Core/Spells: fixed up block mechanics (#28286)

* Ranged attacks can now be blocked
* Implement SPELL_ATTR3_COMPLETELY_BLOCKED
* Fixed a bug which was causing blocking to block entire spell effects regardless if the attribute was present or not
* Fixed a logic mistake which was causing blocks to roll twice (once for effect negation and once on hit)
* No longer send blocked miss conditions in spell_go packets when the spell is not completely blocked to match sniff data

5 files changed, 20 insertions, 49 deletions

diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index eeb8c7410af..1e828f1f33e 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -985,7 +985,7 @@ void Unit::CastStop(uint32 except_spellid)
             InterruptSpell(CurrentSpellTypes(i), false);
 }
 
-void Unit::CalculateSpellDamageTaken(SpellNonMeleeDamage* damageInfo, int32 damage, SpellInfo const* spellInfo, WeaponAttackType attackType, bool crit, Spell* spell /*= nullptr*/)
+void Unit::CalculateSpellDamageTaken(SpellNonMeleeDamage* damageInfo, int32 damage, SpellInfo const* spellInfo, WeaponAttackType attackType, bool crit /*= false*/, bool blocked /*= false*/, Spell* spell /*= nullptr*/)
 {
     if (damage < 0)
         return;
@@ -1003,7 +1003,6 @@ void Unit::CalculateSpellDamageTaken(SpellNonMeleeDamage* damageInfo, int32 dama
         if (Unit::IsDamageReducedByArmor(damageSchoolMask, spellInfo))
             damage = Unit::CalcArmorReducedDamage(this, victim, damage, spellInfo, attackType);
 
-        bool blocked = false;
         // Per-school calc
         switch (spellInfo->DmgClass)
         {
@@ -1011,17 +1010,6 @@ void Unit::CalculateSpellDamageTaken(SpellNonMeleeDamage* damageInfo, int32 dama
             case SPELL_DAMAGE_CLASS_RANGED:
             case SPELL_DAMAGE_CLASS_MELEE:
             {
-                // Physical Damage
-                if (damageSchoolMask & SPELL_SCHOOL_MASK_NORMAL)
-                {
-                    // Spells with this attribute were already calculated in MeleeSpellHitResult
-                    if (!spellInfo->HasAttribute(SPELL_ATTR3_BLOCKABLE_SPELL))
-                    {
-                        // Get blocked status
-                        blocked = isSpellBlocked(victim, spellInfo, attackType);
-                    }
-                }
-
                 if (crit)
                 {
                     damageInfo->HitInfo |= SPELL_HIT_TYPE_CRIT;
@@ -1055,7 +1043,7 @@ void Unit::CalculateSpellDamageTaken(SpellNonMeleeDamage* damageInfo, int32 dama
                 {
                     damageInfo->blocked = victim->GetShieldBlockValue();
                     // double blocked amount if block is critical
-                    if (victim->isBlockCritical())
+                    if (victim->IsBlockCritical())
                         damageInfo->blocked += damageInfo->blocked;
                     if (damage <= int32(damageInfo->blocked))
                     {
@@ -1305,7 +1293,7 @@ void Unit::CalculateMeleeDamage(Unit* victim, CalcDamageInfo* damageInfo, Weapon
             damageInfo->HitInfo    |= HITINFO_BLOCK;
             damageInfo->Blocked     = damageInfo->Target->GetShieldBlockValue();
             // double blocked amount if block is critical
-            if (damageInfo->Target->isBlockCritical())
+            if (damageInfo->Target->IsBlockCritical())
                 damageInfo->Blocked *= 2;
 
             uint32 remainingBlock = damageInfo->Blocked;
@@ -2357,27 +2345,7 @@ void Unit::SendMeleeAttackStop(Unit* victim)
         TC_LOG_DEBUG("entities.unit", "%s stopped attacking", GetGUID().ToString().c_str());
 }
 
