Savegame: store fog of war (Closes #1177)

apps/openmw/mwrender/localmap.cpp

@@ -9,6 +9,8 @@
 #include <OgreRenderTexture.h>
 #include <OgreViewport.h>
 
+#include <components/esm/fogstate.hpp>
+
 #include "../mwbase/environment.hpp"
 #include "../mwbase/world.hpp"
 #include "../mwbase/windowmanager.hpp"
@@ -46,7 +48,6 @@ LocalMap::LocalMap(OEngine::Render::OgreRenderer* rend, MWRender::RenderingManag
 
 LocalMap::~LocalMap()
 {
-    deleteBuffers();
 }
 
 const Ogre::Vector2 LocalMap::rotatePoint(const Ogre::Vector2& p, const Ogre::Vector2& c, const float angle)
@@ -55,59 +56,83 @@ const Ogre::Vector2 LocalMap::rotatePoint(const Ogre::Vector2& p, const Ogre::Ve
                     Math::Sin(angle) * (p.x - c.x) + Math::Cos(angle) * (p.y - c.y) + c.y);
 }
 
-void LocalMap::deleteBuffers()
+std::string LocalMap::coordStr(const int x, const int y)
-{
-    mBuffers.clear();
-}
-
-void LocalMap::saveTexture(const std::string& texname, const std::string& filename)
 {
-    TexturePtr tex = TextureManager::getSingleton().getByName(texname);
+    return StringConverter::toString(x) + "_" + StringConverter::toString(y);
-    if (tex.isNull()) return;
-    HardwarePixelBufferSharedPtr readbuffer = tex->getBuffer();
-    readbuffer->lock(HardwareBuffer::HBL_NORMAL );
-    const PixelBox &readrefpb = readbuffer->getCurrentLock();
-    uchar *readrefdata = static_cast<uchar*>(readrefpb.data);
-
-    Image img;
-    img = img.loadDynamicImage (readrefdata, tex->getWidth(),
-        tex->getHeight(), tex->getFormat());
-    img.save("./" + filename);
-
-    readbuffer->unlock();
 }
 
-std::string LocalMap::coordStr(const int x, const int y)
+void LocalMap::clear()
 {
-    return StringConverter::toString(x) + "_" + StringConverter::toString(y);
+    // Not actually removing the Textures here. That doesnt appear to work properly. It seems MyGUI still keeps some pointers.
+    mBuffers.clear();
 }
 
 void LocalMap::saveFogOfWar(MWWorld::CellStore* cell)
 {
     if (!mInterior)
     {
-        /*saveTexture("Cell_"+coordStr(mCellX, mCellY)+"_fog",
+        std::string textureName = "Cell_"+coordStr(cell->getCell()->getGridX(), cell->getCell()->getGridY())+"_fog";
-            "Cell_"+coordStr(mCellX, mCellY)+"_fog.png");*/
+        std::auto_ptr<ESM::FogState> fog (new ESM::FogState());
+        fog->mFogTextures.push_back(ESM::FogTexture());
+
+        TexturePtr tex = TextureManager::getSingleton().getByName(textureName);
+        if (tex.isNull())
+            return;
+
+        Ogre::Image image;
+        tex->convertToImage(image);
+
+        Ogre::DataStreamPtr encoded = image.encode("tga");
+        fog->mFogTextures.back().mImageData.resize(encoded->size());
+        encoded->read(&fog->mFogTextures.back().mImageData[0], encoded->size());
+
+        cell->setFog(fog.release());
     }
     else
     {
         Vector2 min(mBounds.getMinimum().x, mBounds.getMinimum().y);
         Vector2 max(mBounds.getMaximum().x, mBounds.getMaximum().y);
         Vector2 length = max-min;
-
-        // divide into segments
         const int segsX = std::ceil( length.x / sSize );
         const int segsY = std::ceil( length.y / sSize );
 
