Better handling of water levels for exterior cells.

Especially for skyrim and it's weird water level values in exteriors.
If we don't have a valid exterior water level we use the world's water level

apps/openmw/mwworld/cell.cpp

@@ -2,8 +2,12 @@
 
 #include <components/esm3/loadcell.hpp>
 #include <components/esm4/loadcell.hpp>
+#include <components/esm4/loadwrld.hpp>
 #include <components/misc/algorithm.hpp>
 
+#include "../mwbase/environment.hpp"
+#include "esmstore.hpp"
+
 namespace MWWorld
 {
     Cell::Cell(const ESM4::Cell& cell)
@@ -26,6 +30,12 @@ namespace MWWorld
             .mFogDensity = 1.f,}
             ,mWaterHeight(cell.mWaterHeight)
     {
+        if (isExterior() && mWaterHeight == ESM4::Cell::sInvalidWaterLevel)
+        {
+            auto& worldStore = MWBase::Environment::get().getESMStore()->get<ESM4::World>();
+            const ESM4::World* cellWorld = worldStore.find(mParent);
+            mWaterHeight = cellWorld->mWaterLevel;
+        }
     }
 
     Cell::Cell(const ESM::Cell& cell)
@@ -48,6 +58,8 @@ namespace MWWorld
         }
         ,mWaterHeight(cell.mWater)
     {
+        if (isExterior())
+            mWaterHeight = -1.f;
     }
 
     std::string Cell::getDescription() const

apps/openmw/mwworld/cellstore.cpp

@@ -664,7 +664,7 @@ namespace MWWorld
     float CellStore::getWaterLevel() const
     {
         if (isExterior())
-            return -1;
+            return getCell()->getWaterHeight();
         return mWaterLevel;
     }
 

components/esm4/loadcell.cpp

@@ -33,6 +33,7 @@
 #include <cassert>
 #include <cfloat> // FLT_MAX for gcc
 #include <iostream> // FIXME: debug only
+#include <limits>
 #include <stdexcept>
 
 #include "grouptype.hpp"
@@ -41,6 +42,8 @@
 
 #include <components/esm/refid.hpp>
 
+float ESM4::Cell::sInvalidWaterLevel = std::numeric_limits<float>::min();
+
 // TODO: Try loading only EDID and XCLC (along with mFormId, mFlags and mParent)
 //
 // But, for external cells we may be scanning the whole record since we don't know if there is
@@ -55,7 +58,7 @@ void ESM4::Cell::load(ESM4::Reader& reader)
     mId = ESM::RefId::formIdRefId(mFormId);
     mFlags = reader.hdr().record.flags;
     mParent = ESM::RefId::formIdRefId(reader.currWorld());
-
+    mWaterHeight = sInvalidWaterLevel;
     reader.clearCellGrid(); // clear until XCLC FIXME: somehow do this automatically?
 
     // Sometimes cell 0,0 does not have an XCLC sub record (e.g. ToddLand 000009BF)
@@ -237,7 +240,8 @@ void ESM4::Cell::load(ESM4::Reader& reader)
                 throw std::runtime_error("ESM4::CELL::load - Unknown subrecord " + ESM::printName(subHdr.typeId));
         }
     }
-
+    if (mWaterHeight > 1e8) // A Bit of a hack for skyrim, there is a value for the cell but it is all wrong.
+        mWaterHeight = sInvalidWaterLevel;
     mReaderContext = reader.getContext();
 }
 

components/esm4/loadcell.hpp

@@ -107,6 +107,8 @@ namespace ESM4
         int getGridX() const { return mX; }
         int getGridY() const { return mY; }
         bool isExterior() const { return !(mCellFlags & CELL_Interior); }
+
+        static float sInvalidWaterLevel;
     };
 }