Added support for mapping IDs for item types

Source/itemdat.cpp

@@ -24,6 +24,9 @@ namespace devilution {
 /** Contains the data related to each item ID. */
 std::vector<ItemData> AllItemsList;
 
+/** Contains item mapping IDs, with item indices assigned to them. This is used for loading saved games. */
+ankerl::unordered_dense::map<int32_t, int16_t> ItemMappingIdsToIndices;
+
 /** Contains the mapping between unique base item ID strings and indices, used for parsing additional item data. */
 ankerl::unordered_dense::map<std::string, int8_t> AdditionalUniqueBaseItemStringsToIndices;
 
@@ -548,10 +551,11 @@ tl::expected<goodorevil, std::string> ParseAffixAlignment(std::string_view value
 
 } // namespace
 
-void LoadItemDatFromFile(DataFile &dataFile, std::string_view filename)
+void LoadItemDatFromFile(DataFile &dataFile, std::string_view filename, int32_t baseMappingId)
 {
 	dataFile.skipHeaderOrDie(filename);
 
+	int32_t currentMappingId = baseMappingId;
 	AllItemsList.reserve(AllItemsList.size() + dataFile.numRecords());
 	for (DataFileRecord record : dataFile) {
 		RecordReader reader { record, filename };
@@ -579,6 +583,14 @@ void LoadItemDatFromFile(DataFile &dataFile, std::string_view filename)
 		reader.read("spell", item.iSpell, ParseSpellId);
 		reader.readBool("usable", item.iUsable);
 		reader.readInt("value", item.iValue);
+
+		item.iMappingId = currentMappingId;
+		const auto [it, inserted] = ItemMappingIdsToIndices.emplace(item.iMappingId, static_cast<int16_t>(AllItemsList.size()) - 1);
+		if (!inserted) {
+			DisplayFatalErrorAndExit("Adding Item Failed", fmt::format("An item already exists for mapping ID {}.", item.iMappingId));
+		}
+
+		++currentMappingId;
 	}
 	AllItemsList.shrink_to_fit();
 }
@@ -592,7 +604,8 @@ void LoadItemDat()
 
 	AllItemsList.clear();
 	AdditionalUniqueBaseItemStringsToIndices.clear();
-	LoadItemDatFromFile(dataFile, filename);
+	ItemMappingIdsToIndices.clear();
+	LoadItemDatFromFile(dataFile, filename, 0);
 
 	LuaEvent("ItemDataLoaded");
 }

Source/itemdat.h

@@ -80,7 +80,7 @@ enum _item_indexes : int16_t { // TODO defines all indexes in AllItemsList
 	IDI_SORCERER_DIABLO,
 	IDI_ARENAPOT,
 
-	IDI_LAST = IDI_ARENAPOT,
+	IDI_NUM_DEFAULT_ITEMS,
 	IDI_NONE = -1,
 };
 
@@ -511,6 +511,7 @@ struct ItemData {
 	SpellID iSpell;
 	bool iUsable;
 	uint16_t iValue;
+	int32_t iMappingId;
 };
 
 enum item_effect_type : int8_t {
@@ -647,12 +648,13 @@ struct UniqueItem {
 };
 
 extern DVL_API_FOR_TEST std::vector<ItemData> AllItemsList;
+extern ankerl::unordered_dense::map<int32_t, int16_t> ItemMappingIdsToIndices;
 extern std::vector<PLStruct> ItemPrefixes;
 extern std::vector<PLStruct> ItemSuffixes;
 extern DVL_API_FOR_TEST std::vector<UniqueItem> UniqueItems;
 extern ankerl::unordered_dense::map<int32_t, int32_t> UniqueItemMappingIdsToIndices;
 
-void LoadItemDatFromFile(DataFile &dataFile, std::string_view filename);
+void LoadItemDatFromFile(DataFile &dataFile, std::string_view filename, int32_t baseMappingId);
 void LoadUniqueItemDatFromFile(DataFile &dataFile, std::string_view filename, int32_t baseMappingId);
 void LoadItemData();
 