+        mInteriorName = cell->getCell()->mName;
+
+        std::auto_ptr<ESM::FogState> fog (new ESM::FogState());
+
+        fog->mBounds.mMinX = mBounds.getMinimum().x;
+        fog->mBounds.mMaxX = mBounds.getMaximum().x;
+        fog->mBounds.mMinY = mBounds.getMinimum().y;
+        fog->mBounds.mMaxY = mBounds.getMaximum().y;
+        fog->mNorthMarkerAngle = mAngle;
+
+        fog->mFogTextures.reserve(segsX*segsY);
+
         for (int x=0; x<segsX; ++x)
         {
             for (int y=0; y<segsY; ++y)
             {
-                /*saveTexture(
+                std::string textureName = cell->getCell()->mName + "_" + coordStr(x,y) + "_fog";
-                    mInteriorName + "_" + coordStr(x,y) + "_fog",
+
-                    mInteriorName + "_" + coordStr(x,y) + "_fog.png");*/
+                TexturePtr tex = TextureManager::getSingleton().getByName(textureName);
+                if (tex.isNull())
+                    return;
+
+                Ogre::Image image;
+                tex->convertToImage(image);
+
+                fog->mFogTextures.push_back(ESM::FogTexture());
+
+                Ogre::DataStreamPtr encoded = image.encode("tga");
+                fog->mFogTextures.back().mImageData.resize(encoded->size());
+                encoded->read(&fog->mFogTextures.back().mImageData[0], encoded->size());
+
+                fog->mFogTextures.back().mX = x;
+                fog->mFogTextures.back().mY = y;
             }
         }
+
+        cell->setFog(fog.release());
     }
 }
 
@@ -126,29 +151,34 @@ void LocalMap::requestMap(MWWorld::CellStore* cell, float zMin, float zMax)
     mCameraPosNode->setPosition(Vector3(0,0,0));
 
     render((x+0.5)*sSize, (y+0.5)*sSize, zMin, zMax, sSize, sSize, name);
+
+    if (mBuffers.find(name) == mBuffers.end())
+    {
+        if (cell->getFog())
+            loadFogOfWar(name, cell->getFog()->mFogTextures.back());
+        else
+            createFogOfWar(name);
+    }
 }
 
 void LocalMap::requestMap(MWWorld::CellStore* cell,
                             AxisAlignedBox bounds)
 {
-    // if we're in an empty cell, don't bother rendering anything
+    // If we're in an empty cell, bail out
+    // The operations in this function are only valid for finite bounds
     if (bounds.isNull ())
         return;
 
     mInterior = true;
-    mBounds = bounds;
 
-    float zMin = mBounds.getMinimum().z;
+    mBounds = bounds;
-    float zMax = mBounds.getMaximum().z;
 
+    // Get the cell's NorthMarker rotation. This is used to rotate the entire map.
     const Vector2& north = MWBase::Environment::get().getWorld()->getNorthVector(cell);
-    Radian angle = Ogre::Math::ATan2 (north.x, north.y);
+    Radian angle = Ogre::Math::ATan2 (north.x, north.y) + Ogre::Degree(2);
     mAngle = angle.valueRadians();
 
-    mCellCamera->setOrientation(Quaternion::IDENTITY);
+    // Rotate the cell and merge the rotated corners to the bounding box
-    mCameraRotNode->setOrientation(Quaternion(Math::Cos(mAngle/2.f), 0, 0, -Math::Sin(mAngle/2.f)));
-
-    // rotate the cell and merge the rotated corners to the bounding box
     Vector2 _center(bounds.getCenter().x, bounds.getCenter().y);
     Vector3 _c1 = bounds.getCorner(AxisAlignedBox::FAR_LEFT_BOTTOM);
     Vector3 _c2 = bounds.getCorner(AxisAlignedBox::FAR_RIGHT_BOTTOM);
@@ -168,9 +198,48 @@ void LocalMap::requestMap(MWWorld::CellStore* cell,
     mBounds.merge(Vector3(c3.x, c3.y, 0));
     mBounds.merge(Vector3(c4.x, c4.y, 0));
 
