fix(Core/Auras): SPELL_AURA_MOD_SCALE should scale additively instead… (#14425)

...multiplicatively

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

src/server/game/Entities/Creature/Creature.cpp

@@ -474,7 +474,7 @@ bool Creature::InitEntry(uint32 Entry, const CreatureData* data)
     SetSpeed(MOVE_FLIGHT, cinfo->speed_flight);
 
     // Will set UNIT_FIELD_BOUNDINGRADIUS and UNIT_FIELD_COMBATREACH
-    SetObjectScale(cinfo->scale);
+    SetObjectScale(GetNativeObjectScale());
 
     SetFloatValue(UNIT_FIELD_HOVERHEIGHT, cinfo->HoverHeight);
 
@@ -3350,6 +3350,11 @@ void Creature::UpdateMovementFlags()
     SetSwim(CanSwim() && Swim);
 }
 
+float Creature::GetNativeObjectScale() const
+{
+    return GetCreatureTemplate()->scale;
+}
+
 void Creature::SetObjectScale(float scale)
 {
     Unit::SetObjectScale(scale);

src/server/game/Entities/Creature/Creature.h

@@ -51,6 +51,7 @@ public:
     void AddToWorld() override;
     void RemoveFromWorld() override;
 
+    float GetNativeObjectScale() const override;
     void SetObjectScale(float scale) override;
     void SetDisplayId(uint32 modelId) override;
 

src/server/game/Entities/Pet/Pet.cpp

@@ -1073,20 +1073,8 @@ bool Guardian::InitStatsForLevel(uint8 petlevel)
 
     SetFloatValue(UNIT_MOD_CAST_SPEED, 1.0f);
 
-    //scale
-    CreatureFamilyEntry const* cFamily = sCreatureFamilyStore.LookupEntry(cinfo->family);
-    if (cFamily && cFamily->minScale > 0.0f && petType == HUNTER_PET)
-    {
-        float scale;
-        if (GetLevel() >= cFamily->maxScaleLevel)
-            scale = 1.0f;
-        else if (GetLevel() <= cFamily->minScaleLevel)
-            scale = 0.5f;
-        else
-            scale = 0.5f + 0.5f * float(GetLevel() - cFamily->minScaleLevel) / float(cFamily->maxScaleLevel  - cFamily->minScaleLevel);
-
-        SetObjectScale(scale);
-    }
+    // scale
+    SetObjectScale(GetNativeObjectScale());
 
     // Resistance
     // xinef: hunter pets should not inherit template resistances
@@ -2440,6 +2428,25 @@ Player* Pet::GetOwner() const
     return m_owner;
 }
 
+float Pet::GetNativeObjectScale() const
+{
+    CreatureFamilyEntry const* creatureFamily = sCreatureFamilyStore.LookupEntry(GetCreatureTemplate()->family);
+    if (creatureFamily && creatureFamily->minScale > 0.0f && getPetType() == HUNTER_PET)
+    {
+        float scale;
+        if (GetLevel() >= creatureFamily->maxScaleLevel)
+            scale = creatureFamily->maxScale;
+        else if (GetLevel() <= creatureFamily->minScaleLevel)
+            scale = creatureFamily->minScale;
+        else
+            scale = creatureFamily->minScale + float(GetLevel() - creatureFamily->minScaleLevel) / creatureFamily->maxScaleLevel * (creatureFamily->maxScale - creatureFamily->minScale);
+
+        return scale;
+    }
+
+    return Guardian::GetNativeObjectScale();
+}
+
 std::string Pet::GenerateActionBarData() const
 {
     std::ostringstream oss;

src/server/game/Entities/Pet/Pet.h

@@ -45,6 +45,7 @@ public:
     void AddToWorld() override;
     void RemoveFromWorld() override;
 
+    float GetNativeObjectScale() const override;
     void SetDisplayId(uint32 modelId) override;
 
     PetType getPetType() const { return m_petType; }

src/server/game/Entities/Unit/Unit.cpp

@@ -16864,6 +16864,14 @@ bool Unit::IsPolymorphed() const
     return spellInfo->GetSpellSpecific() == SPELL_SPECIFIC_MAGE_POLYMORPH;
 }
 
+void Unit::RecalculateObjectScale()
+{
+    int32 scaleAuras = GetTotalAuraModifier(SPELL_AURA_MOD_SCALE) + GetTotalAuraModifier(SPELL_AURA_MOD_SCALE_2);
+    float scale = GetNativeObjectScale() + CalculatePct(1.0f, scaleAuras);
+    float scaleMin = GetTypeId() == TYPEID_PLAYER ? 0.1f : 0.01f;
+    SetObjectScale(std::max(scale, scaleMin));
+}
+
 void Unit::SetDisplayId(uint32 modelId)
 {
     SetUInt32Value(UNIT_FIELD_DISPLAYID, modelId);

src/server/game/Entities/Unit/Unit.h

@@ -2162,6 +2162,8 @@ public:
     void AddInterruptMask(uint32 mask) { m_interruptMask |= mask; }
     void UpdateInterruptMask();
 
+    virtual float GetNativeObjectScale() const { return 1.0f; }
+    virtual void RecalculateObjectScale();
     [[nodiscard]] uint32 GetDisplayId() const { return GetUInt32Value(UNIT_FIELD_DISPLAYID); }
     virtual void SetDisplayId(uint32 modelId);
     [[nodiscard]] uint32 GetNativeDisplayId() const { return GetUInt32Value(UNIT_FIELD_NATIVEDISPLAYID); }

src/server/game/Spells/Auras/SpellAuraEffects.cpp

@@ -2349,16 +2349,12 @@ void AuraEffect::HandleAuraTransform(AuraApplication const* aurApp, uint8 mode,
     }
 }
 
-void AuraEffect::HandleAuraModScale(AuraApplication const* aurApp, uint8 mode, bool apply) const
+void AuraEffect::HandleAuraModScale(AuraApplication const* aurApp, uint8 mode, bool /*apply*/) const
 {
     if (!(mode & AURA_EFFECT_HANDLE_CHANGE_AMOUNT_SEND_FOR_CLIENT_MASK))
         return;
 
-    Unit* target = aurApp->GetTarget();
-
-    float scale = target->GetObjectScale();
-    ApplyPercentModFloatVar(scale, float(GetAmount()), apply);
-    target->SetObjectScale(scale);
+    aurApp->GetTarget()->RecalculateObjectScale();
 }
 
 void AuraEffect::HandleAuraCloneCaster(AuraApplication const* aurApp, uint8 mode, bool apply) const