# newgrf_house.cpp

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    00001 /* $Id: newgrf_house.cpp 19855 2010-05-18 21:30:56Z 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 "variables.h"
    00014 #include "debug.h"
    00015 #include "viewport_func.h"
    00016 #include "landscape.h"
    00017 #include "newgrf.h"
    00018 #include "newgrf_house.h"
    00019 #include "newgrf_spritegroup.h"
    00020 #include "newgrf_town.h"
    00021 #include "newgrf_sound.h"
    00022 #include "newgrf_commons.h"
    00023 #include "functions.h"
    00024 #include "company_func.h"
    00025 #include "animated_tile_func.h"
    00026 #include "company_base.h"
    00027 #include "town.h"
    00028 #include "core/random_func.hpp"
    00029 #include "sprite.h"
    00030
    00031 static BuildingCounts<uint32> _building_counts;
    00032 static HouseClassMapping _class_mapping[HOUSE_CLASS_MAX];
    00033
    00034 HouseOverrideManager _house_mngr(NEW_HOUSE_OFFSET, HOUSE_MAX, INVALID_HOUSE_ID);
    00035
    00036 HouseClassID AllocateHouseClassID(byte grf_class_id, uint32 grfid)
    00037 {
    00038   /* Start from 1 because 0 means that no class has been assigned. */
    00039   for (int i = 1; i != lengthof(_class_mapping); i++) {
    00040     HouseClassMapping *map = &_class_mapping[i];
    00041
    00042     if (map->class_id == grf_class_id && map->grfid == grfid) return (HouseClassID)i;
    00043
    00044     if (map->class_id == 0 && map->grfid == 0) {
    00045       map->class_id = grf_class_id;
    00046       map->grfid    = grfid;
    00047       return (HouseClassID)i;
    00048     }
    00049   }
    00050   return HOUSE_NO_CLASS;
    00051 }
    00052
    00053 void InitializeBuildingCounts()
    00054 {
    00055   memset(&_building_counts, 0, sizeof(_building_counts));
    00056 }
    00057
    00064 void IncreaseBuildingCount(Town *t, HouseID house_id)
    00065 {
    00066   HouseClassID class_id = HouseSpec::Get(house_id)->class_id;
    00067
    00068   if (!_loaded_newgrf_features.has_newhouses) return;
    00069
    00070   t->building_counts.id_count[house_id]++;
    00071   _building_counts.id_count[house_id]++;
    00072
    00073   if (class_id == HOUSE_NO_CLASS) return;
    00074
    00075   t->building_counts.class_count[class_id]++;
    00076   _building_counts.class_count[class_id]++;
    00077 }
    00078
    00085 void DecreaseBuildingCount(Town *t, HouseID house_id)
    00086 {
    00087   HouseClassID class_id = HouseSpec::Get(house_id)->class_id;
    00088
    00089   if (!_loaded_newgrf_features.has_newhouses) return;
    00090
    00091   if (t->building_counts.id_count[house_id] > 0) t->building_counts.id_count[house_id]--;
    00092   if (_building_counts.id_count[house_id] > 0)   _building_counts.id_count[house_id]--;
    00093
    00094   if (class_id == HOUSE_NO_CLASS) return;
    00095
    00096   if (t->building_counts.class_count[class_id] > 0) t->building_counts.class_count[class_id]--;
    00097   if (_building_counts.class_count[class_id] > 0)   _building_counts.class_count[class_id]--;
    00098 }
    00099
    00100 static uint32 HouseGetRandomBits(const ResolverObject *object)
    00101 {
    00102   /* Note: Towns build houses over houses. So during construction checks 'tile' may be a valid but unrelated house. */
