Core/AI: initial support for monster sparring (#17673)

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

@@ -1918,6 +1918,50 @@ void Unit::AttackerStateUpdate (Unit* victim, WeaponAttackType attType, bool ext
     }
 }
 
+void Unit::FakeAttackerStateUpdate(Unit* victim, WeaponAttackType attType /*= BASE_ATTACK*/)
+{
+    if (HasUnitState(UNIT_STATE_CANNOT_AUTOATTACK) || HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_PACIFIED))
+        return;
+
+    if (!victim->IsAlive())
+        return;
+
+    if ((attType == BASE_ATTACK || attType == OFF_ATTACK) && !IsWithinLOSInMap(victim))
+        return;
+
+    CombatStart(victim);
+    RemoveAurasWithInterruptFlags(AURA_INTERRUPT_FLAG_MELEE_ATTACK);
+
+    if (attType != BASE_ATTACK && attType != OFF_ATTACK)
+        return;                                             // ignore ranged case
+
+    if (GetTypeId() == TYPEID_UNIT && !HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_PLAYER_CONTROLLED))
+        SetFacingToObject(victim); // update client side facing to face the target (prevents visual glitches when casting untargeted spells)
+
+    CalcDamageInfo damageInfo;
+    damageInfo.attacker = this;
+    damageInfo.target = victim;
+    damageInfo.damageSchoolMask = GetMeleeDamageSchoolMask();
+    damageInfo.attackType = attType;
+    damageInfo.damage = 0;
+    damageInfo.cleanDamage = 0;
+    damageInfo.absorb = 0;
+    damageInfo.resist = 0;
+    damageInfo.blocked_amount = 0;
+
+    damageInfo.TargetState = VICTIMSTATE_HIT;
+    damageInfo.HitInfo = HITINFO_AFFECTS_VICTIM | HITINFO_NORMALSWING | HITINFO_FAKE_DAMAGE;
+    if (attType == OFF_ATTACK)
+        damageInfo.HitInfo |= HITINFO_OFFHAND;
+
+    damageInfo.procAttacker = PROC_FLAG_NONE;
+    damageInfo.procVictim = PROC_FLAG_NONE;
+    damageInfo.procEx = PROC_EX_NONE;
+    damageInfo.hitOutCome = MELEE_HIT_NORMAL;
+
+    SendAttackStateUpdate(&damageInfo);
+}
+
 void Unit::HandleProcExtraAttackFor(Unit* victim)
 {
     while (m_extraAttacks)
@@ -5022,8 +5066,8 @@ void Unit::SendAttackStateUpdate(CalcDamageInfo* damageInfo)
 {
     TC_LOG_DEBUG("entities.unit", "WORLD: Sending SMSG_ATTACKERSTATEUPDATE");
 
-    uint32 count = 1;
-    size_t maxsize = 4+5+5+4+4+1+4+4+4+4+4+1+4+4+4+4+4*12;
+    uint32 const count = 1;
+    size_t const maxsize = 4+5+5+4+4+1+4+4+4+4+4+1+4+4+4+4+4*12;
     WorldPacket data(SMSG_ATTACKERSTATEUPDATE, maxsize);    // we guess size
     data << uint32(damageInfo->HitInfo);
     data << damageInfo->attacker->GetPackGUID();