/**
 * @note Used by the resolver to get values for feature 07 deterministic spritegroups.
 */
/* virtual */ uint32 HouseScopeResolver::GetVariable(byte variable, uint32 parameter, bool *available) const
{
	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) : 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.grffile == NULL) return 0;

			HouseID new_house = _house_mngr.GetID(parameter, hs->grf_prop.grffile->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: {
			CargoID cid = GetCargoTranslation(parameter, this->ro->grffile);
			if (cid == CT_INVALID) return 0;

			/* Extract tile offset. */
			int8 x_offs = GB(GetRegister(0x100), 0, 8);
			int8 y_offs = GB(GetRegister(0x100), 8, 8);
			TileIndex testtile = TILE_MASK(this->tile + TileDiffXY(x_offs, y_offs));

			StationFinder stations(TileArea(testtile, 1, 1));
			const StationList *sl = stations.GetStations();

			/* Collect acceptance stats. */
			uint32 res = 0;
			for (Station * const * st_iter = sl->Begin(); st_iter != sl->End(); st_iter++) {
				const Station *st = *st_iter;
				if (HasBit(st->goods[cid].acceptance_pickup, GoodsEntry::GES_EVER_ACCEPTED))    SetBit(res, 0);
				if (HasBit(st->goods[cid].acceptance_pickup, GoodsEntry::GES_LAST_MONTH))       SetBit(res, 1);
				if (HasBit(st->goods[cid].acceptance_pickup, GoodsEntry::GES_CURRENT_MONTH))    SetBit(res, 2);
				if (HasBit(st->goods[cid].acceptance_pickup, GoodsEntry::GES_ACCEPTED_BIGTICK)) SetBit(res, 3);
			}

			/* Cargo triggered CB 148? */
			if (HasBit(this->watched_cargo_triggers, cid)) 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;
			HouseSpec *hs = HouseSpec::Get(GetHouseType(testtile));
			/* 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 (this->house_id < NEW_HOUSE_OFFSET) {
				local_houseid = this->house_id;
			} else {
				local_houseid = (hs->grf_prop.grffile == this->ro->grffile ? 1 : 2) << 8;
				local_houseid |= hs->grf_prop.local_id;
			}
			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);
		}
	}

	DEBUG(grf, 1, "Unhandled house variable 0x%X", variable);

	*available = false;
	return UINT_MAX;
}
/**
 * HouseGetVariable():
 *
 * Used by the resolver to get values for feature 07 deterministic spritegroups.
 */
static uint32 HouseGetVariable(const ResolverObject *object, byte variable, byte parameter, bool *available)
{
	const Town *town = object->u.house.town;
	TileIndex tile   = object->u.house.tile;
	HouseID house_id = object->u.house.house_id;

	if (object->scope == VSG_SCOPE_PARENT) {
		return TownGetVariable(variable, parameter, available, town);
	}

	switch (variable) {
		/* Construction stage. */
		case 0x40: return (IsTileType(tile, MP_HOUSE) ? GetHouseBuildingStage(tile) : 0) | TileHash2Bit(TileX(tile), TileY(tile)) << 2;

		/* Building age. */
		case 0x41: return IsTileType(tile, MP_HOUSE) ? GetHouseAge(tile) : 0;

		/* Town zone */
		case 0x42: return GetTownRadiusGroup(town, tile);

		/* Terrain type */
		case 0x43: return GetTerrainType(tile);

		/* Number of this type of building on the map. */
		case 0x44: return GetNumHouses(house_id, town);

		/* Whether the town is being created or just expanded. */
		case 0x45: return _generating_world ? 1 : 0;

		/* Current animation frame. */
		case 0x46: return IsTileType(tile, MP_HOUSE) ? GetHouseAnimationFrame(tile) : 0;

		/* Position of the house */
		case 0x47: return TileY(tile) << 16 | TileX(tile);

		/* Building counts for old houses with id = parameter. */
		case 0x60: return GetNumHouses(parameter, town);

		/* Building counts for new houses with id = parameter. */
		case 0x61: {
			const HouseSpec *hs = HouseSpec::Get(house_id);
			if (hs->grffile == NULL) return 0;

			HouseID new_house = _house_mngr.GetID(parameter, hs->grffile->grfid);
			return new_house == INVALID_HOUSE_ID ? 0 : GetNumHouses(new_house, town);
		}

		/* Land info for nearby tiles. */
		case 0x62: return GetNearbyTileInformation(parameter, tile);

		/* Current animation frame of nearby house tiles */
		case 0x63: {
			TileIndex testtile = GetNearbyTile(parameter, tile);
			return IsTileType(testtile, MP_HOUSE) ? GetHouseAnimationFrame(testtile) : 0;
		}

		/* Cargo acceptance history of nearby stations */
		/*case 0x64: not implemented yet */

		/* Distance test for some house types */
		case 0x65: return GetDistanceFromNearbyHouse(parameter, tile, object->u.house.house_id);

		/* Class and ID of nearby house tile */
		case 0x66: {
			TileIndex testtile = GetNearbyTile(parameter, tile);
			if (!IsTileType(testtile, MP_HOUSE)) return 0xFFFFFFFF;
			HouseSpec *hs = HouseSpec::Get(GetHouseType(testtile));
			/* Information about the grf local classid if the house has a class */
			uint houseclass = 0;
			if (hs->class_id != HOUSE_NO_CLASS) {
				houseclass = (hs->grffile == object->grffile ? 1 : 2) << 8;
				houseclass |= _class_mapping[hs->class_id].class_id;
			}
			/* old house type or grf-local houseid */
			uint local_houseid = 0;
			if (house_id < NEW_HOUSE_OFFSET) {
				local_houseid = house_id;
			} else {
				local_houseid = (hs->grffile == object->grffile ? 1 : 2) << 8;
				local_houseid |= hs->local_id;
			}
			return houseclass << 16 | local_houseid;
		}

		/* GRFID of nearby house tile */
		case 0x67: {
			TileIndex testtile = GetNearbyTile(parameter, 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.mapping_ID[house_id].grfid;
		}
	}

	DEBUG(grf, 1, "Unhandled house property 0x%X", variable);

	*available = false;
	return UINT_MAX;
}