-bool Unit::isSpellBlocked(Unit* victim, SpellInfo const* spellProto, WeaponAttackType attackType)
-{
-    // These spells can't be blocked
-    if (spellProto && (spellProto->HasAttribute(SPELL_ATTR0_IMPOSSIBLE_DODGE_PARRY_BLOCK) || spellProto->HasAttribute(SPELL_ATTR3_IGNORE_HIT_RESULT)))
-        return false;
-
-    // Can't block when casting/controlled
-    if (victim->IsNonMeleeSpellCast(false) || victim->HasUnitState(UNIT_STATE_CONTROLLED))
-        return false;
-
-    if (victim->HasAuraType(SPELL_AURA_IGNORE_HIT_DIRECTION) || victim->HasInArc(float(M_PI), this))
-    {
-        float blockChance = GetUnitBlockChance(attackType, victim);
-        if (blockChance && roll_chance_f(blockChance))
-            return true;
-    }
-
-    return false;
-}
-
-bool Unit::isBlockCritical()
+bool Unit::IsBlockCritical()
 {
     if (roll_chance_i(GetTotalAuraModifier(SPELL_AURA_MOD_BLOCK_CRIT_CHANCE)))
         return true;
@@ -2461,7 +2429,7 @@ SpellMissInfo Unit::MeleeSpellHitResult(Unit* victim, SpellInfo const* spellInfo
 
     bool canDodge = !spellInfo->HasAttribute(SPELL_ATTR7_CANT_DODGE);
     bool canParry = !spellInfo->HasAttribute(SPELL_ATTR7_CANT_PARRY);
-    bool canBlock = spellInfo->HasAttribute(SPELL_ATTR3_BLOCKABLE_SPELL);
+    bool canBlock = true; // all melee and ranged attacks can be blocked
 
     // if victim is casting or cc'd it can't avoid attacks
     if (victim->IsNonMeleeSpellCast(false, false, true) || victim->HasUnitState(UNIT_STATE_CONTROLLED))
@@ -2471,7 +2439,7 @@ SpellMissInfo Unit::MeleeSpellHitResult(Unit* victim, SpellInfo const* spellInfo
         canBlock = false;
     }
 
-    // Ranged attacks can only miss, resist and deflect
+    // Ranged attacks can only miss, resist and deflect and get blocked
     if (attType == RANGED_ATTACK)
     {
         canParry = false;
@@ -2485,7 +2453,6 @@ SpellMissInfo Unit::MeleeSpellHitResult(Unit* victim, SpellInfo const* spellInfo
             if (roll < tmp)
                 return SPELL_MISS_DEFLECT;
         }
-        return SPELL_MISS_NONE;
     }
 
     // Check for attack from behind
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 22ce2f53230..b7d8afcf47e 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -1044,7 +1044,7 @@ class TC_GAME_API Unit : public WorldObject
         void SetLastDamagedTargetGuid(ObjectGuid guid) { _lastDamagedTargetGuid = guid; }
         ObjectGuid GetLastDamagedTargetGuid() const { return _lastDamagedTargetGuid; }
 
-        void CalculateSpellDamageTaken(SpellNonMeleeDamage* damageInfo, int32 damage, SpellInfo const* spellInfo, WeaponAttackType attackType = BASE_ATTACK, bool crit = false, Spell* spell = nullptr);
+        void CalculateSpellDamageTaken(SpellNonMeleeDamage* damageInfo, int32 damage, SpellInfo const* spellInfo, WeaponAttackType attackType = BASE_ATTACK, bool crit = false, bool blocked = false, Spell* spell = nullptr);
         void DealSpellDamage(SpellNonMeleeDamage const* damageInfo, bool durabilityLoss);
 
         // player or player's pet resilience (-1%)
@@ -1620,8 +1620,7 @@ class TC_GAME_API Unit : public WorldObject
         uint32 MeleeDamageBonusDone(Unit* pVictim, uint32 damage, WeaponAttackType attType, SpellInfo const* spellProto = nullptr, SpellSchoolMask damageSchoolMask = SPELL_SCHOOL_MASK_NORMAL);
         uint32 MeleeDamageBonusTaken(Unit* attacker, uint32 pdamage, WeaponAttackType attType, SpellInfo const* spellProto = nullptr, SpellSchoolMask damageSchoolMask = SPELL_SCHOOL_MASK_NORMAL);
 