    00103   TileIndex tile = object->u.house.tile;
    00104   assert(IsValidTile(tile) && (object->u.house.not_yet_constructed || IsTileType(tile, MP_HOUSE)));
    00105   return object->u.house.not_yet_constructed ? 0 : GetHouseRandomBits(tile);
    00106 }
    00107
    00108 static uint32 HouseGetTriggers(const ResolverObject *object)
    00109 {
    00110   /* Note: Towns build houses over houses. So during construction checks 'tile' may be a valid but unrelated house. */
    00111   TileIndex tile = object->u.house.tile;
    00112   assert(IsValidTile(tile) && (object->u.house.not_yet_constructed || IsTileType(tile, MP_HOUSE)));
    00113   return object->u.house.not_yet_constructed ? 0 : GetHouseTriggers(tile);
    00114 }
    00115
    00116 static void HouseSetTriggers(const ResolverObject *object, int triggers)
    00117 {
    00118   TileIndex tile = object->u.house.tile;
    00119   assert(!object->u.house.not_yet_constructed && IsValidTile(tile) && IsTileType(tile, MP_HOUSE));
    00120   SetHouseTriggers(tile, triggers);
    00121 }
    00122
    00123 static uint32 GetNumHouses(HouseID house_id, const Town *town)
    00124 {
    00125   uint8 map_id_count, town_id_count, map_class_count, town_class_count;
    00126   HouseClassID class_id = HouseSpec::Get(house_id)->class_id;
    00127
    00128   map_id_count     = ClampU(_building_counts.id_count[house_id], 0, 255);
    00129   map_class_count  = ClampU(_building_counts.class_count[class_id], 0, 255);
    00130   town_id_count    = ClampU(town->building_counts.id_count[house_id], 0, 255);
    00131   town_class_count = ClampU(town->building_counts.class_count[class_id], 0, 255);
    00132
    00133   return map_class_count << 24 | town_class_count << 16 | map_id_count << 8 | town_id_count;
    00134 }
    00135
    00136 uint32 GetNearbyTileInformation(byte parameter, TileIndex tile)
    00137 {
    00138   tile = GetNearbyTile(parameter, tile);
    00139   return GetNearbyTileInformation(tile);
    00140 }
    00141
    00143 typedef struct {
    00144   const HouseSpec *hs;
    00145   TileIndex north_tile;
    00146 } SearchNearbyHouseData;
    00147
    00153 static bool SearchNearbyHouseID(TileIndex tile, void *user_data)
    00154 {
    00155   if (IsTileType(tile, MP_HOUSE)) {
    00156     HouseID house = GetHouseType(tile); // tile been examined
    00157     const HouseSpec *hs = HouseSpec::Get(house);
    00158     if (hs->grffile != NULL) { // must be one from a grf file
    00159       SearchNearbyHouseData *nbhd = (SearchNearbyHouseData *)user_data;
    00160
    00161       TileIndex north_tile = tile + GetHouseNorthPart(house); // modifies 'house'!
    00162       if (north_tile == nbhd->north_tile) return false; // Always ignore origin house
    00163
    00164       return hs->local_id == nbhd->hs->local_id &&  // same local id as the one requested
    00165         hs->grffile->grfid == nbhd->hs->grffile->grfid;  // from the same grf
    00166     }
    00167   }
    00168   return false;
    00169 }
    00170
    00176 static bool SearchNearbyHouseClass(TileIndex tile, void *user_data)
    00177 {
    00178   if (IsTileType(tile, MP_HOUSE)) {
    00179     HouseID house = GetHouseType(tile); // tile been examined
    00180     const HouseSpec *hs = HouseSpec::Get(house);
