newgrf_house.cpp

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/*
 * This file is part of OpenTTD.
 * 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.
 * 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.
 * 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/>.
 */
 
#include "stdafx.h"
#include "debug.h"
#include "landscape.h"
#include "newgrf_badge.h"
#include "newgrf_house.h"
#include "newgrf_spritegroup.h"
#include "newgrf_town.h"
#include "newgrf_sound.h"
#include "company_func.h"
#include "company_base.h"
#include "town.h"
#include "genworld.h"
#include "newgrf_animation_base.h"
#include "newgrf_cargo.h"
#include "station_base.h"
 
#include "safeguards.h"
 
static BuildingCounts<uint32_t> _building_counts{};
static std::vector<HouseClassMapping> _class_mapping{};
 
HouseOverrideManager _house_mngr(NEW_HOUSE_OFFSET, NUM_HOUSES, INVALID_HOUSE_ID);
 
static const GRFFile *GetHouseSpecGrf(HouseID house_id)
{
  const HouseSpec *hs  = HouseSpec::Get(house_id);
  return (hs != nullptr) ? hs->grf_prop.grffile : nullptr;
}
 
extern const HouseSpec _original_house_specs[NEW_HOUSE_OFFSET];
std::vector<HouseSpec> _house_specs;
 
std::vector<HouseSpec> &HouseSpec::Specs()
{
  return _house_specs;
}
 
HouseID HouseSpec::Index() const
{
  return static_cast<HouseID>(this - _house_specs.data());
}
 
HouseSpec *HouseSpec::Get(size_t house_id)
{
  /* Empty house if index is out of range -- this might happen if NewGRFs are changed. */
  static HouseSpec empty = {};
 
  assert(house_id < NUM_HOUSES);
  if (house_id >= _house_specs.size()) return &empty;
  return &_house_specs[house_id];
}
 
/* Reset and initialise house specs. */
void ResetHouses()
{
  _house_specs.clear();
  _house_specs.reserve(std::size(_original_house_specs));
 
  ResetHouseClassIDs();
 
  /* Copy default houses. */
  _house_specs.insert(std::end(_house_specs), std::begin(_original_house_specs), std::end(_original_house_specs));
 
  /* Reset any overrides that have been set. */
  _house_mngr.ResetOverride();
}
 
HouseResolverObject::HouseResolverObject(HouseID house_id, TileIndex tile, Town *town,
    CallbackID callback, uint32_t param1, uint32_t param2,
    bool not_yet_constructed, uint8_t initial_random_bits, CargoTypes watched_cargo_triggers, int view)
  : ResolverObject(GetHouseSpecGrf(house_id), callback, param1, param2),
  house_scope(*this, house_id, tile, town, not_yet_constructed, initial_random_bits, watched_cargo_triggers, view),
  town_scope(*this, town, not_yet_constructed) // Don't access StorePSA if house is not yet constructed.
{
  /* Tile must be valid and a house tile, unless not yet constructed in which case it may also be INVALID_TILE. */
  assert((IsValidTile(tile) && (not_yet_constructed || IsTileType(tile, MP_HOUSE))) || (not_yet_constructed && tile == INVALID_TILE));
 
  this->root_spritegroup = HouseSpec::Get(house_id)->grf_prop.GetSpriteGroup();
}
 
GrfSpecFeature HouseResolverObject::GetFeature() const
{
  return GSF_HOUSES;
}
 
uint32_t HouseResolverObject::GetDebugID() const
{
  return HouseSpec::Get(this->house_scope.house_id)->grf_prop.local_id;
}
 
void ResetHouseClassIDs()
{
  _class_mapping.clear();
 
  /* Add initial entry for HOUSE_NO_CLASS. */
  _class_mapping.emplace_back();
}
 
HouseClassID AllocateHouseClassID(uint8_t grf_class_id, uint32_t grfid)
{
  /* Start from 1 because 0 means that no class has been assigned. */
  auto it = std::find_if(std::next(std::begin(_class_mapping)), std::end(_class_mapping), [grf_class_id, grfid](const HouseClassMapping &map) { return map.class_id == grf_class_id && map.grfid == grfid; });
 
