rail_cmd.cpp

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00001 /* $Id: rail_cmd.cpp 19439 2010-03-16 20:54:26Z rubidium $ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "cmd_helper.h"
00014 #include "landscape.h"
00015 #include "viewport_func.h"
00016 #include "command_func.h"
00017 #include "engine_base.h"
00018 #include "depot_base.h"
00019 #include "pathfinder/yapf/yapf_cache.h"
00020 #include "newgrf_engine.h"
00021 #include "landscape_type.h"
00022 #include "newgrf_railtype.h"
00023 #include "newgrf_commons.h"
00024 #include "train.h"
00025 #include "variables.h"
00026 #include "autoslope.h"
00027 #include "water.h"
00028 #include "tunnelbridge_map.h"
00029 #include "window_func.h"
00030 #include "vehicle_func.h"
00031 #include "sound_func.h"
00032 #include "tunnelbridge.h"
00033 #include "functions.h"
00034 #include "elrail_func.h"
00035 #include "town.h"
00036 #include "pbs.h"
00037 #include "company_base.h"
00038 
00039 #include "table/strings.h"
00040 #include "table/sprites.h"
00041 #include "table/railtypes.h"
00042 #include "table/track_land.h"
00043 
00044 RailtypeInfo _railtypes[RAILTYPE_END];
00045 
00046 assert_compile(sizeof(_original_railtypes) <= sizeof(_railtypes));
00047 
00051 void ResetRailTypes()
00052 {
00053   memset(_railtypes, 0, sizeof(_railtypes));
00054   memcpy(_railtypes, _original_railtypes, sizeof(_original_railtypes));
00055 }
00056 
00057 void ResolveRailTypeGUISprites(RailtypeInfo *rti)
00058 {
00059   SpriteID cursors_base = GetCustomRailSprite(rti, INVALID_TILE, RTSG_CURSORS);
00060   if (cursors_base != 0) {
00061     rti->gui_sprites.build_ns_rail = cursors_base +  0;
00062     rti->gui_sprites.build_x_rail  = cursors_base +  1;
00063     rti->gui_sprites.build_ew_rail = cursors_base +  2;
00064     rti->gui_sprites.build_y_rail  = cursors_base +  3;
00065     rti->gui_sprites.auto_rail     = cursors_base +  4;
00066     rti->gui_sprites.build_depot   = cursors_base +  5;
00067     rti->gui_sprites.build_tunnel  = cursors_base +  6;
00068     rti->gui_sprites.convert_rail  = cursors_base +  7;
00069     rti->cursor.rail_ns   = cursors_base +  8;
00070     rti->cursor.rail_swne = cursors_base +  9;
00071     rti->cursor.rail_ew   = cursors_base + 10;
00072     rti->cursor.rail_nwse = cursors_base + 11;
00073     rti->cursor.autorail  = cursors_base + 12;
00074     rti->cursor.depot     = cursors_base + 13;
00075     rti->cursor.tunnel    = cursors_base + 14;
00076     rti->cursor.convert   = cursors_base + 15;
00077   }
00078 }
00079 
00080 void InitRailTypes()
00081 {
00082   for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
00083     RailtypeInfo *rti = &_railtypes[rt];
00084     ResolveRailTypeGUISprites(rti);
00085   }
00086 }
00087 
00088 RailType AllocateRailType(RailTypeLabel label)
00089 {
00090   for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
00091     RailtypeInfo *rti = &_railtypes[rt];
00092 
00093     if (rti->label == 0) {
00094       /* Set up new rail type */
00095       memcpy(rti, &_railtypes[RAILTYPE_RAIL], sizeof(*rti));
00096       rti->label = label;
00097 
00098       /* Make us compatible with ourself. */
00099       rti->powered_railtypes    = (RailTypes)(1 << rt);
00100       rti->compatible_railtypes = (RailTypes)(1 << rt);
00101       return rt;
00102     }
00103   }
00104 
00105   return INVALID_RAILTYPE;
00106 }
00107 
00108 static const byte _track_sloped_sprites[14] = {
00109   14, 15, 22, 13,
00110    0, 21, 17, 12,
00111   23,  0, 18, 20,
00112   19, 16
00113 };
00114 
00115 
00116 /*         4
00117  *     ---------
00118  *    |\       /|
00119  *    | \    1/ |
00120  *    |  \   /  |
00121  *    |   \ /   |
00122  *  16|    \    |32
00123  *    |   / \2  |
00124  *    |  /   \  |
00125  *    | /     \ |
00126  *    |/       \|
00127  *     ---------
00128  *         8
00129  */
00130 
00131 
00132 
00133 /* MAP2 byte:    abcd???? => Signal On? Same coding as map3lo
00134  * MAP3LO byte:  abcd???? => Signal Exists?
00135  *               a and b are for diagonals, upper and left,
00136  *               one for each direction. (ie a == NE->SW, b ==
00137  *               SW->NE, or v.v., I don't know. b and c are
00138  *               similar for lower and right.
00139  * MAP2 byte:    ????abcd => Type of ground.
00140  * MAP3LO byte:  ????abcd => Type of rail.
00141  * MAP5:         00abcdef => rail
00142  *               01abcdef => rail w/ signals
00143  *               10uuuuuu => unused
00144  *               11uuuudd => rail depot
00145  */
00146 
00147 
00148 Vehicle *EnsureNoTrainOnTrackProc(Vehicle *v, void *data)
00149 {
00150   TrackBits rail_bits = *(TrackBits *)data;
00151 
00152   if (v->type != VEH_TRAIN) return NULL;
00153 
00154   Train *t = Train::From(v);
00155   if ((t->track != rail_bits) && !TracksOverlap(t->track | rail_bits)) return NULL;
00156 
00157   _error_message = STR_ERROR_TRAIN_IN_THE_WAY + v->type;
00158   return v;
00159 }
00160 
00168 static bool EnsureNoTrainOnTrack(TileIndex tile, Track track)
00169 {
00170   TrackBits rail_bits = TrackToTrackBits(track);
00171 
00172   return !HasVehicleOnPos(tile, &rail_bits, &EnsureNoTrainOnTrackProc);
00173 }
00174 
00181 static CommandCost CheckTrackCombination(TileIndex tile, TrackBits to_build, uint flags)
00182 {
00183   if (!IsPlainRail(tile)) return_cmd_error(STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION);
00184 
00185   /* So, we have a tile with tracks on it (and possibly signals). Let's see
00186    * what tracks first */
00187   TrackBits current = GetTrackBits(tile); // The current track layout.
00188   TrackBits future = current | to_build;  // The track layout we want to build.
00189 
00190   /* Are we really building something new? */
00191   if (current == future) {
00192     /* Nothing new is being built */
00193     return_cmd_error(STR_ERROR_ALREADY_BUILT);
00194   }
00195 
00196   /* Let's see if we may build this */
00197   if ((flags & DC_NO_RAIL_OVERLAP) || HasSignals(tile)) {
00198     /* If we are not allowed to overlap (flag is on for ai companies or we have
00199      * signals on the tile), check that */
00200     if (future != TRACK_BIT_HORZ && future != TRACK_BIT_VERT) {
00201       return_cmd_error((flags & DC_NO_RAIL_OVERLAP) ? STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION : STR_ERROR_MUST_REMOVE_SIGNALS_FIRST);
00202     }
00203   }
00204   /* Normally, we may overlap and any combination is valid */
00205   return CommandCost();
00206 }
00207 
00208 
00210 static const TrackBits _valid_tracks_without_foundation[15] = {
00211   TRACK_BIT_ALL,
00212   TRACK_BIT_RIGHT,
00213   TRACK_BIT_UPPER,
00214   TRACK_BIT_X,
00215 
00216   TRACK_BIT_LEFT,
00217   TRACK_BIT_NONE,
00218   TRACK_BIT_Y,
00219   TRACK_BIT_LOWER,
00220 
00221   TRACK_BIT_LOWER,
00222   TRACK_BIT_Y,
00223   TRACK_BIT_NONE,
00224   TRACK_BIT_LEFT,
00225 
00226   TRACK_BIT_X,
00227   TRACK_BIT_UPPER,
00228   TRACK_BIT_RIGHT,
00229 };
00230 
00232 static const TrackBits _valid_tracks_on_leveled_foundation[15] = {
00233   TRACK_BIT_NONE,
00234   TRACK_BIT_LEFT,
00235   TRACK_BIT_LOWER,
00236   TRACK_BIT_Y | TRACK_BIT_LOWER | TRACK_BIT_LEFT,
00237 
00238   TRACK_BIT_RIGHT,
00239   TRACK_BIT_ALL,
00240   TRACK_BIT_X | TRACK_BIT_LOWER | TRACK_BIT_RIGHT,
00241   TRACK_BIT_ALL,
00242 
00243   TRACK_BIT_UPPER,
00244   TRACK_BIT_X | TRACK_BIT_UPPER | TRACK_BIT_LEFT,
00245   TRACK_BIT_ALL,
00246   TRACK_BIT_ALL,
00247 
00248   TRACK_BIT_Y | TRACK_BIT_UPPER | TRACK_BIT_RIGHT,
00249   TRACK_BIT_ALL,
00250   TRACK_BIT_ALL
00251 };
00252 
00260 Foundation GetRailFoundation(Slope tileh, TrackBits bits)
00261 {
00262   if (bits == TRACK_BIT_NONE) return FOUNDATION_NONE;
00263 
00264   if (IsSteepSlope(tileh)) {
00265     /* Test for inclined foundations */
00266     if (bits == TRACK_BIT_X) return FOUNDATION_INCLINED_X;
00267     if (bits == TRACK_BIT_Y) return FOUNDATION_INCLINED_Y;
00268 
00269     /* Get higher track */
00270     Corner highest_corner = GetHighestSlopeCorner(tileh);
00271     TrackBits higher_track = CornerToTrackBits(highest_corner);
00272 
00273     /* Only higher track? */
00274     if (bits == higher_track) return HalftileFoundation(highest_corner);
00275 
00276     /* Overlap with higher track? */
00277     if (TracksOverlap(bits | higher_track)) return FOUNDATION_INVALID;
00278 
00279     /* either lower track or both higher and lower track */
00280     return ((bits & higher_track) != 0 ? FOUNDATION_STEEP_BOTH : FOUNDATION_STEEP_LOWER);
00281   } else {
00282     if ((~_valid_tracks_without_foundation[tileh] & bits) == 0) return FOUNDATION_NONE;
00283 
00284     bool valid_on_leveled = ((~_valid_tracks_on_leveled_foundation[tileh] & bits) == 0);
00285 
00286     Corner track_corner;
00287     switch (bits) {
00288       case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
00289       case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
00290       case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
00291       case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
00292 
00293       case TRACK_BIT_HORZ:
00294         if (tileh == SLOPE_N) return HalftileFoundation(CORNER_N);
00295         if (tileh == SLOPE_S) return HalftileFoundation(CORNER_S);
00296         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00297 
00298       case TRACK_BIT_VERT:
00299         if (tileh == SLOPE_W) return HalftileFoundation(CORNER_W);
00300         if (tileh == SLOPE_E) return HalftileFoundation(CORNER_E);
00301         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00302 
00303       case TRACK_BIT_X:
00304         if (IsSlopeWithOneCornerRaised(tileh)) return FOUNDATION_INCLINED_X;
00305         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00306 
00307       case TRACK_BIT_Y:
00308         if (IsSlopeWithOneCornerRaised(tileh)) return FOUNDATION_INCLINED_Y;
00309         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00310 
00311       default:
00312         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00313     }
00314     /* Single diagonal track */
00315 
00316     /* Track must be at least valid on leveled foundation */
00317     if (!valid_on_leveled) return FOUNDATION_INVALID;
00318 
00319     /* If slope has three raised corners, build leveled foundation */
00320     if (IsSlopeWithThreeCornersRaised(tileh)) return FOUNDATION_LEVELED;
00321 
00322     /* If neighboured corners of track_corner are lowered, build halftile foundation */
00323     if ((tileh & SlopeWithThreeCornersRaised(OppositeCorner(track_corner))) == SlopeWithOneCornerRaised(track_corner)) return HalftileFoundation(track_corner);
00324 
00325     /* else special anti-zig-zag foundation */
00326     return SpecialRailFoundation(track_corner);
00327   }
00328 }
00329 
00330 
00340 static CommandCost CheckRailSlope(Slope tileh, TrackBits rail_bits, TrackBits existing, TileIndex tile)
00341 {
00342   /* don't allow building on the lower side of a coast */
00343   if (IsTileType(tile, MP_WATER) || (IsTileType(tile, MP_RAILWAY) && (GetRailGroundType(tile) == RAIL_GROUND_WATER))) {
00344     if (!IsSteepSlope(tileh) && ((~_valid_tracks_on_leveled_foundation[tileh] & (rail_bits | existing)) != 0)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
00345   }
00346 
00347   Foundation f_new = GetRailFoundation(tileh, rail_bits | existing);
00348 
00349   /* check track/slope combination */
00350   if ((f_new == FOUNDATION_INVALID) ||
00351       ((f_new != FOUNDATION_NONE) && (!_settings_game.construction.build_on_slopes))) {
00352     return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00353   }
00354 
00355   Foundation f_old = GetRailFoundation(tileh, existing);
00356   return CommandCost(EXPENSES_CONSTRUCTION, f_new != f_old ? _price[PR_BUILD_FOUNDATION] : (Money)0);
00357 }
00358 
00359 /* Validate functions for rail building */
00360 static inline bool ValParamTrackOrientation(Track track) {return IsValidTrack(track);}
00361 
00370 CommandCost CmdBuildSingleRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00371 {
00372   RailType railtype = (RailType)p1;
00373   Track track = (Track)p2;
00374   CommandCost cost(EXPENSES_CONSTRUCTION);
00375 
00376   if (!ValParamRailtype(railtype) || !ValParamTrackOrientation(track)) return CMD_ERROR;
00377 
00378   Slope tileh = GetTileSlope(tile, NULL);
00379   TrackBits trackbit = TrackToTrackBits(track);
00380 
00381   switch (GetTileType(tile)) {
00382     case MP_RAILWAY: {
00383       if (!CheckTileOwnership(tile)) return CMD_ERROR;
00384 
00385       if (!IsPlainRail(tile)) return CMD_ERROR;
00386 
00387       if (!IsCompatibleRail(GetRailType(tile), railtype)) return_cmd_error(STR_ERROR_IMPOSSIBLE_TRACK_COMBINATION);
00388 
00389       CommandCost ret = CheckTrackCombination(tile, trackbit, flags);
00390       ret.SetGlobalErrorMessage();
00391       if (ret.Failed()) return ret;
00392 
00393       if (!EnsureNoTrainOnTrack(tile, track)) return CMD_ERROR;
00394 
00395       ret = CheckRailSlope(tileh, trackbit, GetTrackBits(tile), tile);
00396       if (ret.Failed()) return ret;
00397       cost.AddCost(ret);
00398 
00399       /* If the rail types don't match, try to convert only if engines of
