Entities/Unit: Finally fix no-path evasion.

- When a creature cannot find a path to its victim, it begins evading all attacks and regenerating health.
- If this persists for 5 seconds, it evades back to spawn position with new EvadeReason value EVADE_REASON_NO_PATH.
- Also some SmartAI cleanup (why oh why does it have so much duplicated code) and getting rid of #defines in favor of type-checked compile-time constants.

4 files changed, 51 insertions, 45 deletions

diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index 61d5d7d9459..eefd24e203b 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -182,13 +182,13 @@ m_groupLootTimer(0), lootingGroupLowGUID(0), m_PlayerDamageReq(0),
 m_lootRecipient(), m_lootRecipientGroup(0), _skinner(), _pickpocketLootRestore(0), m_corpseRemoveTime(0), m_respawnTime(0),
 m_respawnDelay(300), m_corpseDelay(60), m_respawnradius(0.0f), m_boundaryCheckTime(2500), m_combatPulseTime(0), m_combatPulseDelay(0), m_reactState(REACT_AGGRESSIVE),
 m_defaultMovementType(IDLE_MOTION_TYPE), m_spawnId(0), m_equipmentId(0), m_originalEquipmentId(0), m_AlreadyCallAssistance(false),
-m_AlreadySearchedAssistance(false), m_regenHealth(true), m_AI_locked(false), m_meleeDamageSchoolMask(SPELL_SCHOOL_MASK_NORMAL),
+m_AlreadySearchedAssistance(false), m_regenHealth(true), m_cannotReachTarget(false), m_cannotReachTimer(0), m_AI_locked(false), m_meleeDamageSchoolMask(SPELL_SCHOOL_MASK_NORMAL),
 m_originalEntry(0), m_homePosition(), m_transportHomePosition(), m_creatureInfo(nullptr), m_creatureData(nullptr), m_waypointID(0), m_path_id(0), m_formation(nullptr), m_focusSpell(nullptr), m_focusDelay(0)
 {
     m_regenTimer = CREATURE_REGEN_INTERVAL;
     m_valuesCount = UNIT_END;
 
-    for (uint8 i = 0; i < CREATURE_MAX_SPELLS; ++i)
+    for (uint8 i = 0; i < MAX_CREATURE_SPELLS; ++i)
         m_spells[i] = 0;
 
     DisableReputationGain = false;
@@ -394,7 +394,7 @@ bool Creature::InitEntry(uint32 entry, CreatureData const* data /*= nullptr*/)
     if (!m_respawnradius && m_defaultMovementType == RANDOM_MOTION_TYPE)
         m_defaultMovementType = IDLE_MOTION_TYPE;
 
-    for (uint8 i=0; i < CREATURE_MAX_SPELLS; ++i)
+    for (uint8 i=0; i < MAX_CREATURE_SPELLS; ++i)
         m_spells[i] = GetCreatureTemplate()->spells[i];
 
     return true;
@@ -648,33 +648,32 @@ void Creature::Update(uint32 diff)
                     m_regenTimer -= diff;
             }
 
-            if (m_regenTimer != 0)
-               break;
-
-            bool bInCombat = IsInCombat() && (!GetVictim() ||                                        // if IsInCombat() is true and this has no victim
-                             !EnsureVictim()->GetCharmerOrOwnerPlayerOrPlayerItself() ||                // or the victim/owner/charmer is not a player
-                             !EnsureVictim()->GetCharmerOrOwnerPlayerOrPlayerItself()->IsGameMaster()); // or the victim/owner/charmer is not a GameMaster
+            if (m_regenTimer == 0)
+            {
+                bool bInCombat = IsInCombat() && (!GetVictim() ||                                        // if IsInCombat() is true and this has no victim
+                                                  !EnsureVictim()->GetCharmerOrOwnerPlayerOrPlayerItself() ||                // or the victim/owner/charmer is not a player
+                                                  !EnsureVictim()->GetCharmerOrOwnerPlayerOrPlayerItself()->IsGameMaster()); // or the victim/owner/charmer is not a GameMaster
 