  /* HouseClass not found, allocate a new one. */
  if (it == std::end(_class_mapping)) it = _class_mapping.insert(it, {.grfid = grfid, .class_id = grf_class_id});
 
  return static_cast<HouseClassID>(std::distance(std::begin(_class_mapping), it));
}
 
void InitializeBuildingCounts(Town *t)
{
  t->cache.building_counts.id_count.clear();
  t->cache.building_counts.class_count.clear();
  t->cache.building_counts.id_count.resize(HouseSpec::Specs().size());
  t->cache.building_counts.class_count.resize(_class_mapping.size());
}
 
void InitializeBuildingCounts()
{
  _building_counts.id_count.clear();
  _building_counts.class_count.clear();
  _building_counts.id_count.resize(HouseSpec::Specs().size());
  _building_counts.class_count.resize(_class_mapping.size());
 
  for (Town *t : Town::Iterate()) {
    InitializeBuildingCounts(t);
  }
}
 
std::span<const uint> GetBuildingHouseIDCounts()
{
  return _building_counts.id_count;
}
 
void IncreaseBuildingCount(Town *t, HouseID house_id)
{
  HouseClassID class_id = HouseSpec::Get(house_id)->class_id;
 
  t->cache.building_counts.id_count[house_id]++;
  _building_counts.id_count[house_id]++;
 
  if (class_id == HOUSE_NO_CLASS) return;
 
  t->cache.building_counts.class_count[class_id]++;
  _building_counts.class_count[class_id]++;
}
 
void DecreaseBuildingCount(Town *t, HouseID house_id)
{
  HouseClassID class_id = HouseSpec::Get(house_id)->class_id;
 
  if (t->cache.building_counts.id_count[house_id] > 0) t->cache.building_counts.id_count[house_id]--;
  if (_building_counts.id_count[house_id] > 0) _building_counts.id_count[house_id]--;
 
  if (class_id == HOUSE_NO_CLASS) return;
 
  if (t->cache.building_counts.class_count[class_id] > 0) t->cache.building_counts.class_count[class_id]--;
  if (_building_counts.class_count[class_id] > 0) _building_counts.class_count[class_id]--;
}
 
/* virtual */ uint32_t HouseScopeResolver::GetRandomBits() const
{
  /* Note: Towns build houses over houses. So during construction checks 'tile' may be a valid but unrelated house. */
  return this->not_yet_constructed ? this->initial_random_bits : GetHouseRandomBits(this->tile);
}
 
/* virtual */ uint32_t HouseScopeResolver::GetTriggers() const
{
  /* Note: Towns build houses over houses. So during construction checks 'tile' may be a valid but unrelated house. */
  return this->not_yet_constructed ? 0 : GetHouseTriggers(this->tile);
}
 
static uint32_t GetNumHouses(HouseID house_id, const Town *town)
{
  HouseClassID class_id = HouseSpec::Get(house_id)->class_id;
 
  uint8_t map_id_count     = ClampTo<uint8_t>(_building_counts.id_count[house_id]);
  uint8_t map_class_count  = ClampTo<uint8_t>(_building_counts.class_count[class_id]);
  uint8_t town_id_count    = ClampTo<uint8_t>(town->cache.building_counts.id_count[house_id]);
  uint8_t town_class_count = ClampTo<uint8_t>(town->cache.building_counts.class_count[class_id]);
 
  return map_class_count << 24 | town_class_count << 16 | map_id_count << 8 | town_id_count;
}
 
static uint32_t GetNearbyTileInformation(uint8_t parameter, TileIndex tile, bool grf_version8)
{
  tile = GetNearbyTile(parameter, tile);
  return GetNearbyTileInformation(tile, grf_version8);
}
 
struct SearchNearbyHouseData {
  const HouseSpec *hs;  
  TileIndex north_tile; 
};
 
static bool SearchNearbyHouseID(TileIndex tile, void *user_data)
{
  if (IsTileType(tile, MP_HOUSE)) {
    HouseID house = GetHouseType(tile); // tile been examined
    const HouseSpec *hs = HouseSpec::Get(house);
    if (hs->grf_prop.HasGrfFile()) { // must be one from a grf file
      SearchNearbyHouseData *nbhd = (SearchNearbyHouseData *)user_data;
 
