Merge pull request #339 from MUnique/performance-ai

Optimization for the monster/npc intelligence
MUnique · Apr 3, 2023 · b8ec349 · b8ec349
2 parents f59df34 + 7d19282
commit b8ec349
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Showing 7 changed files with 106 additions and 10 deletions.
diff --git a/src/GameLogic/INpcIntelligence.cs b/src/GameLogic/INpcIntelligence.cs
@@ -26,4 +26,9 @@ public interface INpcIntelligence
     /// Starts the actions.
     /// </summary>
     void Start();
+
+    /// <summary>
+    /// Pauses the actions.
+    /// </summary>
+    void Pause();
 }
diff --git a/src/GameLogic/NPC/BasicMonsterIntelligence.cs b/src/GameLogic/NPC/BasicMonsterIntelligence.cs
@@ -45,18 +45,18 @@ public Monster Monster
     /// </summary>
     protected IAttackable? CurrentTarget { get; private set; }
 
-    private async ValueTask<bool> IsObservedByAttackerAsync()
+    /// <inheritdoc/>
+    public void Start()
     {
-        using var readerLock = await this.Monster.ObserverLock.ReaderLockAsync();
-        return this.Monster.Observers.OfType<IAttacker>().Any();
+        var startDelay = this.Npc.Definition.AttackDelay + TimeSpan.FromMilliseconds(Rand.NextInt(0, 1000));
+        this._aiTimer ??= new Timer(_ => this.SafeTick(), null, startDelay, this.Npc.Definition.AttackDelay);
     }
 
     /// <inheritdoc/>
-    public void Start()
+    public void Pause()
     {
-        TimeSpan randomized = this.Npc.Definition.AttackDelay + TimeSpan.FromMilliseconds(Rand.NextInt(0, 1000));
-        // TODO: Optimize this: start timer when first observer is added. stop timer when last observer is removed.
-        this._aiTimer = new Timer(_ => this.SafeTick(), null, randomized, this.Npc.Definition.AttackDelay);
+        this._aiTimer?.Dispose();
+        this._aiTimer = null;
     }
 
     /// <inheritdoc/>
@@ -156,6 +156,7 @@ private async ValueTask TickAsync()
     {
         if (!this.Monster.IsAlive)
         {
+            this.CurrentTarget = null;
             return;
         }
 
@@ -235,4 +236,10 @@ private async ValueTask TickAsync()
         // we move around randomly, so the monster does not look dead when watched from distance.
         await this.Monster.RandomMoveAsync().ConfigureAwait(false);
     }
+
+    private async ValueTask<bool> IsObservedByAttackerAsync()
+    {
+        using var readerLock = await this.Monster.ObserverLock.ReaderLockAsync();
+        return this.Monster.Observers.OfType<IAttacker>().Any();
+    }
 }
diff --git a/src/GameLogic/NPC/Monster.cs b/src/GameLogic/NPC/Monster.cs
@@ -62,7 +62,6 @@ public Monster(MonsterSpawnArea spawnInfo, MonsterDefinition stats, GameMap map,
         (this._skillPowerUp, this._skillPowerUpDuration, this._skillPowerUpTarget) = this.CreateMagicEffectPowerUp();
 
         this._intelligence.Npc = this;
-        this._intelligence.Start();
     }
 
     /// <summary>
@@ -234,6 +233,20 @@ internal async ValueTask RandomMoveAsync()
         }
     }
 
+    /// <inheritdoc/>
+    protected override void OnFirstObserverAdded()
+    {
+        base.OnFirstObserverAdded();
+        this._intelligence.Start();
+    }
+
+    /// <inheritdoc/>
+    protected override void OnLastObserverRemoved()
+    {
+        base.OnLastObserverRemoved();
+        this._intelligence.Pause();
+    }
+
     /// <inheritdoc/>
     protected override void Dispose(bool managed)
     {

diff --git a/src/GameLogic/NPC/NonPlayerCharacter.cs b/src/GameLogic/NPC/NonPlayerCharacter.cs
@@ -96,13 +96,25 @@ public async ValueTask AddObserverAsync(IWorldObserver observer)
     {
         using var writerLock = await this.ObserverLock.WriterLockAsync();
         this.Observers.Add(observer);
+        if (this.Observers.Count == 1)
+        {
+            this.OnFirstObserverAdded();
+        }
+
+        this.OnObserverAdded();
     }
 
