refactor(Core/Unit): minor changes for the combat system (#11904)

Cherry-pick from TC: https://github.com/TrinityCore/TrinityCore/pull/19966

Co-authored-by: Treeston <treeston.nmoc@gmail.com>

11 files changed, 39 insertions, 42 deletions

diff --git a/src/server/game/AI/CreatureAI.cpp b/src/server/game/AI/CreatureAI.cpp
index 78ae7cb467..61ca3c80a4 100644
--- a/src/server/game/AI/CreatureAI.cpp
+++ b/src/server/game/AI/CreatureAI.cpp
@@ -134,14 +134,6 @@ void CreatureAI::DoZoneInCombat(Creature* creature /*= nullptr*/, float maxRange
             {
                 creature->AddThreat(player, 0.0f);
             }
-
-            /* Causes certain things to never leave the threat list (Priest Lightwell, etc):
-            for (Unit::ControlSet::const_iterator itr = player->m_Controlled.begin(); itr != player->m_Controlled.end(); ++itr)
-            {
-                creature->SetInCombatWith(*itr);
-                (*itr)->SetInCombatWith(creature);
-                creature->AddThreat(*itr, 0.0f);
-            }*/
         }
     }
 }
@@ -161,7 +153,7 @@ void CreatureAI::MoveInLineOfSight_Safe(Unit* who)
 
 void CreatureAI::MoveInLineOfSight(Unit* who)
 {
-    if (me->GetVictim())
+    if (me->IsEngaged())
         return;
 
     // pussywizard: civilian, non-combat pet or any other NOT HOSTILE TO ANYONE (!)
@@ -182,7 +174,7 @@ void CreatureAI::TriggerAlert(Unit const* who) const
     if (!who || who->GetTypeId() != TYPEID_PLAYER)
         return;
     // If this unit isn't an NPC, is already distracted, is in combat, is confused, stunned or fleeing, do nothing
-    if (me->GetTypeId() != TYPEID_UNIT || me->IsInCombat() || me->HasUnitState(UNIT_STATE_CONFUSED | UNIT_STATE_STUNNED | UNIT_STATE_FLEEING | UNIT_STATE_DISTRACTED))
+    if (me->GetTypeId() != TYPEID_UNIT || me->IsEngaged() || me->HasUnitState(UNIT_STATE_CONFUSED | UNIT_STATE_STUNNED | UNIT_STATE_FLEEING | UNIT_STATE_DISTRACTED))
         return;
     // Only alert for hostiles!
     if (me->IsCivilian() || me->HasReactState(REACT_PASSIVE) || !me->IsHostileTo(who) || !me->_IsTargetAcceptable(who))
@@ -253,7 +245,7 @@ void CreatureAI::SetGazeOn(Unit* target)
 
 bool CreatureAI::UpdateVictimWithGaze()
 {
-    if (!me->IsInCombat())
+    if (!me->IsEngaged())
         return false;
 
     if (me->HasReactState(REACT_PASSIVE))
@@ -271,7 +263,7 @@ bool CreatureAI::UpdateVictimWithGaze()
 
 bool CreatureAI::UpdateVictim()
 {
-    if (!me->IsInCombat())
+    if (!me->IsEngaged())
         return false;
 
     if (!me->HasReactState(REACT_PASSIVE))
diff --git a/src/server/game/AI/CreatureAI.h b/src/server/game/AI/CreatureAI.h
index 6fac18ba35..e74b065a9e 100644
--- a/src/server/game/AI/CreatureAI.h
+++ b/src/server/game/AI/CreatureAI.h
@@ -114,7 +114,7 @@ public:
     // Called for reaction at stopping attack at no attackers or targets
     virtual void EnterEvadeMode(EvadeReason why = EVADE_REASON_OTHER);
 
-    // Called for reaction at enter to combat if not in combat yet (enemy can be nullptr)
+    // Called for reaction when initially engaged
     virtual void EnterCombat(Unit* /*victim*/) {}
 
     // Called when the creature is killed
diff --git a/src/server/game/AI/ScriptedAI/ScriptedCreature.cpp b/src/server/game/AI/ScriptedAI/ScriptedCreature.cpp
index a0b29741b4..85b3c39f5a 100644
--- a/src/server/game/AI/ScriptedAI/ScriptedCreature.cpp
+++ b/src/server/game/AI/ScriptedAI/ScriptedCreature.cpp
@@ -574,7 +574,7 @@ void BossAI::TeleportCheaters()
 void BossAI::JustSummoned(Creature* summon)
 {
     summons.Summon(summon);
-    if (me->IsInCombat())
+    if (me->IsEngaged())
         DoZoneInCombat(summon);
 }
 