00400        * the new rail type are not powered on the present rail type and engines of
00401        * the present rail type are powered on the new rail type. */
00402       if (GetRailType(tile) != railtype && !HasPowerOnRail(railtype, GetRailType(tile))) {
00403         if (HasPowerOnRail(GetRailType(tile), railtype)) {
00404           ret = DoCommand(tile, tile, railtype, flags, CMD_CONVERT_RAIL);
00405           if (ret.Failed()) return ret;
00406           cost.AddCost(ret);
00407         } else {
00408           return CMD_ERROR;
00409         }
00410       }
00411 
00412       if (flags & DC_EXEC) {
00413         SetRailGroundType(tile, RAIL_GROUND_BARREN);
00414         SetTrackBits(tile, GetTrackBits(tile) | trackbit);
00415       }
00416       break;
00417     }
00418 
00419     case MP_ROAD:
00420 #define M(x) (1 << (x))
00421       /* Level crossings may only be built on these slopes */
00422       if (!HasBit(M(SLOPE_SEN) | M(SLOPE_ENW) | M(SLOPE_NWS) | M(SLOPE_NS) | M(SLOPE_WSE) | M(SLOPE_EW) | M(SLOPE_FLAT), tileh)) {
00423         return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
00424       }
00425 #undef M
00426 
00427       if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
00428 
00429       if (IsNormalRoad(tile)) {
00430         if (HasRoadWorks(tile)) return_cmd_error(STR_ERROR_ROAD_WORKS_IN_PROGRESS);
00431 
00432         if (GetDisallowedRoadDirections(tile) != DRD_NONE) return_cmd_error(STR_ERROR_CROSSING_ON_ONEWAY_ROAD);
00433 
00434         RoadTypes roadtypes = GetRoadTypes(tile);
00435         RoadBits road = GetRoadBits(tile, ROADTYPE_ROAD);
00436         RoadBits tram = GetRoadBits(tile, ROADTYPE_TRAM);
00437         switch (roadtypes) {
00438           default: break;
00439           case ROADTYPES_TRAM:
00440             /* Tram crossings must always have road. */
00441             if (flags & DC_EXEC) SetRoadOwner(tile, ROADTYPE_ROAD, _current_company);
00442             roadtypes |= ROADTYPES_ROAD;
00443             break;
00444 
00445           case ROADTYPES_ALL:
00446             if (road != tram) return CMD_ERROR;
00447             break;
00448         }
00449 
00450         road |= tram;
00451 
00452         if ((track == TRACK_X && road == ROAD_Y) ||
00453             (track == TRACK_Y && road == ROAD_X)) {
00454           if (flags & DC_EXEC) {
00455             MakeRoadCrossing(tile, GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM), _current_company, (track == TRACK_X ? AXIS_Y : AXIS_X), railtype, roadtypes, GetTownIndex(tile));
00456             UpdateLevelCrossing(tile, false);
00457           }
00458           break;
00459         }
00460       }
00461 
00462       if (IsLevelCrossing(tile) && GetCrossingRailBits(tile) == trackbit) {
00463         return_cmd_error(STR_ERROR_ALREADY_BUILT);
00464       }
00465       /* FALLTHROUGH */
00466 
00467     default: {
00468       /* Will there be flat water on the lower halftile? */
00469       bool water_ground = IsTileType(tile, MP_WATER) && IsSlopeWithOneCornerRaised(tileh);
00470 
00471       CommandCost ret = CheckRailSlope(tileh, trackbit, TRACK_BIT_NONE, tile);
00472       if (ret.Failed()) return ret;
00473       cost.AddCost(ret);
00474 
00475       ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00476       if (ret.Failed()) return ret;
00477       cost.AddCost(ret);
00478 
00479       if (water_ground) {
00480         cost.AddCost(-_price[PR_CLEAR_WATER]);
00481         cost.AddCost(_price[PR_CLEAR_ROUGH]);
00482       }
00483 
00484       if (flags & DC_EXEC) {
00485         MakeRailNormal(tile, _current_company, trackbit, railtype);
00486         if (water_ground) SetRailGroundType(tile, RAIL_GROUND_WATER);
00487       }
00488       break;
00489     }
00490   }
00491 
00492   if (flags & DC_EXEC) {
00493     MarkTileDirtyByTile(tile);
00494     AddTrackToSignalBuffer(tile, track, _current_company);
00495     YapfNotifyTrackLayoutChange(tile, track);
00496   }
00497 
00498   cost.AddCost(RailBuildCost(railtype));
00499   return cost;
00500 }
00501 
00510 CommandCost CmdRemoveSingleRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00511 {
00512   Track track = (Track)p2;
00513   CommandCost cost(EXPENSES_CONSTRUCTION);
00514   bool crossing = false;
00515 
00516   if (!ValParamTrackOrientation((Track)p2)) return CMD_ERROR;
00517   TrackBits trackbit = TrackToTrackBits(track);
00518 
00519   /* Need to read tile owner now because it may change when the rail is removed
00520    * Also, in case of floods, _current_company != owner
00521    * There may be invalid tiletype even in exec run (when removing long track),
00522    * so do not call GetTileOwner(tile) in any case here */
00523   Owner owner = INVALID_OWNER;
00524 
00525   Train *v = NULL;
00526 
00527   switch (GetTileType(tile)) {
00528     case MP_ROAD: {
00529       if (!IsLevelCrossing(tile) ||
00530           GetCrossingRailBits(tile) != trackbit ||
00531           (_current_company != OWNER_WATER && !CheckTileOwnership(tile)) ||
00532           (!(flags & DC_BANKRUPT) && !EnsureNoVehicleOnGround(tile))) {
00533         return CMD_ERROR;
00534       }
00535 
00536       cost.AddCost(RailClearCost(GetRailType(tile)));
00537 
00538       if (flags & DC_EXEC) {
00539         if (HasReservedTracks(tile, trackbit)) {
00540           v = GetTrainForReservation(tile, track);
00541           if (v != NULL) FreeTrainTrackReservation(v);
00542         }
00543         owner = GetTileOwner(tile);
00544         MakeRoadNormal(tile, GetCrossingRoadBits(tile), GetRoadTypes(tile), GetTownIndex(tile), GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM));
00545       }
00546       break;
00547     }
00548 
00549     case MP_RAILWAY: {
00550       TrackBits present;
00551 
00552       if (!IsPlainRail(tile) ||
00553           (_current_company != OWNER_WATER && !CheckTileOwnership(tile)) ||
00554           !EnsureNoTrainOnTrack(tile, track)) {
00555         return CMD_ERROR;
00556       }
00557 
00558       present = GetTrackBits(tile);
00559       if ((present & trackbit) == 0) return CMD_ERROR;
00560       if (present == (TRACK_BIT_X | TRACK_BIT_Y)) crossing = true;
00561 
00562       cost.AddCost(RailClearCost(GetRailType(tile)));
00563 
00564       /* Charge extra to remove signals on the track, if they are there */
00565       if (HasSignalOnTrack(tile, track))
00566         cost.AddCost(DoCommand(tile, track, 0, flags, CMD_REMOVE_SIGNALS));
00567 
00568       if (flags & DC_EXEC) {
00569         if (HasReservedTracks(tile, trackbit)) {
00570           v = GetTrainForReservation(tile, track);
00571           if (v != NULL) FreeTrainTrackReservation(v);
00572         }
00573         owner = GetTileOwner(tile);
00574         present ^= trackbit;
00575         if (present == 0) {
00576           Slope tileh = GetTileSlope(tile, NULL);
00577           /* If there is flat water on the lower halftile, convert the tile to shore so the water remains */
00578           if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh)) {
00579             MakeShore(tile);
00580           } else {
00581             DoClearSquare(tile);
00582           }
00583         } else {
00584           SetTrackBits(tile, present);
00585           SetTrackReservation(tile, GetRailReservationTrackBits(tile) & present);
00586         }
00587       }
00588       break;
00589     }
00590 
00591     default: return CMD_ERROR;
00592   }
00593 
00594   if (flags & DC_EXEC) {
00595     /* if we got that far, 'owner' variable is set correctly */
00596     assert(Company::IsValidID(owner));
00597 
00598     MarkTileDirtyByTile(tile);
00599     if (crossing) {
00600       /* crossing is set when only TRACK_BIT_X and TRACK_BIT_Y are set. As we
00601        * are removing one of these pieces, we'll need to update signals for
00602        * both directions explicitly, as after the track is removed it won't
00603        * 'connect' with the other piece. */
00604       AddTrackToSignalBuffer(tile, TRACK_X, owner);
00605       AddTrackToSignalBuffer(tile, TRACK_Y, owner);
00606       YapfNotifyTrackLayoutChange(tile, TRACK_X);
00607       YapfNotifyTrackLayoutChange(tile, TRACK_Y);
00608     } else {
00609       AddTrackToSignalBuffer(tile, track, owner);
00610       YapfNotifyTrackLayoutChange(tile, track);
00611     }
00612 
00613     if (v != NULL) TryPathReserve(v, true);
00614   }
00615 
00616   return cost;
00617 }
00618 
00619 
00627 bool FloodHalftile(TileIndex t)
00628 {
00629   assert(IsPlainRailTile(t));
00630 
00631   bool flooded = false;
00632   if (GetRailGroundType(t) == RAIL_GROUND_WATER) return flooded;
00633 
00634   Slope tileh = GetTileSlope(t, NULL);
00635   TrackBits rail_bits = GetTrackBits(t);
00636 
00637   if (IsSlopeWithOneCornerRaised(tileh)) {
00638     TrackBits lower_track = CornerToTrackBits(OppositeCorner(GetHighestSlopeCorner(tileh)));
00639 
00640     TrackBits to_remove = lower_track & rail_bits;
00641     if (to_remove != 0) {
00642       _current_company = OWNER_WATER;
00643       if (DoCommand(t, 0, FIND_FIRST_BIT(to_remove), DC_EXEC, CMD_REMOVE_SINGLE_RAIL).Failed()) return flooded; // not yet floodable
00644       flooded = true;
00645       rail_bits = rail_bits & ~to_remove;
00646       if (rail_bits == 0) {
00647         MakeShore(t);
00648         MarkTileDirtyByTile(t);
00649         return flooded;
00650       }
00651     }
00652 
00653     if (IsNonContinuousFoundation(GetRailFoundation(tileh, rail_bits))) {
00654       flooded = true;
00655       SetRailGroundType(t, RAIL_GROUND_WATER);
00656       MarkTileDirtyByTile(t);
00657     }
00658   } else {
00659     /* Make shore on steep slopes and 'three-corners-raised'-slopes. */
00660     if (ApplyFoundationToSlope(GetRailFoundation(tileh, rail_bits), &tileh) == 0) {
00661       if (IsSteepSlope(tileh) || IsSlopeWithThreeCornersRaised(tileh)) {
00662         flooded = true;
00663         SetRailGroundType(t, RAIL_GROUND_WATER);
00664         MarkTileDirtyByTile(t);
00665       }
00666     }
00667   }
00668   return flooded;
00669 }
00670 
00671 static const TileIndexDiffC _trackdelta[] = {
00672   { -1,  0 }, {  0,  1 }, { -1,  0 }, {  0,  1 }, {  1,  0 }, {  0,  1 },
00673   {  0,  0 },
00674   {  0,  0 },
00675   {  1,  0 }, {  0, -1 }, {  0, -1 }, {  1,  0 }, {  0, -1 }, { -1,  0 },
00676   {  0,  0 },
00677   {  0,  0 }
00678 };
00679 
00680 
00681 static CommandCost ValidateAutoDrag(Trackdir *trackdir, TileIndex start, TileIndex end)
00682 {
00683   int x = TileX(start);
00684   int y = TileY(start);
00685   int ex = TileX(end);
00686   int ey = TileY(end);
00687 
00688   if (!ValParamTrackOrientation(TrackdirToTrack(*trackdir))) return CMD_ERROR;
00689 
00690   /* calculate delta x,y from start to end tile */
00691   int dx = ex - x;
00692   int dy = ey - y;
00693 
00694   /* calculate delta x,y for the first direction */
00695   int trdx = _trackdelta[*trackdir].x;
00696   int trdy = _trackdelta[*trackdir].y;
00697 
00698   if (!IsDiagonalTrackdir(*trackdir)) {
00699     trdx += _trackdelta[*trackdir ^ 1].x;
00700     trdy += _trackdelta[*trackdir ^ 1].y;
00701   }
00702 
00703   /* validate the direction */
00704   while (
00705     (trdx <= 0 && dx > 0) ||
00706     (trdx >= 0 && dx < 0) ||
00707     (trdy <= 0 && dy > 0) ||
00708     (trdy >= 0 && dy < 0)
00709   ) {
00710     if (!HasBit(*trackdir, 3)) { // first direction is invalid, try the other
00711       SetBit(*trackdir, 3); // reverse the direction
00712       trdx = -trdx;
00713       trdy = -trdy;
00714     } else { // other direction is invalid too, invalid drag
00715       return CMD_ERROR;
00716     }
00717   }
00718 
00719   /* (for diagonal tracks, this is already made sure of by above test), but:
00720    * for non-diagonal tracks, check if the start and end tile are on 1 line */
00721   if (!IsDiagonalTrackdir(*trackdir)) {
00722     trdx = _trackdelta[*trackdir].x;
00723     trdy = _trackdelta[*trackdir].y;
00724     if (abs(dx) != abs(dy) && abs(dx) + abs(trdy) != abs(dy) + abs(trdx))
00725       return CMD_ERROR;
00726   }
00727 
00728   return CommandCost();
00729 }
00730 
00743 static CommandCost CmdRailTrackHelper(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00744 {
00745   CommandCost ret, total_cost(EXPENSES_CONSTRUCTION);
00746   Track track = (Track)GB(p2, 4, 3);
00747   bool remove = HasBit(p2, 7);
00748   RailType railtype = (RailType)GB(p2, 0, 4);
00749 
00750   if (!ValParamRailtype(railtype) || !ValParamTrackOrientation(track)) return CMD_ERROR;
00751   if (p1 >= MapSize()) return CMD_ERROR;
00752   TileIndex end_tile = p1;
00753   Trackdir trackdir = TrackToTrackdir(track);
00754 
00755   if (ValidateAutoDrag(&trackdir, tile, end_tile).Failed()) return CMD_ERROR;
00756 
00757   if (flags & DC_EXEC) SndPlayTileFx(SND_20_SPLAT_2, tile);
00758 
00759   for (;;) {
00760     ret = DoCommand(tile, railtype, TrackdirToTrack(trackdir), flags, remove ? CMD_REMOVE_SINGLE_RAIL : CMD_BUILD_SINGLE_RAIL);
00761 
00762     if (ret.Failed()) {
00763       if (_error_message != STR_ERROR_ALREADY_BUILT && !remove) {
00764         if (HasBit(p2, 8)) return CMD_ERROR;
00765         break;
00766       }
