rail_cmd.cpp

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00001 /* $Id: rail_cmd.cpp 14426 2008-10-01 11:48:57Z rubidium $ */
00002 
00005 #include "stdafx.h"
00006 #include "openttd.h"
00007 #include "bridge_map.h"
00008 #include "bridge.h"
00009 #include "cmd_helper.h"
00010 #include "debug.h"
00011 #include "tile_cmd.h"
00012 #include "rail_map.h"
00013 #include "road_map.h"
00014 #include "landscape.h"
00015 #include "town_map.h"
00016 #include "tunnel_map.h"
00017 #include "viewport_func.h"
00018 #include "command_func.h"
00019 #include "pathfind.h"
00020 #include "engine.h"
00021 #include "town.h"
00022 #include "station.h"
00023 #include "sprite.h"
00024 #include "depot.h"
00025 #include "waypoint.h"
00026 #include "rail.h"
00027 #include "newgrf.h"
00028 #include "yapf/yapf.h"
00029 #include "newgrf_engine.h"
00030 #include "newgrf_callbacks.h"
00031 #include "newgrf_station.h"
00032 #include "train.h"
00033 #include "variables.h"
00034 #include "autoslope.h"
00035 #include "transparency.h"
00036 #include "water.h"
00037 #include "tunnelbridge_map.h"
00038 #include "window_func.h"
00039 #include "vehicle_func.h"
00040 #include "sound_func.h"
00041 #include "signal_func.h"
00042 #include "tunnelbridge.h"
00043 
00044 #include "table/sprites.h"
00045 #include "table/strings.h"
00046 #include "table/railtypes.h"
00047 #include "table/track_land.h"
00048 
00049 const byte _track_sloped_sprites[14] = {
00050   14, 15, 22, 13,
00051    0, 21, 17, 12,
00052   23,  0, 18, 20,
00053   19, 16
00054 };
00055 
00056 
00057 /*         4
00058  *     ---------
00059  *    |\       /|
00060  *    | \    1/ |
00061  *    |  \   /  |
00062  *    |   \ /   |
00063  *  16|    \    |32
00064  *    |   / \2  |
00065  *    |  /   \  |
00066  *    | /     \ |
00067  *    |/       \|
00068  *     ---------
00069  *         8
00070  */
00071 
00072 
00073 
00074 /* MAP2 byte:    abcd???? => Signal On? Same coding as map3lo
00075  * MAP3LO byte:  abcd???? => Signal Exists?
00076  *               a and b are for diagonals, upper and left,
00077  *               one for each direction. (ie a == NE->SW, b ==
00078  *               SW->NE, or v.v., I don't know. b and c are
00079  *               similar for lower and right.
00080  * MAP2 byte:    ????abcd => Type of ground.
00081  * MAP3LO byte:  ????abcd => Type of rail.
00082  * MAP5:         00abcdef => rail
00083  *               01abcdef => rail w/ signals
00084  *               10uuuuuu => unused
00085  *               11uuuudd => rail depot
00086  */
00087 
00088 
00089 void *EnsureNoTrainOnTrackProc(Vehicle *v, void *data)
00090 {
00091   TrackBits rail_bits = *(TrackBits *)data;
00092 
00093   if (v->type != VEH_TRAIN) return NULL;
00094 
00095   if ((v->u.rail.track != rail_bits) && !TracksOverlap(v->u.rail.track | rail_bits)) return NULL;
00096 
00097   _error_message = VehicleInTheWayErrMsg(v);
00098   return v;
00099 }
00100 
00108 static bool EnsureNoTrainOnTrack(TileIndex tile, Track track)
00109 {
00110   TrackBits rail_bits = TrackToTrackBits(track);
00111 
00112   return !HasVehicleOnPos(tile, &rail_bits, &EnsureNoTrainOnTrackProc);
00113 }
00114 
00115 static bool CheckTrackCombination(TileIndex tile, TrackBits to_build, uint flags)
00116 {
00117   TrackBits current; // The current track layout
00118   TrackBits future;  // The track layout we want to build
00119   _error_message = STR_1001_IMPOSSIBLE_TRACK_COMBINATION;
00120 
00121   if (!IsPlainRailTile(tile)) return false;
00122 
00123   /* So, we have a tile with tracks on it (and possibly signals). Let's see
00124    * what tracks first */
00125   current = GetTrackBits(tile);
00126   future = current | to_build;
00127 
00128   /* Are we really building something new? */
00129   if (current == future) {
00130     /* Nothing new is being built */
00131     _error_message = STR_1007_ALREADY_BUILT;
00132     return false;
00133   }
00134 
00135   /* Let's see if we may build this */
00136   if (flags & DC_NO_RAIL_OVERLAP || HasSignals(tile)) {
00137     /* If we are not allowed to overlap (flag is on for ai players or we have
00138      * signals on the tile), check that */
00139     return future == TRACK_BIT_HORZ || future == TRACK_BIT_VERT;
00140   } else {
00141     /* Normally, we may overlap and any combination is valid */
00142     return true;
00143   }
00144 }
00145 
00146 
00148 static const TrackBits _valid_tracks_without_foundation[15] = {
00149   TRACK_BIT_ALL,
00150   TRACK_BIT_RIGHT,
00151   TRACK_BIT_UPPER,
00152   TRACK_BIT_X,
00153 
00154   TRACK_BIT_LEFT,
00155   TRACK_BIT_NONE,
00156   TRACK_BIT_Y,
00157   TRACK_BIT_LOWER,
00158 
00159   TRACK_BIT_LOWER,
00160   TRACK_BIT_Y,
00161   TRACK_BIT_NONE,
00162   TRACK_BIT_LEFT,
00163 
00164   TRACK_BIT_X,
00165   TRACK_BIT_UPPER,
00166   TRACK_BIT_RIGHT,
00167 };
00168 
00170 static const TrackBits _valid_tracks_on_leveled_foundation[15] = {
00171   TRACK_BIT_NONE,
00172   TRACK_BIT_LEFT,
00173   TRACK_BIT_LOWER,
00174   TRACK_BIT_Y | TRACK_BIT_LOWER | TRACK_BIT_LEFT,
00175 
00176   TRACK_BIT_RIGHT,
00177   TRACK_BIT_ALL,
00178   TRACK_BIT_X | TRACK_BIT_LOWER | TRACK_BIT_RIGHT,
00179   TRACK_BIT_ALL,
00180 
00181   TRACK_BIT_UPPER,
00182   TRACK_BIT_X | TRACK_BIT_UPPER | TRACK_BIT_LEFT,
00183   TRACK_BIT_ALL,
00184   TRACK_BIT_ALL,
00185 
00186   TRACK_BIT_Y | TRACK_BIT_UPPER | TRACK_BIT_RIGHT,
00187   TRACK_BIT_ALL,
00188   TRACK_BIT_ALL
00189 };
00190 
00198 Foundation GetRailFoundation(Slope tileh, TrackBits bits)
00199 {
00200   if (bits == TRACK_BIT_NONE) return FOUNDATION_NONE;
00201 
00202   if (IsSteepSlope(tileh)) {
00203     /* Test for inclined foundations */
00204     if (bits == TRACK_BIT_X) return FOUNDATION_INCLINED_X;
00205     if (bits == TRACK_BIT_Y) return FOUNDATION_INCLINED_Y;
00206 
00207     /* Get higher track */
00208     Corner highest_corner = GetHighestSlopeCorner(tileh);
00209     TrackBits higher_track = CornerToTrackBits(highest_corner);
00210 
00211     /* Only higher track? */
00212     if (bits == higher_track) return HalftileFoundation(highest_corner);
00213 
00214     /* Overlap with higher track? */
00215     if (TracksOverlap(bits | higher_track)) return FOUNDATION_INVALID;
00216 
00217     /* either lower track or both higher and lower track */
00218     return ((bits & higher_track) != 0 ? FOUNDATION_STEEP_BOTH : FOUNDATION_STEEP_LOWER);
00219   } else {
00220     if ((~_valid_tracks_without_foundation[tileh] & bits) == 0) return FOUNDATION_NONE;
00221 
00222     bool valid_on_leveled = ((~_valid_tracks_on_leveled_foundation[tileh] & bits) == 0);
00223 
00224     Corner track_corner;
00225     switch (bits) {
00226       case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
00227       case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
00228       case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
00229       case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
00230 
00231       case TRACK_BIT_HORZ:
00232         if (tileh == SLOPE_N) return HalftileFoundation(CORNER_N);
00233         if (tileh == SLOPE_S) return HalftileFoundation(CORNER_S);
00234         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00235 
00236       case TRACK_BIT_VERT:
00237         if (tileh == SLOPE_W) return HalftileFoundation(CORNER_W);
00238         if (tileh == SLOPE_E) return HalftileFoundation(CORNER_E);
00239         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00240 
00241       case TRACK_BIT_X:
00242         if (IsSlopeWithOneCornerRaised(tileh)) return FOUNDATION_INCLINED_X;
00243         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00244 
00245       case TRACK_BIT_Y:
00246         if (IsSlopeWithOneCornerRaised(tileh)) return FOUNDATION_INCLINED_Y;
00247         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00248 
00249       default:
00250         return (valid_on_leveled ? FOUNDATION_LEVELED : FOUNDATION_INVALID);
00251     }
00252     /* Single diagonal track */
00253 
00254     /* Track must be at least valid on leveled foundation */
00255     if (!valid_on_leveled) return FOUNDATION_INVALID;
00256 
00257     /* If slope has three raised corners, build leveled foundation */
00258     if (IsSlopeWithThreeCornersRaised(tileh)) return FOUNDATION_LEVELED;
00259 
00260     /* If neighboured corners of track_corner are lowered, build halftile foundation */
00261     if ((tileh & SlopeWithThreeCornersRaised(OppositeCorner(track_corner))) == SlopeWithOneCornerRaised(track_corner)) return HalftileFoundation(track_corner);
00262 
00263     /* else special anti-zig-zag foundation */
00264     return SpecialRailFoundation(track_corner);
00265   }
00266 }
00267 
00268 
00278 static CommandCost CheckRailSlope(Slope tileh, TrackBits rail_bits, TrackBits existing, TileIndex tile)
00279 {
00280   /* don't allow building on the lower side of a coast */
00281   if (IsTileType(tile, MP_WATER) || (IsTileType(tile, MP_RAILWAY) && (GetRailGroundType(tile) == RAIL_GROUND_WATER))) {
00282     if (!IsSteepSlope(tileh) && ((~_valid_tracks_on_leveled_foundation[tileh] & (rail_bits | existing)) != 0)) return_cmd_error(STR_3807_CAN_T_BUILD_ON_WATER);
00283   }
00284 
00285   Foundation f_new = GetRailFoundation(tileh, rail_bits | existing);
00286 
00287   /* check track/slope combination */
00288   if ((f_new == FOUNDATION_INVALID) ||
00289       ((f_new != FOUNDATION_NONE) && (!_patches.build_on_slopes || _is_old_ai_player))
00290      ) return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
00291 
00292   Foundation f_old = GetRailFoundation(tileh, existing);
00293   return CommandCost(EXPENSES_CONSTRUCTION, f_new != f_old ? _price.terraform : (Money)0);
00294 }
00295 
00296 /* Validate functions for rail building */
00297 static inline bool ValParamTrackOrientation(Track track) {return IsValidTrack(track);}
00298 
00305 CommandCost CmdBuildSingleRail(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00306 {
00307   Slope tileh;
00308   RailType railtype = (RailType)p1;
00309   Track track = (Track)p2;
00310   TrackBits trackbit;
00311   CommandCost cost(EXPENSES_CONSTRUCTION);
00312   CommandCost ret;
00313 
00314   if (!ValParamRailtype(railtype) || !ValParamTrackOrientation(track)) return CMD_ERROR;
00315 
00316   tileh = GetTileSlope(tile, NULL);
00317   trackbit = TrackToTrackBits(track);
00318 
00319   switch (GetTileType(tile)) {
00320     case MP_RAILWAY:
00321       if (!CheckTrackCombination(tile, trackbit, flags) ||
00322           !EnsureNoTrainOnTrack(tile, track)) {
00323         return CMD_ERROR;
00324       }
00325       if (!IsTileOwner(tile, _current_player) ||
00326           !IsCompatibleRail(GetRailType(tile), railtype)) {
00327         /* Get detailed error message */
00328         return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00329       }
00330 
00331       ret = CheckRailSlope(tileh, trackbit, GetTrackBits(tile), tile);
00332       if (CmdFailed(ret)) return ret;
00333       cost.AddCost(ret);
00334 
00335       /* If the rail types don't match, try to convert only if engines of
00336        * the present rail type are powered on the new rail type. */
00337       if (GetRailType(tile) != railtype && HasPowerOnRail(GetRailType(tile), railtype)) {
00338         ret = DoCommand(tile, tile, railtype, flags, CMD_CONVERT_RAIL);
00339         if (CmdFailed(ret)) return ret;
00340         cost.AddCost(ret);
