rail_cmd.cpp

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00001 /* $Id: rail_cmd.cpp 19665 2010-04-17 22:27:49Z 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 = Extract<RailType, 0, 4>(p1);
00373   Track track = Extract<Track, 0, 3>(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 = Extract<Track, 0, 3>(p2);
00513   CommandCost cost(EXPENSES_CONSTRUCTION);
00514   bool crossing = false;
00515 
00516   if (!ValParamTrackOrientation(track)) 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 = Extract<Track, 4, 3>(p2);
00747   bool remove = HasBit(p2, 7);
00748   RailType railtype = Extract<RailType, 0, 4>(p2);
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   RailType railtype = Extract<RailType, 0, 4>(p1);
00834   if (!ValParamRailtype(railtype)) return CMD_ERROR;
00835 
00836   Slope tileh = GetTileSlope(tile, NULL);
00837 
00838   DiagDirection dir = Extract<DiagDirection, 0, 2>(p2);
00839 
00840   /* Prohibit construction if
00841    * The tile is non-flat AND
00842    * 1) build-on-slopes is disabled
00843    * 2) the tile is steep i.e. spans two height levels
00844    * 3) the exit points in the wrong direction
00845    */
00846 
00847   if (tileh != SLOPE_FLAT && (
00848         !_settings_game.construction.build_on_slopes ||
00849         IsSteepSlope(tileh) ||
00850         !CanBuildDepotByTileh(dir, tileh)
00851       )) {
00852     return_cmd_error(STR_ERROR_FLAT_LAND_REQUIRED);
00853   }
00854 
00855   CommandCost cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00856   if (cost.Failed()) return CMD_ERROR;
00857 
00858   if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00859 
00860   if (!Depot::CanAllocateItem()) return CMD_ERROR;
00861 
00862   if (flags & DC_EXEC) {
00863     Depot *d = new Depot(tile);
00864     d->town_index = ClosestTownFromTile(tile, UINT_MAX)->index;
00865 
00866     MakeRailDepot(tile, _current_company, d->index, dir, railtype);
00867     MarkTileDirtyByTile(tile);
00868 
00869     AddSideToSignalBuffer(tile, INVALID_DIAGDIR, _current_company);
00870     YapfNotifyTrackLayoutChange(tile, DiagDirToDiagTrack(dir));
00871   }
00872 
00873   cost.AddCost(_price[PR_BUILD_DEPOT_TRAIN]);
00874   return cost;
00875 }
00876 
00897 CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00898 {
00899   Track track = Extract<Track, 0, 3>(p1);
00900   bool ctrl_pressed = HasBit(p1, 3); // was the CTRL button pressed
00901   SignalVariant sigvar = (ctrl_pressed ^ HasBit(p1, 4)) ? SIG_SEMAPHORE : SIG_ELECTRIC; // the signal variant of the new signal
00902   SignalType sigtype = Extract<SignalType, 5, 3>(p1); // the signal type of the new signal
00903   bool convert_signal = HasBit(p1, 8); // convert button pressed
00904   SignalType cycle_start = Extract<SignalType, 9, 3>(p1);
00905   SignalType cycle_stop = Extract<SignalType, 12, 3>(p1);
00906   uint num_dir_cycle = GB(p1, 15, 2);
00907 
00908   if (sigtype > SIGTYPE_LAST) return CMD_ERROR;
00909   if (cycle_start > cycle_stop || cycle_stop > SIGTYPE_LAST) return CMD_ERROR;
00910 
00911   /* You can only build signals on plain rail tiles, and the selected track must exist */
00912   if (!ValParamTrackOrientation(track) || !IsPlainRailTile(tile) ||
00913       !HasTrack(tile, track) || !EnsureNoTrainOnTrack(tile, track)) {
00914     return CMD_ERROR;
00915   }
00916 
00917   /* Protect against invalid signal copying */
00918   if (p2 != 0 && (p2 & SignalOnTrack(track)) == 0) return CMD_ERROR;
00919 
00920   if (!CheckTileOwnership(tile)) return CMD_ERROR;
00921 
00922   {
00923     /* See if this is a valid track combination for signals, (ie, no overlap) */
00924     TrackBits trackbits = GetTrackBits(tile);
00925     if (KillFirstBit(trackbits) != TRACK_BIT_NONE && // More than one track present
00926         trackbits != TRACK_BIT_HORZ &&
00927         trackbits != TRACK_BIT_VERT) {
00928       return_cmd_error(STR_ERROR_NO_SUITABLE_RAILROAD_TRACK);
00929     }
00930   }
00931 
00932   /* In case we don't want to change an existing signal, return without error. */
00933   if (HasBit(p1, 17) && HasSignalOnTrack(tile, track)) return CommandCost();
00934 
00935   /* you can not convert a signal if no signal is on track */
00936   if (convert_signal && !HasSignalOnTrack(tile, track)) return CMD_ERROR;
00937 
00938   CommandCost cost;
00939   if (!HasSignalOnTrack(tile, track)) {
00940     /* build new signals */
00941     cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS]);
00942   } else {
00943     if (p2 != 0 && sigvar != GetSignalVariant(tile, track)) {
00944       /* convert signals <-> semaphores */
00945       cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]);
00946 
00947     } else if (convert_signal) {
00948       /* convert button pressed */
00949       if (ctrl_pressed || GetSignalVariant(tile, track) != sigvar) {
00950         /* convert electric <-> semaphore */
00951         cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]);
00952       } else {
00953         /* it is free to change signal type: normal-pre-exit-combo */
00954         cost = CommandCost();
00955       }
00956 
00957     } else {
00958       /* it is free to change orientation/pre-exit-combo signals */
00959       cost = CommandCost();
00960     }
00961   }
00962 
00963   if (flags & DC_EXEC) {
00964     Train *v = NULL;
00965     /* The new/changed signal could block our path. As this can lead to
00966      * stale reservations, we clear the path reservation here and try
00967      * to redo it later on. */
00968     if (HasReservedTracks(tile, TrackToTrackBits(track))) {
00969       v = GetTrainForReservation(tile, track);
00970       if (v != NULL) FreeTrainTrackReservation(v);
00971     }
00972 
00973     if (!HasSignals(tile)) {
00974       /* there are no signals at all on this tile yet */
00975       SetHasSignals(tile, true);
00976       SetSignalStates(tile, 0xF); // all signals are on
00977       SetPresentSignals(tile, 0); // no signals built by default
00978       SetSignalType(tile, track, sigtype);
00979       SetSignalVariant(tile, track, sigvar);
00980     }
00981 
00982     if (p2 == 0) {
00983       if (!HasSignalOnTrack(tile, track)) {
00984         /* build new signals */
00985         SetPresentSignals(tile, GetPresentSignals(tile) | (IsPbsSignal(sigtype) ? KillFirstBit(SignalOnTrack(track)) : SignalOnTrack(track)));
00986         SetSignalType(tile, track, sigtype);
00987         SetSignalVariant(tile, track, sigvar);
00988         while (num_dir_cycle-- > 0) CycleSignalSide(tile, track);
00989       } else {
00990         if (convert_signal) {
00991           /* convert signal button pressed */
00992           if (ctrl_pressed) {
00993             /* toggle the pressent signal variant: SIG_ELECTRIC <-> SIG_SEMAPHORE */
00994             SetSignalVariant(tile, track, (GetSignalVariant(tile, track) == SIG_ELECTRIC) ? SIG_SEMAPHORE : SIG_ELECTRIC);
00995             /* Query current signal type so the check for PBS signals below works. */
00996             sigtype = GetSignalType(tile, track);
00997           } else {
00998             /* convert the present signal to the chosen type and variant */
00999             SetSignalType(tile, track, sigtype);
01000             SetSignalVariant(tile, track, sigvar);
01001             if (IsPbsSignal(sigtype) && (GetPresentSignals(tile) & SignalOnTrack(track)) == SignalOnTrack(track)) {
01002               SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | KillFirstBit(SignalOnTrack(track)));
01003             }
01004           }
01005 
01006         } else if (ctrl_pressed) {
01007           /* cycle between cycle_start and cycle_end */
01008           sigtype = (SignalType)(GetSignalType(tile, track) + 1);
01009 
01010           if (sigtype < cycle_start || sigtype > cycle_stop) sigtype = cycle_start;
01011 
01012           SetSignalType(tile, track, sigtype);
01013           if (IsPbsSignal(sigtype) && (GetPresentSignals(tile) & SignalOnTrack(track)) == SignalOnTrack(track)) {
01014             SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | KillFirstBit(SignalOnTrack(track)));
01015           }
01016         } else {
01017           /* cycle the signal side: both -> left -> right -> both -> ... */
01018           CycleSignalSide(tile, track);
01019           /* Query current signal type so the check for PBS signals below works. */
01020           sigtype = GetSignalType(tile, track);
01021         }
01022       }
01023     } else {
01024       /* If CmdBuildManySignals is called with copying signals, just copy the
01025        * direction of the first signal given as parameter by CmdBuildManySignals */
01026       SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | (p2 & SignalOnTrack(track)));
01027       SetSignalVariant(tile, track, sigvar);
01028       SetSignalType(tile, track, sigtype);
01029     }
01030 
01031     if (IsPbsSignal(sigtype)) {
01032       /* PBS signals should show red unless they are on a reservation. */
01033       uint mask = GetPresentSignals(tile) & SignalOnTrack(track);
01034       SetSignalStates(tile, (GetSignalStates(tile) & ~mask) | ((HasBit(GetRailReservationTrackBits(tile), track) ? UINT_MAX : 0) & mask));
01035     }
01036     MarkTileDirtyByTile(tile);
01037     AddTrackToSignalBuffer(tile, track, _current_company);
01038     YapfNotifyTrackLayoutChange(tile, track);
01039     if (v != NULL) {
01040       /* Extend the train's path if it's not stopped or loading, or not at a safe position. */
01041       if (!(((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) || v->current_order.IsType(OT_LOADING)) ||
01042           !IsSafeWaitingPosition(v, v->tile, v->GetVehicleTrackdir(), true, _settings_game.pf.forbid_90_deg)) {
01043         TryPathReserve(v, true);
01044       }
01045     }
01046   }
01047 
01048   return cost;
01049 }
01050 
01051 static bool CheckSignalAutoFill(TileIndex &tile, Trackdir &trackdir, int &signal_ctr, bool remove)
01052 {
01053   tile = AddTileIndexDiffCWrap(tile, _trackdelta[trackdir]);
01054   if (tile == INVALID_TILE) return false;
01055 
01056   /* Check for track bits on the new tile */
01057   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0));
01058 
01059   if (TracksOverlap(TrackdirBitsToTrackBits(trackdirbits))) return false;
01060   trackdirbits &= TrackdirReachesTrackdirs(trackdir);
01061 