00767       _error_message = INVALID_STRING_ID;
00768     } else {
00769       total_cost.AddCost(ret);
00770     }
00771 
00772     if (tile == end_tile) break;
00773 
00774     tile += ToTileIndexDiff(_trackdelta[trackdir]);
00775 
00776     /* toggle railbit for the non-diagonal tracks */
00777     if (!IsDiagonalTrackdir(trackdir)) ToggleBit(trackdir, 0);
00778   }
00779 
00780   return (total_cost.GetCost() == 0) ? CommandCost(remove ? INVALID_STRING_ID : (_error_message == INVALID_STRING_ID ? STR_ERROR_ALREADY_BUILT : _error_message)) : total_cost;
00781 }
00782 
00796 CommandCost CmdBuildRailroadTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00797 {
00798   return CmdRailTrackHelper(tile, flags, p1, ClrBit(p2, 7), text);
00799 }
00800 
00814 CommandCost CmdRemoveRailroadTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00815 {
00816   return CmdRailTrackHelper(tile, flags, p1, SetBit(p2, 7), text);
00817 }
00818 
00830 CommandCost CmdBuildTrainDepot(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00831 {
00832   /* check railtype and valid direction for depot (0 through 3), 4 in total */
00833   if (!ValParamRailtype((RailType)p1)) return CMD_ERROR;
00834 
00835   Slope tileh = GetTileSlope(tile, NULL);
00836 
00837   DiagDirection dir = Extract<DiagDirection, 0>(p2);
00838 
00839   /* Prohibit construction if
00840    * The tile is non-flat AND
00841    * 1) build-on-slopes is disabled
00842    * 2) the tile is steep i.e. spans two height levels
00843    * 3) the exit points in the wrong direction
00844    */
00845 
00846   if (tileh != SLOPE_FLAT && (
00847         !_settings_game.construction.build_on_slopes ||
00848         IsSteepSlope(tileh) ||
00849         !CanBuildDepotByTileh(dir, tileh)
00850       )) {
00851     return_cmd_error(STR_ERROR_FLAT_LAND_REQUIRED);
00852   }
00853 
00854   CommandCost cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00855   if (cost.Failed()) return CMD_ERROR;
00856 
00857   if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00858 
00859   if (!Depot::CanAllocateItem()) return CMD_ERROR;
00860 
00861   if (flags & DC_EXEC) {
00862     Depot *d = new Depot(tile);
00863     d->town_index = ClosestTownFromTile(tile, UINT_MAX)->index;
00864 
00865     MakeRailDepot(tile, _current_company, d->index, dir, (RailType)p1);
00866     MarkTileDirtyByTile(tile);
00867 
00868     AddSideToSignalBuffer(tile, INVALID_DIAGDIR, _current_company);
00869     YapfNotifyTrackLayoutChange(tile, DiagDirToDiagTrack(dir));
00870   }
00871 
00872   cost.AddCost(_price[PR_BUILD_DEPOT_TRAIN]);
00873   return cost;
00874 }
00875 
00896 CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00897 {
00898   Track track = (Track)GB(p1, 0, 3);
00899   bool ctrl_pressed = HasBit(p1, 3); // was the CTRL button pressed
00900   SignalVariant sigvar = (ctrl_pressed ^ HasBit(p1, 4)) ? SIG_SEMAPHORE : SIG_ELECTRIC; // the signal variant of the new signal
00901   SignalType sigtype = (SignalType)GB(p1, 5, 3); // the signal type of the new signal
00902   bool convert_signal = HasBit(p1, 8); // convert button pressed
00903   SignalType cycle_start = (SignalType)GB(p1, 9, 3);
00904   SignalType cycle_stop = (SignalType)GB(p1, 12, 3);
00905   uint num_dir_cycle = GB(p1, 15, 2);
00906 
00907   if (sigtype > SIGTYPE_LAST) return CMD_ERROR;
00908 
00909   /* You can only build signals on plain rail tiles, and the selected track must exist */
00910   if (!ValParamTrackOrientation(track) || !IsPlainRailTile(tile) ||
00911       !HasTrack(tile, track) || !EnsureNoTrainOnTrack(tile, track)) {
00912     return CMD_ERROR;
00913   }
00914 
00915   /* Protect against invalid signal copying */
00916   if (p2 != 0 && (p2 & SignalOnTrack(track)) == 0) return CMD_ERROR;
00917 
00918   if (!CheckTileOwnership(tile)) return CMD_ERROR;
00919 
00920   {
00921     /* See if this is a valid track combination for signals, (ie, no overlap) */
00922     TrackBits trackbits = GetTrackBits(tile);
00923     if (KillFirstBit(trackbits) != TRACK_BIT_NONE && // More than one track present
00924         trackbits != TRACK_BIT_HORZ &&
00925         trackbits != TRACK_BIT_VERT) {
00926       return_cmd_error(STR_ERROR_NO_SUITABLE_RAILROAD_TRACK);
00927     }
00928   }
00929 
00930   /* In case we don't want to change an existing signal, return without error. */
00931   if (HasBit(p1, 17) && HasSignalOnTrack(tile, track)) return CommandCost();
00932 
00933   /* you can not convert a signal if no signal is on track */
00934   if (convert_signal && !HasSignalOnTrack(tile, track)) return CMD_ERROR;
00935 
00936   CommandCost cost;
00937   if (!HasSignalOnTrack(tile, track)) {
00938     /* build new signals */
00939     cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS]);
00940   } else {
00941     if (p2 != 0 && sigvar != GetSignalVariant(tile, track)) {
00942       /* convert signals <-> semaphores */
00943       cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]);
00944 
00945     } else if (convert_signal) {
00946       /* convert button pressed */
00947       if (ctrl_pressed || GetSignalVariant(tile, track) != sigvar) {
00948         /* convert electric <-> semaphore */
00949         cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]);
00950       } else {
00951         /* it is free to change signal type: normal-pre-exit-combo */
00952         cost = CommandCost();
00953       }
00954 
00955     } else {
00956       /* it is free to change orientation/pre-exit-combo signals */
00957       cost = CommandCost();
00958     }
00959   }
00960 
00961   if (flags & DC_EXEC) {
00962     Train *v = NULL;
00963     /* The new/changed signal could block our path. As this can lead to
00964      * stale reservations, we clear the path reservation here and try
00965      * to redo it later on. */
00966     if (HasReservedTracks(tile, TrackToTrackBits(track))) {
00967       v = GetTrainForReservation(tile, track);
00968       if (v != NULL) FreeTrainTrackReservation(v);
00969     }
00970 
00971     if (!HasSignals(tile)) {
00972       /* there are no signals at all on this tile yet */
00973       SetHasSignals(tile, true);
00974       SetSignalStates(tile, 0xF); // all signals are on
00975       SetPresentSignals(tile, 0); // no signals built by default
00976       SetSignalType(tile, track, sigtype);
00977       SetSignalVariant(tile, track, sigvar);
00978     }
00979 
00980     if (p2 == 0) {
00981       if (!HasSignalOnTrack(tile, track)) {
00982         /* build new signals */
00983         SetPresentSignals(tile, GetPresentSignals(tile) | (IsPbsSignal(sigtype) ? KillFirstBit(SignalOnTrack(track)) : SignalOnTrack(track)));
00984         SetSignalType(tile, track, sigtype);
00985         SetSignalVariant(tile, track, sigvar);
00986         while (num_dir_cycle-- > 0) CycleSignalSide(tile, track);
00987       } else {
00988         if (convert_signal) {
00989           /* convert signal button pressed */
00990           if (ctrl_pressed) {
00991             /* toggle the pressent signal variant: SIG_ELECTRIC <-> SIG_SEMAPHORE */
00992             SetSignalVariant(tile, track, (GetSignalVariant(tile, track) == SIG_ELECTRIC) ? SIG_SEMAPHORE : SIG_ELECTRIC);
00993             /* Query current signal type so the check for PBS signals below works. */
00994             sigtype = GetSignalType(tile, track);
00995           } else {
00996             /* convert the present signal to the chosen type and variant */
00997             SetSignalType(tile, track, sigtype);
00998             SetSignalVariant(tile, track, sigvar);
00999             if (IsPbsSignal(sigtype) && (GetPresentSignals(tile) & SignalOnTrack(track)) == SignalOnTrack(track)) {
01000               SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | KillFirstBit(SignalOnTrack(track)));
01001             }
01002           }
01003 
01004         } else if (ctrl_pressed) {
01005           /* cycle between cycle_start and cycle_end */
01006           sigtype = (SignalType)(GetSignalType(tile, track) + 1);
01007 
01008           if (sigtype < cycle_start || sigtype > cycle_stop) sigtype = cycle_start;
01009 
01010           SetSignalType(tile, track, sigtype);
01011           if (IsPbsSignal(sigtype) && (GetPresentSignals(tile) & SignalOnTrack(track)) == SignalOnTrack(track)) {
01012             SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | KillFirstBit(SignalOnTrack(track)));
01013           }
01014         } else {
01015           /* cycle the signal side: both -> left -> right -> both -> ... */
01016           CycleSignalSide(tile, track);
01017           /* Query current signal type so the check for PBS signals below works. */
01018           sigtype = GetSignalType(tile, track);
01019         }
01020       }
01021     } else {
01022       /* If CmdBuildManySignals is called with copying signals, just copy the
01023        * direction of the first signal given as parameter by CmdBuildManySignals */
01024       SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | (p2 & SignalOnTrack(track)));
01025       SetSignalVariant(tile, track, sigvar);
01026       SetSignalType(tile, track, sigtype);
01027     }
01028 
01029     if (IsPbsSignal(sigtype)) {
01030       /* PBS signals should show red unless they are on a reservation. */
01031       uint mask = GetPresentSignals(tile) & SignalOnTrack(track);
01032       SetSignalStates(tile, (GetSignalStates(tile) & ~mask) | ((HasBit(GetRailReservationTrackBits(tile), track) ? UINT_MAX : 0) & mask));
01033     }
01034     MarkTileDirtyByTile(tile);
01035     AddTrackToSignalBuffer(tile, track, _current_company);
01036     YapfNotifyTrackLayoutChange(tile, track);
01037     if (v != NULL) {
01038       /* Extend the train's path if it's not stopped or loading, or not at a safe position. */
01039       if (!(((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) || v->current_order.IsType(OT_LOADING)) ||
01040           !IsSafeWaitingPosition(v, v->tile, v->GetVehicleTrackdir(), true, _settings_game.pf.forbid_90_deg)) {
01041         TryPathReserve(v, true);
01042       }
01043     }
01044   }
01045 
01046   return cost;
01047 }
01048 
01049 static bool CheckSignalAutoFill(TileIndex &tile, Trackdir &trackdir, int &signal_ctr, bool remove)
01050 {
01051   tile = AddTileIndexDiffCWrap(tile, _trackdelta[trackdir]);
01052   if (tile == INVALID_TILE) return false;
01053 
01054   /* Check for track bits on the new tile */
01055   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0));
01056 
01057   if (TracksOverlap(TrackdirBitsToTrackBits(trackdirbits))) return false;
01058   trackdirbits &= TrackdirReachesTrackdirs(trackdir);
01059 
01060   /* No track bits, must stop */
01061   if (trackdirbits == TRACKDIR_BIT_NONE) return false;
01062 
01063   /* Get the first track dir */
01064   trackdir = RemoveFirstTrackdir(&trackdirbits);
01065 
01066   /* Any left? It's a junction so we stop */
01067   if (trackdirbits != TRACKDIR_BIT_NONE) return false;
01068 
01069   switch (GetTileType(tile)) {
01070     case MP_RAILWAY:
01071       if (IsRailDepot(tile)) return false;
01072       if (!remove && HasSignalOnTrack(tile, TrackdirToTrack(trackdir))) return false;
01073       signal_ctr++;
01074       if (IsDiagonalTrackdir(trackdir)) {
01075         signal_ctr++;
01076         /* Ensure signal_ctr even so X and Y pieces get signals */
01077         ClrBit(signal_ctr, 0);
01078       }
01079       return true;
01080 
01081     case MP_ROAD:
01082       if (!IsLevelCrossing(tile)) return false;
01083       signal_ctr += 2;
01084       return true;
01085 
01086     case MP_TUNNELBRIDGE: {
01087       TileIndex orig_tile = tile; // backup old value
01088 
01089       if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return false;
01090       if (GetTunnelBridgeDirection(tile) != TrackdirToExitdir(trackdir)) return false;
01091 
01092       /* Skip to end of tunnel or bridge
01093        * note that tile is a parameter by reference, so it must be updated */
01094       tile = GetOtherTunnelBridgeEnd(tile);
01095 
01096       signal_ctr += (GetTunnelBridgeLength(orig_tile, tile) + 2) * 2;
01097       return true;
01098     }
01099 
01100     default: return false;
01101   }
01102 }
01103 
01119 static CommandCost CmdSignalTrackHelper(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01120 {
01121   CommandCost ret, total_cost(EXPENSES_CONSTRUCTION);
01122   bool err = true;
01123   TileIndex start_tile = tile;
01124 
01125   Track track = (Track)GB(p2, 0, 3);
01126   bool mode = HasBit(p2, 3);
01127   bool semaphores = HasBit(p2, 4);
01128   bool remove = HasBit(p2, 5);
01129   bool autofill = HasBit(p2, 6);
01130   Trackdir trackdir = TrackToTrackdir(track);
01131   byte signal_density = GB(p2, 24, 8);
01132 
01133   if (p1 >= MapSize()) return CMD_ERROR;
01134   TileIndex end_tile = p1;
01135   if (signal_density == 0 || signal_density > 20) return CMD_ERROR;
01136 
01137   if (!IsPlainRailTile(tile)) return CMD_ERROR;
01138 
01139   /* for vertical/horizontal tracks, double the given signals density
01140    * since the original amount will be too dense (shorter tracks) */
01141   signal_density *= 2;
01142 
01143   if (ValidateAutoDrag(&trackdir, tile, end_tile).Failed()) return CMD_ERROR;
