Core/Movement: Replace old TargetedMovementGenerator into ChaseMovementGenerator and FollowMovementGenerator, full rewrite for both.

- Chase to angle is now functional. Pets use this to chase behind the target. Closes #19925.
- Chase to arbitrary range interval works. Not used anywhere, but you can technically make hunter-like mobs.
- Pets now follow the hunter cleanly and without stutter stepping. Also fix some other things. Closes #8924.

1 files changed, 18 insertions, 37 deletions

diff --git a/src/server/game/Movement/MotionMaster.cpp b/src/server/game/Movement/MotionMaster.cpp
index cb00f455959..62396a0a315 100644
--- a/src/server/game/Movement/MotionMaster.cpp
+++ b/src/server/game/Movement/MotionMaster.cpp
@@ -17,12 +17,14 @@
  */
 
 #include "MotionMaster.h"
+#include "ChaseMovementGenerator.h"
 #include "ConfusedMovementGenerator.h"
 #include "Creature.h"
 #include "CreatureAISelector.h"
 #include "DBCStores.h"
 #include "FleeingMovementGenerator.h"
 #include "FlightPathMovementGenerator.h"
+#include "FollowMovementGenerator.h"
 #include "FormationMovementGenerator.h"
 #include "HomeMovementGenerator.h"
 #include "IdleMovementGenerator.h"
@@ -36,7 +38,6 @@
 #include "RandomMovementGenerator.h"
 #include "ScriptSystem.h"
 #include "SplineChainMovementGenerator.h"
-#include "TargetedMovementGenerator.h"
 #include "Unit.h"
 #include "WaypointDefines.h"
 #include "WaypointMovementGenerator.h"
@@ -219,7 +220,7 @@ void MotionMaster::MoveTargetedHome()
         if (target)
         {
             TC_LOG_DEBUG("misc", "Following %s (GUID: %u).", target->GetTypeId() == TYPEID_PLAYER ? "player" : "creature", target->GetTypeId() == TYPEID_PLAYER ? target->GetGUID().GetCounter() : ((Creature*)target)->GetSpawnId());
-            Mutate(new FollowMovementGenerator<Creature>(target, PET_FOLLOW_DIST, PET_FOLLOW_ANGLE), MOTION_SLOT_ACTIVE);
+            Mutate(new FollowMovementGenerator(target, PET_FOLLOW_DIST, PET_FOLLOW_ANGLE), MOTION_SLOT_ACTIVE);
         }
     }
     else
@@ -237,53 +238,33 @@ void MotionMaster::MoveRandom(float spawndist)
     }
 }
 
-void MotionMaster::MoveFollow(Unit* target, float dist, float angle, MovementSlot slot)
+void MotionMaster::MoveFollow(Unit* target, float dist, ChaseAngle angle, MovementSlot slot)
 {
     // ignore movement request if target not exist
     if (!target || target == _owner)
         return;
 
-    //_owner->AddUnitState(UNIT_STATE_FOLLOW);
-    if (_owner->GetTypeId() == TYPEID_PLAYER)
-    {
-        TC_LOG_DEBUG("misc", "Player (GUID: %u) follows %s (GUID: %u).", _owner->GetGUID().GetCounter(),
-            target->GetTypeId() == TYPEID_PLAYER ? "player" : "creature",
-            target->GetTypeId() == TYPEID_PLAYER ? target->GetGUID().GetCounter() : target->ToCreature()->GetSpawnId());
-        Mutate(new FollowMovementGenerator<Player>(target, dist, angle), slot);
-    }
-    else
-    {
-        TC_LOG_DEBUG("misc", "Creature (Entry: %u GUID: %u) follows %s (GUID: %u).",
-            _owner->GetEntry(), _owner->GetGUID().GetCounter(),
-            target->GetTypeId() == TYPEID_PLAYER ? "player" : "creature",
-            target->GetTypeId() == TYPEID_PLAYER ? target->GetGUID().GetCounter() : target->ToCreature()->GetSpawnId());
-        Mutate(new FollowMovementGenerator<Creature>(target, dist, angle), slot);
-    }
+    TC_LOG_DEBUG("misc", "%s (Entry: %u, GUID: %u) follows %s (Entry %u, GUID: %u).",
+        _owner->GetTypeId() == TYPEID_PLAYER ? "Player" : "Creature",
+        _owner->GetEntry(), _owner->GetGUID().GetCounter(),
+        target->GetTypeId() == TYPEID_PLAYER ? "player" : "creature",
+        target->GetEntry(), target->GetGUID().GetCounter());
+
+    Mutate(new FollowMovementGenerator(target, dist, angle), slot);
 }
 
-void MotionMaster::MoveChase(Unit* target, float dist, float angle)
+void MotionMaster::MoveChase(Unit* target, Optional<ChaseRange> dist, Optional<ChaseAngle> angle)
 {
     // ignore movement request if target not exist
     if (!target || target == _owner)
         return;
 
-    //_owner->ClearUnitState(UNIT_STATE_FOLLOW);
-    if (_owner->GetTypeId() == TYPEID_PLAYER)
-    {
-        TC_LOG_DEBUG("misc", "Player (GUID: %u) chase to %s (GUID: %u)",
-            _owner->GetGUID().GetCounter(),
-            target->GetTypeId() == TYPEID_PLAYER ? "player" : "creature",
-            target->GetTypeId() == TYPEID_PLAYER ? target->GetGUID().GetCounter() : target->ToCreature()->GetSpawnId());
-        Mutate(new ChaseMovementGenerator<Player>(target, dist, angle), MOTION_SLOT_ACTIVE);
-    }
-    else
-    {
-        TC_LOG_DEBUG("misc", "Creature (Entry: %u GUID: %u) chase to %s (GUID: %u)",
-            _owner->GetEntry(), _owner->GetGUID().GetCounter(),
-            target->GetTypeId() == TYPEID_PLAYER ? "player" : "creature",
-            target->GetTypeId() == TYPEID_PLAYER ? target->GetGUID().GetCounter() : target->ToCreature()->GetSpawnId());
-        Mutate(new ChaseMovementGenerator<Creature>(target, dist, angle), MOTION_SLOT_ACTIVE);
-    }
+    TC_LOG_DEBUG("misc", "%s (Entry: %u, GUID: %u) chase to %s (Entry: %u, GUID: %u)",
+        _owner->GetTypeId() == TYPEID_PLAYER ? "Player" : "Creature",
+        _owner->GetEntry(), _owner->GetGUID().GetCounter(),
+        target->GetTypeId() == TYPEID_PLAYER ? "player" : "creature",
+        target->GetEntry(), target->GetGUID().GetCounter());
+    Mutate(new ChaseMovementGenerator(target, dist, angle), MOTION_SLOT_ACTIVE);
 }
 
 void MotionMaster::MoveConfused()