-    // apply a little padding
+    // Do NOT change padding! This will break older savegames.
-    mBounds.setMinimum (mBounds.getMinimum() - Vector3(500,500,0));
+    // If the padding really needs to be changed, then it must be saved in the ESM::FogState and
-    mBounds.setMaximum (mBounds.getMaximum() + Vector3(500,500,0));
+    // assume the old (500) value as default for older savegames.
+    const int padding = 500;
+
+    // Apply a little padding
+    mBounds.setMinimum (mBounds.getMinimum() - Vector3(padding,padding,0));
+    mBounds.setMaximum (mBounds.getMaximum() + Vector3(padding,padding,0));
+
+    float zMin = mBounds.getMinimum().z;
+    float zMax = mBounds.getMaximum().z;
+
+    // If there is fog state in the CellStore (e.g. when it came from a savegame) we need to do some checks
+    // to see if this state is still valid.
+    // Both the cell bounds and the NorthMarker rotation could be changed by the content files or exchanged models.
+    // If they changed by too much (for bounds, < padding is considered acceptable) then parts of the interior might not
+    // be covered by the map anymore.
+    // The following code detects this, and discards the CellStore's fog state if it needs to.
+    if (cell->getFog())
+    {
+        ESM::FogState* fog = cell->getFog();
+
+        Ogre::Vector3 newMin (fog->mBounds.mMinX, fog->mBounds.mMinY, zMin);
+        Ogre::Vector3 newMax (fog->mBounds.mMaxX, fog->mBounds.mMaxY, zMax);
+
+        Ogre::Vector3 minDiff = newMin - mBounds.getMinimum();
+        Ogre::Vector3 maxDiff = newMax - mBounds.getMaximum();
+
+        if (std::abs(minDiff.x) > 500 || std::abs(minDiff.y) > 500
+            || std::abs(maxDiff.x) > 500 || std::abs(maxDiff.y) > 500
+                || std::abs(mAngle - fog->mNorthMarkerAngle) > Ogre::Degree(5).valueRadians())
+        {
+            // Nuke it
+            cell->setFog(NULL);
+        }
+        else
+        {
+            // Looks sane, use it
+            mBounds = Ogre::AxisAlignedBox(newMin, newMax);
+            mAngle = fog->mNorthMarkerAngle;
+        }
+    }
 
     Vector2 center(mBounds.getCenter().x, mBounds.getCenter().y);
 
@@ -179,6 +248,9 @@ void LocalMap::requestMap(MWWorld::CellStore* cell,
 
     Vector2 length = max-min;
 
+    mCellCamera->setOrientation(Quaternion::IDENTITY);
+    mCameraRotNode->setOrientation(Quaternion(Math::Cos(mAngle/2.f), 0, 0, -Math::Sin(mAngle/2.f)));
+
     mCameraPosNode->setPosition(Vector3(center.x, center.y, 0));
 
     // divide into segments
@@ -187,17 +259,94 @@ void LocalMap::requestMap(MWWorld::CellStore* cell,
 
     mInteriorName = cell->getCell()->mName;
 
+    int i=0;
     for (int x=0; x<segsX; ++x)
     {
         for (int y=0; y<segsY; ++y)
         {
             Vector2 start = min + Vector2(sSize*x,sSize*y);
-            Vector2 newcenter = start + 4096;
+            Vector2 newcenter = start + sSize/2;
 
-            render(newcenter.x - center.x, newcenter.y - center.y, zMin, zMax, sSize, sSize,
+            std::string texturePrefix = cell->getCell()->mName + "_" + coordStr(x,y);
-                cell->getCell()->mName + "_" + coordStr(x,y));
+
+            render(newcenter.x - center.x, newcenter.y - center.y, zMin, zMax, sSize, sSize, texturePrefix);
+
+            if (!cell->getFog())
+                createFogOfWar(texturePrefix);
+            else
+            {
+                ESM::FogState* fog = cell->getFog();
+
+                // We are using the same bounds and angle as we were using when the textures were originally made. Segments should come out the same.
+                assert (i < int(fog->mFogTextures.size()));
+
+                ESM::FogTexture& esm = fog->mFogTextures[i];
+                loadFogOfWar(texturePrefix, esm);
+            }
+            ++i;
+        }
+    }
+}
+
+void LocalMap::createFogOfWar(const std::string& texturePrefix)
+{
+    const std::string texName = texturePrefix + "_fog";
+    TexturePtr tex = createFogOfWarTexture(texName);
+
+    // create a buffer to use for dynamic operations
+    std::vector<uint32> buffer;
+
+    // initialize to (0, 0, 0, 1)
+    buffer.resize(sFogOfWarResolution*sFogOfWarResolution, (255 << 24));
+
+    // upload to the texture
+    memcpy(tex->getBuffer()->lock(HardwareBuffer::HBL_DISCARD), &buffer[0], sFogOfWarResolution*sFogOfWarResolution*4);
+    tex->getBuffer()->unlock();
+
+    mBuffers[texturePrefix] = buffer;
+}
+
+Ogre::TexturePtr LocalMap::createFogOfWarTexture(const std::string &texName)
+{
+    TexturePtr tex = TextureManager::getSingleton().getByName(texName);
+    if (tex.isNull())
+    {
+        tex = TextureManager::getSingleton().createManual(
+                        texName,
+                        ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
+                        TEX_TYPE_2D,
+                        sFogOfWarResolution, sFogOfWarResolution,
+                        0,
+                        PF_A8R8G8B8,
+                        TU_DYNAMIC_WRITE_ONLY_DISCARDABLE);
     }
+    else
+        tex->unload();
+
+    return tex;
 }
+
+void LocalMap::loadFogOfWar (const std::string& texturePrefix, ESM::FogTexture& esm)
+{
+    std::vector<char>& data = esm.mImageData;
+    Ogre::DataStreamPtr stream(new Ogre::MemoryDataStream(&data[0], data.size()));
+    Ogre::Image image;
+    image.load(stream, "tga");
+
+    assert (image.getWidth() == sFogOfWarResolution && image.getHeight() == sFogOfWarResolution);
+
+    std::string texName = texturePrefix + "_fog";
+
+    Ogre::TexturePtr tex = createFogOfWarTexture(texName);
+
+    tex->loadImage(image);
+
+    // create a buffer to use for dynamic operations
+    std::vector<uint32> buffer;
+    buffer.resize(sFogOfWarResolution*sFogOfWarResolution);
+    memcpy(&buffer[0], image.getData(), image.getSize());
+
+    mBuffers[texturePrefix] = buffer;
 }
 