01062   /* No track bits, must stop */
01063   if (trackdirbits == TRACKDIR_BIT_NONE) return false;
01064 
01065   /* Get the first track dir */
01066   trackdir = RemoveFirstTrackdir(&trackdirbits);
01067 
01068   /* Any left? It's a junction so we stop */
01069   if (trackdirbits != TRACKDIR_BIT_NONE) return false;
01070 
01071   switch (GetTileType(tile)) {
01072     case MP_RAILWAY:
01073       if (IsRailDepot(tile)) return false;
01074       if (!remove && HasSignalOnTrack(tile, TrackdirToTrack(trackdir))) return false;
01075       signal_ctr++;
01076       if (IsDiagonalTrackdir(trackdir)) {
01077         signal_ctr++;
01078         /* Ensure signal_ctr even so X and Y pieces get signals */
01079         ClrBit(signal_ctr, 0);
01080       }
01081       return true;
01082 
01083     case MP_ROAD:
01084       if (!IsLevelCrossing(tile)) return false;
01085       signal_ctr += 2;
01086       return true;
01087 
01088     case MP_TUNNELBRIDGE: {
01089       TileIndex orig_tile = tile; // backup old value
01090 
01091       if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return false;
01092       if (GetTunnelBridgeDirection(tile) != TrackdirToExitdir(trackdir)) return false;
01093 
01094       /* Skip to end of tunnel or bridge
01095        * note that tile is a parameter by reference, so it must be updated */
01096       tile = GetOtherTunnelBridgeEnd(tile);
01097 
01098       signal_ctr += (GetTunnelBridgeLength(orig_tile, tile) + 2) * 2;
01099       return true;
01100     }
01101 
01102     default: return false;
01103   }
01104 }
01105 
01121 static CommandCost CmdSignalTrackHelper(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01122 {
01123   CommandCost ret, total_cost(EXPENSES_CONSTRUCTION);
01124   bool err = true;
01125   TileIndex start_tile = tile;
01126 
01127   Track track = Extract<Track, 0, 3>(p2);
01128   bool mode = HasBit(p2, 3);
01129   bool semaphores = HasBit(p2, 4);
01130   bool remove = HasBit(p2, 5);
01131   bool autofill = HasBit(p2, 6);
01132   byte signal_density = GB(p2, 24, 8);
01133 
01134   if (p1 >= MapSize() || !ValParamTrackOrientation(track)) return CMD_ERROR;
01135   TileIndex end_tile = p1;
01136   if (signal_density == 0 || signal_density > 20) return CMD_ERROR;
01137 
01138   if (!IsPlainRailTile(tile)) return CMD_ERROR;
01139 
01140   /* for vertical/horizontal tracks, double the given signals density
01141    * since the original amount will be too dense (shorter tracks) */
01142   signal_density *= 2;
01143 
01144   Trackdir trackdir = TrackToTrackdir(track);
01145   if (ValidateAutoDrag(&trackdir, tile, end_tile).Failed()) return CMD_ERROR;
01146 
01147   track = TrackdirToTrack(trackdir); // trackdir might have changed, keep track in sync
01148   Trackdir start_trackdir = trackdir;
01149 
01150   /* Must start on a valid track to be able to avoid loops */
01151   if (!HasTrack(tile, track)) return CMD_ERROR;
01152 
01153   SignalType sigtype = (SignalType)GB(p2, 7, 3);
01154   if (sigtype > SIGTYPE_LAST) return CMD_ERROR;
01155 
01156   byte signals;
01157   /* copy the signal-style of the first rail-piece if existing */
01158   if (HasSignalOnTrack(tile, track)) {
01159     signals = GetPresentSignals(tile) & SignalOnTrack(track);
01160     assert(signals != 0);
01161 
01162     /* copy signal/semaphores style (independent of CTRL) */
01163     semaphores = GetSignalVariant(tile, track) != SIG_ELECTRIC;
01164 
01165     sigtype = GetSignalType(tile, track);
01166     /* Don't but copy pre-signal type */
01167     if (sigtype < SIGTYPE_PBS) sigtype = SIGTYPE_NORMAL;
01168   } else { // no signals exist, drag a two-way signal stretch
01169     signals = IsPbsSignal(sigtype) ? SignalAlongTrackdir(trackdir) : SignalOnTrack(track);
01170   }
01171 
01172   byte signal_dir = 0;
01173   if (signals & SignalAlongTrackdir(trackdir))   SetBit(signal_dir, 0);
01174   if (signals & SignalAgainstTrackdir(trackdir)) SetBit(signal_dir, 1);
01175 
01176   /* signal_ctr         - amount of tiles already processed
01177    * signals_density    - setting to put signal on every Nth tile (double space on |, -- tracks)
01178    **********
01179    * trackdir   - trackdir to build with autorail
01180    * semaphores - semaphores or signals
01181    * signals    - is there a signal/semaphore on the first tile, copy its style (two-way/single-way)
01182    *              and convert all others to semaphore/signal
01183    * remove     - 1 remove signals, 0 build signals */
01184   int signal_ctr = 0;
01185   for (;;) {
01186     /* only build/remove signals with the specified density */
01187     if ((remove && autofill) || signal_ctr % signal_density == 0) {
01188       uint32 p1 = GB(TrackdirToTrack(trackdir), 0, 3);
01189       SB(p1, 3, 1, mode);
01190       SB(p1, 4, 1, semaphores);
01191       SB(p1, 5, 3, sigtype);
01192       if (!remove && signal_ctr == 0) SetBit(p1, 17);
01193 
01194       /* Pick the correct orientation for the track direction */
01195       signals = 0;
01196       if (HasBit(signal_dir, 0)) signals |= SignalAlongTrackdir(trackdir);
01197       if (HasBit(signal_dir, 1)) signals |= SignalAgainstTrackdir(trackdir);
01198 
01199       ret = DoCommand(tile, p1, signals, flags, remove ? CMD_REMOVE_SIGNALS : CMD_BUILD_SIGNALS);
01200 
01201       /* Be user-friendly and try placing signals as much as possible */
01202       if (ret.Succeeded()) {
01203         err = false;
01204         total_cost.AddCost(ret);
01205       }
01206     }
01207 
01208     if (autofill) {
01209       if (!CheckSignalAutoFill(tile, trackdir, signal_ctr, remove)) break;
01210 
01211       /* Prevent possible loops */
01212       if (tile == start_tile && trackdir == start_trackdir) break;
01213     } else {
01214       if (tile == end_tile) break;
01215 
01216       tile += ToTileIndexDiff(_trackdelta[trackdir]);
01217       signal_ctr++;
01218 
01219       /* toggle railbit for the non-diagonal tracks (|, -- tracks) */
01220       if (IsDiagonalTrackdir(trackdir)) {
01221         signal_ctr++;
01222       } else {
01223         ToggleBit(trackdir, 0);
01224       }
01225     }
01226   }
01227 
01228   return err ? CMD_ERROR : total_cost;
01229 }
01230 
01248 CommandCost CmdBuildSignalTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01249 {
01250   return CmdSignalTrackHelper(tile, flags, p1, p2, text);
01251 }
01252 
01264 CommandCost CmdRemoveSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01265 {
01266   Track track = Extract<Track, 0, 3>(p1);
01267 
01268   if (!ValParamTrackOrientation(track) ||
01269       !IsPlainRailTile(tile) ||
01270       !HasTrack(tile, track) ||
01271       !EnsureNoTrainOnTrack(tile, track) ||
01272       !HasSignalOnTrack(tile, track)) {
01273     return CMD_ERROR;
01274   }
01275 
01276   /* Only water can remove signals from anyone */
01277   if (_current_company != OWNER_WATER && !CheckTileOwnership(tile)) return CMD_ERROR;
01278 
01279   /* Do it? */
01280   if (flags & DC_EXEC) {
01281     Train *v = NULL;
01282     if (HasReservedTracks(tile, TrackToTrackBits(track))) {
01283       v = GetTrainForReservation(tile, track);
01284     } else if (IsPbsSignal(GetSignalType(tile, track))) {
01285       /* PBS signal, might be the end of a path reservation. */
01286       Trackdir td = TrackToTrackdir(track);
01287       for (int i = 0; v == NULL && i < 2; i++, td = ReverseTrackdir(td)) {
01288         /* Only test the active signal side. */
01289         if (!HasSignalOnTrackdir(tile, ReverseTrackdir(td))) continue;
01290         TileIndex next = TileAddByDiagDir(tile, TrackdirToExitdir(td));
01291         TrackBits tracks = TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(td));
01292         if (HasReservedTracks(next, tracks)) {
01293           v = GetTrainForReservation(next, TrackBitsToTrack(GetReservedTrackbits(next) & tracks));
01294         }
01295       }
01296     }
01297     SetPresentSignals(tile, GetPresentSignals(tile) & ~SignalOnTrack(track));
01298 
01299     /* removed last signal from tile? */
01300     if (GetPresentSignals(tile) == 0) {
01301       SetSignalStates(tile, 0);
01302       SetHasSignals(tile, false);
01303       SetSignalVariant(tile, INVALID_TRACK, SIG_ELECTRIC); // remove any possible semaphores
01304     }
01305 
01306     AddTrackToSignalBuffer(tile, track, GetTileOwner(tile));
01307     YapfNotifyTrackLayoutChange(tile, track);
01308     if (v != NULL) TryPathReserve(v, false);
01309 
01310     MarkTileDirtyByTile(tile);
01311   }
01312 
01313   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_SIGNALS]);
01314 }
01315 
01333 CommandCost CmdRemoveSignalTrack(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01334 {
01335   return CmdSignalTrackHelper(tile, flags, p1, SetBit(p2, 5), text); // bit 5 is remove bit
01336 }
01337 
01339 static Vehicle *UpdateTrainPowerProc(Vehicle *v, void *data)
01340 {
01341   if (v->type != VEH_TRAIN) return NULL;
01342 
01343   /* Similar checks as in Train::PowerChanged() */
01344 
01345   Train *t = Train::From(v);
01346   if (t->IsArticulatedPart()) return NULL;
01347 
01348   const RailVehicleInfo *rvi = RailVehInfo(t->engine_type);
01349   if (GetVehicleProperty(t, PROP_TRAIN_POWER, rvi->power) != 0) t->First()->PowerChanged();
01350 
01351   return NULL;
01352 }
01353 
01363 CommandCost CmdConvertRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01364 {
01365   CommandCost cost(EXPENSES_CONSTRUCTION);
01366   RailType totype = Extract<RailType, 0, 4>(p2);
01367 
01368   if (!ValParamRailtype(totype)) return CMD_ERROR;
01369   if (p1 >= MapSize()) return CMD_ERROR;
01370 
01371   uint ex = TileX(tile);
01372   uint ey = TileY(tile);
01373   uint sx = TileX(p1);
01374   uint sy = TileY(p1);
01375 
01376   /* make sure sx,sy are smaller than ex,ey */
01377   if (ex < sx) Swap(ex, sx);
01378   if (ey < sy) Swap(ey, sy);
01379 
01380   _error_message = STR_ERROR_NO_SUITABLE_RAILROAD_TRACK; // by default, there is no track to convert
01381 
01382   for (uint x = sx; x <= ex; ++x) {
01383     for (uint y = sy; y <= ey; ++y) {
01384       TileIndex tile = TileXY(x, y);
01385       TileType tt = GetTileType(tile);
01386 
01387       /* Check if there is any track on tile */
01388       switch (tt) {
01389         case MP_RAILWAY:
01390           break;
01391         case MP_STATION:
01392           if (!HasStationRail(tile)) continue;