01144 
01145   track = TrackdirToTrack(trackdir); // trackdir might have changed, keep track in sync
01146   Trackdir start_trackdir = trackdir;
01147 
01148   /* Must start on a valid track to be able to avoid loops */
01149   if (!HasTrack(tile, track)) return CMD_ERROR;
01150 
01151   SignalType sigtype = (SignalType)GB(p2, 7, 3);
01152   if (sigtype > SIGTYPE_LAST) return CMD_ERROR;
01153 
01154   byte signals;
01155   /* copy the signal-style of the first rail-piece if existing */
01156   if (HasSignalOnTrack(tile, track)) {
01157     signals = GetPresentSignals(tile) & SignalOnTrack(track);
01158     assert(signals != 0);
01159 
01160     /* copy signal/semaphores style (independent of CTRL) */
01161     semaphores = GetSignalVariant(tile, track) != SIG_ELECTRIC;
01162 
01163     sigtype = GetSignalType(tile, track);
01164     /* Don't but copy pre-signal type */
01165     if (sigtype < SIGTYPE_PBS) sigtype = SIGTYPE_NORMAL;
01166   } else { // no signals exist, drag a two-way signal stretch
01167     signals = IsPbsSignal(sigtype) ? SignalAlongTrackdir(trackdir) : SignalOnTrack(track);
01168   }
01169 
01170   byte signal_dir = 0;
01171   if (signals & SignalAlongTrackdir(trackdir))   SetBit(signal_dir, 0);
01172   if (signals & SignalAgainstTrackdir(trackdir)) SetBit(signal_dir, 1);
01173 
01174   /* signal_ctr         - amount of tiles already processed
01175    * signals_density    - setting to put signal on every Nth tile (double space on |, -- tracks)
01176    **********
01177    * trackdir   - trackdir to build with autorail
01178    * semaphores - semaphores or signals
01179    * signals    - is there a signal/semaphore on the first tile, copy its style (two-way/single-way)
01180    *              and convert all others to semaphore/signal
01181    * remove     - 1 remove signals, 0 build signals */
01182   int signal_ctr = 0;
01183   for (;;) {
01184     /* only build/remove signals with the specified density */
01185     if ((remove && autofill) || signal_ctr % signal_density == 0) {
01186       uint32 p1 = GB(TrackdirToTrack(trackdir), 0, 3);
01187       SB(p1, 3, 1, mode);
01188       SB(p1, 4, 1, semaphores);
01189       SB(p1, 5, 3, sigtype);
01190       if (!remove && signal_ctr == 0) SetBit(p1, 17);
01191 
01192       /* Pick the correct orientation for the track direction */
01193       signals = 0;
01194       if (HasBit(signal_dir, 0)) signals |= SignalAlongTrackdir(trackdir);
01195       if (HasBit(signal_dir, 1)) signals |= SignalAgainstTrackdir(trackdir);
01196 
01197       ret = DoCommand(tile, p1, signals, flags, remove ? CMD_REMOVE_SIGNALS : CMD_BUILD_SIGNALS);
01198 
01199       /* Be user-friendly and try placing signals as much as possible */
01200       if (ret.Succeeded()) {
01201         err = false;
01202         total_cost.AddCost(ret);
01203       }
01204     }
01205 
01206     if (autofill) {
01207       if (!CheckSignalAutoFill(tile, trackdir, signal_ctr, remove)) break;
01208 
01209       /* Prevent possible loops */
01210       if (tile == start_tile && trackdir == start_trackdir) break;
01211     } else {
01212       if (tile == end_tile) break;
01213 
01214       tile += ToTileIndexDiff(_trackdelta[trackdir]);
01215       signal_ctr++;
01216 
01217       /* toggle railbit for the non-diagonal tracks (|, -- tracks) */
01218       if (IsDiagonalTrackdir(trackdir)) {
01219         signal_ctr++;
01220       } else {
01221         ToggleBit(trackdir, 0);
01222       }
01223     }
01224   }
01225 
01226   return err ? CMD_ERROR : total_cost;
01227 }
01228 
01246 CommandCost CmdBuildSignalTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01247 {
01248   return CmdSignalTrackHelper(tile, flags, p1, p2, text);
01249 }
01250 
01262 CommandCost CmdRemoveSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01263 {
01264   Track track = (Track)GB(p1, 0, 3);
01265 
01266   if (!ValParamTrackOrientation(track) ||
01267       !IsPlainRailTile(tile) ||
01268       !HasTrack(tile, track) ||
01269       !EnsureNoTrainOnTrack(tile, track) ||
01270       !HasSignalOnTrack(tile, track)) {
01271     return CMD_ERROR;
01272   }
01273 
01274   /* Only water can remove signals from anyone */
01275   if (_current_company != OWNER_WATER && !CheckTileOwnership(tile)) return CMD_ERROR;
01276 
01277   /* Do it? */
01278   if (flags & DC_EXEC) {
01279     Train *v = NULL;
01280     if (HasReservedTracks(tile, TrackToTrackBits(track))) {
01281       v = GetTrainForReservation(tile, track);
01282     } else if (IsPbsSignal(GetSignalType(tile, track))) {
01283       /* PBS signal, might be the end of a path reservation. */
01284       Trackdir td = TrackToTrackdir(track);
01285       for (int i = 0; v == NULL && i < 2; i++, td = ReverseTrackdir(td)) {
01286         /* Only test the active signal side. */
01287         if (!HasSignalOnTrackdir(tile, ReverseTrackdir(td))) continue;
01288         TileIndex next = TileAddByDiagDir(tile, TrackdirToExitdir(td));
01289         TrackBits tracks = TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(td));
01290         if (HasReservedTracks(next, tracks)) {
01291           v = GetTrainForReservation(next, TrackBitsToTrack(GetReservedTrackbits(next) & tracks));
01292         }
01293       }
01294     }
01295     SetPresentSignals(tile, GetPresentSignals(tile) & ~SignalOnTrack(track));
01296 
01297     /* removed last signal from tile? */
01298     if (GetPresentSignals(tile) == 0) {
01299       SetSignalStates(tile, 0);
01300       SetHasSignals(tile, false);
01301       SetSignalVariant(tile, INVALID_TRACK, SIG_ELECTRIC); // remove any possible semaphores
01302     }
01303 
01304     AddTrackToSignalBuffer(tile, track, GetTileOwner(tile));
01305     YapfNotifyTrackLayoutChange(tile, track);
01306     if (v != NULL) TryPathReserve(v, false);
01307 
01308     MarkTileDirtyByTile(tile);
01309   }
01310 
01311   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_SIGNALS]);
01312 }
01313 
01331 CommandCost CmdRemoveSignalTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01332 {
01333   return CmdSignalTrackHelper(tile, flags, p1, SetBit(p2, 5), text); // bit 5 is remove bit
01334 }
01335 
01337 static Vehicle *UpdateTrainPowerProc(Vehicle *v, void *data)
01338 {
01339   if (v->type != VEH_TRAIN) return NULL;
01340 
01341   /* Similar checks as in Train::PowerChanged() */
01342 
01343   Train *t = Train::From(v);
01344   if (t->IsArticulatedPart()) return NULL;
01345 
01346   const RailVehicleInfo *rvi = RailVehInfo(t->engine_type);
01347   if (GetVehicleProperty(t, PROP_TRAIN_POWER, rvi->power) != 0) t->First()->PowerChanged();
01348 
01349   return NULL;
01350 }
01351 
01361 CommandCost CmdConvertRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01362 {
01363   CommandCost cost(EXPENSES_CONSTRUCTION);
01364   RailType totype = (RailType)p2;
01365 
01366   if (!ValParamRailtype(totype)) return CMD_ERROR;
01367   if (p1 >= MapSize()) return CMD_ERROR;
01368 
01369   uint ex = TileX(tile);
01370   uint ey = TileY(tile);
01371   uint sx = TileX(p1);
01372   uint sy = TileY(p1);
01373 
01374   /* make sure sx,sy are smaller than ex,ey */
01375   if (ex < sx) Swap(ex, sx);
01376   if (ey < sy) Swap(ey, sy);
01377 
01378   _error_message = STR_ERROR_NO_SUITABLE_RAILROAD_TRACK; // by default, there is no track to convert
01379 
01380   for (uint x = sx; x <= ex; ++x) {
01381     for (uint y = sy; y <= ey; ++y) {
01382       TileIndex tile = TileXY(x, y);
01383       TileType tt = GetTileType(tile);
01384 
01385       /* Check if there is any track on tile */
01386       switch (tt) {
01387         case MP_RAILWAY:
01388           break;
01389         case MP_STATION:
01390           if (!HasStationRail(tile)) continue;
01391           break;
01392         case MP_ROAD:
01393           if (!IsLevelCrossing(tile)) continue;
01394           break;
01395         case MP_TUNNELBRIDGE:
01396           if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) continue;
01397           break;
01398         default: continue;
01399       }
01400 
01401       /* Original railtype we are converting from */
01402       RailType type = GetRailType(tile);
01403 
01404       /* Converting to the same type or converting 'hidden' elrail -> rail */
01405       if (type == totype || (_settings_game.vehicle.disable_elrails && totype == RAILTYPE_RAIL && type == RAILTYPE_ELECTRIC)) continue;
01406 
01407       /* Trying to convert other's rail */
01408       if (!CheckTileOwnership(tile)) continue;
01409 
01410       SmallVector<Train *, 2> vehicles_affected;
01411 
01412       /* Vehicle on the tile when not converting Rail <-> ElRail
01413        * Tunnels and bridges have special check later */
01414       if (tt != MP_TUNNELBRIDGE) {
01415         if (!IsCompatibleRail(type, totype) && !EnsureNoVehicleOnGround(tile)) continue;
01416         if (flags & DC_EXEC) { // we can safely convert, too
01417           TrackBits reserved = GetReservedTrackbits(tile);
01418           Track     track;
01419           while ((track = RemoveFirstTrack(&reserved)) != INVALID_TRACK) {
01420             Train *v = GetTrainForReservation(tile, track);
01421             if (v != NULL && !HasPowerOnRail(v->railtype, totype)) {
01422               /* No power on new rail type, reroute. */
01423               FreeTrainTrackReservation(v);
01424               *vehicles_affected.Append() = v;
01425             }
01426           }
01427 
01428           SetRailType(tile, totype);
01429           MarkTileDirtyByTile(tile);
01430           /* update power of train engines on this tile */
01431           FindVehicleOnPos(tile, NULL, &UpdateTrainPowerProc);
01432         }
01433       }
01434 
01435       switch (tt) {
01436         case MP_RAILWAY:
01437           switch (GetRailTileType(tile)) {
01438             case RAIL_TILE_DEPOT:
01439               if (flags & DC_EXEC) {
01440                 /* notify YAPF about the track layout change */
01441                 YapfNotifyTrackLayoutChange(tile, GetRailDepotTrack(tile));
01442 
01443                 /* Update build vehicle window related to this depot */
01444                 InvalidateWindowData(WC_VEHICLE_DEPOT, tile);
01445                 InvalidateWindowData(WC_BUILD_VEHICLE, tile);
01446               }
01447               cost.AddCost(RailConvertCost(type, totype));
01448               break;
01449 
01450             default: // RAIL_TILE_NORMAL, RAIL_TILE_SIGNALS
01451               if (flags & DC_EXEC) {
01452                 /* notify YAPF about the track layout change */
01453                 TrackBits tracks = GetTrackBits(tile);
01454                 while (tracks != TRACK_BIT_NONE) {
01455                   YapfNotifyTrackLayoutChange(tile, RemoveFirstTrack(&tracks));
01456                 }
01457               }
01458               cost.AddCost(RailConvertCost(type, totype) * CountBits(GetTrackBits(tile)));
01459               break;
01460           }
01461           break;
01462 
01463         case MP_TUNNELBRIDGE: {
01464           TileIndex endtile = GetOtherTunnelBridgeEnd(tile);
01465 
01466           /* If both ends of tunnel/bridge are in the range, do not try to convert twice -
01467            * it would cause assert because of different test and exec runs */
01468           if (endtile < tile && TileX(endtile) >= sx && TileX(endtile) <= ex &&
01469               TileY(endtile) >= sy && TileY(endtile) <= ey) continue;
01470 
01471           /* When not coverting rail <-> el. rail, any vehicle cannot be in tunnel/bridge */
01472           if (!IsCompatibleRail(GetRailType(tile), totype) &&
01473               HasVehicleOnTunnelBridge(tile, endtile)) continue;
01474 
01475           if (flags & DC_EXEC) {
01476             Track track = DiagDirToDiagTrack(GetTunnelBridgeDirection(tile));
01477             if (HasTunnelBridgeReservation(tile)) {
01478               Train *v = GetTrainForReservation(tile, track);
01479               if (v != NULL && !HasPowerOnRail(v->railtype, totype)) {
01480                 /* No power on new rail type, reroute. */
01481                 FreeTrainTrackReservation(v);
01482                 *vehicles_affected.Append() = v;
01483               }
01484             }
01485             SetRailType(tile, totype);
01486             SetRailType(endtile, totype);
01487 
01488             FindVehicleOnPos(tile, NULL, &UpdateTrainPowerProc);
01489             FindVehicleOnPos(endtile, NULL, &UpdateTrainPowerProc);
01490 
01491             YapfNotifyTrackLayoutChange(tile, track);
01492             YapfNotifyTrackLayoutChange(endtile, track);
01493 
01494             MarkTileDirtyByTile(tile);
01495             MarkTileDirtyByTile(endtile);
01496 
01497             if (IsBridge(tile)) {
01498               TileIndexDiff delta = TileOffsByDiagDir(GetTunnelBridgeDirection(tile));
01499               TileIndex t = tile + delta;
01500               for (; t != endtile; t += delta) MarkTileDirtyByTile(t); // TODO encapsulate this into a function
01501             }
01502           }
01503 
01504           cost.AddCost((GetTunnelBridgeLength(tile, endtile) + 2) * RailConvertCost(type, totype));
01505         } break;
