Add GetDebugInfo to BT nodes for debugging

Source/Editor/Surface/Archetypes/BehaviorTree.cs

@@ -29,6 +29,8 @@ namespace FlaxEditor.Surface.Archetypes
             protected const float DecoratorsMarginX = 5.0f;
             protected const float DecoratorsMarginY = 2.0f;
 
+            protected string _debugInfo;
+            protected Float2 _debugInfoSize;
             protected ScriptType _type;
             internal bool _isValueEditing;
 
@@ -52,6 +54,21 @@ namespace FlaxEditor.Surface.Archetypes
                 return title;
             }
 
+            public virtual void UpdateDebug(Behavior behavior)
+            {
+                BehaviorTreeNode instance = null;
+                if (behavior)
+                {
+                    // Try to use instance from the currently debugged behavior
+                    // TODO: support nodes from nested trees
+                    instance = behavior.Tree.GetNodeInstance(ID);
+                }
+                var size = _debugInfoSize;
+                UpdateDebugInfo(instance, behavior);
+                if (size != _debugInfoSize)
+                    ResizeAuto();
+            }
+
             protected virtual void UpdateTitle()
             {
                 string title = null;
@@ -69,6 +86,21 @@ namespace FlaxEditor.Surface.Archetypes
                 Title = title;
             }
 
+            protected virtual void UpdateDebugInfo(BehaviorTreeNode instance = null, Behavior behavior = null)
+            {
+                _debugInfo = null;
+                _debugInfoSize = Float2.Zero;
+                if (!instance)
+                    instance = Instance;
+                if (instance)
+                {
+                    // Get debug description for the node based on the current settings
+                    _debugInfo = Behavior.GetNodeDebugInfo(instance, behavior);
+                    if (!string.IsNullOrEmpty(_debugInfo))
+                        _debugInfoSize = Style.Current.FontSmall.MeasureText(_debugInfo);
+                }
+            }
+
             public override void OnLoaded(SurfaceNodeActions action)
             {
                 base.OnLoaded(action);
@@ -97,6 +129,7 @@ namespace FlaxEditor.Surface.Archetypes
                     Instance = null;
                 }
 
+                UpdateDebugInfo();
                 UpdateTitle();
             }
 
@@ -129,6 +162,7 @@ namespace FlaxEditor.Surface.Archetypes
                     }
                 }
 
+                UpdateDebugInfo();
                 UpdateTitle();
             }
 
@@ -139,10 +173,23 @@ namespace FlaxEditor.Surface.Archetypes
                 ResizeAuto();
             }
 
+            public override void Draw()
+            {
+                base.Draw();
+
+                // Debug Info
+                if (!string.IsNullOrEmpty(_debugInfo))
+                {
+                    var style = Style.Current;
+                    Render2D.DrawText(style.FontSmall, _debugInfo, new Rectangle(4, _headerRect.Bottom + 4, _debugInfoSize), style.Foreground);
+                }
+            }
+
             public override void OnDestroy()
             {
                 if (IsDisposing)
                     return;
+                _debugInfo = null;
                 _type = ScriptType.Null;
                 FlaxEngine.Object.Destroy(ref Instance);
 
@@ -258,6 +305,7 @@ namespace FlaxEditor.Surface.Archetypes
             {
                 get
                 {
+                    // Return decorator nodes attached to this node to be moved/copied/pasted as a one
                     SurfaceNode[] result = null;
                     var ids = Values.Length >= 3 ? Values[2] as byte[] : null;
                     if (ids != null)
@@ -425,6 +473,11 @@ namespace FlaxEditor.Surface.Archetypes
                 var titleLabelFont = Style.Current.FontLarge;
                 width = Mathf.Max(width, 100.0f);
                 width = Mathf.Max(width, titleLabelFont.MeasureText(Title).X + 30);
+                if (_debugInfoSize.X > 0)
+                {
+                    width = Mathf.Max(width, _debugInfoSize.X + 8.0f);
+                    height += _debugInfoSize.Y + 8.0f;
+                }
                 if (_input != null && _input.Visible)
                     height += ConnectionAreaHeight;
                 if (_output != null && _output.Visible)
@@ -463,9 +516,12 @@ namespace FlaxEditor.Surface.Archetypes
                 const float closeButtonSize = FlaxEditor.Surface.Constants.NodeCloseButtonSize;
                 _headerRect = new Rectangle(0, bounds.Y - Y, bounds.Width, headerSize);
                 _closeButtonRect = new Rectangle(bounds.Width - closeButtonSize - closeButtonMargin, _headerRect.Y + closeButtonMargin, closeButtonSize, closeButtonSize);
-                _footerRect = new Rectangle(0, _headerRect.Bottom, bounds.Width, footerSize);
+                _footerRect = new Rectangle(0, bounds.Height - footerSize, bounds.Width, footerSize);
                 if (_output != null && _output.Visible)
+                {
+                    _footerRect.Y -= ConnectionAreaHeight;
                     _output.Bounds = new Rectangle(ConnectionAreaMargin, bounds.Height - ConnectionAreaHeight, bounds.Width - ConnectionAreaMargin * 2, ConnectionAreaHeight);
+                }
             }
 
