();
02438 
02439   x += 33;
02440   y += 17;
02441 
02442   if (image != SPR_FLAT_GRASS_TILE) image += offset;
02443   PaletteID palette = COMPANY_SPRITE_COLOUR(_local_company);
02444 
02445   DrawSprite(image, PAL_NONE, x, y);
02446 
02447   if (rti->UsesOverlay()) {
02448     SpriteID ground = GetCustomRailSprite(rti, INVALID_TILE, RTSG_GROUND);
02449 
02450     switch (dir) {
02451       case DIAGDIR_SW: DrawSprite(ground + RTO_X, PAL_NONE, x, y); break;
02452       case DIAGDIR_SE: DrawSprite(ground + RTO_Y, PAL_NONE, x, y); break;
02453       default: break;
02454     }
02455 
02456     int depot_sprite = GetCustomRailSprite(rti, INVALID_TILE, RTSG_DEPOT);
02457     if (depot_sprite != 0) offset = depot_sprite - SPR_RAIL_DEPOT_SE_1;
02458   }
02459 
02460   DrawRailTileSeqInGUI(x, y, dts, offset, 0, palette);
02461 }
02462 
02463 static uint GetSlopeZ_Track(TileIndex tile, uint x, uint y)
02464 {
02465   uint z;
02466   Slope tileh = GetTileSlope(tile, &z);
02467 
02468   if (tileh == SLOPE_FLAT) return z;
02469   if (IsPlainRail(tile)) {
02470     z += ApplyFoundationToSlope(GetRailFoundation(tileh, GetTrackBits(tile)), &tileh);
02471     return z + GetPartialZ(x & 0xF, y & 0xF, tileh);
02472   } else {
02473     return z + TILE_HEIGHT;
02474   }
02475 }
02476 
02477 static Foundation GetFoundation_Track(TileIndex tile, Slope tileh)
02478 {
02479   return IsPlainRail(tile) ? GetRailFoundation(tileh, GetTrackBits(tile)) : FlatteningFoundation(tileh);
02480 }
02481 
02482 static void TileLoop_Track(TileIndex tile)
02483 {
02484   RailGroundType old_ground = GetRailGroundType(tile);
02485   RailGroundType new_ground;
02486 
02487   ReduceStuckCounter(tile);
02488 
02489   if (old_ground == RAIL_GROUND_WATER) {
02490     TileLoop_Water(tile);
02491     return;
02492   }
02493 
02494   switch (_settings_game.game_creation.landscape) {
02495     case LT_ARCTIC: {
02496       uint z;
02497       Slope slope = GetTileSlope(tile, &z);
02498       bool half = false;
02499 
02500       /* for non-flat track, use lower part of track
02501        * in other cases, use the highest part with track */
02502       if (IsPlainRail(tile)) {
02503         TrackBits track = GetTrackBits(tile);
02504         Foundation f = GetRailFoundation(slope, track);
02505 
02506         switch (f) {
02507           case FOUNDATION_NONE:
02508             /* no foundation - is the track on the upper side of three corners raised tile? */
02509             if (IsSlopeWithThreeCornersRaised(slope)) z += TILE_HEIGHT;
02510             break;
02511 
02512           case FOUNDATION_INCLINED_X:
02513           case FOUNDATION_INCLINED_Y:
02514             /* sloped track - is it on a steep slope? */
02515             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
02516             break;
02517 
02518           case FOUNDATION_STEEP_LOWER:
02519             /* only lower part of steep slope */
02520             z += TILE_HEIGHT;
02521             break;
02522 
02523           default:
02524             /* if it is a steep slope, then there is a track on higher part */
02525             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
02526             z += TILE_HEIGHT;
02527             break;
02528         }
02529 
02530         half = IsInsideMM(f, FOUNDATION_STEEP_BOTH, FOUNDATION_HALFTILE_N + 1);
02531       } else {
02532         /* is the depot on a non-flat tile? */
02533         if (slope != SLOPE_FLAT) z += TILE_HEIGHT;
02534       }
02535 
02536       /* 'z' is now the lowest part of the highest track bit -
02537        * for sloped track, it is 'z' of lower part
02538        * for two track bits, it is 'z' of higher track bit
02539        * For non-continuous foundations (and STEEP_BOTH), 'half' is set */
02540       if (z > GetSnowLine()) {