    00181     if (hs->grffile != NULL) { // must be one from a grf file
    00182       SearchNearbyHouseData *nbhd = (SearchNearbyHouseData *)user_data;
    00183
    00184       TileIndex north_tile = tile + GetHouseNorthPart(house); // modifies 'house'!
    00185       if (north_tile == nbhd->north_tile) return false; // Always ignore origin house
    00186
    00187       return hs->class_id == nbhd->hs->class_id &&  // same classid as the one requested
    00188         hs->grffile->grfid == nbhd->hs->grffile->grfid;  // from the same grf
    00189     }
    00190   }
    00191   return false;
    00192 }
    00193
    00199 static bool SearchNearbyHouseGRFID(TileIndex tile, void *user_data)
    00200 {
    00201   if (IsTileType(tile, MP_HOUSE)) {
    00202     HouseID house = GetHouseType(tile); // tile been examined
    00203     const HouseSpec *hs = HouseSpec::Get(house);
    00204     if (hs->grffile != NULL) { // must be one from a grf file
    00205       SearchNearbyHouseData *nbhd = (SearchNearbyHouseData *)user_data;
    00206
    00207       TileIndex north_tile = tile + GetHouseNorthPart(house); // modifies 'house'!
    00208       if (north_tile == nbhd->north_tile) return false; // Always ignore origin house
    00209
    00210       return hs->grffile->grfid == nbhd->hs->grffile->grfid;  // from the same grf
    00211     }
    00212   }
    00213   return false;
    00214 }
    00215
    00225 static uint32 GetDistanceFromNearbyHouse(uint8 parameter, TileIndex tile, HouseID house)
    00226 {
    00227   static TestTileOnSearchProc * const search_procs[3] = {
    00228     SearchNearbyHouseID,
    00229     SearchNearbyHouseClass,
    00230     SearchNearbyHouseGRFID,
    00231   };
    00232   TileIndex found_tile = tile;
    00233   uint8 searchtype = GB(parameter, 6, 2);
    00234   uint8 searchradius = GB(parameter, 0, 6);
    00235   if (searchtype >= lengthof(search_procs)) return 0;  // do not run on ill-defined code
    00236   if (searchradius < 1) return 0; // do not use a too low radius
    00237
    00238   SearchNearbyHouseData nbhd;
    00239   nbhd.hs = HouseSpec::Get(house);
    00240   nbhd.north_tile = tile + GetHouseNorthPart(house); // modifies 'house'!
    00241
    00242   /* Use a pointer for the tile to start the search. Will be required for calculating the distance*/
    00243   if (CircularTileSearch(&found_tile, 2 * searchradius + 1, search_procs[searchtype], &nbhd)) {
    00244     return DistanceManhattan(found_tile, tile);
    00245   }
    00246   return 0;
    00247 }
    00248
    00254 static uint32 HouseGetVariable(const ResolverObject *object, byte variable, byte parameter, bool *available)
    00255 {
    00256   const Town *town = object->u.house.town;
    00257   TileIndex tile   = object->u.house.tile;
    00258   HouseID house_id = object->u.house.house_id;
    00259
    00260   if (object->scope == VSG_SCOPE_PARENT) {
    00261     return TownGetVariable(variable, parameter, available, town);
    00262   }
    00263
    00264   switch (variable) {
    00265     /* Construction stage. */
    00266     case 0x40: return (IsTileType(tile, MP_HOUSE) ? GetHouseBuildingStage(tile) : 0) | TileHash2Bit(TileX(tile), TileY(tile)) << 2;
    00267
    00268     /* Building age. */
    00269     case 0x41: return IsTileType(tile, MP_HOUSE) ? GetHouseAge(tile) : 0;
    00270
    00271     /* Town zone */
    00272     case 0x42: return GetTownRadiusGroup(town, tile);
    00273
    00274     /* Terrain type */
    00275     case 0x43: return GetTerrainType(tile);
    00276