00341       }
00342 
00343       if (flags & DC_EXEC) {
00344         SetRailGroundType(tile, RAIL_GROUND_BARREN);
00345         SetTrackBits(tile, GetTrackBits(tile) | trackbit);
00346       }
00347       break;
00348 
00349     case MP_ROAD:
00350 #define M(x) (1 << (x))
00351       /* Level crossings may only be built on these slopes */
00352       if (!HasBit(M(SLOPE_SEN) | M(SLOPE_ENW) | M(SLOPE_NWS) | M(SLOPE_NS) | M(SLOPE_WSE) | M(SLOPE_EW) | M(SLOPE_FLAT), tileh)) {
00353         return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
00354       }
00355 #undef M
00356 
00357       if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
00358 
00359       if (IsNormalRoad(tile)) {
00360         if (HasRoadWorks(tile)) return_cmd_error(STR_ROAD_WORKS_IN_PROGRESS);
00361 
00362         if (GetDisallowedRoadDirections(tile) != DRD_NONE) return_cmd_error(STR_ERR_CROSSING_ON_ONEWAY_ROAD);
00363 
00364         RoadTypes roadtypes = GetRoadTypes(tile);
00365         RoadBits road = GetRoadBits(tile, ROADTYPE_ROAD);
00366         RoadBits tram = GetRoadBits(tile, ROADTYPE_TRAM);
00367         switch (roadtypes) {
00368           default: break;
00369           case ROADTYPES_TRAM:
00370             /* Tram crossings must always have road. */
00371             if (flags & DC_EXEC) SetRoadOwner(tile, ROADTYPE_ROAD, _current_player);
00372             roadtypes |= ROADTYPES_ROAD;
00373             break;
00374 
00375           case ROADTYPES_ROADTRAM: if (road == tram) break;
00376             /* FALL THROUGH */
00377           case ROADTYPES_ROADHWAY: // Road and highway are incompatible in this case
00378           case ROADTYPES_TRAMHWAY: // Tram and highway are incompatible in this case
00379           case ROADTYPES_ALL:      // Also incompatible
00380             return CMD_ERROR;
00381         }
00382 
00383         road |= tram | GetRoadBits(tile, ROADTYPE_HWAY);
00384 
00385         if ((track == TRACK_X && road == ROAD_Y) ||
00386             (track == TRACK_Y && road == ROAD_X)) {
00387           if (flags & DC_EXEC) {
00388             MakeRoadCrossing(tile, GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM), GetRoadOwner(tile, ROADTYPE_HWAY), _current_player, (track == TRACK_X ? AXIS_Y : AXIS_X), railtype, roadtypes, GetTownIndex(tile));
00389             UpdateLevelCrossing(tile, false);
00390           }
00391           break;
00392         }
00393       }
00394 
00395       if (IsLevelCrossing(tile) && GetCrossingRailBits(tile) == trackbit) {
00396         return_cmd_error(STR_1007_ALREADY_BUILT);
00397       }
00398       /* FALLTHROUGH */
00399 
00400     default:
00401       /* Will there be flat water on the lower halftile? */
00402       bool water_ground = IsTileType(tile, MP_WATER) && IsSlopeWithOneCornerRaised(tileh);
00403 
00404       ret = CheckRailSlope(tileh, trackbit, TRACK_BIT_NONE, tile);
00405       if (CmdFailed(ret)) return ret;
00406       cost.AddCost(ret);
00407 
00408       ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00409       if (CmdFailed(ret)) return ret;
00410       cost.AddCost(ret);
00411 
00412       if (water_ground) {
00413         cost.AddCost(-_price.clear_water);
00414         cost.AddCost(_price.clear_roughland);
00415       }
00416 
00417       if (flags & DC_EXEC) {
00418         MakeRailNormal(tile, _current_player, trackbit, railtype);
00419         if (water_ground) SetRailGroundType(tile, RAIL_GROUND_WATER);
00420       }
00421       break;
00422   }
00423 
00424   if (flags & DC_EXEC) {
00425     MarkTileDirtyByTile(tile);
00426     AddTrackToSignalBuffer(tile, track, _current_player);
00427     YapfNotifyTrackLayoutChange(tile, track);
00428   }
00429 
00430   return cost.AddCost(RailBuildCost(railtype));
00431 }
00432 
00439 CommandCost CmdRemoveSingleRail(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00440 {
00441   Track track = (Track)p2;
00442   TrackBits trackbit;
00443   CommandCost cost(EXPENSES_CONSTRUCTION, _price.remove_rail );
00444   bool crossing = false;
00445 
00446   if (!ValParamTrackOrientation((Track)p2)) return CMD_ERROR;
00447   trackbit = TrackToTrackBits(track);
00448 
00449   /* Need to read tile owner now because it may change when the rail is removed
00450    * Also, in case of floods, _current_player != owner
00451    * There may be invalid tiletype even in exec run (when removing long track),
00452    * so do not call GetTileOwner(tile) in any case here */
00453   Owner owner = INVALID_OWNER;
00454 
00455   switch (GetTileType(tile)) {
00456     case MP_ROAD: {
00457       if (!IsLevelCrossing(tile) ||
00458           GetCrossingRailBits(tile) != trackbit ||
00459           (_current_player != OWNER_WATER && !CheckTileOwnership(tile)) ||
00460           (!(flags & DC_BANKRUPT) && !EnsureNoVehicleOnGround(tile))) {
00461         return CMD_ERROR;
00462       }
00463 
00464       if (flags & DC_EXEC) {
00465         owner = GetTileOwner(tile);
00466         MakeRoadNormal(tile, GetCrossingRoadBits(tile), GetRoadTypes(tile), GetTownIndex(tile), GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM), GetRoadOwner(tile, ROADTYPE_HWAY));
00467       }
00468       break;
00469     }
00470 
00471     case MP_RAILWAY: {
00472       TrackBits present;
00473 
00474       if (!IsPlainRailTile(tile) ||
00475           (_current_player != OWNER_WATER && !CheckTileOwnership(tile)) ||
00476           !EnsureNoTrainOnTrack(tile, track)) {
00477         return CMD_ERROR;
00478       }
00479 
00480       present = GetTrackBits(tile);
00481       if ((present & trackbit) == 0) return CMD_ERROR;
00482       if (present == (TRACK_BIT_X | TRACK_BIT_Y)) crossing = true;
00483 
00484       /* Charge extra to remove signals on the track, if they are there */
00485       if (HasSignalOnTrack(tile, track))
00486         cost.AddCost(DoCommand(tile, track, 0, flags, CMD_REMOVE_SIGNALS));
00487 
00488       if (flags & DC_EXEC) {
00489         owner = GetTileOwner(tile);
00490         present ^= trackbit;
00491         if (present == 0) {
00492           Slope tileh = GetTileSlope(tile, NULL);
00493           /* If there is flat water on the lower halftile, convert the tile to shore so the water remains */
00494           if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh)) {
00495             MakeShore(tile);
00496           } else {
00497             DoClearSquare(tile);
00498           }
00499         } else {
00500           SetTrackBits(tile, present);
00501         }
00502       }
00503       break;
00504     }
00505 
00506     default: return CMD_ERROR;
00507   }
00508 
00509   if (flags & DC_EXEC) {
00510     /* if we got that far, 'owner' variable is set correctly */
00511     assert(IsValidPlayer(owner));
00512 
00513     MarkTileDirtyByTile(tile);
00514     if (crossing) {
00515       /* crossing is set when only TRACK_BIT_X and TRACK_BIT_Y are set. As we
00516        * are removing one of these pieces, we'll need to update signals for
00517        * both directions explicitly, as after the track is removed it won't
00518        * 'connect' with the other piece. */
00519       AddTrackToSignalBuffer(tile, TRACK_X, owner);
00520       AddTrackToSignalBuffer(tile, TRACK_Y, owner);
00521       YapfNotifyTrackLayoutChange(tile, TRACK_X);
00522       YapfNotifyTrackLayoutChange(tile, TRACK_Y);
00523     } else {
00524       AddTrackToSignalBuffer(tile, track, owner);
00525       YapfNotifyTrackLayoutChange(tile, track);
00526     }
00527   }
00528 
00529   return cost;
00530 }
00531 
00532 
00540 bool FloodHalftile(TileIndex t)
00541 {
00542   bool flooded = false;
00543   if (GetRailGroundType(t) == RAIL_GROUND_WATER) return flooded;
00544 
00545   Slope tileh = GetTileSlope(t, NULL);
00546   TrackBits rail_bits = GetTrackBits(t);
00547 
00548   if (IsSlopeWithOneCornerRaised(tileh)) {
00549     TrackBits lower_track = CornerToTrackBits(OppositeCorner(GetHighestSlopeCorner(tileh)));
00550 
00551     TrackBits to_remove = lower_track & rail_bits;
00552     if (to_remove != 0) {
00553       _current_player = OWNER_WATER;
00554       if (CmdFailed(DoCommand(t, 0, FIND_FIRST_BIT(to_remove), DC_EXEC, CMD_REMOVE_SINGLE_RAIL))) return flooded; // not yet floodable
00555       flooded = true;
00556       rail_bits = rail_bits & ~to_remove;
00557       if (rail_bits == 0) {
00558         MakeShore(t);
00559         MarkTileDirtyByTile(t);
00560         return flooded;
00561       }
00562     }
00563 
00564     if (IsNonContinuousFoundation(GetRailFoundation(tileh, rail_bits))) {
00565       flooded = true;
00566       SetRailGroundType(t, RAIL_GROUND_WATER);
00567       MarkTileDirtyByTile(t);
00568     }
00569   } else {
00570     /* Make shore on steep slopes and 'three-corners-raised'-slopes. */
00571     if (ApplyFoundationToSlope(GetRailFoundation(tileh, rail_bits), &tileh) == 0) {
00572       if (IsSteepSlope(tileh) || IsSlopeWithThreeCornersRaised(tileh)) {
00573         flooded = true;
00574         SetRailGroundType(t, RAIL_GROUND_WATER);
00575         MarkTileDirtyByTile(t);
00576       }
00577     }
00578   }
00579   return flooded;
00580 }
00581 
00582 static const TileIndexDiffC _trackdelta[] = {
00583   { -1,  0 }, {  0,  1 }, { -1,  0 }, {  0,  1 }, {  1,  0 }, {  0,  1 },
00584   {  0,  0 },
00585   {  0,  0 },
00586   {  1,  0 }, {  0, -1 }, {  0, -1 }, {  1,  0 }, {  0, -1 }, { -1,  0 },
00587   {  0,  0 },
00588   {  0,  0 }
00589 };
00590 
00591 
00592 static CommandCost ValidateAutoDrag(Trackdir *trackdir, TileIndex start, TileIndex end)
00593 {
00594   int x = TileX(start);
00595   int y = TileY(start);
00596   int ex = TileX(end);
00597   int ey = TileY(end);
00598   int dx, dy, trdx, trdy;
00599 
00600   if (!ValParamTrackOrientation(TrackdirToTrack(*trackdir))) return CMD_ERROR;
00601 
00602   /* calculate delta x,y from start to end tile */
00603   dx = ex - x;
00604   dy = ey - y;
00605 
00606   /* calculate delta x,y for the first direction */
00607   trdx = _trackdelta[*trackdir].x;
00608   trdy = _trackdelta[*trackdir].y;
00609 
00610   if (!IsDiagonalTrackdir(*trackdir)) {
00611     trdx += _trackdelta[*trackdir ^ 1].x;
00612     trdy += _trackdelta[*trackdir ^ 1].y;
00613   }
00614 
00615   /* validate the direction */
00616   while (
00617     (trdx <= 0 && dx > 0) ||
00618     (trdx >= 0 && dx < 0) ||
00619     (trdy <= 0 && dy > 0) ||
00620     (trdy >= 0 && dy < 0)
00621   ) {
00622     if (!HasBit(*trackdir, 3)) { // first direction is invalid, try the other
00623       SetBit(*trackdir, 3); // reverse the direction
00624       trdx = -trdx;
00625       trdy = -trdy;
00626     } else { // other direction is invalid too, invalid drag
00627       return CMD_ERROR;
00628     }
00629   }
00630 
00631   /* (for diagonal tracks, this is already made sure of by above test), but:
00632    * for non-diagonal tracks, check if the start and end tile are on 1 line */
00633   if (!IsDiagonalTrackdir(*trackdir)) {
00634     trdx = _trackdelta[*trackdir].x;
00635     trdy = _trackdelta[*trackdir].y;
00636     if (abs(dx) != abs(dy) && abs(dx) + abs(trdy) != abs(dy) + abs(trdx))
00637       return CMD_ERROR;
00638   }
00639 
00640   return CommandCost();
00641 }
00642 
00652 static CommandCost CmdRailTrackHelper(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00653 {
00654   CommandCost ret, total_cost(EXPENSES_CONSTRUCTION);