      TileIndex north_tile = tile + GetHouseNorthPart(house); // modifies 'house'!
      if (north_tile == nbhd->north_tile) return false; // Always ignore origin house
 
      return hs->grf_prop.local_id == nbhd->hs->grf_prop.local_id &&  // same local id as the one requested
        hs->grf_prop.grfid == nbhd->hs->grf_prop.grfid;  // from the same grf
    }
  }
  return false;
}
 
static bool SearchNearbyHouseClass(TileIndex tile, void *user_data)
{
  if (IsTileType(tile, MP_HOUSE)) {
    HouseID house = GetHouseType(tile); // tile been examined
    const HouseSpec *hs = HouseSpec::Get(house);
    if (hs->grf_prop.HasGrfFile()) { // must be one from a grf file
      SearchNearbyHouseData *nbhd = (SearchNearbyHouseData *)user_data;
 
      TileIndex north_tile = tile + GetHouseNorthPart(house); // modifies 'house'!
      if (north_tile == nbhd->north_tile) return false; // Always ignore origin house
 
      return hs->class_id == nbhd->hs->class_id &&  // same classid as the one requested
        hs->grf_prop.grfid == nbhd->hs->grf_prop.grfid;  // from the same grf
    }
  }
  return false;
}
 
static bool SearchNearbyHouseGRFID(TileIndex tile, void *user_data)
{
  if (IsTileType(tile, MP_HOUSE)) {
    HouseID house = GetHouseType(tile); // tile been examined
    const HouseSpec *hs = HouseSpec::Get(house);
    if (hs->grf_prop.HasGrfFile()) { // must be one from a grf file
      SearchNearbyHouseData *nbhd = (SearchNearbyHouseData *)user_data;
 
      TileIndex north_tile = tile + GetHouseNorthPart(house); // modifies 'house'!
      if (north_tile == nbhd->north_tile) return false; // Always ignore origin house
 
      return hs->grf_prop.grfid == nbhd->hs->grf_prop.grfid;  // from the same grf
    }
  }
  return false;
}
 
static uint32_t GetDistanceFromNearbyHouse(uint8_t parameter, TileIndex tile, HouseID house)
{
  static TestTileOnSearchProc * const search_procs[3] = {
    SearchNearbyHouseID,
    SearchNearbyHouseClass,
    SearchNearbyHouseGRFID,
  };
  TileIndex found_tile = tile;
  uint8_t searchtype = GB(parameter, 6, 2);
  uint8_t searchradius = GB(parameter, 0, 6);
  if (searchtype >= lengthof(search_procs)) return 0;  // do not run on ill-defined code
  if (searchradius < 1) return 0; // do not use a too low radius
 
  SearchNearbyHouseData nbhd;
  nbhd.hs = HouseSpec::Get(house);
  nbhd.north_tile = tile + GetHouseNorthPart(house); // modifies 'house'!
 
  /* Use a pointer for the tile to start the search. Will be required for calculating the distance*/
  if (CircularTileSearch(&found_tile, 2 * searchradius + 1, search_procs[searchtype], &nbhd)) {
    return DistanceManhattan(found_tile, tile);
  }
  return 0;
}
 