-            /*if (m_regenTimer <= diff)
-            {*/
-            if (!IsInEvadeMode() && (!bInCombat || IsPolymorphed())) // regenerate health if not in combat or if polymorphed
-                RegenerateHealth();
+                if (!IsInEvadeMode() && (!bInCombat || IsPolymorphed() || CanNotReachTarget())) // regenerate health if not in combat or if polymorphed
+                    RegenerateHealth();
 
-            if (HasFlag(UNIT_FIELD_FLAGS_2, UNIT_FLAG2_REGENERATE_POWER))
-            {
-                if (getPowerType() == POWER_ENERGY)
-                    Regenerate(POWER_ENERGY);
-                else
-                    RegenerateMana();
+                if (HasFlag(UNIT_FIELD_FLAGS_2, UNIT_FLAG2_REGENERATE_POWER))
+                {
+                    if (getPowerType() == POWER_ENERGY)
+                        Regenerate(POWER_ENERGY);
+                    else
+                        RegenerateMana();
+                }
+                m_regenTimer = CREATURE_REGEN_INTERVAL;
             }
 
-            /*if (!bIsPolymorphed) // only increase the timer if not polymorphed
-                    m_regenTimer += CREATURE_REGEN_INTERVAL - diff;
+            if (CanNotReachTarget() && !IsInEvadeMode() && !GetMap()->IsRaid())
+            {
+                m_cannotReachTimer += diff;
+                if (m_cannotReachTimer >= CREATURE_NOPATH_EVADE_TIME)
+                    if (IsAIEnabled)
+                        AI()->EnterEvadeMode(CreatureAI::EVADE_REASON_NO_PATH);
             }
-            else
-                if (!bIsPolymorphed) // if polymorphed, skip the timer
-                    m_regenTimer -= diff;*/
-            m_regenTimer = CREATURE_REGEN_INTERVAL;
             break;
         }
         default:
@@ -1814,7 +1813,7 @@ SpellInfo const* Creature::reachWithSpellAttack(Unit* victim)
     if (!victim)
         return nullptr;
 
-    for (uint32 i=0; i < CREATURE_MAX_SPELLS; ++i)
+    for (uint32 i=0; i < MAX_CREATURE_SPELLS; ++i)
     {
         if (!m_spells[i])
             continue;
@@ -1862,7 +1861,7 @@ SpellInfo const* Creature::reachWithSpellCure(Unit* victim)
     if (!victim)
         return nullptr;
 
-    for (uint32 i=0; i < CREATURE_MAX_SPELLS; ++i)
+    for (uint32 i=0; i < MAX_CREATURE_SPELLS; ++i)
     {
         if (!m_spells[i])
             continue;
@@ -2307,10 +2306,10 @@ uint32 Creature::GetShieldBlockValue() const                  //dunno mob block
 bool Creature::HasSpell(uint32 spellID) const
 {
     uint8 i;
-    for (i = 0; i < CREATURE_MAX_SPELLS; ++i)
+    for (i = 0; i < MAX_CREATURE_SPELLS; ++i)
         if (spellID == m_spells[i])
             break;
-    return i < CREATURE_MAX_SPELLS;                         //broke before end of iteration of known spells
+    return i < MAX_CREATURE_SPELLS;                         //broke before end of iteration of known spells
 }
 
 time_t Creature::GetRespawnTimeEx() const
diff --git a/src/server/game/Entities/Creature/Creature.h b/src/server/game/Entities/Creature/Creature.h
index c6b19dbb939..71b1d118485 100644
--- a/src/server/game/Entities/Creature/Creature.h
+++ b/src/server/game/Entities/Creature/Creature.h
@@ -67,12 +67,13 @@ enum CreatureFlagsExtra
     CREATURE_FLAG_EXTRA_NO_SKILLGAIN | CREATURE_FLAG_EXTRA_TAUNT_DIMINISH | CREATURE_FLAG_EXTRA_ALL_DIMINISH | \
     CREATURE_FLAG_EXTRA_GUARD | CREATURE_FLAG_EXTRA_IGNORE_PATHFINDING | CREATURE_FLAG_EXTRA_NO_PLAYER_DAMAGE_REQ | CREATURE_FLAG_EXTRA_IMMUNITY_KNOCKBACK)
 