02541         if (half && z - GetSnowLine() == TILE_HEIGHT) {
02542           /* track on non-continuous foundation, lower part is not under snow */
02543           new_ground = RAIL_GROUND_HALF_SNOW;
02544         } else {
02545           new_ground = RAIL_GROUND_ICE_DESERT;
02546         }
02547         goto set_ground;
02548       }
02549       break;
02550       }
02551 
02552     case LT_TROPIC:
02553       if (GetTropicZone(tile) == TROPICZONE_DESERT) {
02554         new_ground = RAIL_GROUND_ICE_DESERT;
02555         goto set_ground;
02556       }
02557       break;
02558   }
02559 
02560   new_ground = RAIL_GROUND_GRASS;
02561 
02562   if (IsPlainRail(tile) && old_ground != RAIL_GROUND_BARREN) { // wait until bottom is green
02563     /* determine direction of fence */
02564     TrackBits rail = GetTrackBits(tile);
02565 
02566     switch (rail) {
02567       case TRACK_BIT_UPPER: new_ground = RAIL_GROUND_FENCE_HORIZ1; break;
02568       case TRACK_BIT_LOWER: new_ground = RAIL_GROUND_FENCE_HORIZ2; break;
02569       case TRACK_BIT_LEFT:  new_ground = RAIL_GROUND_FENCE_VERT1;  break;
02570       case TRACK_BIT_RIGHT: new_ground = RAIL_GROUND_FENCE_VERT2;  break;
02571 
02572       default: {
02573         Owner owner = GetTileOwner(tile);
02574 
02575         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_RIGHT) || (
02576               (rail & TRACK_BIT_3WAY_NW) == 0 &&
02577               (rail & TRACK_BIT_X)
02578             )) {
02579           TileIndex n = tile + TileDiffXY(0, -1);
02580           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02581 
02582           if (!IsTileType(n, MP_RAILWAY) ||
02583               !IsTileOwner(n, owner) ||
02584               nrail == TRACK_BIT_UPPER ||
02585               nrail == TRACK_BIT_LEFT) {
02586             new_ground = RAIL_GROUND_FENCE_NW;
02587           }
02588         }
02589 
02590         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_LEFT) || (
02591               (rail & TRACK_BIT_3WAY_SE) == 0 &&
02592               (rail & TRACK_BIT_X)
02593             )) {
02594           TileIndex n = tile + TileDiffXY(0, 1);
02595           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02596 
02597           if (!IsTileType(n, MP_RAILWAY) ||
02598               !IsTileOwner(n, owner) ||
02599               nrail == TRACK_BIT_LOWER ||
02600               nrail == TRACK_BIT_RIGHT) {
02601             new_ground = (new_ground == RAIL_GROUND_FENCE_NW) ?
02602               RAIL_GROUND_FENCE_SENW : RAIL_GROUND_FENCE_SE;
02603           }
02604         }
02605 
02606         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_LEFT) || (
02607               (rail & TRACK_BIT_3WAY_NE) == 0 &&
02608               (rail & TRACK_BIT_Y)
02609             )) {
02610           TileIndex n = tile + TileDiffXY(-1, 0);
02611           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02612 
02613           if (!IsTileType(n, MP_RAILWAY) ||
02614               !IsTileOwner(n, owner) ||
02615               nrail == TRACK_BIT_UPPER ||
02616               nrail == TRACK_BIT_RIGHT) {
02617             new_ground = RAIL_GROUND_FENCE_NE;
02618           }
02619         }
02620 
02621         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_RIGHT) || (
02622               (rail & TRACK_BIT_3WAY_SW) == 0 &&
02623               (rail & TRACK_BIT_Y)
02624             )) {
02625           TileIndex n = tile + TileDiffXY(1, 0);
02626           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02627 
02628           if (!IsTileType(n, MP_RAILWAY) ||
02629               !IsTileOwner(n, owner) ||
02630               nrail == TRACK_BIT_LOWER ||
02631               nrail == TRACK_BIT_LEFT) {
02632             new_ground = (new_ground == RAIL_GROUND_FENCE_NE) ?
