Core/Players: Corrected shield block value calculations

Port From (https://github.com/TrinityCore/TrinityCore/commit/31d3080091643d4e348ec53c5bec3caf0e17110f)

Source/Game/Entities/Player/Player.Combat.cs

@@ -89,8 +89,6 @@ namespace Game.Entities
             SendPacket(packet);
         }
 
-        public override uint GetBlockPercent() { return m_activePlayerData.ShieldBlock; }
-
         bool CanTitanGrip() { return m_canTitanGrip; }
 
         float GetRatingMultiplier(CombatRating cr)
@@ -344,6 +342,17 @@ namespace Game.Entities
                 UpdateDamagePhysical(attType);
         }
 
+        public override float GetBlockPercent(uint attackerLevel)
+        {
+            float blockArmor = (float)m_activePlayerData.ShieldBlock;
+            float armorConstant = Global.DB2Mgr.EvaluateExpectedStat(ExpectedStatType.ArmorConstant, attackerLevel, -2, 0, Class.None);
+
+            if ((blockArmor + armorConstant) == 0)
+                return 0;
+
+            return Math.Min(blockArmor / (blockArmor + armorConstant), 0.85f);
+        }
+        
         public void SetCanParry(bool value)
         {
             if (m_canParry == value)

Source/Game/Entities/Player/Player.Items.cs

@@ -4239,7 +4239,11 @@ namespace Game.Entities
 
             uint armor = proto.GetArmor(itemLevel);
             if (armor != 0)
+            {
                 HandleStatFlatModifier(UnitMods.Armor, UnitModifierFlatType.Base, (float)armor, apply);
+                if (proto.GetClass() == ItemClass.Armor && (ItemSubClassArmor)proto.GetSubClass() == ItemSubClassArmor.Shield)
+                    SetUpdateFieldValue(m_values.ModifyValue(m_activePlayerData).ModifyValue(m_activePlayerData.ShieldBlock), apply ? (uint)(armor * 2.5f) : 0);
+            }
 
             WeaponAttackType attType = GetAttackBySlot(slot, proto.GetInventoryType());
             if (attType != WeaponAttackType.Max && CanUseAttackType(attType))

Source/Game/Entities/Player/Player.cs

@@ -5761,8 +5761,7 @@ namespace Game.Entities
             SetUpdateFieldValue(m_values.ModifyValue(m_activePlayerData).ModifyValue(m_activePlayerData.ParryPercentage), 0.0f);
             SetUpdateFieldValue(m_values.ModifyValue(m_activePlayerData).ModifyValue(m_activePlayerData.BlockPercentage), 0.0f);
 
-            // Static 30% damage blocked
+            SetUpdateFieldValue(m_values.ModifyValue(m_activePlayerData).ModifyValue(m_activePlayerData.ShieldBlock), 0u);
-            SetUpdateFieldValue(m_values.ModifyValue(m_activePlayerData).ModifyValue(m_activePlayerData.ShieldBlock), 30u);
 
             // Dodge percentage
             SetUpdateFieldValue(m_values.ModifyValue(m_activePlayerData).ModifyValue(m_activePlayerData.DodgePercentage), 0.0f);

Source/Game/Entities/Unit/Unit.Combat.cs

@@ -1710,7 +1710,7 @@ namespace Game.Entities
 
         public void KillSelf(bool durabilityLoss = true) { Kill(this, durabilityLoss); }
 
-        public virtual uint GetBlockPercent() { return 30; }
+        public virtual float GetBlockPercent(uint attackerLevel) { return 30.0f; }
 
         void UpdateReactives(uint p_time)
         {
@@ -1981,7 +1981,7 @@ namespace Game.Entities
                     damageInfo.HitInfo |= HitInfo.Block;
                     damageInfo.originalDamage = damageInfo.damage;
                     // 30% damage blocked, double blocked amount if block is critical
-                    damageInfo.blocked_amount = MathFunctions.CalculatePct(damageInfo.damage, damageInfo.target.IsBlockCritical() ? damageInfo.target.GetBlockPercent() * 2 : damageInfo.target.GetBlockPercent());
+                    damageInfo.blocked_amount = MathFunctions.CalculatePct(damageInfo.damage, damageInfo.target.IsBlockCritical() ? damageInfo.target.GetBlockPercent(GetLevel()) * 2 : damageInfo.target.GetBlockPercent(GetLevel()));
                     damageInfo.damage -= damageInfo.blocked_amount;
                     damageInfo.cleanDamage += damageInfo.blocked_amount;
                     break;
@@ -2780,8 +2780,7 @@ namespace Game.Entities
             uint attackerLevel = attacker.GetLevelForTarget(victim);
             // Expansion and ContentTuningID necessary? Does Player get a ContentTuningID too ?
             float armorConstant = Global.DB2Mgr.EvaluateExpectedStat(ExpectedStatType.ArmorConstant, attackerLevel, -2, 0, attacker.GetClass());
-
+            if ((armor + armorConstant) == 0)
-            if (armorConstant == 0)
                 return damage;
 
             float mitigation = Math.Min(armor / (armor + armorConstant), 0.85f);

Source/Game/Entities/Unit/Unit.Spells.cs

@@ -2418,7 +2418,7 @@ namespace Game.Entities
                         if (blocked)
                         {
                             // double blocked amount if block is critical
-                            uint value = victim.GetBlockPercent();
+                            float value = victim.GetBlockPercent(GetLevel());
                             if (victim.IsBlockCritical())
                                 value *= 2; // double blocked percent
                             damageInfo.blocked = (uint)MathFunctions.CalculatePct(damage, value);