-#define CREATURE_REGEN_INTERVAL 2 * IN_MILLISECONDS
+const uint32 CREATURE_REGEN_INTERVAL = 2 * IN_MILLISECONDS;
+const uint32 CREATURE_NOPATH_EVADE_TIME = 5 * IN_MILLISECONDS;
 
-#define MAX_KILL_CREDIT 2
-#define MAX_CREATURE_MODELS 4
-#define MAX_CREATURE_QUEST_ITEMS 6
-#define CREATURE_MAX_SPELLS 8
+const uint8 MAX_KILL_CREDIT = 2;
+const uint32 MAX_CREATURE_MODELS = 4;
+const uint32 MAX_CREATURE_QUEST_ITEMS = 6;
+const uint32 MAX_CREATURE_SPELLS = 8;
 
 // from `creature_template` table
 struct TC_GAME_API CreatureTemplate
@@ -117,7 +118,7 @@ struct TC_GAME_API CreatureTemplate
     uint32  pickpocketLootId;
     uint32  SkinLootId;
     int32   resistance[MAX_SPELL_SCHOOL];
-    uint32  spells[CREATURE_MAX_SPELLS];
+    uint32  spells[MAX_CREATURE_SPELLS];
     uint32  PetSpellDataId;
     uint32  VehicleId;
     uint32  mingold;
@@ -475,6 +476,7 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         uint8 getLevelForTarget(WorldObject const* target) const override; // overwrite Unit::getLevelForTarget for boss level support
 
         bool IsInEvadeMode() const { return HasUnitState(UNIT_STATE_EVADE); }
+        bool IsEvadingAttacks() const { return IsInEvadeMode() || CanNotReachTarget(); }
 
         bool AIM_Initialize(CreatureAI* ai = NULL);
         void Motion_Initialize();
@@ -566,7 +568,7 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         SpellInfo const* reachWithSpellAttack(Unit* victim);
         SpellInfo const* reachWithSpellCure(Unit* victim);
 
-        uint32 m_spells[CREATURE_MAX_SPELLS];
+        uint32 m_spells[MAX_CREATURE_SPELLS];
 
         bool CanStartAttack(Unit const* u, bool force) const;
         float GetAttackDistance(Unit const* player) const;
@@ -631,6 +633,9 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         virtual uint8 GetPetAutoSpellSize() const { return MAX_SPELL_CHARM; }
         virtual uint32 GetPetAutoSpellOnPos(uint8 pos) const;
 
+        void SetCannotReachTarget(bool cannotReach) { if (cannotReach == m_cannotReachTarget) return; m_cannotReachTarget = cannotReach; m_cannotReachTimer = 0; }
+        bool CanNotReachTarget() const { return m_cannotReachTarget; }
+
         void SetPosition(float x, float y, float z, float o);
         void SetPosition(const Position &pos) { SetPosition(pos.GetPositionX(), pos.GetPositionY(), pos.GetPositionZ(), pos.GetOrientation()); }
 
@@ -718,6 +723,8 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         bool m_AlreadyCallAssistance;
         bool m_AlreadySearchedAssistance;
         bool m_regenHealth;
+        bool m_cannotReachTarget;
+        uint32 m_cannotReachTimer;
         bool m_AI_locked;
 
         SpellSchoolMask m_meleeDamageSchoolMask;
diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index 0af1fc87f6b..4a21a6d0fd7 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -20485,7 +20485,7 @@ void Player::VehicleSpellInitialize()
     data << uint8(0);                                       // Command State
     data << uint16(0x800);                                  // DisableActions (set for all vehicles)
 
-    for (uint32 i = 0; i < CREATURE_MAX_SPELLS; ++i)
+    for (uint32 i = 0; i < MAX_CREATURE_SPELLS; ++i)
     {
         uint32 spellId = vehicle->m_spells[i];
         SpellInfo const* spellInfo = sSpellMgr->GetSpellInfo(spellId);
@@ -20509,7 +20509,7 @@ void Player::VehicleSpellInitialize()
         data << uint32(MAKE_UNIT_ACTION_BUTTON(spellId, i+8));
     }
 