00655   Track track = (Track)GB(p2, 4, 3);
00656   Trackdir trackdir;
00657   byte mode = HasBit(p2, 7);
00658   RailType railtype = (RailType)GB(p2, 0, 4);
00659   TileIndex end_tile;
00660 
00661   if (!ValParamRailtype(railtype) || !ValParamTrackOrientation(track)) return CMD_ERROR;
00662   if (p1 >= MapSize()) return CMD_ERROR;
00663   end_tile = p1;
00664   trackdir = TrackToTrackdir(track);
00665 
00666   if (CmdFailed(ValidateAutoDrag(&trackdir, tile, end_tile))) return CMD_ERROR;
00667 
00668   if (flags & DC_EXEC) SndPlayTileFx(SND_20_SPLAT_2, tile);
00669 
00670   for (;;) {
00671     ret = DoCommand(tile, railtype, TrackdirToTrack(trackdir), flags, (mode == 0) ? CMD_BUILD_SINGLE_RAIL : CMD_REMOVE_SINGLE_RAIL);
00672 
00673     if (CmdFailed(ret)) {
00674       if ((_error_message != STR_1007_ALREADY_BUILT) && (mode == 0)) break;
00675       _error_message = INVALID_STRING_ID;
00676     } else {
00677       total_cost.AddCost(ret);
00678     }
00679 
00680     if (tile == end_tile) break;
00681 
00682     tile += ToTileIndexDiff(_trackdelta[trackdir]);
00683 
00684     /* toggle railbit for the non-diagonal tracks */
00685     if (!IsDiagonalTrackdir(trackdir)) ToggleBit(trackdir, 0);
00686   }
00687 
00688   return (total_cost.GetCost() == 0) ? CMD_ERROR : total_cost;
00689 }
00690 
00702 CommandCost CmdBuildRailroadTrack(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00703 {
00704   return CmdRailTrackHelper(tile, flags, p1, ClrBit(p2, 7));
00705 }
00706 
00718 CommandCost CmdRemoveRailroadTrack(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00719 {
00720   return CmdRailTrackHelper(tile, flags, p1, SetBit(p2, 7));
00721 }
00722 
00732 CommandCost CmdBuildTrainDepot(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00733 {
00734   Slope tileh;
00735 
00736   /* check railtype and valid direction for depot (0 through 3), 4 in total */
00737   if (!ValParamRailtype((RailType)p1)) return CMD_ERROR;
00738 
00739   tileh = GetTileSlope(tile, NULL);
00740 
00741   DiagDirection dir = Extract<DiagDirection, 0>(p2);
00742 
00743   /* Prohibit construction if
00744    * The tile is non-flat AND
00745    * 1) The AI is "old-school"
00746    * 2) build-on-slopes is disabled
00747    * 3) the tile is steep i.e. spans two height levels
00748    * 4) the exit points in the wrong direction
00749    */
00750 
00751   if (tileh != SLOPE_FLAT && (
00752         _is_old_ai_player ||
00753         !_patches.build_on_slopes ||
00754         IsSteepSlope(tileh) ||
00755         !CanBuildDepotByTileh(dir, tileh)
00756       )) {
00757     return_cmd_error(STR_0007_FLAT_LAND_REQUIRED);
00758   }
00759 
00760   CommandCost cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00761   if (CmdFailed(cost)) return CMD_ERROR;
00762 
00763   if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
00764 
00765   if (!Depot::CanAllocateItem()) return CMD_ERROR;
00766 
00767   if (flags & DC_EXEC) {
00768     Depot *d = new Depot(tile);
00769     MakeRailDepot(tile, _current_player, dir, (RailType)p1);
00770     MarkTileDirtyByTile(tile);
00771 
00772     d->town_index = ClosestTownFromTile(tile, (uint)-1)->index;
00773 
00774     AddSideToSignalBuffer(tile, INVALID_DIAGDIR, _current_player);
00775     YapfNotifyTrackLayoutChange(tile, TrackdirToTrack(DiagdirToDiagTrackdir(dir)));
00776   }
00777 
00778   return cost.AddCost(_price.build_train_depot);
00779 }
00780 
00795 CommandCost CmdBuildSingleSignal(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00796 {
00797   Track track = (Track)GB(p1, 0, 3);
00798   bool ctrl_pressed = HasBit(p1, 3); // was the CTRL button pressed
00799   SignalVariant sigvar = (ctrl_pressed ^ HasBit(p1, 4)) ? SIG_SEMAPHORE : SIG_ELECTRIC; // the signal variant of the new signal
00800   SignalType sigtype = (SignalType)GB(p1, 5, 2); // the signal type of the new signal
00801   bool convert_signal = HasBit(p1, 7); // convert button pressed
00802   CommandCost cost;
00803 
00804   if (!ValParamTrackOrientation(track) || !IsTileType(tile, MP_RAILWAY) || !EnsureNoTrainOnTrack(tile, track))
00805     return CMD_ERROR;
00806 
00807   /* Protect against invalid signal copying */
00808   if (p2 != 0 && (p2 & SignalOnTrack(track)) == 0) return CMD_ERROR;
00809 
00810   /* You can only build signals on plain rail tiles, and the selected track must exist */
00811   if (!IsPlainRailTile(tile) || !HasTrack(tile, track)) return CMD_ERROR;
00812 
00813   if (!CheckTileOwnership(tile)) return CMD_ERROR;
00814 
00815   {
00816     /* See if this is a valid track combination for signals, (ie, no overlap) */
00817     TrackBits trackbits = GetTrackBits(tile);
00818     if (KillFirstBit(trackbits) != TRACK_BIT_NONE && /* More than one track present */
00819         trackbits != TRACK_BIT_HORZ &&
00820         trackbits != TRACK_BIT_VERT) {
00821       return_cmd_error(STR_1005_NO_SUITABLE_RAILROAD_TRACK);
00822     }
00823   }
00824 
00825   /* you can not convert a signal if no signal is on track */
00826   if (convert_signal && !HasSignalOnTrack(tile, track)) return CMD_ERROR;
00827 
00828   if (!HasSignalOnTrack(tile, track)) {
00829     /* build new signals */
00830     cost = CommandCost(EXPENSES_CONSTRUCTION, _price.build_signals);
00831   } else {
00832     if (p2 != 0 && sigvar != GetSignalVariant(tile, track)) {
00833       /* convert signals <-> semaphores */
00834       cost = CommandCost(EXPENSES_CONSTRUCTION, _price.build_signals + _price.remove_signals);
00835 
00836     } else if (convert_signal) {
00837       /* convert button pressed */
00838       if (ctrl_pressed || GetSignalVariant(tile, track) != sigvar) {
00839         /* convert electric <-> semaphore */
00840         cost = CommandCost(EXPENSES_CONSTRUCTION, _price.build_signals + _price.remove_signals);
00841       } else {
00842         /* it is free to change signal type: normal-pre-exit-combo */
00843         cost = CommandCost();
00844       }
00845 
00846     } else {
00847       /* it is free to change orientation/pre-exit-combo signals */
00848       cost = CommandCost();
00849     }
00850   }
00851 
00852   if (flags & DC_EXEC) {
00853     if (!HasSignals(tile)) {
00854       /* there are no signals at all on this tile yet */
00855       SetHasSignals(tile, true);
00856       SetSignalStates(tile, 0xF); // all signals are on
00857       SetPresentSignals(tile, 0); // no signals built by default
00858       SetSignalType(tile, track, sigtype);
00859       SetSignalVariant(tile, track, sigvar);
00860     }
00861 
00862     if (p2 == 0) {
00863       if (!HasSignalOnTrack(tile, track)) {
00864         /* build new signals */
00865         SetPresentSignals(tile, GetPresentSignals(tile) | SignalOnTrack(track));
00866         SetSignalType(tile, track, sigtype);
00867         SetSignalVariant(tile, track, sigvar);
00868       } else {
00869         if (convert_signal) {
00870           /* convert signal button pressed */
00871           if (ctrl_pressed) {
00872             /* toggle the pressent signal variant: SIG_ELECTRIC <-> SIG_SEMAPHORE */
00873             SetSignalVariant(tile, track, (GetSignalVariant(tile, track) == SIG_ELECTRIC) ? SIG_SEMAPHORE : SIG_ELECTRIC);
00874 
00875           } else {
00876             /* convert the present signal to the chosen type and variant */
00877             SetSignalType(tile, track, sigtype);
00878             SetSignalVariant(tile, track, sigvar);
00879           }
00880 
00881         } else if (ctrl_pressed) {
00882           /* cycle between normal -> pre -> exit -> combo -> ... */
00883           sigtype = GetSignalType(tile, track);
00884 
00885           SetSignalType(tile, track, sigtype == SIGTYPE_COMBO ? SIGTYPE_NORMAL : (SignalType)(sigtype + 1));
00886         } else {
00887           /* cycle the signal side: both -> left -> right -> both -> ... */
00888           CycleSignalSide(tile, track);
00889         }
00890       }
00891     } else {
00892       /* If CmdBuildManySignals is called with copying signals, just copy the
00893        * direction of the first signal given as parameter by CmdBuildManySignals */
00894       SetPresentSignals(tile, (GetPresentSignals(tile) & ~SignalOnTrack(track)) | (p2 & SignalOnTrack(track)));
00895       SetSignalVariant(tile, track, sigvar);
00896     }
00897 
00898     MarkTileDirtyByTile(tile);
00899     AddTrackToSignalBuffer(tile, track, _current_player);
00900     YapfNotifyTrackLayoutChange(tile, track);
00901   }
00902 
00903   return cost;
00904 }
00905 
00906 static bool CheckSignalAutoFill(TileIndex &tile, Trackdir &trackdir, int &signal_ctr, bool remove)
00907 {
00908   tile = AddTileIndexDiffCWrap(tile, _trackdelta[trackdir]);
00909   if (tile == INVALID_TILE) return false;
00910 
00911   /* Check for track bits on the new tile */
00912   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0));
00913 
00914   if (TracksOverlap(TrackdirBitsToTrackBits(trackdirbits))) return false;
00915   trackdirbits &= TrackdirReachesTrackdirs(trackdir);
00916 
00917   /* No track bits, must stop */
00918   if (trackdirbits == TRACKDIR_BIT_NONE) return false;
00919 
00920   /* Get the first track dir */
00921   trackdir = RemoveFirstTrackdir(&trackdirbits);
00922 
00923   /* Any left? It's a junction so we stop */
00924   if (trackdirbits != TRACKDIR_BIT_NONE) return false;
00925 
00926   switch (GetTileType(tile)) {
00927     case MP_RAILWAY:
00928       if (IsRailDepot(tile)) return false;
00929       if (!remove && HasSignalOnTrack(tile, TrackdirToTrack(trackdir))) return false;
00930       signal_ctr++;
00931       if (IsDiagonalTrackdir(trackdir)) {
00932         signal_ctr++;
00933         /* Ensure signal_ctr even so X and Y pieces get signals */
00934         ClrBit(signal_ctr, 0);
00935       }
00936       return true;
00937 
00938     case MP_ROAD:
00939       if (!IsLevelCrossing(tile)) return false;
00940       signal_ctr += 2;
00941       return true;
00942 
00943     case MP_TUNNELBRIDGE: {
00944       TileIndex orig_tile = tile; // backup old value
00945 
00946       if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return false;
00947       if (GetTunnelBridgeDirection(tile) != TrackdirToExitdir(trackdir)) return false;
00948 
00949       /* Skip to end of tunnel or bridge
00950        * note that tile is a parameter by reference, so it must be updated */
00951       tile = GetOtherTunnelBridgeEnd(tile);
00952 
00953       signal_ctr += (GetTunnelBridgeLength(orig_tile, tile) + 2) * 2;
00954       return true;
00955     }
00956 
00957     default: return false;
00958   }
00959 }
00960 
00973 static CommandCost CmdSignalTrackHelper(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00974 {
00975   CommandCost ret, total_cost(EXPENSES_CONSTRUCTION);
00976   int signal_ctr;
00977   byte signals;
00978   bool error = true;
00979   TileIndex end_tile;
00980   TileIndex start_tile = tile;
00981 
00982   Track track = (Track)GB(p2, 0, 3);
00983   bool mode = HasBit(p2, 3);
00984   bool semaphores = HasBit(p2, 4);
00985   bool remove = HasBit(p2, 5);
00986   bool autofill = HasBit(p2, 6);
00987   Trackdir trackdir = TrackToTrackdir(track);
00988   byte signal_density = GB(p2, 24, 8);
00989 
00990   if (p1 >= MapSize()) return CMD_ERROR;
00991   end_tile = p1;
00992   if (signal_density == 0 || signal_density > 20) return CMD_ERROR;
00993 
00994   if (!IsTileType(tile, MP_RAILWAY)) return CMD_ERROR;