01393           break;
01394         case MP_ROAD:
01395           if (!IsLevelCrossing(tile)) continue;
01396           break;
01397         case MP_TUNNELBRIDGE:
01398           if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) continue;
01399           break;
01400         default: continue;
01401       }
01402 
01403       /* Original railtype we are converting from */
01404       RailType type = GetRailType(tile);
01405 
01406       /* Converting to the same type or converting 'hidden' elrail -> rail */
01407       if (type == totype || (_settings_game.vehicle.disable_elrails && totype == RAILTYPE_RAIL && type == RAILTYPE_ELECTRIC)) continue;
01408 
01409       /* Trying to convert other's rail */
01410       if (!CheckTileOwnership(tile)) continue;
01411 
01412       SmallVector<Train *, 2> vehicles_affected;
01413 
01414       /* Vehicle on the tile when not converting Rail <-> ElRail
01415        * Tunnels and bridges have special check later */
01416       if (tt != MP_TUNNELBRIDGE) {
01417         if (!IsCompatibleRail(type, totype) && !EnsureNoVehicleOnGround(tile)) continue;
01418         if (flags & DC_EXEC) { // we can safely convert, too
01419           TrackBits reserved = GetReservedTrackbits(tile);
01420           Track     track;
01421           while ((track = RemoveFirstTrack(&reserved)) != INVALID_TRACK) {
01422             Train *v = GetTrainForReservation(tile, track);
01423             if (v != NULL && !HasPowerOnRail(v->railtype, totype)) {
01424               /* No power on new rail type, reroute. */
01425               FreeTrainTrackReservation(v);
01426               *vehicles_affected.Append() = v;
01427             }
01428           }
01429 
01430           SetRailType(tile, totype);
01431           MarkTileDirtyByTile(tile);
01432           /* update power of train engines on this tile */
01433           FindVehicleOnPos(tile, NULL, &UpdateTrainPowerProc);
01434         }
01435       }
01436 
01437       switch (tt) {
01438         case MP_RAILWAY:
01439           switch (GetRailTileType(tile)) {
01440             case RAIL_TILE_DEPOT:
01441               if (flags & DC_EXEC) {
01442                 /* notify YAPF about the track layout change */
01443                 YapfNotifyTrackLayoutChange(tile, GetRailDepotTrack(tile));
01444 
01445                 /* Update build vehicle window related to this depot */
01446                 InvalidateWindowData(WC_VEHICLE_DEPOT, tile);
01447                 InvalidateWindowData(WC_BUILD_VEHICLE, tile);
01448               }
01449               cost.AddCost(RailConvertCost(type, totype));
01450               break;
01451 
01452             default: // RAIL_TILE_NORMAL, RAIL_TILE_SIGNALS
01453               if (flags & DC_EXEC) {
01454                 /* notify YAPF about the track layout change */
01455                 TrackBits tracks = GetTrackBits(tile);
01456                 while (tracks != TRACK_BIT_NONE) {
01457                   YapfNotifyTrackLayoutChange(tile, RemoveFirstTrack(&tracks));
01458                 }
01459               }
01460               cost.AddCost(RailConvertCost(type, totype) * CountBits(GetTrackBits(tile)));
01461               break;
01462           }
01463           break;
01464 
01465         case MP_TUNNELBRIDGE: {
01466           TileIndex endtile = GetOtherTunnelBridgeEnd(tile);
01467 
01468           /* If both ends of tunnel/bridge are in the range, do not try to convert twice -
01469            * it would cause assert because of different test and exec runs */
01470           if (endtile < tile && TileX(endtile) >= sx && TileX(endtile) <= ex &&
01471               TileY(endtile) >= sy && TileY(endtile) <= ey) continue;
01472 
01473           /* When not coverting rail <-> el. rail, any vehicle cannot be in tunnel/bridge */
01474           if (!IsCompatibleRail(GetRailType(tile), totype) &&
01475               HasVehicleOnTunnelBridge(tile, endtile)) continue;
01476 
01477           if (flags & DC_EXEC) {
01478             Track track = DiagDirToDiagTrack(GetTunnelBridgeDirection(tile));
01479             if (HasTunnelBridgeReservation(tile)) {
01480               Train *v = GetTrainForReservation(tile, track);
01481               if (v != NULL && !HasPowerOnRail(v->railtype, totype)) {
01482                 /* No power on new rail type, reroute. */
01483                 FreeTrainTrackReservation(v);
01484                 *vehicles_affected.Append() = v;
01485               }
01486             }
01487             SetRailType(tile, totype);
01488             SetRailType(endtile, totype);
01489 
01490             FindVehicleOnPos(tile, NULL, &UpdateTrainPowerProc);
01491             FindVehicleOnPos(endtile, NULL, &UpdateTrainPowerProc);
01492 
01493             YapfNotifyTrackLayoutChange(tile, track);
01494             YapfNotifyTrackLayoutChange(endtile, track);
01495 
01496             MarkTileDirtyByTile(tile);
01497             MarkTileDirtyByTile(endtile);
01498 
01499             if (IsBridge(tile)) {
01500               TileIndexDiff delta = TileOffsByDiagDir(GetTunnelBridgeDirection(tile));
01501               TileIndex t = tile + delta;
01502               for (; t != endtile; t += delta) MarkTileDirtyByTile(t); // TODO encapsulate this into a function
01503             }
01504           }
01505 
01506           cost.AddCost((GetTunnelBridgeLength(tile, endtile) + 2) * RailConvertCost(type, totype));
01507         } break;
01508 
01509         default: // MP_STATION, MP_ROAD
01510           if (flags & DC_EXEC) {
01511             Track track = ((tt == MP_STATION) ? GetRailStationTrack(tile) : GetCrossingRailTrack(tile));
01512             YapfNotifyTrackLayoutChange(tile, track);
01513           }
01514 
01515           cost.AddCost(RailConvertCost(type, totype));
01516           break;
01517       }
01518 
01519       for (uint i = 0; i < vehicles_affected.Length(); ++i) {
01520         TryPathReserve(vehicles_affected[i], true);
01521       }
01522     }
01523   }
01524 
01525   return (cost.GetCost() == 0) ? CMD_ERROR : cost;
01526 }
01527 
01528 static CommandCost RemoveTrainDepot(TileIndex tile, DoCommandFlag flags)
01529 {
01530   if (!CheckTileOwnership(tile) && _current_company != OWNER_WATER)
01531     return CMD_ERROR;
01532 
01533   if (!EnsureNoVehicleOnGround(tile))
01534     return CMD_ERROR;
01535 
01536   if (flags & DC_EXEC) {
01537     /* read variables before the depot is removed */
01538     DiagDirection dir = GetRailDepotDirection(tile);
01539     Owner owner = GetTileOwner(tile);
01540     Train *v = NULL;
01541 
01542     if (HasDepotReservation(tile)) {
01543       v = GetTrainForReservation(tile, DiagDirToDiagTrack(dir));
01544       if (v != NULL) FreeTrainTrackReservation(v);
01545     }
01546 
01547     delete Depot::GetByTile(tile);
01548     DoClearSquare(tile);
01549     AddSideToSignalBuffer(tile, dir, owner);
01550     YapfNotifyTrackLayoutChange(tile, DiagDirToDiagTrack(dir));
01551     if (v != NULL) TryPathReserve(v, true);
01552   }
01553 
01554   return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_DEPOT_TRAIN]);
01555 }
01556 
01557 static CommandCost ClearTile_Track(TileIndex tile, DoCommandFlag flags)
01558 {
01559   CommandCost cost(EXPENSES_CONSTRUCTION);
01560 
01561   if (flags & DC_AUTO) {
01562     if (!IsTileOwner(tile, _current_company)) {
01563       return_cmd_error(STR_ERROR_AREA_IS_OWNED_BY_ANOTHER);
01564     }
01565 
01566     if (IsPlainRail(tile)) {
01567       return_cmd_error(STR_ERROR_MUST_REMOVE_RAILROAD_TRACK);
01568     } else {
01569       return_cmd_error(STR_ERROR_BUILDING_MUST_BE_DEMOLISHED);
01570     }
01571   }
01572 
01573   switch (GetRailTileType(tile)) {
01574     case RAIL_TILE_SIGNALS:
01575     case RAIL_TILE_NORMAL: {
01576       Slope tileh = GetTileSlope(tile, NULL);
01577       /* Is there flat water on the lower halftile, that gets cleared expensively? */
01578       bool water_ground = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh));
01579 
01580       TrackBits tracks = GetTrackBits(tile);
01581       while (tracks != TRACK_BIT_NONE) {
01582         Track track = RemoveFirstTrack(&tracks);
01583         CommandCost ret = DoCommand(tile, 0, track, flags, CMD_REMOVE_SINGLE_RAIL);
01584         if (ret.Failed()) return CMD_ERROR;
01585         cost.AddCost(ret);
01586       }
01587 
01588       /* when bankrupting, don't make water dirty, there could be a ship on lower halftile */
01589       if (water_ground && !(flags & DC_BANKRUPT)) {
01590         if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
01591 
01592         /* The track was removed, and left a coast tile. Now also clear the water. */
01593         if (flags & DC_EXEC) DoClearSquare(tile);
01594         cost.AddCost(_price[PR_CLEAR_WATER]);
01595       }
01596 
01597       return cost;
01598     }
01599 
01600     case RAIL_TILE_DEPOT:
01601       return RemoveTrainDepot(tile, flags);
01602 
01603     default:
01604       return CMD_ERROR;
01605   }
01606 }
01607 
01612 static uint GetSaveSlopeZ(uint x, uint y, Track track)
01613 {
01614   switch (track) {
01615     case TRACK_UPPER: x &= ~0xF; y &= ~0xF; break;
01616     case TRACK_LOWER: x |=  0xF; y |=  0xF; break;
01617     case TRACK_LEFT:  x |=  0xF; y &= ~0xF; break;
01618     case TRACK_RIGHT: x &= ~0xF; y |=  0xF; break;
01619     default: break;
01620   }
01621   return GetSlopeZ(x, y);
01622 }
01623 
01624 static void DrawSingleSignal(TileIndex tile, Track track, byte condition, uint image, uint pos)
01625 {
01626   bool side = (_settings_game.vehicle.road_side != 0) && _settings_game.construction.signal_side;
01627   static const Point SignalPositions[2][12] = {
01628     { // Signals on the left side
01629     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01630       { 8,  5}, {14,  1}, { 1, 14}, { 9, 11}, { 1,  0}, { 3, 10},
01631     /*  LOWER     LOWER     X         X         Y         Y     */
01632       {11,  4}, {14, 14}, {11,  3}, { 4, 13}, { 3,  4}, {11, 13}
01633     }, { // Signals on the right side
01634     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01635       {14,  1}, {12, 10}, { 4,  6}, { 1, 14}, {10,  4}, { 0,  1},
01636     /*  LOWER     LOWER     X         X         Y         Y     */
01637       {14, 14}, { 5, 12}, {11, 13}, { 4,  3}, {13,  4}, { 3, 11}
01638     }