 void LocalMap::render(const float x, const float y,
@@ -249,31 +398,6 @@ void LocalMap::render(const float x, const float y,
         vp->setMaterialScheme("local_map");
 
         rtt->update();
-
-        // create "fog of war" texture
-        TexturePtr tex2 = TextureManager::getSingleton().createManual(
-                        texture + "_fog",
-                        ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
-                        TEX_TYPE_2D,
-                        xw*sFogOfWarResolution/sSize, yw*sFogOfWarResolution/sSize,
-                        0,
-                        PF_A8R8G8B8,
-                        TU_DYNAMIC_WRITE_ONLY_DISCARDABLE);
-
-        // create a buffer to use for dynamic operations
-        std::vector<uint32> buffer;
-        buffer.resize(sFogOfWarResolution*sFogOfWarResolution);
-
-        // initialize to (0, 0, 0, 1)
-        for (int p=0; p<sFogOfWarResolution*sFogOfWarResolution; ++p)
-        {
-            buffer[p] = (255 << 24);
-        }
-
-        memcpy(tex2->getBuffer()->lock(HardwareBuffer::HBL_DISCARD), &buffer[0], sFogOfWarResolution*sFogOfWarResolution*4);
-        tex2->getBuffer()->unlock();
-
-        mBuffers[texture] = buffer;
     }
 
     mRenderingManager->enableLights(true);
@@ -304,6 +428,9 @@ bool LocalMap::isPositionExplored (float nX, float nY, int x, int y, bool interi
     if (mBuffers.find(texName) == mBuffers.end())
         return false;
 
+    nX = std::max(0.f, std::min(1.f, nX));
+    nY = std::max(0.f, std::min(1.f, nY));
+
     int texU = (sFogOfWarResolution-1) * nX;
     int texV = (sFogOfWarResolution-1) * nY;
 
@@ -414,6 +541,8 @@ void LocalMap::updatePlayer (const Ogre::Vector3& position, const Ogre::Quaterni
                 }
 
                 // copy to the texture
+                // NOTE: Could be optimized later. We actually only need to update the region that changed.
+                // Not a big deal at the moment, the FoW is only 32x32 anyway.
                 memcpy(tex->getBuffer()->lock(HardwareBuffer::HBL_DISCARD), &aBuffer[0], sFogOfWarResolution*sFogOfWarResolution*4);
                 tex->getBuffer()->unlock();
             }

apps/openmw/mwrender/localmap.hpp

@@ -11,6 +11,11 @@ namespace MWWorld
     class CellStore;
 }
 
+namespace ESM
+{
+    class FogTexture;
+}
+
 namespace MWRender
 {
     class RenderingManager;
@@ -24,6 +29,11 @@ namespace MWRender
         LocalMap(OEngine::Render::OgreRenderer*, MWRender::RenderingManager* rendering);
         ~LocalMap();
 