             protected override void OnLocationChanged()
@@ -589,7 +645,12 @@ namespace FlaxEditor.Surface.Archetypes
 
             protected override Float2 CalculateNodeSize(float width, float height)
             {
-                return new Float2(width + FlaxEditor.Surface.Constants.NodeCloseButtonSize + 2 * DecoratorsMarginX, height + FlaxEditor.Surface.Constants.NodeHeaderSize);
+                if (_debugInfoSize.X > 0)
+                {
+                    width = Mathf.Max(width, _debugInfoSize.X + 8.0f);
+                    height += _debugInfoSize.Y + 8.0f;
+                }
+                return new Float2(width + FlaxEditor.Surface.Constants.NodeCloseButtonSize * 2 + DecoratorsMarginX * 2, height + FlaxEditor.Surface.Constants.NodeHeaderSize);
             }
 
             protected override void UpdateRectangles()
@@ -603,15 +664,22 @@ namespace FlaxEditor.Surface.Archetypes
 
             protected override void UpdateTitle()
             {
-                var title = Title;
-
-                base.UpdateTitle();
-
                 // Update parent node on title change
+                var title = Title;
+                base.UpdateTitle();
                 if (title != Title)
                     Node?.ResizeAuto();
             }
 
+            protected override void UpdateDebugInfo(BehaviorTreeNode instance, Behavior behavior)
+            {
+                // Update parent node on debug text change
+                var debugInfoSize = _debugInfoSize;
+                base.UpdateDebugInfo(instance, behavior);
+                if (debugInfoSize != _debugInfoSize)
+                    Node?.ResizeAuto();
+            }
+
             public override void OnLoaded(SurfaceNodeActions action)
             {
                 // Add drag button to reorder decorator

Source/Editor/Windows/Assets/BehaviorTreeWindow.cs

@@ -449,6 +449,18 @@ namespace FlaxEditor.Windows.Assets
             UpdateKnowledge();
         }
 
+        private void UpdateDebugInfos(bool playMode)
+        {
+            var behavior = playMode ? (Behavior)_behaviorPicker.Value : null;
+            if (!behavior)
+                behavior = null;
+            foreach (var e in _surface.Nodes)
+            {
+                if (e is Surface.Archetypes.BehaviorTree.NodeBase node)
+                    node.UpdateDebug(behavior);
+            }
+        }
+
         /// <inheritdoc />
         public override void OnPlayBegin()
         {
@@ -461,6 +473,7 @@ namespace FlaxEditor.Windows.Assets
         public override void OnPlayEnd()
         {
             SetCanEdit(true);
+            UpdateDebugInfos(false);
 
             base.OnPlayEnd();
         }
@@ -520,6 +533,12 @@ namespace FlaxEditor.Windows.Assets
             // Update behavior debugging
             SetCanDebug(Editor.IsPlayMode && _behaviorPicker.Value);
 
+            // Update debug info texts on all nodes
+            if (Editor.IsPlayMode)
+            {
+                UpdateDebugInfos(true);
+            }
+
             base.Update(deltaTime);
         }
 

Source/Engine/AI/Behavior.cpp

@@ -166,3 +166,25 @@ void Behavior::OnDisable()
 {
     BehaviorServiceInstance.UpdateList.Remove(this);
 }
+
+#if USE_EDITOR
+
+String Behavior::GetNodeDebugInfo(BehaviorTreeNode* node, Behavior* behavior)
+{
+    if (!node)
+        return String::Empty;
+    BehaviorUpdateContext context;
+    Platform::MemoryClear(&context, sizeof(context));
+    if (behavior && behavior->_knowledge.RelevantNodes.Get(node->_executionIndex))
+    {
+        // Pass behavior and knowledge data only for relevant nodes to properly access it
+        context.Behavior = behavior;
+        context.Knowledge = &behavior->_knowledge;
+        context.Memory = behavior->_knowledge.Memory;
+        context.RelevantNodes = &behavior->_knowledge.RelevantNodes;
+        context.Time = behavior->_totalTime;
+    }
+    return node->GetDebugInfo(context);
+}
+
+#endif