00995 
00996   /* for vertical/horizontal tracks, double the given signals density
00997    * since the original amount will be too dense (shorter tracks) */
00998   signal_density *= 2;
00999 
01000   if (CmdFailed(ValidateAutoDrag(&trackdir, tile, end_tile))) return CMD_ERROR;
01001 
01002   track = TrackdirToTrack(trackdir); /* trackdir might have changed, keep track in sync */
01003   Trackdir start_trackdir = trackdir;
01004 
01005   /* Must start on a valid track to be able to avoid loops */
01006   if (!HasTrack(tile, track)) return CMD_ERROR;
01007 
01008   /* copy the signal-style of the first rail-piece if existing */
01009   if (HasSignals(tile)) {
01010     signals = GetPresentSignals(tile) & SignalOnTrack(track);
01011     if (signals == 0) signals = SignalOnTrack(track); /* Can this actually occur? */
01012 
01013     /* copy signal/semaphores style (independent of CTRL) */
01014     semaphores = GetSignalVariant(tile, track) != SIG_ELECTRIC;
01015   } else { // no signals exist, drag a two-way signal stretch
01016     signals = SignalOnTrack(track);
01017   }
01018 
01019   byte signal_dir = 0;
01020   if (signals & SignalAlongTrackdir(trackdir))   SetBit(signal_dir, 0);
01021   if (signals & SignalAgainstTrackdir(trackdir)) SetBit(signal_dir, 1);
01022 
01023   /* signal_ctr         - amount of tiles already processed
01024    * signals_density    - patch setting to put signal on every Nth tile (double space on |, -- tracks)
01025    **********
01026    * trackdir   - trackdir to build with autorail
01027    * semaphores - semaphores or signals
01028    * signals    - is there a signal/semaphore on the first tile, copy its style (two-way/single-way)
01029    *              and convert all others to semaphore/signal
01030    * remove     - 1 remove signals, 0 build signals */
01031   signal_ctr = 0;
01032   for (;;) {
01033     /* only build/remove signals with the specified density */
01034     if ((remove && autofill) || signal_ctr % signal_density == 0) {
01035       uint32 p1 = GB(TrackdirToTrack(trackdir), 0, 3);
01036       SB(p1, 3, 1, mode);
01037       SB(p1, 4, 1, semaphores);
01038 
01039       /* Pick the correct orientation for the track direction */
01040       signals = 0;
01041       if (HasBit(signal_dir, 0)) signals |= SignalAlongTrackdir(trackdir);
01042       if (HasBit(signal_dir, 1)) signals |= SignalAgainstTrackdir(trackdir);
01043 
01044       ret = DoCommand(tile, p1, signals, flags, remove ? CMD_REMOVE_SIGNALS : CMD_BUILD_SIGNALS);
01045 
01046       /* Be user-friendly and try placing signals as much as possible */
01047       if (CmdSucceeded(ret)) {
01048         error = false;
01049         total_cost.AddCost(ret);
01050       }
01051     }
01052 
01053     if (autofill) {
01054       if (!CheckSignalAutoFill(tile, trackdir, signal_ctr, remove)) break;
01055 
01056       /* Prevent possible loops */
01057       if (tile == start_tile && trackdir == start_trackdir) break;
01058     } else {
01059       if (tile == end_tile) break;
01060 
01061       tile += ToTileIndexDiff(_trackdelta[trackdir]);
01062       signal_ctr++;
01063 
01064       /* toggle railbit for the non-diagonal tracks (|, -- tracks) */
01065       if (IsDiagonalTrackdir(trackdir)) {
01066         signal_ctr++;
01067       } else {
01068         ToggleBit(trackdir, 0);
01069       }
01070     }
01071   }
01072 
01073   return error ? CMD_ERROR : total_cost;
01074 }
01075 
01090 CommandCost CmdBuildSignalTrack(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
01091 {
01092   return CmdSignalTrackHelper(tile, flags, p1, p2);
01093 }
01094 
01104 CommandCost CmdRemoveSingleSignal(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
01105 {
01106   Track track = (Track)GB(p1, 0, 3);
01107 
01108   if (!ValParamTrackOrientation(track) ||
01109       !IsTileType(tile, MP_RAILWAY) ||
01110       !HasTrack(tile, track) ||
01111       !EnsureNoTrainOnTrack(tile, track) ||
01112       !HasSignalOnTrack(tile, track)) {
01113     return CMD_ERROR;
01114   }
01115 
01116   /* Only water can remove signals from anyone */
01117   if (_current_player != OWNER_WATER && !CheckTileOwnership(tile)) return CMD_ERROR;
01118 
01119   /* Do it? */
01120   if (flags & DC_EXEC) {
01121     SetPresentSignals(tile, GetPresentSignals(tile) & ~SignalOnTrack(track));
01122 
01123     /* removed last signal from tile? */
01124     if (GetPresentSignals(tile) == 0) {
01125       SetSignalStates(tile, 0);
01126       SetHasSignals(tile, false);
01127       SetSignalVariant(tile, INVALID_TRACK, SIG_ELECTRIC); // remove any possible semaphores
01128     }
01129 
01130     AddTrackToSignalBuffer(tile, track, GetTileOwner(tile));
01131     YapfNotifyTrackLayoutChange(tile, track);
01132 
01133     MarkTileDirtyByTile(tile);
01134   }
01135 
01136   return CommandCost(EXPENSES_CONSTRUCTION, _price.remove_signals);
01137 }
01138 
01153 CommandCost CmdRemoveSignalTrack(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
01154 {
01155   return CmdSignalTrackHelper(tile, flags, p1, SetBit(p2, 5)); // bit 5 is remove bit
01156 }
01157 
01159 void *UpdateTrainPowerProc(Vehicle *v, void *data)
01160 {
01161   /* Similiar checks as in TrainPowerChanged() */
01162 
01163   if (v->type == VEH_TRAIN && !IsArticulatedPart(v)) {
01164     const RailVehicleInfo *rvi = RailVehInfo(v->engine_type);
01165     if (GetVehicleProperty(v, 0x0B, rvi->power) != 0) TrainPowerChanged(v->First());
01166   }
01167 
01168   return NULL;
01169 }
01170 
01178 CommandCost CmdConvertRail(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
01179 {
01180   CommandCost cost(EXPENSES_CONSTRUCTION);
01181   RailType totype = (RailType)p2;
01182 
01183   if (!ValParamRailtype(totype)) return CMD_ERROR;
01184   if (p1 >= MapSize()) return CMD_ERROR;
01185 
01186   uint ex = TileX(tile);
01187   uint ey = TileY(tile);
01188   uint sx = TileX(p1);
01189   uint sy = TileY(p1);
01190 
01191   /* make sure sx,sy are smaller than ex,ey */
01192   if (ex < sx) Swap(ex, sx);
01193   if (ey < sy) Swap(ey, sy);
01194 
01195   _error_message = STR_1005_NO_SUITABLE_RAILROAD_TRACK; // by default, there is no track to convert
01196 
01197   for (uint x = sx; x <= ex; ++x) {
01198     for (uint y = sy; y <= ey; ++y) {
01199       TileIndex tile = TileXY(x, y);
01200       TileType tt = GetTileType(tile);
01201 
01202       /* Check if there is any track on tile */
01203       switch (tt) {
01204         case MP_RAILWAY:
01205           break;
01206         case MP_STATION:
01207           if (!IsRailwayStation(tile)) continue;
01208           break;
01209         case MP_ROAD:
01210           if (!IsLevelCrossing(tile)) continue;
01211           break;
01212         case MP_TUNNELBRIDGE:
01213           if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) continue;
01214           break;
01215         default: continue;
01216       }
01217 
01218       /* Original railtype we are converting from */
01219       RailType type = GetRailType(tile);
01220 
01221       /* Converting to the same type or converting 'hidden' elrail -> rail */
01222       if (type == totype || (_patches.disable_elrails && totype == RAILTYPE_RAIL && type == RAILTYPE_ELECTRIC)) continue;
01223 
01224       /* Trying to convert other's rail */
01225       if (!CheckTileOwnership(tile)) continue;
01226 
01227       /* Vehicle on the tile when not converting Rail <-> ElRail
01228        * Tunnels and bridges have special check later */
01229       if (tt != MP_TUNNELBRIDGE) {
01230         if (!IsCompatibleRail(type, totype) && !EnsureNoVehicleOnGround(tile)) continue;
01231         if (flags & DC_EXEC) { // we can safely convert, too
01232           SetRailType(tile, totype);
01233           MarkTileDirtyByTile(tile);
01234           /* update power of train engines on this tile */
01235           FindVehicleOnPos(tile, NULL, &UpdateTrainPowerProc);
01236         }
01237       }
01238 
01239       switch (tt) {
01240         case MP_RAILWAY:
01241           switch (GetRailTileType(tile)) {
01242             case RAIL_TILE_WAYPOINT:
01243               if (flags & DC_EXEC) {
01244                 /* notify YAPF about the track layout change */
01245                 YapfNotifyTrackLayoutChange(tile, AxisToTrack(GetWaypointAxis(tile)));
01246               }
01247               cost.AddCost(RailConvertCost(type, totype));
01248               break;
01249 
01250             case RAIL_TILE_DEPOT:
01251               if (flags & DC_EXEC) {
01252                 /* notify YAPF about the track layout change */
01253                 YapfNotifyTrackLayoutChange(tile, AxisToTrack(DiagDirToAxis(GetRailDepotDirection(tile))));
01254 
01255                 /* Update build vehicle window related to this depot */
01256                 InvalidateWindowData(WC_VEHICLE_DEPOT, tile);
01257                 InvalidateWindowData(WC_BUILD_VEHICLE, tile);
01258               }
01259               cost.AddCost(RailConvertCost(type, totype));
01260               break;
01261 
01262             default: // RAIL_TILE_NORMAL, RAIL_TILE_SIGNALS
01263               if (flags & DC_EXEC) {
01264                 /* notify YAPF about the track layout change */
01265                 TrackBits tracks = GetTrackBits(tile);
01266                 while (tracks != TRACK_BIT_NONE) {
01267                   YapfNotifyTrackLayoutChange(tile, RemoveFirstTrack(&tracks));
01268                 }
01269               }
01270               cost.AddCost(RailConvertCost(type, totype) * CountBits(GetTrackBits(tile)));
01271               break;
01272           }
01273           break;
01274 
01275         case MP_TUNNELBRIDGE: {
01276           TileIndex endtile = GetOtherTunnelBridgeEnd(tile);
01277 
01278           /* If both ends of tunnel/bridge are in the range, do not try to convert twice -
01279            * it would cause assert because of different test and exec runs */
01280           if (endtile < tile && TileX(endtile) >= sx && TileX(endtile) <= ex &&
01281               TileY(endtile) >= sy && TileY(endtile) <= ey) continue;
01282 
01283           /* When not coverting rail <-> el. rail, any vehicle cannot be in tunnel/bridge */
01284           if (!IsCompatibleRail(GetRailType(tile), totype) &&
01285               HasVehicleOnTunnelBridge(tile, endtile)) continue;
01286 
01287           if (flags & DC_EXEC) {
01288             SetRailType(tile, totype);
01289             SetRailType(endtile, totype);
01290 
01291             FindVehicleOnPos(tile, NULL, &UpdateTrainPowerProc);
01292             FindVehicleOnPos(endtile, NULL, &UpdateTrainPowerProc);
01293 
01294             Track track = AxisToTrack(DiagDirToAxis(GetTunnelBridgeDirection(tile)));
01295 
01296             YapfNotifyTrackLayoutChange(tile, track);
01297             YapfNotifyTrackLayoutChange(endtile, track);
01298 
01299             MarkTileDirtyByTile(tile);
01300             MarkTileDirtyByTile(endtile);
01301 
01302             if (IsBridge(tile)) {
01303               TileIndexDiff delta = TileOffsByDiagDir(GetTunnelBridgeDirection(tile));
01304               TileIndex t = tile + delta;
01305               for (; t != endtile; t += delta) MarkTileDirtyByTile(t); // TODO encapsulate this into a function
01306             }
01307           }
01308 
01309           cost.AddCost((GetTunnelBridgeLength(tile, endtile) + 2) * RailConvertCost(type, totype));
