Started working on evaluating embedded blend trees.

src/AnimGraph/AnimGraphBlendTree.cc

@@ -73,7 +73,7 @@ void AnimGraphBlendTree::MarkActiveInputs() {
     }
   }
 
-  for (size_t i = m_eval_ordered_nodes.size() - 1; i > 0; i--) {
+  for (size_t i = m_eval_ordered_nodes.size() - 1; i >= 0; i--) {
     AnimNode* node = m_eval_ordered_nodes[i];
     if (checkIsNodeActive(node)) {
       node->MarkActiveInputs();

src/AnimGraph/AnimGraphBlendTree.h

@@ -29,10 +29,10 @@ struct AnimGraphBlendTree : public AnimNode {
 
   AnimDataAllocator m_anim_data_allocator;
 
-  ~AnimGraphBlendTree() { dealloc(); }
+  ~AnimGraphBlendTree() override { dealloc(); }
 
   // AnimNode overrides
-  bool Init(AnimGraphContext& context);
+  bool Init(AnimGraphContext& context) override;
   void MarkActiveInputs() override;
   void CalcSyncTrack() override;
   void UpdateTime(float time_last, float time_now) override;

src/AnimGraph/AnimGraphNodes.cc

@@ -3,6 +3,7 @@
 //
 
 #include "AnimGraphNodes.h"
+#include "AnimGraphBlendTree.h"
 
 #include "ozz/base/log.h"
 #include "ozz/animation/runtime/blending_job.h"
@@ -10,6 +11,38 @@
 #include "ozz/base/io/archive.h"
 #include "ozz/base/io/stream.h"
 
+AnimNode* AnimNodeFactory(const std::string& name) {
+  AnimNode* result;
+  if (name == "Blend2") {
+    result = new Blend2Node;
+  } else if (name == "SpeedScale") {
+    result = new SpeedScaleNode;
+  } else if (name == "AnimSampler") {
+    result = new AnimSamplerNode;
+  } else if (name == "LockTranslationNode") {
+    result = new LockTranslationNode;
+  } else if (name == "BlendTree") {
+    result = new AnimGraphBlendTree;
+  } else if (name == "BlendTreeSockets") {
+    result = new BlendTreeNode;
+  } else if (name == "MathAddNode") {
+    result = new MathAddNode;
+  } else if (name == "MathFloatToVec3Node") {
+    result = new MathFloatToVec3Node;
+  } else if (name == "ConstScalarNode") {
+    result = new ConstScalarNode;
+  }
+
+  if (result != nullptr) {
+    result->m_node_type_name = name;
+    return result;
+  }
+
+  std::cerr << "Invalid node type: " << name << std::endl;
+  return nullptr;
+}
+
+
 void Blend2Node::Evaluate(AnimGraphContext& context) {
   assert (i_input0 != nullptr);
   assert (i_input1 != nullptr);

src/AnimGraph/AnimGraphNodes.h

@@ -250,36 +250,7 @@ struct NodeDescriptor<MathFloatToVec3Node> : public NodeDescriptorBase {
 };
 
 
-static inline AnimNode* AnimNodeFactory(const std::string& name) {
-  AnimNode* result;
-  if (name == "Blend2") {
-    result = new Blend2Node;
-  } else if (name == "SpeedScale") {
-    result = new SpeedScaleNode;
-  } else if (name == "AnimSampler") {
-    result = new AnimSamplerNode;
-  } else if (name == "LockTranslationNode") {
-    result = new LockTranslationNode;
-  } else if (name == "BlendTree") {
-    result = new BlendTreeNode;
-  } else if (name == "BlendTreeSockets") {
-    result = new BlendTreeNode;
-  } else if (name == "MathAddNode") {
-    result = new MathAddNode;
-  } else if (name == "MathFloatToVec3Node") {
-    result = new MathFloatToVec3Node;
-  } else if (name == "ConstScalarNode") {
-    result = new ConstScalarNode;
-  }
-
-  if (result != nullptr) {
-    result->m_node_type_name = name;
-    return result;
-  }
-
-  std::cerr << "Invalid node type: " << name << std::endl;
-  return nullptr;
-}
+AnimNode* AnimNodeFactory(const std::string& name);
 
 static inline NodeDescriptorBase* AnimNodeDescriptorFactory(
     const std::string& node_type_name,