Source/Engine/AI/Behavior.h

@@ -27,7 +27,6 @@ private:
     float _accumulatedTime = 0.0f;
     float _totalTime = 0.0f;
     BehaviorUpdateResult _result = BehaviorUpdateResult::Success;
-    void* _memory = nullptr;
 
     void UpdateAsync();
 
@@ -91,4 +90,10 @@ public:
     // [Script]
     void OnEnable() override;
     void OnDisable() override;
+
+private:
+#if USE_EDITOR
+    // Editor-only utility to debug nodes state.
+    API_FUNCTION(Internal) static String GetNodeDebugInfo(BehaviorTreeNode* node, Behavior* behavior);
+#endif
 };

Source/Engine/AI/BehaviorKnowledge.cpp

@@ -119,12 +119,12 @@ bool AccessBehaviorKnowledge(BehaviorKnowledge* knowledge, const StringAnsiView&
     return false;
 }
 
-bool BehaviorKnowledgeSelectorAny::Set(BehaviorKnowledge* knowledge, const Variant& value)
+bool BehaviorKnowledgeSelectorAny::Set(BehaviorKnowledge* knowledge, const Variant& value) const
 {
     return knowledge && knowledge->Set(Path, value);
 }
 
-Variant BehaviorKnowledgeSelectorAny::Get(BehaviorKnowledge* knowledge)
+Variant BehaviorKnowledgeSelectorAny::Get(const BehaviorKnowledge* knowledge) const
 {
     Variant value;
     if (knowledge)
@@ -132,7 +132,7 @@ Variant BehaviorKnowledgeSelectorAny::Get(BehaviorKnowledge* knowledge)
     return value;
 }
 
-bool BehaviorKnowledgeSelectorAny::TryGet(BehaviorKnowledge* knowledge, Variant& value)
+bool BehaviorKnowledgeSelectorAny::TryGet(const BehaviorKnowledge* knowledge, Variant& value) const
 {
     return knowledge && knowledge->Get(Path, value);
 }
@@ -182,9 +182,9 @@ void BehaviorKnowledge::FreeMemory()
     Tree = nullptr;
 }
 
-bool BehaviorKnowledge::Get(const StringAnsiView& path, Variant& value)
+bool BehaviorKnowledge::Get(const StringAnsiView& path, Variant& value) const
 {
-    return AccessBehaviorKnowledge(this, path, value, false);
+    return AccessBehaviorKnowledge(const_cast<BehaviorKnowledge*>(this), path, value, false);
 }
 
 bool BehaviorKnowledge::Set(const StringAnsiView& path, const Variant& value)

Source/Engine/AI/BehaviorKnowledge.h

@@ -67,7 +67,7 @@ public:
     /// <param name="path">Selector path.</param>
     /// <param name="value">Result value (valid only when returned true).</param>
     /// <returns>True if got value, otherwise false.</returns>
-    API_FUNCTION() bool Get(const StringAnsiView& path, API_PARAM(Out) Variant& value);
+    API_FUNCTION() bool Get(const StringAnsiView& path, API_PARAM(Out) Variant& value) const;
 
     /// <summary>
     /// Sets the knowledge item value via selector path.

Source/Engine/AI/BehaviorKnowledgeSelector.h

@@ -21,13 +21,13 @@ API_STRUCT(NoDefault, MarshalAs=StringAnsi) struct FLAXENGINE_API BehaviorKnowle
     API_FIELD() StringAnsi Path;
 
     // Sets the selected knowledge value (as Variant).
-    bool Set(BehaviorKnowledge* knowledge, const Variant& value);
+    bool Set(BehaviorKnowledge* knowledge, const Variant& value) const;
 
     // Gets the selected knowledge value (as Variant).
-    Variant Get(BehaviorKnowledge* knowledge);
+    Variant Get(const BehaviorKnowledge* knowledge) const;
 
     // Tries to get the selected knowledge value (as Variant). Returns true if got value, otherwise false.
-    bool TryGet(BehaviorKnowledge* knowledge, Variant& value);
+    bool TryGet(const BehaviorKnowledge* knowledge, Variant& value) const;
 