02633               RAIL_GROUND_FENCE_NESW : RAIL_GROUND_FENCE_SW;
02634           }
02635         }
02636         break;
02637       }
02638     }
02639   }
02640 
02641 set_ground:
02642   if (old_ground != new_ground) {
02643     SetRailGroundType(tile, new_ground);
02644     MarkTileDirtyByTile(tile);
02645   }
02646 }
02647 
02648 
02649 static TrackStatus GetTileTrackStatus_Track(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
02650 {
02651   /* Case of half tile slope with water. */
02652   if (mode == TRANSPORT_WATER && IsPlainRail(tile) && GetRailGroundType(tile) == RAIL_GROUND_WATER) {
02653     TrackBits tb = GetTrackBits(tile);
02654     switch (tb) {
02655       default: NOT_REACHED();
02656       case TRACK_BIT_UPPER: tb = TRACK_BIT_LOWER; break;
02657       case TRACK_BIT_LOWER: tb = TRACK_BIT_UPPER; break;
02658       case TRACK_BIT_LEFT:  tb = TRACK_BIT_RIGHT; break;
02659       case TRACK_BIT_RIGHT: tb = TRACK_BIT_LEFT;  break;
02660     }
02661     return CombineTrackStatus(TrackBitsToTrackdirBits(tb), TRACKDIR_BIT_NONE);
02662   }
02663 
02664   if (mode != TRANSPORT_RAIL) return 0;
02665 
02666   TrackBits trackbits = TRACK_BIT_NONE;
02667   TrackdirBits red_signals = TRACKDIR_BIT_NONE;
02668 
02669   switch (GetRailTileType(tile)) {
02670     default: NOT_REACHED();
02671     case RAIL_TILE_NORMAL:
02672       trackbits = GetTrackBits(tile);
02673       break;
02674 
02675     case RAIL_TILE_SIGNALS: {
02676       trackbits = GetTrackBits(tile);
02677       byte a = GetPresentSignals(tile);
02678       uint b = GetSignalStates(tile);
02679 
02680       b &= a;
02681 
02682       /* When signals are not present (in neither direction),
02683        * we pretend them to be green. Otherwise, it depends on
02684        * the signal type. For signals that are only active from
02685        * one side, we set the missing signals explicitely to
02686        * `green'. Otherwise, they implicitely become `red'. */
02687       if (!IsOnewaySignal(tile, TRACK_UPPER) || (a & SignalOnTrack(TRACK_UPPER)) == 0) b |= ~a & SignalOnTrack(TRACK_UPPER);
02688       if (!IsOnewaySignal(tile, TRACK_LOWER) || (a & SignalOnTrack(TRACK_LOWER)) == 0) b |= ~a & SignalOnTrack(TRACK_LOWER);
02689 
02690       if ((b & 0x8) == 0) red_signals |= (TRACKDIR_BIT_LEFT_N | TRACKDIR_BIT_X_NE | TRACKDIR_BIT_Y_SE | TRACKDIR_BIT_UPPER_E);
02691       if ((b & 0x4) == 0) red_signals |= (TRACKDIR_BIT_LEFT_S | TRACKDIR_BIT_X_SW | TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_UPPER_W);
02692       if ((b & 0x2) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_N | TRACKDIR_BIT_LOWER_E);
02693       if ((b & 0x1) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_S | TRACKDIR_BIT_LOWER_W);
02694 
02695       break;
02696     }
02697 
02698     case RAIL_TILE_DEPOT: {
02699       DiagDirection dir = GetRailDepotDirection(tile);
02700 
02701       if (side != INVALID_DIAGDIR && side != dir) break;
02702 
02703       trackbits = DiagDirToDiagTrackBits(dir);
02704       break;
02705     }
02706   }
02707 
02708   return CombineTrackStatus(TrackBitsToTrackdirBits(trackbits), red_signals);
02709 }
02710 
02711 static bool ClickTile_Track(TileIndex tile)
02712 {
02713   if (!IsRailDepot(tile)) return false;
02714 
02715   ShowDepotWindow(tile, VEH_TRAIN);
02716   return true;
02717 }
02718 
02719 static void GetTileDesc_Track(TileIndex tile, TileDesc *td)
02720 {
02721   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(tile));
02722   td->rail_speed = rti->max_speed;
02723   td->owner[0] = GetTileOwner(tile);
02724   switch (GetRailTileType(tile)) {
02725     case RAIL_TILE_NORMAL:
02726       td->str = STR_LAI_RAIL_DESCRIPTION_TRACK;
02727       break;
02728 
02729     case RAIL_TILE_SIGNALS: {
02730       static const StringID signal_type[8][8] = {
02731         {
02732           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SIGNALS,
02733           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
02734           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_EXITSIGNALS,
02735           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_COMBOSIGNALS,
02736           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PBSSIGNALS,
02737           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_NOENTRYSIGNALS,
02738           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PROGSIGNALS,
02739           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SPEEDSIGNALS
02740         },
02741         {
02742           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
02743           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRESIGNALS,
02744           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_EXITSIGNALS,
02745           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_COMBOSIGNALS,
02746           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PBSSIGNALS,
