Add savegame conversion and version bump for more house IDs

src/saveload/afterload.cpp

@@ -1803,7 +1803,7 @@ bool AfterLoadGame()
 	}
 
 	/* Check and update house and town values */
-	UpdateHousesAndTowns(gcf_res != GLC_ALL_GOOD);
+	UpdateHousesAndTowns(gcf_res != GLC_ALL_GOOD, true);
 
 	if (IsSavegameVersionBefore(SLV_43)) {
 		for (TileIndex t = 0; t < map_size; t++) {
@@ -3878,6 +3878,15 @@ bool AfterLoadGame()
 		_settings_game.economy.inflation_fixed_dates = !IsSavegameVersionBefore(SLV_GS_INDUSTRY_CONTROL);
 	}
 
+	if (SlXvIsFeatureMissing(XSLFI_MORE_HOUSES)) {
+		for (TileIndex t = 0; t < map_size; t++) {
+			if (IsTileType(t, MP_HOUSE)) {
+				/* Move upper bit of house ID from bit 6 of m3 to bits 6..5 of m3. */
+				SB(_m[t].m3, 5, 2, GB(_m[t].m3, 6, 1));
+			}
+		}
+	}
+
 	InitializeRoadGUI();
 
 	/* This needs to be done after conversion. */
@@ -3988,7 +3997,7 @@ void ReloadNewGRFData()
 	/* Update company statistics. */
 	AfterLoadCompanyStats();
 	/* Check and update house and town values */
-	UpdateHousesAndTowns(true);
+	UpdateHousesAndTowns(true, false);
 	/* Delete news referring to no longer existing entities */
 	DeleteInvalidEngineNews();
 	/* Update livery selection windows */

src/saveload/extended_ver_sl.cpp

@@ -147,6 +147,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_REALISTIC_TRAIN_BRAKING,XSCF_NULL,                1,   1, "realistic_train_braking",   nullptr, nullptr, "VLKA"         },
 	{ XSLFI_INFLATION_FIXED_DATES,  XSCF_IGNORABLE_ALL,       1,   1, "inflation_fixed_dates",     nullptr, nullptr, nullptr        },
 	{ XSLFI_WATER_FLOODING,         XSCF_NULL,                1,   1, "water_flooding",            nullptr, nullptr, nullptr        },
+	{ XSLFI_MORE_HOUSES,            XSCF_NULL,                1,   1, "more_houses",               nullptr, nullptr, nullptr        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker
 };
 

src/saveload/extended_ver_sl.h

@@ -101,6 +101,7 @@ enum SlXvFeatureIndex {
 	XSLFI_REALISTIC_TRAIN_BRAKING,                ///< Realistic train braking
 	XSLFI_INFLATION_FIXED_DATES,                  ///< Inflation is applied between fixed dates
 	XSLFI_WATER_FLOODING,                         ///< Water flooding map bit
+	XSLFI_MORE_HOUSES,                            ///< More house types
 
 	XSLFI_RIFF_HEADER_60_BIT,                     ///< Size field in RIFF chunk header is 60 bit
 	XSLFI_HEIGHT_8_BIT,                           ///< Map tile height is 8 bit instead of 4 bit, but savegame version may be before this became true in trunk

src/saveload/saveload_internal.h

@@ -36,7 +36,7 @@ void AfterLoadStoryBook();
 void AfterLoadLinkGraphs();
 void AfterLoadCompanyStats();
 void AfterLoadTraceRestrict();
-void UpdateHousesAndTowns(bool cargo_update_required);
+void UpdateHousesAndTowns(bool cargo_update_required, bool old_map_position);
 
 void UpdateOldAircraft();
 

src/saveload/town_sl.cpp

@@ -59,17 +59,29 @@ void RebuildTownCaches(bool cargo_update_required)
  * town, the town radius and the max passengers
  * of the town.
  */
-void UpdateHousesAndTowns(bool cargo_update_required)
+void UpdateHousesAndTowns(bool cargo_update_required, bool old_map_position)
 {
+	auto get_house_type = [&](TileIndex t) -> HouseID {
+		if (old_map_position && SlXvIsFeatureMissing(XSLFI_MORE_HOUSES)) {
+			return _m[t].m4 | (GB(_m[t].m3, 6, 1) << 8);
+		} else {
+			return GetCleanHouseType(t);
+		}
+	};
 	for (TileIndex t = 0; t < MapSize(); t++) {
 		if (!IsTileType(t, MP_HOUSE)) continue;
 
-		HouseID house_id = GetCleanHouseType(t);
+		HouseID house_id = get_house_type(t);
 		if (!HouseSpec::Get(house_id)->enabled && house_id >= NEW_HOUSE_OFFSET) {
 			/* The specs for this type of house are not available any more, so
 			 * replace it with the substitute original house type. */
 			house_id = _house_mngr.GetSubstituteID(house_id);
+			if (old_map_position && SlXvIsFeatureMissing(XSLFI_MORE_HOUSES)) {
+				_m[t].m4 = GB(house_id, 0, 8);
+				SB(_m[t].m3, 6, 1, GB(house_id, 8, 1));
+			} else {
 				SetHouseType(t, house_id);
+			}
 			cargo_update_required = true;
 		}
 	}
@@ -78,24 +90,24 @@ void UpdateHousesAndTowns(bool cargo_update_required)
 	for (TileIndex t = 0; t < MapSize(); t++) {
 		if (!IsTileType(t, MP_HOUSE)) continue;
 
-		HouseID house_type = GetCleanHouseType(t);
+		HouseID house_type = get_house_type(t);
 		TileIndex north_tile = t + GetHouseNorthPart(house_type); // modifies 'house_type'!
 		if (t == north_tile) {
 			const HouseSpec *hs = HouseSpec::Get(house_type);
 			bool valid_house = true;
 			if (hs->building_flags & TILE_SIZE_2x1) {
 				TileIndex tile = t + TileDiffXY(1, 0);
-				if (!IsTileType(tile, MP_HOUSE) || GetCleanHouseType(tile) != house_type + 1) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 1) valid_house = false;
 			} else if (hs->building_flags & TILE_SIZE_1x2) {
 				TileIndex tile = t + TileDiffXY(0, 1);
-				if (!IsTileType(tile, MP_HOUSE) || GetCleanHouseType(tile) != house_type + 1) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 1) valid_house = false;
 			} else if (hs->building_flags & TILE_SIZE_2x2) {
 				TileIndex tile = t + TileDiffXY(0, 1);
-				if (!IsTileType(tile, MP_HOUSE) || GetCleanHouseType(tile) != house_type + 1) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 1) valid_house = false;
 				tile = t + TileDiffXY(1, 0);
-				if (!IsTileType(tile, MP_HOUSE) || GetCleanHouseType(tile) != house_type + 2) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 2) valid_house = false;
 				tile = t + TileDiffXY(1, 1);
-				if (!IsTileType(tile, MP_HOUSE) || GetCleanHouseType(tile) != house_type + 3) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 3) valid_house = false;
 			}
 			/* If not all tiles of this house are present remove the house.
 			 * The other tiles will get removed later in this loop because
@@ -104,7 +116,7 @@ void UpdateHousesAndTowns(bool cargo_update_required)
 				DoClearSquare(t);
 				cargo_update_required = true;
 			}
-		} else if (!IsTileType(north_tile, MP_HOUSE) || GetCleanHouseType(north_tile) != house_type) {
+		} else if (!IsTileType(north_tile, MP_HOUSE) || get_house_type(north_tile) != house_type) {
 			/* This tile should be part of a multi-tile building but the
 			 * north tile of this house isn't on the map. */
 			DoClearSquare(t);