Add special cell for objects created via Lua scripts and not yet added into the world

apps/openmw/mwlua/luabindings.cpp

@@ -21,8 +21,8 @@
 #include "../mwworld/class.hpp"
 #include "../mwworld/esmstore.hpp"
 #include "../mwworld/manualref.hpp"
-#include "../mwworld/scene.hpp"
 #include "../mwworld/store.hpp"
+#include "../mwworld/worldmodel.hpp"
 
 #include "luaevents.hpp"
 #include "luamanagerimp.hpp"
@@ -226,13 +226,11 @@ namespace MWLua
         api["activeActors"] = GObjectList{ worldView->getActorsInScene() };
         api["players"] = GObjectList{ worldView->getPlayers() };
         api["createObject"] = [](std::string_view recordId, sol::optional<int> count) -> GObject {
-            // Doesn't matter which cell to use because the new object will be in disabled state.
-            MWWorld::CellStore* cell = MWBase::Environment::get().getWorldScene()->getCurrentCell();
-
             MWWorld::ManualRef mref(*MWBase::Environment::get().getESMStore(), ESM::RefId::deserializeText(recordId));
             const MWWorld::Ptr& ptr = mref.getPtr();
             ptr.getRefData().disable();
-            MWWorld::Ptr newPtr = ptr.getClass().copyToCell(ptr, *cell, count.value_or(1));
+            MWWorld::CellStore& cell = MWBase::Environment::get().getWorldModel()->getDraftCell();
+            MWWorld::Ptr newPtr = ptr.getClass().copyToCell(ptr, cell, count.value_or(1));
             return GObject(newPtr);
         };
         api["getObjectByFormId"] = [](std::string_view formIdStr) -> GObject {

apps/openmw/mwlua/objectbindings.cpp

@@ -182,7 +182,8 @@ namespace MWLua
                 [](const ObjectT& o) -> std::string { return o.ptr().getCellRef().getRefId().serializeText(); });
             objectT["cell"] = sol::readonly_property([](const ObjectT& o) -> sol::optional<Cell<ObjectT>> {
                 const MWWorld::Ptr& ptr = o.ptr();
-                if (ptr.isInCell())
+                MWWorld::WorldModel* wm = MWBase::Environment::get().getWorldModel();
+                if (ptr.isInCell() && ptr.getCell() != &wm->getDraftCell())
                     return Cell<ObjectT>{ ptr.getCell() };
                 else
                     return sol::nullopt;

apps/openmw/mwworld/worldmodel.cpp

@@ -26,6 +26,8 @@ namespace MWWorld
 {
     namespace
     {
+        const ESM::RefId draftCellId = ESM::RefId::index(ESM::REC_CSTA, 0);
+
         template <class T>
         CellStore& emplaceCellStore(ESM::RefId id, const T& cell, ESMStore& store, ESM::ReadersCache& readers,
             std::unordered_map<ESM::RefId, CellStore>& cells)
@@ -159,6 +161,7 @@ MWWorld::WorldModel::WorldModel(MWWorld::ESMStore& store, ESM::ReadersCache& rea
     , mReaders(readers)
     , mIdCache(Settings::cells().mPointersCacheSize, { ESM::RefId(), nullptr })
 {
+    mDraftCell.mId = draftCellId;
 }
 
 namespace MWWorld
@@ -229,6 +232,13 @@ namespace MWWorld
         if (it != mCells.end())
             return &it->second;
 
+        if (id == draftCellId)
+        {
+            CellStore& cellStore = emplaceCellStore(id, Cell(mDraftCell), mStore, mReaders, mCells);
+            cellStore.load();
+            return &cellStore;
+        }
+
         if (const auto* exteriorId = id.getIf<ESM::ESM3ExteriorCellRefId>())
             return &getExterior(
                 ESM::ExteriorCellLocation(exteriorId->getX(), exteriorId->getY(), ESM::Cell::sDefaultWorldspaceId),
@@ -261,6 +271,11 @@ namespace MWWorld
         return *result;
     }
 
+    CellStore& WorldModel::getDraftCell() const
+    {
+        return getCell(draftCellId);
+    }
+
     CellStore* WorldModel::findCell(std::string_view name, bool forceLoad) const
     {
         if (CellStore* const cellStore = findInterior(name, forceLoad))

apps/openmw/mwworld/worldmodel.hpp

@@ -53,6 +53,10 @@ namespace MWWorld
 
         CellStore& getCell(ESM::RefId Id, bool forceLoad = true) const;
 
+        // Returns a special cell that is never active. Can be used for creating objects
+        // without adding them to the scene.
+        CellStore& getDraftCell() const;
+
         CellStore* findInterior(std::string_view name, bool forceLoad = true) const;
 
         CellStore& getInterior(std::string_view name, bool forceLoad = true) const;
@@ -103,6 +107,7 @@ namespace MWWorld
         mutable std::unordered_map<ESM::RefId, CellStore> mCells;
         mutable std::map<std::string, CellStore*, Misc::StringUtils::CiComp> mInteriors;
         mutable std::map<ESM::ExteriorCellLocation, CellStore*> mExteriors;
+        ESM::Cell mDraftCell;
         std::vector<std::pair<ESM::RefId, CellStore*>> mIdCache;
         std::size_t mIdCacheIndex = 0;
         PtrRegistry mPtrRegistry;