02747           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_NOENTRYSIGNALS,
02748           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PROGSIGNALS,
02749           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_SPEEDSIGNALS
02750         },
02751         {
02752           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_EXITSIGNALS,
02753           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_EXITSIGNALS,
02754           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXITSIGNALS,
02755           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_COMBOSIGNALS,
02756           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PBSSIGNALS,
02757           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_NOENTRYSIGNALS,
02758           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PROGSIGNALS,
02759           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_SPEEDSIGNALS
02760         },
02761         {
02762           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_COMBOSIGNALS,
02763           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_COMBOSIGNALS,
02764           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_COMBOSIGNALS,
02765           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBOSIGNALS,
02766           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PBSSIGNALS,
02767           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS,
02768           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PROGSIGNALS,
02769           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_SPEEDSIGNALS
02770         },
02771         {
02772           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PBSSIGNALS,
02773           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PBSSIGNALS,
02774           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PBSSIGNALS,
02775           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PBSSIGNALS,
02776           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBSSIGNALS,
02777           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS,
02778           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_PROGSIGNALS,
02779           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_SPEEDSIGNALS
02780         },
02781         {
02782           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_NOENTRYSIGNALS,
02783           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_NOENTRYSIGNALS,
02784           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_NOENTRYSIGNALS,
02785           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS,
02786           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS,
02787           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRYSIGNALS,
02788           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRY_PROGSIGNALS,
02789           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRY_SPEEDSIGNALS
02790         },
02791         {
02792           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PROGSIGNALS,
02793           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PROGSIGNALS,
02794           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PROGSIGNALS,
02795           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PROGSIGNALS,
02796           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_PROGSIGNALS,
02797           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRY_PROGSIGNALS,
02798           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PROGSIGNALS,
02799           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PROG_SPEEDSIGNALS
02800         },
02801         {
02802           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SPEEDSIGNALS,
02803           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_SPEEDSIGNALS,
02804           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_SPEEDSIGNALS,
02805           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_SPEEDSIGNALS,
02806           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_SPEEDSIGNALS,
02807           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRY_SPEEDSIGNALS,
02808           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PROG_SPEEDSIGNALS,
02809           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_SPEEDSIGNALS
02810         }
02811       };
02812 
02813       SignalType primary_signal;
02814       SignalType secondary_signal;
02815       if (HasSignalOnTrack(tile, TRACK_UPPER)) {
02816         primary_signal = GetSignalType(tile, TRACK_UPPER);
02817         secondary_signal = HasSignalOnTrack(tile, TRACK_LOWER) ? GetSignalType(tile, TRACK_LOWER) : primary_signal;
02818       } else {
02819         secondary_signal = primary_signal = GetSignalType(tile, TRACK_LOWER);
