Increase ESM4 active grid

apps/openmw/mwworld/scene.cpp

@@ -779,6 +779,7 @@ namespace MWWorld
 
     void Scene::changePlayerCell(CellStore& cell, const ESM::Position& pos, bool adjustPlayerPos)
     {
+        mHalfGridSize = cell.getCell()->isEsm4() ? Constants::ESM4CellGridRadius : Constants::CellGridRadius;
         mCurrentCell = &cell;
 
         mRendering.enableTerrain(cell.isExterior());

apps/openmw/mwworld/scene.hpp

@@ -102,7 +102,7 @@ namespace MWWorld
         bool mPreloadFastTravel;
         float mPredictionTime;
 
-        static const int mHalfGridSize = Constants::CellGridRadius;
+        int mHalfGridSize = Constants::CellGridRadius;
 
         osg::Vec3f mLastPlayerPos;
 

components/misc/constants.hpp

@@ -28,6 +28,9 @@ namespace Constants
     // Size of active cell grid in cells (it is a square with the (2 * CellGridRadius + 1) cells side)
     constexpr int CellGridRadius = 1;
 
+    // ESM4 cells are twice smaller, so the active grid should have more cells.
+    constexpr int ESM4CellGridRadius = CellGridRadius * 2;
+
     // A label to mark night/day visual switches
     const std::string NightDayLabel = "NightDaySwitch";