Core/Spells: cleaned up and improved spell focusing behavior

Port From (https://github.com/TrinityCore/TrinityCore/commit/c295cb9814f4c2a1878aa047cefe0cfbc7958f93)

Source/Game/Entities/Creature/Creature.cs

@@ -2975,39 +2975,15 @@ namespace Game.Entities
             _spellFocusInfo.Spell = focusSpell;
 
             bool noTurnDuringCast = spellInfo.HasAttribute(SpellAttr5.DontTurnDuringCast);
+            bool turnDisabled = HasUnitFlag2(UnitFlags2.CannotTurn);
             // set target, then force send update packet to players if it changed to provide appropriate facing
-            ObjectGuid newTarget = target ? target.GetGUID() : ObjectGuid.Empty;
+            ObjectGuid newTarget = (target != null && !noTurnDuringCast && !turnDisabled) ? target.GetGUID() : ObjectGuid.Empty;
             if (GetTarget() != newTarget)
-            {
                 SetUpdateFieldValue(m_values.ModifyValue(m_unitData).ModifyValue(m_unitData.Target), newTarget);
 
-                // here we determine if the (relatively expensive) forced update is worth it, or whether we can afford to wait until the scheduled update tick
+            // If we are not allowed to turn during cast but have a focus target, face the target
-                // only require instant update for spells that actually have a visual
+            if (!turnDisabled && noTurnDuringCast && target)
-                if (spellInfo.GetSpellVisual() != 0 && (focusSpell.GetCastTime() == 0 || // if the spell is instant cast
+                SetFacingToObject(target, false);
-                   noTurnDuringCast)) // client gets confused if we attempt to turn at the regularly scheduled update packet
-                {
-                    List<Unit> playersNearby = GetPlayerListInGrid(GetVisibilityRange());
-                    foreach (Player player in playersNearby)
-                    {
-                        // only update players that are known to the client (have already been created)
-                        if (player.HaveAtClient(this))
-                            SendUpdateToPlayer(player);
-                    }
-                }
-            }
-
-            if (!HasUnitFlag2(UnitFlags2.CannotTurn))
-            {
-                // Face the target - we need to do this before the unit state is modified for no-turn spells
-                if (target)
-                    SetFacingToObject(target, false);
-                else if (!noTurnDuringCast)
-                {
-                    Unit victim = GetVictim();
-                    if (victim)
-                        SetFacingToObject(victim, false); // ensure server-side orientation is correct at beginning of cast
-                }
-            }
 
             if (!noTurnDuringCast)
                 AddUnitState(UnitState.Focusing);

Source/Game/Spells/Auras/AuraEffect.cs

@@ -513,6 +513,18 @@ namespace Game.Spells
 
             Unit target = aurApp.GetTarget();
 
+            // Update serverside orientation of tracking channeled auras on periodic update ticks
+            if (caster != null && m_spellInfo.IsChanneled() && m_spellInfo.HasAttribute(SpellAttr1.ChannelTrackTarget) && !caster.m_unitData.ChannelObjects.Empty())
+            {
+                ObjectGuid channelGuid = caster.m_unitData.ChannelObjects[0];
+                if (channelGuid != caster.GetGUID())
+                {
+                    WorldObject objectTarget = Global.ObjAccessor.GetWorldObject(caster, channelGuid);
+                    if (objectTarget != null)
+                        caster.SetInFront(objectTarget);
+                }
+            }
+
             switch (GetAuraType())
             {
                 case AuraType.PeriodicDummy:

Source/Game/Spells/Spell.cs

@@ -2462,16 +2462,15 @@ namespace Game.Spells
                 }
             }
 
-            // focus if not controlled creature
+            // Creatures focus their target when possible
-            if (m_caster.GetTypeId() == TypeId.Unit && !m_caster.ToUnit().HasUnitFlag(UnitFlags.Possessed))
+            if (m_casttime != 0 && m_caster.IsCreature() && !m_spellInfo.IsNextMeleeSwingSpell() && !IsAutoRepeat() && !m_caster.ToUnit().HasUnitFlag(UnitFlags.Possessed))
             {
-                if (!(m_spellInfo.IsNextMeleeSwingSpell() || IsAutoRepeat()))
+                // Channeled spells and some triggered spells do not focus a cast target. They face their target later on via channel object guid and via spell attribute or not at all
-                {
+                bool focusTarget = !m_spellInfo.IsChanneled() && !_triggeredCastFlags.HasFlag(TriggerCastFlags.IgnoreSetFacing);
-                    if (m_targets.GetObjectTarget() && m_caster != m_targets.GetObjectTarget())
+                if (focusTarget && m_targets.GetObjectTarget() && m_caster != m_targets.GetObjectTarget())
-                        m_caster.ToCreature().SetSpellFocus(this, m_targets.GetObjectTarget());
+                    m_caster.ToCreature().SetSpellFocus(this, m_targets.GetObjectTarget());
-                    else if (m_spellInfo.HasAttribute(SpellAttr5.DontTurnDuringCast))
+                else
-                        m_caster.ToCreature().SetSpellFocus(this, null);
+                    m_caster.ToCreature().SetSpellFocus(this, null);
-                }
             }
 
             // set timer base at cast time
@@ -2641,10 +2640,6 @@ namespace Game.Spells
 
             SetExecutedCurrently(true);
 
-            if (!Convert.ToBoolean(_triggeredCastFlags & TriggerCastFlags.IgnoreSetFacing))
-                if (m_caster.IsTypeId(TypeId.Unit) && m_targets.GetObjectTarget() != null && m_caster != m_targets.GetObjectTarget())
-                    m_caster.ToCreature().SetInFront(m_targets.GetObjectTarget());
-
             // Should this be done for original caster?
             Player modOwner = m_caster.GetSpellModOwner();
             if (modOwner != null)
@@ -2730,17 +2725,11 @@ namespace Game.Spells
                 }
             }
 
-            // if the spell allows the creature to turn while casting, then adjust server-side orientation to face the target now
+            // The spell focusing is making sure that we have a valid cast target guid when we need it so only check for a guid value here.
-            // client-side orientation is handled by the client itself, as the cast target is targeted due to Creature::FocusTarget
+            Creature creatureCaster = m_caster.ToCreature();
-            if (m_caster.IsTypeId(TypeId.Unit) && !m_caster.ToUnit().HasUnitFlag(UnitFlags.Possessed))
+            if (creatureCaster != null)
-            {
+                if (!creatureCaster.GetTarget().IsEmpty() && !creatureCaster.HasUnitFlag(UnitFlags.Possessed))
-                if (!m_spellInfo.HasAttribute(SpellAttr5.DontTurnDuringCast))
+                    creatureCaster.SetInFront(Global.ObjAccessor.GetUnit(creatureCaster, creatureCaster.GetTarget()));
-                {
-                    WorldObject objTarget = m_targets.GetObjectTarget();
-                    if (objTarget != null)
-                        m_caster.ToCreature().SetInFront(objTarget);
-                }
-            }
 
             SelectSpellTargets();
 
@@ -2816,11 +2805,8 @@ namespace Game.Spells
             SendSpellGo();
 
             if (!m_spellInfo.IsChanneled())
-            {
-                Creature creatureCaster = m_caster.ToCreature();
                 if (creatureCaster != null)
                     creatureCaster.ReleaseSpellFocus(this);
-            }
 
             // Okay, everything is prepared. Now we need to distinguish between immediate and evented delayed spells
             if ((m_spellInfo.HasHitDelay() && !m_spellInfo.IsChanneled()) || m_spellInfo.HasAttribute(SpellAttr4.Unk4))