02820       }
02821 
02822       td->str = signal_type[secondary_signal][primary_signal];
02823       break;
02824     }
02825 
02826     case RAIL_TILE_DEPOT:
02827       td->str = STR_LAI_RAIL_DESCRIPTION_TRAIN_DEPOT;
02828       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) {
02829         if (td->rail_speed > 0) {
02830           td->rail_speed = min(td->rail_speed, 61);
02831         } else {
02832           td->rail_speed = 61;
02833         }
02834       }
02835       td->build_date = Depot::GetByTile(tile)->build_date;
02836       break;
02837 
02838     default:
02839       NOT_REACHED();
02840   }
02841 }
02842 
02843 static void ChangeTileOwner_Track(TileIndex tile, Owner old_owner, Owner new_owner)
02844 {
02845   if (!IsTileOwner(tile, old_owner)) return;
02846 
02847   if (new_owner != INVALID_OWNER) {
02848     SetTileOwner(tile, new_owner);
02849   } else {
02850     DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR);
02851   }
02852 }
02853 
02854 static const byte _fractcoords_behind[4] = { 0x8F, 0x8, 0x80, 0xF8 };
02855 static const byte _fractcoords_enter[4] = { 0x8A, 0x48, 0x84, 0xA8 };
02856 static const int8 _deltacoord_leaveoffset[8] = {
02857   -1,  0,  1,  0, /* x */
02858    0,  1,  0, -1  /* y */
02859 };
02860 
02861 
02868 int TicksToLeaveDepot(const Train *v)
02869 {
02870   DiagDirection dir = GetRailDepotDirection(v->tile);
02871   int length = v->gcache.cached_veh_length;
02872 
02873   switch (dir) {
02874     case DIAGDIR_NE: return  ((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) - (length + 1)));
02875     case DIAGDIR_SE: return -((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   + (length + 1)));
02876     case DIAGDIR_SW: return -((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) + (length + 1)));
02877     default:
02878     case DIAGDIR_NW: return  ((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   - (length + 1)));
02879   }
02880 
02881   return 0; // make compilers happy
02882 }
02883 
02888 static VehicleEnterTileStatus VehicleEnter_Track(Vehicle *u, TileIndex tile, int x, int y)
02889 {
02890   /* this routine applies only to trains in depot tiles */
02891   if (u->type != VEH_TRAIN || !IsRailDepotTile(tile)) return VETSB_CONTINUE;
02892 
02893   Train *v = Train::From(u);
02894 
02895   /* depot direction */
02896   DiagDirection dir = GetRailDepotDirection(tile);
02897 
02898   /* calculate the point where the following wagon should be activated
02899    * this depends on the length of the current vehicle */
02900   int length = v->gcache.cached_veh_length;
02901 
02902   byte fract_coord_leave =
02903     ((_fractcoords_enter[dir] & 0x0F) + // x
02904       (length + 1) * _deltacoord_leaveoffset[dir]) +
02905     (((_fractcoords_enter[dir] >> 4) +  // y
02906       ((length + 1) * _deltacoord_leaveoffset[dir + 4])) << 4);
02907 
02908   byte fract_coord = (x & 0xF) + ((y & 0xF) << 4);
02909 
02910   if (_fractcoords_behind[dir] == fract_coord) {
02911     /* make sure a train is not entering the tile from behind */
02912     return VETSB_CANNOT_ENTER;
02913   } else if (_fractcoords_enter[dir] == fract_coord) {
02914     if (DiagDirToDir(ReverseDiagDir(dir)) == v->direction) {
02915       /* enter the depot */
02916       v->track = TRACK_BIT_DEPOT,
02917       v->vehstatus |= VS_HIDDEN; // hide it
02918       v->direction = ReverseDir(v->direction);
02919       if (v->Next() == NULL) VehicleEnterDepot(v->First());
02920       v->tile = tile;
02921 
02922       InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02923       return VETSB_ENTERED_WORMHOLE;
02924     }
02925   } else if (fract_coord_leave == fract_coord) {
02926     if (DiagDirToDir(dir) == v->direction) {
02927       /* leave the depot? */
02928       if ((v = v->Next()) != NULL) {
02929         v->vehstatus &= ~VS_HIDDEN;
02930         v->track = (DiagDirToAxis(dir) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y);
02931       }
02932     }
02933   }
02934 
02935   return VETSB_CONTINUE;
02936 }
02937 
02949 static CommandCost TestAutoslopeOnRailTile(TileIndex tile, uint flags, uint z_old, Slope tileh_old, uint z_new, Slope tileh_new, TrackBits rail_bits)
02950 {
02951   if (!_settings_game.construction.build_on_slopes || !AutoslopeEnabled()) return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
02952 
02953   /* Is the slope-rail_bits combination valid in general? I.e. is it safe to call GetRailFoundation() ? */
02954   if (CheckRailSlope(tileh_new, rail_bits, TRACK_BIT_NONE, tile).Failed()) return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
02955 
02956   /* Get the slopes on top of the foundations */
02957   z_old += ApplyFoundationToSlope(GetRailFoundation(tileh_old, rail_bits), &tileh_old);
02958   z_new += ApplyFoundationToSlope(GetRailFoundation(tileh_new, rail_bits), &tileh_new);