    00277     /* Number of this type of building on the map. */
    00278     case 0x44: return GetNumHouses(house_id, town);
    00279
    00280     /* Whether the town is being created or just expanded. */
    00281     case 0x45: return _generating_world ? 1 : 0;
    00282
    00283     /* Current animation frame. */
    00284     case 0x46: return IsTileType(tile, MP_HOUSE) ? GetHouseAnimationFrame(tile) : 0;
    00285
    00286     /* Position of the house */
    00287     case 0x47: return TileY(tile) << 16 | TileX(tile);
    00288
    00289     /* Building counts for old houses with id = parameter. */
    00290     case 0x60: return GetNumHouses(parameter, town);
    00291
    00292     /* Building counts for new houses with id = parameter. */
    00293     case 0x61: {
    00294       const HouseSpec *hs = HouseSpec::Get(house_id);
    00295       if (hs->grffile == NULL) return 0;
    00296
    00297       HouseID new_house = _house_mngr.GetID(parameter, hs->grffile->grfid);
    00298       return new_house == INVALID_HOUSE_ID ? 0 : GetNumHouses(new_house, town);
    00299     }
    00300
    00301     /* Land info for nearby tiles. */
    00302     case 0x62: return GetNearbyTileInformation(parameter, tile);
    00303
    00304     /* Current animation frame of nearby house tiles */
    00305     case 0x63: {
    00306       TileIndex testtile = GetNearbyTile(parameter, tile);
    00307       return IsTileType(testtile, MP_HOUSE) ? GetHouseAnimationFrame(testtile) : 0;
    00308     }
    00309
    00310     /* Cargo acceptance history of nearby stations */
    00311     /*case 0x64: not implemented yet */
    00312
    00313     /* Distance test for some house types */
    00314     case 0x65: return GetDistanceFromNearbyHouse(parameter, tile, object->u.house.house_id);
    00315
    00316     /* Class and ID of nearby house tile */
    00317     case 0x66: {
    00318       TileIndex testtile = GetNearbyTile(parameter, tile);
    00319       if (!IsTileType(testtile, MP_HOUSE)) return 0xFFFFFFFF;
    00320       HouseSpec *hs = HouseSpec::Get(GetHouseType(testtile));
    00321       /* Information about the grf local classid if the house has a class */
    00322       uint houseclass = 0;
    00323       if (hs->class_id != HOUSE_NO_CLASS) {
    00324         houseclass = (hs->grffile == object->grffile ? 1 : 2) << 8;
    00325         houseclass |= _class_mapping[hs->class_id].class_id;
    00326       }
    00327       /* old house type or grf-local houseid */
    00328       uint local_houseid = 0;
    00329       if (house_id < NEW_HOUSE_OFFSET) {
    00330         local_houseid = house_id;
    00331       } else {
    00332         local_houseid = (hs->grffile == object->grffile ? 1 : 2) << 8;
    00333         local_houseid |= hs->local_id;
    00334       }
    00335       return houseclass << 16 | local_houseid;
    00336     }
    00337
    00338     /* GRFID of nearby house tile */
    00339     case 0x67: {
    00340       TileIndex testtile = GetNearbyTile(parameter, tile);
    00341       if (!IsTileType(testtile, MP_HOUSE)) return 0xFFFFFFFF;
    00342       HouseID house_id = GetHouseType(testtile);
    00343       if (house_id < NEW_HOUSE_OFFSET) return 0;
    00344       /* Checking the grffile information via HouseSpec doesn't work
    00345        * in case the newgrf was removed. */
    00346       return _house_mngr.mapping_ID[house_id].grfid;
    00347     }
    00348   }
    00349
    00350   DEBUG(grf, 1, "Unhandled house property 0x%X", variable);
    00351
    00352   *available = false;