-        bool isSpellBlocked(Unit* victim, SpellInfo const* spellProto, WeaponAttackType attackType = BASE_ATTACK);
-        bool isBlockCritical();
+        bool IsBlockCritical();
         float SpellCritChanceDone(SpellInfo const* spellInfo, SpellSchoolMask schoolMask, WeaponAttackType attackType = BASE_ATTACK, bool isPeriodic = false) const;
         float SpellCritChanceTaken(Unit const* caster, SpellInfo const* spellInfo, SpellSchoolMask schoolMask, float doneChance, WeaponAttackType attackType = BASE_ATTACK, bool isPeriodic = false) const;
         static uint32 SpellCriticalDamageBonus(Unit const* caster, SpellInfo const* spellProto, uint32 damage, Unit* victim);
diff --git a/src/server/game/Spells/Spell.cpp b/src/server/game/Spells/Spell.cpp
index 1cdcd9128e6..30d0467dda3 100644
--- a/src/server/game/Spells/Spell.cpp
+++ b/src/server/game/Spells/Spell.cpp
@@ -2307,7 +2307,7 @@ void Spell::TargetInfo::PreprocessTarget(Spell* spell)
     spell->m_healing = Healing;
 
     _spellHitTarget = nullptr;
-    if (MissCondition == SPELL_MISS_NONE)
+    if (MissCondition == SPELL_MISS_NONE || (MissCondition == SPELL_MISS_BLOCK && !spell->GetSpellInfo()->HasAttribute(SPELL_ATTR3_COMPLETELY_BLOCKED)))
         _spellHitTarget = unit;
     else if (MissCondition == SPELL_MISS_REFLECT && ReflectResult == SPELL_MISS_NONE)
         _spellHitTarget = spell->m_caster->ToUnit();
@@ -2499,7 +2499,7 @@ void Spell::TargetInfo::DoDamageAndTriggers(Spell* spell)
                 caster->SetLastDamagedTargetGuid(spell->unitTarget->GetGUID());
 
                 // Add bonuses and fill damageInfo struct
-                caster->CalculateSpellDamageTaken(&damageInfo, spell->m_damage, spell->m_spellInfo, spell->m_attackType, IsCrit, spell);
+                caster->CalculateSpellDamageTaken(&damageInfo, spell->m_damage, spell->m_spellInfo, spell->m_attackType, IsCrit, MissCondition == SPELL_MISS_BLOCK, spell);
                 Unit::DealDamageMods(damageInfo.target, damageInfo.damage, &damageInfo.absorb);
 