/* virtual */ uint32_t HouseScopeResolver::GetVariable(uint8_t variable, [[maybe_unused]] uint32_t parameter, bool &available) const
{
  if (this->tile == INVALID_TILE) {
    /* House does not yet exist, nor is it being planned to exist. Provide some default values instead. */
    switch (variable) {
      case 0x40: return TOWN_HOUSE_COMPLETED | this->view << 2; /* Construction stage. */
      case 0x41: return 0;
      case 0x42: return 0;
      case 0x43: return 0;
      case 0x44: return 0;
      case 0x45: return _generating_world ? 1 : 0;
      case 0x46: return 0;
      case 0x47: return 0;
      case 0x60: return 0;
      case 0x61: return 0;
      case 0x62: return 0;
      case 0x63: return 0;
      case 0x64: return 0;
      case 0x65: return 0;
      case 0x66: return 0xFFFFFFFF; /* Class and ID of nearby house. */
      case 0x67: return 0;
 
      case 0x7A: return GetBadgeVariableResult(*this->ro.grffile, HouseSpec::Get(this->house_id)->badges, parameter);
    }
 
    Debug(grf, 1, "Unhandled house variable 0x{:X}", variable);
    available = false;
    return UINT_MAX;
  }
 
  switch (variable) {
    /* Construction stage. */
    case 0x40: return (IsTileType(this->tile, MP_HOUSE) ? GetHouseBuildingStage(this->tile) : 0) | TileHash2Bit(TileX(this->tile), TileY(this->tile)) << 2;
 
    /* Building age. */
    case 0x41: return IsTileType(this->tile, MP_HOUSE) ? GetHouseAge(this->tile).base() : 0;
 
    /* Town zone */
    case 0x42: return GetTownRadiusGroup(this->town, this->tile);
 
    /* Terrain type */
    case 0x43: return GetTerrainType(this->tile);
 
    /* Number of this type of building on the map. */
    case 0x44: return GetNumHouses(this->house_id, this->town);
 
    /* Whether the town is being created or just expanded. */
    case 0x45: return _generating_world ? 1 : 0;
 
    /* Current animation frame. */
    case 0x46: return IsTileType(this->tile, MP_HOUSE) ? GetAnimationFrame(this->tile) : 0;
 
    /* Position of the house */
    case 0x47: return TileY(this->tile) << 16 | TileX(this->tile);
 
    /* Building counts for old houses with id = parameter. */
    case 0x60: return parameter < NEW_HOUSE_OFFSET ? GetNumHouses(parameter, this->town) : 0;
 
    /* Building counts for new houses with id = parameter. */
    case 0x61: {
      const HouseSpec *hs = HouseSpec::Get(this->house_id);
      if (!hs->grf_prop.HasGrfFile()) return 0;
 
      HouseID new_house = _house_mngr.GetID(parameter, hs->grf_prop.grfid);
      return new_house == INVALID_HOUSE_ID ? 0 : GetNumHouses(new_house, this->town);
    }
 
    /* Land info for nearby tiles. */
    case 0x62: return GetNearbyTileInformation(parameter, this->tile, this->ro.grffile->grf_version >= 8);
 
    /* Current animation frame of nearby house tiles */
    case 0x63: {
      TileIndex testtile = GetNearbyTile(parameter, this->tile);
      return IsTileType(testtile, MP_HOUSE) ? GetAnimationFrame(testtile) : 0;
    }
 
    /* Cargo acceptance history of nearby stations */
    case 0x64: {
      CargoType cargo_type = GetCargoTranslation(parameter, this->ro.grffile);
      if (!IsValidCargoType(cargo_type)) return 0;
 
      /* Extract tile offset. */
      int8_t x_offs = GB(GetRegister(0x100), 0, 8);
      int8_t y_offs = GB(GetRegister(0x100), 8, 8);
      TileIndex testtile = Map::WrapToMap(this->tile + TileDiffXY(x_offs, y_offs));
 
      StationFinder stations(TileArea(testtile, 1, 1));
 
      /* Collect acceptance stats. */
      uint32_t res = 0;
      for (Station *st : stations.GetStations()) {
        if (HasBit(st->goods[cargo_type].status, GoodsEntry::GES_EVER_ACCEPTED))    SetBit(res, 0);
        if (HasBit(st->goods[cargo_type].status, GoodsEntry::GES_LAST_MONTH))       SetBit(res, 1);
        if (HasBit(st->goods[cargo_type].status, GoodsEntry::GES_CURRENT_MONTH))    SetBit(res, 2);
        if (HasBit(st->goods[cargo_type].status, GoodsEntry::GES_ACCEPTED_BIGTICK)) SetBit(res, 3);
      }
 