-    for (uint32 i = CREATURE_MAX_SPELLS; i < MAX_SPELL_CONTROL_BAR; ++i)
+    for (uint32 i = MAX_CREATURE_SPELLS; i < MAX_SPELL_CONTROL_BAR; ++i)
         data << uint32(0);
 
     data << uint8(0); // Auras?
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 319b939d899..45577f5cf1c 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -578,7 +578,7 @@ bool Unit::HasBreakableByDamageCrowdControlAura(Unit* excludeCasterChannel) cons
 
 void Unit::DealDamageMods(Unit* victim, uint32 &damage, uint32* absorb)
 {
-    if (!victim || !victim->IsAlive() || victim->HasUnitState(UNIT_STATE_IN_FLIGHT) || (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsInEvadeMode()))
+    if (!victim || !victim->IsAlive() || victim->HasUnitState(UNIT_STATE_IN_FLIGHT) || (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsEvadingAttacks()))
     {
         if (absorb)
             *absorb += damage;
@@ -1120,7 +1120,7 @@ void Unit::DealSpellDamage(SpellNonMeleeDamage* damageInfo, bool durabilityLoss)
     if (!victim)
         return;
 
-    if (!victim->IsAlive() || victim->HasUnitState(UNIT_STATE_IN_FLIGHT) || (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsInEvadeMode()))
+    if (!victim->IsAlive() || victim->HasUnitState(UNIT_STATE_IN_FLIGHT) || (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsEvadingAttacks()))
         return;
 
     SpellInfo const* spellProto = sSpellMgr->GetSpellInfo(damageInfo->SpellID);
@@ -1346,7 +1346,7 @@ void Unit::DealMeleeDamage(CalcDamageInfo* damageInfo, bool durabilityLoss)
 {
     Unit* victim = damageInfo->target;
 
-    if (!victim->IsAlive() || victim->HasUnitState(UNIT_STATE_IN_FLIGHT) || (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsInEvadeMode()))
+    if (!victim->IsAlive() || victim->HasUnitState(UNIT_STATE_IN_FLIGHT) || (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsEvadingAttacks()))
         return;
 
     // Hmmmm dont like this emotes client must by self do all animations
@@ -2044,7 +2044,7 @@ MeleeHitOutcome Unit::RollMeleeOutcomeAgainst(const Unit* victim, WeaponAttackTy
 
 MeleeHitOutcome Unit::RollMeleeOutcomeAgainst (const Unit* victim, WeaponAttackType attType, int32 crit_chance, int32 miss_chance, int32 dodge_chance, int32 parry_chance, int32 block_chance) const
 {
-    if (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsInEvadeMode())
+    if (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsEvadingAttacks())
         return MELEE_HIT_EVADE;
 
     int32 attackerMaxSkillValueForLevel = GetMaxSkillValueForLevel(victim);
@@ -2656,7 +2656,7 @@ SpellMissInfo Unit::SpellHitResult(Unit* victim, SpellInfo const* spellInfo, boo
         return SPELL_MISS_NONE;
 
     // Return evade for units in evade mode
-    if (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsInEvadeMode())
+    if (victim->GetTypeId() == TYPEID_UNIT && victim->ToCreature()->IsEvadingAttacks())
         return SPELL_MISS_EVADE;
 
     // Try victim reflect spell
@@ -8990,7 +8990,7 @@ bool Unit::Attack(Unit* victim, bool meleeAttack)
     }
     else
     {
-        if (victim->ToCreature()->IsInEvadeMode())
+        if (victim->ToCreature()->IsEvadingAttacks())
             return false;
     }
 
@@ -13887,7 +13887,7 @@ void CharmInfo::InitPossessCreateSpells()
                 break;
         }
 
-        for (uint8 i = 0; i < CREATURE_MAX_SPELLS; ++i)
+        for (uint8 i = 0; i < MAX_CREATURE_SPELLS; ++i)
         {
             uint32 spellId = _unit->ToCreature()->m_spells[i];
             SpellInfo const* spellInfo = sSpellMgr->GetSpellInfo(spellId);