Core/Misc: Add new function for selection nearest player in given distance

src/server/game/Entities/Creature/Creature.cpp

@@ -1817,6 +1817,17 @@ Unit* Creature::SelectNearestTargetInAttackDistance(float dist) const
     return target;
 }
 
+Player* Creature::SelectNearestPlayer(float distance) const
+{
+    Player* target = NULL;
+
+    Trinity::NearestPlayerInObjectRangeCheck checker(this, distance);
+    Trinity::PlayerLastSearcher<Trinity::NearestPlayerInObjectRangeCheck> searcher(this, target, checker);
+    VisitNearbyObject(distance, searcher);
+
+    return target;
+}
+
 void Creature::SendAIReaction(AiReaction reactionType)
 {
     WorldPacket data(SMSG_AI_REACTION, 12);

src/server/game/Entities/Creature/Creature.h

@@ -584,6 +584,7 @@ class Creature : public Unit, public GridObject<Creature>
 
         Unit* SelectNearestTarget(float dist = 0) const;
         Unit* SelectNearestTargetInAttackDistance(float dist = 0) const;
+        Player* SelectNearestPlayer(float distance = 0) const;
 
         void DoFleeToGetAssistance();
         void CallForHelp(float fRadius);

src/server/game/Grids/Notifiers/GridNotifiers.h

@@ -449,6 +449,22 @@ namespace Trinity
         template<class NOT_INTERESTED> void Visit(GridRefManager<NOT_INTERESTED> &) {}
     };
 
+    template<class Check>
+    struct PlayerLastSearcher
+    {
+        uint32 i_phaseMask;
+        Player* &i_object;
+        Check& i_check;
+
+        PlayerLastSearcher(WorldObject const* searcher, Player*& result, Check& check) : i_phaseMask(searcher->GetPhaseMask()), i_object(result), i_check(check)
+        {
+        }
+
+        void Visit(PlayerMapType& m);
+
+        template<class NOT_INTERESTED> void Visit(GridRefManager<NOT_INTERESTED> &) {}
+    };
+
     template<class Do>
     struct PlayerWorker
     {
@@ -1144,6 +1160,30 @@ namespace Trinity
         float i_range;
     };
 
+    class NearestPlayerInObjectRangeCheck
+    {
+        public:
+            NearestPlayerInObjectRangeCheck(WorldObject const* obj, float range) : i_obj(obj), i_range(range)
+            {
+            }
+
+            bool operator()(Player* u)
+            {
+                if (u->isAlive() && i_obj->IsWithinDistInMap(u, i_range))
+                {
+                    i_range = i_obj->GetDistance(u);
+                    return true;
+                }
+
+                return false;
+            }
+        private:
+            WorldObject const* i_obj;
+            float i_range;
+
+            NearestPlayerInObjectRangeCheck(NearestPlayerInObjectRangeCheck const&);
+    };
+
     class AllFriendlyCreaturesInGrid
     {
     public:

src/server/game/Grids/Notifiers/GridNotifiersImpl.h

@@ -398,6 +398,19 @@ void Trinity::PlayerSearcher<Check>::Visit(PlayerMapType &m)
     }
 }
 
+template<class Check>
+void Trinity::PlayerLastSearcher<Check>::Visit(PlayerMapType& m)
+{
+    for (PlayerMapType::iterator itr = m.begin(); itr != m.end(); ++itr)
+    {
+        if (!itr->getSource()->InSamePhase(i_phaseMask))
+            continue;
+
+        if (i_check(itr->getSource()))
+            i_object = itr->getSource();
+    }
+}
+
 template<class Builder>
 void Trinity::LocalizedPacketDo<Builder>::operator()(Player* p)
 {