src/AnimGraph/AnimGraphResource.cc

@@ -483,6 +483,18 @@ void AnimGraphResource::CreateBlendTreeRuntimeNodeInstances(
     AnimGraphBlendTree& result) const {
   for (auto node_resource : m_blend_tree_resource.m_nodes) {
     AnimNode* node = AnimNodeFactory(node_resource->m_node_type_name);
+
+    if (node_resource->m_node_type_name == "BlendTree") {
+      AnimGraphResource* embedded_blend_tree_resource = dynamic_cast<AnimGraphResource*>(node_resource);
+      assert(embedded_blend_tree_resource != nullptr);
+      AnimGraphBlendTree* embedded_blend_tree = dynamic_cast<AnimGraphBlendTree*>(node);
+      assert(embedded_blend_tree != nullptr);
+
+      embedded_blend_tree_resource->CreateBlendTreeInstance(*embedded_blend_tree);
+      embedded_blend_tree_resource->m_socket_accessor->m_inputs = embedded_blend_tree->m_node_descriptor->m_outputs;
+      embedded_blend_tree_resource->m_socket_accessor->m_outputs = embedded_blend_tree->m_node_descriptor->m_inputs;
+    }
+
     node->m_name = node_resource->m_name;
     node->m_node_type_name = node_resource->m_node_type_name;
     result.m_nodes.push_back(node);
@@ -497,6 +509,7 @@ void AnimGraphResource::PrepareBlendTreeIOData(
     AnimGraphBlendTree& instance) const {
   instance.m_node_descriptor =
       AnimNodeDescriptorFactory("BlendTree", instance.m_nodes[0]);
+
   instance.m_node_descriptor->m_outputs =
       m_blend_tree_resource.m_nodes[1]->m_socket_accessor->m_outputs;
   instance.m_node_descriptor->m_inputs =
@@ -566,9 +579,16 @@ void AnimGraphResource::PrepareBlendTreeIOData(
       m_blend_tree_resource.m_nodes.size(),
       nullptr);
   for (int i = 0; i < m_blend_tree_resource.m_nodes.size(); i++) {
-    instance_node_descriptors[i] = AnimNodeDescriptorFactory(
-        m_blend_tree_resource.m_nodes[i]->m_node_type_name,
-        instance.m_nodes[i]);
+      instance_node_descriptors[i] = AnimNodeDescriptorFactory(
+          m_blend_tree_resource.m_nodes[i]->m_node_type_name,
+          instance.m_nodes[i]);
+
+    if (i > 1 && m_blend_tree_resource.m_nodes[i]->m_node_type_name == "BlendTree") {
+      instance_node_descriptors[i]->m_inputs =
+          m_blend_tree_resource.m_nodes[i]->m_socket_accessor->m_inputs;
+      instance_node_descriptors[i]->m_outputs =
+          m_blend_tree_resource.m_nodes[i]->m_socket_accessor->m_outputs;
+    }
   }
 
   instance_node_descriptors[0]->m_inputs = instance.m_node_descriptor->m_inputs;

src/AnimGraph/AnimGraphResource.h

@@ -116,7 +116,6 @@ struct StateMachineResource {
 
 struct AnimGraphResource: AnimNodeResource {
   std::string m_graph_type_name;
-  std::string m_name;
 
   BlendTreeResource m_blend_tree_resource;
   StateMachineResource m_state_machine_resource;

tests/AnimGraphResourceTests.cc

@@ -181,6 +181,7 @@ class EmbeddedBlendTreeGraphResource {
         parent_blend_tree_resource->m_nodes.back());
     embedded_graph->m_name = "EmbeddedBlendTree";
     embedded_graph->m_node_type_name = "BlendTree";
+    embedded_graph->m_graph_type_name = "BlendTree";
     embedded_blend_tree_resource = &embedded_graph->m_blend_tree_resource;
 
     // Embedded: outputs
@@ -202,6 +203,7 @@ class EmbeddedBlendTreeGraphResource {
         AnimNodeResourceFactory("SpeedScale"));
     AnimNodeResource* embedded_speed_scale_resource =
         embedded_blend_tree_resource->m_nodes.back();
+    embedded_speed_scale_resource->m_socket_accessor->SetInputValue("SpeedScale", 0.1f);
 
     // Embedded: setup connections
     embedded_blend_tree_resource->ConnectSockets(
@@ -1022,3 +1024,37 @@ TEST_CASE_METHOD(
         == embedded_connection_loaded.target_socket_name);
   }
 }
+
+TEST_CASE_METHOD(
+    EmbeddedBlendTreeGraphResource,
+    "EmbeddedBlendTreeGraphResource instantiation",
+    "[EmbeddedBlendTreeGraphResource]") {
+  AnimGraphBlendTree blend_tree;
+
+  parent_graph_resource.CreateBlendTreeInstance(blend_tree);
+  AnimGraphContext graph_context;
+
+  ozz::animation::Skeleton skeleton;
+  REQUIRE(load_skeleton(skeleton, "media/skeleton.ozz"));
+  graph_context.m_skeleton = &skeleton;
+
+  blend_tree.Init(graph_context);
+  // Marking of active inputs is not properly working as we do not properly
+  // populate AnimNode::m_inputs.
+  //
+  // Here comes an iffy problem: How to mark nodes in a parent blend tree
+  //   as active?
+  //
+  // - Simplest would be if the AnimNodes don't distinguish between nodes within
+  //   the tree they are contained or in a possible parent (or nested) tree.
+  // - But then how to propagate active connections across multiple layers?
+  // - Therefore probably better to have a blend tree store which sockets are
+  //   active and use that within the graph.
+  // - But then: AnimGraphConnection already stores raw AnimNode pointers of the
+  //   connected nodes. Still... populating them accross layers could be messy.
+  blend_tree.MarkActiveInputs();
+  blend_tree.UpdateTime(0.f, 0.1f);
+  blend_tree.Evaluate(graph_context);
+
+  graph_context.freeAnimations();
+}