02959 
02960   Corner track_corner;
02961   switch (rail_bits) {
02962     case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
02963     case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
02964     case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
02965     case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
02966 
02967     /* Surface slope must not be changed */
02968     default:
02969       if (z_old != z_new || tileh_old != tileh_new) return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
02970       return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
02971   }
02972 
02973   /* The height of the track_corner must not be changed. The rest ensures GetRailFoundation() already. */
02974   z_old += GetSlopeZInCorner(RemoveHalftileSlope(tileh_old), track_corner);
02975   z_new += GetSlopeZInCorner(RemoveHalftileSlope(tileh_new), track_corner);
02976   if (z_old != z_new) return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
02977 
02978   CommandCost cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
02979   /* Make the ground dirty, if surface slope has changed */
02980   if (tileh_old != tileh_new) {
02981     /* If there is flat water on the lower halftile add the cost for clearing it */
02982     if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old)) cost.AddCost(_price[PR_CLEAR_WATER]);
02983     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
02984   }
02985   return  cost;
02986 }
02987 
02988 static CommandCost TerraformTile_Track(TileIndex tile, DoCommandFlag flags, uint z_new, Slope tileh_new)
02989 {
02990   uint z_old;
02991   Slope tileh_old = GetTileSlope(tile, &z_old);
02992   if (IsPlainRail(tile)) {
02993     TrackBits rail_bits = GetTrackBits(tile);
02994     /* Is there flat water on the lower halftile that must be cleared expensively? */
02995     bool was_water = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old));
02996 
02997     /* First test autoslope. However if it succeeds we still have to test the rest, because non-autoslope terraforming is cheaper. */
02998     CommandCost autoslope_result = TestAutoslopeOnRailTile(tile, flags, z_old, tileh_old, z_new, tileh_new, rail_bits);
02999 
03000     /* When there is only a single horizontal/vertical track, one corner can be terraformed. */
03001     Corner allowed_corner;
03002     switch (rail_bits) {
03003       case TRACK_BIT_RIGHT: allowed_corner = CORNER_W; break;
03004       case TRACK_BIT_UPPER: allowed_corner = CORNER_S; break;
03005       case TRACK_BIT_LEFT:  allowed_corner = CORNER_E; break;
03006       case TRACK_BIT_LOWER: allowed_corner = CORNER_N; break;
03007       default: return autoslope_result;
03008     }
03009 
03010     Foundation f_old = GetRailFoundation(tileh_old, rail_bits);
03011 
03012     /* Do not allow terraforming if allowed_corner is part of anti-zig-zag foundations */
03013     if (tileh_old != SLOPE_NS && tileh_old != SLOPE_EW && IsSpecialRailFoundation(f_old)) return autoslope_result;
03014 
03015     /* Everything is valid, which only changes allowed_corner */
03016     for (Corner corner = (Corner)0; corner < CORNER_END; corner = (Corner)(corner + 1)) {
03017       if (allowed_corner == corner) continue;
03018       if (z_old + GetSlopeZInCorner(tileh_old, corner) != z_new + GetSlopeZInCorner(tileh_new, corner)) return autoslope_result;
03019     }
03020 
03021     /* Make the ground dirty */
03022     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
03023 
03024     /* allow terraforming */
03025     return CommandCost(EXPENSES_CONSTRUCTION, was_water ? _price[PR_CLEAR_WATER] : (Money)0);
03026   } else if (_settings_game.construction.build_on_slopes && AutoslopeEnabled() &&
03027       AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRailDepotDirection(tile))) {
03028     return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
03029   }
03030   return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
03031 }
03032 
03033 
03034 extern const TileTypeProcs _tile_type_rail_procs = {
03035   DrawTile_Track,           // draw_tile_proc
03036   GetSlopeZ_Track,          // get_slope_z_proc
03037   ClearTile_Track,          // clear_tile_proc
03038   NULL,                     // add_accepted_cargo_proc
03039   GetTileDesc_Track,        // get_tile_desc_proc
03040   GetTileTrackStatus_Track, // get_tile_track_status_proc
03041   ClickTile_Track,          // click_tile_proc
03042   NULL,                     // animate_tile_proc
03043   TileLoop_Track,           // tile_loop_clear
03044   ChangeTileOwner_Track,    // change_tile_owner_clear
03045   NULL,                     // add_produced_cargo_proc
03046   VehicleEnter_Track,       // vehicle_enter_tile_proc
03047   GetFoundation_Track,      // get_foundation_proc
03048   TerraformTile_Track,      // terraform_tile_proc
03049 };