01639   };
01640 
01641   uint x = TileX(tile) * TILE_SIZE + SignalPositions[side][pos].x;
01642   uint y = TileY(tile) * TILE_SIZE + SignalPositions[side][pos].y;
01643 
01644   SpriteID sprite;
01645 
01646   SignalType type       = GetSignalType(tile, track);
01647   SignalVariant variant = GetSignalVariant(tile, track);
01648 
01649   if (type == SIGTYPE_NORMAL && variant == SIG_ELECTRIC) {
01650     /* Normal electric signals are picked from original sprites. */
01651     sprite = SPR_ORIGINAL_SIGNALS_BASE + image + condition;
01652   } else {
01653     /* All other signals are picked from add on sprites. */
01654     sprite = SPR_SIGNALS_BASE + (type - 1) * 16 + variant * 64 + image + condition + (type > SIGTYPE_LAST_NOPBS ? 64 : 0);
01655   }
01656 
01657   AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
01658 }
01659 
01660 static uint32 _drawtile_track_palette;
01661 
01662 
01663 static void DrawTrackFence_NW(const TileInfo *ti, SpriteID base_image)
01664 {
01665   RailFenceOffset rfo = RFO_FLAT_X;
01666   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SW : RFO_SLOPE_NE;
01667   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01668     ti->x, ti->y + 1, 16, 1, 4, ti->z);
01669 }
01670 
01671 static void DrawTrackFence_SE(const TileInfo *ti, SpriteID base_image)
01672 {
01673   RailFenceOffset rfo = RFO_FLAT_X;
01674   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SW : RFO_SLOPE_NE;
01675   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01676     ti->x, ti->y + TILE_SIZE - 1, 16, 1, 4, ti->z);
01677 }
01678 
01679 static void DrawTrackFence_NW_SE(const TileInfo *ti, SpriteID base_image)
01680 {
01681   DrawTrackFence_NW(ti, base_image);
01682   DrawTrackFence_SE(ti, base_image);
01683 }
01684 
01685 static void DrawTrackFence_NE(const TileInfo *ti, SpriteID base_image)
01686 {
01687   RailFenceOffset rfo = RFO_FLAT_Y;
01688   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SE : RFO_SLOPE_NW;
01689   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01690     ti->x + 1, ti->y, 1, 16, 4, ti->z);
01691 }
01692 
01693 static void DrawTrackFence_SW(const TileInfo *ti, SpriteID base_image)
01694 {
01695   RailFenceOffset rfo = RFO_FLAT_Y;
01696   if (ti->tileh != SLOPE_FLAT) rfo = (ti->tileh & SLOPE_S) ? RFO_SLOPE_SE : RFO_SLOPE_NW;
01697   AddSortableSpriteToDraw(base_image + rfo, _drawtile_track_palette,
01698     ti->x + TILE_SIZE - 1, ti->y, 1, 16, 4, ti->z);
01699 }
01700 
01701 static void DrawTrackFence_NE_SW(const TileInfo *ti, SpriteID base_image)
01702 {
01703   DrawTrackFence_NE(ti, base_image);
01704   DrawTrackFence_SW(ti, base_image);
01705 }
01706 
01710 static void DrawTrackFence_NS_1(const TileInfo *ti, SpriteID base_image)
01711 {
01712   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_W);
01713   AddSortableSpriteToDraw(base_image + RFO_FLAT_VERT, _drawtile_track_palette,
01714     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01715 }
01716 
01720 static void DrawTrackFence_NS_2(const TileInfo *ti, SpriteID base_image)
01721 {
01722   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_E);
01723   AddSortableSpriteToDraw(base_image + RFO_FLAT_VERT, _drawtile_track_palette,
01724     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01725 }
01726 
01730 static void DrawTrackFence_WE_1(const TileInfo *ti, SpriteID base_image)
01731 {
01732   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_N);
01733   AddSortableSpriteToDraw(base_image + RFO_FLAT_HORZ, _drawtile_track_palette,
01734     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01735 }
01736 
01740 static void DrawTrackFence_WE_2(const TileInfo *ti, SpriteID base_image)
01741 {
01742   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_S);
01743   AddSortableSpriteToDraw(base_image + RFO_FLAT_HORZ, _drawtile_track_palette,
01744     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01745 }
01746 
01747 
01748 static void DrawTrackDetails(const TileInfo *ti, const RailtypeInfo *rti)
01749 {
01750   /* Base sprite for track fences. */
01751   SpriteID base_image = GetCustomRailSprite(rti, ti->tile, RTSG_FENCES);
01752   if (base_image == 0) base_image = SPR_TRACK_FENCE_FLAT_X;
01753 
01754   switch (GetRailGroundType(ti->tile)) {
01755     case RAIL_GROUND_FENCE_NW:     DrawTrackFence_NW(ti, base_image);    break;
01756     case RAIL_GROUND_FENCE_SE:     DrawTrackFence_SE(ti, base_image);    break;
01757     case RAIL_GROUND_FENCE_SENW:   DrawTrackFence_NW_SE(ti, base_image); break;
01758     case RAIL_GROUND_FENCE_NE:     DrawTrackFence_NE(ti, base_image);    break;
01759     case RAIL_GROUND_FENCE_SW:     DrawTrackFence_SW(ti, base_image);    break;
01760     case RAIL_GROUND_FENCE_NESW:   DrawTrackFence_NE_SW(ti, base_image); break;
01761     case RAIL_GROUND_FENCE_VERT1:  DrawTrackFence_NS_1(ti, base_image);  break;
01762     case RAIL_GROUND_FENCE_VERT2:  DrawTrackFence_NS_2(ti, base_image);  break;
01763     case RAIL_GROUND_FENCE_HORIZ1: DrawTrackFence_WE_1(ti, base_image);  break;
01764     case RAIL_GROUND_FENCE_HORIZ2: DrawTrackFence_WE_2(ti, base_image);  break;
01765     case RAIL_GROUND_WATER: {
01766       Corner track_corner;
01767       if (IsHalftileSlope(ti->tileh)) {
01768         /* Steep slope or one-corner-raised slope with halftile foundation */
01769         track_corner = GetHalftileSlopeCorner(ti->tileh);
01770       } else {
01771         /* Three-corner-raised slope */
01772         track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
01773       }
01774       switch (track_corner) {
01775         case CORNER_W: DrawTrackFence_NS_1(ti, base_image); break;
01776         case CORNER_S: DrawTrackFence_WE_2(ti, base_image); break;
01777         case CORNER_E: DrawTrackFence_NS_2(ti, base_image); break;
01778         case CORNER_N: DrawTrackFence_WE_1(ti, base_image); break;
01779         default: NOT_REACHED();
01780       }
01781       break;
01782     }
01783     default: break;
01784   }
01785 }
01786 
01787 /* SubSprite for drawing the track halftile of 'three-corners-raised'-sloped rail sprites. */
01788 static const int INF = 1000; // big number compared to tilesprite size
01789 static const SubSprite _halftile_sub_sprite[4] = {
01790   { -INF    , -INF  , 32 - 33, INF     }, // CORNER_W, clip 33 pixels from right
01791   { -INF    ,  0 + 7, INF    , INF     }, // CORNER_S, clip 7 pixels from top
01792   { -31 + 33, -INF  , INF    , INF     }, // CORNER_E, clip 33 pixels from left
01793   { -INF    , -INF  , INF    , 30 - 23 }  // CORNER_N, clip 23 pixels from bottom
01794 };
01795 
01796 static inline void DrawTrackSprite(SpriteID sprite, PaletteID pal, const TileInfo *ti, Slope s)
01797 {
01798   DrawGroundSprite(sprite, pal, NULL, 0, (ti->tileh & s) ? -8 : 0);
01799 }
01800 
01801 static void DrawTrackBitsOverlay(TileInfo *ti, TrackBits track, const RailtypeInfo *rti)
01802 {
01803   RailGroundType rgt = GetRailGroundType(ti->tile);
01804   Foundation f = GetRailFoundation(ti->tileh, track);
01805   Corner halftile_corner = CORNER_INVALID;
01806 
01807   if (IsNonContinuousFoundation(f)) {
01808     /* Save halftile corner */
01809     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
01810     /* Draw lower part first */
01811     track &= ~CornerToTrackBits(halftile_corner);
01812     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
01813   }
01814 
01815   DrawFoundation(ti, f);
01816   /* DrawFoundation modifies ti */
01817 
01818   /* Draw ground */
01819   if (track == TRACK_BIT_NONE && rgt == RAIL_GROUND_WATER) {
01820     if (IsSteepSlope(ti->tileh)) {
01821       DrawShoreTile(ti->tileh);
01822     } else {
01823       DrawGroundSprite(SPR_FLAT_WATER_TILE, PAL_NONE);
01824     }
01825   } else {
01826     SpriteID image;
01827 
01828     switch (rgt) {
01829       case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
01830       case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOW_DESERT_TILE; break;
01831       default:                     image = SPR_FLAT_GRASS_TILE; break;
01832     }
01833 
01834     image += _tileh_to_sprite[ti->tileh];
01835 
01836     DrawGroundSprite(image, PAL_NONE);
01837   }
01838 
01839   SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
01840   SpriteID ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND);
01841   TrackBits pbs = _settings_client.gui.show_track_reservation ? GetRailReservationTrackBits(ti->tile) : TRACK_BIT_NONE;
01842 
01843   if (track == TRACK_BIT_NONE) {
01844     /* Half-tile foundation, no track here? */
01845   } else if (ti->tileh == SLOPE_NW && track == TRACK_BIT_Y) {
01846     DrawGroundSprite(ground + RTO_SLOPE_NW, PAL_NONE);
01847     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 9, PALETTE_CRASH);
01848   } else if (ti->tileh == SLOPE_NE && track == TRACK_BIT_X) {
01849     DrawGroundSprite(ground + RTO_SLOPE_NE, PAL_NONE);
01850     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 6, PALETTE_CRASH);
01851   } else if (ti->tileh == SLOPE_SE && track == TRACK_BIT_Y) {
01852     DrawGroundSprite(ground + RTO_SLOPE_SE, PAL_NONE);
01853     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 7, PALETTE_CRASH);
01854   } else if (ti->tileh == SLOPE_SW && track == TRACK_BIT_X) {
01855     DrawGroundSprite(ground + RTO_SLOPE_SW, PAL_NONE);
01856     if (pbs != TRACK_BIT_NONE) DrawGroundSprite(overlay + 8, PALETTE_CRASH);
01857   } else {
01858     switch (track) {
01859       /* Draw single ground sprite when not overlapping. No track overlay
01860        * is necessary for these sprites. */
01861       case TRACK_BIT_X:     DrawGroundSprite(ground + RTO_X, PAL_NONE); break;
01862       case TRACK_BIT_Y:     DrawGroundSprite(ground + RTO_Y, PAL_NONE); break;
01863       case TRACK_BIT_UPPER: DrawTrackSprite(ground + RTO_N, PAL_NONE, ti, SLOPE_N); break;
01864       case TRACK_BIT_LOWER: DrawTrackSprite(ground + RTO_S, PAL_NONE, ti, SLOPE_S); break;
01865       case TRACK_BIT_RIGHT: DrawTrackSprite(ground + RTO_E, PAL_NONE, ti, SLOPE_E); break;
01866       case TRACK_BIT_LEFT:  DrawTrackSprite(ground + RTO_W, PAL_NONE, ti, SLOPE_W); break;
01867       case TRACK_BIT_CROSS: DrawGroundSprite(ground + RTO_CROSSING_XY, PAL_NONE); break;
01868       case TRACK_BIT_HORZ:  DrawTrackSprite(ground + RTO_N, PAL_NONE, ti, SLOPE_N);
01869                             DrawTrackSprite(ground + RTO_S, PAL_NONE, ti, SLOPE_S); break;