     FORCE_INLINE bool operator==(const BehaviorKnowledgeSelectorAny& other) const
     {
@@ -63,19 +63,19 @@ API_STRUCT(InBuild, Template, MarshalAs=StringAnsi) struct FLAXENGINE_API Behavi
     using BehaviorKnowledgeSelectorAny::TryGet;
 
     // Sets the selected knowledge value (typed).
-    FORCE_INLINE void Set(BehaviorKnowledge* knowledge, const T& value)
+    FORCE_INLINE void Set(BehaviorKnowledge* knowledge, const T& value) const
     {
         BehaviorKnowledgeSelectorAny::Set(knowledge, Variant(value));
     }
 
     // Gets the selected knowledge value (typed).
-    FORCE_INLINE T Get(BehaviorKnowledge* knowledge)
+    FORCE_INLINE T Get(const BehaviorKnowledge* knowledge) const
     {
         return TVariantValueCast<T>::Cast(BehaviorKnowledgeSelectorAny::Get(knowledge));
     }
 
     // Tries to get the selected knowledge value (typed). Returns true if got value, otherwise false.
-    FORCE_INLINE bool TryGet(BehaviorKnowledge* knowledge, T& value)
+    FORCE_INLINE bool TryGet(const BehaviorKnowledge* knowledge, T& value)
     {
         Variant variant;
         if (BehaviorKnowledgeSelectorAny::TryGet(knowledge, variant))

Source/Engine/AI/BehaviorTree.cpp

@@ -17,6 +17,8 @@
 
 REGISTER_BINARY_ASSET(BehaviorTree, "FlaxEngine.BehaviorTree", false);
 
+#define IS_BT_NODE(n) (n.GroupID == 19 && (n.TypeID == 1 || n.TypeID == 2 || n.TypeID == 3))
+
 bool SortBehaviorTreeChildren(GraphBox* const& a, GraphBox* const& b)
 {
     // Sort by node X coordinate on surface
@@ -45,7 +47,8 @@ void BehaviorTreeGraph::Clear()
 
 bool BehaviorTreeGraph::onNodeLoaded(Node* n)
 {
-    if (n->GroupID == 19 && (n->TypeID == 1 || n->TypeID == 2 || n->TypeID == 3))
+    const Node& node = *n;
+    if (IS_BT_NODE(node))
     {
         // Create node instance object
         ScriptingTypeHandle type = Scripting::FindScriptingType((StringAnsiView)n->Values[0]);
@@ -151,6 +154,16 @@ BehaviorTree::BehaviorTree(const SpawnParams& params, const AssetInfo* info)
 {
 }
 
+BehaviorTreeNode* BehaviorTree::GetNodeInstance(uint32 id)
+{
+    for (const auto& node : Graph.Nodes)
+    {
+        if (node.ID == id && node.Instance && IS_BT_NODE(node))
+            return node.Instance;
+    }
+    return nullptr;
+}
+
 BytesContainer BehaviorTree::LoadSurface()
 {
     if (WaitForLoaded())

Source/Engine/AI/BehaviorTree.h

@@ -66,6 +66,13 @@ public:
     /// </summary>
     BehaviorTreeGraph Graph;
 
+    /// <summary>
+    /// Gets a specific node instance object from Behavior Tree.
+    /// </summary>
+    /// <param name="id">The unique node identifier (Visject surface).</param>
+    /// <returns>The node instance or null if cannot get it.</returns>
+    API_FUNCTION() BehaviorTreeNode* GetNodeInstance(uint32 id);
+
     /// <summary>
     /// Tries to load surface graph from the asset.
     /// </summary>

Source/Engine/AI/BehaviorTreeNode.h

@@ -12,6 +12,7 @@
 API_CLASS(Abstract) class FLAXENGINE_API BehaviorTreeNode : public SerializableScriptingObject
 {
     DECLARE_SCRIPTING_TYPE_WITH_CONSTRUCTOR_IMPL(BehaviorTreeNode, SerializableScriptingObject);
+    friend class Behavior;
     friend class BehaviorTreeGraph;
     friend class BehaviorKnowledge;
     friend class BehaviorTreeSubTreeNode;
@@ -76,6 +77,18 @@ public:
         return BehaviorUpdateResult::Success;
     }
 
+#if USE_EDITOR
+    /// <summary>
+    /// Gets the node debug state text (multiline). Used in Editor-only to display nodes state. Can be called without valid Behavior/Knowledge/Memory to display default debug info (eg. node properties).
+    /// </summary>
+    /// <param name="context">Behavior context data.</param>
+    /// <returns>Debug info text (multiline).</returns>
+    API_FUNCTION() virtual String GetDebugInfo(const BehaviorUpdateContext& context) const
+    {
+        return String::Empty;
+    }
+#endif
+
     // Helper utility to update node with state creation/cleanup depending on node relevancy.
     BehaviorUpdateResult InvokeUpdate(const BehaviorUpdateContext& context);
     // Helper utility to make node relevant and init it state.

