Core/Units: Fixed melee range check (#17693)

* Split Spell::CheckRange() into 2 methods since that method had more than one responsibility.
* Moved melee range logic into its own function
* Moved melee range logic method GetMeleeRange from Spell to Unit class. Unit::IsWithinMeleeRange() and Spell::GetMinMaxRange() both use that method.

4 files changed, 54 insertions, 47 deletions

diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index a3e20b7c07d..80f2531e223 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -485,11 +485,17 @@ bool Unit::IsWithinMeleeRange(Unit const* obj) const
     float dz = GetPositionZMinusOffset() - obj->GetPositionZMinusOffset();
     float distsq = dx*dx + dy*dy + dz*dz;
 
-    float maxdist = GetCombatReach() + obj->GetCombatReach() + 4.0f / 3.0f;
+    float maxdist = GetMeleeRange(obj);
 
     return distsq <= maxdist * maxdist;
 }
 
+float Unit::GetMeleeRange(Unit const* target) const
+{
+    float range = GetCombatReach() + target->GetCombatReach() + 4.0f / 3.0f;
+    return std::max(range, NOMINAL_MELEE_RANGE);
+}
+
 void Unit::GetRandomContactPoint(const Unit* obj, float &x, float &y, float &z, float distance2dMin, float distance2dMax) const
 {
     float combat_reach = GetCombatReach();
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 4589ec9a180..5162d2398c3 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -1291,6 +1291,7 @@ class TC_GAME_API Unit : public WorldObject
         float GetCombatReach() const { return m_floatValues[UNIT_FIELD_COMBATREACH]; }
         bool IsWithinCombatRange(const Unit* obj, float dist2compare) const;
         bool IsWithinMeleeRange(Unit const* obj) const;
+        float GetMeleeRange(Unit const* target) const;
         void GetRandomContactPoint(const Unit* target, float &x, float &y, float &z, float distance2dMin, float distance2dMax) const;
         uint32 m_extraAttacks;
         bool m_canDualWield;
diff --git a/src/server/game/Spells/Spell.cpp b/src/server/game/Spells/Spell.cpp
index 5e58a602a43..8fc8282b549 100644
--- a/src/server/game/Spells/Spell.cpp
+++ b/src/server/game/Spells/Spell.cpp
@@ -5831,46 +5831,69 @@ SpellCastResult Spell::CheckRange(bool strict)
     if (!strict && m_casttime == 0)
         return SPELL_CAST_OK;
 
+    float minRange, maxRange;
+    std::tie(minRange, maxRange) = GetMinMaxRange(strict);
+
+    // get square values for sqr distance checks
+    minRange *= minRange;
+    maxRange *= maxRange;
+
     Unit* target = m_targets.GetUnitTarget();
+    if (target && target != m_caster)
+    {
+        if (m_caster->GetExactDistSq(target) > maxRange)
+            return SPELL_FAILED_OUT_OF_RANGE;
+
+        if (minRange > 0.0f && m_caster->GetExactDistSq(target) < minRange)
+            return SPELL_FAILED_OUT_OF_RANGE;
+
+        if (m_caster->GetTypeId() == TYPEID_PLAYER &&
+            (m_spellInfo->FacingCasterFlags & SPELL_FACING_FLAG_INFRONT) && !m_caster->HasInArc(static_cast<float>(M_PI), target))
+            return SPELL_FAILED_UNIT_NOT_INFRONT;
+    }
+
+    if (m_targets.HasDst() && !m_targets.HasTraj())
+    {
+        if (m_caster->GetExactDistSq(m_targets.GetDstPos()) > maxRange)
+            return !(_triggeredCastFlags & TRIGGERED_DONT_REPORT_CAST_ERROR) ? SPELL_FAILED_OUT_OF_RANGE : SPELL_FAILED_DONT_REPORT;
+        if (minRange > 0.0f && m_caster->GetExactDistSq(m_targets.GetDstPos()) < minRange)
+            return !(_triggeredCastFlags & TRIGGERED_DONT_REPORT_CAST_ERROR) ? SPELL_FAILED_OUT_OF_RANGE : SPELL_FAILED_DONT_REPORT;
+    }
+
+    return SPELL_CAST_OK;
+}
+
+std::pair<float, float> Spell::GetMinMaxRange(bool strict)
+{
+    float rangeMod = 0.0f;
     float minRange = 0.0f;
     float maxRange = 0.0f;
-    float rangeMod = 0.0f;
     if (strict && IsNextMeleeSwingSpell())
+    {
         maxRange = 100.0f;
-    else if (m_spellInfo->RangeEntry)
+        return std::pair<float, float>(minRange, maxRange);
+    }
+
+    if (m_spellInfo->RangeEntry)
     {
+        Unit* target = m_targets.GetUnitTarget();
         if (m_spellInfo->RangeEntry->type & SPELL_RANGE_MELEE)
         {
-            rangeMod = m_caster->GetCombatReach() + 4.0f / 3.0f;
-            if (target)
-                rangeMod += target->GetCombatReach();
-            else
-                rangeMod += m_caster->GetCombatReach();
-
-            rangeMod = std::max(rangeMod, NOMINAL_MELEE_RANGE);
+            rangeMod = m_caster->GetMeleeRange(target ? target : m_caster); // when the target is not a unit, take the caster's combat reach as the target's combat reach.
         }
         else
         {
             float meleeRange = 0.0f;
             if (m_spellInfo->RangeEntry->type & SPELL_RANGE_RANGED)
-            {
-                meleeRange = m_caster->GetCombatReach() + 4.0f / 3.0f;
-                if (target)
-                    meleeRange += target->GetCombatReach();
-                else
-                    meleeRange += m_caster->GetCombatReach();
-
-                meleeRange = std::max(meleeRange, NOMINAL_MELEE_RANGE);
-            }
+                meleeRange = m_caster->GetMeleeRange(target ? target : m_caster); // when the target is not a unit, take the caster's combat reach as the target's combat reach.
 