01870       case TRACK_BIT_VERT:  DrawTrackSprite(ground + RTO_E, PAL_NONE, ti, SLOPE_E);
01871                             DrawTrackSprite(ground + RTO_W, PAL_NONE, ti, SLOPE_W); break;
01872 
01873       default:
01874         /* We're drawing a junction tile */
01875         if ((track & TRACK_BIT_3WAY_NE) == 0) {
01876           DrawGroundSprite(ground + RTO_JUNCTION_SW, PAL_NONE);
01877         } else if ((track & TRACK_BIT_3WAY_SW) == 0) {
01878           DrawGroundSprite(ground + RTO_JUNCTION_NE, PAL_NONE);
01879         } else if ((track & TRACK_BIT_3WAY_NW) == 0) {
01880           DrawGroundSprite(ground + RTO_JUNCTION_SE, PAL_NONE);
01881         } else if ((track & TRACK_BIT_3WAY_SE) == 0) {
01882           DrawGroundSprite(ground + RTO_JUNCTION_NW, PAL_NONE);
01883         } else {
01884           DrawGroundSprite(ground + RTO_JUNCTION_NSEW, PAL_NONE);
01885         }
01886 
01887         /* Mask out PBS bits as we shall draw them afterwards anyway. */
01888         track &= ~pbs;
01889 
01890         /* Draw regular track bits */
01891         if (track & TRACK_BIT_X)     DrawGroundSprite(overlay + RTO_X, PAL_NONE);
01892         if (track & TRACK_BIT_Y)     DrawGroundSprite(overlay + RTO_Y, PAL_NONE);
01893         if (track & TRACK_BIT_UPPER) DrawGroundSprite(overlay + RTO_N, PAL_NONE);
01894         if (track & TRACK_BIT_LOWER) DrawGroundSprite(overlay + RTO_S, PAL_NONE);
01895         if (track & TRACK_BIT_RIGHT) DrawGroundSprite(overlay + RTO_E, PAL_NONE);
01896         if (track & TRACK_BIT_LEFT)  DrawGroundSprite(overlay + RTO_W, PAL_NONE);
01897     }
01898 
01899     /* Draw reserved track bits */
01900     if (pbs & TRACK_BIT_X)     DrawGroundSprite(overlay + RTO_X, PALETTE_CRASH);
01901     if (pbs & TRACK_BIT_Y)     DrawGroundSprite(overlay + RTO_Y, PALETTE_CRASH);
01902     if (pbs & TRACK_BIT_UPPER) DrawTrackSprite(overlay + RTO_N, PALETTE_CRASH, ti, SLOPE_N);
01903     if (pbs & TRACK_BIT_LOWER) DrawTrackSprite(overlay + RTO_S, PALETTE_CRASH, ti, SLOPE_S);
01904     if (pbs & TRACK_BIT_RIGHT) DrawTrackSprite(overlay + RTO_E, PALETTE_CRASH, ti, SLOPE_E);
01905     if (pbs & TRACK_BIT_LEFT)  DrawTrackSprite(overlay + RTO_W, PALETTE_CRASH, ti, SLOPE_W);
01906   }
01907 
01908   if (IsValidCorner(halftile_corner)) {
01909     DrawFoundation(ti, HalftileFoundation(halftile_corner));
01910 
01911     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
01912     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
01913 
01914     SpriteID image;
01915     switch (rgt) {
01916       case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
01917       case RAIL_GROUND_ICE_DESERT:
01918       case RAIL_GROUND_HALF_SNOW:  image = SPR_FLAT_SNOW_DESERT_TILE; break;
01919       default:                     image = SPR_FLAT_GRASS_TILE; break;
01920     }
01921 
01922     image += _tileh_to_sprite[fake_slope];
01923 
01924     DrawGroundSprite(image, PAL_NONE, &(_halftile_sub_sprite[halftile_corner]));
01925 
01926     track = CornerToTrackBits(halftile_corner);
01927 
01928     int offset;
01929     switch (track) {
01930       default: NOT_REACHED();
01931       case TRACK_BIT_UPPER: offset = RTO_N; break;
01932       case TRACK_BIT_LOWER: offset = RTO_S; break;
01933       case TRACK_BIT_RIGHT: offset = RTO_E; break;
01934       case TRACK_BIT_LEFT:  offset = RTO_W; break;
01935     }
01936 
01937     DrawTrackSprite(ground + offset, PAL_NONE, ti, fake_slope);
01938     if (HasReservedTracks(ti->tile, track)) {
01939       DrawTrackSprite(overlay + offset, PALETTE_CRASH, ti, fake_slope);
01940     }
01941   }
01942 }
01943 
01949 static void DrawTrackBits(TileInfo *ti, TrackBits track)
01950 {
01951   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
01952 
01953   if (rti->UsesOverlay()) {
01954     DrawTrackBitsOverlay(ti, track, rti);
01955     return;
01956   }
01957 
01958   RailGroundType rgt = GetRailGroundType(ti->tile);
01959   Foundation f = GetRailFoundation(ti->tileh, track);
01960   Corner halftile_corner = CORNER_INVALID;
01961 
01962   if (IsNonContinuousFoundation(f)) {
01963     /* Save halftile corner */
01964     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
01965     /* Draw lower part first */
01966     track &= ~CornerToTrackBits(halftile_corner);
01967     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
01968   }
01969 
01970   DrawFoundation(ti, f);
01971   /* DrawFoundation modifies ti */
01972 
01973   SpriteID image;
01974   PaletteID pal = PAL_NONE;
01975   const SubSprite *sub = NULL;
01976   bool junction = false;
01977 
01978   /* Select the sprite to use. */
01979   if (track == 0) {
01980     /* Clear ground (only track on halftile foundation) */
01981     if (rgt == RAIL_GROUND_WATER) {
01982       if (IsSteepSlope(ti->tileh)) {
01983         DrawShoreTile(ti->tileh);
01984         image = 0;
01985       } else {
01986         image = SPR_FLAT_WATER_TILE;
01987       }
01988     } else {
01989       switch (rgt) {
01990         case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
01991         case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOW_DESERT_TILE; break;
01992         default:                     image = SPR_FLAT_GRASS_TILE; break;
01993       }
01994       image += _tileh_to_sprite[ti->tileh];
01995     }
01996   } else {
01997     if (ti->tileh != SLOPE_FLAT) {
01998       /* track on non-flat ground */
01999       image = _track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.track_y;
02000     } else {
02001       /* track on flat ground */
02002       (image = rti->base_sprites.track_y, track == TRACK_BIT_Y) ||
02003       (image++,                           track == TRACK_BIT_X) ||
02004       (image++,                           track == TRACK_BIT_UPPER) ||
02005       (image++,                           track == TRACK_BIT_LOWER) ||
02006       (image++,                           track == TRACK_BIT_RIGHT) ||
02007       (image++,                           track == TRACK_BIT_LEFT) ||
02008       (image++,                           track == TRACK_BIT_CROSS) ||
02009 
02010       (image = rti->base_sprites.track_ns, track == TRACK_BIT_HORZ) ||
02011       (image++,                            track == TRACK_BIT_VERT) ||
02012 
02013       (junction = true, false) ||
02014       (image = rti->base_sprites.ground, (track & TRACK_BIT_3WAY_NE) == 0) ||
02015       (image++,                          (track & TRACK_BIT_3WAY_SW) == 0) ||
02016       (image++,                          (track & TRACK_BIT_3WAY_NW) == 0) ||
02017       (image++,                          (track & TRACK_BIT_3WAY_SE) == 0) ||
02018       (image++, true);
02019     }
02020 
02021     switch (rgt) {
02022       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
02023       case RAIL_GROUND_ICE_DESERT: image += rti->snow_offset;  break;
02024       case RAIL_GROUND_WATER: {
02025         /* three-corner-raised slope */
02026         DrawShoreTile(ti->tileh);
02027         Corner track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
02028         sub = &(_halftile_sub_sprite[track_corner]);
02029         break;
02030       }
02031       default: break;
02032     }
02033   }
02034 
02035   if (image != 0) DrawGroundSprite(image, pal, sub);
02036 
02037   /* Draw track pieces individually for junction tiles */
02038   if (junction) {
02039     if (track & TRACK_BIT_X)     DrawGroundSprite(rti->base_sprites.single_x, PAL_NONE);
02040     if (track & TRACK_BIT_Y)     DrawGroundSprite(rti->base_sprites.single_y, PAL_NONE);
02041     if (track & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PAL_NONE);
02042     if (track & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PAL_NONE);
02043     if (track & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PAL_NONE);
02044     if (track & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PAL_NONE);
02045   }
02046 
02047   /* PBS debugging, draw reserved tracks darker */
02048   if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation) {
02049     /* Get reservation, but mask track on halftile slope */
02050     TrackBits pbs = GetRailReservationTrackBits(ti->tile) & track;
02051     if (pbs & TRACK_BIT_X) {
02052       if (ti->tileh == SLOPE_FLAT || ti->tileh == SLOPE_ELEVATED) {
02053         DrawGroundSprite(rti->base_sprites.single_x, PALETTE_CRASH);
02054       } else {
02055         DrawGroundSprite(_track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.single_sloped - 20, PALETTE_CRASH);
02056       }
02057     }
02058     if (pbs & TRACK_BIT_Y) {
02059       if (ti->tileh == SLOPE_FLAT || ti->tileh == SLOPE_ELEVATED) {
02060         DrawGroundSprite(rti->base_sprites.single_y, PALETTE_CRASH);
02061       } else {
02062         DrawGroundSprite(_track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.single_sloped - 20, PALETTE_CRASH);
02063       }
02064     }
02065     if (pbs & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_N ? -TILE_HEIGHT : 0);
02066     if (pbs & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_S ? -TILE_HEIGHT : 0);
02067     if (pbs & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_W ? -TILE_HEIGHT : 0);
02068     if (pbs & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PALETTE_CRASH, NULL, 0, ti->tileh & SLOPE_E ? -TILE_HEIGHT : 0);
02069   }
02070 
02071   if (IsValidCorner(halftile_corner)) {
02072     DrawFoundation(ti, HalftileFoundation(halftile_corner));
02073 
02074     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
02075     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
02076     image = _track_sloped_sprites[fake_slope - 1] + rti->base_sprites.track_y;
02077     pal = PAL_NONE;
02078     switch (rgt) {
02079       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
02080       case RAIL_GROUND_ICE_DESERT:
02081       case RAIL_GROUND_HALF_SNOW:  image += rti->snow_offset;  break; // higher part has snow in this case too
02082       default: break;
02083     }
02084     DrawGroundSprite(image, pal, &(_halftile_sub_sprite[halftile_corner]));
02085 
02086     if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasReservedTracks(ti->tile, CornerToTrackBits(halftile_corner))) {
02087       static const byte _corner_to_track_sprite[] = {3, 1, 2, 0};
02088       DrawGroundSprite(_corner_to_track_sprite[halftile_corner] + rti->base_sprites.single_n, PALETTE_CRASH, NULL, 0, -TILE_HEIGHT);