01310         } break;
01311 
01312         default: // MP_STATION, MP_ROAD
01313           if (flags & DC_EXEC) {
01314             Track track = ((tt == MP_STATION) ? GetRailStationTrack(tile) : GetCrossingRailTrack(tile));
01315             YapfNotifyTrackLayoutChange(tile, track);
01316           }
01317 
01318           cost.AddCost(RailConvertCost(type, totype));
01319           break;
01320       }
01321     }
01322   }
01323 
01324   return (cost.GetCost() == 0) ? CMD_ERROR : cost;
01325 }
01326 
01327 static CommandCost RemoveTrainDepot(TileIndex tile, uint32 flags)
01328 {
01329   if (!CheckTileOwnership(tile) && _current_player != OWNER_WATER)
01330     return CMD_ERROR;
01331 
01332   if (!EnsureNoVehicleOnGround(tile))
01333     return CMD_ERROR;
01334 
01335   if (flags & DC_EXEC) {
01336     /* read variables before the depot is removed */
01337     DiagDirection dir = GetRailDepotDirection(tile);
01338     Owner owner = GetTileOwner(tile);
01339 
01340     DoClearSquare(tile);
01341     delete GetDepotByTile(tile);
01342     AddSideToSignalBuffer(tile, dir, owner);
01343     YapfNotifyTrackLayoutChange(tile, TrackdirToTrack(DiagdirToDiagTrackdir(dir)));
01344   }
01345 
01346   return CommandCost(EXPENSES_CONSTRUCTION, _price.remove_train_depot);
01347 }
01348 
01349 static CommandCost ClearTile_Track(TileIndex tile, byte flags)
01350 {
01351   CommandCost cost(EXPENSES_CONSTRUCTION);
01352   CommandCost ret;
01353 
01354   if (flags & DC_AUTO) {
01355     if (!IsTileOwner(tile, _current_player))
01356       return_cmd_error(STR_1024_AREA_IS_OWNED_BY_ANOTHER);
01357 
01358     if (IsPlainRailTile(tile)) {
01359       return_cmd_error(STR_1008_MUST_REMOVE_RAILROAD_TRACK);
01360     } else {
01361       return_cmd_error(STR_2004_BUILDING_MUST_BE_DEMOLISHED);
01362     }
01363   }
01364 
01365   switch (GetRailTileType(tile)) {
01366     case RAIL_TILE_SIGNALS:
01367     case RAIL_TILE_NORMAL: {
01368       Slope tileh = GetTileSlope(tile, NULL);
01369       /* Is there flat water on the lower halftile, that gets cleared expensively? */
01370       bool water_ground = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh));
01371 
01372       TrackBits tracks = GetTrackBits(tile);
01373       while (tracks != TRACK_BIT_NONE) {
01374         Track track = RemoveFirstTrack(&tracks);
01375         ret = DoCommand(tile, 0, track, flags, CMD_REMOVE_SINGLE_RAIL);
01376         if (CmdFailed(ret)) return CMD_ERROR;
01377         cost.AddCost(ret);
01378       }
01379 
01380       /* when bankrupting, don't make water dirty, there could be a ship on lower halftile */
01381       if (water_ground && !(flags & DC_BANKRUPT)) {
01382         if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
01383 
01384         /* The track was removed, and left a coast tile. Now also clear the water. */
01385         if (flags & DC_EXEC) DoClearSquare(tile);
01386         cost.AddCost(_price.clear_water);
01387       }
01388 
01389       return cost;
01390     }
01391 
01392     case RAIL_TILE_DEPOT:
01393       return RemoveTrainDepot(tile, flags);
01394 
01395     case RAIL_TILE_WAYPOINT:
01396       return RemoveTrainWaypoint(tile, flags, false);
01397 
01398     default:
01399       return CMD_ERROR;
01400   }
01401 }
01402 
01407 static uint GetSaveSlopeZ(uint x, uint y, Track track)
01408 {
01409   switch (track) {
01410     case TRACK_UPPER: x &= ~0xF; y &= ~0xF; break;
01411     case TRACK_LOWER: x |=  0xF; y |=  0xF; break;
01412     case TRACK_LEFT:  x |=  0xF; y &= ~0xF; break;
01413     case TRACK_RIGHT: x &= ~0xF; y |=  0xF; break;
01414     default: break;
01415   }
01416   return GetSlopeZ(x, y);
01417 }
01418 
01419 static void DrawSingleSignal(TileIndex tile, Track track, byte condition, uint image, uint pos)
01420 {
01421   bool side = (_opt.road_side != 0) && _patches.signal_side;
01422   static const Point SignalPositions[2][12] = {
01423     {      /* Signals on the left side */
01424     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01425       { 8,  5}, {14,  1}, { 1, 14}, { 9, 11}, { 1,  0}, { 3, 10},
01426     /*  LOWER     LOWER     X         X         Y         Y     */
01427       {11,  4}, {14, 14}, {11,  3}, { 4, 13}, { 3,  4}, {11, 13}
01428     }, {   /* Signals on the right side */
01429     /*  LEFT      LEFT      RIGHT     RIGHT     UPPER     UPPER */
01430       {14,  1}, {12, 10}, { 4,  6}, { 1, 14}, {10,  4}, { 0,  1},
01431     /*  LOWER     LOWER     X         X         Y         Y     */
01432       {14, 14}, { 5, 12}, {11, 13}, { 4,  3}, {13,  4}, { 3, 11}
01433     }
01434   };
01435 
01436   uint x = TileX(tile) * TILE_SIZE + SignalPositions[side][pos].x;
01437   uint y = TileY(tile) * TILE_SIZE + SignalPositions[side][pos].y;
01438 
01439   SpriteID sprite;
01440 
01441   SignalType type       = GetSignalType(tile, track);
01442   SignalVariant variant = GetSignalVariant(tile, track);
01443 
01444   if (type == SIGTYPE_NORMAL && variant == SIG_ELECTRIC) {
01445     /* Normal electric signals are picked from original sprites. */
01446     sprite = SPR_ORIGINAL_SIGNALS_BASE + image + condition;
01447   } else {
01448     /* All other signals are picked from add on sprites. */
01449     sprite = SPR_SIGNALS_BASE + (type - 1) * 16 + variant * 64 + image + condition;
01450   }
01451 
01452   AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
01453 }
01454 
01455 static uint32 _drawtile_track_palette;
01456 
01457 
01458 static void DrawTrackFence_NW(const TileInfo *ti)
01459 {
01460   SpriteID image = SPR_TRACK_FENCE_FLAT_X;
01461   if (ti->tileh != SLOPE_FLAT) image = (ti->tileh & SLOPE_S) ? SPR_TRACK_FENCE_SLOPE_SW : SPR_TRACK_FENCE_SLOPE_NE;
01462   AddSortableSpriteToDraw(image, _drawtile_track_palette,
01463     ti->x, ti->y + 1, 16, 1, 4, ti->z);
01464 }
01465 
01466 static void DrawTrackFence_SE(const TileInfo *ti)
01467 {
01468   SpriteID image = SPR_TRACK_FENCE_FLAT_X;
01469   if (ti->tileh != SLOPE_FLAT) image = (ti->tileh & SLOPE_S) ? SPR_TRACK_FENCE_SLOPE_SW : SPR_TRACK_FENCE_SLOPE_NE;
01470   AddSortableSpriteToDraw(image, _drawtile_track_palette,
01471     ti->x, ti->y + TILE_SIZE - 1, 16, 1, 4, ti->z);
01472 }
01473 
01474 static void DrawTrackFence_NW_SE(const TileInfo *ti)
01475 {
01476   DrawTrackFence_NW(ti);
01477   DrawTrackFence_SE(ti);
01478 }
01479 
01480 static void DrawTrackFence_NE(const TileInfo *ti)
01481 {
01482   SpriteID image = SPR_TRACK_FENCE_FLAT_Y;
01483   if (ti->tileh != SLOPE_FLAT) image = (ti->tileh & SLOPE_S) ? SPR_TRACK_FENCE_SLOPE_SE : SPR_TRACK_FENCE_SLOPE_NW;
01484   AddSortableSpriteToDraw(image, _drawtile_track_palette,
01485     ti->x + 1, ti->y, 1, 16, 4, ti->z);
01486 }
01487 
01488 static void DrawTrackFence_SW(const TileInfo *ti)
01489 {
01490   SpriteID image = SPR_TRACK_FENCE_FLAT_Y;
01491   if (ti->tileh != SLOPE_FLAT) image = (ti->tileh & SLOPE_S) ? SPR_TRACK_FENCE_SLOPE_SE : SPR_TRACK_FENCE_SLOPE_NW;
01492   AddSortableSpriteToDraw(image, _drawtile_track_palette,
01493     ti->x + TILE_SIZE - 1, ti->y, 1, 16, 4, ti->z);
01494 }
01495 
01496 static void DrawTrackFence_NE_SW(const TileInfo *ti)
01497 {
01498   DrawTrackFence_NE(ti);
01499   DrawTrackFence_SW(ti);
01500 }
01501 
01505 static void DrawTrackFence_NS_1(const TileInfo *ti)
01506 {
01507   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_W);
01508   AddSortableSpriteToDraw(SPR_TRACK_FENCE_FLAT_VERT, _drawtile_track_palette,
01509     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01510 }
01511 
01515 static void DrawTrackFence_NS_2(const TileInfo *ti)
01516 {
01517   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_E);
01518   AddSortableSpriteToDraw(SPR_TRACK_FENCE_FLAT_VERT, _drawtile_track_palette,
01519     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01520 }
01521 
01525 static void DrawTrackFence_WE_1(const TileInfo *ti)
01526 {
01527   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_N);
01528   AddSortableSpriteToDraw(SPR_TRACK_FENCE_FLAT_HORZ, _drawtile_track_palette,
01529     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01530 }
01531 
01535 static void DrawTrackFence_WE_2(const TileInfo *ti)
01536 {
01537   uint z = ti->z + GetSlopeZInCorner(RemoveHalftileSlope(ti->tileh), CORNER_S);
01538   AddSortableSpriteToDraw(SPR_TRACK_FENCE_FLAT_HORZ, _drawtile_track_palette,
01539     ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
01540 }
01541 
01542 
01543 static void DrawTrackDetails(const TileInfo* ti)
01544 {
01545   switch (GetRailGroundType(ti->tile)) {
01546     case RAIL_GROUND_FENCE_NW:     DrawTrackFence_NW(ti);    break;
01547     case RAIL_GROUND_FENCE_SE:     DrawTrackFence_SE(ti);    break;
01548     case RAIL_GROUND_FENCE_SENW:   DrawTrackFence_NW_SE(ti); break;
01549     case RAIL_GROUND_FENCE_NE:     DrawTrackFence_NE(ti);    break;
01550     case RAIL_GROUND_FENCE_SW:     DrawTrackFence_SW(ti);    break;
01551     case RAIL_GROUND_FENCE_NESW:   DrawTrackFence_NE_SW(ti); break;
01552     case RAIL_GROUND_FENCE_VERT1:  DrawTrackFence_NS_1(ti);  break;
01553     case RAIL_GROUND_FENCE_VERT2:  DrawTrackFence_NS_2(ti);  break;
01554     case RAIL_GROUND_FENCE_HORIZ1: DrawTrackFence_WE_1(ti);  break;
01555     case RAIL_GROUND_FENCE_HORIZ2: DrawTrackFence_WE_2(ti);  break;
01556     case RAIL_GROUND_WATER: {
01557       Corner track_corner;
01558       if (IsHalftileSlope(ti->tileh)) {
01559         /* Steep slope or one-corner-raised slope with halftile foundation */
01560         track_corner = GetHalftileSlopeCorner(ti->tileh);
01561       } else {
01562         /* Three-corner-raised slope */
01563         track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
01564       }
01565       switch (track_corner) {
01566         case CORNER_W: DrawTrackFence_NS_1(ti); break;
01567         case CORNER_S: DrawTrackFence_WE_2(ti); break;
01568         case CORNER_E: DrawTrackFence_NS_2(ti); break;
01569         case CORNER_N: DrawTrackFence_WE_1(ti); break;
01570         default: NOT_REACHED();
01571       }
01572       break;
01573     }
01574     default: break;
01575   }
01576 }
01577 
01578 
01584 static void DrawTrackBits(TileInfo* ti, TrackBits track)
01585 {
01586   /* SubSprite for drawing the track halftile of 'three-corners-raised'-sloped rail sprites. */
01587   static const int INF = 1000; // big number compared to tilesprite size
01588   static const SubSprite _halftile_sub_sprite[4] = {
01589     { -INF    , -INF  , 32 - 33, INF     }, // CORNER_W, clip 33 pixels from right
01590     { -INF    ,  0 + 7, INF    , INF     }, // CORNER_S, clip 7 pixels from top
01591     { -31 + 33, -INF  , INF    , INF     }, // CORNER_E, clip 33 pixels from left
01592     { -INF    , -INF  , INF    , 30 - 23 }  // CORNER_N, clip 23 pixels from bottom
01593   };
01594 
01595   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
01596   RailGroundType rgt = GetRailGroundType(ti->tile);
01597   Foundation f = GetRailFoundation(ti->tileh, track);
01598   Corner halftile_corner = CORNER_INVALID;
01599 
01600   if (IsNonContinuousFoundation(f)) {
01601     /* Save halftile corner */
01602     halftile_corner = (f == FOUNDATION_STEEP_BOTH ? GetHighestSlopeCorner(ti->tileh) : GetHalftileFoundationCorner(f));
01603     /* Draw lower part first */
01604     track &= ~CornerToTrackBits(halftile_corner);
01605     f = (f == FOUNDATION_STEEP_BOTH ? FOUNDATION_STEEP_LOWER : FOUNDATION_NONE);