      /* Cargo triggered CB 148? */
      if (HasBit(this->watched_cargo_triggers, cargo_type)) SetBit(res, 4);
 
      return res;
    }
 
    /* Distance test for some house types */
    case 0x65: return GetDistanceFromNearbyHouse(parameter, this->tile, this->house_id);
 
    /* Class and ID of nearby house tile */
    case 0x66: {
      TileIndex testtile = GetNearbyTile(parameter, this->tile);
      if (!IsTileType(testtile, MP_HOUSE)) return 0xFFFFFFFF;
      HouseID nearby_house_id = GetHouseType(testtile);
      HouseSpec *hs = HouseSpec::Get(nearby_house_id);
      /* Information about the grf local classid if the house has a class */
      uint houseclass = 0;
      if (hs->class_id != HOUSE_NO_CLASS) {
        houseclass = (hs->grf_prop.grffile == this->ro.grffile ? 1 : 2) << 8;
        houseclass |= _class_mapping[hs->class_id].class_id;
      }
      /* old house type or grf-local houseid */
      uint local_houseid = 0;
      if (nearby_house_id < NEW_HOUSE_OFFSET) {
        local_houseid = nearby_house_id;
      } else {
        local_houseid = (hs->grf_prop.grffile == this->ro.grffile ? 1 : 2) << 8;
        local_houseid |= ClampTo<uint8_t>(hs->grf_prop.local_id); // Spec only allows 8 bits, so all local-ids above 254 are clamped.
      }
      return houseclass << 16 | local_houseid;
    }
 
    /* GRFID of nearby house tile */
    case 0x67: {
      TileIndex testtile = GetNearbyTile(parameter, this->tile);
      if (!IsTileType(testtile, MP_HOUSE)) return 0xFFFFFFFF;
      HouseID house_id = GetHouseType(testtile);
      if (house_id < NEW_HOUSE_OFFSET) return 0;
      /* Checking the grffile information via HouseSpec doesn't work
       * in case the newgrf was removed. */
      return _house_mngr.GetGRFID(house_id);
    }
 
    case 0x7A: return GetBadgeVariableResult(*this->ro.grffile, HouseSpec::Get(this->house_id)->badges, parameter);
  }
 
  Debug(grf, 1, "Unhandled house variable 0x{:X}", variable);
 
  available = false;
  return UINT_MAX;
}
 
uint16_t GetHouseCallback(CallbackID callback, uint32_t param1, uint32_t param2, HouseID house_id, Town *town, TileIndex tile,
    bool not_yet_constructed, uint8_t initial_random_bits, CargoTypes watched_cargo_triggers, int view)
{
  HouseResolverObject object(house_id, tile, town, callback, param1, param2,
      not_yet_constructed, initial_random_bits, watched_cargo_triggers, view);
  return object.ResolveCallback();
}
 
static void DrawTileLayout(const TileInfo *ti, const TileLayoutSpriteGroup *group, uint8_t stage, HouseID house_id)
{
  const DrawTileSprites *dts = group->ProcessRegisters(&stage);
 
  const HouseSpec *hs = HouseSpec::Get(house_id);
  PaletteID palette = GENERAL_SPRITE_COLOUR(hs->random_colour[TileHash2Bit(ti->x, ti->y)]);
  if (hs->callback_mask.Test(HouseCallbackMask::Colour)) {
    uint16_t callback = GetHouseCallback(CBID_HOUSE_COLOUR, 0, 0, house_id, Town::GetByTile(ti->tile), ti->tile);
    if (callback != CALLBACK_FAILED) {
      /* If bit 14 is set, we should use a 2cc colour map, else use the callback value. */
      palette = HasBit(callback, 14) ? GB(callback, 0, 8) + SPR_2CCMAP_BASE : callback;
    }
  }
 