01506 
01507         default: // MP_STATION, MP_ROAD
01508           if (flags & DC_EXEC) {
01509             Track track = ((tt == MP_STATION) ? GetRailStationTrack(tile) : GetCrossingRailTrack(tile));
01510             YapfNotifyTrackLayoutChange(tile, track);
01511           }
01512 
01513           cost.AddCost(RailConvertCost(type, totype));
01514           break;
01515       }
01516 
01517       for (uint i = 0; i < vehicles_affected.Length(); ++i) {
01518         TryPathReserve(vehicles_affected[i], true);
01519       }
01520     }
01521   }
01522 
01523   return (cost.GetCost() == 0) ? CMD_ERROR : cost;
01524 }
01525 
01526 static CommandCost RemoveTrainDepot(TileIndex tile, DoCommandFlag flags)
01527 {
01528   if (!CheckTileOwnership(tile) && _current_company != OWNER_WATER)
01529     return CMD_ERROR;
01530 
01531   if (!EnsureNoVehicleOnGround(tile))
01532     return CMD_ERROR;
01533 
01534   if (flags & DC_EXEC) {
01535     /* read variables before the depot is removed */
01536     DiagDirection dir = GetRailDepotDirection(tile);
01537     Owner owner = GetTileOwner(tile);
01538     Train *v = NULL;
01539 
01540     if (HasDepotReservation(tile)) {
01541       v = GetTrainForReservation(tile, DiagDirToDiagTrack(dir));
01542       if (v != NULL) FreeTrainTrackReservation(v);
01543     }
01544 
01545     delete Depot::GetByTile(tile);
01546     DoClearSquare(tile);
01547     AddSideToSignalBuffer(tile, dir, owner);
01548     YapfNotifyTrackLayoutChange(tile, DiagDirToDiagTrack(dir));
01549     if (v != NULL) TryPathReserve(v, true);
01550   }
01551 
01552   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_DEPOT_TRAIN]);
01553 }
01554 
01555 static CommandCost ClearTile_Track(TileIndex tile, DoCommandFlag flags)
01556 {
01557   CommandCost cost(EXPENSES_CONSTRUCTION);
01558 
01559   if (flags & DC_AUTO) {
01560     if (!IsTileOwner(tile, _current_company)) {
01561       return_cmd_error(STR_ERROR_AREA_IS_OWNED_BY_ANOTHER);
01562     }
01563 
01564     if (IsPlainRail(tile)) {
01565       return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
01566     } else {
01567       return_cmd_error(STR_ERROR_BUILDING_MUST_BE_DEMOLISHED);
01568     }
01569   }
01570 
01571   switch (GetRailTileType(tile)) {
01572     case RAIL_TILE_SIGNALS:
01573     case RAIL_TILE_NORMAL: {
01574       Slope tileh = GetTileSlope(tile, NULL);
01575       /* Is there flat water on the lower halftile, that gets cleared expensively? */
01576       bool water_ground = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh));
01577 
01578       TrackBits tracks = GetTrackBits(tile);
01579       while (tracks != TRACK_BIT_NONE) {
01580         Track track = RemoveFirstTrack(&tracks);
01581         CommandCost ret = DoCommand(tile, 0, track, flags, CMD_REMOVE_SINGLE_RAIL);
01582         if (ret.Failed()) return CMD_ERROR;
01583         cost.AddCost(ret);
01584       }
01585 
01586       /* when bankrupting, don't make water dirty, there could be a ship on lower halftile */
01587       if (water_ground && !(flags & DC_BANKRUPT)) {
01588         if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
01589 
01590         /* The track was removed, and left a coast tile. Now also clear the water. */
01591         if (flags & DC_EXEC) DoClearSquare(tile);
01592         cost.AddCost(_price[PR_CLEAR_WATER]);
01593       }
01594 
01595       return cost;
01596     }
01597 
01598     case RAIL_TILE_DEPOT:
01599       return RemoveTrainDepot(tile, flags);
01600 
01601     default:
01602       return CMD_ERROR;
01603   }
01604 }
01605 
01610 static uint GetSaveSlopeZ(uint x, uint y, Track track)
01611 {
01612   switch (track) {
01613     case TRACK_UPPER: x &= ~0xF; y &= ~0xF; break;
01614     case TRACK_LOWER: x |=  0xF; y |=  0xF; break;
01615     case TRACK_LEFT:  x |=  0xF; y &= ~0xF; break;
01616     case TRACK_RIGHT: x &= ~0xF; y |=  0xF; break;
01617     default: break;
01618   }
01619   return GetSlopeZ(x, y);
01620 }
01621 
01622 static void DrawSingleSignal(TileIndex tile, Track track, byte condition, uint image, uint pos)
01623 {
01624   bool side = (_settings_game.vehicle.road_side != 0) && _settings_game.construction.signal_side;
01625   static const Point SignalPositions[2][12] = {
01626     { // Signals on the left side
01627     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01628       { 8,  5}, {14,  1}, { 1, 14}, { 9, 11}, { 1,  0}, { 3, 10},
01629     /*  LOWER     LOWER     X         X         Y         Y     */
01630       {11,  4}, {14, 14}, {11,  3}, { 4, 13}, { 3,  4}, {11, 13}
01631     }, { // Signals on the right side
01632     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01633       {14,  1}, {12, 10}, { 4,  6}, { 1, 14}, {10,  4}, { 0,  1},
01634     /*  LOWER     LOWER     X         X         Y         Y     */
01635       {14, 14}, { 5, 12}, {11, 13}, { 4,  3}, {13,  4}, { 3, 11}
01636     }
01637   };
01638 
01639   uint x = TileX(tile) * TILE_SIZE + SignalPositions[side][pos].x;
01640   uint y = TileY(tile) * TILE_SIZE + SignalPositions[side][pos].y;
01641 
01642   SpriteID sprite;
01643 
01644   SignalType type       = GetSignalType(tile, track);
01645   SignalVariant variant = GetSignalVariant(tile, track);
01646 
01647   if (type == SIGTYPE_NORMAL && variant == SIG_ELECTRIC) {
01648     /* Normal electric signals are picked from original sprites. */
01649     sprite = SPR_ORIGINAL_SIGNALS_BASE + image + condition;
01650   } else {
01651     /* All other signals are picked from add on sprites. */
01652     sprite = SPR_SIGNALS_BASE + (type - 1) * 16 + variant * 64 + image + condition + (type > SIGTYPE_LAST_NOPBS ? 64 : 0);
01653   }
01654 
01655   AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
01656 }
01657 
01658 static uint32 _drawtile_track_palette;
01659 
01660 
01661 static void DrawTrackFence_NW(const TileInfo *ti, SpriteID base_image)
01662 {
01663   RailFenceOffset rfo = RFO_FLAT_X;
01664   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SW : RFO_SLOPE_NE;
01665   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01666     ti->x, ti->y + 1, 16, 1, 4, ti->z);
01667 }
01668 
01669 static void DrawTrackFence_SE(const TileInfo *ti, SpriteID base_image)
01670 {
01671   RailFenceOffset rfo = RFO_FLAT_X;
01672   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SW : RFO_SLOPE_NE;
01673   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01674     ti->x, ti->y + TILE_SIZE - 1, 16, 1, 4, ti->z);
01675 }
01676 
01677 static void DrawTrackFence_NW_SE(const TileInfo *ti, SpriteID base_image)
01678 {
01679   DrawTrackFence_NW(ti, base_image);
01680   DrawTrackFence_SE(ti, base_image);
01681 }
01682 
01683 static void DrawTrackFence_NE(const TileInfo *ti, SpriteID base_image)
01684 {
01685   RailFenceOffset rfo = RFO_FLAT_Y;
01686   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SE : RFO_SLOPE_NW;
01687   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01688     ti->x + 1, ti->y, 1, 16, 4, ti->z);
01689 }
01690 
01691 static void DrawTrackFence_SW(const TileInfo *ti, SpriteID base_image)
01692 {
01693   RailFenceOffset rfo = RFO_FLAT_Y;
01694   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SE : RFO_SLOPE_NW;
01695   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01696     ti->x + TILE_SIZE - 1, ti->y, 1, 16, 4, ti->z);
01697 }
01698 
01699 static void DrawTrackFence_NE_SW(const TileInfo *ti, SpriteID base_image)
01700 {
01701   DrawTrackFence_NE(ti, base_image);
01702   DrawTrackFence_SW(ti, base_image);
01703 }
01704 
01708 static void DrawTrackFence_NS_1(const TileInfo *ti, SpriteID base_image)
01709 {
01710   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_W);
01711   AddSortableSpriteToDraw(base_image + RFO_FLAT_VERT, _drawtile_track_palette,
01712     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01713 }
01714 
01718 static void DrawTrackFence_NS_2(const TileInfo *ti, SpriteID base_image)
01719 {
01720   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_E);
01721   AddSortableSpriteToDraw(base_image + RFO_FLAT_VERT, _drawtile_track_palette,
01722     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01723 }
01724 
01728 static void DrawTrackFence_WE_1(const TileInfo *ti, SpriteID base_image)
01729 {
01730   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_N);
01731   AddSortableSpriteToDraw(base_image + RFO_FLAT_HORZ, _drawtile_track_palette,
01732     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01733 }
01734 
01738 static void DrawTrackFence_WE_2(const TileInfo *ti, SpriteID base_image)
01739 {
01740   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_S);
01741   AddSortableSpriteToDraw(base_image + RFO_FLAT_HORZ, _drawtile_track_palette,
01742     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01743 }
01744 
01745 
01746 static void DrawTrackDetails(const TileInfo *ti, const RailtypeInfo *rti)
01747 {
01748   /* Base sprite for track fences. */
01749   SpriteID base_image = GetCustomRailSprite(rti, ti->tile, RTSG_FENCES);
01750   if (base_image == 0) base_image = SPR_TRACK_FENCE_FLAT_X;
01751 
01752   switch (GetRailGroundType(ti->tile)) {
01753     case RAIL_GROUND_FENCE_NW:     DrawTrackFence_NW(ti, base_image);    break;
01754     case RAIL_GROUND_FENCE_SE:     DrawTrackFence_SE(ti, base_image);    break;
01755     case RAIL_GROUND_FENCE_SENW:   DrawTrackFence_NW_SE(ti, base_image); break;
01756     case RAIL_GROUND_FENCE_NE:     DrawTrackFence_NE(ti, base_image);    break;
01757     case RAIL_GROUND_FENCE_SW:     DrawTrackFence_SW(ti, base_image);    break;
01758     case RAIL_GROUND_FENCE_NESW:   DrawTrackFence_NE_SW(ti, base_image); break;
01759     case RAIL_GROUND_FENCE_VERT1:  DrawTrackFence_NS_1(ti, base_image);  break;
01760     case RAIL_GROUND_FENCE_VERT2:  DrawTrackFence_NS_2(ti, base_image);  break;
01761     case RAIL_GROUND_FENCE_HORIZ1: DrawTrackFence_WE_1(ti, base_image);  break;
01762     case RAIL_GROUND_FENCE_HORIZ2: DrawTrackFence_WE_2(ti, base_image);  break;
01763     case RAIL_GROUND_WATER: {
01764       Corner track_corner;
01765       if (IsHalftileSlope(ti->tileh)) {
01766         /* Steep slope or one-corner-raised slope with halftile foundation */
01767         track_corner = GetHalftileSlopeCorner(ti->tileh);
01768       } else {
01769         /* Three-corner-raised slope */
01770         track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
01771       }
01772       switch (track_corner) {
01773         case CORNER_W: DrawTrackFence_NS_1(ti, base_image); break;
01774         case CORNER_S: DrawTrackFence_WE_2(ti, base_image); break;
01775         case CORNER_E: DrawTrackFence_NS_2(ti, base_image); break;
01776         case CORNER_N: DrawTrackFence_WE_1(ti, base_image); break;
01777         default: NOT_REACHED();
01778       }
01779       break;
01780     }
01781     default: break;
01782   }
01783 }
01784 
01785 /* SubSprite for drawing the track halftile of 'three-corners-raised'-sloped rail sprites. */
01786 static const int INF = 1000; // big number compared to tilesprite size
01787 static const SubSprite _halftile_sub_sprite[4] = {
01788   { -INF    , -INF  , 32 - 33, INF     }, // CORNER_W, clip 33 pixels from right
01789   { -INF    ,  0 + 7, INF    , INF     }, // CORNER_S, clip 7 pixels from top
01790   { -31 + 33, -INF  , INF    , INF     }, // CORNER_E, clip 33 pixels from left
01791   { -INF    , -INF  , INF    , 30 - 23 }  // CORNER_N, clip 23 pixels from bottom
01792 };
01793 
01794 static inline void DrawTrackSprite(SpriteID sprite, PaletteID pal, const TileInfo *ti, Slope s)
01795 {
01796   DrawGroundSprite(sprite, pal, NULL, 0, (ti->tileh & s) ? -8 : 0);
01797 }
01798 
01799 static void DrawTrackBitsOverlay(TileInfo *ti, TrackBits track, const RailtypeInfo *rti)
01800 {
01801   RailGroundType rgt = GetRailGroundType(ti->tile);
01802   Foundation f = GetRailFoundation(ti->tileh, track);
01803   Corner halftile_corner = CORNER_INVALID;
01804 
01805   if (IsNonContinuousFoundation(f)) {
01806     /* Save halftile corner */
01807     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
01808     /* Draw lower part first */
01809     track &= ~CornerToTrackBits(halftile_corner);
01810     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
01811   }
01812 
01813   DrawFoundation(ti, f);
01814   /* DrawFoundation modifies ti */
01815 
01816   /* Draw ground */
01817   if (track == TRACK_BIT_NONE && rgt == RAIL_GROUND_WATER) {
01818     if (IsSteepSlope(ti->tileh)) {
01819       DrawShoreTile(ti->tileh);
01820     } else {
01821       DrawGroundSprite(SPR_FLAT_WATER_TILE, PAL_NONE);
01822     }
01823   } else {
01824     SpriteID image;
01825 
01826     switch (rgt) {
01827       case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
01828       case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOW_DESERT_TILE; break;
01829       default:                     image = SPR_FLAT_GRASS_TILE; break;
01830     }
01831 
01832     image += _tileh_to_sprite[ti->tileh];
01833 
01834     DrawGroundSprite(image, PAL_NONE);
01835   }
01836 
01837   SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
01838   SpriteID ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND);