Source/Engine/AI/BehaviorTreeNodes.cpp

@@ -6,6 +6,7 @@
 #include "Engine/Core/Random.h"
 #include "Engine/Scripting/Scripting.h"
 #if USE_CSHARP
+#include "Engine/Core/Utilities.h"
 #include "Engine/Scripting/ManagedCLR/MClass.h"
 #endif
 #include "Engine/Engine/Engine.h"
@@ -264,6 +265,28 @@ BehaviorUpdateResult BehaviorTreeDelayNode::Update(const BehaviorUpdateContext&
     return state->TimeLeft <= 0.0f ? BehaviorUpdateResult::Success : BehaviorUpdateResult::Running;
 }
 
+#if USE_EDITOR
+
+String BehaviorTreeDelayNode::GetDebugInfo(const BehaviorUpdateContext& context) const
+{
+    if (context.Memory)
+    {
+        const auto state = GetState<State>(context.Memory);
+        return String::Format(TEXT("Time Left: {}s"), Utilities::RoundTo2DecimalPlaces(state->TimeLeft));
+    }
+
+    String delay;
+    if (WaitTimeSelector.Path.HasChars())
+        delay = String(WaitTimeSelector.Path);
+    else
+        delay = StringUtils::ToString(WaitTime);
+    if (RandomDeviation > 0.0f)
+        delay += String::Format(TEXT("+/-{}"), RandomDeviation);
+    return String::Format(TEXT("Delay: {}s"), delay);
+}
+
+#endif
+
 int32 BehaviorTreeSubTreeNode::GetStateSize() const
 {
     return sizeof(State);
@@ -481,6 +504,35 @@ BehaviorUpdateResult BehaviorTreeMoveToNode::Update(const BehaviorUpdateContext&
     return state->Result;
 }
 
+#if USE_EDITOR
+
+String BehaviorTreeMoveToNode::GetDebugInfo(const BehaviorUpdateContext& context) const
+{
+    if (context.Memory)
+    {
+        const auto state = GetState<State>(context.Memory);
+        if (state->Agent)
+        {
+            const String agent = state->Agent->GetNamePath();
+            String goal;
+            const Actor* target = Target.Get(context.Knowledge);
+            if (target)
+                goal = target->GetNamePath();
+            else
+                goal = state->GoalLocation.ToString();
+            const Vector3 agentLocation = state->Agent->GetPosition();
+            const Vector3 agentLocationOnPath = agentLocation + state->AgentOffset;
+            float distanceLeft = state->Path.Count() > state->TargetPathIndex ? Vector3::Distance(state->Path[state->TargetPathIndex], agentLocationOnPath) : 0;
+            for (int32 i = state->TargetPathIndex; i < state->Path.Count(); i++)
+                distanceLeft += Vector3::Distance(state->Path[i - 1], state->Path[i]);
+            return String::Format(TEXT("Agent: '{}'\nGoal: '{}'\nDistance: {}"), agent, goal, (int32)distanceLeft);
+        }
+    }
+    return String::Empty;
+}
+
+#endif
+
 void BehaviorTreeMoveToNode::State::OnUpdate()
 {
     if (Result != BehaviorUpdateResult::Running)

Source/Engine/AI/BehaviorTreeNodes.h

@@ -122,6 +122,9 @@ public:
     int32 GetStateSize() const override;
     void InitState(const BehaviorUpdateContext& context) override;
     BehaviorUpdateResult Update(const BehaviorUpdateContext& context) override;
+#if USE_EDITOR
+    String GetDebugInfo(const BehaviorUpdateContext& context) const override;
+#endif
 
 private:
     struct State
@@ -233,6 +236,9 @@ public:
     void InitState(const BehaviorUpdateContext& context) override;
     void ReleaseState(const BehaviorUpdateContext& context) override;
     BehaviorUpdateResult Update(const BehaviorUpdateContext& context) override;
+#if USE_EDITOR
+    String GetDebugInfo(const BehaviorUpdateContext& context) const override;
+#endif
 
 protected:
     struct State