  SpriteID image = dts->ground.sprite;
  PaletteID pal  = dts->ground.pal;
 
  if (HasBit(image, SPRITE_MODIFIER_CUSTOM_SPRITE)) image += stage;
  if (HasBit(pal, SPRITE_MODIFIER_CUSTOM_SPRITE)) pal += stage;
 
  if (GB(image, 0, SPRITE_WIDTH) != 0) {
    DrawGroundSprite(image, GroundSpritePaletteTransform(image, pal, palette));
  }
 
  DrawNewGRFTileSeq(ti, dts, TO_HOUSES, stage, palette);
}
 
void DrawNewHouseTile(TileInfo *ti, HouseID house_id)
{
  const HouseSpec *hs = HouseSpec::Get(house_id);
 
  if (ti->tileh != SLOPE_FLAT) {
    bool draw_old_one = true;
    if (hs->callback_mask.Test(HouseCallbackMask::DrawFoundations)) {
      /* Called to determine the type (if any) of foundation to draw for the house tile */
      uint32_t callback_res = GetHouseCallback(CBID_HOUSE_DRAW_FOUNDATIONS, 0, 0, house_id, Town::GetByTile(ti->tile), ti->tile);
      if (callback_res != CALLBACK_FAILED) draw_old_one = ConvertBooleanCallback(hs->grf_prop.grffile, CBID_HOUSE_DRAW_FOUNDATIONS, callback_res);
    }
 
    if (draw_old_one) DrawFoundation(ti, FOUNDATION_LEVELED);
  }
 
  HouseResolverObject object(house_id, ti->tile, Town::GetByTile(ti->tile));
 
  const SpriteGroup *group = object.Resolve();
  if (group != nullptr && group->type == SGT_TILELAYOUT) {
    /* Limit the building stage to the number of stages supplied. */
    const TileLayoutSpriteGroup *tlgroup = (const TileLayoutSpriteGroup *)group;
    uint8_t stage = GetHouseBuildingStage(ti->tile);
    DrawTileLayout(ti, tlgroup, stage, house_id);
  }
}
 
/* Simple wrapper for GetHouseCallback to keep the animation unified. */
uint16_t GetSimpleHouseCallback(CallbackID callback, uint32_t param1, uint32_t param2, const HouseSpec *spec, Town *town, TileIndex tile, CargoTypes extra_data)
{
  return GetHouseCallback(callback, param1, param2, spec - HouseSpec::Get(0), town, tile, false, 0, extra_data);
}
 
struct HouseAnimationBase : public AnimationBase<HouseAnimationBase, HouseSpec, Town, CargoTypes, GetSimpleHouseCallback, TileAnimationFrameAnimationHelper<Town> > {
  static constexpr CallbackID cb_animation_speed      = CBID_HOUSE_ANIMATION_SPEED;
  static constexpr CallbackID cb_animation_next_frame = CBID_HOUSE_ANIMATION_NEXT_FRAME;
 
  static constexpr HouseCallbackMask cbm_animation_speed      = HouseCallbackMask::AnimationSpeed;
  static constexpr HouseCallbackMask cbm_animation_next_frame = HouseCallbackMask::AnimationNextFrame;
};
 
void AnimateNewHouseTile(TileIndex tile)
{
  const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
  if (hs == nullptr) return;
 
  HouseAnimationBase::AnimateTile(hs, Town::GetByTile(tile), tile, hs->extra_flags.Test(HouseExtraFlag::Callback1ARandomBits));
}
 
void AnimateNewHouseConstruction(TileIndex tile)
{
  const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
 
  if (hs->callback_mask.Test(HouseCallbackMask::ConstructionStateChange)) {
    HouseAnimationBase::ChangeAnimationFrame(CBID_HOUSE_CONSTRUCTION_STATE_CHANGE, hs, Town::GetByTile(tile), tile, 0, 0);
  }
}
 
bool CanDeleteHouse(TileIndex tile)
{
  const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
 