    00353   return UINT_MAX;
    00354 }
    00355
    00356 static const SpriteGroup *HouseResolveReal(const ResolverObject *object, const RealSpriteGroup *group)
    00357 {
    00358   /* Houses do not have 'real' groups */
    00359   return NULL;
    00360 }
    00361
    00367 static void NewHouseResolver(ResolverObject *res, HouseID house_id, TileIndex tile, Town *town)
    00368 {
    00369   res->GetRandomBits = HouseGetRandomBits;
    00370   res->GetTriggers   = HouseGetTriggers;
    00371   res->SetTriggers   = HouseSetTriggers;
    00372   res->GetVariable   = HouseGetVariable;
    00373   res->ResolveReal   = HouseResolveReal;
    00374
    00375   res->u.house.tile     = tile;
    00376   res->u.house.town     = town;
    00377   res->u.house.house_id = house_id;
    00378   res->u.house.not_yet_constructed = false;
    00379
    00380   res->callback        = CBID_NO_CALLBACK;
    00381   res->callback_param1 = 0;
    00382   res->callback_param2 = 0;
    00383   res->last_value      = 0;
    00384   res->trigger         = 0;
    00385   res->reseed          = 0;
    00386   res->count           = 0;
    00387
    00388   const HouseSpec *hs = HouseSpec::Get(house_id);
    00389   res->grffile         = (hs != NULL ? hs->grffile : NULL);
    00390 }
    00391
    00392 uint16 GetHouseCallback(CallbackID callback, uint32 param1, uint32 param2, HouseID house_id, Town *town, TileIndex tile, bool not_yet_constructed)
    00393 {
    00394   ResolverObject object;
    00395   const SpriteGroup *group;
    00396
    00397   assert(IsValidTile(tile) && (not_yet_constructed || IsTileType(tile, MP_HOUSE)));
    00398
    00399   NewHouseResolver(&object, house_id, tile, town);
    00400   object.callback = callback;
    00401   object.callback_param1 = param1;
    00402   object.callback_param2 = param2;
    00403   object.u.house.not_yet_constructed = not_yet_constructed;
    00404
    00405   group = SpriteGroup::Resolve(HouseSpec::Get(house_id)->spritegroup, &object);
    00406   if (group == NULL) return CALLBACK_FAILED;
    00407
    00408   return group->GetCallbackResult();
    00409 }
    00410
    00411 static void DrawTileLayout(const TileInfo *ti, const TileLayoutSpriteGroup *group, byte stage, HouseID house_id)
    00412 {
    00413   const DrawTileSprites *dts = group->dts;
    00414
    00415   const HouseSpec *hs = HouseSpec::Get(house_id);
    00416   PaletteID palette = hs->random_colour[TileHash2Bit(ti->x, ti->y)] + PALETTE_RECOLOUR_START;
    00417   if (HasBit(hs->callback_mask, CBM_HOUSE_COLOUR)) {
    00418     uint16 callback = GetHouseCallback(CBID_HOUSE_COLOUR, 0, 0, house_id, Town::GetByTile(ti->tile), ti->tile);
    00419     if (callback != CALLBACK_FAILED) {
    00420       /* If bit 14 is set, we should use a 2cc colour map, else use the callback value. */
    00421       palette = HasBit(callback, 14) ? GB(callback, 0, 8) + SPR_2CCMAP_BASE : callback;
    00422     }
    00423   }
    00424
    00425   SpriteID image = dts->ground.sprite;
    00426   PaletteID pal  = dts->ground.pal;
    00427
    00428   if (HasBit(image, SPRITE_MODIFIER_CUSTOM_SPRITE)) image += stage;
    00429
    00430   if (GB(image, 0, SPRITE_WIDTH) != 0) {
    00431     DrawGroundSprite(image, GroundSpritePaletteTransform(image, pal, palette));
    00432   }
    00433
    00434   DrawNewGRFTileSeq(ti, dts, TO_HOUSES, stage, palette);
    00435 }
    00436
    00437 void DrawNewHouseTile(TileInfo *ti, HouseID house_id)
    00438 {
    00439   const HouseSpec *hs = HouseSpec::Get(house_id);
    00440   const SpriteGroup *group;