diff --git a/src/server/game/AI/SmartScripts/SmartScript.cpp b/src/server/game/AI/SmartScripts/SmartScript.cpp
index fe49a34794..1f8cb70307 100644
--- a/src/server/game/AI/SmartScripts/SmartScript.cpp
+++ b/src/server/game/AI/SmartScripts/SmartScript.cpp
@@ -4044,18 +4044,18 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             ProcessTimedAction(e, e.event.minMaxRepeat.repeatMin, e.event.minMaxRepeat.repeatMax);
             break;
         case SMART_EVENT_UPDATE_OOC:
-            if (me && me->IsInCombat())
+            if (me && me->IsEngaged())
                 return;
             ProcessTimedAction(e, e.event.minMaxRepeat.repeatMin, e.event.minMaxRepeat.repeatMax);
             break;
         case SMART_EVENT_UPDATE_IC:
-            if (!me || !me->IsInCombat())
+            if (!me || !me->IsEngaged())
                 return;
             ProcessTimedAction(e, e.event.minMaxRepeat.repeatMin, e.event.minMaxRepeat.repeatMax);
             break;
         case SMART_EVENT_HEALTH_PCT:
             {
-                if (!me || !me->IsInCombat() || !me->GetMaxHealth())
+                if (!me || !me->IsEngaged() || !me->GetMaxHealth())
                     return;
                 uint32 perc = (uint32)me->GetHealthPct();
                 if (perc > e.event.minMaxRepeat.max || perc < e.event.minMaxRepeat.min)
@@ -4065,7 +4065,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_TARGET_HEALTH_PCT:
             {
-                if (!me || !me->IsInCombat() || !me->GetVictim() || !me->GetVictim()->GetMaxHealth())
+                if (!me || !me->IsEngaged() || !me->GetVictim() || !me->GetVictim()->GetMaxHealth())
                     return;
                 uint32 perc = (uint32)me->GetVictim()->GetHealthPct();
                 if (perc > e.event.minMaxRepeat.max || perc < e.event.minMaxRepeat.min)
@@ -4075,7 +4075,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_MANA_PCT:
             {
-                if (!me || !me->IsInCombat() || !me->GetMaxPower(POWER_MANA))
+                if (!me || !me->IsEngaged() || !me->GetMaxPower(POWER_MANA))
                     return;
                 uint32 perc = uint32(me->GetPowerPct(POWER_MANA));
                 if (perc > e.event.minMaxRepeat.max || perc < e.event.minMaxRepeat.min)
@@ -4085,7 +4085,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_TARGET_MANA_PCT:
             {
-                if (!me || !me->IsInCombat() || !me->GetVictim() || !me->GetVictim()->GetMaxPower(POWER_MANA))
+                if (!me || !me->IsEngaged() || !me->GetVictim() || !me->GetVictim()->GetMaxPower(POWER_MANA))
                     return;
                 uint32 perc = uint32(me->GetVictim()->GetPowerPct(POWER_MANA));
                 if (perc > e.event.minMaxRepeat.max || perc < e.event.minMaxRepeat.min)
@@ -4095,7 +4095,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_RANGE:
             {
-                if (!me || !me->IsInCombat() || !me->GetVictim())
+                if (!me || !me->IsEngaged() || !me->GetVictim())
                     return;
 
                 if (me->IsInRange(me->GetVictim(), (float)e.event.minMaxRepeat.min, (float)e.event.minMaxRepeat.max))
@@ -4106,7 +4106,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_VICTIM_CASTING:
             {
-                if (!me || !me->IsInCombat())
+                if (!me || !me->IsEngaged())
                     return;
 
                 Unit* victim = me->GetVictim();
@@ -4124,7 +4124,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_FRIENDLY_HEALTH:
             {
-                if (!me || !me->IsInCombat())
+                if (!me || !me->IsEngaged())
                     return;
 
                 Unit* target = DoSelectLowestHpFriendly((float)e.event.friendlyHealth.radius, e.event.friendlyHealth.hpDeficit);
@@ -4139,7 +4139,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_FRIENDLY_IS_CC:
             {
-                if (!me || !me->IsInCombat())
+                if (!me || !me->IsEngaged())
                     return;
 
                 std::list<Creature*> pList;
@@ -4285,7 +4285,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_OOC_LOS:
             {
-                if (!me || me->IsInCombat())
+                if (!me || me->IsEngaged())
                     return;
                 //can trigger if closer than fMaxAllowedRange
                 float range = (float)e.event.los.maxDist;
@@ -4309,7 +4309,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_IC_LOS:
             {
-                if (!me || !me->IsInCombat())
+                if (!me || !me->IsEngaged())
                     return;
                 //can trigger if closer than fMaxAllowedRange
                 float range = (float)e.event.los.maxDist;
@@ -4507,7 +4507,7 @@ void SmartScript::ProcessEvent(SmartScriptHolder& e, Unit* unit, uint32 var0, ui
             }
         case SMART_EVENT_FRIENDLY_HEALTH_PCT:
             {
-                if (!me || !me->IsInCombat())
+                if (!me || !me->IsEngaged())
                     return;
 
