Eversong: Implement hatchling movement

sql/scriptdev2/scriptdev2.sql

@@ -735,6 +735,7 @@ UPDATE creature_template SET ScriptName='npc_kelerun_bloodmourn' WHERE entry=178
 UPDATE gameobject_template SET ScriptName='go_harbinger_second_trial' WHERE entry=182052;
 UPDATE creature_template SET ScriptName='npc_apprentice_mirveda' WHERE entry=15402;
 UPDATE creature_template SET ScriptName='npc_infused_crystal' WHERE entry=16364;
+UPDATE creature_template SET ScriptName='npc_hatchling_movement' WHERE entry IN(21055,21063,21064);
 
 /* FELWOOD */
 UPDATE creature_template SET ScriptName='npc_kitten' WHERE entry=9937;

src/game/AI/ScriptDevAI/scripts/eastern_kingdoms/eversong_woods.cpp

@@ -481,6 +481,32 @@ UnitAI* GetAI_npc_infused_crystalAI(Creature* pCreature)
     return new npc_infused_crystalAI(pCreature);
 }
 
+struct HatchlingMovementAI : public ScriptedAI
+{
+    HatchlingMovementAI(Creature* creature) : ScriptedAI(creature)
+    {
+        AddCustomAction(1, 1200u, [&]()
+        {
+            PickNewPoint();
+        }, TIMER_COMBAT_OOC);
+    }
+
+    void MovementInform(uint32 movementType, uint32 data) override
+    {
+        if (movementType == POINT_MOTION_TYPE && data == 1)
+            ResetTimer(1, 1200u); // exact delay after each movement
+    }
+
+    void PickNewPoint()
+    {
+        Position pos = m_creature->GetRespawnPosition();
+        float angle = rand_norm_f() * 2 * M_PI_F;
+        float range = rand_norm_f() * 2.f;
+        m_creature->MovePositionToFirstCollision(pos, range, angle);
+        m_creature->GetMotionMaster()->MovePoint(1, pos);
+    }
+};
+
 void AddSC_eversong_woods()
 {
     Script* pNewScript = new Script;
@@ -504,4 +530,9 @@ void AddSC_eversong_woods()
     pNewScript->Name = "npc_infused_crystal";
     pNewScript->GetAI = &GetAI_npc_infused_crystalAI;
     pNewScript->RegisterSelf();
+
+    pNewScript = new Script;
+    pNewScript->Name = "npc_hatchling_movement";
+    pNewScript->GetAI = &GetNewAIInstance<HatchlingMovementAI>;
+    pNewScript->RegisterSelf();
 }