  /* Humans are always allowed to remove buildings, as is water and disasters and
   * anyone using the scenario editor. */
  if (Company::IsValidHumanID(_current_company) || _current_company == OWNER_WATER || _current_company == OWNER_NONE || _game_mode == GM_EDITOR || _generating_world) {
    return true;
  }
 
  if (hs->callback_mask.Test(HouseCallbackMask::DenyDestruction)) {
    uint16_t callback_res = GetHouseCallback(CBID_HOUSE_DENY_DESTRUCTION, 0, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
    return (callback_res == CALLBACK_FAILED || !ConvertBooleanCallback(hs->grf_prop.grffile, CBID_HOUSE_DENY_DESTRUCTION, callback_res));
  } else {
    return !IsHouseProtected(tile);
  }
}
 
static void AnimationControl(TileIndex tile, uint16_t random_bits)
{
  const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
 
  if (hs->callback_mask.Test(HouseCallbackMask::AnimationStartStop)) {
    uint32_t param = hs->extra_flags.Test(HouseExtraFlag::SynchronisedCallback1B) ? (GB(Random(), 0, 16) | random_bits << 16) : Random();
    HouseAnimationBase::ChangeAnimationFrame(CBID_HOUSE_ANIMATION_START_STOP, hs, Town::GetByTile(tile), tile, param, 0);
  }
}
 
bool NewHouseTileLoop(TileIndex tile)
{
  const HouseSpec *hs = HouseSpec::Get(GetHouseType(tile));
 
  if (GetHouseProcessingTime(tile) > 0) {
    DecHouseProcessingTime(tile);
    return true;
  }
 
  TriggerHouse(tile, HOUSE_TRIGGER_TILE_LOOP);
  if (hs->building_flags.Any(BUILDING_HAS_1_TILE)) TriggerHouse(tile, HOUSE_TRIGGER_TILE_LOOP_TOP);
 
  if (hs->callback_mask.Test(HouseCallbackMask::AnimationStartStop)) {
    /* If this house is marked as having a synchronised callback, all the
     * tiles will have the callback called at once, rather than when the
     * tile loop reaches them. This should only be enabled for the northern
     * tile, or strange things will happen (here, and in TTDPatch). */
    if (hs->extra_flags.Test(HouseExtraFlag::SynchronisedCallback1B)) {
      uint16_t random = GB(Random(), 0, 16);
 
      if (hs->building_flags.Any(BUILDING_HAS_1_TILE))  AnimationControl(tile, random);
      if (hs->building_flags.Any(BUILDING_2_TILES_Y))   AnimationControl(TileAddXY(tile, 0, 1), random);
      if (hs->building_flags.Any(BUILDING_2_TILES_X))   AnimationControl(TileAddXY(tile, 1, 0), random);
      if (hs->building_flags.Any(BUILDING_HAS_4_TILES)) AnimationControl(TileAddXY(tile, 1, 1), random);
    } else {
      AnimationControl(tile, 0);
    }
  }
 
  /* Check callback 21, which determines if a house should be destroyed. */
  if (hs->callback_mask.Test(HouseCallbackMask::Destruction)) {
    uint16_t callback_res = GetHouseCallback(CBID_HOUSE_DESTRUCTION, 0, 0, GetHouseType(tile), Town::GetByTile(tile), tile);
    if (callback_res != CALLBACK_FAILED && Convert8bitBooleanCallback(hs->grf_prop.grffile, CBID_HOUSE_DESTRUCTION, callback_res)) {
      ClearTownHouse(Town::GetByTile(tile), tile);
      return false;
    }
  }
 
  SetHouseProcessingTime(tile, hs->processing_time);
  MarkTileDirtyByTile(tile);
  return true;
}
 
static void DoTriggerHouse(TileIndex tile, HouseTrigger trigger, uint8_t base_random, bool first)
{
  /* We can't trigger a non-existent building... */
  assert(IsTileType(tile, MP_HOUSE));
 
  HouseID hid = GetHouseType(tile);
  HouseSpec *hs = HouseSpec::Get(hid);
 
  if (hs->grf_prop.GetSpriteGroup() == nullptr) return;
 
