Make followers keep a distance dependant on the fattest party member

apps/openmw/mwbase/mechanicsmanager.hpp

@@ -199,6 +199,7 @@ namespace MWBase
             virtual std::list<MWWorld::Ptr> getActorsSidingWith(const MWWorld::Ptr& actor) = 0;
             virtual std::list<MWWorld::Ptr> getActorsFollowing(const MWWorld::Ptr& actor) = 0;
             virtual std::list<int> getActorsFollowingIndices(const MWWorld::Ptr& actor) = 0;
+            virtual std::map<int, MWWorld::Ptr> getActorsFollowingByIndex(const MWWorld::Ptr& actor) = 0;
 
             ///Returns a list of actors who are fighting the given actor within the fAlarmDistance
             /** ie AiCombat is active and the target is the actor **/

apps/openmw/mwmechanics/actors.cpp

@@ -142,6 +142,29 @@ void getRestorationPerHourOfSleep (const MWWorld::Ptr& ptr, float& health, float
     magicka = fRestMagicMult * stats.getAttribute(ESM::Attribute::Intelligence).getModified();
 }
 
+template<class T>
+void forEachFollowingPackage(MWMechanics::Actors::PtrActorMap& actors, const MWWorld::Ptr& actor, const MWWorld::Ptr& player, T&& func)
+{
+    for(auto& iter : actors)
+    {
+        const MWWorld::Ptr &iteratedActor = iter.first;
+        if (iteratedActor == player || iteratedActor == actor)
+            continue;
+
+        const MWMechanics::CreatureStats &stats = iteratedActor.getClass().getCreatureStats(iteratedActor);
+        if (stats.isDead())
+            continue;
+
+        // An actor counts as following if AiFollow is the current AiPackage,
+        // or there are only Combat and Wander packages before the AiFollow package
+        for (const auto& package : stats.getAiSequence())
+        {
+            if(!func(iter, package))
+                break;
+        }
+    }
+}
+
 }
 
 namespace MWMechanics
@@ -2512,26 +2535,14 @@ namespace MWMechanics
     std::list<MWWorld::Ptr> Actors::getActorsFollowing(const MWWorld::Ptr& actor)
     {
         std::list<MWWorld::Ptr> list;
-        for(PtrActorMap::iterator iter(mActors.begin());iter != mActors.end();++iter)
-        {
-            const MWWorld::Ptr &iteratedActor = iter->first;
-            if (iteratedActor == getPlayer() || iteratedActor == actor)
-                continue;
-
-            const CreatureStats &stats = iteratedActor.getClass().getCreatureStats(iteratedActor);
-            if (stats.isDead())
-                continue;
-
-            // An actor counts as following if AiFollow is the current AiPackage,
-            // or there are only Combat and Wander packages before the AiFollow package
-            for (const auto& package : stats.getAiSequence())
-            {
-                if (package->followTargetThroughDoors() && package->getTarget() == actor)
-                    list.push_back(iteratedActor);
-                else if (package->getTypeId() != AiPackageTypeId::Combat && package->getTypeId() != AiPackageTypeId::Wander)
-                    break;
-            }
-        }
+        forEachFollowingPackage(mActors, actor, getPlayer(), [&] (auto& iter, const std::unique_ptr<AiPackage>& package)
+        {
+            if (package->followTargetThroughDoors() && package->getTarget() == actor)
+                list.push_back(iter.first);
+            else if (package->getTypeId() != AiPackageTypeId::Combat && package->getTypeId() != AiPackageTypeId::Wander)
+                return false;
+            return true;
+        });
         return list;
     }
 
@@ -2575,32 +2586,38 @@ namespace MWMechanics
     std::list<int> Actors::getActorsFollowingIndices(const MWWorld::Ptr &actor)
     {
         std::list<int> list;
-        for(PtrActorMap::iterator iter(mActors.begin());iter != mActors.end();++iter)
+        forEachFollowingPackage(mActors, actor, getPlayer(), [&] (auto& iter, const std::unique_ptr<AiPackage>& package)
         {
-            const MWWorld::Ptr &iteratedActor = iter->first;
-            if (iteratedActor == getPlayer() || iteratedActor == actor)
-                continue;
-
-            const CreatureStats &stats = iteratedActor.getClass().getCreatureStats(iteratedActor);
-            if (stats.isDead())
-                continue;
-
-            // An actor counts as following if AiFollow is the current AiPackage,
-            // or there are only Combat and Wander packages before the AiFollow package
-            for (const auto& package : stats.getAiSequence())
+            if (package->followTargetThroughDoors() && package->getTarget() == actor)
             {
-                if (package->followTargetThroughDoors() && package->getTarget() == actor)
-                {
-                    list.push_back(static_cast<const AiFollow*>(package.get())->getFollowIndex());
-                    break;
-                }
-                else if (package->getTypeId() != AiPackageTypeId::Combat && package->getTypeId() != AiPackageTypeId::Wander)
-                    break;
+                list.push_back(static_cast<const AiFollow*>(package.get())->getFollowIndex());
+                return false;
             }
-        }
+            else if (package->getTypeId() != AiPackageTypeId::Combat && package->getTypeId() != AiPackageTypeId::Wander)
+                return false;
+            return true;
+        });
         return list;
     }
 