+        /**
+         * Clear all savegame-specific data (i.e. fog of war textures)
+         */
+        void clear();
+
         /**
          * Request the local map for an exterior cell.
          * @remarks It will either be loaded from a disk cache,
@@ -54,10 +64,8 @@ namespace MWRender
         void updatePlayer (const Ogre::Vector3& position, const Ogre::Quaternion& orientation);
 
         /**
-         * Save the fog of war for the current cell to disk.
+         * Save the fog of war for this cell to its CellStore.
-         * @remarks This should be called before loading a
+         * @remarks This should be called when unloading a cell, and for all active cells prior to saving the game.
-         * new cell, as well as when the game is quit.
-         * @param current cell
          */
         void saveFogOfWar(MWWorld::CellStore* cell);
 
@@ -104,17 +112,20 @@ namespace MWRender
                     const float xw, const float yw,
                     const std::string& texture);
 
-        void saveTexture(const std::string& texname, const std::string& filename);
+        // Creates a fog of war texture and initializes it to full black
+        void createFogOfWar(const std::string& texturePrefix);
+
+        // Loads a fog of war texture from its ESM struct
+        void loadFogOfWar(const std::string& texturePrefix, ESM::FogTexture& esm); // FogTexture not const because MemoryDataStream doesn't accept it
+
+        Ogre::TexturePtr createFogOfWarTexture(const std::string& name);
 
         std::string coordStr(const int x, const int y);
 
-        // a buffer for the "fog of war" texture of the current cell.
+        // A buffer for the "fog of war" textures of the current cell.
-        // interior cells could be divided into multiple textures,
+        // Both interior and exterior maps are possibly divided into multiple textures.
-        // so we store in a map.
         std::map <std::string, std::vector<Ogre::uint32> > mBuffers;
 
-        void deleteBuffers();
-
         bool mInterior;
         int mCellX, mCellY;
         Ogre::AxisAlignedBox mBounds;

apps/openmw/mwrender/renderingmanager.cpp

@@ -223,6 +223,7 @@ OEngine::Render::Fader* RenderingManager::getFader()
 
 void RenderingManager::removeCell (MWWorld::CellStore *store)
 {
+    mLocalMap->saveFogOfWar(store);
     mObjects->removeCell(store);
     mActors->removeCell(store);
     mDebugging->cellRemoved(store);
@@ -671,7 +672,7 @@ void RenderingManager::requestMap(MWWorld::CellStore* cell)
         mLocalMap->requestMap(cell, mObjects->getDimensions(cell));
 }
 
-void RenderingManager::preCellChange(MWWorld::CellStore* cell)
+void RenderingManager::writeFog(MWWorld::CellStore* cell)
 {
     mLocalMap->saveFogOfWar(cell);
 }
@@ -1057,4 +1058,9 @@ void RenderingManager::spawnEffect(const std::string &model, const std::string &
     mEffectManager->addEffect(model, texture, worldPosition, scale);
 }
 
+void RenderingManager::clear()
+{
+    mLocalMap->clear();
+}
+
 } // namespace

apps/openmw/mwrender/renderingmanager.hpp

@@ -107,12 +107,15 @@ public:
     void cellAdded (MWWorld::CellStore *store);
     void waterAdded(MWWorld::CellStore *store);
 
+    /// Clear all savegame-specific data (i.e. fog of war textures)
+    void clear();
+
     void enableTerrain(bool enable);
 
     void removeWater();
 
-    void preCellChange (MWWorld::CellStore* store);
+    /// Write current fog of war for this cell to the CellStore
-    ///< this event is fired immediately before changing cell
+    void writeFog (MWWorld::CellStore* store);
 
     void addObject (const MWWorld::Ptr& ptr);
     void removeObject (const MWWorld::Ptr& ptr);

apps/openmw/mwworld/cells.cpp

@@ -78,6 +78,7 @@ void MWWorld::Cells::writeCell (ESM::ESMWriter& writer, CellStore& cell) const
     writer.startRecord (ESM::REC_CSTA);
     cellState.mId.save (writer);
     cellState.save (writer);
+    cell.writeFog(writer);
     cell.writeReferences (writer);
     writer.endRecord (ESM::REC_CSTA);
 }
@@ -319,6 +320,9 @@ bool MWWorld::Cells::readRecord (ESM::ESMReader& reader, int32_t type,
         state.load (reader);
         cellStore->loadState (state);
 