     /// <inheritdoc/>
     public async ValueTask RemoveObserverAsync(IWorldObserver observer)
     {
         using var writerLock = await this.ObserverLock.WriterLockAsync();
         this.Observers.Remove(observer);
+        if (this.Observers.Count == 0)
+        {
+            this.OnLastObserverRemoved();
+        }
+
+        this.OnObserverRemoved();
     }
 
     /// <inheritdoc/>
@@ -111,6 +123,38 @@ public override string ToString()
         return $"{this.Definition.Designation} - Id: {this.Id} - Position: {this.Position}";
     }
 
+    /// <summary>
+    /// Called when an observer has been added.
+    /// </summary>
+    protected virtual void OnObserverAdded()
+    {
+        // can be overwritten.
+    }
+
+    /// <summary>
+    /// Called when an observer has been removed.
+    /// </summary>
+    protected virtual void OnObserverRemoved()
+    {
+        // can be overwritten.
+    }
+
+    /// <summary>
+    /// Called when the first observer has been added.
+    /// </summary>
+    protected virtual void OnFirstObserverAdded()
+    {
+        // can be overwritten.
+    }
+
+    /// <summary>
+    /// Called when the last observer has been removed.
+    /// </summary>
+    protected virtual void OnLastObserverRemoved()
+    {
+        // can be overwritten.
+    }
+
     /// <inheritdoc />
     protected override async ValueTask DisposeAsyncCore()
     {

diff --git a/src/GameLogic/NPC/NullMonsterIntelligence.cs b/src/GameLogic/NPC/NullMonsterIntelligence.cs
@@ -29,4 +29,10 @@ public void Start()
     {
         // do nothing
     }
+
+    /// <inheritdoc />
+    public void Pause()
+    {
+        // do nothing
+    }
 }
diff --git a/src/GameLogic/NPC/Trap.cs b/src/GameLogic/NPC/Trap.cs
@@ -29,7 +29,6 @@ public Trap(MonsterSpawnArea spawnInfo, MonsterDefinition stats, GameMap map, IN
         this.Attributes = new TrapAttributeHolder(this);
         this._intelligence = trapIntelligence;
         this._intelligence.Npc = this;
-        this._intelligence.Start();
     }
 
     /// <inheritdoc/>
@@ -51,6 +50,20 @@ public async Task AttackAsync(IAttackable player)
         await this.ForEachWorldObserverAsync<IShowAnimationPlugIn>(p => p.ShowAnimationAsync(this, TrapAttackAnimation, player, this.Rotation), true).ConfigureAwait(false);
     }
 
+    /// <inheritdoc/>
+    protected override void OnFirstObserverAdded()
+    {
+        base.OnFirstObserverAdded();
+        this._intelligence.Start();
+    }
+
+    /// <inheritdoc/>
+    protected override void OnLastObserverRemoved()
+    {
+        base.OnLastObserverRemoved();
+        this._intelligence.Pause();
+    }
+
     /// <inheritdoc/>
     protected override void Dispose(bool managed)
     {

diff --git a/src/GameLogic/NPC/TrapIntelligenceBase.cs b/src/GameLogic/NPC/TrapIntelligenceBase.cs
@@ -71,7 +71,15 @@ public void RegisterHit(IAttacker attacker)
     /// <inheritdoc/>
     public void Start()
     {
-        this._aiTimer = new Timer(state => this.SafeTick(), null, this.Trap.Definition.AttackDelay, this.Trap.Definition.AttackDelay);
+        var startDelay = this.Npc.Definition.AttackDelay + TimeSpan.FromMilliseconds(Rand.NextInt(0, 1000));
+        this._aiTimer ??= new Timer(_ => this.SafeTick(), null, startDelay, this.Npc.Definition.AttackDelay);
+    }
+
+    /// <inheritdoc/>
+    public void Pause()
+    {
+        this._aiTimer?.Dispose();
+        this._aiTimer = null;
     }
 
     /// <inheritdoc/>