Add Invert, ForceSuccess, ForceFailed and Loop decorators to BT

Source/Engine/AI/BehaviorTreeNodes.cpp

@@ -312,3 +312,52 @@ BehaviorUpdateResult BehaviorTreeForceFinishNode::Update(BehaviorUpdateContext c
     context.Behavior->StopLogic(Result);
     return Result;
 }
+
+void BehaviorTreeInvertDecorator::PostUpdate(BehaviorUpdateContext context, BehaviorUpdateResult& result)
+{
+    if (result == BehaviorUpdateResult::Success)
+        result = BehaviorUpdateResult::Failed;
+    else if (result == BehaviorUpdateResult::Failed)
+        result = BehaviorUpdateResult::Success;
+}
+
+void BehaviorTreeForceSuccessDecorator::PostUpdate(BehaviorUpdateContext context, BehaviorUpdateResult& result)
+{
+    if (result != BehaviorUpdateResult::Running)
+        result = BehaviorUpdateResult::Success;
+}
+
+void BehaviorTreeForceFailedDecorator::PostUpdate(BehaviorUpdateContext context, BehaviorUpdateResult& result)
+{
+    if (result != BehaviorUpdateResult::Running)
+        result = BehaviorUpdateResult::Failed;
+}
+
+int32 BehaviorTreeLoopDecorator::GetStateSize() const
+{
+    return sizeof(State);
+}
+
+void BehaviorTreeLoopDecorator::InitState(Behavior* behavior, void* memory)
+{
+    auto state = GetState<State>(memory);
+    if (!LoopCountSelector.TryGet(behavior->GetKnowledge(), state->Loops))
+        state->Loops = LoopCount;
+}
+
+void BehaviorTreeLoopDecorator::PostUpdate(BehaviorUpdateContext context, BehaviorUpdateResult& result)
+{
+    // Continue looping only if node succeeds
+    if (result == BehaviorUpdateResult::Success)
+    {
+        auto state = GetState<State>(context.Memory);
+        state->Loops--;
+        if (state->Loops > 0)
+        {
+            // Keep running in a loop but reset node's state (preserve decorators state including Loops counter)
+            result = BehaviorUpdateResult::Running;
+            _parent->BecomeIrrelevant(context, true);
+            _parent->BecomeRelevant(context);
+        }
+    }
+}

Source/Engine/AI/BehaviorTreeNodes.h

@@ -162,3 +162,67 @@ public:
     // [BehaviorTreeNode]
     BehaviorUpdateResult Update(BehaviorUpdateContext context) override;
 };
+
+/// <summary>
+/// Inverts node's result - fails if node succeeded or succeeds if node failed.
+/// </summary>
+API_CLASS(Sealed) class FLAXENGINE_API BehaviorTreeInvertDecorator : public BehaviorTreeDecorator
+{
+    DECLARE_SCRIPTING_TYPE_WITH_CONSTRUCTOR_IMPL(BehaviorTreeInvertDecorator, BehaviorTreeDecorator);
+
+public:
+    // [BehaviorTreeNode]
+    void PostUpdate(BehaviorUpdateContext context, BehaviorUpdateResult& result) override;
+};
+
+/// <summary>
+/// Forces node to success - even if it failed.
+/// </summary>
+API_CLASS(Sealed) class FLAXENGINE_API BehaviorTreeForceSuccessDecorator : public BehaviorTreeDecorator
+{
+    DECLARE_SCRIPTING_TYPE_WITH_CONSTRUCTOR_IMPL(BehaviorTreeForceSuccessDecorator, BehaviorTreeDecorator);
+
+public:
+    // [BehaviorTreeNode]
+    void PostUpdate(BehaviorUpdateContext context, BehaviorUpdateResult& result) override;
+};
+
+/// <summary>
+/// Forces node to fail - even if it succeeded.
+/// </summary>
+API_CLASS(Sealed) class FLAXENGINE_API BehaviorTreeForceFailedDecorator : public BehaviorTreeDecorator
+{
+    DECLARE_SCRIPTING_TYPE_WITH_CONSTRUCTOR_IMPL(BehaviorTreeForceFailedDecorator, BehaviorTreeDecorator);
+
+public:
+    // [BehaviorTreeNode]
+    void PostUpdate(BehaviorUpdateContext context, BehaviorUpdateResult& result) override;
+};
+
+/// <summary>
+/// Loops node execution multiple times as long as it doesn't fail. Returns the last iteration result.
+/// </summary>
+API_CLASS(Sealed) class FLAXENGINE_API BehaviorTreeLoopDecorator : public BehaviorTreeDecorator
+{
+    DECLARE_SCRIPTING_TYPE_WITH_CONSTRUCTOR_IMPL(BehaviorTreeLoopDecorator, BehaviorTreeDecorator);
+    API_AUTO_SERIALIZATION();
+
+    // Amount of times to execute the node. Unused if LoopCountSelector is used.
+    API_FIELD(Attributes="EditorOrder(10), Limit(0)")
+    int32 LoopCount = 3;
+
+    // Amount of times to execute the node from behavior's knowledge (blackboard, goal or sensor). If set, overrides LoopCount.
+    API_FIELD(Attributes="EditorOrder(20)")
+    BehaviorKnowledgeSelector<int32> LoopCountSelector;
+
+public:
+    // [BehaviorTreeNode]
+    int32 GetStateSize() const override;
+    void InitState(Behavior* behavior, void* memory) override;
+    void PostUpdate(BehaviorUpdateContext context, BehaviorUpdateResult& result) override;
+
+    struct State
+    {
+        int32 Loops;
+    };
+};