+        if (state.mHasFogOfWar)
+            cellStore->readFog(reader);
+
         if (cellStore->getState()!=CellStore::State_Loaded)
             cellStore->load (mStore, mReader);
 

apps/openmw/mwworld/cellstore.cpp

@@ -11,6 +11,7 @@
 #include <components/esm/containerstate.hpp>
 #include <components/esm/npcstate.hpp>
 #include <components/esm/creaturestate.hpp>
+#include <components/esm/fogstate.hpp>
 
 #include "../mwbase/environment.hpp"
 #include "../mwbase/world.hpp"
@@ -533,6 +534,21 @@ namespace MWWorld
             state.mWaterLevel = mWaterLevel;
 
         state.mWaterLevel = mWaterLevel;
+        state.mHasFogOfWar = (mFogState.get() ? 1 : 0);
+    }
+
+    void CellStore::writeFog(ESM::ESMWriter &writer) const
+    {
+        if (mFogState.get())
+        {
+            mFogState->save(writer, mCell->mData.mFlags & ESM::Cell::Interior);
+        }
+    }
+
+    void CellStore::readFog(ESM::ESMReader &reader)
+    {
+        mFogState.reset(new ESM::FogState());
+        mFogState->load(reader);
     }
 
     void CellStore::writeReferences (ESM::ESMWriter& writer) const
@@ -697,4 +713,14 @@ namespace MWWorld
     {
         return mPathgridGraph.aStarSearch(start, end);
     }
+
+    void CellStore::setFog(ESM::FogState *fog)
+    {
+        mFogState.reset(fog);
+    }
+
+    ESM::FogState* CellStore::getFog() const
+    {
+        return mFogState.get();
+    }
 }

apps/openmw/mwworld/cellstore.hpp

@@ -3,22 +3,28 @@
 
 #include <algorithm>
 #include <stdexcept>
+#include <boost/shared_ptr.hpp>
 
 #include "livecellref.hpp"
 #include "esmstore.hpp"
 #include "cellreflist.hpp"
 
+#include <components/esm/fogstate.hpp>
+
 #include "../mwmechanics/pathgrid.hpp"  // TODO: maybe belongs in mwworld
 
 namespace ESM
 {
     struct CellState;
+    struct FogState;
 }
 
 namespace MWWorld
 {
     class Ptr;
 
+
+
     /// \brief Mutable state of a cell
     class CellStore
     {
@@ -31,6 +37,11 @@ namespace MWWorld
 
         private:
 
+            // Even though fog actually belongs to the player and not cells,
+            // it makes sense to store it here since we need it once for each cell.
+            // Note this is NULL until the cell is explored to save some memory
+            boost::shared_ptr<ESM::FogState> mFogState;
+
             const ESM::Cell *mCell;
             State mState;
             bool mHasState;
@@ -84,6 +95,11 @@ namespace MWWorld
 
             void setWaterLevel (float level);
 
+            void setFog (ESM::FogState* fog);
+            ///< \note Takes ownership of the pointer
+
+            ESM::FogState* getFog () const;
+
             int count() const;
             ///< Return total number of references, including deleted ones.
 
@@ -134,6 +150,10 @@ namespace MWWorld
 
             void saveState (ESM::CellState& state) const;
 
+            void writeFog (ESM::ESMWriter& writer) const;
+
+            void readFog (ESM::ESMReader& reader);
+
             void writeReferences (ESM::ESMWriter& writer) const;
 
             void readReferences (ESM::ESMReader& reader, const std::map<int, int>& contentFileMap);

apps/openmw/mwworld/worldimp.cpp

@@ -231,6 +231,8 @@ namespace MWWorld
 
     void World::clear()
     {
+        mRendering->clear();
+
         mLocalScripts.clear();
         mPlayer->clear();
 
