feat: Adds monster ability groups with weights (#1267)

Projects/UOContent/Mobiles/Abilities/MonsterAbilityGroup.cs

@@ -0,0 +1,155 @@
+using System;
+using Server.Random;
+using WeightedMonsterAbility = Server.Random.WeightedValue<Server.Mobiles.MonsterAbility>;
+
+namespace Server.Mobiles;
+
+public class MonsterAbilityGroup : MonsterAbility
+{
+    private WeightedMonsterAbility[] _weightedAbilities;
+    private WeightedMonsterAbility[] _availableToTrigger;
+    private int _availableToTriggerCount;
+    private MonsterAbilityTrigger _triggers;
+
+    public MonsterAbilityGroup(params WeightedMonsterAbility[] weightedAbilities)
+    {
+        _weightedAbilities = weightedAbilities;
+        _availableToTrigger = new WeightedMonsterAbility[weightedAbilities.Length];
+
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            var weightedAbility = _weightedAbilities[i];
+            _triggers |= weightedAbility.Value.AbilityTrigger;
+        }
+    }
+
+    public override MonsterAbilityTrigger AbilityTrigger => _triggers;
+
+    public bool HasAbility(MonsterAbility ability)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            if (_weightedAbilities[i].Value == ability)
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    // Note: Does not get an ability randomly by weight
+    // This is used for passives or lookups
+    public MonsterAbility GetAbilityWithType(MonsterAbilityType type)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            var ability = _weightedAbilities[i].Value;
+            if (ability.AbilityType == type)
+            {
+                return ability;
+            }
+        }
+
+        return null;
+    }
+
+    public override bool CanTrigger(BaseCreature source, MonsterAbilityTrigger trigger)
+    {
+        if (!base.CanTrigger(source, trigger))
+        {
+            return false;
+        }
+
+        _availableToTriggerCount = 0;
+
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            var weightedAbility = _weightedAbilities[i];
+            if (weightedAbility.Value.WillTrigger(trigger) && weightedAbility.Value.CanTrigger(source, trigger))
+            {
+                _availableToTrigger[_availableToTriggerCount++] = weightedAbility;
+            }
+        }
+
+        return _availableToTriggerCount > 0;
+    }
+
+    // Note: Trigger will choose an ability at random by weight
+    public override void Trigger(MonsterAbilityTrigger trigger, BaseCreature source, Mobile target)
+    {
+        if (_availableToTriggerCount <= 0)
+        {
+            return;
+        }
+
+        var slice = new ReadOnlySpan<WeightedValue<MonsterAbility>>(_availableToTrigger, 0, _availableToTriggerCount);
+        var chosenAbility = slice.RandomWeightedElement().Value;
+
+        // Just in case?
+        if (chosenAbility == null)
+        {
+            return;
+        }
+
+        base.Trigger(trigger, source, target);
+        chosenAbility.Trigger(trigger, source, target);
+        _availableToTriggerCount = 0; // Just in case trigger is called without CanTrigger
+    }
+
+    public override void AlterMeleeDamageFrom(BaseCreature source, Mobile target, ref int damage)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            _weightedAbilities[i].Value.AlterMeleeDamageFrom(source, target, ref damage);
+        }
+    }
+
+    public override void AlterMeleeDamageTo(BaseCreature source, Mobile target, ref int damage)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            _weightedAbilities[i].Value.AlterMeleeDamageTo(source, target, ref damage);
+        }
+    }
+
+    public override void AlterSpellDamageScalarFrom(BaseCreature source, Mobile target, ref double scalar)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            _weightedAbilities[i].Value.AlterSpellDamageScalarFrom(source, target, ref scalar);
+        }
+    }
+
+    public override void AlterSpellDamageScalarTo(BaseCreature source, Mobile target, ref double scalar)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            _weightedAbilities[i].Value.AlterSpellDamageScalarTo(source, target, ref scalar);
+        }
+    }
+
+    public override void AlterSpellDamageFrom(BaseCreature source, Mobile target, ref int damage)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            _weightedAbilities[i].Value.AlterSpellDamageFrom(source, target, ref damage);
+        }
+    }
+
+    public override void AlterSpellDamageTo(BaseCreature source, Mobile target, ref int damage)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            _weightedAbilities[i].Value.AlterSpellDamageTo(source, target, ref damage);
+        }
+    }
+
+    public override void Move(BaseCreature creature, Direction d)
+    {
+        for (var i = 0; i < _weightedAbilities.Length; i++)
+        {
+            _weightedAbilities[i].Value.Move(creature, d);
+        }
+    }
+}

Projects/UOContent/Mobiles/BaseCreature.cs

@@ -1130,7 +1130,15 @@ namespace Server.Mobiles
             for (var i = 0; i < abilities.Length; i++)
             {
                 var ability = abilities[i];
-                if (ability.AbilityType == type)
+                if (ability is MonsterAbilityGroup group)
+                {
+                    ability = group.GetAbilityWithType(type);
+                    if (ability != null)
+                    {
+                        return ability;
+                    }
+                }
+                else if (ability.AbilityType == type)
                 {
                     return ability;
                 }
@@ -1141,6 +1149,11 @@ namespace Server.Mobiles
 
         public virtual bool HasAbility(MonsterAbility ability)
         {
+            if (ability == null)
+            {
+                return false;
+            }
+
             var abilities = GetMonsterAbilities();
 
             if (abilities == null)
@@ -1150,7 +1163,7 @@ namespace Server.Mobiles
 
             for (var i = 0; i < abilities.Length; i++)
             {
-                if (abilities[i] == ability)
+                if (abilities[i] == ability || (ability as MonsterAbilityGroup)?.HasAbility(ability) == true)
                 {
                     return true;
                 }
@@ -4290,7 +4303,6 @@ namespace Server.Mobiles
 
         public virtual void OnActionCombat()
         {
-            TriggerAbility(MonsterAbilityTrigger.CombatAction, null);
         }
 
         public virtual void OnActionGuard()