Core/Spells: Implement sqrt based aoe damage diminishing (#29192)

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

1 files changed, 55 insertions, 4 deletions

diff --git a/src/server/game/Spells/Spell.cpp b/src/server/game/Spells/Spell.cpp
index 50483d7b714..ff2c0128e07 100644
--- a/src/server/game/Spells/Spell.cpp
+++ b/src/server/game/Spells/Spell.cpp
@@ -2620,6 +2620,23 @@ void Spell::AddDestTarget(SpellDestination const& dest, uint32 effIndex)
     m_destTargets[effIndex] = dest;
 }
 
+int32 Spell::GetUnitTargetIndexForEffect(ObjectGuid const& target, SpellEffIndex effect) const
+{
+    int32 index = 0;
+    for (TargetInfo const& uniqueTargetInfo : m_UniqueTargetInfo)
+    {
+        if (uniqueTargetInfo.MissCondition == SPELL_MISS_NONE && uniqueTargetInfo.EffectMask & (1 << effect))
+        {
+            if (uniqueTargetInfo.TargetGUID == target)
+                break;
+
+            ++index;
+        }
+    }
+
+    return index;
+}
+
 int64 Spell::GetUnitTargetCountForEffect(SpellEffIndex effect) const
 {
     return std::count_if(m_UniqueTargetInfo.begin(), m_UniqueTargetInfo.end(), [effect](TargetInfo const& targetInfo)
@@ -8297,16 +8314,44 @@ void Spell::DoEffectOnLaunchTarget(TargetInfo& targetInfo, float multiplier, Spe
 
     if (m_originalCaster && m_damage > 0)
     {
-        if (spellEffectInfo.IsTargetingArea() || spellEffectInfo.IsAreaAuraEffect() || spellEffectInfo.IsEffect(SPELL_EFFECT_PERSISTENT_AREA_AURA) || m_spellInfo->HasAttribute(SPELL_ATTR5_TREAT_AS_AREA_EFFECT))
+        bool isAoeTarget = spellEffectInfo.IsTargetingArea() || spellEffectInfo.IsAreaAuraEffect() || spellEffectInfo.IsEffect(SPELL_EFFECT_PERSISTENT_AREA_AURA);
+        if (isAoeTarget || m_spellInfo->HasAttribute(SPELL_ATTR5_TREAT_AS_AREA_EFFECT))
         {
             m_damage = unit->CalculateAOEAvoidance(m_damage, m_spellInfo->SchoolMask, m_originalCaster->GetGUID());
 
             if (m_originalCaster->GetTypeId() == TYPEID_PLAYER)
             {
+                int64 targetCount = !isAoeTarget && m_spellValue->ParentSpellTargetCount ? *m_spellValue->ParentSpellTargetCount : GetUnitTargetCountForEffect(spellEffectInfo.EffectIndex);
+                int32 targetIndex = !isAoeTarget && m_spellValue->ParentSpellTargetIndex ? *m_spellValue->ParentSpellTargetIndex : GetUnitTargetIndexForEffect(targetInfo.TargetGUID, spellEffectInfo.EffectIndex);
+
+                // sqrt target cap damage calculation
+                if (m_spellInfo->SqrtDamageAndHealingDiminishing.MaxTargets
+                    && targetCount > m_spellInfo->SqrtDamageAndHealingDiminishing.MaxTargets
+                    && targetIndex >= m_spellInfo->SqrtDamageAndHealingDiminishing.NumNonDiminishedTargets)
+                    m_damage = m_damage * std::sqrt(float(m_spellInfo->SqrtDamageAndHealingDiminishing.MaxTargets) / std::min(AOE_DAMAGE_TARGET_CAP, targetCount));
+
                 // cap damage of player AOE
-                int64 targetAmount = GetUnitTargetCountForEffect(spellEffectInfo.EffectIndex);
-                if (targetAmount > 20)
-                    m_damage = m_damage * 20 / targetAmount;
+                if (targetCount > AOE_DAMAGE_TARGET_CAP)
+                    m_damage = m_damage * AOE_DAMAGE_TARGET_CAP / targetCount;
+            }
+        }
+    }
+
+    if (m_originalCaster && m_healing > 0)
+    {
+        bool isAoeTarget = spellEffectInfo.IsTargetingArea() || spellEffectInfo.IsAreaAuraEffect() || spellEffectInfo.IsEffect(SPELL_EFFECT_PERSISTENT_AREA_AURA);
+        if (isAoeTarget || m_spellInfo->HasAttribute(SPELL_ATTR5_TREAT_AS_AREA_EFFECT))
+        {
+            if (m_originalCaster->GetTypeId() == TYPEID_PLAYER)
+            {
+                int64 targetCount = !isAoeTarget && m_spellValue->ParentSpellTargetCount ? *m_spellValue->ParentSpellTargetCount : GetUnitTargetCountForEffect(spellEffectInfo.EffectIndex);
+                int32 targetIndex = !isAoeTarget && m_spellValue->ParentSpellTargetIndex ? *m_spellValue->ParentSpellTargetIndex : GetUnitTargetIndexForEffect(targetInfo.TargetGUID, spellEffectInfo.EffectIndex);
+
+                // sqrt target cap healing calculation
+                if (m_spellInfo->SqrtDamageAndHealingDiminishing.MaxTargets
+                    && targetCount > m_spellInfo->SqrtDamageAndHealingDiminishing.MaxTargets
+                    && targetIndex >= m_spellInfo->SqrtDamageAndHealingDiminishing.NumNonDiminishedTargets)
+                    m_healing = m_healing * std::sqrt(float(m_spellInfo->SqrtDamageAndHealingDiminishing.MaxTargets) / std::min(AOE_DAMAGE_TARGET_CAP, targetCount));
             }
         }
     }
@@ -8426,6 +8471,12 @@ void Spell::SetSpellValue(SpellValueMod mod, int32 value)
         case SPELLVALUE_DURATION:
             m_spellValue->Duration = value;
             break;
+        case SPELLVALUE_PARENT_SPELL_TARGET_COUNT:
+            m_spellValue->ParentSpellTargetCount = value;
+            break;
+        case SPELLVALUE_PARENT_SPELL_TARGET_INDEX:
+            m_spellValue->ParentSpellTargetIndex = value;
+            break;
         default:
             break;
     }