@@ -277,6 +279,14 @@ namespace MWWorld
 
     void World::write (ESM::ESMWriter& writer, Loading::Listener& progress) const
     {
+        // Active cells could have a dirty fog of war, sync it to the CellStore first
+        for (Scene::CellStoreCollection::const_iterator iter (mWorldScene->getActiveCells().begin());
+            iter!=mWorldScene->getActiveCells().end(); ++iter)
+        {
+            CellStore* cellstore = *iter;
+            mRendering->writeFog(cellstore);
+        }
+
         mCells.write (writer, progress);
         mStore.write (writer, progress);
         mGlobalVariables.write (writer, progress);

components/CMakeLists.txt

@@ -45,7 +45,7 @@ add_component_dir (esm
     loadnpc loadpgrd loadrace loadregn loadscpt loadskil loadsndg loadsoun loadspel loadsscr loadstat
     loadweap records aipackage effectlist spelllist variant variantimp loadtes3 cellref filter
     savedgame journalentry queststate locals globalscript player objectstate cellid cellstate globalmap lightstate inventorystate containerstate npcstate creaturestate dialoguestate statstate
-    npcstats creaturestats weatherstate quickkeys
+    npcstats creaturestats weatherstate quickkeys fogstate
     )
 
 add_component_dir (misc

components/esm/cellstate.cpp

@@ -8,10 +8,15 @@ void ESM::CellState::load (ESMReader &esm)
 {
     mWaterLevel = 0;
     esm.getHNOT (mWaterLevel, "WLVL");
+
+    mHasFogOfWar = false;
+    esm.getHNOT (mHasFogOfWar, "HFOW");
 }
 
 void ESM::CellState::save (ESMWriter &esm) const
 {
     if (!mId.mPaged)
         esm.writeHNT ("WLVL", mWaterLevel);
+
+    esm.writeHNT("HFOW", mHasFogOfWar);
 }

components/esm/cellstate.hpp

@@ -17,6 +17,8 @@ namespace ESM
 
         float mWaterLevel;
 
+        int mHasFogOfWar; // Do we have fog of war state (0 or 1)? (see fogstate.hpp)
+
         void load (ESMReader &esm);
         void save (ESMWriter &esm) const;
     };

components/esm/fogstate.cpp

@@ -0,0 +1,40 @@
+#include "fogstate.hpp"
+
+#include "esmreader.hpp"
+#include "esmwriter.hpp"
+
+void ESM::FogState::load (ESMReader &esm)
+{
+    esm.getHNOT(mBounds, "BOUN");
+    esm.getHNOT(mNorthMarkerAngle, "ANGL");
+    while (esm.isNextSub("FTEX"))
+    {
+        esm.getSubHeader();
+        FogTexture tex;
+
+        esm.getT(tex.mX);
+        esm.getT(tex.mY);
+
+        size_t imageSize = esm.getSubSize()-sizeof(int)*2;
+        tex.mImageData.resize(imageSize);
+        esm.getExact(&tex.mImageData[0], imageSize);
+        mFogTextures.push_back(tex);
+    }
+}
+
+void ESM::FogState::save (ESMWriter &esm, bool interiorCell) const
+{
+    if (interiorCell)
+    {
+        esm.writeHNT("BOUN", mBounds);
+        esm.writeHNT("ANGL", mNorthMarkerAngle);
+    }
+    for (std::vector<FogTexture>::const_iterator it = mFogTextures.begin(); it != mFogTextures.end(); ++it)
+    {
+        esm.startSubRecord("FTEX");
+        esm.writeT(it->mX);
+        esm.writeT(it->mY);
+        esm.write(&it->mImageData[0], it->mImageData.size());
+        esm.endRecord("FTEX");
+    }
+}

components/esm/fogstate.hpp

@@ -0,0 +1,38 @@
+#ifndef OPENMW_ESM_FOGSTATE_H
+#define OPENMW_ESM_FOGSTATE_H
+
+#include <vector>
+
+namespace ESM
+{
+    class ESMReader;
+    class ESMWriter;
+
+    struct FogTexture
+    {
+        int mX, mY; // Only used for interior cells
+        std::vector<char> mImageData;
+    };
+
+    // format 0, saved games only
+    // Fog of war state
+    struct FogState
+    {
+        // Only used for interior cells
+        float mNorthMarkerAngle;
+        struct Bounds
+        {
+            float mMinX;
+            float mMinY;
+            float mMaxX;
+            float mMaxY;
+        } mBounds;
+
+        std::vector<FogTexture> mFogTextures;
+
+        void load (ESMReader &esm);
+        void save (ESMWriter &esm, bool interiorCell) const;
+    };
+}
+
+#endif