Core/Spells: Prevent creatures from being able to cast all their spel…

…ls while moving

Closes TrinityCore#26137

(cherry picked from commit f80f931)

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

@@ -3246,21 +3246,10 @@ void Creature::DoNotReacquireSpellFocusTarget()
 
 bool Creature::IsMovementPreventedByCasting() const
 {
-    // first check if currently a movement allowed channel is active and we're not casting
-    if (Spell* spell = m_currentSpells[CURRENT_CHANNELED_SPELL])
-    {
-        if (spell->getState() != SPELL_STATE_FINISHED && spell->IsChannelActive())
-            if (spell->GetSpellInfo()->IsMoveAllowedChannel())
-                return false;
-    }
-
-    if (HasSpellFocus())
-        return true;
-
-    if (HasUnitState(UNIT_STATE_CASTING))
-        return true;
+    if (!Unit::IsMovementPreventedByCasting() && !HasSpellFocus())
+        return false;
 
-    return false;
+    return true;
 }
 
 void Creature::StartPickPocketRefillTimer()

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

@@ -3123,6 +3123,11 @@ bool Unit::IsMovementPreventedByCasting() const
     if (!HasUnitState(UNIT_STATE_CASTING))
         return false;
 
+    if (Spell* spell = m_currentSpells[CURRENT_GENERIC_SPELL])
+        if (spell->getState() == SPELL_STATE_FINISHED ||
+            !(spell->m_spellInfo->InterruptFlags & SPELL_INTERRUPT_FLAG_MOVEMENT))
+            return false;
+
     // channeled spells during channel stage (after the initial cast timer) allow movement with a specific spell attribute
     if (Spell* spell = m_currentSpells[CURRENT_CHANNELED_SPELL])
         if (spell->getState() != SPELL_STATE_FINISHED && spell->IsChannelActive())

src/server/game/Movement/MovementDefines.h

@@ -47,6 +47,21 @@ enum MovementGeneratorType : uint8
     MAX_MOTION_TYPE                          // SKIP
 };
 
+constexpr bool CanStopMovementForSpellCasting(MovementGeneratorType type)
+{
+    // MovementGenerators that don't check Unit::IsMovementPreventedByCasting
+    switch (type)
+    {
+        case HOME_MOTION_TYPE:
+        case FLIGHT_MOTION_TYPE:
+        case EFFECT_MOTION_TYPE:    // knockbacks, jumps, falling, land/takeoff transitions
+            return false;
+        default:
+            break;
+    }
+    return true;
+}
+
 enum MovementGeneratorMode : uint8
 {
     MOTION_MODE_DEFAULT = 0,

src/server/game/Spells/Spell.cpp

@@ -36,6 +36,7 @@
 #include "Item.h"
 #include "Log.h"
 #include "LootMgr.h"
+#include "MotionMaster.h"
 #include "ObjectAccessor.h"
 #include "ObjectMgr.h"
 #include "Opcodes.h"
@@ -3148,19 +3149,9 @@ SpellCastResult Spell::prepare(SpellCastTargets const& targets, AuraEffect const
     else
         m_casttime = m_spellInfo->CalcCastTime(this);
 
-    // don't allow channeled spells / spells with cast time to be cast while moving
-    // exception are only channeled spells that have no casttime and SPELL_ATTR5_CAN_CHANNEL_WHEN_MOVING
-    // (even if they are interrupted on moving, spells with almost immediate effect get to have their effect processed before movement interrupter kicks in)
-    if ((m_spellInfo->IsChanneled() || m_casttime) && m_caster->GetTypeId() == TYPEID_PLAYER && !(m_caster->ToPlayer()->IsCharmed() && m_caster->ToPlayer()->GetCharmerGUID().IsCreature()) && m_caster->ToPlayer()->isMoving() && (m_spellInfo->InterruptFlags & SPELL_INTERRUPT_FLAG_MOVEMENT))
-    {
-        // 1. Has casttime, 2. Or doesn't have flag to allow movement during channel
-        if (m_casttime || !m_spellInfo->IsMoveAllowedChannel())
-        {
-            SendCastResult(SPELL_FAILED_MOVING);
-            finish(false);
-            return SPELL_FAILED_MOVING;
-        }
-    }
+    SpellCastResult movementResult = SPELL_CAST_OK;
+    if (m_caster->IsUnit() && m_caster->ToUnit()->isMoving())
+        movementResult = CheckMovement();
 
     // Creatures focus their target when possible
     if (m_casttime && m_caster->IsCreature() && !m_spellInfo->IsNextMeleeSwingSpell() && !IsAutoRepeat() && !m_caster->ToUnit()->HasUnitFlag(UNIT_FLAG_POSSESSED))
@@ -3173,6 +3164,24 @@ SpellCastResult Spell::prepare(SpellCastTargets const& targets, AuraEffect const
             m_caster->ToCreature()->SetSpellFocus(this, nullptr);
     }
 