01606   }
01607 
01608   DrawFoundation(ti, f);
01609   /* DrawFoundation modifies ti */
01610 
01611   SpriteID image;
01612   SpriteID pal = PAL_NONE;
01613   const SubSprite *sub = NULL;
01614   bool junction = false;
01615 
01616   /* Select the sprite to use. */
01617   if (track == 0) {
01618     /* Clear ground (only track on halftile foundation) */
01619     if (rgt == RAIL_GROUND_WATER) {
01620       if (IsSteepSlope(ti->tileh)) {
01621         DrawShoreTile(ti->tileh);
01622         image = 0;
01623       } else {
01624         image = SPR_FLAT_WATER_TILE;
01625       }
01626     } else {
01627       switch (rgt) {
01628         case RAIL_GROUND_BARREN:     image = SPR_FLAT_BARE_LAND;  break;
01629         case RAIL_GROUND_ICE_DESERT: image = SPR_FLAT_SNOWY_TILE; break;
01630         default:                     image = SPR_FLAT_GRASS_TILE; break;
01631       }
01632       image += _tileh_to_sprite[ti->tileh];
01633     }
01634   } else {
01635     if (ti->tileh != SLOPE_FLAT) {
01636       /* track on non-flat ground */
01637       image = _track_sloped_sprites[ti->tileh - 1] + rti->base_sprites.track_y;
01638     } else {
01639       /* track on flat ground */
01640       (image = rti->base_sprites.track_y, track == TRACK_BIT_Y) ||
01641       (image++,                           track == TRACK_BIT_X) ||
01642       (image++,                           track == TRACK_BIT_UPPER) ||
01643       (image++,                           track == TRACK_BIT_LOWER) ||
01644       (image++,                           track == TRACK_BIT_RIGHT) ||
01645       (image++,                           track == TRACK_BIT_LEFT) ||
01646       (image++,                           track == TRACK_BIT_CROSS) ||
01647 
01648       (image = rti->base_sprites.track_ns, track == TRACK_BIT_HORZ) ||
01649       (image++,                            track == TRACK_BIT_VERT) ||
01650 
01651       (junction = true, false) ||
01652       (image = rti->base_sprites.ground, (track & TRACK_BIT_3WAY_NE) == 0) ||
01653       (image++,                          (track & TRACK_BIT_3WAY_SW) == 0) ||
01654       (image++,                          (track & TRACK_BIT_3WAY_NW) == 0) ||
01655       (image++,                          (track & TRACK_BIT_3WAY_SE) == 0) ||
01656       (image++, true);
01657     }
01658 
01659     switch (rgt) {
01660       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
01661       case RAIL_GROUND_ICE_DESERT: image += rti->snow_offset;  break;
01662       case RAIL_GROUND_WATER: {
01663         /* three-corner-raised slope */
01664         DrawShoreTile(ti->tileh);
01665         Corner track_corner = OppositeCorner(GetHighestSlopeCorner(ComplementSlope(ti->tileh)));
01666         sub = &(_halftile_sub_sprite[track_corner]);
01667         break;
01668       }
01669       default: break;
01670     }
01671   }
01672 
01673   if (image != 0) DrawGroundSprite(image, pal, sub);
01674 
01675   /* Draw track pieces individually for junction tiles */
01676   if (junction) {
01677     if (track & TRACK_BIT_X)     DrawGroundSprite(rti->base_sprites.single_y, PAL_NONE);
01678     if (track & TRACK_BIT_Y)     DrawGroundSprite(rti->base_sprites.single_x, PAL_NONE);
01679     if (track & TRACK_BIT_UPPER) DrawGroundSprite(rti->base_sprites.single_n, PAL_NONE);
01680     if (track & TRACK_BIT_LOWER) DrawGroundSprite(rti->base_sprites.single_s, PAL_NONE);
01681     if (track & TRACK_BIT_LEFT)  DrawGroundSprite(rti->base_sprites.single_w, PAL_NONE);
01682     if (track & TRACK_BIT_RIGHT) DrawGroundSprite(rti->base_sprites.single_e, PAL_NONE);
01683   }
01684 
01685   if (IsValidCorner(halftile_corner)) {
01686     DrawFoundation(ti, HalftileFoundation(halftile_corner));
01687 
01688     /* Draw higher halftile-overlay: Use the sloped sprites with three corners raised. They probably best fit the lightning. */
01689     Slope fake_slope = SlopeWithThreeCornersRaised(OppositeCorner(halftile_corner));
01690     image = _track_sloped_sprites[fake_slope - 1] + rti->base_sprites.track_y;
01691     pal = PAL_NONE;
01692     switch (rgt) {
01693       case RAIL_GROUND_BARREN:     pal = PALETTE_TO_BARE_LAND; break;
01694       case RAIL_GROUND_ICE_DESERT:
01695       case RAIL_GROUND_HALF_SNOW:  image += rti->snow_offset;  break; // higher part has snow in this case too
01696       default: break;
01697     }
01698     DrawGroundSprite(image, pal, &(_halftile_sub_sprite[halftile_corner]));
01699   }
01700 }
01701 
01707 enum {
01708   SIGNAL_TO_SOUTHWEST =  0,
01709   SIGNAL_TO_NORTHEAST =  2,
01710   SIGNAL_TO_SOUTHEAST =  4,
01711   SIGNAL_TO_NORTHWEST =  6,
01712   SIGNAL_TO_EAST      =  8,
01713   SIGNAL_TO_WEST      = 10,
01714   SIGNAL_TO_SOUTH     = 12,
01715   SIGNAL_TO_NORTH     = 14,
01716 };
01717 
01718 static void DrawSignals(TileIndex tile, TrackBits rails)
01719 {
01720 #define MAYBE_DRAW_SIGNAL(x,y,z,t) if (IsSignalPresent(tile, x)) DrawSingleSignal(tile, t, GetSingleSignalState(tile, x), y, z)
01721 
01722   if (!(rails & TRACK_BIT_Y)) {
01723     if (!(rails & TRACK_BIT_X)) {
01724       if (rails & TRACK_BIT_LEFT) {
01725         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTH, 0, TRACK_LEFT);
01726         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTH, 1, TRACK_LEFT);
01727       }
01728       if (rails & TRACK_BIT_RIGHT) {
01729         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_NORTH, 2, TRACK_RIGHT);
01730         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_SOUTH, 3, TRACK_RIGHT);
01731       }
01732       if (rails & TRACK_BIT_UPPER) {
01733         MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_WEST, 4, TRACK_UPPER);
01734         MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_EAST, 5, TRACK_UPPER);
01735       }
01736       if (rails & TRACK_BIT_LOWER) {
01737         MAYBE_DRAW_SIGNAL(1, SIGNAL_TO_WEST, 6, TRACK_LOWER);
01738         MAYBE_DRAW_SIGNAL(0, SIGNAL_TO_EAST, 7, TRACK_LOWER);
01739       }
01740     } else {
01741       MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHWEST, 8, TRACK_X);
01742       MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHEAST, 9, TRACK_X);
01743     }
01744   } else {
01745     MAYBE_DRAW_SIGNAL(3, SIGNAL_TO_SOUTHEAST, 10, TRACK_Y);
01746     MAYBE_DRAW_SIGNAL(2, SIGNAL_TO_NORTHWEST, 11, TRACK_Y);
01747   }
01748 }
01749 
01750 static void DrawTile_Track(TileInfo *ti)
01751 {
01752   const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
01753   SpriteID image;
01754 
01755   _drawtile_track_palette = PLAYER_SPRITE_COLOR(GetTileOwner(ti->tile));
01756 
01757   if (IsPlainRailTile(ti->tile)) {
01758     TrackBits rails = GetTrackBits(ti->tile);
01759 
01760     DrawTrackBits(ti, rails);
01761 
01762     if (HasBit(_display_opt, DO_FULL_DETAIL)) DrawTrackDetails(ti);
01763 
01764     if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
01765 
01766     if (HasSignals(ti->tile)) DrawSignals(ti->tile, rails);
01767   } else {
01768     /* draw depot/waypoint */
01769     const DrawTileSprites* dts;
01770     const DrawTileSeqStruct* dtss;
01771     uint32 relocation;
01772 
01773     if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);
01774 
01775     if (IsRailDepot(ti->tile)) {
01776       dts = &_depot_gfx_table[GetRailDepotDirection(ti->tile)];
01777 
01778       relocation = rti->total_offset;
01779 
01780       image = dts->ground.sprite;
01781       if (image != SPR_FLAT_GRASS_TILE) image += rti->total_offset;
01782 
01783       /* adjust ground tile for desert
01784        * don't adjust for snow, because snow in depots looks weird */
01785       if (IsSnowRailGround(ti->tile) && _opt.landscape == LT_TROPIC) {
01786         if (image != SPR_FLAT_GRASS_TILE) {
01787           image += rti->snow_offset; // tile with tracks
01788         } else {
01789           image = SPR_FLAT_SNOWY_TILE; // flat ground
01790         }
01791       }
01792     } else {
01793       /* look for customization */
01794       byte stat_id = GetWaypointByTile(ti->tile)->stat_id;
01795       const StationSpec *statspec = GetCustomStationSpec(STAT_CLASS_WAYP, stat_id);
01796 
01797       if (statspec != NULL) {
01798         /* emulate station tile - open with building */
01799         const Station* st = ComposeWaypointStation(ti->tile);
01800         uint gfx = 2;
01801 
01802         if (HasBit(statspec->callbackmask, CBM_STATION_SPRITE_LAYOUT)) {
01803           uint16 callback = GetStationCallback(CBID_STATION_SPRITE_LAYOUT, 0, 0, statspec, st, ti->tile);
01804           if (callback != CALLBACK_FAILED) gfx = callback;
01805         }
01806 
01807         if (statspec->renderdata == NULL) {
01808           dts = GetStationTileLayout(STATION_RAIL, gfx);
01809         } else {
01810           dts = &statspec->renderdata[(gfx < statspec->tiles ? gfx : 0) + GetWaypointAxis(ti->tile)];
01811         }
01812 
01813         if (dts != NULL && dts->seq != NULL) {
01814           relocation = GetCustomStationRelocation(statspec, st, ti->tile);
01815 
01816           image = dts->ground.sprite;
01817           if (HasBit(image, SPRITE_MODIFIER_USE_OFFSET)) {
01818             image += GetCustomStationGroundRelocation(statspec, st, ti->tile);
01819             image += rti->custom_ground_offset;
01820           } else {
01821             image += rti->total_offset;
01822           }
01823         } else {
01824           goto default_waypoint;
01825         }
01826       } else {
01827 default_waypoint:
01828         /* There is no custom layout, fall back to the default graphics */
01829         dts = &_waypoint_gfx_table[GetWaypointAxis(ti->tile)];
01830         relocation = 0;
01831         image = dts->ground.sprite + rti->total_offset;
01832         if (IsSnowRailGround(ti->tile)) image += rti->snow_offset;
01833       }
01834     }
01835 
01836     DrawGroundSprite(image, PAL_NONE);
01837 
01838     if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
01839 
01840     foreach_draw_tile_seq(dtss, dts->seq) {
01841       SpriteID image = dtss->image.sprite;
01842       SpriteID pal;
01843 
01844       /* Unlike stations, our default waypoint has no variation for
01845        * different railtype, so don't use the railtype offset if
01846        * no relocation is set */
01847       if (HasBit(image, SPRITE_MODIFIER_USE_OFFSET)) {
01848         image += rti->total_offset;
01849       } else {
01850         image += relocation;
01851       }
01852 
01853       if (!(!HasBit(image, SPRITE_MODIFIER_OPAQUE) && IsTransparencySet(TO_BUILDINGS)) && HasBit(image, PALETTE_MODIFIER_COLOR)) {
01854         pal = _drawtile_track_palette;
01855       } else {
01856         pal = dtss->image.pal;
01857       }
01858 
01859       if ((byte)dtss->delta_z != 0x80) {
01860         AddSortableSpriteToDraw(
01861           image, pal,
01862           ti->x + dtss->delta_x, ti->y + dtss->delta_y,
01863           dtss->size_x, dtss->size_y,
01864           dtss->size_z, ti->z + dtss->delta_z,
01865           !HasBit(image, SPRITE_MODIFIER_OPAQUE) && IsTransparencySet(TO_BUILDINGS)
01866         );
01867       } else {
01868         AddChildSpriteScreen(image, pal, dtss->delta_x, dtss->delta_y);
01869       }
01870     }
01871   }
01872   DrawBridgeMiddle(ti);
01873 }
01874 
01875 
01876 static void DrawTileSequence(int x, int y, SpriteID ground, const DrawTileSeqStruct* dtss, uint32 offset)