    00441   ResolverObject object;
    00442
    00443   if (ti->tileh != SLOPE_FLAT) {
    00444     bool draw_old_one = true;
    00445     if (HasBit(hs->callback_mask, CBM_HOUSE_DRAW_FOUNDATIONS)) {
    00446       /* Called to determine the type (if any) of foundation to draw for the house tile */
    00447       uint32 callback_res = GetHouseCallback(CBID_HOUSE_DRAW_FOUNDATIONS, 0, 0, house_id, Town::GetByTile(ti->tile), ti->tile);
    00448       draw_old_one = (callback_res != 0);
    00449     }
    00450
    00451     if (draw_old_one) DrawFoundation(ti, FOUNDATION_LEVELED);
    00452   }
    00453
    00454   NewHouseResolver(&object, house_id, ti->tile, Town::GetByTile(ti->tile));
    00455
    00456   group = SpriteGroup::Resolve(hs->spritegroup, &object);
    00457   if (group == NULL || group->type != SGT_TILELAYOUT) {
    00458     return;
    00459   } else {
    00460     /* Limit the building stage to the number of stages supplied. */
    00461     const TileLayoutSpriteGroup *tlgroup = (const TileLayoutSpriteGroup *)group;
    00462     byte stage = GetHouseBuildingStage(ti->tile);
    00463     stage = Clamp(stage - 4 + tlgroup->num_building_stages, 0, tlgroup->num_building_stages - 1);
    00464     DrawTileLayout(ti, tlgroup, stage, house_id);
    00465   }
    00466 }
    00467
    00468 void AnimateNewHouseTile(TileIndex tile)
    00469 {
    00470   const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
    00471   byte animation_speed = hs->animation_speed;
    00472   bool frame_set_by_callback = false;
    00473
    00474   if (HasBit(hs->callback_mask, CBM_HOUSE_ANIMATION_SPEED)) {
    00475     uint16 callback_res = GetHouseCallback(CBID_HOUSE_ANIMATION_SPEED, 0, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
    00476     if (callback_res != CALLBACK_FAILED) animation_speed = Clamp(callback_res & 0xFF, 2, 16);
    00477   }
    00478
    00479   /* An animation speed of 2 means the animation frame changes 4 ticks, and
    00480    * increasing this value by one doubles the wait. 2 is the minimum value
    00481    * allowed for animation_speed, which corresponds to 120ms, and 16 is the
    00482    * maximum, corresponding to around 33 minutes. */
    00483   if (_tick_counter % (1 << animation_speed) != 0) return;
    00484
    00485   byte frame      = GetHouseAnimationFrame(tile);
    00486   byte num_frames = GB(hs->animation_frames, 0, 7);
    00487
    00488   if (HasBit(hs->callback_mask, CBM_HOUSE_ANIMATION_NEXT_FRAME)) {
    00489     uint32 param = (hs->extra_flags & CALLBACK_1A_RANDOM_BITS) ? Random() : 0;
    00490     uint16 callback_res = GetHouseCallback(CBID_HOUSE_ANIMATION_NEXT_FRAME, param, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
    00491
    00492     if (callback_res != CALLBACK_FAILED) {
    00493       frame_set_by_callback = true;
    00494
    00495       switch (callback_res & 0xFF) {
    00496         case 0xFF:
    00497           DeleteAnimatedTile(tile);
    00498           break;
    00499         case 0xFE:
    00500           /* Carry on as normal. */
    00501           frame_set_by_callback = false;
    00502           break;
    00503         default:
    00504           frame = callback_res & 0xFF;
    00505           break;
    00506       }
    00507
    00508       /* If the lower 7 bits of the upper byte of the callback
    00509        * result are not empty, it is a sound effect. */
    00510       if (GB(callback_res, 8, 7) != 0) PlayTileSound(hs->grffile, GB(callback_res, 8, 7), tile);
    00511     }
    00512   }