+    if (movementResult != SPELL_CAST_OK)
+    {
+        if (m_caster->ToUnit()->IsControlledByPlayer() || !CanStopMovementForSpellCasting(m_caster->ToUnit()->GetMotionMaster()->GetCurrentMovementGeneratorType()))
+        {
+            SendCastResult(movementResult);
+            finish(movementResult);
+            return movementResult;
+        }
+        else
+        {
+            // Creatures (not controlled) give priority to spell casting over movement.
+            // We assume that the casting is always valid and the current movement
+            // is stopped immediately (because spells are updated before movement, so next Unit::Update would cancel the spell before stopping movement)
+            // and future attempts are stopped by by Unit::IsMovementPreventedByCasting in movement generators to prevent casting interruption.
+            m_caster->ToUnit()->StopMoving();
+        }
+    }
+
     // set timer base at cast time
     ReSetTimer();
 
@@ -3805,21 +3814,9 @@ void Spell::update(uint32 difftime)
         return;
     }
 
-    // check if the player caster has moved before the spell finished
-    if (m_caster->GetTypeId() == TYPEID_PLAYER && m_timer != 0 &&
-        m_caster->ToPlayer()->isMoving() && m_spellInfo->InterruptFlags & SPELL_INTERRUPT_FLAG_MOVEMENT &&
-        (!m_spellInfo->HasEffect(SPELL_EFFECT_STUCK) || !m_caster->ToPlayer()->HasUnitMovementFlag(MOVEMENTFLAG_FALLING_FAR)))
-    {
-        // don't cancel for melee, autorepeat, triggered and instant spells
-        if (!m_spellInfo->IsNextMeleeSwingSpell() && !IsAutoRepeat() && !IsTriggered() && !(IsChannelActive() && m_spellInfo->IsMoveAllowedChannel()))
-        {
-            // if charmed by creature, trust the AI not to cheat and allow the cast to proceed
-            // @todo this is a hack, "creature" movesplines don't differentiate turning/moving right now
-            // however, checking what type of movement the spline is for every single spline would be really expensive
-            if (!m_caster->ToPlayer()->GetCharmerGUID().IsCreature())
-                cancel();
-        }
-    }
+    // check if the unit caster has moved before the spell finished
+    if (m_timer != 0 && m_caster->IsUnit() && m_caster->ToUnit()->isMoving() && CheckMovement() != SPELL_CAST_OK)
+        cancel();
 
     switch (m_spellState)
     {
@@ -6396,6 +6393,24 @@ int32 Spell::CalculateDamage(SpellEffectInfo const& spellEffectInfo) const
     return m_caster->CalculateSpellDamage(spellEffectInfo, m_spellValue->EffectBasePoints + spellEffectInfo.EffectIndex);
 }
 
+SpellCastResult Spell::CheckMovement() const
+{
+    if (IsTriggered())
+        return SPELL_CAST_OK;
+
+        if (getState() == SPELL_STATE_PREPARING)
+        {
+            if (m_casttime > 0)
+                if (m_spellInfo->InterruptFlags & SPELL_INTERRUPT_FLAG_MOVEMENT)
+                    return SPELL_FAILED_MOVING;
+        }
+        else if (getState() == SPELL_STATE_CASTING)
+            if (!m_spellInfo->IsMoveAllowedChannel())
+                return SPELL_FAILED_MOVING;
+
+    return SPELL_CAST_OK;
+}
+
 bool Spell::CanAutoCast(Unit* target)
 {
     if (!target)

src/server/game/Spells/Spell.h

@@ -338,6 +338,7 @@ class TC_GAME_API Spell
         SpellCastResult CheckPower() const;
         SpellCastResult CheckRuneCost(uint32 runeCostID) const;
         SpellCastResult CheckCasterAuras(uint32* param1) const;
+        SpellCastResult CheckMovement() const;
 
         bool CheckSpellCancelsAuraEffect(AuraType auraType, uint32* param1) const;
         bool CheckSpellCancelsCharm(uint32* param1) const;

src/server/game/Spells/SpellEffects.cpp

@@ -4309,10 +4309,6 @@ void Spell::EffectKnockBack()
     if (unitTarget->HasUnitState(UNIT_STATE_ROOT))
         return;
 
-    // Instantly interrupt non melee spells being cast
-    if (unitTarget->IsNonMeleeSpellCast(true))
-        unitTarget->InterruptNonMeleeSpells(true);
-
     float ratio = 0.1f;
     float speedxy = float(effectInfo->MiscValue) * ratio;
     float speedz = float(damage) * ratio;