                 // Send log damage message to client
@@ -4437,6 +4437,11 @@ void Spell::UpdateSpellCastDataTargets(WorldPackets::Spells::SpellCastData& data
         }
         else // misses
         {
+            // Only send blocks in spell_go packets if we know that the spell is not going to do anything to the target.
+            // Spells that are partially blocked will send their block result in their according combat log packet.
+            if (targetInfo.MissCondition == SPELL_MISS_BLOCK && !m_spellInfo->HasAttribute(SPELL_ATTR3_COMPLETELY_BLOCKED))
+                continue;
+
             WorldPackets::Spells::SpellMissStatus missStatus;
             missStatus.TargetGUID = targetInfo.TargetGUID;
             missStatus.Reason = targetInfo.MissCondition;
@@ -7642,7 +7647,7 @@ void Spell::DoEffectOnLaunchTarget(TargetInfo& targetInfo, float multiplier, Spe
 {
     Unit* unit = nullptr;
     // In case spell hit target, do all effect on that target
-    if (targetInfo.MissCondition == SPELL_MISS_NONE)
+    if (targetInfo.MissCondition == SPELL_MISS_NONE || (targetInfo.MissCondition == SPELL_MISS_BLOCK && !m_spellInfo->HasAttribute(SPELL_ATTR3_COMPLETELY_BLOCKED)))
         unit = m_caster->GetGUID() == targetInfo.TargetGUID ? m_caster->ToUnit() : ObjectAccessor::GetUnit(*m_caster, targetInfo.TargetGUID);
     // In case spell reflect from target, do all effect on caster (if hit)
     else if (targetInfo.MissCondition == SPELL_MISS_REFLECT && targetInfo.ReflectResult == SPELL_MISS_NONE)
diff --git a/src/server/shared/SharedDefines.h b/src/server/shared/SharedDefines.h
index b19c205d97b..0bdd89004f7 100644
--- a/src/server/shared/SharedDefines.h
+++ b/src/server/shared/SharedDefines.h
@@ -517,7 +517,7 @@ enum SpellAttr3 : uint32
     SPELL_ATTR3_UNK0                             = 0x00000001, // TITLE Unknown attribute 0@Attr3
     SPELL_ATTR3_IGNORE_PROC_SUBCLASS_MASK        = 0x00000002, //  1 Ignores subclass mask check when checking proc
     SPELL_ATTR3_UNK2                             = 0x00000004, // TITLE Unknown attribute 2@Attr3
-    SPELL_ATTR3_BLOCKABLE_SPELL                  = 0x00000008, // TITLE Blockable spell
+    SPELL_ATTR3_COMPLETELY_BLOCKED               = 0x00000008, // TITLE Completely Blocked
     SPELL_ATTR3_IGNORE_RESURRECTION_TIMER        = 0x00000010, // TITLE Ignore resurrection timer
     SPELL_ATTR3_UNK5                             = 0x00000020, // TITLE Unknown attribute 5@Attr3
     SPELL_ATTR3_UNK6                             = 0x00000040, // TITLE Unknown attribute 6@Attr3
diff --git a/src/server/shared/enuminfo_SharedDefines.cpp b/src/server/shared/enuminfo_SharedDefines.cpp
index 31398718e2f..bc6b4d77638 100644
--- a/src/server/shared/enuminfo_SharedDefines.cpp
+++ b/src/server/shared/enuminfo_SharedDefines.cpp
@@ -658,7 +658,7 @@ TC_API_EXPORT EnumText EnumUtils<SpellAttr3>::ToString(SpellAttr3 value)
         case SPELL_ATTR3_UNK0: return { "SPELL_ATTR3_UNK0", "Unknown attribute 0@Attr3", "" };
         case SPELL_ATTR3_IGNORE_PROC_SUBCLASS_MASK: return { "SPELL_ATTR3_IGNORE_PROC_SUBCLASS_MASK", "SPELL_ATTR3_IGNORE_PROC_SUBCLASS_MASK", "1 Ignores subclass mask check when checking proc" };
         case SPELL_ATTR3_UNK2: return { "SPELL_ATTR3_UNK2", "Unknown attribute 2@Attr3", "" };
-        case SPELL_ATTR3_BLOCKABLE_SPELL: return { "SPELL_ATTR3_BLOCKABLE_SPELL", "Blockable spell", "" };
+        case SPELL_ATTR3_COMPLETELY_BLOCKED: return { "SPELL_ATTR3_COMPLETELY_BLOCKED", "Completely Blocked", "" };
         case SPELL_ATTR3_IGNORE_RESURRECTION_TIMER: return { "SPELL_ATTR3_IGNORE_RESURRECTION_TIMER", "Ignore resurrection timer", "" };
         case SPELL_ATTR3_UNK5: return { "SPELL_ATTR3_UNK5", "Unknown attribute 5@Attr3", "" };
         case SPELL_ATTR3_UNK6: return { "SPELL_ATTR3_UNK6", "Unknown attribute 6@Attr3", "" };
@@ -702,7 +702,7 @@ TC_API_EXPORT SpellAttr3 EnumUtils<SpellAttr3>::FromIndex(size_t index)
         case 0: return SPELL_ATTR3_UNK0;
         case 1: return SPELL_ATTR3_IGNORE_PROC_SUBCLASS_MASK;
         case 2: return SPELL_ATTR3_UNK2;
-        case 3: return SPELL_ATTR3_BLOCKABLE_SPELL;
+        case 3: return SPELL_ATTR3_COMPLETELY_BLOCKED;
         case 4: return SPELL_ATTR3_IGNORE_RESURRECTION_TIMER;
         case 5: return SPELL_ATTR3_UNK5;
         case 6: return SPELL_ATTR3_UNK6;
@@ -743,7 +743,7 @@ TC_API_EXPORT size_t EnumUtils<SpellAttr3>::ToIndex(SpellAttr3 value)
         case SPELL_ATTR3_UNK0: return 0;
         case SPELL_ATTR3_IGNORE_PROC_SUBCLASS_MASK: return 1;
         case SPELL_ATTR3_UNK2: return 2;
-        case SPELL_ATTR3_BLOCKABLE_SPELL: return 3;
+        case SPELL_ATTR3_COMPLETELY_BLOCKED: return 3;
         case SPELL_ATTR3_IGNORE_RESURRECTION_TIMER: return 4;
         case SPELL_ATTR3_UNK5: return 5;
         case SPELL_ATTR3_UNK6: return 6;