02089     }
02090   }
02091 }
02092 
02098 enum {
02099   SIGNAL_TO_SOUTHWEST =  0,
02100   SIGNAL_TO_NORTHEAST =  2,
02101   SIGNAL_TO_SOUTHEAST =  4,
02102   SIGNAL_TO_NORTHWEST =  6,
02103   SIGNAL_TO_EAST      =  8,
02104   SIGNAL_TO_WEST      = 10,
02105   SIGNAL_TO_SOUTH     = 12,
02106   SIGNAL_TO_NORTH     = 14,
02107 };
02108 
02109 static void DrawSignals(TileIndex tile, TrackBits rails)
02110 {
02111 #define MAYBE_DRAW_SIGNAL(x, y, z, t) if (IsSignalPresent(tile, x)) DrawSingleSignal(tile, t, GetSingleSignalState(tile, x), y, z)
02112 
02113   if (!(rails & TRACK_BIT_Y)) {
02114     if (!(rails & TRACK_BIT_X)) {
02115       if (rails & TRACK_BIT_LEFT) {
02116         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTH, 0, TRACK_LEFT);
02117         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTH, 1, TRACK_LEFT);
02118       }
02119       if (rails & TRACK_BIT_RIGHT) {
02120         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_NORTH, 2, TRACK_RIGHT);
02121         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_SOUTH, 3, TRACK_RIGHT);
02122       }
02123       if (rails & TRACK_BIT_UPPER) {
02124         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_WEST, 4, TRACK_UPPER);
02125         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_EAST, 5, TRACK_UPPER);
02126       }
02127       if (rails & TRACK_BIT_LOWER) {
02128         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_WEST, 6, TRACK_LOWER);
02129         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_EAST, 7, TRACK_LOWER);
02130       }
02131     } else {
02132       MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHWEST, 8, TRACK_X);
02133       MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHEAST, 9, TRACK_X);
02134     }
02135   } else {
02136     MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHEAST, 10, TRACK_Y);
02137     MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHWEST, 11, TRACK_Y);
02138   }
02139 }
02140 
02141 static void DrawTile_Track(TileInfo *ti)
02142 {
02143   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
02144 
02145   _drawtile_track_palette = COMPANY_SPRITE_COLOUR(GetTileOwner(ti->tile));
02146 
02147   if (IsPlainRail(ti->tile)) {
02148     TrackBits rails = GetTrackBits(ti->tile);
02149 
02150     DrawTrackBits(ti, rails);
02151 
02152     if (HasBit(_display_opt, DO_FULL_DETAIL)) DrawTrackDetails(ti, rti);
02153 
02154     if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
02155 
02156     if (HasSignals(ti->tile)) DrawSignals(ti->tile, rails);
02157   } else {
02158     /* draw depot */
02159     const DrawTileSprites *dts;
02160     PaletteID pal = PAL_NONE;
02161     SpriteID relocation;
02162 
02163     if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);
02164 
02165     if (IsInvisibilitySet(TO_BUILDINGS)) {
02166       /* Draw rail instead of depot */
02167       dts = &_depot_invisible_gfx_table[GetRailDepotDirection(ti->tile)];
02168     } else {
02169       dts = &_depot_gfx_table[GetRailDepotDirection(ti->tile)];
02170     }
02171 
02172     SpriteID image;
02173     if (rti->UsesOverlay()) {
02174       image = SPR_FLAT_GRASS_TILE;
02175     } else {
02176       image = dts->ground.sprite;
02177       if (image != SPR_FLAT_GRASS_TILE) image += rti->total_offset;
02178     }
02179 
02180     /* adjust ground tile for desert
02181      * don't adjust for snow, because snow in depots looks weird */
02182     if (IsSnowRailGround(ti->tile) && _settings_game.game_creation.landscape == LT_TROPIC) {
02183       if (image != SPR_FLAT_GRASS_TILE) {
02184         image += rti->snow_offset; // tile with tracks
02185       } else {
02186         image = SPR_FLAT_SNOW_DESERT_TILE; // flat ground
02187       }
02188     }
02189 
02190     DrawGroundSprite(image, GroundSpritePaletteTransform(image, pal, _drawtile_track_palette));
02191 
02192     if (rti->UsesOverlay()) {
02193       SpriteID ground = GetCustomRailSprite(rti, ti->tile, RTSG_GROUND);
02194 
02195       switch (GetRailDepotDirection(ti->tile)) {
02196         case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02197         case DIAGDIR_SW: DrawGroundSprite(ground + RTO_X, PAL_NONE); break;
02198         case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02199         case DIAGDIR_SE: DrawGroundSprite(ground + RTO_Y, PAL_NONE); break;
02200         default: break;
02201       }
02202 
02203       if (_settings_client.gui.show_track_reservation && HasDepotReservation(ti->tile)) {
02204         SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
02205 
02206         switch (GetRailDepotDirection(ti->tile)) {
02207           case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02208           case DIAGDIR_SW: DrawGroundSprite(overlay + RTO_X, PALETTE_CRASH); break;
02209           case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02210           case DIAGDIR_SE: DrawGroundSprite(overlay + RTO_Y, PALETTE_CRASH); break;
02211           default: break;
02212         }
02213       }
02214 
02215       relocation  = GetCustomRailSprite(rti, ti->tile, RTSG_DEPOT);
02216       relocation -= SPR_RAIL_DEPOT_SE_1;
02217     } else {
02218       /* PBS debugging, draw reserved tracks darker */
02219       if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasDepotReservation(ti->tile)) {
02220         switch (GetRailDepotDirection(ti->tile)) {
02221           case DIAGDIR_NE: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02222           case DIAGDIR_SW: DrawGroundSprite(rti->base_sprites.single_x, PALETTE_CRASH); break;
02223           case DIAGDIR_NW: if (!IsInvisibilitySet(TO_BUILDINGS)) break; // else FALL THROUGH
02224           case DIAGDIR_SE: DrawGroundSprite(rti->base_sprites.single_y, PALETTE_CRASH); break;
02225           default: break;
02226         }
02227       }
02228 
02229       relocation = rti->total_offset;
02230     }
02231 
02232     if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
02233 
02234     DrawRailTileSeq(ti, dts, TO_BUILDINGS, relocation, 0, _drawtile_track_palette);
02235   }
02236   DrawBridgeMiddle(ti);
02237 }
02238 
02239 void DrawTrainDepotSprite(int x, int y, int dir, RailType railtype)
02240 {
02241   const DrawTileSprites *dts = &_depot_gfx_table[dir];
02242   const RailtypeInfo *rti = GetRailTypeInfo(railtype);
02243   SpriteID image = rti->UsesOverlay() ? SPR_FLAT_GRASS_TILE : dts->ground.sprite;
02244   uint32 offset = rti->total_offset;
02245 
02246   x += 33;
02247   y += 17;
02248 
02249   if (image != SPR_FLAT_GRASS_TILE) image += offset;
02250   PaletteID palette = COMPANY_SPRITE_COLOUR(_local_company);
02251 
02252   DrawSprite(image, PAL_NONE, x, y);
02253 
02254   if (rti->UsesOverlay()) {
02255     SpriteID ground = GetCustomRailSprite(rti, INVALID_TILE, RTSG_GROUND);
02256 
02257     switch (dir) {
02258       case DIAGDIR_SW: DrawSprite(ground + RTO_X, PAL_NONE, x, y); break;
02259       case DIAGDIR_SE: DrawSprite(ground + RTO_Y, PAL_NONE, x, y); break;
02260       default: break;
02261     }
02262 
02263     offset  = GetCustomRailSprite(rti, INVALID_TILE, RTSG_DEPOT);
02264     offset -= SPR_RAIL_DEPOT_SE_1;
02265   }
02266 
02267   DrawRailTileSeqInGUI(x, y, dts, offset, 0, palette);
02268 }
02269 
02270 static uint GetSlopeZ_Track(TileIndex tile, uint x, uint y)
02271 {
02272   uint z;
02273   Slope tileh = GetTileSlope(tile, &z);
02274 
02275   if (tileh == SLOPE_FLAT) return z;
02276   if (IsPlainRail(tile)) {
02277     z += ApplyFoundationToSlope(GetRailFoundation(tileh, GetTrackBits(tile)), &tileh);
02278     return z + GetPartialZ(x & 0xF, y & 0xF, tileh);
02279   } else {
02280     return z + TILE_HEIGHT;
02281   }
02282 }
02283 
02284 static Foundation GetFoundation_Track(TileIndex tile, Slope tileh)
02285 {
02286   return IsPlainRail(tile) ? GetRailFoundation(tileh, GetTrackBits(tile)) : FlatteningFoundation(tileh);
02287 }
02288 
02289 static void TileLoop_Track(TileIndex tile)
02290 {
02291   RailGroundType old_ground = GetRailGroundType(tile);
02292   RailGroundType new_ground;
02293 
02294   if (old_ground == RAIL_GROUND_WATER) {
02295     TileLoop_Water(tile);
02296     return;
02297   }
02298 
02299   switch (_settings_game.game_creation.landscape) {
02300     case LT_ARCTIC: {
02301       uint z;
02302       Slope slope = GetTileSlope(tile, &z);
02303       bool half = false;
02304 
02305       /* for non-flat track, use lower part of track
02306        * in other cases, use the highest part with track */
02307       if (IsPlainRail(tile)) {
02308         TrackBits track = GetTrackBits(tile);
02309         Foundation f = GetRailFoundation(slope, track);
02310 
02311         switch (f) {
02312           case FOUNDATION_NONE:
02313             /* no foundation - is the track on the upper side of three corners raised tile? */
02314             if (IsSlopeWithThreeCornersRaised(slope)) z += TILE_HEIGHT;
02315             break;
02316 
02317           case FOUNDATION_INCLINED_X:
02318           case FOUNDATION_INCLINED_Y:
02319             /* sloped track - is it on a steep slope? */
02320             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
02321             break;
02322 
02323           case FOUNDATION_STEEP_LOWER:
02324             /* only lower part of steep slope */
02325             z += TILE_HEIGHT;
02326             break;
02327 
02328           default:
02329             /* if it is a steep slope, then there is a track on higher part */
02330             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
02331             z += TILE_HEIGHT;
02332             break;
02333         }
02334 
02335         half = IsInsideMM(f, FOUNDATION_STEEP_BOTH, FOUNDATION_HALFTILE_N + 1);
02336       } else {
02337         /* is the depot on a non-flat tile? */
02338         if (slope != SLOPE_FLAT) z += TILE_HEIGHT;
02339       }
02340 
02341       /* 'z' is now the lowest part of the highest track bit -
02342        * for sloped track, it is 'z' of lower part
02343        * for two track bits, it is 'z' of higher track bit
02344        * For non-continuous foundations (and STEEP_BOTH), 'half' is set */
02345       if (z > GetSnowLine()) {
02346         if (half && z - GetSnowLine() == TILE_HEIGHT) {
02347           /* track on non-continuous foundation, lower part is not under snow */