    00513
    00514   if (!frame_set_by_callback) {
    00515     if (frame < num_frames) {
    00516       frame++;
    00517     } else if (frame == num_frames && HasBit(hs->animation_frames, 7)) {
    00518       /* This animation loops, so start again from the beginning */
    00519       frame = 0;
    00520     } else {
    00521       /* This animation doesn't loop, so stay here */
    00522       DeleteAnimatedTile(tile);
    00523     }
    00524   }
    00525
    00526   SetHouseAnimationFrame(tile, frame);
    00527   MarkTileDirtyByTile(tile);
    00528 }
    00529
    00530 void ChangeHouseAnimationFrame(const GRFFile *file, TileIndex tile, uint16 callback_result)
    00531 {
    00532   switch (callback_result & 0xFF) {
    00533     case 0xFD: /* Do nothing. */         break;
    00534     case 0xFE: AddAnimatedTile(tile);    break;
    00535     case 0xFF: DeleteAnimatedTile(tile); break;
    00536     default:
    00537       SetHouseAnimationFrame(tile, callback_result & 0xFF);
    00538       AddAnimatedTile(tile);
    00539       break;
    00540   }
    00541   /* If the lower 7 bits of the upper byte of the callback
    00542    * result are not empty, it is a sound effect. */
    00543   if (GB(callback_result, 8, 7) != 0) PlayTileSound(file, GB(callback_result, 8, 7), tile);
    00544 }
    00545
    00546 bool CanDeleteHouse(TileIndex tile)
    00547 {
    00548   const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
    00549
    00550   /* Humans are always allowed to remove buildings, as is water and
    00551    * anyone using the scenario editor. */
    00552   if (Company::IsValidHumanID(_current_company) || _current_company == OWNER_WATER || _current_company == OWNER_NONE) {
    00553     return true;
    00554   }
    00555
    00556   if (HasBit(hs->callback_mask, CBM_HOUSE_DENY_DESTRUCTION)) {
    00557     uint16 callback_res = GetHouseCallback(CBID_HOUSE_DENY_DESTRUCTION, 0, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
    00558     return (callback_res == CALLBACK_FAILED || callback_res == 0);
    00559   } else {
    00560     return !(hs->extra_flags & BUILDING_IS_PROTECTED);
    00561   }
    00562 }
    00563
    00564 static void AnimationControl(TileIndex tile, uint16 random_bits)
    00565 {
    00566   const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
    00567
    00568   if (HasBit(hs->callback_mask, CBM_HOUSE_ANIMATION_START_STOP)) {
    00569     uint32 param = (hs->extra_flags & SYNCHRONISED_CALLBACK_1B) ? (GB(Random(), 0, 16) | random_bits << 16) : Random();
    00570     uint16 callback_res = GetHouseCallback(CBID_HOUSE_ANIMATION_START_STOP, param, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
    00571
    00572     if (callback_res != CALLBACK_FAILED) ChangeHouseAnimationFrame(hs->grffile, tile, callback_res);
    00573   }
    00574 }
    00575
    00576 bool NewHouseTileLoop(TileIndex tile)
    00577 {
    00578   const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
    00579
    00580   if (GetHouseProcessingTime(tile) > 0) {
    00581     DecHouseProcessingTime(tile);
    00582     return true;
    00583   }
    00584
    00585   TriggerHouse(tile, HOUSE_TRIGGER_TILE_LOOP);
    00586   if (hs->building_flags & BUILDING_HAS_1_TILE) TriggerHouse(tile, HOUSE_TRIGGER_TILE_LOOP_TOP);
    00587
    00588   if (HasBit(hs->callback_mask, CBM_HOUSE_ANIMATION_START_STOP)) {
    00589     /* If this house is marked as having a synchronised callback, all the
    00590      * tiles will have the callback called at once, rather than when the