Source/loadsave.cpp

@@ -352,13 +352,21 @@ struct LevelConversionData {
 	item._iMinDex = file.NextLE<int8_t>();
 	file.Skip(1); // Alignment
 	item._iStatFlag = file.NextBool32();
-	item.IDidx = static_cast<_item_indexes>(file.NextLE<int32_t>());
-	if (gbIsSpawn) {
-		item.IDidx = RemapItemIdxFromSpawn(item.IDidx);
+
+	int32_t itemMappingId = file.NextLE<int32_t>();
+	if (gbIsSpawn && itemMappingId < IDI_NUM_DEFAULT_ITEMS) {
+		itemMappingId = RemapItemIdxFromSpawn(static_cast<_item_indexes>(itemMappingId));
+	}
+	if (!gbIsHellfireSaveGame && itemMappingId < IDI_NUM_DEFAULT_ITEMS) {
+		itemMappingId = RemapItemIdxFromDiablo(static_cast<_item_indexes>(itemMappingId));
 	}
-	if (!gbIsHellfireSaveGame) {
-		item.IDidx = RemapItemIdxFromDiablo(item.IDidx);
+	const auto findIt = ItemMappingIdsToIndices.find(itemMappingId);
+	if (findIt == ItemMappingIdsToIndices.end()) {
+		return false;
 	}
+	const _item_indexes itemIndex = static_cast<_item_indexes>(findIt->second);
+	item.IDidx = itemIndex;
+
 	item.dwBuff = file.NextLE<uint32_t>();
 	if (gbIsHellfireSaveGame)
 		item._iDamAcFlags = static_cast<ItemSpecialEffectHf>(file.NextLE<uint32_t>());
@@ -1147,11 +1155,11 @@ int getHellfireLevelType(int type)
 
 void SaveItem(SaveHelper &file, const Item &item)
 {
-	auto idx = item.IDidx;
-	if (!gbIsHellfire)
-		idx = RemapItemIdxToDiablo(idx);
-	if (gbIsSpawn)
-		idx = RemapItemIdxToSpawn(idx);
+	int32_t idx = item.IDidx != IDI_NONE ? AllItemsList[item.IDidx].iMappingId : -1;
+	if (!gbIsHellfire && idx < IDI_NUM_DEFAULT_ITEMS)
+		idx = RemapItemIdxToDiablo(static_cast<_item_indexes>(idx));
+	if (gbIsSpawn && idx < IDI_NUM_DEFAULT_ITEMS)
+		idx = RemapItemIdxToSpawn(static_cast<_item_indexes>(idx));
 	ItemType iType = item._itype;
 	if (idx == -1) {
 		idx = _item_indexes::IDI_GOLD;

Source/lua/modules/items.cpp

@@ -453,10 +453,10 @@ void RegisterItemSpecialEffectHfEnum(sol::state_view &lua)
 	    });
 }
 
-void AddItemDataFromTsv(const std::string_view path)
+void AddItemDataFromTsv(const std::string_view path, const int32_t baseMappingId)
 {
 	DataFile dataFile = DataFile::loadOrDie(path);
-	LoadItemDatFromFile(dataFile, path);
+	LoadItemDatFromFile(dataFile, path, baseMappingId);
 }
 
 void AddUniqueItemDataFromTsv(const std::string_view path, const int32_t baseMappingId)
@@ -482,7 +482,7 @@ sol::table LuaItemModule(sol::state_view &lua)
 
 	sol::table table = lua.create_table();
 
-	LuaSetDocFn(table, "addItemDataFromTsv", "(path: string)", AddItemDataFromTsv);
+	LuaSetDocFn(table, "addItemDataFromTsv", "(path: string, baseMappingId: number)", AddItemDataFromTsv);
 	LuaSetDocFn(table, "addUniqueItemDataFromTsv", "(path: string, baseMappingId: number)", AddUniqueItemDataFromTsv);
 
 	return table;