02348           new_ground = RAIL_GROUND_HALF_SNOW;
02349         } else {
02350           new_ground = RAIL_GROUND_ICE_DESERT;
02351         }
02352         goto set_ground;
02353       }
02354       break;
02355       }
02356 
02357     case LT_TROPIC:
02358       if (GetTropicZone(tile) == TROPICZONE_DESERT) {
02359         new_ground = RAIL_GROUND_ICE_DESERT;
02360         goto set_ground;
02361       }
02362       break;
02363   }
02364 
02365   if (!IsPlainRail(tile)) return;
02366 
02367   new_ground = RAIL_GROUND_GRASS;
02368 
02369   if (old_ground != RAIL_GROUND_BARREN) { // wait until bottom is green
02370     /* determine direction of fence */
02371     TrackBits rail = GetTrackBits(tile);
02372 
02373     switch (rail) {
02374       case TRACK_BIT_UPPER: new_ground = RAIL_GROUND_FENCE_HORIZ1; break;
02375       case TRACK_BIT_LOWER: new_ground = RAIL_GROUND_FENCE_HORIZ2; break;
02376       case TRACK_BIT_LEFT:  new_ground = RAIL_GROUND_FENCE_VERT1;  break;
02377       case TRACK_BIT_RIGHT: new_ground = RAIL_GROUND_FENCE_VERT2;  break;
02378 
02379       default: {
02380         Owner owner = GetTileOwner(tile);
02381 
02382         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_RIGHT) || (
02383               (rail & TRACK_BIT_3WAY_NW) == 0 &&
02384               (rail & TRACK_BIT_X)
02385             )) {
02386           TileIndex n = tile + TileDiffXY(0, -1);
02387           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02388 
02389           if (!IsTileType(n, MP_RAILWAY) ||
02390               !IsTileOwner(n, owner) ||
02391               nrail == TRACK_BIT_UPPER ||
02392               nrail == TRACK_BIT_LEFT) {
02393             new_ground = RAIL_GROUND_FENCE_NW;
02394           }
02395         }
02396 
02397         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_LEFT) || (
02398               (rail & TRACK_BIT_3WAY_SE) == 0 &&
02399               (rail & TRACK_BIT_X)
02400             )) {
02401           TileIndex n = tile + TileDiffXY(0, 1);
02402           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02403 
02404           if (!IsTileType(n, MP_RAILWAY) ||
02405               !IsTileOwner(n, owner) ||
02406               nrail == TRACK_BIT_LOWER ||
02407               nrail == TRACK_BIT_RIGHT) {
02408             new_ground = (new_ground == RAIL_GROUND_FENCE_NW) ?
02409               RAIL_GROUND_FENCE_SENW : RAIL_GROUND_FENCE_SE;
02410           }
02411         }
02412 
02413         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_LEFT) || (
02414               (rail & TRACK_BIT_3WAY_NE) == 0 &&
02415               (rail & TRACK_BIT_Y)
02416             )) {
02417           TileIndex n = tile + TileDiffXY(-1, 0);
02418           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02419 
02420           if (!IsTileType(n, MP_RAILWAY) ||
02421               !IsTileOwner(n, owner) ||
02422               nrail == TRACK_BIT_UPPER ||
02423               nrail == TRACK_BIT_RIGHT) {
02424             new_ground = RAIL_GROUND_FENCE_NE;
02425           }
02426         }
02427 
02428         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_RIGHT) || (
02429               (rail & TRACK_BIT_3WAY_SW) == 0 &&
02430               (rail & TRACK_BIT_Y)
02431             )) {
02432           TileIndex n = tile + TileDiffXY(1, 0);
02433           TrackBits nrail = (IsPlainRailTile(n) ? GetTrackBits(n) : TRACK_BIT_NONE);
02434 
02435           if (!IsTileType(n, MP_RAILWAY) ||
02436               !IsTileOwner(n, owner) ||
02437               nrail == TRACK_BIT_LOWER ||
02438               nrail == TRACK_BIT_LEFT) {
02439             new_ground = (new_ground == RAIL_GROUND_FENCE_NE) ?
02440               RAIL_GROUND_FENCE_NESW : RAIL_GROUND_FENCE_SW;
02441           }
02442         }
02443         break;
02444       }
02445     }
02446   }
02447 
02448 set_ground:
02449   if (old_ground != new_ground) {
02450     SetRailGroundType(tile, new_ground);
02451     MarkTileDirtyByTile(tile);
02452   }
02453 }
02454 
02455 
02456 static TrackStatus GetTileTrackStatus_Track(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
02457 {
02458   /* Case of half tile slope with water. */
02459   if (mode == TRANSPORT_WATER && IsPlainRail(tile) && GetRailGroundType(tile) == RAIL_GROUND_WATER) {
02460     TrackBits tb = GetTrackBits(tile);
02461     switch (tb) {
02462       default: NOT_REACHED();
02463       case TRACK_BIT_UPPER: tb = TRACK_BIT_LOWER; break;
02464       case TRACK_BIT_LOWER: tb = TRACK_BIT_UPPER; break;
02465       case TRACK_BIT_LEFT:  tb = TRACK_BIT_RIGHT; break;
02466       case TRACK_BIT_RIGHT: tb = TRACK_BIT_LEFT;  break;
02467     }
02468     return CombineTrackStatus(TrackBitsToTrackdirBits(tb), TRACKDIR_BIT_NONE);
02469   }
02470 
02471   if (mode != TRANSPORT_RAIL) return 0;
02472 
02473   TrackBits trackbits = TRACK_BIT_NONE;
02474   TrackdirBits red_signals = TRACKDIR_BIT_NONE;
02475 
02476   switch (GetRailTileType(tile)) {
02477     default: NOT_REACHED();
02478     case RAIL_TILE_NORMAL:
02479       trackbits = GetTrackBits(tile);
02480       break;
02481 
02482     case RAIL_TILE_SIGNALS: {
02483       trackbits = GetTrackBits(tile);
02484       byte a = GetPresentSignals(tile);
02485       uint b = GetSignalStates(tile);
02486 
02487       b &= a;
02488 
02489       /* When signals are not present (in neither direction),
02490        * we pretend them to be green. Otherwise, it depends on
02491        * the signal type. For signals that are only active from
02492        * one side, we set the missing signals explicitely to
02493        * `green'. Otherwise, they implicitely become `red'. */
02494       if (!IsOnewaySignal(tile, TRACK_UPPER) || (a & SignalOnTrack(TRACK_UPPER)) == 0) b |= ~a & SignalOnTrack(TRACK_UPPER);
02495       if (!IsOnewaySignal(tile, TRACK_LOWER) || (a & SignalOnTrack(TRACK_LOWER)) == 0) b |= ~a & SignalOnTrack(TRACK_LOWER);
02496 
02497       if ((b & 0x8) == 0) red_signals |= (TRACKDIR_BIT_LEFT_N | TRACKDIR_BIT_X_NE | TRACKDIR_BIT_Y_SE | TRACKDIR_BIT_UPPER_E);
02498       if ((b & 0x4) == 0) red_signals |= (TRACKDIR_BIT_LEFT_S | TRACKDIR_BIT_X_SW | TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_UPPER_W);
02499       if ((b & 0x2) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_N | TRACKDIR_BIT_LOWER_E);
02500       if ((b & 0x1) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_S | TRACKDIR_BIT_LOWER_W);
02501 
02502       break;
02503     }
02504 
02505     case RAIL_TILE_DEPOT: {
02506       DiagDirection dir = GetRailDepotDirection(tile);
02507 
02508       if (side != INVALID_DIAGDIR && side != dir) break;
02509 
02510       trackbits = DiagDirToDiagTrackBits(dir);
02511       break;
02512     }
02513   }
02514 
02515   return CombineTrackStatus(TrackBitsToTrackdirBits(trackbits), red_signals);
02516 }
02517 
02518 static bool ClickTile_Track(TileIndex tile)
02519 {
02520   if (!IsRailDepot(tile)) return false;
02521 
02522   ShowDepotWindow(tile, VEH_TRAIN);
02523   return true;
02524 }
02525 
02526 static void GetTileDesc_Track(TileIndex tile, TileDesc *td)
02527 {
02528   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(tile));
02529   td->rail_speed = rti->max_speed;
02530   td->owner[0] = GetTileOwner(tile);
02531   switch (GetRailTileType(tile)) {
02532     case RAIL_TILE_NORMAL:
02533       td->str = STR_LAI_RAIL_DESCRIPTION_TRACK;
02534       break;
02535 
02536     case RAIL_TILE_SIGNALS: {
02537       static const StringID signal_type[6][6] = {
02538         {
02539           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_SIGNALS,
02540           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
02541           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_EXITSIGNALS,
02542           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_COMBOSIGNALS,
02543           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PBSSIGNALS,
02544           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_NOENTRYSIGNALS
02545         },
02546         {
02547           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PRESIGNALS,
02548           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRESIGNALS,
02549           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_EXITSIGNALS,
02550           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_COMBOSIGNALS,
02551           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PBSSIGNALS,
02552           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_NOENTRYSIGNALS
02553         },
02554         {
02555           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_EXITSIGNALS,
02556           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_EXITSIGNALS,
02557           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXITSIGNALS,
02558           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_COMBOSIGNALS,
02559           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PBSSIGNALS,
02560           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_NOENTRYSIGNALS
02561         },
02562         {
02563           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_COMBOSIGNALS,
02564           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_COMBOSIGNALS,
02565           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_COMBOSIGNALS,
02566           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBOSIGNALS,
02567           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PBSSIGNALS,
02568           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS
02569         },
02570         {
02571           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_PBSSIGNALS,
02572           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_PBSSIGNALS,
02573           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_PBSSIGNALS,
02574           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_PBSSIGNALS,
02575           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBSSIGNALS,
02576           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS
02577         },
02578         {
02579           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NORMAL_NOENTRYSIGNALS,
02580           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PRE_NOENTRYSIGNALS,
