Core/Auras: Implement SpellAuraInterruptFlags2::StartOfEncounter (#28938)

Co-authored-by: Shauren <shauren.trinity@gmail.com>

5 files changed, 17 insertions, 3 deletions

diff --git a/src/server/game/Battlegrounds/Battleground.cpp b/src/server/game/Battlegrounds/Battleground.cpp
index a8a94b88733..21ca45d99db 100644
--- a/src/server/game/Battlegrounds/Battleground.cpp
+++ b/src/server/game/Battlegrounds/Battleground.cpp
@@ -481,6 +481,10 @@ inline void Battleground::_ProcessJoin(uint32 diff)
         SetStatus(STATUS_IN_PROGRESS);
         SetStartDelayTime(StartDelayTimes[BG_STARTING_EVENT_FOURTH]);
 
+        for (auto const& [guid, _] : GetPlayers())
+            if (Player* player = ObjectAccessor::FindPlayer(guid))
+                player->AtStartOfEncounter();
+
         // Remove preparation
         if (isArena())
         {
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 502186b35d8..e4e24b34ce4 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -536,6 +536,14 @@ void Unit::MonsterMoveWithSpeed(float x, float y, float z, float speed, bool gen
     GetMotionMaster()->LaunchMoveSpline(std::move(initializer), 0, MOTION_PRIORITY_NORMAL, POINT_MOTION_TYPE);
 }
 
+void Unit::AtStartOfEncounter()
+{
+    RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags2::StartOfEncounter);
+
+    if (IsAlive())
+        Unit::ProcSkillsAndAuras(this, nullptr, PROC_FLAG_ENCOUNTER_START, PROC_FLAG_NONE, PROC_SPELL_TYPE_MASK_ALL, PROC_SPELL_PHASE_NONE, PROC_HIT_NONE, nullptr, nullptr, nullptr);
+}
+
 void Unit::UpdateSplineMovement(uint32 t_diff)
 {
     if (movespline->Finalized())
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 9fcb05b9ab1..e48e920f056 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -2017,6 +2017,9 @@ class TC_GAME_API Unit : public WorldObject
         virtual void AtEngage(Unit* /*target*/) {}
         virtual void AtDisengage() {}
 
+    public:
+        void AtStartOfEncounter();
+
     private:
 
         void UpdateSplineMovement(uint32 t_diff);
diff --git a/src/server/game/Instances/InstanceScript.cpp b/src/server/game/Instances/InstanceScript.cpp
index b261e31d7aa..9abe63e469f 100644
--- a/src/server/game/Instances/InstanceScript.cpp
+++ b/src/server/game/Instances/InstanceScript.cpp
@@ -409,8 +409,7 @@ bool InstanceScript::SetBossState(uint32 id, EncounterState state)
 
                     instance->DoOnPlayers([](Player* player)
                     {
-                        if (player->IsAlive())
-                            Unit::ProcSkillsAndAuras(player, nullptr, PROC_FLAG_ENCOUNTER_START, PROC_FLAG_NONE, PROC_SPELL_TYPE_MASK_ALL, PROC_SPELL_PHASE_NONE, PROC_HIT_NONE, nullptr, nullptr, nullptr);
+                        player->AtStartOfEncounter();
                     });
                     break;
                 }
diff --git a/src/server/game/Spells/SpellDefines.h b/src/server/game/Spells/SpellDefines.h
index aceff5a7ccd..0af891cbdb3 100644
--- a/src/server/game/Spells/SpellDefines.h
+++ b/src/server/game/Spells/SpellDefines.h
@@ -124,7 +124,7 @@ enum class SpellAuraInterruptFlags2 : uint32
     Jump                        = 0x00000020,
     ChangeSpec                  = 0x00000040,
     AbandonVehicle              = 0x00000080, // Implemented in Unit::_ExitVehicle
-    StartOfEncounter            = 0x00000100, // NYI
+    StartOfEncounter            = 0x00000100, // Implemented in InstanceScript::SetBossState and Battleground::_ProcessJoin
     EndOfEncounter              = 0x00000200, // NYI
     Disconnect                  = 0x00000400, // NYI
     EnteringInstance            = 0x00000800, // Implemented in Map::AddPlayerToMap