From 023c87b21595353b98edce6176b38f8dca52f288 Mon Sep 17 00:00:00 2001
From: scrawl <scrawl@baseoftrash.de>
Date: Sun, 7 Feb 2016 05:13:46 -0800
Subject: [PATCH] Preload cell when the player goes near a teleport door. It
 works!

---
 apps/openmw/mwworld/cellpreloader.cpp |  2 +
 apps/openmw/mwworld/scene.cpp         | 58 +++++++++++++++++++++++++++
 apps/openmw/mwworld/scene.hpp         |  3 ++
 3 files changed, 63 insertions(+)

diff --git a/apps/openmw/mwworld/cellpreloader.cpp b/apps/openmw/mwworld/cellpreloader.cpp
index 16bf920bb..f1366a8b2 100644
--- a/apps/openmw/mwworld/cellpreloader.cpp
+++ b/apps/openmw/mwworld/cellpreloader.cpp
@@ -66,6 +66,7 @@ namespace MWWorld
         /// Preload work to be called from the worker thread.
         virtual void doWork()
         {
+            osg::Timer preloadTimer;
             for (MeshList::const_iterator it = mMeshes.begin(); it != mMeshes.end(); ++it)
             {
                 try
@@ -81,6 +82,7 @@ namespace MWWorld
                     // error will be shown when visiting the cell
                 }
             }
+            std::cout << "preloaded " << mPreloadedNodes.size() << " nodes in " << preloadTimer.time_m() << std::endl;
         }
 
     private:
diff --git a/apps/openmw/mwworld/scene.cpp b/apps/openmw/mwworld/scene.cpp
index 70a461b5b..912a39e7c 100644
--- a/apps/openmw/mwworld/scene.cpp
+++ b/apps/openmw/mwworld/scene.cpp
@@ -193,6 +193,13 @@ namespace MWWorld
 
     void Scene::update (float duration, bool paused)
     {
+        mPreloadTimer += duration;
+        if (mPreloadTimer > 1.f)
+        {
+            preloadCells();
+            mPreloadTimer = 0.f;
+        }
+
         mRendering.update (duration, paused);
     }
 
@@ -440,6 +447,7 @@ namespace MWWorld
 
     Scene::Scene (MWRender::RenderingManager& rendering, MWPhysics::PhysicsSystem *physics)
     : mCurrentCell (0), mCellChanged (false), mPhysics(physics), mRendering(rendering)
+    , mPreloadTimer(0.f)
     {
         mPreloader.reset(new CellPreloader(rendering.getResourceSystem(), physics->getShapeManager()));
     }
@@ -603,4 +611,54 @@ namespace MWWorld
 
         return Ptr();
     }
+
+    void Scene::preloadCells()
+    {
+        std::vector<MWWorld::ConstPtr> teleportDoors;
+        for (CellStoreCollection::const_iterator iter (mActiveCells.begin());
+            iter!=mActiveCells.end(); ++iter)
+        {
+            const MWWorld::CellStore* cellStore = *iter;
+            typedef MWWorld::CellRefList<ESM::Door>::List DoorList;
+            const DoorList &doors = cellStore->getReadOnlyDoors().mList;
+            for (DoorList::const_iterator doorIt = doors.begin(); doorIt != doors.end(); ++doorIt)
+            {
+                if (!doorIt->mRef.getTeleport()) {
+                    continue;
+                }
+                teleportDoors.push_back(MWWorld::ConstPtr(&*doorIt, cellStore));
+            }
+        }
+
+        const MWWorld::ConstPtr player = MWBase::Environment::get().getWorld()->getPlayerPtr();
+        const float preloadDist = 500.f;
+
+        for (std::vector<MWWorld::ConstPtr>::iterator it = teleportDoors.begin(); it != teleportDoors.end(); ++it)
+        {
+            const MWWorld::ConstPtr& door = *it;
+            float sqrDistToPlayer = (player.getRefData().getPosition().asVec3() - door.getRefData().getPosition().asVec3()).length2();
+
+            if (sqrDistToPlayer < preloadDist*preloadDist)
+            {
+                MWWorld::CellStore* targetCell = NULL;
+                try
+                {
+                    if (!door.getCellRef().getDestCell().empty())
+                        targetCell = MWBase::Environment::get().getWorld()->getInterior(door.getCellRef().getDestCell());
+                    else
+                    {
+                        int x,y;
+                        MWBase::Environment::get().getWorld()->positionToIndex (door.getCellRef().getDoorDest().pos[0], door.getCellRef().getDoorDest().pos[1], x, y);
+                        targetCell = MWBase::Environment::get().getWorld()->getExterior(x, y);
+                    }
+                }
+                catch (std::exception& e)
+                {
+                    // ignore error for now, would spam the log too much
+                }
+                if (targetCell)
+                    mPreloader->preload(targetCell, mRendering.getReferenceTime());
+            }
+        }
+    }
 }
diff --git a/apps/openmw/mwworld/scene.hpp b/apps/openmw/mwworld/scene.hpp
index b428d0ddd..4ac0d0666 100644
--- a/apps/openmw/mwworld/scene.hpp
+++ b/apps/openmw/mwworld/scene.hpp
@@ -58,6 +58,7 @@ namespace MWWorld
             MWPhysics::PhysicsSystem *mPhysics;
             MWRender::RenderingManager& mRendering;
             std::auto_ptr<CellPreloader> mPreloader;
+            float mPreloadTimer;
 
             void insertCell (CellStore &cell, bool rescale, Loading::Listener* loadingListener);
 
@@ -112,6 +113,8 @@ namespace MWWorld
             bool isCellActive(const CellStore &cell);
 
             Ptr searchPtrViaActorId (int actorId);
+
+            void preloadCells();
     };
 }