02581           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_EXIT_NOENTRYSIGNALS,
02582           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_COMBO_NOENTRYSIGNALS,
02583           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_PBS_NOENTRYSIGNALS,
02584           STR_LAI_RAIL_DESCRIPTION_TRACK_WITH_NOENTRYSIGNALS
02585         }
02586       };
02587 
02588       SignalType primary_signal;
02589       SignalType secondary_signal;
02590       if (HasSignalOnTrack(tile, TRACK_UPPER)) {
02591         primary_signal = GetSignalType(tile, TRACK_UPPER);
02592         secondary_signal = HasSignalOnTrack(tile, TRACK_LOWER) ? GetSignalType(tile, TRACK_LOWER) : primary_signal;
02593       } else {
02594         secondary_signal = primary_signal = GetSignalType(tile, TRACK_LOWER);
02595       }
02596 
02597       td->str = signal_type[secondary_signal][primary_signal];
02598       break;
02599     }
02600 
02601     case RAIL_TILE_DEPOT:
02602       td->str = STR_LAI_RAIL_DESCRIPTION_TRAIN_DEPOT;
02603       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) {
02604         if (td->rail_speed > 0) {
02605           td->rail_speed = min(td->rail_speed, 61);
02606         } else {
02607           td->rail_speed = 61;
02608         }
02609       }
02610       break;
02611 
02612     default:
02613       NOT_REACHED();
02614   }
02615 }
02616 
02617 static void ChangeTileOwner_Track(TileIndex tile, Owner old_owner, Owner new_owner)
02618 {
02619   if (!IsTileOwner(tile, old_owner)) return;
02620 
02621   if (new_owner != INVALID_OWNER) {
02622     SetTileOwner(tile, new_owner);
02623   } else {
02624     DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR);
02625   }
02626 }
02627 
02628 static const byte _fractcoords_behind[4] = { 0x8F, 0x8, 0x80, 0xF8 };
02629 static const byte _fractcoords_enter[4] = { 0x8A, 0x48, 0x84, 0xA8 };
02630 static const int8 _deltacoord_leaveoffset[8] = {
02631   -1,  0,  1,  0, /* x */
02632    0,  1,  0, -1  /* y */
02633 };
02634 
02635 
02641 int TicksToLeaveDepot(const Train *v)
02642 {
02643   DiagDirection dir = GetRailDepotDirection(v->tile);
02644   int length = v->tcache.cached_veh_length;
02645 
02646   switch (dir) {
02647     case DIAGDIR_NE: return  ((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) - (length + 1)));
02648     case DIAGDIR_SE: return -((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   + (length + 1)));
02649     case DIAGDIR_SW: return -((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) + (length + 1)));
02650     default:
02651     case DIAGDIR_NW: return  ((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   - (length + 1)));
02652   }
02653 
02654   return 0; // make compilers happy
02655 }
02656 
02659 static VehicleEnterTileStatus VehicleEnter_Track(Vehicle *u, TileIndex tile, int x, int y)
02660 {
02661   /* this routine applies only to trains in depot tiles */
02662   if (u->type != VEH_TRAIN || !IsRailDepotTile(tile)) return VETSB_CONTINUE;
02663 
02664   Train *v = Train::From(u);
02665 
02666   /* depot direction */
02667   DiagDirection dir = GetRailDepotDirection(tile);
02668 
02669   /* calculate the point where the following wagon should be activated
02670    * this depends on the length of the current vehicle */
02671   int length = v->tcache.cached_veh_length;
02672 
02673   byte fract_coord_leave =
02674     ((_fractcoords_enter[dir] & 0x0F) + // x
02675       (length + 1) * _deltacoord_leaveoffset[dir]) +
02676     (((_fractcoords_enter[dir] >> 4) +  // y
02677       ((length + 1) * _deltacoord_leaveoffset[dir + 4])) << 4);
02678 
02679   byte fract_coord = (x & 0xF) + ((y & 0xF) << 4);
02680 
02681   if (_fractcoords_behind[dir] == fract_coord) {
02682     /* make sure a train is not entering the tile from behind */
02683     return VETSB_CANNOT_ENTER;
02684   } else if (_fractcoords_enter[dir] == fract_coord) {
02685     if (DiagDirToDir(ReverseDiagDir(dir)) == v->direction) {
02686       /* enter the depot */
02687       v->track = TRACK_BIT_DEPOT,
02688       v->vehstatus |= VS_HIDDEN; // hide it
02689       v->direction = ReverseDir(v->direction);
02690       if (v->Next() == NULL) VehicleEnterDepot(v->First());
02691       v->tile = tile;
02692 
02693       InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02694       return VETSB_ENTERED_WORMHOLE;
02695     }
02696   } else if (fract_coord_leave == fract_coord) {
02697     if (DiagDirToDir(dir) == v->direction) {
02698       /* leave the depot? */
02699       if ((v = v->Next()) != NULL) {
02700         v->vehstatus &= ~VS_HIDDEN;
02701         v->track = (DiagDirToAxis(dir) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y);
02702       }
02703     }
02704   }
02705 
02706   return VETSB_CONTINUE;
02707 }
02708 
02720 static CommandCost TestAutoslopeOnRailTile(TileIndex tile, uint flags, uint z_old, Slope tileh_old, uint z_new, Slope tileh_new, TrackBits rail_bits)
02721 {
02722   if (!_settings_game.construction.build_on_slopes || !AutoslopeEnabled()) return CMD_ERROR;
02723 
02724   /* Is the slope-rail_bits combination valid in general? I.e. is it safe to call GetRailFoundation() ? */
02725   if (CheckRailSlope(tileh_new, rail_bits, TRACK_BIT_NONE, tile).Failed()) return CMD_ERROR;
02726 
02727   /* Get the slopes on top of the foundations */
02728   z_old += ApplyFoundationToSlope(GetRailFoundation(tileh_old, rail_bits), &tileh_old);
02729   z_new += ApplyFoundationToSlope(GetRailFoundation(tileh_new, rail_bits), &tileh_new);
02730 
02731   Corner track_corner;
02732   switch (rail_bits) {
02733     case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
02734     case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
02735     case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
02736     case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
02737 
02738     /* Surface slope must not be changed */
02739     default: return (((z_old != z_new) || (tileh_old != tileh_new)) ? CMD_ERROR : CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]));
02740   }
02741 
02742   /* The height of the track_corner must not be changed. The rest ensures GetRailFoundation() already. */
02743   z_old += GetSlopeZInCorner(RemoveHalftileSlope(tileh_old), track_corner);
02744   z_new += GetSlopeZInCorner(RemoveHalftileSlope(tileh_new), track_corner);
02745   if (z_old != z_new) return CMD_ERROR;
02746 
02747   CommandCost cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
02748   /* Make the ground dirty, if surface slope has changed */
02749   if (tileh_old != tileh_new) {
02750     /* If there is flat water on the lower halftile add the cost for clearing it */
02751     if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old)) cost.AddCost(_price[PR_CLEAR_WATER]);
02752     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
02753   }
02754   return  cost;
02755 }
02756 
02757 static CommandCost TerraformTile_Track(TileIndex tile, DoCommandFlag flags, uint z_new, Slope tileh_new)
02758 {
02759   uint z_old;
02760   Slope tileh_old = GetTileSlope(tile, &z_old);
02761   if (IsPlainRail(tile)) {
02762     TrackBits rail_bits = GetTrackBits(tile);
02763     /* Is there flat water on the lower halftile, that must be cleared expensively? */
02764     bool was_water = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old));
02765 
02766     _error_message = STR_ERROR_MUST_REMOVE_RAILROAD_TRACK;
02767 
02768     /* First test autoslope. However if it succeeds we still have to test the rest, because non-autoslope terraforming is cheaper. */
02769     CommandCost autoslope_result = TestAutoslopeOnRailTile(tile, flags, z_old, tileh_old, z_new, tileh_new, rail_bits);
02770 
02771     /* When there is only a single horizontal/vertical track, one corner can be terraformed. */
02772     Corner allowed_corner;
02773     switch (rail_bits) {
02774       case TRACK_BIT_RIGHT: allowed_corner = CORNER_W; break;
02775       case TRACK_BIT_UPPER: allowed_corner = CORNER_S; break;
02776       case TRACK_BIT_LEFT:  allowed_corner = CORNER_E; break;
02777       case TRACK_BIT_LOWER: allowed_corner = CORNER_N; break;
02778       default: return autoslope_result;
02779     }
02780 
02781     Foundation f_old = GetRailFoundation(tileh_old, rail_bits);
02782 
02783     /* Do not allow terraforming if allowed_corner is part of anti-zig-zag foundations */
02784     if (tileh_old != SLOPE_NS && tileh_old != SLOPE_EW && IsSpecialRailFoundation(f_old)) return autoslope_result;
02785 
02786     /* Everything is valid, which only changes allowed_corner */
02787     for (Corner corner = (Corner)0; corner < CORNER_END; corner = (Corner)(corner + 1)) {
02788       if (allowed_corner == corner) continue;
02789       if (z_old + GetSlopeZInCorner(tileh_old, corner) != z_new + GetSlopeZInCorner(tileh_new, corner)) return autoslope_result;
02790     }
02791 
02792     /* Make the ground dirty */
02793     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
02794 
02795     /* allow terraforming */
02796     return CommandCost(EXPENSES_CONSTRUCTION, was_water ? _price[PR_CLEAR_WATER] : (Money)0);
02797   } else if (_settings_game.construction.build_on_slopes && AutoslopeEnabled() &&
02798       AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRailDepotDirection(tile))) {
02799     return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
02800   }
02801   return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
02802 }
02803 
02804 
02805 extern const TileTypeProcs _tile_type_rail_procs = {
02806   DrawTile_Track,           // draw_tile_proc
02807   GetSlopeZ_Track,          // get_slope_z_proc
02808   ClearTile_Track,          // clear_tile_proc
02809   NULL,                     // add_accepted_cargo_proc
02810   GetTileDesc_Track,        // get_tile_desc_proc
02811   GetTileTrackStatus_Track, // get_tile_track_status_proc
02812   ClickTile_Track,          // click_tile_proc
02813   NULL,                     // animate_tile_proc
02814   TileLoop_Track,           // tile_loop_clear
02815   ChangeTileOwner_Track,    // change_tile_owner_clear
02816   NULL,                     // add_produced_cargo_proc
02817   VehicleEnter_Track,       // vehicle_enter_tile_proc
02818   GetFoundation_Track,      // get_foundation_proc
02819   TerraformTile_Track,      // terraform_tile_proc
02820 };

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