                 Unit* target = nullptr;
@@ -4701,10 +4701,10 @@ void SmartScript::UpdateTimer(SmartScriptHolder& e, uint32 const diff)
     if (e.event.event_phase_mask && !IsInPhase(e.event.event_phase_mask))
         return;
 
-    if (e.GetEventType() == SMART_EVENT_UPDATE_IC && (!me || !me->IsInCombat()))
+    if (e.GetEventType() == SMART_EVENT_UPDATE_IC && (!me || !me->IsEngaged()))
         return;
 
-    if (e.GetEventType() == SMART_EVENT_UPDATE_OOC && (me && me->IsInCombat()))//can be used with me=nullptr (go script)
+    if (e.GetEventType() == SMART_EVENT_UPDATE_OOC && (me && me->IsEngaged()))//can be used with me=nullptr (go script)
         return;
 
     if (e.timer < diff)
@@ -4982,7 +4982,7 @@ void SmartScript::OnMoveInLineOfSight(Unit* who)
     if (!me)
         return;
 
-    ProcessEventsFor(me->IsInCombat() ? SMART_EVENT_IC_LOS : SMART_EVENT_OOC_LOS, who);
+    ProcessEventsFor(me->IsEngaged() ? SMART_EVENT_IC_LOS : SMART_EVENT_OOC_LOS, who);
 }
 
 /*
diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index ca2da341d1..50dc8391d9 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -704,7 +704,7 @@ void Creature::Update(uint32 diff)
                 }
 
                 // periodic check to see if the creature has passed an evade boundary
-                if (IsAIEnabled && !IsInEvadeMode() && IsInCombat())
+                if (IsAIEnabled && !IsInEvadeMode() && IsEngaged())
                 {
                     if (diff >= m_boundaryCheckTime)
                     {
@@ -1838,7 +1838,7 @@ bool Creature::CanStartAttack(Unit const* who) const
     // pussywizard: at this point we are either hostile to who or friendly to who->getAttackerForHelper()
     // pussywizard: if who is in combat and has an attacker, help him if the distance is right (help because who is hostile or help because attacker is friendly)
     bool assist = false;
-    if (who->IsInCombat() && IsWithinDist(who, ATTACK_DISTANCE))
+    if (who->IsEngaged() && IsWithinDist(who, ATTACK_DISTANCE))
         if (Unit* victim = who->getAttackerForHelper())
             if (IsWithinDistInMap(victim, sWorld->getFloatConfig(CONFIG_CREATURE_FAMILY_ASSISTANCE_RADIUS)))
                 assist = true;
@@ -2357,7 +2357,7 @@ bool Creature::CanAssistTo(Unit const* u, Unit const* enemy, bool checkfaction /
         return false;
 
     // skip fighting creature
-    if (IsInCombat())
+    if (IsEngaged())
         return false;
 
     // only free creature
@@ -2408,11 +2408,10 @@ bool Creature::_IsTargetAcceptable(Unit const* target) const
             return false;
     }
 
-    Unit const* myVictim = getAttackerForHelper();
     Unit const* targetVictim = target->getAttackerForHelper();
 
     // if I'm already fighting target, or I'm hostile towards the target, the target is acceptable
-    if (myVictim == target || targetVictim == this || IsHostileTo(target))
+    if (IsEngagedBy(target) || IsHostileTo(target))
         return true;
 
     // if the target's victim is friendly, and the target is neutral, the target is acceptable
diff --git a/src/server/game/Entities/Creature/CreatureGroups.cpp b/src/server/game/Entities/Creature/CreatureGroups.cpp
index 6bfcb211fe..daaf52be0e 100644
--- a/src/server/game/Entities/Creature/CreatureGroups.cpp
+++ b/src/server/game/Entities/Creature/CreatureGroups.cpp
@@ -190,7 +190,7 @@ void CreatureGroup::RemoveMember(Creature* member)
     member->SetFormation(nullptr);
 }
 