+    std::map<int, MWWorld::Ptr> Actors::getActorsFollowingByIndex(const MWWorld::Ptr &actor)
+    {
+        std::map<int, MWWorld::Ptr> map;
+        forEachFollowingPackage(mActors, actor, getPlayer(), [&] (auto& iter, const std::unique_ptr<AiPackage>& package)
+        {
+            if (package->followTargetThroughDoors() && package->getTarget() == actor)
+            {
+                int index = static_cast<const AiFollow*>(package.get())->getFollowIndex();
+                map[index] = iter.first;
+                return false;
+            }
+            else if (package->getTypeId() != AiPackageTypeId::Combat && package->getTypeId() != AiPackageTypeId::Wander)
+                return false;
+            return true;
+        });
+        return map;
+    }
+
     std::list<MWWorld::Ptr> Actors::getActorsFighting(const MWWorld::Ptr& actor) {
         std::list<MWWorld::Ptr> list;
         std::vector<MWWorld::Ptr> neighbors;

apps/openmw/mwmechanics/actors.hpp

@@ -181,6 +181,7 @@ namespace MWMechanics
 
             /// Get the list of AiFollow::mFollowIndex for all actors following this target
             std::list<int> getActorsFollowingIndices(const MWWorld::Ptr& actor);
+            std::map<int, MWWorld::Ptr> getActorsFollowingByIndex(const MWWorld::Ptr& actor);
 
             ///Returns the list of actors which are fighting the given actor
             /**ie AiCombat is active and the target is the actor **/

apps/openmw/mwmechanics/aifollow.cpp

@@ -113,24 +113,23 @@ bool AiFollow::execute (const MWWorld::Ptr& actor, CharacterController& characte
     if (!mActive)
         return false;
 
-    // The distances below are approximations based on observations of the original engine.
-    // If only one actor is following the target, it uses 186.
-    // If there are multiple actors following the same target, they form a group with each group member at 313 + (130 * i) distance to the target.
-
-    short followDistance = 186;
-    std::list<int> followers = MWBase::Environment::get().getMechanicsManager()->getActorsFollowingIndices(target);
-    if (followers.size() >= 2)
+    // In the original engine the first follower stays closer to the player than any subsequent followers.
+    // Followers beyond the first usually attempt to stand inside each other.
+    osg::Vec3f::value_type floatingDistance = 0;
+    auto followers = MWBase::Environment::get().getMechanicsManager()->getActorsFollowingByIndex(target);
+    if (followers.size() >= 2 && followers.cbegin()->first != mFollowIndex)
     {
-        followDistance = 313;
-        short i = 0;
-        followers.sort();
-        for (int followIndex : followers)
+        osg::Vec3f::value_type maxSize = 0;
+        for(auto& follower : followers)
         {
-            if (followIndex == mFollowIndex)
-                followDistance += 130 * i;
-            ++i;
+            auto halfExtent = MWBase::Environment::get().getWorld()->getHalfExtents(follower.second).y();
+            if(halfExtent > floatingDistance)
+                floatingDistance = halfExtent;
         }
     }
+    floatingDistance += MWBase::Environment::get().getWorld()->getHalfExtents(target).y();
+    floatingDistance += MWBase::Environment::get().getWorld()->getHalfExtents(actor).y() * 2;
+    short followDistance = static_cast<short>(floatingDistance);
 
     if (!mAlwaysFollow) //Update if you only follow for a bit
     {

apps/openmw/mwmechanics/mechanicsmanagerimp.cpp

@@ -1654,6 +1654,11 @@ namespace MWMechanics
         return mActors.getActorsFollowingIndices(actor);
     }
 
+    std::map<int, MWWorld::Ptr> MechanicsManager::getActorsFollowingByIndex(const MWWorld::Ptr& actor)
+    {
+        return mActors.getActorsFollowingByIndex(actor);
+    }
+
     std::list<MWWorld::Ptr> MechanicsManager::getActorsFighting(const MWWorld::Ptr& actor) {
         return mActors.getActorsFighting(actor);
     }

apps/openmw/mwmechanics/mechanicsmanagerimp.hpp

@@ -150,6 +150,7 @@ namespace MWMechanics
             std::list<MWWorld::Ptr> getActorsSidingWith(const MWWorld::Ptr& actor) override;
             std::list<MWWorld::Ptr> getActorsFollowing(const MWWorld::Ptr& actor) override;
             std::list<int> getActorsFollowingIndices(const MWWorld::Ptr& actor) override;
+            std::map<int, MWWorld::Ptr> getActorsFollowingByIndex(const MWWorld::Ptr& actor) override;
 
             std::list<MWWorld::Ptr> getActorsFighting(const MWWorld::Ptr& actor) override;
             std::list<MWWorld::Ptr> getEnemiesNearby(const MWWorld::Ptr& actor) override;