01839   TrackBits pbs = _settings_client.gui.show_track_reservation ? GetRailReservationTrackBits(ti->tile) : TRACK_BIT_NONE;
01840 
01841   if (track == TRACK_BIT_NONE) {
01842     /* Half-tile foundation, no track here? */
01843   } else if (ti->tileh == SLOPE_NW && track == TRACK_BIT_Y) {
01844     DrawGroundSprite(ground + RTO_SLOPE_NW, PAL_NONE);
01845     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 9, PALETTE_CRASH);
01846   } else if (ti->tileh == SLOPE_NE && track == TRACK_BIT_X) {
01847     DrawGroundSprite(ground + RTO_SLOPE_NE, PAL_NONE);
01848     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 6, PALETTE_CRASH);
01849   } else if (ti->tileh == SLOPE_SE && track == TRACK_BIT_Y) {
01850     DrawGroundSprite(ground + RTO_SLOPE_SE, PAL_NONE);
01851     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 7, PALETTE_CRASH);
01852   } else if (ti->tileh == SLOPE_SW && track == TRACK_BIT_X) {
01853     DrawGroundSprite(ground + RTO_SLOPE_SW, PAL_NONE);
01854     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 8, PALETTE_CRASH);
01855   } else {
01856     switch (track) {
01857       /* Draw single ground sprite when not overlapping. No track overlay
01858        * is necessary for these sprites. */
01859       case TRACK_BIT_X:     DrawGroundSprite(ground + RTO_X, PAL_NONE); break;
01860       case TRACK_BIT_Y:     DrawGroundSprite(ground + RTO_Y, PAL_NONE); break;
01861       case TRACK_BIT_UPPER: DrawTrackSprite(ground + RTO_N, PAL_NONE, ti, SLOPE_N); break;
01862       case TRACK_BIT_LOWER: DrawTrackSprite(ground + RTO_S, PAL_NONE, ti, SLOPE_S); break;
01863       case TRACK_BIT_RIGHT: DrawTrackSprite(ground + RTO_E, PAL_NONE, ti, SLOPE_E); break;
01864       case TRACK_BIT_LEFT:  DrawTrackSprite(ground + RTO_W, PAL_NONE, ti, SLOPE_W); break;
01865       case TRACK_BIT_CROSS: DrawGroundSprite(ground + RTO_CROSSING_XY, PAL_NONE); break;
01866       case TRACK_BIT_HORZ:  DrawTrackSprite(ground + RTO_N, PAL_NONE, ti, SLOPE_N);
01867                             DrawTrackSprite(ground + RTO_S, PAL_NONE, ti, SLOPE_S); break;
01868       case TRACK_BIT_VERT:  DrawTrackSprite(ground + RTO_E, PAL_NONE, ti, SLOPE_E);
01869                             DrawTrackSprite(ground + RTO_W, PAL_NONE, ti, SLOPE_W); break;
01870 
01871       default:
01872         /* We're drawing a junction tile */
01873         if ((track & TRACK_BIT_3WAY_NE) == 0) {
01874           DrawGroundSprite(ground + RTO_JUNCTION_SW, PAL_NONE);
01875         } else if ((track & TRACK_BIT_3WAY_SW) == 0) {
01876           DrawGroundSprite(ground + RTO_JUNCTION_NE, PAL_NONE);
01877         } else if ((track & TRACK_BIT_3WAY_NW) == 0) {
01878           DrawGroundSprite(ground + RTO_JUNCTION_SE, PAL_NONE);
01879         } else if ((track & TRACK_BIT_3WAY_SE) == 0) {
01880           DrawGroundSprite(ground + RTO_JUNCTION_NW, PAL_NONE);
01881         } else {
01882           DrawGroundSprite(ground + RTO_JUNCTION_NSEW, PAL_NONE);
01883         }
01884 
01885         /* Mask out PBS bits as we shall draw them afterwards anyway. */
01886         track &= ~pbs;
01887 
01888         /* Draw regular track bits */
01889         if (track & TRACK_BIT_X)     DrawGroundSprite(overlay + RTO_X, PAL_NONE);
01890         if (track & TRACK_BIT_Y)     DrawGroundSprite(overlay + RTO_Y, PAL_NONE);
01891         if (track & TRACK_BIT_UPPER) DrawGroundSprite(overlay + RTO_N, PAL_NONE);
01892         if (track & TRACK_BIT_LOWER) DrawGroundSprite(overlay + RTO_S, PAL_NONE);
01893         if (track & TRACK_BIT_RIGHT) DrawGroundSprite(overlay + RTO_E, PAL_NONE);
01894         if (track & TRACK_BIT_LEFT)  DrawGroundSprite(overlay + RTO_W, PAL_NONE);
01895     }
01896 
01897     /* Draw reserved track bits */
01898     if (pbs & TRACK_BIT_X)     DrawGroundSprite(overlay + RTO_X, PALETTE_CRASH);
01899     if (pbs & TRACK_BIT_Y)     DrawGroundSprite(overlay + RTO_Y, PALETTE_CRASH);
01900     if (pbs & TRACK_BIT_UPPER) DrawTrackSprite(overlay + RTO_N, PALETTE_CRASH, ti, SLOPE_N);
01901     if (pbs & TRACK_BIT_LOWER) DrawTrackSprite(overlay + RTO_S, PALETTE_CRASH, ti, SLOPE_S);
01902     if (pbs & TRACK_BIT_RIGHT) DrawTrackSprite(overlay + RTO_E, PALETTE_CRASH, ti, SLOPE_E);
01903     if (pbs & TRACK_BIT_LEFT)  DrawTrackSprite(overlay + RTO_W, PALETTE_CRASH, ti, SLOPE_W);
01904   }
01905 
01906   if (IsValidCorner(halftile_corner)) {
01907     DrawFoundation(ti, HalftileFoundation(halftile_corner));
01908 
01909     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
01910     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
01911 
01912     SpriteID image;
01913     switch (rgt) {
01914       case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
01915       case RAIL_GROUND_ICE_DESERT:
01916       case RAIL_GROUND_HALF_SNOW:  image = SPR_FLAT_SNOW_DESERT_TILE; break;
01917       default:                     image = SPR_FLAT_GRASS_TILE; break;
01918     }
01919 
01920     image += _tileh_to_sprite[fake_slope];
01921 
01922     DrawGroundSprite(image, PAL_NONE, &(_halftile_sub_sprite[halftile_corner]));
01923 
01924     track = CornerToTrackBits(halftile_corner);
01925 
01926     int offset;
01927     switch (track) {
01928       default: NOT_REACHED();
01929       case TRACK_BIT_UPPER: offset = RTO_N; break;
01930       case TRACK_BIT_LOWER: offset = RTO_S; break;
01931       case TRACK_BIT_RIGHT: offset = RTO_E; break;
01932       case TRACK_BIT_LEFT:  offset = RTO_W; break;
01933     }
01934 
01935     DrawTrackSprite(ground + offset, PAL_NONE, ti, fake_slope);
01936     if (HasReservedTracks(ti->tile, track)) {
01937       DrawTrackSprite(overlay + offset, PALETTE_CRASH, ti, fake_slope);
01938     }
01939   }
01940 }
01941 
01947 static void DrawTrackBits(TileInfo *ti, TrackBits track)
01948 {
01949   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
01950 
01951   if (rti->UsesOverlay()) {
01952     DrawTrackBitsOverlay(ti, track, rti);
01953     return;
01954   }
01955 
01956   RailGroundType rgt = GetRailGroundType(ti->tile);
01957   Foundation f = GetRailFoundation(ti->tileh, track);
01958   Corner halftile_corner = CORNER_INVALID;
01959 
01960   if (IsNonContinuousFoundation(f)) {
01961     /* Save halftile corner */
01962     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
01963     /* Draw lower part first */
01964     track &= ~CornerToTrackBits(halftile_corner);
01965     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
01966   }
01967 
01968   DrawFoundation(ti, f);
01969   /* DrawFoundation modifies ti */
01970 
01971   SpriteID image;
01972   PaletteID pal = PAL_NONE;
01973   const SubSprite *sub = NULL;
01974   bool junction = false;
01975 
01976   /* Select the sprite to use. */
01977   if (track == 0) {
01978     /* Clear ground (only track on halftile foundation) */
01979     if (rgt == RAIL_GROUND_WATER) {
01980       if (IsSteepSlope(ti->tileh)) {
01981         DrawShoreTile(ti->tileh);
01982         image = 0;
01983       } else {
01984         image = SPR_FLAT_WATER_TILE;
01985       }
01986     } else {
01987       switch (rgt) {
01988         case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
01989         case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOW_DESERT_TILE; break;
01990         default:                     image = SPR_FLAT_GRASS_TILE; break;
01991       }
01992       image += _tileh_to_sprite[ti->tileh];
01993     }
01994   } else {
01995     if (ti->tileh != SLOPE_FLAT) {
01996       /* track on non-flat ground */
01997       image = _track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.track_y;
01998     } else {
01999       /* track on flat ground */
02000       (image = rti->base_sprites.track_y, track == TRACK_BIT_Y) ||
02001       (image++,                           track == TRACK_BIT_X) ||
02002       (image++,                           track == TRACK_BIT_UPPER) ||
02003       (image++,                           track == TRACK_BIT_LOWER) ||
02004       (image++,                           track == TRACK_BIT_RIGHT) ||
02005       (image++,                           track == TRACK_BIT_LEFT) ||
02006       (image++,                           track == TRACK_BIT_CROSS) ||
02007 
02008       (image = rti->base_sprites.track_ns, track == TRACK_BIT_HORZ) ||
02009       (image++,                            track == TRACK_BIT_VERT) ||
02010 
02011       (junction = true, false) ||
02012       (image = rti->base_sprites.ground, (track & TRACK_BIT_3WAY_NE) == 0) ||
02013       (image++,                          (track & TRACK_BIT_3WAY_SW) == 0) ||
02014       (image++,                          (track & TRACK_BIT_3WAY_NW) == 0) ||
02015       (image++,                          (track & TRACK_BIT_3WAY_SE) == 0) ||
02016       (image++, true);
02017     }
02018 
02019     switch (rgt) {
02020       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
02021       case RAIL_GROUND_ICE_DESERT: image += rti->snow_offset;  break;
02022       case RAIL_GROUND_WATER: {
02023         /* three-corner-raised slope */
02024         DrawShoreTile(ti->tileh);
02025         Corner track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
02026         sub = &(_halftile_sub_sprite[track_corner]);
02027         break;
02028       }
02029       default: break;
02030     }
02031   }
02032 
02033   if (image != 0) DrawGroundSprite(image, pal, sub);
02034 
02035   /* Draw track pieces individually for junction tiles */
02036   if (junction) {
02037     if (track & TRACK_BIT_X)     DrawGroundSprite(rti->base_sprites.single_x, PAL_NONE);
02038     if (track & TRACK_BIT_Y)     DrawGroundSprite(rti->base_sprites.single_y, PAL_NONE);
02039     if (track & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PAL_NONE);
02040     if (track & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PAL_NONE);
02041     if (track & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PAL_NONE);
02042     if (track & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PAL_NONE);
02043   }
02044 
02045   /* PBS debugging, draw reserved tracks darker */
02046   if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation) {
02047     /* Get reservation, but mask track on halftile slope */
02048     TrackBits pbs = GetRailReservationTrackBits(ti->tile) & track;
02049     if (pbs & TRACK_BIT_X) {
02050       if (ti->tileh == SLOPE_FLAT || ti->tileh == SLOPE_ELEVATED) {
02051         DrawGroundSprite(rti->base_sprites.single_x, PALETTE_CRASH);
02052       } else {
02053         DrawGroundSprite(_track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.single_sloped - 20, PALETTE_CRASH);
02054       }
02055     }
02056     if (pbs & TRACK_BIT_Y) {
02057       if (ti->tileh == SLOPE_FLAT || ti->tileh == SLOPE_ELEVATED) {
02058         DrawGroundSprite(rti->base_sprites.single_y, PALETTE_CRASH);
02059       } else {
02060         DrawGroundSprite(_track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.single_sloped - 20, PALETTE_CRASH);
02061       }
02062     }
02063     if (pbs & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_N ? -TILE_HEIGHT : 0);
02064     if (pbs & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_S ? -TILE_HEIGHT : 0);
02065     if (pbs & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_W ? -TILE_HEIGHT : 0);
02066     if (pbs & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_E ? -TILE_HEIGHT : 0);
02067   }
02068 
02069   if (IsValidCorner(halftile_corner)) {
02070     DrawFoundation(ti, HalftileFoundation(halftile_corner));
02071 
02072     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
02073     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
02074     image = _track_sloped_sprites[fake_slope - 1] + rti->base_sprites.track_y;
02075     pal = PAL_NONE;
02076     switch (rgt) {
02077       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
02078       case RAIL_GROUND_ICE_DESERT:
02079       case RAIL_GROUND_HALF_SNOW:  image += rti->snow_offset;  break; // higher part has snow in this case too
02080       default: break;
02081     }
02082     DrawGroundSprite(image, pal, &(_halftile_sub_sprite[halftile_corner]));
02083 
02084     if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasReservedTracks(ti->tile, CornerToTrackBits(halftile_corner))) {
02085       static const byte _corner_to_track_sprite[] = {3, 1, 2, 0};
02086       DrawGroundSprite(_corner_to_track_sprite[halftile_corner] + rti->base_sprites.single_n, PALETTE_CRASH, NULL, 0, -TILE_HEIGHT);
02087     }
02088   }
02089 }
02090 
02096 enum {
02097   SIGNAL_TO_SOUTHWEST =  0,
02098   SIGNAL_TO_NORTHEAST =  2,
02099   SIGNAL_TO_SOUTHEAST =  4,
02100   SIGNAL_TO_NORTHWEST =  6,
02101   SIGNAL_TO_EAST      =  8,
02102   SIGNAL_TO_WEST      = 10,
02103   SIGNAL_TO_SOUTH     = 12,
02104   SIGNAL_TO_NORTH     = 14,
02105 };
02106 
02107 static void DrawSignals(TileIndex tile, TrackBits rails)
02108 {
02109 #define MAYBE_DRAW_SIGNAL(x, y, z, t) if (IsSignalPresent(tile, x)) DrawSingleSignal(tile, t, GetSingleSignalState(tile, x), y, z)
02110 
02111   if (!(rails & TRACK_BIT_Y)) {
02112     if (!(rails & TRACK_BIT_X)) {
02113       if (rails & TRACK_BIT_LEFT) {
02114         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTH, 0, TRACK_LEFT);
