Nothing can be loaded yet. Just foundations.

apps/openmw/mwworld/cellstore.hpp

@@ -51,10 +51,17 @@ namespace ESM
     struct BodyPart;
 }
 
+namespace ESM4
+{
+    class Reader;
+    struct Cell;
+}
+
 namespace MWWorld
 {
     class ESMStore;
     struct CellStoreImp;
+    typedef std::variant<const ESM4::Cell*, const ESM::Cell*> CellVariant;
 
     using CellStoreTuple = std::tuple<CellRefList<ESM::Activator>, CellRefList<ESM::Potion>,
         CellRefList<ESM::Apparatus>, CellRefList<ESM::Armor>, CellRefList<ESM::Book>, CellRefList<ESM::Clothing>,
@@ -86,6 +93,7 @@ namespace MWWorld
         std::unique_ptr<ESM::FogState> mFogState;
 
         const ESM::Cell* mCell;
+        CellVariant mCellVariant;
         State mState;
         bool mHasState;
         std::vector<ESM::RefId> mIds;

apps/openmw/mwworld/store.cpp

@@ -1183,6 +1183,31 @@ namespace MWWorld
         }
         return name;
     }
+
+    // ESM4 Cell
+    //=========================================================================
+
+    const ESM4::Cell* Store<ESM4::Cell>::searchCellName(std::string_view cellName) const
+    {
+        const auto foundCell = mCellNameIndex.find(cellName);
+        if (foundCell == mCellNameIndex.end())
+            return nullptr;
+        return foundCell->second;
+    }
+
+    ESM4::Cell* Store<ESM4::Cell>::insert(const ESM4::Cell& item, bool overrideOnly)
+    {
+        auto cellPtr = TypedDynamicStore<ESM4::Cell>::insert(item, overrideOnly);
+        mCellNameIndex[cellPtr->mEditorId] = cellPtr;
+        return cellPtr;
+    }
+
+    ESM4::Cell* Store<ESM4::Cell>::insertStatic(const ESM4::Cell& item)
+    {
+        auto cellPtr = TypedDynamicStore<ESM4::Cell>::insertStatic(item);
+        mCellNameIndex[cellPtr->mEditorId] = cellPtr;
+        return cellPtr;
+    }
 }
 
 template class MWWorld::TypedDynamicStore<ESM::Activator>;

apps/openmw/mwworld/store.hpp

@@ -15,6 +15,7 @@
 #include <components/esm3/loadgmst.hpp>
 #include <components/esm3/loadland.hpp>
 #include <components/esm3/loadpgrd.hpp>
+#include <components/esm4/loadcell.hpp>
 #include <components/misc/rng.hpp>
 #include <components/misc/strings/algorithm.hpp>
 
@@ -268,6 +269,19 @@ namespace MWWorld
         const ESM::GameSetting* find(const std::string_view id) const;
         const ESM::GameSetting* search(const std::string_view id) const;
     };
+
+    template <>
+    class Store<ESM4::Cell> : public TypedDynamicStore<ESM4::Cell>
+    {
+        std::unordered_map<std::string, ESM4::Cell*, Misc::StringUtils::CiHash, Misc::StringUtils::CiEqual>
+            mCellNameIndex;
+
+    public:
+        const ESM4::Cell* searchCellName(std::string_view) const;
+        ESM4::Cell* insert(const ESM4::Cell& item, bool overrideOnly = false);
+        ESM4::Cell* insertStatic(const ESM4::Cell& item);
+    };
+
     template <>
     class Store<ESM::Land> : public DynamicStore
     {

apps/openmw/mwworld/worldmodel.cpp

@@ -253,6 +253,17 @@ const ESM::Cell* MWWorld::WorldModel::getESMCellByName(std::string_view name)
     return cell;
 }
 
+MWWorld::CellVariant MWWorld::WorldModel::getCellByName(std::string_view name)
+{
+    const ESM::Cell* cellEsm3 = getESMCellByName(name);
+    return cellEsm3;
+    if (!cellEsm3)
+    {
+        const ESM4::Cell* cellESM4 = mStore.get<ESM4::Cell>().searchCellName(name);
+        return cellESM4;
+    }
+}
+
 MWWorld::CellStore* MWWorld::WorldModel::getCell(std::string_view name)
 {
     const ESM::Cell* cell = getESMCellByName(name);

apps/openmw/mwworld/worldmodel.hpp

@@ -5,6 +5,7 @@
 #include <map>
 #include <string>
 #include <unordered_map>
+#include <variant>
 
 #include <components/misc/algorithm.hpp>
 
@@ -21,6 +22,11 @@ namespace ESM
     struct RefNum;
 }
 
+namespace ESM4
+{
+    struct Cell;
+}
+
 namespace Loading
 {
     class Listener;
@@ -45,8 +51,9 @@ namespace MWWorld
         WorldModel& operator=(const WorldModel&);
 
         const ESM::Cell* getESMCellByName(std::string_view name);
-        CellStore* getCellStore(const ESM::Cell* cell);
+        CellVariant getCellByName(std::string_view name);
 
+        CellStore* getCellStore(const ESM::Cell* cell);
         Ptr getPtrAndCache(const ESM::RefId& name, CellStore& cellStore);
 
         Ptr getPtr(CellStore& cellStore, const ESM::RefId& id, const ESM::RefNum& refNum);