Add Has Tag decorator

Source/Engine/AI/BehaviorKnowledgeSelector.h

@@ -3,6 +3,7 @@
 #pragma once
 
 #include "Engine/Core/Types/Variant.h"
+#include "Engine/Core/Types/VariantValueCast.h"
 #include "Engine/Serialization/SerializationFwd.h"
 
 class BehaviorKnowledge;
@@ -70,7 +71,7 @@ API_STRUCT(InBuild, Template, MarshalAs=StringAnsi) struct FLAXENGINE_API Behavi
     // Gets the selected knowledge value (typed).
     FORCE_INLINE T Get(BehaviorKnowledge* knowledge)
     {
-        return (T)BehaviorKnowledgeSelectorAny::Get(knowledge);
+        return TVariantValueCast<T>::Cast(BehaviorKnowledgeSelectorAny::Get(knowledge));
     }
 
     // Tries to get the selected knowledge value (typed). Returns true if got value, otherwise false.
@@ -79,7 +80,7 @@ API_STRUCT(InBuild, Template, MarshalAs=StringAnsi) struct FLAXENGINE_API Behavi
         Variant variant;
         if (BehaviorKnowledgeSelectorAny::TryGet(knowledge, variant))
         {
-            value = (T)variant;
+            value = TVariantValueCast<T>::Cast(variant);
             return true;
         }
         return false;

Source/Engine/AI/BehaviorTreeNodes.cpp

@@ -8,6 +8,7 @@
 #if USE_CSHARP
 #include "Engine/Scripting/ManagedCLR/MClass.h"
 #endif
+#include "Engine/Level/Actor.h"
 #include "Engine/Serialization/Serialization.h"
 
 bool IsAssignableFrom(const StringAnsiView& to, const StringAnsiView& from)
@@ -445,3 +446,13 @@ bool BehaviorTreeKnowledgeValuesConditionalDecorator::CanUpdate(const BehaviorUp
 {
     return BehaviorKnowledge::CompareValues((float)ValueA.Get(context.Knowledge), (float)ValueB.Get(context.Knowledge), Comparison);
 }
+
+bool BehaviorTreeHasTagDecorator::CanUpdate(const BehaviorUpdateContext& context)
+{
+    bool result = false;
+    ::Actor* actor;
+    if (Actor.TryGet(context.Knowledge, actor) && actor)
+        result = actor->HasTag(Tag);
+    result ^= Invert;
+    return result;
+}

Source/Engine/AI/BehaviorTreeNodes.h

@@ -8,6 +8,9 @@
 #include "Engine/Core/Collections/Array.h"
 #include "Engine/Core/Collections/BitArray.h"
 #include "Engine/Content/AssetReference.h"
+#include "Engine/Level/Tags.h"
+
+class Actor;
 
 /// <summary>
 /// Base class for compound Behavior Tree nodes that composite child nodes.
@@ -342,3 +345,28 @@ public:
     // [BehaviorTreeNode]
     bool CanUpdate(const BehaviorUpdateContext& context) override;
 };
+
+/// <summary>
+/// Checks if certain actor (from knowledge) has a given tag assigned.
+/// </summary>
+API_CLASS(Sealed) class FLAXENGINE_API BehaviorTreeHasTagDecorator : public BehaviorTreeDecorator
+{
+    DECLARE_SCRIPTING_TYPE_WITH_CONSTRUCTOR_IMPL(BehaviorTreeHasTagDecorator, BehaviorTreeDecorator);
+    API_AUTO_SERIALIZATION();
+
+    // The actor value from behavior's knowledge (blackboard, goal or sensor) to check against tag ownership.
+    API_FIELD(Attributes="EditorOrder(0)")
+    BehaviorKnowledgeSelector<Actor*> Actor;
+
+    // The tag to check.
+    API_FIELD(Attributes="EditorOrder(10)")
+    Tag Tag;
+
+    // If checked, inverts condition - checks if actor doesn't have a tag.
+    API_FIELD(Attributes="EditorOrder(20)")
+    bool Invert = false;
+
+public:
+    // [BehaviorTreeNode]
+    bool CanUpdate(const BehaviorUpdateContext& context) override;
+};

Source/Engine/Core/Types/VariantValueCast.h

@@ -0,0 +1,25 @@
+// Copyright (c) 2012-2023 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#include "Engine/Core/Types/Variant.h"
+#include "Engine/Core/Templates.h"
+
+// Helper utility to read Variant value with automatic casting to the template type (eg. cast ScriptingObject* to Actor*).
+template<typename T, typename Enable = void>
+struct TVariantValueCast
+{
+    FORCE_INLINE static T Cast(const Variant& v)
+    {
+        return (T)v;
+    }
+};
+
+template<typename T>
+struct TVariantValueCast<T*, typename TEnableIf<TIsBaseOf<class ScriptingObject, T>::Value>::Type>
+{
+    FORCE_INLINE static T* Cast(const Variant& v)
+    {
+        return ScriptingObject::Cast<T>((ScriptingObject*)v);
+    }
+};