    00591      * tile loop reaches them. This should only be enabled for the northern
    00592      * tile, or strange things will happen (here, and in TTDPatch). */
    00593     if (hs->extra_flags & SYNCHRONISED_CALLBACK_1B) {
    00594       uint16 random = GB(Random(), 0, 16);
    00595
    00596       if (hs->building_flags & BUILDING_HAS_1_TILE)  AnimationControl(tile, random);
    00597       if (hs->building_flags & BUILDING_2_TILES_Y)   AnimationControl(TILE_ADDXY(tile, 0, 1), random);
    00598       if (hs->building_flags & BUILDING_2_TILES_X)   AnimationControl(TILE_ADDXY(tile, 1, 0), random);
    00599       if (hs->building_flags & BUILDING_HAS_4_TILES) AnimationControl(TILE_ADDXY(tile, 1, 1), random);
    00600     } else {
    00601       AnimationControl(tile, 0);
    00602     }
    00603   }
    00604
    00605   /* Check callback 21, which determines if a house should be destroyed. */
    00606   if (HasBit(hs->callback_mask, CBM_HOUSE_DESTRUCTION)) {
    00607     uint16 callback_res = GetHouseCallback(CBID_HOUSE_DESTRUCTION, 0, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
    00608     if (callback_res != CALLBACK_FAILED && GB(callback_res, 0, 8) > 0) {
    00609       ClearTownHouse(Town::GetByTile(tile), tile);
    00610       return false;
    00611     }
    00612   }
    00613
    00614   SetHouseProcessingTime(tile, hs->processing_time);
    00615   MarkTileDirtyByTile(tile);
    00616   return true;
    00617 }
    00618
    00619 static void DoTriggerHouse(TileIndex tile, HouseTrigger trigger, byte base_random, bool first)
    00620 {
    00621   ResolverObject object;
    00622
    00623   /* We can't trigger a non-existent building... */
    00624   assert(IsTileType(tile, MP_HOUSE));
    00625
    00626   HouseID hid = GetHouseType(tile);
    00627   HouseSpec *hs = HouseSpec::Get(hid);
    00628
    00629   if (hs->spritegroup == NULL) return;
    00630
    00631   NewHouseResolver(&object, hid, tile, Town::GetByTile(tile));
    00632
    00633   object.callback = CBID_RANDOM_TRIGGER;
    00634   object.trigger = trigger;
    00635
    00636   const SpriteGroup *group = SpriteGroup::Resolve(hs->spritegroup, &object);
    00637   if (group == NULL) return;
    00638
    00639   byte new_random_bits = Random();
    00640   byte random_bits = GetHouseRandomBits(tile);
    00641   random_bits &= ~object.reseed;
    00642   random_bits |= (first ? new_random_bits : base_random) & object.reseed;
    00643   SetHouseRandomBits(tile, random_bits);
    00644
    00645   switch (trigger) {
    00646     case HOUSE_TRIGGER_TILE_LOOP:
    00647       /* Random value already set. */
    00648       break;
    00649
    00650     case HOUSE_TRIGGER_TILE_LOOP_TOP:
    00651       if (!first) {
    00652         /* The top tile is marked dirty by the usual TileLoop */
    00653         MarkTileDirtyByTile(tile);
    00654         break;
    00655       }
    00656       /* Random value of first tile already set. */
    00657       if (hs->building_flags & BUILDING_2_TILES_Y)   DoTriggerHouse(TILE_ADDXY(tile, 0, 1), trigger, random_bits, false);
    00658       if (hs->building_flags & BUILDING_2_TILES_X)   DoTriggerHouse(TILE_ADDXY(tile, 1, 0), trigger, random_bits, false);
    00659       if (hs->building_flags & BUILDING_HAS_4_TILES) DoTriggerHouse(TILE_ADDXY(tile, 1, 1), trigger, random_bits, false);
    00660       break;
    00661   }
    00662 }
    00663
    00664 void TriggerHouse(TileIndex t, HouseTrigger trigger)
    00665 {
    00666   DoTriggerHouse(t, trigger, 0, true);
    00667 }