             minRange = m_caster->GetSpellMinRangeForTarget(target, m_spellInfo) + meleeRange;
             maxRange = m_caster->GetSpellMaxRangeForTarget(target, m_spellInfo);
 
             if (target || m_targets.GetCorpseTarget())
             {
-                rangeMod = m_caster->GetCombatReach();
-                if (target)
-                    rangeMod += target->GetCombatReach();
+                rangeMod = m_caster->GetCombatReach() + (target ? target->GetCombatReach() : m_caster->GetCombatReach());
+
 
                 if (minRange > 0.0f && !(m_spellInfo->RangeEntry->type & SPELL_RANGE_RANGED))
                     minRange += rangeMod;
@@ -5891,31 +5914,7 @@ SpellCastResult Spell::CheckRange(bool strict)
 
     maxRange += rangeMod;
 
-    minRange *= minRange;
-    maxRange *= maxRange;
-
-    if (target && target != m_caster)
-    {
-        if (m_caster->GetExactDistSq(target) > maxRange)
-            return SPELL_FAILED_OUT_OF_RANGE;
-
-        if (minRange > 0.0f && m_caster->GetExactDistSq(target) < minRange)
-            return SPELL_FAILED_OUT_OF_RANGE;
-
-        if (m_caster->GetTypeId() == TYPEID_PLAYER &&
-            (m_spellInfo->FacingCasterFlags & SPELL_FACING_FLAG_INFRONT) && !m_caster->HasInArc(static_cast<float>(M_PI), target))
-            return SPELL_FAILED_UNIT_NOT_INFRONT;
-    }
-
-    if (m_targets.HasDst() && !m_targets.HasTraj())
-    {
-        if (m_caster->GetExactDistSq(m_targets.GetDstPos()) > maxRange)
-            return !(_triggeredCastFlags & TRIGGERED_DONT_REPORT_CAST_ERROR) ? SPELL_FAILED_OUT_OF_RANGE : SPELL_FAILED_DONT_REPORT;
-        if (minRange > 0.0f && m_caster->GetExactDistSq(m_targets.GetDstPos()) < minRange)
-            return !(_triggeredCastFlags & TRIGGERED_DONT_REPORT_CAST_ERROR) ? SPELL_FAILED_OUT_OF_RANGE : SPELL_FAILED_DONT_REPORT;
-    }
-
-    return SPELL_CAST_OK;
+    return std::pair<float, float>(minRange, maxRange);
 }
 
 SpellCastResult Spell::CheckPower()
diff --git a/src/server/game/Spells/Spell.h b/src/server/game/Spells/Spell.h
index 46384fc54ec..c834d187720 100644
--- a/src/server/game/Spells/Spell.h
+++ b/src/server/game/Spells/Spell.h
@@ -507,6 +507,7 @@ class TC_GAME_API Spell
         void CancelGlobalCooldown();
 
         void SendLoot(ObjectGuid guid, LootType loottype);
+        std::pair<float, float> GetMinMaxRange(bool strict);
 
         Unit* const m_caster;