-void CreatureGroup::MemberAttackStart(Creature* member, Unit* target)
+void CreatureGroup::MemberEngagingTarget(Creature* member, Unit* target)
 {
     uint8 const groupAI = sFormationMgr->CreatureGroupMap[member->GetSpawnId()].groupAI;
     if (member == m_leader)
diff --git a/src/server/game/Entities/Creature/CreatureGroups.h b/src/server/game/Entities/Creature/CreatureGroups.h
index 26c4826ef2..6cc3157b8b 100644
--- a/src/server/game/Entities/Creature/CreatureGroups.h
+++ b/src/server/game/Entities/Creature/CreatureGroups.h
@@ -106,7 +106,7 @@ public:
     void FormationReset(bool dismiss, bool initMotionMaster);
 
     void LeaderMoveTo(float x, float y, float z, bool run);
-    void MemberAttackStart(Creature* member, Unit* target);
+    void MemberEngagingTarget(Creature* member, Unit* target);
     void MemberEvaded(Creature* member);
 
 private:
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 7f55ca1494..4f972f3b97 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -13150,7 +13150,7 @@ void Unit::SetInCombatState(bool PvP, Unit* enemy, uint32 duration)
                 creature->AI()->EnterCombat(enemy);
 
             if (creature->GetFormation())
-                creature->GetFormation()->MemberAttackStart(creature, enemy);
+                creature->GetFormation()->MemberEngagingTarget(creature, enemy);
         }
 
         creature->RefreshSwimmingFlag();
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 55b133428f..b08456ad7d 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -1326,6 +1326,7 @@ public:
     bool IsWithinCombatRange(Unit const* obj, float dist2compare) const;
     bool IsWithinMeleeRange(Unit const* obj, float dist = 0.f) const;
     float GetMeleeRange(Unit const* target) const;
+    [[nodiscard]] virtual SpellSchoolMask GetMeleeDamageSchoolMask() const;
     bool GetRandomContactPoint(Unit const* target, float& x, float& y, float& z, bool force = false) const;
     uint32 m_extraAttacks;
     bool m_canDualWield;
@@ -1343,6 +1344,9 @@ public:
         if (GetVictim() != nullptr)
             return GetVictim();
 
+        if (!IsEngaged())
+            return nullptr;
+
         if (!m_attackers.empty())
             return *(m_attackers.begin());
 
@@ -1643,6 +1647,9 @@ public:
 
     [[nodiscard]] bool IsInFlight()  const { return HasUnitState(UNIT_STATE_IN_FLIGHT); }
 
+    bool IsEngaged() const { return IsInCombat(); }
+    bool IsEngagedBy(Unit const* who) const { return IsInCombatWith(who); }
+
     [[nodiscard]] bool IsInCombat() const { return HasUnitFlag(UNIT_FLAG_IN_COMBAT); }
     bool IsInCombatWith(Unit const* who) const;
 
@@ -2103,6 +2110,7 @@ public:
     void TauntApply(Unit* victim);
     void TauntFadeOut(Unit* taunter);
     ThreatMgr& GetThreatMgr() { return m_ThreatMgr; }
+    ThreatMgr const& GetThreatMgr() const { return m_ThreatMgr; }
     void addHatedBy(HostileReference* pHostileReference) { m_HostileRefMgr.insertFirst(pHostileReference); };
     void removeHatedBy(HostileReference* /*pHostileReference*/) { /* nothing to do yet */ }
     HostileRefMgr& getHostileRefMgr() { return m_HostileRefMgr; }
@@ -2473,8 +2481,6 @@ protected:
     CharmInfo* m_charmInfo;
     SharedVisionList m_sharedVision;
 
-    [[nodiscard]] virtual SpellSchoolMask GetMeleeDamageSchoolMask() const;
-
     MotionMaster* i_motionMaster;
 
     uint32 m_reactiveTimer[MAX_REACTIVE];
diff --git a/src/server/game/Spells/SpellEffects.cpp b/src/server/game/Spells/SpellEffects.cpp
index 2fb4afd0b8..c240f62c5b 100644
--- a/src/server/game/Spells/SpellEffects.cpp
+++ b/src/server/game/Spells/SpellEffects.cpp
@@ -2677,7 +2677,7 @@ void Spell::EffectDistract(SpellEffIndex /*effIndex*/)
         return;
 
     // Check for possible target
-    if (!unitTarget || unitTarget->IsInCombat())
+    if (!unitTarget || unitTarget->IsEngaged())
         return;
 
     // target must be OK to do this
diff --git a/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_priestess_delrissa.cpp b/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_priestess_delrissa.cpp
index 32b16bb089..43796d624b 100644
--- a/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_priestess_delrissa.cpp
+++ b/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_priestess_delrissa.cpp
@@ -339,7 +339,7 @@ struct boss_priestess_lackey_commonAI : public ScriptedAI
     void EnterCombat(Unit* who) override
     {
         if (Creature* delrissa = ObjectAccessor::GetCreature(*me, instance->GetGuidData(NPC_DELRISSA)))
-            if (delrissa->IsAlive() && !delrissa->IsInCombat())
+            if (delrissa->IsAlive() && !delrissa->IsEngaged())
                 delrissa->AI()->AttackStart(who);
 
         events.ScheduleEvent(EVENT_SPELL_HELPER_HEALING_POTION, 1000);