fix(Core/Unit): improve leeway bonus range and speed calculations (#25958)

Co-authored-by: GuybrushGit <turinpt3@gmail.com>
Co-authored-by: lightshope <lh@lightshope.org>
Co-authored-by: sidsukana <pgsilent@gmail.com>
Co-authored-by: ratkosrb <ratkomladic2@abv.bg>

src/server/game/Entities/Object/Object.cpp

@@ -1753,6 +1753,56 @@ float WorldObject::GetSightRange(WorldObject const* target) const
     return 0.0f;
 }
 
+float WorldObject::GetLeewayBonusRangeForTargets(Player const* player, Unit const* target)
+{
+    if (!player || !target)
+        return 0.0f;
+
+    constexpr uint32 leewayMoveFlags = MOVEMENTFLAG_FORWARD | MOVEMENTFLAG_STRAFE_LEFT | MOVEMENTFLAG_STRAFE_RIGHT | MOVEMENTFLAG_FALLING;
+    if (player->HasUnitMovementFlag(leewayMoveFlags) && !player->IsWalking() && target->HasUnitMovementFlag(leewayMoveFlags) && !target->IsWalking())
+        return LEEWAY_BONUS_RANGE;
+
+    return 0.0f;
+}
+
+float WorldObject::GetLeewayBonusRange(Unit const* target) const
+{
+    if (!target)
+        return 0.0f;
+
+    if (Player const* player = ToPlayer())
+        return GetLeewayBonusRangeForTargets(player, target);
+
+    if (Player const* playerTarget = target->ToPlayer())
+        return GetLeewayBonusRangeForTargets(playerTarget, ToUnit());
+
+    return 0.0f;
+}
+
+float WorldObject::GetLeewayBonusRadius() const
+{
+    if (Player const* player = ToPlayer())
+    {
+        bool hasLeewayMovement = false;
+
+        if (player->HasUnitState(UNIT_STATE_JUMPING) || player->HasUnitMovementFlag(MOVEMENTFLAG_FALLING))
+            hasLeewayMovement = true;
+        else
+        {
+            float speedXY = (player->m_movementInfo.jump.xyspeed > 0.0f)
+                ? player->m_movementInfo.jump.xyspeed
+                : player->GetSpeed(player->IsWalking() ? MOVE_WALK : MOVE_RUN);
+
+            hasLeewayMovement = speedXY > LEEWAY_MIN_MOVE_SPEED;
+        }
+
+        if (hasLeewayMovement)
+            return LEEWAY_BONUS_RANGE;
+    }
+
+    return 0.0f;
+}
+
 bool WorldObject::CanSeeOrDetect(WorldObject const* obj, bool ignoreStealth, bool distanceCheck, bool checkAlert) const
 {
     if (this == obj)

src/server/game/Entities/Object/Object.h

@@ -605,6 +605,11 @@ public:
     [[nodiscard]] float GetGridActivationRange() const;
     [[nodiscard]] float GetVisibilityRange() const;
     virtual float GetSightRange(WorldObject const* target = nullptr) const;
+
+    [[nodiscard]] static float GetLeewayBonusRangeForTargets(Player const* player, Unit const* target);
+    [[nodiscard]] float GetLeewayBonusRange(Unit const* target) const;
+    [[nodiscard]] float GetLeewayBonusRadius() const;
+
     //bool CanSeeOrDetect(WorldObject const* obj, bool ignoreStealth = false, bool distanceCheck = false) const;
     bool CanSeeOrDetect(WorldObject const* obj, bool ignoreStealth = false, bool distanceCheck = false, bool checkAlert = false) const;
 

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

@@ -792,8 +792,7 @@ bool Unit::IsWithinMeleeRange(Unit const* obj, float dist) const
 
     float maxdist = dist + GetMeleeRange(obj);
 