01877 {
01878   SpriteID palette = PLAYER_SPRITE_COLOR(_local_player);
01879 
01880   DrawSprite(ground, PAL_NONE, x, y);
01881   for (; dtss->image.sprite != 0; dtss++) {
01882     Point pt = RemapCoords(dtss->delta_x, dtss->delta_y, dtss->delta_z);
01883     SpriteID image = dtss->image.sprite + offset;
01884 
01885     DrawSprite(image, HasBit(image, PALETTE_MODIFIER_COLOR) ? palette : PAL_NONE, x + pt.x, y + pt.y);
01886   }
01887 }
01888 
01889 void DrawTrainDepotSprite(int x, int y, int dir, RailType railtype)
01890 {
01891   const DrawTileSprites* dts = &_depot_gfx_table[dir];
01892   SpriteID image = dts->ground.sprite;
01893   uint32 offset = GetRailTypeInfo(railtype)->total_offset;
01894 
01895   if (image != SPR_FLAT_GRASS_TILE) image += offset;
01896   DrawTileSequence(x + 33, y + 17, image, dts->seq, offset);
01897 }
01898 
01899 void DrawDefaultWaypointSprite(int x, int y, RailType railtype)
01900 {
01901   uint32 offset = GetRailTypeInfo(railtype)->total_offset;
01902   const DrawTileSprites* dts = &_waypoint_gfx_table[AXIS_X];
01903 
01904   DrawTileSequence(x, y, dts->ground.sprite + offset, dts->seq, 0);
01905 }
01906 
01907 static uint GetSlopeZ_Track(TileIndex tile, uint x, uint y)
01908 {
01909   uint z;
01910   Slope tileh = GetTileSlope(tile, &z);
01911 
01912   if (tileh == SLOPE_FLAT) return z;
01913   if (IsPlainRailTile(tile)) {
01914     z += ApplyFoundationToSlope(GetRailFoundation(tileh, GetTrackBits(tile)), &tileh);
01915     return z + GetPartialZ(x & 0xF, y & 0xF, tileh);
01916   } else {
01917     return z + TILE_HEIGHT;
01918   }
01919 }
01920 
01921 static Foundation GetFoundation_Track(TileIndex tile, Slope tileh)
01922 {
01923   return IsPlainRailTile(tile) ? GetRailFoundation(tileh, GetTrackBits(tile)) : FlatteningFoundation(tileh);
01924 }
01925 
01926 static void GetAcceptedCargo_Track(TileIndex tile, AcceptedCargo ac)
01927 {
01928   /* not used */
01929 }
01930 
01931 static void AnimateTile_Track(TileIndex tile)
01932 {
01933   /* not used */
01934 }
01935 
01936 static void TileLoop_Track(TileIndex tile)
01937 {
01938   RailGroundType old_ground = GetRailGroundType(tile);
01939   RailGroundType new_ground;
01940 
01941   if (old_ground == RAIL_GROUND_WATER) {
01942     TileLoop_Water(tile);
01943     return;
01944   }
01945 
01946   switch (_opt.landscape) {
01947     case LT_ARCTIC: {
01948       uint z;
01949       Slope slope = GetTileSlope(tile, &z);
01950       bool half = false;
01951 
01952       /* for non-flat track, use lower part of track
01953        * in other cases, use the highest part with track */
01954       if (IsPlainRailTile(tile)) {
01955         TrackBits track = GetTrackBits(tile);
01956         Foundation f = GetRailFoundation(slope, track);
01957 
01958         switch (f) {
01959           case FOUNDATION_NONE:
01960             /* no foundation - is the track on the upper side of three corners raised tile? */
01961             if (IsSlopeWithThreeCornersRaised(slope)) z += TILE_HEIGHT;
01962             break;
01963 
01964           case FOUNDATION_INCLINED_X:
01965           case FOUNDATION_INCLINED_Y:
01966             /* sloped track - is it on a steep slope? */
01967             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
01968             break;
01969 
01970           case FOUNDATION_STEEP_LOWER:
01971             /* only lower part of steep slope */
01972             z += TILE_HEIGHT;
01973             break;
01974 
01975           default:
01976             /* if it is a steep slope, then there is a track on higher part */
01977             if (IsSteepSlope(slope)) z += TILE_HEIGHT;
01978             z += TILE_HEIGHT;
01979             break;
01980         }
01981 
01982         half = IsInsideMM(f, FOUNDATION_STEEP_BOTH, FOUNDATION_HALFTILE_N + 1);
01983       } else {
01984         /* is the depot on a non-flat tile? */
01985         if (slope != SLOPE_FLAT) z += TILE_HEIGHT;
01986       }
01987 
01988       /* 'z' is now the lowest part of the highest track bit -
01989        * for sloped track, it is 'z' of lower part
01990        * for two track bits, it is 'z' of higher track bit
01991        * For non-continuous foundations (and STEEP_BOTH), 'half' is set */
01992       if (z > GetSnowLine()) {
01993         if (half && z - GetSnowLine() == TILE_HEIGHT) {
01994           /* track on non-continuous foundation, lower part is not under snow */
01995           new_ground = RAIL_GROUND_HALF_SNOW;
01996         } else {
01997           new_ground = RAIL_GROUND_ICE_DESERT;
01998         }
01999         goto set_ground;
02000       }
02001       break;
02002       }
02003 
02004     case LT_TROPIC:
02005       if (GetTropicZone(tile) == TROPICZONE_DESERT) {
02006         new_ground = RAIL_GROUND_ICE_DESERT;
02007         goto set_ground;
02008       }
02009       break;
02010   }
02011 
02012   if (!IsPlainRailTile(tile)) return;
02013 
02014   new_ground = RAIL_GROUND_GRASS;
02015 
02016   if (old_ground != RAIL_GROUND_BARREN) { // wait until bottom is green
02017     /* determine direction of fence */
02018     TrackBits rail = GetTrackBits(tile);
02019 
02020     switch (rail) {
02021       case TRACK_BIT_UPPER: new_ground = RAIL_GROUND_FENCE_HORIZ1; break;
02022       case TRACK_BIT_LOWER: new_ground = RAIL_GROUND_FENCE_HORIZ2; break;
02023       case TRACK_BIT_LEFT:  new_ground = RAIL_GROUND_FENCE_VERT1;  break;
02024       case TRACK_BIT_RIGHT: new_ground = RAIL_GROUND_FENCE_VERT2;  break;
02025 
02026       default: {
02027         PlayerID owner = GetTileOwner(tile);
02028 
02029         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_RIGHT) || (
02030               (rail & TRACK_BIT_3WAY_NW) == 0 &&
02031               (rail & TRACK_BIT_X)
02032             )) {
02033           TileIndex n = tile + TileDiffXY(0, -1);
02034           TrackBits nrail = GetTrackBits(n);
02035 
02036           if (!IsTileType(n, MP_RAILWAY) ||
02037               !IsTileOwner(n, owner) ||
02038               nrail == TRACK_BIT_UPPER ||
02039               nrail == TRACK_BIT_LEFT) {
02040             new_ground = RAIL_GROUND_FENCE_NW;
02041           }
02042         }
02043 
02044         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_LEFT) || (
02045               (rail & TRACK_BIT_3WAY_SE) == 0 &&
02046               (rail & TRACK_BIT_X)
02047             )) {
02048           TileIndex n = tile + TileDiffXY(0, 1);
02049           TrackBits nrail = GetTrackBits(n);
02050 
02051           if (!IsTileType(n, MP_RAILWAY) ||
02052               !IsTileOwner(n, owner) ||
02053               nrail == TRACK_BIT_LOWER ||
02054               nrail == TRACK_BIT_RIGHT) {
02055             new_ground = (new_ground == RAIL_GROUND_FENCE_NW) ?
02056               RAIL_GROUND_FENCE_SENW : RAIL_GROUND_FENCE_SE;
02057           }
02058         }
02059 
02060         if (rail == (TRACK_BIT_LOWER | TRACK_BIT_LEFT) || (
02061               (rail & TRACK_BIT_3WAY_NE) == 0 &&
02062               (rail & TRACK_BIT_Y)
02063             )) {
02064           TileIndex n = tile + TileDiffXY(-1, 0);
02065           TrackBits nrail = GetTrackBits(n);
02066 
02067           if (!IsTileType(n, MP_RAILWAY) ||
02068               !IsTileOwner(n, owner) ||
02069               nrail == TRACK_BIT_UPPER ||
02070               nrail == TRACK_BIT_RIGHT) {
02071             new_ground = RAIL_GROUND_FENCE_NE;
02072           }
02073         }
02074 
02075         if (rail == (TRACK_BIT_UPPER | TRACK_BIT_RIGHT) || (
02076               (rail & TRACK_BIT_3WAY_SW) == 0 &&
02077               (rail & TRACK_BIT_Y)
02078             )) {
02079           TileIndex n = tile + TileDiffXY(1, 0);
02080           TrackBits nrail = GetTrackBits(n);
02081 
02082           if (!IsTileType(n, MP_RAILWAY) ||
02083               !IsTileOwner(n, owner) ||
02084               nrail == TRACK_BIT_LOWER ||
02085               nrail == TRACK_BIT_LEFT) {
02086             new_ground = (new_ground == RAIL_GROUND_FENCE_NE) ?
02087               RAIL_GROUND_FENCE_NESW : RAIL_GROUND_FENCE_SW;
02088           }
02089         }
02090         break;
02091       }
02092     }
02093   }
02094 
02095 set_ground:
02096   if (old_ground != new_ground) {
02097     SetRailGroundType(tile, new_ground);
02098     MarkTileDirtyByTile(tile);
02099   }
02100 }
02101 
02102 
02103 static TrackStatus GetTileTrackStatus_Track(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
02104 {
02105   /* Case of half tile slope with water. */
02106   if (mode == TRANSPORT_WATER && IsPlainRailTile(tile) && GetRailGroundType(tile) == RAIL_GROUND_WATER) {
02107     TrackBits tb = GetTrackBits(tile);
02108     switch (tb) {
02109       default: NOT_REACHED();
02110       case TRACK_BIT_UPPER: tb = TRACK_BIT_LOWER; break;
02111       case TRACK_BIT_LOWER: tb = TRACK_BIT_UPPER; break;
02112       case TRACK_BIT_LEFT:  tb = TRACK_BIT_RIGHT; break;
02113       case TRACK_BIT_RIGHT: tb = TRACK_BIT_LEFT;  break;
02114     }
02115     return CombineTrackStatus(TrackBitsToTrackdirBits(tb), TRACKDIR_BIT_NONE);
02116   }
02117 
02118   if (mode != TRANSPORT_RAIL) return 0;
02119 
02120   TrackBits trackbits = TRACK_BIT_NONE;
02121   TrackdirBits red_signals = TRACKDIR_BIT_NONE;
02122 
02123   switch (GetRailTileType(tile)) {
02124     default: NOT_REACHED();
02125     case RAIL_TILE_NORMAL:
02126       trackbits = GetTrackBits(tile);
02127       break;
02128 
02129     case RAIL_TILE_SIGNALS: {
02130       trackbits = GetTrackBits(tile);
02131       byte a = GetPresentSignals(tile);
02132       uint b = GetSignalStates(tile);
02133 
02134       b &= a;
02135 
02136       /* When signals are not present (in neither
02137        * direction), we pretend them to be green. (So if
02138        * signals are only one way, the other way will
02139        * implicitely become `red' */
02140       if ((a & 0xC) == 0) b |= 0xC;
02141       if ((a & 0x3) == 0) b |= 0x3;
02142 
02143       if ((b & 0x8) == 0) red_signals |= (TRACKDIR_BIT_LEFT_N | TRACKDIR_BIT_X_NE | TRACKDIR_BIT_Y_SE | TRACKDIR_BIT_UPPER_E);
02144       if ((b & 0x4) == 0) red_signals |= (TRACKDIR_BIT_LEFT_S | TRACKDIR_BIT_X_SW | TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_UPPER_W);
02145       if ((b & 0x2) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_N | TRACKDIR_BIT_LOWER_E);
02146       if ((b & 0x1) == 0) red_signals |= (TRACKDIR_BIT_RIGHT_S | TRACKDIR_BIT_LOWER_W);
02147 
02148       break;
02149     }
02150 
02151     case RAIL_TILE_DEPOT: {
02152       DiagDirection dir = GetRailDepotDirection(tile);
02153 
02154       if (side != INVALID_DIAGDIR && side != dir) break;
02155 
02156       trackbits = AxisToTrackBits(DiagDirToAxis(dir));
02157       break;
02158     }
02159 
02160     case RAIL_TILE_WAYPOINT:
02161       trackbits = GetRailWaypointBits(tile);
02162       break;
02163   }
02164 
02165   return CombineTrackStatus(TrackBitsToTrackdirBits(trackbits), red_signals);
02166 }
02167 
02168 static void ClickTile_Track(TileIndex tile)
02169 {
02170   switch (GetRailTileType(tile)) {
02171     case RAIL_TILE_DEPOT:    ShowDepotWindow(tile, VEH_TRAIN);                  break;
02172     case RAIL_TILE_WAYPOINT: ShowRenameWaypointWindow(GetWaypointByTile(tile)); break;
02173     default: break;
02174   }
02175 }
02176 
02177 static void GetTileDesc_Track(TileIndex tile, TileDesc *td)