02115         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTH, 1, TRACK_LEFT);
02116       }
02117       if (rails & TRACK_BIT_RIGHT) {
02118         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_NORTH, 2, TRACK_RIGHT);
02119         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_SOUTH, 3, TRACK_RIGHT);
02120       }
02121       if (rails & TRACK_BIT_UPPER) {
02122         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_WEST, 4, TRACK_UPPER);
02123         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_EAST, 5, TRACK_UPPER);
02124       }
02125       if (rails & TRACK_BIT_LOWER) {
02126         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_WEST, 6, TRACK_LOWER);
02127         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_EAST, 7, TRACK_LOWER);
02128       }
02129     } else {
02130       MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHWEST, 8, TRACK_X);
02131       MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHEAST, 9, TRACK_X);
02132     }
02133   } else {
02134     MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHEAST, 10, TRACK_Y);
02135     MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHWEST, 11, TRACK_Y);
02136   }
02137 }
02138 
02139 static void DrawTile_Track(TileInfo *ti)
02140 {
02141   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
02142 
02143   _drawtile_track_palette = COMPANY_SPRITE_COLOUR(GetTileOwner(ti->tile));
02144 
02145   if (IsPlainRail(ti->tile)) {
02146     TrackBits rails = GetTrackBits(ti->tile);
02147 
02148     DrawTrackBits(ti, rails);
02149 
02150     if (HasBit(_display_opt, DO_FULL_DETAIL)) DrawTrackDetails(ti, rti);
02151 
02152     if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
02153 
02154     if (HasSignals(ti->tile)) DrawSignals(ti->tile, rails);
02155   } else {
02156     /* draw depot */
02157     const DrawTileSprites *dts;
02158     PaletteID pal = PAL_NONE;
02159     SpriteID relocation;
02160 
02161     if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);
02162 
02163     if (IsInvisibilitySet(TO_BUILDINGS)) {
02164       /* Draw rail instead of depot */
02165       dts = &_depot_invisible_gfx_table[GetRailDepotDirection(ti->tile)];
02166     } else {
02167       dts = &_depot_gfx_table[GetRailDepotDirection(ti->tile)];
02168     }
02169 
02170     SpriteID image;
02171     if (rti->UsesOverlay()) {
02172       image = SPR_FLAT_GRASS_TILE;
02173     } else {
02174       image = dts->ground.sprite;
02175       if (image != SPR_FLAT_GRASS_TILE) image += rti->total_offset;
02176     }
02177 
02178     /* adjust ground tile for desert
02179      * don't adjust for snow, because snow in depots looks weird */
02180     if (IsSnowRailGround(ti->tile) && _settings_game.game_creation.landscape == LT_TROPIC) {
02181       if (image != SPR_FLAT_GRASS_TILE) {
02182         image += rti->snow_offset; // tile with tracks
02183       } else {
02184         image = SPR_FLAT_SNOW_DESERT_TILE; // flat ground
02185       }
02186     }
02187 
02188     DrawGroundSprite(image, GroundSpritePaletteTransform(image, pal, _drawtile_track_palette));
02189 
02190     if (rti->UsesOverlay()) {
02191       SpriteID ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND);
02192 
02193       switch (GetRailDepotDirection(ti->tile)) {
02194         case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02195         case DIAGDIR_SW: DrawGroundSprite(ground + RTO_X, PAL_NONE); break;
02196         case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02197         case DIAGDIR_SE: DrawGroundSprite(ground + RTO_Y, PAL_NONE); break;
02198         default: break;
02199       }
02200 
02201       if (_settings_client.gui.show_track_reservation && HasDepotReservation(ti->tile)) {
02202         SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
02203 
02204         switch (GetRailDepotDirection(ti->tile)) {
02205           case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02206           case DIAGDIR_SW: DrawGroundSprite(overlay + RTO_X, PALETTE_CRASH); break;
02207           case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02208           case DIAGDIR_SE: DrawGroundSprite(overlay + RTO_Y, PALETTE_CRASH); break;
02209           default: break;
02210         }
02211       }
02212 
02213       relocation  = GetCustomRailSprite(rti, ti->tile, RTSG_DEPOT);
02214       relocation -= SPR_RAIL_DEPOT_SE_1;
02215     } else {
02216       /* PBS debugging, draw reserved tracks darker */
02217       if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasDepotReservation(ti->tile)) {
02218         switch (GetRailDepotDirection(ti->tile)) {
02219           case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02220           case DIAGDIR_SW: DrawGroundSprite(rti->base_sprites.single_x, PALETTE_CRASH); break;
02221           case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02222           case DIAGDIR_SE: DrawGroundSprite(rti->base_sprites.single_y, PALETTE_CRASH); break;
02223           default: break;
02224         }
02225       }
02226 
02227       relocation = rti->total_offset;
02228     }
02229 
02230     if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
02231 
02232     DrawRailTileSeq(ti, dts, TO_BUILDINGS, relocation, 0, _drawtile_track_palette);
02233   }
02234   DrawBridgeMiddle(ti);
02235 }
02236 
02237 void DrawTrainDepotSprite(int x, int y, int dir, RailType railtype)
02238 {
02239   const DrawTileSprites *dts = &_depot_gfx_table[dir];
02240   const RailtypeInfo *rti = GetRailTypeInfo(railtype);
02241   SpriteID image = rti->UsesOverlay() ? SPR_FLAT_GRASS_TILE : dts->ground.sprite;
02242   uint32 offset = rti->total_offset;
02243 
02244   x += 33;
02245   y += 17;
02246 
02247   if (image != SPR_FLAT_GRASS_TILE) image += offset;
02248   PaletteID palette = COMPANY_SPRITE_COLOUR(_local_company);
02249 
02250   DrawSprite(image, PAL_NONE, x, y);
02251 
02252   if (rti->UsesOverlay()) {
02253     SpriteID ground = GetCustomRailSprite(rti, INVALID_TILE, RTSG_GROUND);
02254 
02255     switch (dir) {
02256       case DIAGDIR_SW: DrawSprite(ground + RTO_X, PAL_NONE, x, y); break;
02257       case DIAGDIR_SE: DrawSprite(ground + RTO_Y, PAL_NONE, x, y); break;
02258       default: break;
02259     }
02260 
02261     offset  = GetCustomRailSprite(rti, INVALID_TILE, RTSG_DEPOT);
02262     offset -= SPR_RAIL_DEPOT_SE_1;
02263   }
02264 
02265   DrawRailTileSeqInGUI(x, y, dts, offset, 0, palette);
02266 }
02267 
02268 static uint GetSlopeZ_Track(TileIndex tile, uint x, uint y)
02269 {
02270   uint z;
02271   Slope tileh = GetTileSlope(tile, &z);
02272 
02273   if (tileh == SLOPE_FLAT) return z;
02274   if (IsPlainRail(tile)) {
02275     z += ApplyFoundationToSlope(GetRailFoundation(tileh, GetTrackBits(tile)), &tileh);
02276     return z + GetPartialZ(x & 0xF, y & 0xF, tileh);
02277   } else {
02278     return z + TILE_HEIGHT;
02279   }
02280 }
02281 
02282 static Foundation GetFoundation_Track(TileIndex tile, Slope tileh)
02283 {
02284   return IsPlainRail(tile) ? GetRailFoundation(tileh, GetTrackBits(tile)) : FlatteningFoundation(tileh);
02285 }
02286 
02287 static void TileLoop_Track(TileIndex tile)
02288 {
02289   RailGroundType old_ground = GetRailGroundType(tile);
02290   RailGroundType new_ground;
02291 
02292   if (old_ground == RAIL_GROUND_WATER) {
02293     TileLoop_Water(tile);
02294     return;
02295   }
02296 
02297   switch (_settings_game.game_creation.landscape) {
02298     case LT_ARCTIC: {
02299       uint z;
02300       Slope slope = GetTileSlope(tile, &z);
02301       bool half = false;
02302 
02303       /* for non-flat track, use lower part of track
02304        * in other cases, use the highest part with track */
02305       if (IsPlainRail(tile)) {
02306         TrackBits track = GetTrackBits(tile);
02307         Foundation f = GetRailFoundation(slope, track);
02308 
02309         switch (f) {
02310           case FOUNDATION_NONE:
02311             /* no foundation - is the track on the upper side of three corners raised tile? */
02312             if (IsSlopeWithThreeCornersRaised(slope)) z += TILE_HEIGHT;
02313             break;
02314 
02315           case FOUNDATION_INCLINED_X:
02316           case FOUNDATION_INCLINED_Y:
02317             /* sloped track - is it on a steep slope? */
02318             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
02319             break;
02320 
02321           case FOUNDATION_STEEP_LOWER:
02322             /* only lower part of steep slope */
02323             z += TILE_HEIGHT;
02324             break;
02325 
02326           default:
02327             /* if it is a steep slope, then there is a track on higher part */
02328             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
02329             z += TILE_HEIGHT;
02330             break;
02331         }
02332 
02333         half = IsInsideMM(f, FOUNDATION_STEEP_BOTH, FOUNDATION_HALFTILE_N + 1);
02334       } else {
02335         /* is the depot on a non-flat tile? */
02336         if (slope != SLOPE_FLAT) z += TILE_HEIGHT;
02337       }
02338 
02339       /* 'z' is now the lowest part of the highest track bit -
02340        * for sloped track, it is 'z' of lower part
02341        * for two track bits, it is 'z' of higher track bit
02342        * For non-continuous foundations (and STEEP_BOTH), 'half' is set */
02343       if (z > GetSnowLine()) {
02344         if (half && z - GetSnowLine() == TILE_HEIGHT) {
02345           /* track on non-continuous foundation, lower part is not under snow */
02346           new_ground = RAIL_GROUND_HALF_SNOW;
02347         } else {
02348           new_ground = RAIL_GROUND_ICE_DESERT;
02349         }
02350         goto set_ground;
02351       }
02352       break;
02353       }
02354 
02355     case LT_TROPIC:
02356       if (GetTropicZone(tile) == TROPICZONE_DESERT) {
02357         new_ground = RAIL_GROUND_ICE_DESERT;
02358         goto set_ground;
02359       }
02360       break;
02361   }
02362 
02363   if (!IsPlainRail(tile)) return;
02364 
02365   new_ground = RAIL_GROUND_GRASS;
02366 
02367   if (old_ground != RAIL_GROUND_BARREN) { // wait until bottom is green
02368     /* determine direction of fence */
02369     TrackBits rail = GetTrackBits(tile);
02370 
02371     switch (rail) {
02372       case TRACK_BIT_UPPER: new_ground = RAIL_GROUND_FENCE_HORIZ1; break;
02373       case TRACK_BIT_LOWER: new_ground = RAIL_GROUND_FENCE_HORIZ2; break;
02374       case TRACK_BIT_LEFT:  new_ground = RAIL_GROUND_FENCE_VERT1;  break;
02375       case TRACK_BIT_RIGHT: new_ground = RAIL_GROUND_FENCE_VERT2;  break;
02376 
02377       default: {
02378         Owner owner = GetTileOwner(tile);
02379 
02380         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_RIGHT) || (
02381               (rail & TRACK_BIT_3WAY_NW) == 0 &&
02382               (rail & TRACK_BIT_X)
02383             )) {
02384           TileIndex n = tile + TileDiffXY(0, -1);
02385           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02386 
02387           if (!IsTileType(n, MP_RAILWAY) ||
02388               !IsTileOwner(n, owner) ||
02389               nrail == TRACK_BIT_UPPER ||
02390               nrail == TRACK_BIT_LEFT) {
02391             new_ground = RAIL_GROUND_FENCE_NW;
02392           }
02393         }
02394 
02395         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_LEFT) || (
02396               (rail & TRACK_BIT_3WAY_SE) == 0 &&
02397               (rail & TRACK_BIT_X)
02398             )) {
02399           TileIndex n = tile + TileDiffXY(0, 1);
02400           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02401 
02402           if (!IsTileType(n, MP_RAILWAY) ||
02403               !IsTileOwner(n, owner) ||
02404               nrail == TRACK_BIT_LOWER ||
02405               nrail == TRACK_BIT_RIGHT) {
02406             new_ground = (new_ground == RAIL_GROUND_FENCE_NW) ?
02407               RAIL_GROUND_FENCE_SENW : RAIL_GROUND_FENCE_SE;
02408           }
02409         }
02410 
02411         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_LEFT) || (
02412               (rail & TRACK_BIT_3WAY_NE) == 0 &&
02413               (rail & TRACK_BIT_Y)
02414             )) {
02415           TileIndex n = tile + TileDiffXY(-1, 0);
02416           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02417 
02418           if (!IsTileType(n, MP_RAILWAY) ||
02419               !IsTileOwner(n, owner) ||
02420               nrail == TRACK_BIT_UPPER ||
02421               nrail == TRACK_BIT_RIGHT) {
02422             new_ground = RAIL_GROUND_FENCE_NE;
02423           }
02424         }
02425 
02426         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_RIGHT) || (
02427               (rail & TRACK_BIT_3WAY_SW) == 0 &&
02428               (rail & TRACK_BIT_Y)
02429             )) {
02430           TileIndex n = tile + TileDiffXY(1, 0);
02431           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02432 
02433           if (!IsTileType(n, MP_RAILWAY) ||
02434               !IsTileOwner(n, owner) ||
02435               nrail == TRACK_BIT_LOWER ||
02436               nrail == TRACK_BIT_LEFT) {
02437             new_ground = (new_ground == RAIL_GROUND_FENCE_NE) ?