-    if ((IsPlayer() || obj->IsPlayer()) && HasLeewayMovement() && obj->HasLeewayMovement())
-        maxdist += LEEWAY_BONUS_RANGE;
+    maxdist += GetLeewayBonusRange(obj);
 
     return distsq < maxdist * maxdist;
 }

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

@@ -1729,12 +1729,6 @@ public:
                              UNIT_STATE_ROOT | UNIT_STATE_STUNNED | UNIT_STATE_DISTRACTED) && !GetOwnerGUID();
     }
 
-    [[nodiscard]] bool HasLeewayMovement() const
-    {
-         return m_movementInfo.HasMovementFlag(MOVEMENTFLAG_FORWARD | MOVEMENTFLAG_STRAFE_LEFT | MOVEMENTFLAG_STRAFE_RIGHT | MOVEMENTFLAG_FALLING)
-                && !IsWalking();
-    }
-
     void KnockbackFrom(float x, float y, float speedXY, float speedZ);
     void JumpTo(float speedXY, float speedZ, bool forward = true);
     void JumpTo(WorldObject* obj, float speedZ);

src/server/game/Spells/Spell.cpp

@@ -1248,6 +1248,9 @@ void Spell::SelectImplicitConeTargets(SpellEffIndex effIndex, SpellImplicitTarge
     }
 
     float radius = m_spellInfo->Effects[effIndex].CalcRadius(m_caster) * m_spellValue->RadiusMod;
+
+    radius += m_caster->GetLeewayBonusRadius();
+
     if (uint32 containerTypeMask = GetSearcherTypeMask(objectType, condList))
     {
         Acore::WorldObjectSpellConeTargetCheck check(coneAngle, radius, m_caster, m_spellInfo, selectionType, condList);
@@ -1335,6 +1338,17 @@ void Spell::SelectImplicitAreaTargets(SpellEffIndex effIndex, SpellImplicitTarge
     // Xinef: the distance should be increased by caster size, it is neglected in latter calculations
     std::list<WorldObject*> targets;
     float radius = m_spellInfo->Effects[effIndex].CalcRadius(m_caster) * m_spellValue->RadiusMod;
+    switch (targetType.GetTarget())
+    {
+        case TARGET_UNIT_SRC_AREA_ENEMY:
+        case TARGET_UNIT_CASTER_AREA_PARTY:
+        case TARGET_UNIT_CASTER_AREA_RAID:
+            radius += m_caster->GetLeewayBonusRadius();
+            break;
+        default:
+            break;
+    }
+
     SearchAreaTargets(targets, radius, center, referer, targetType.GetObjectType(), targetType.GetCheckType(), m_spellInfo->Effects[effIndex].ImplicitTargetConditions, Acore::WorldObjectSpellAreaTargetSearchReason::Area);
 
     CallScriptObjectAreaTargetSelectHandlers(targets, effIndex, targetType);
@@ -7088,8 +7102,9 @@ SpellCastResult Spell::CheckRange(bool strict)
             if (range_type == SPELL_RANGE_MELEE)
             {
                 float real_max_range = max_range;
-                if (!m_caster->IsCreature() && m_caster->HasLeewayMovement() && target->HasLeewayMovement())
-                    real_max_range -= MIN_MELEE_REACH; // Because of lag, we can not check too strictly here (is only used if both caster and target are moving)
+
+                if (m_caster->GetLeewayBonusRange(target) > 0.0f)
+                    real_max_range -= MIN_MELEE_REACH; // less strict when leeway applies
                 else
                     real_max_range -= 2 * MIN_MELEE_REACH;
 
@@ -7124,7 +7139,7 @@ SpellCastResult Spell::CheckRange(bool strict)
 
     if (m_targets.HasDst() && !m_targets.HasTraj())
     {
-        if (!m_caster->IsWithinDist3d(m_targets.GetDstPos(), max_range))
+        if (!m_caster->IsWithinDist3d(m_targets.GetDstPos(), max_range + m_caster->GetLeewayBonusRadius()))
             return SPELL_FAILED_OUT_OF_RANGE;
         if (min_range && m_caster->IsWithinDist3d(m_targets.GetDstPos(), min_range))
             return SPELL_FAILED_TOO_CLOSE;