  HouseResolverObject object(hid, tile, Town::GetByTile(tile), CBID_RANDOM_TRIGGER);
  object.waiting_triggers = GetHouseTriggers(tile) | trigger;
  SetHouseTriggers(tile, object.waiting_triggers); // store now for var 5F
 
  const SpriteGroup *group = object.Resolve();
  if (group == nullptr) return;
 
  /* Store remaining triggers. */
  SetHouseTriggers(tile, object.GetRemainingTriggers());
 
  /* Rerandomise bits. Scopes other than SELF are invalid for houses. For bug-to-bug-compatibility with TTDP we ignore the scope. */
  uint8_t new_random_bits = Random();
  uint8_t random_bits = GetHouseRandomBits(tile);
  uint32_t reseed = object.GetReseedSum();
  random_bits &= ~reseed;
  random_bits |= (first ? new_random_bits : base_random) & reseed;
  SetHouseRandomBits(tile, random_bits);
 
  switch (trigger) {
    case HOUSE_TRIGGER_TILE_LOOP:
      /* Random value already set. */
      break;
 
    case HOUSE_TRIGGER_TILE_LOOP_TOP:
      if (!first) {
        /* The top tile is marked dirty by the usual TileLoop */
        MarkTileDirtyByTile(tile);
        break;
      }
      /* Random value of first tile already set. */
      if (hs->building_flags.Any(BUILDING_2_TILES_Y))   DoTriggerHouse(TileAddXY(tile, 0, 1), trigger, random_bits, false);
      if (hs->building_flags.Any(BUILDING_2_TILES_X))   DoTriggerHouse(TileAddXY(tile, 1, 0), trigger, random_bits, false);
      if (hs->building_flags.Any(BUILDING_HAS_4_TILES)) DoTriggerHouse(TileAddXY(tile, 1, 1), trigger, random_bits, false);
      break;
  }
}
 
void TriggerHouse(TileIndex t, HouseTrigger trigger)
{
  DoTriggerHouse(t, trigger, 0, true);
}
 
void DoWatchedCargoCallback(TileIndex tile, TileIndex origin, CargoTypes trigger_cargoes, uint16_t random)
{
  TileIndexDiffC diff = TileIndexToTileIndexDiffC(origin, tile);
  uint32_t cb_info = random << 16 | (uint8_t)diff.y << 8 | (uint8_t)diff.x;
  HouseAnimationBase::ChangeAnimationFrame(CBID_HOUSE_WATCHED_CARGO_ACCEPTED, HouseSpec::Get(GetHouseType(tile)), Town::GetByTile(tile), tile, 0, cb_info, trigger_cargoes);
}
 
void WatchedCargoCallback(TileIndex tile, CargoTypes trigger_cargoes)
{
  assert(IsTileType(tile, MP_HOUSE));
  HouseID id = GetHouseType(tile);
  const HouseSpec *hs = HouseSpec::Get(id);
 
  trigger_cargoes &= hs->watched_cargoes;
  /* None of the trigger cargoes is watched? */
  if (trigger_cargoes == 0) return;
 
  /* Same random value for all tiles of a multi-tile house. */
  uint16_t r = Random();
 
  /* Do the callback, start at northern tile. */
  TileIndex north = tile + GetHouseNorthPart(id);
  hs = HouseSpec::Get(id);
 
  DoWatchedCargoCallback(north, tile, trigger_cargoes, r);
  if (hs->building_flags.Any(BUILDING_2_TILES_Y))   DoWatchedCargoCallback(TileAddXY(north, 0, 1), tile, trigger_cargoes, r);
  if (hs->building_flags.Any(BUILDING_2_TILES_X))   DoWatchedCargoCallback(TileAddXY(north, 1, 0), tile, trigger_cargoes, r);
  if (hs->building_flags.Any(BUILDING_HAS_4_TILES)) DoWatchedCargoCallback(TileAddXY(north, 1, 1), tile, trigger_cargoes, r);
}