Attempt to create new command for EventAI and db_script, which can be used together with FollowerAI, and separate from it.

doc/EventAI.txt

@@ -154,7 +154,7 @@ For all ACTION_T_RANDOM Actions, When a Particular Param is selected for the Eve
 46   ACTION_T_SET_THROW_MASK                EventTypeMask                   Marks for which AIEvents the npc will throw AIEvents on its own.
 47   ACTION_T_SET_STAND_STATE               StandState                      Set the unit stand state (Param1) of the current creature.
 48   ACTION_T_CHANGE_MOVEMENT               MovementType, WanderDistance    Change the unit movement type (Param1). If the movement type is Random Movement (1), the WanderDistance (Param2) must be provided.
-
+49   ACTION_T_FOLLOW_TARGET                 Distance, Angle, Target         Add the unit follow movement type on target.
 * = Use -1 where the param is expected to do nothing. Random constant is generated for each event, so if you have a random yell and a random sound, they will be linked up with each other (ie. param2 with param2).
 
 
@@ -916,6 +916,12 @@ Parameter 1: StandState - Stand state id to be used by the creature as defined i
 Parameter 1: MovementType   - Movement type id to be used by the creature. Can be 0 = Idle, 1 = Random, 2 = Waypoint.
 Parameter 2: WanderDistance - Wander distance to be used in case the movement type is 1 (Random).
 
+------------------------------
+49 = ACTION_T_FOLLOW_TARGET:
+------------------------------
+Parameter 1: Distance - The distance at which the creature will follow on target.
+Parameter 2: Angle - The angle at which the creature will follow target.
+Parameter 3: Target - Preferably ACTION_INVOKER and EVENT_SENDER, but can use any other except TARGET_SELF.
 =========================================
 Target Types
 =========================================

doc/script_commands.txt

@@ -319,3 +319,7 @@ Where "A  ->  B" means that the command is executed from A with B as target.
                                             * datalong = mailTemplateId
                                             * datalong2: AlternativeSenderEntry. Use as sender-Entry of the sent mail
                                             * dataint1: Delay (>= 0) in Seconds
+
+39 SCRIPT_COMMAND_FOLLOW                    Move Follow resultingSource = Creature, resultingTarget = Unit
+                                            * datalong = distance
+                                            * datalong2 = angle

src/game/CreatureEventAI.cpp

@@ -1019,6 +1019,24 @@ void CreatureEventAI::ProcessAction(CreatureEventAI_Action const& action, uint32
             }
             break;
         }
+        case ACTION_T_FOLLOW_TARGET:
+            m_followDistance = (float)action.follow_movement.distance;
+            m_followAngle = action.follow_movement.angle.angle;
+            Unit* target = GetTargetByType(action.follow_movement, pActionInvoker, pAIEventSender, reportTargetError);
+            if (!target)
+            {
+                if (reportTargetError)
+                    sLog.outErrorEventAI("NULL target for ACTION_T_FOLLOW_TARGET creature entry %u follow target %u", m_creature->GetEntry(), action.follow_movement);
+                return;
+            }
+                if (m_creature->GetMotionMaster()->GetCurrentMovementGeneratorType() == WAYPOINT_MOTION_TYPE)
+                {
+                    // Drop current movement gen
+                    m_creature->GetMotionMaster()->Clear;
+                    m_creature->GetMotionMaster()->MoveFollow(target, m_followDistance, m_followAngle);
+                }
+            }
+            break;
     }
 }
 

src/game/CreatureEventAI.h

@@ -120,6 +120,7 @@ enum EventAI_ActionType
     ACTION_T_SET_THROW_MASK             = 46,               // EventTypeMask, unused, unused
     ACTION_T_SET_STAND_STATE            = 47,               // StandState, unused, unused
     ACTION_T_CHANGE_MOVEMENT            = 48,               // MovementType, WanderDistance, unused
+    ACTION_T_FOLLOW_TARGET              = 49,               // Distance, Angle, Target.
 
     ACTION_T_END,
 };
@@ -414,6 +415,13 @@ struct CreatureEventAI_Action
             uint32 wanderDistance;
             uint32 unused1;
         } changeMovement;
+        // ACTION_T_FOLLOW_TARGET                           = 49
+        struct
+        {
+            uint32 distance;
+            uint32 angle;
+            uint32 target;
+        } follow_movement;
         // RAW
         struct
         {

src/game/CreatureEventAIMgr.cpp

@@ -881,7 +881,12 @@ void CreatureEventAIMgr::LoadCreatureEventAI_Scripts()
                             continue;
                         }
                         break;
-
+                    case ACTION_T_FOLLOW_TARGET:
+                        if (action.follow_movement == TARGET_T_SELF)
+                        {
+                            sLog.outErrorEventAI("Event %u Action %u uses invalid target_type %u.", i, j + 1, action.follow_movement.follow);
+                            continue;
+                        }
                     default:
                         sLog.outErrorEventAI("Event %u Action %u have currently not checked at load action type (%u). Need check code update?", i, j + 1, temp.action[j].type);
                         break;

src/game/ScriptMgr.cpp

@@ -738,6 +738,8 @@ void ScriptMgr::LoadScripts(ScriptMapMapName& scripts, const char* tablename)
                 sLog.outErrorDb("Table `%s` unknown command %u, skipping.", tablename, tmp.command);
                 continue;
             }
+            case SCRIPT_COMMAND_FOLLOW:                 // 39
+                break;
         }
 
         if (scripts.second.find(tmp.id) == scripts.second.end())
@@ -1962,6 +1964,15 @@ bool ScriptAction::HandleScriptStep()
         default:
             sLog.outErrorDb(" DB-SCRIPTS: Process table `%s` id %u, command %u unknown command used.", m_table, m_script->id, m_script->command);
             break;
+        case SCRIPT_COMMAND_FOLLOW:                   // 39
+        {
+            if (LogIfNotCreature(pSource))
+                return false;
+            if (LogIfNotUnit(pTarget))
+                return false;
+            ((Creature*)pSource)->GetMotionMaster()->MoveFollow(pTarget, distance, angle);
+            break;
+        }
     }
 
     return false;

src/game/ScriptMgr.h

@@ -117,6 +117,9 @@ enum ScriptCommand                                          // resSource, resTar
                                                             // datalong: Send mailTemplateId from resSource (if provided) to player resTarget
                                                             // datalong2: AlternativeSenderEntry. Use as sender-Entry
                                                             // dataint1: Delay (>= 0) in Seconds
+    SCRIPT_COMMAND_FOLLOW                   = 39,           // resSource Creature, resTarget Creature/Player. Move Follow towards Target.
+                                                            // datalong = distance
+                                                            // datalong2 = angle
 };
 
 #define MAX_TEXT_ID 4                                       // used for SCRIPT_COMMAND_TALK, SCRIPT_COMMAND_EMOTE, SCRIPT_COMMAND_CAST_SPELL, SCRIPT_COMMAND_TERMINATE_SCRIPT
@@ -363,6 +366,12 @@ struct ScriptInfo
             uint32 mailTemplateId;                          // datalong
             uint32 altSender;                               // datalong2;
         } sendMail;
+
+        struct                                              // SCRIPT_COMMAND_FOLLOW (39)
+        {
+            uint32 Distance;                                //datalong
+            uint32 Angle;                                   //datalong2;
+        } moveFollow;
 
         struct
         {