02178 {
02179   td->owner = GetTileOwner(tile);
02180   switch (GetRailTileType(tile)) {
02181     case RAIL_TILE_NORMAL:
02182       td->str = STR_1021_RAILROAD_TRACK;
02183       break;
02184 
02185     case RAIL_TILE_SIGNALS: {
02186       const StringID signal_type[4][4] = {
02187         {
02188           STR_RAILROAD_TRACK_WITH_NORMAL_SIGNALS,
02189           STR_RAILROAD_TRACK_WITH_NORMAL_PRESIGNALS,
02190           STR_RAILROAD_TRACK_WITH_NORMAL_EXITSIGNALS,
02191           STR_RAILROAD_TRACK_WITH_NORMAL_COMBOSIGNALS
02192         },
02193         {
02194           STR_RAILROAD_TRACK_WITH_NORMAL_PRESIGNALS,
02195           STR_RAILROAD_TRACK_WITH_PRESIGNALS,
02196           STR_RAILROAD_TRACK_WITH_PRE_EXITSIGNALS,
02197           STR_RAILROAD_TRACK_WITH_PRE_COMBOSIGNALS
02198         },
02199         {
02200           STR_RAILROAD_TRACK_WITH_NORMAL_EXITSIGNALS,
02201           STR_RAILROAD_TRACK_WITH_PRE_EXITSIGNALS,
02202           STR_RAILROAD_TRACK_WITH_EXITSIGNALS,
02203           STR_RAILROAD_TRACK_WITH_EXIT_COMBOSIGNALS
02204         },
02205         {
02206           STR_RAILROAD_TRACK_WITH_NORMAL_COMBOSIGNALS,
02207           STR_RAILROAD_TRACK_WITH_PRE_COMBOSIGNALS,
02208           STR_RAILROAD_TRACK_WITH_EXIT_COMBOSIGNALS,
02209           STR_RAILROAD_TRACK_WITH_COMBOSIGNALS
02210         }
02211       };
02212 
02213       td->str = signal_type[GetSignalType(tile, TRACK_UPPER)][GetSignalType(tile, TRACK_LOWER)];
02214       break;
02215     }
02216 
02217     case RAIL_TILE_DEPOT:
02218       td->str = STR_1023_RAILROAD_TRAIN_DEPOT;
02219       break;
02220 
02221     case RAIL_TILE_WAYPOINT:
02222     default:
02223       td->str = STR_LANDINFO_WAYPOINT;
02224       break;
02225   }
02226 }
02227 
02228 static void ChangeTileOwner_Track(TileIndex tile, PlayerID old_player, PlayerID new_player)
02229 {
02230   if (!IsTileOwner(tile, old_player)) return;
02231 
02232   if (new_player != PLAYER_SPECTATOR) {
02233     SetTileOwner(tile, new_player);
02234   } else {
02235     DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR);
02236   }
02237 }
02238 
02239 static const byte _fractcoords_behind[4] = { 0x8F, 0x8, 0x80, 0xF8 };
02240 static const byte _fractcoords_enter[4] = { 0x8A, 0x48, 0x84, 0xA8 };
02241 static const signed char _deltacoord_leaveoffset[8] = {
02242   -1,  0,  1,  0, /* x */
02243    0,  1,  0, -1  /* y */
02244 };
02245 
02246 
02252 int TicksToLeaveDepot(const Vehicle *v)
02253 {
02254   DiagDirection dir = GetRailDepotDirection(v->tile);
02255   int length = v->u.rail.cached_veh_length;
02256 
02257   switch (dir) {
02258     case DIAGDIR_NE: return  ((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) - (length + 1)));
02259     case DIAGDIR_SE: return -((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   + (length + 1)));
02260     case DIAGDIR_SW: return -((int)(v->x_pos & 0x0F) - ((_fractcoords_enter[dir] & 0x0F) + (length + 1)));
02261     default:
02262     case DIAGDIR_NW: return  ((int)(v->y_pos & 0x0F) - ((_fractcoords_enter[dir] >> 4)   - (length + 1)));
02263   }
02264 
02265   return 0; // make compilers happy
02266 }
02267 
02268 
02269 static VehicleEnterTileStatus VehicleEnter_Track(Vehicle *v, TileIndex tile, int x, int y)
02270 {
02271   byte fract_coord;
02272   byte fract_coord_leave;
02273   DiagDirection dir;
02274   int length;
02275 
02276   /* this routine applies only to trains in depot tiles */
02277   if (v->type != VEH_TRAIN || !IsTileDepotType(tile, TRANSPORT_RAIL)) return VETSB_CONTINUE;
02278 
02279   /* depot direction */
02280   dir = GetRailDepotDirection(tile);
02281 
02282   /* calculate the point where the following wagon should be activated */
02283   /* this depends on the length of the current vehicle */
02284   length = v->u.rail.cached_veh_length;
02285 
02286   fract_coord_leave =
02287     ((_fractcoords_enter[dir] & 0x0F) + // x
02288       (length + 1) * _deltacoord_leaveoffset[dir]) +
02289     (((_fractcoords_enter[dir] >> 4) +  // y
02290       ((length + 1) * _deltacoord_leaveoffset[dir+4])) << 4);
02291 
02292   fract_coord = (x & 0xF) + ((y & 0xF) << 4);
02293 
02294   if (_fractcoords_behind[dir] == fract_coord) {
02295     /* make sure a train is not entering the tile from behind */
02296     return VETSB_CANNOT_ENTER;
02297   } else if (_fractcoords_enter[dir] == fract_coord) {
02298     if (DiagDirToDir(ReverseDiagDir(dir)) == v->direction) {
02299       /* enter the depot */
02300       v->u.rail.track = TRACK_BIT_DEPOT,
02301       v->vehstatus |= VS_HIDDEN; /* hide it */
02302       v->direction = ReverseDir(v->direction);
02303       if (v->Next() == NULL) VehicleEnterDepot(v);
02304       v->tile = tile;
02305 
02306       InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02307       return VETSB_ENTERED_WORMHOLE;
02308     }
02309   } else if (fract_coord_leave == fract_coord) {
02310     if (DiagDirToDir(dir) == v->direction) {
02311       /* leave the depot? */
02312       if ((v = v->Next()) != NULL) {
02313         v->vehstatus &= ~VS_HIDDEN;
02314         v->u.rail.track = (DiagDirToAxis(dir) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y);
02315       }
02316     }
02317   }
02318 
02319   return VETSB_CONTINUE;
02320 }
02321 
02333 static CommandCost TestAutoslopeOnRailTile(TileIndex tile, uint flags, uint z_old, Slope tileh_old, uint z_new, Slope tileh_new, TrackBits rail_bits)
02334 {
02335   if (!_patches.build_on_slopes || !AutoslopeEnabled()) return CMD_ERROR;
02336 
02337   /* Is the slope-rail_bits combination valid in general? I.e. is it save to call GetRailFoundation() ? */
02338   if (CmdFailed(CheckRailSlope(tileh_new, rail_bits, TRACK_BIT_NONE, tile))) return CMD_ERROR;
02339 
02340   /* Get the slopes on top of the foundations */
02341   z_old += ApplyFoundationToSlope(GetRailFoundation(tileh_old, rail_bits), &tileh_old);
02342   z_new += ApplyFoundationToSlope(GetRailFoundation(tileh_new, rail_bits), &tileh_new);
02343 
02344   Corner track_corner;
02345   switch (rail_bits) {
02346     case TRACK_BIT_LEFT:  track_corner = CORNER_W; break;
02347     case TRACK_BIT_LOWER: track_corner = CORNER_S; break;
02348     case TRACK_BIT_RIGHT: track_corner = CORNER_E; break;
02349     case TRACK_BIT_UPPER: track_corner = CORNER_N; break;
02350 
02351     /* Surface slope must not be changed */
02352     default: return (((z_old != z_new) || (tileh_old != tileh_new)) ? CMD_ERROR : CommandCost(EXPENSES_CONSTRUCTION, _price.terraform));
02353   }
02354 
02355   /* The height of the track_corner must not be changed. The rest ensures GetRailFoundation() already. */
02356   z_old += GetSlopeZInCorner(RemoveHalftileSlope(tileh_old), track_corner);
02357   z_new += GetSlopeZInCorner(RemoveHalftileSlope(tileh_new), track_corner);
02358   if (z_old != z_new) return CMD_ERROR;
02359 
02360   CommandCost cost = CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);
02361   /* Make the ground dirty, if surface slope has changed */
02362   if (tileh_old != tileh_new) {
02363     /* If there is flat water on the lower halftile add the cost for clearing it */
02364     if (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old)) cost.AddCost(_price.clear_water);
02365     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
02366   }
02367   return  cost;
02368 }
02369 
02370 static CommandCost TerraformTile_Track(TileIndex tile, uint32 flags, uint z_new, Slope tileh_new)
02371 {
02372   uint z_old;
02373   Slope tileh_old = GetTileSlope(tile, &z_old);
02374   if (IsPlainRailTile(tile)) {
02375     TrackBits rail_bits = GetTrackBits(tile);
02376     /* Is there flat water on the lower halftile, that must be cleared expensively? */
02377     bool was_water = (GetRailGroundType(tile) == RAIL_GROUND_WATER && IsSlopeWithOneCornerRaised(tileh_old));
02378 
02379     _error_message = STR_1008_MUST_REMOVE_RAILROAD_TRACK;
02380 
02381     /* First test autoslope. However if it succeeds we still have to test the rest, because non-autoslope terraforming is cheaper. */
02382     CommandCost autoslope_result = TestAutoslopeOnRailTile(tile, flags, z_old, tileh_old, z_new, tileh_new, rail_bits);
02383 
02384     /* When there is only a single horizontal/vertical track, one corner can be terraformed. */
02385     Corner allowed_corner;
02386     switch (rail_bits) {
02387       case TRACK_BIT_RIGHT: allowed_corner = CORNER_W; break;
02388       case TRACK_BIT_UPPER: allowed_corner = CORNER_S; break;
02389       case TRACK_BIT_LEFT:  allowed_corner = CORNER_E; break;
02390       case TRACK_BIT_LOWER: allowed_corner = CORNER_N; break;
02391       default: return autoslope_result;
02392     }
02393 
02394     Foundation f_old = GetRailFoundation(tileh_old, rail_bits);
02395 
02396     /* Do not allow terraforming if allowed_corner is part of anti-zig-zag foundations */
02397     if (tileh_old != SLOPE_NS && tileh_old != SLOPE_EW && IsSpecialRailFoundation(f_old)) return autoslope_result;
02398 
02399     /* Everything is valid, which only changes allowed_corner */
02400     for (Corner corner = (Corner)0; corner < CORNER_END; corner = (Corner)(corner + 1)) {
02401       if (allowed_corner == corner) continue;
02402       if (z_old + GetSlopeZInCorner(tileh_old, corner) != z_new + GetSlopeZInCorner(tileh_new, corner)) return autoslope_result;
02403     }
02404 
02405     /* Make the ground dirty */
02406     if ((flags & DC_EXEC) != 0) SetRailGroundType(tile, RAIL_GROUND_BARREN);
02407 
02408     /* allow terraforming */
02409     return CommandCost(EXPENSES_CONSTRUCTION, was_water ? _price.clear_water : (Money)0);
02410   } else {
02411     if (_patches.build_on_slopes && AutoslopeEnabled()) {
02412       switch (GetRailTileType(tile)) {
02413         case RAIL_TILE_WAYPOINT: {
02414           CommandCost cost = TestAutoslopeOnRailTile(tile, flags, z_old, tileh_old, z_new, tileh_new, GetRailWaypointBits(tile));
02415           if (!CmdFailed(cost)) return cost; // allow autoslope
02416           break;
02417         }
02418 
02419         case RAIL_TILE_DEPOT:
02420           if (AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRailDepotDirection(tile))) return CommandCost(EXPENSES_CONSTRUCTION, _price.terraform);
02421           break;
02422 
02423         default: NOT_REACHED();
02424       }
02425     }
02426   }
02427   return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
02428 }
02429 
02430 
02431 extern const TileTypeProcs _tile_type_rail_procs = {
02432   DrawTile_Track,           /* draw_tile_proc */
02433   GetSlopeZ_Track,          /* get_slope_z_proc */
02434   ClearTile_Track,          /* clear_tile_proc */
02435   GetAcceptedCargo_Track,   /* get_accepted_cargo_proc */
02436   GetTileDesc_Track,        /* get_tile_desc_proc */
02437   GetTileTrackStatus_Track, /* get_tile_track_status_proc */
02438   ClickTile_Track,          /* click_tile_proc */
02439   AnimateTile_Track,        /* animate_tile_proc */
02440   TileLoop_Track,           /* tile_loop_clear */
02441   ChangeTileOwner_Track,    /* change_tile_owner_clear */
02442   NULL,                     /* get_produced_cargo_proc */
02443   VehicleEnter_Track,       /* vehicle_enter_tile_proc */
02444   GetFoundation_Track,      /* get_foundation_proc */
02445   TerraformTile_Track,      /* terraform_tile_proc */
02446 };

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