02438               RAIL_GROUND_FENCE_NESW : RAIL_GROUND_FENCE_SW;
02439           }
02440         }
02441         break;
02442       }
02443     }
02444   }
02445 
02446 set_ground:
02447   if (old_ground != new_ground) {
02448     SetRailGroundType(tile, new_ground);
02449     MarkTileDirtyByTile(tile);
02450   }
02451 }
02452 
02453 
02454 static TrackStatus GetTileTrackStatus_Track(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
02455 {
02456   /* Case of half tile slope with water. */
02457   if (mode == TRANSPORT_WATER && IsPlainRail(tile) && GetRailGroundType(tile) == RAIL_GROUND_WATER) {
02458     TrackBits tb = GetTrackBits(tile);
02459     switch (tb) {
02460       default: NOT_REACHED();
02461       case TRACK_BIT_UPPER: tb = TRACK_BIT_LOWER; break;
02462       case TRACK_BIT_LOWER: tb = TRACK_BIT_UPPER; break;
02463       case TRACK_BIT_LEFT:  tb = TRACK_BIT_RIGHT; break;
02464       case TRACK_BIT_RIGHT: tb = TRACK_BIT_LEFT;  break;
02465     }
02466     return CombineTrackStatus(TrackBitsToTrackdirBits(tb), TRACKDIR_BIT_NONE);
02467   }
02468 
02469   if (mode != TRANSPORT_RAIL) return 0;
02470 
02471   TrackBits trackbits = TRACK_BIT_NONE;
02472   TrackdirBits red_signals = TRACKDIR_BIT_NONE;
02473 
02474   switch (GetRailTileType(tile)) {
02475     default: NOT_REACHED();
02476     case RAIL_TILE_NORMAL:
02477       trackbits = GetTrackBits(tile);
02478       break;
02479 
02480     case RAIL_TILE_SIGNALS: {
02481       trackbits = GetTrackBits(tile);
02482       byte a = GetPresentSignals(tile);
02483       uint b = GetSignalStates(tile);
02484 
02485       b &= a;
02486 
02487       /* When signals are not present (in neither direction),
02488        * we pretend them to be green. Otherwise, it depends on
02489        * the signal type. For signals that are only active from
02490        * one side, we set the missing signals explicitely to
02491        * `green'. Otherwise, they implicitely become `red'. */
02492       if (!IsOnewaySignal(tile, TRACK_UPPER) || (a & SignalOnTrack(TRACK_UPPER)) == 0) b |= ~a & SignalOnTrack(TRACK_UPPER);
02493       if (!IsOnewaySignal(tile, TRACK_LOWER) || (a & SignalOnTrack(TRACK_LOWER)) == 0) b |= ~a & SignalOnTrack(TRACK_LOWER);
02494 
02495       if ((b & 0x8) == 0) red_signals |= (TRACKDIR_BIT_LEFT_N | TRACKDIR_BIT_X_NE | TRACKDIR_BIT_Y_SE | TRACKDIR_BIT_UPPER_E);
02496       if ((b & 0x4) == 0) red_signals |= (TRACKDIR_BIT_LEFT_S | TRACKDIR_BIT_X_SW | TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_UPPER_W);
02497       if ((b & 0x2) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_N | TRACKDIR_BIT_LOWER_E);
02498       if ((b & 0x1) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_S | TRACKDIR_BIT_LOWER_W);
02499 
02500       break;
02501     }
02502 
02503     case RAIL_TILE_DEPOT: {
02504       DiagDirection dir = GetRailDepotDirection(tile);
02505 
02506       if (side != INVALID_DIAGDIR && side != dir) break;
02507 
02508       trackbits = DiagDirToDiagTrackBits(dir);
02509       break;
02510     }
02511   }
02512 
02513   return CombineTrackStatus(TrackBitsToTrackdirBits(trackbits), red_signals);
02514 }
02515 
02516 static bool ClickTile_Track(TileIndex tile)
02517 {
02518   if (!IsRailDepot(tile)) return false;
02519 
02520   ShowDepotWindow(tile, VEH_TRAIN);
02521   return true;
02522 }
02523 
02524 static void GetTileDesc_Track(TileIndex tile, TileDesc *td)
02525 {
02526   td->owner[0] = GetTileOwner(tile);
02527   switch (GetRailTileType(tile)) {
02528     case RAIL_TILE_NORMAL:
02529       td->str = STR_LAI_RAIL_DESCRIPTION_TRACK;
02530       break;
02531 
02532     case RAIL_TILE_SIGNALS: {
02533       static const StringID signal_type[6][6] = {
02534         {
02535           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SIGNALS,
02536           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
02537           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_EXITSIGNALS,
02538           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_COMBOSIGNALS,
02539           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PBSSIGNALS,
02540           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_NOENTRYSIGNALS
02541         },
02542         {
02543           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
02544           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRESIGNALS,
02545           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_EXITSIGNALS,
02546           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_COMBOSIGNALS,
02547           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PBSSIGNALS,
02548           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_NOENTRYSIGNALS
02549         },
02550         {
02551           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_EXITSIGNALS,
02552           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_EXITSIGNALS,
02553           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXITSIGNALS,
02554           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_COMBOSIGNALS,
02555           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PBSSIGNALS,
02556           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_NOENTRYSIGNALS
02557         },
02558         {
02559           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_COMBOSIGNALS,
02560           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_COMBOSIGNALS,
02561           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_COMBOSIGNALS,
02562           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBOSIGNALS,
02563           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PBSSIGNALS,
02564           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS
02565         },
02566         {
02567           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PBSSIGNALS,
02568           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PBSSIGNALS,
02569           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PBSSIGNALS,
02570           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PBSSIGNALS,
02571           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBSSIGNALS,
02572           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS
02573         },
02574         {
02575           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_NOENTRYSIGNALS,
02576           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_NOENTRYSIGNALS,
02577           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_NOENTRYSIGNALS,
02578           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS,
02579           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS,
02580           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRYSIGNALS
02581         }
02582       };
02583 
02584       SignalType primary_signal;
02585       SignalType secondary_signal;
02586       if (HasSignalOnTrack(tile, TRACK_UPPER)) {
02587         primary_signal = GetSignalType(tile, TRACK_UPPER);
02588         secondary_signal = HasSignalOnTrack(tile, TRACK_LOWER) ? GetSignalType(tile, TRACK_LOWER) : primary_signal;
02589       } else {
02590         secondary_signal = primary_signal = GetSignalType(tile, TRACK_LOWER);
02591       }
02592 
02593       td->str = signal_type[secondary_signal][primary_signal];
02594       break;
02595     }
02596 
02597     case RAIL_TILE_DEPOT:
02598       td->str = STR_LAI_RAIL_DESCRIPTION_TRAIN_DEPOT;
02599       break;
02600 
02601     default:
02602       NOT_REACHED();
02603   }
02604 }
02605 
02606 static void ChangeTileOwner_Track(TileIndex tile, Owner old_owner, Owner new_owner)
02607 {
02608   if (!IsTileOwner(tile, old_owner)) return;
02609 
02610   if (new_owner != INVALID_OWNER) {
02611     SetTileOwner(tile, new_owner);
02612   } else {
02613     DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR);
02614   }
02615 }
02616 
02617 static const byte _fractcoords_behind[4] = { 0x8F, 0x8, 0x80, 0xF8 };
02618 static const byte _fractcoords_enter[4] = { 0x8A, 0x48, 0x84, 0xA8 };
02619 static const int8 _deltacoord_leaveoffset[8] = {
02620   -1,  0,  1,  0, /* x */
02621    0,  1,  0, -1  /* y */
02622 };
02623 
02624 
02630 int TicksToLeaveDepot(const Train *v)
02631 {
02632   DiagDirection dir = GetRailDepotDirection(v->tile);
02633   int length = v->tcache.cached_veh_length;
02634 
02635   switch (dir) {
02636     case DIAGDIR_NE: return  ((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) - (length + 1)));
02637     case DIAGDIR_SE: return -((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   + (length + 1)));
02638     case DIAGDIR_SW: return -((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) + (length + 1)));
02639     default:
02640     case DIAGDIR_NW: return  ((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   - (length + 1)));
02641   }
02642 
02643   return 0; // make compilers happy
02644 }
02645 
02648 static VehicleEnterTileStatus VehicleEnter_Track(Vehicle *u, TileIndex tile, int x, int y)
02649 {
02650   /* this routine applies only to trains in depot tiles */
02651   if (u->type != VEH_TRAIN || !IsRailDepotTile(tile)) return VETSB_CONTINUE;
02652 
02653   Train *v = Train::From(u);
02654 
02655   /* depot direction */
02656   DiagDirection dir = GetRailDepotDirection(tile);
02657 
02658   /* calculate the point where the following wagon should be activated
02659    * this depends on the length of the current vehicle */
02660   int length = v->tcache.cached_veh_length;
02661 
02662   byte fract_coord_leave =
02663     ((_fractcoords_enter[dir] & 0x0F) + // x
02664       (length + 1) * _deltacoord_leaveoffset[dir]) +
02665     (((_fractcoords_enter[dir] >> 4) +  // y
02666       ((length + 1) * _deltacoord_leaveoffset[dir + 4])) << 4);
02667 
02668   byte fract_coord = (x & 0xF) + ((y & 0xF) << 4);
02669 
02670   if (_fractcoords_behind[dir] == fract_coord) {
02671     /* make sure a train is not entering the tile from behind */
02672     return VETSB_CANNOT_ENTER;
02673   } else if (_fractcoords_enter[dir] == fract_coord) {
02674     if (DiagDirToDir(ReverseDiagDir(dir)) == v->direction) {
02675       /* enter the depot */
02676       v->track = TRACK_BIT_DEPOT,
02677       v->vehstatus |= VS_HIDDEN; // hide it
02678       v->direction = ReverseDir(v->direction);
02679       if (v->Next() == NULL) VehicleEnterDepot(v->First());
02680       v->tile = tile;
02681 
02682       InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02683       return VETSB_ENTERED_WORMHOLE;
02684     }
02685   } else if (fract_coord_leave == fract_coord) {
02686     if (DiagDirToDir(dir) == v->direction) {
02687       /* leave the depot? */
02688       if ((v = v->Next()) != NULL) {
02689         v->vehstatus &= ~VS_HIDDEN;
02690         v->track = (DiagDirToAxis(dir) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y);
02691       }
02692     }
02693   }
02694 
02695   return VETSB_CONTINUE;
02696 }
02697 
02709 static CommandCost TestAutoslopeOnRailTile(TileIndex tile, uint flags, uint z_old, Slope tileh_old, uint z_new, Slope tileh_new, TrackBits rail_bits)
02710 {
02711   if (!_settings_game.construction.build_on_slopes || !AutoslopeEnabled()) return CMD_ERROR;
02712 
02713   /* Is the slope-rail_bits combination valid in general? I.e. is it safe to call GetRailFoundation() ? */
02714   if (CheckRailSlope(tileh_new, rail_bits, TRACK_BIT_NONE, tile).Failed()) return CMD_ERROR;
02715 
02716   /* Get the slopes on top of the foundations */
02717   z_old += ApplyFoundationToSlope(GetRailFoundation(tileh_old, rail_bits), &tileh_old);
02718   z_new += ApplyFoundationToSlope(GetRailFoundation(tileh_new, rail_bits), &tileh_new);
02719 
02720   Corner track_corner;
02721   switch (rail_bits) {
02722     case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
02723     case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
02724     case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
02725     case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
02726 
02727     /* Surface slope must not be changed */
02728     default: return (((z_old != z_new) || (tileh_old != tileh_new)) ? CMD_ERROR : CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]));
02729   }
02730 
02731   /* The height of the track_corner must not be changed. The rest ensures GetRailFoundation() already. */
02732   z_old += GetSlopeZInCorner(RemoveHalftileSlope(tileh_old), track_corner);
02733   z_new += GetSlopeZInCorner(RemoveHalftileSlope(tileh_new), track_corner);
02734   if (z_old != z_new) return CMD_ERROR;
02735 
02736   CommandCost cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
02737   /* Make the ground dirty, if surface slope has changed */
02738   if (tileh_old != tileh_new) {
02739     /* If there is flat water on the lower halftile add the cost for clearing it */
02740     if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old)) cost.AddCost(_price[PR_CLEAR_WATER]);
02741     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
02742   }
02743   return  cost;
02744 }
02745 
02746 static CommandCost TerraformTile_Track(TileIndex tile, DoCommandFlag flags, uint z_new, Slope tileh_new)
02747 {
02748   uint z_old;
02749   Slope tileh_old = GetTileSlope(tile, &z_old);
02750   if (IsPlainRail(tile)) {
02751     TrackBits rail_bits = GetTrackBits(tile);
02752     /* Is there flat water on the lower halftile, that must be cleared expensively? */
02753     bool was_water = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old));
02754 
02755     _error_message = STR_ERROR_MUST_REMOVE_RAILROAD_TRACK;
02756 
02757     /* First test autoslope. However if it succeeds we still have to test the rest, because non-autoslope terraforming is cheaper. */
02758     CommandCost autoslope_result = TestAutoslopeOnRailTile(tile, flags, z_old, tileh_old, z_new, tileh_new, rail_bits);
02759 
02760     /* When there is only a single horizontal/vertical track, one corner can be terraformed. */
02761     Corner allowed_corner;
02762     switch (rail_bits) {
02763       case TRACK_BIT_RIGHT: allowed_corner = CORNER_W; break;
02764       case TRACK_BIT_UPPER: allowed_corner = CORNER_S; break;
02765       case TRACK_BIT_LEFT:  allowed_corner = CORNER_E; break;
02766       case TRACK_BIT_LOWER: allowed_corner = CORNER_N; break;
02767       default: return autoslope_result;
02768     }
02769 
02770     Foundation f_old = GetRailFoundation(tileh_old, rail_bits);
02771 
02772     /* Do not allow terraforming if allowed_corner is part of anti-zig-zag foundations */
02773     if (tileh_old != SLOPE_NS && tileh_old != SLOPE_EW && IsSpecialRailFoundation(f_old)) return autoslope_result;
02774 
02775     /* Everything is valid, which only changes allowed_corner */
02776     for (Corner corner = (Corner)0; corner < CORNER_END; corner = (Corner)(corner + 1)) {
02777       if (allowed_corner == corner) continue;
02778       if (z_old + GetSlopeZInCorner(tileh_old, corner) != z_new + GetSlopeZInCorner(tileh_new, corner)) return autoslope_result;
02779     }
02780 
02781     /* Make the ground dirty */
02782     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
02783 
02784     /* allow terraforming */
02785     return CommandCost(EXPENSES_CONSTRUCTION, was_water ? _price[PR_CLEAR_WATER] : (Money)0);
02786   } else if (_settings_game.construction.build_on_slopes && AutoslopeEnabled() &&
02787       AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRailDepotDirection(tile))) {
02788     return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
02789   }
02790   return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
02791 }
02792 
02793 
02794 extern const TileTypeProcs _tile_type_rail_procs = {
02795   DrawTile_Track,           // draw_tile_proc
02796   GetSlopeZ_Track,          // get_slope_z_proc
02797   ClearTile_Track,          // clear_tile_proc
02798   NULL,                     // add_accepted_cargo_proc
02799   GetTileDesc_Track,        // get_tile_desc_proc
02800   GetTileTrackStatus_Track, // get_tile_track_status_proc
02801   ClickTile_Track,          // click_tile_proc
02802   NULL,                     // animate_tile_proc
02803   TileLoop_Track,           // tile_loop_clear
02804   ChangeTileOwner_Track,    // change_tile_owner_clear
02805   NULL,                     // add_produced_cargo_proc
02806   VehicleEnter_Track,       // vehicle_enter_tile_proc
02807   GetFoundation_Track,      // get_foundation_proc
02808   TerraformTile_Track,      // terraform_tile_proc
02809 };

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