Graph editor allows instantiation of different node types.

src/AnimGraphEditor.cc

@@ -4,16 +4,14 @@
 
 #include "AnimGraphEditor.h"
 
-#include "imnodes.h"
-
 #include "AnimGraphResource.h"
+#include "imnodes.h"
 
 static AnimGraphResource gGraphResource;
 
 constexpr int NodeInputAttributeFlag = 2 << 16;
 constexpr int NodeOutputAttributeFlag = 2 << 17;
 
-
 void AnimGraphEditorUpdate() {
   ImGui::BeginMenuBar();
   if (ImGui::Button("Save")) {
@@ -22,9 +20,11 @@ void AnimGraphEditorUpdate() {
   if (ImGui::Button("Load")) {
     gGraphResource.loadFromFile("editor_graph.json");
 
-    for (size_t i = 0, n = gGraphResource.m_nodes.size(); i < n; i++) {
+    for (size_t i = 1, n = gGraphResource.m_nodes.size(); i < n; i++) {
       const AnimNodeResource& node_resource = gGraphResource.m_nodes[i];
-      ImNodes::SetNodeGridSpacePos(i, ImVec2(node_resource.m_position[0], node_resource.m_position[1]));
+      ImNodes::SetNodeGridSpacePos(
+          i,
+          ImVec2(node_resource.m_position[0], node_resource.m_position[1]));
     }
   }
   if (ImGui::Button("Clear")) {
@@ -32,7 +32,10 @@ void AnimGraphEditorUpdate() {
   }
   char graph_name_buffer[256];
   memset(graph_name_buffer, 0, sizeof(graph_name_buffer));
-  strncpy (graph_name_buffer, gGraphResource.m_name.c_str(), sizeof(graph_name_buffer));
+  strncpy(
+      graph_name_buffer,
+      gGraphResource.m_name.c_str(),
+      sizeof(graph_name_buffer));
   if (ImGui::InputText("Name", graph_name_buffer, sizeof(graph_name_buffer))) {
     gGraphResource.m_name = graph_name_buffer;
   }
@@ -41,15 +44,48 @@ void AnimGraphEditorUpdate() {
 
   ImNodes::BeginNodeEditor();
 
-  if (ImGui::IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows) && ImNodes::IsEditorHovered()
-      && ImGui::IsMouseReleased(ImGuiMouseButton_Right)) {
-    AnimNodeResource node_resource = AnimNodeResourceFactory("Blend2");
+  // Popup menu
+  {
+    const bool open_popup =
+        ImGui::IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows)
+        && ImNodes::IsEditorHovered()
+        && ImGui::IsMouseReleased(ImGuiMouseButton_Right);
+
+    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(8.f, 8.f));
+    if (!ImGui::IsAnyItemHovered() && open_popup) {
+      ImGui::OpenPopup("add node");
+    }
+
+    if (ImGui::BeginPopup("add node")) {
+      const ImVec2 click_pos = ImGui::GetMousePosOnOpeningCurrentPopup();
+      std::string node_type_name = "";
+      if (ImGui::MenuItem("AnimSampler")) {
+        node_type_name = "AnimSampler";
+      }
+
+      if (ImGui::MenuItem("Blend2")) {
+        node_type_name = "Blend2";
+      }
+
+      if (ImGui::MenuItem("SpeedScale")) {
+        node_type_name = "SpeedScale";
+      }
+
+      if (node_type_name != "") {
+        AnimNodeResource node_resource =
+            AnimNodeResourceFactory(node_type_name);
         size_t node_id = gGraphResource.m_nodes.size();
         ImNodes::SetNodeScreenSpacePos(node_id, ImGui::GetMousePos());
         gGraphResource.m_nodes.push_back(node_resource);
       }
 
-  for (size_t i = 0, n = gGraphResource.m_nodes.size(); i < n; i++) {
+      ImGui::EndPopup();
+    }
+
+    ImGui::PopStyleVar(ImGuiStyleVar_WindowPadding);
+  }
+
+  for (size_t i = 1, n = gGraphResource.m_nodes.size(); i < n; i++) {
     AnimNodeResource& node_resource = gGraphResource.m_nodes[i];
 
     ImNodes::BeginNode(i);
@@ -60,7 +96,8 @@ void AnimGraphEditorUpdate() {
     ImNodes::EndNodeTitleBar();
 
     // Inputs
-    const std::vector<Socket>& node_inputs =node_resource.m_socket_accessor->m_inputs;
+    const std::vector<Socket>& node_inputs =
+        node_resource.m_socket_accessor->m_inputs;
     for (size_t j = 0, ni = node_inputs.size(); j < ni; j++) {
       const Socket& socket = node_inputs[j];
       ImNodes::BeginInputAttribute(GenerateInputAttributeId(i, j));
@@ -69,7 +106,8 @@ void AnimGraphEditorUpdate() {
     }
 
     // Outputs
-    const std::vector<Socket>& node_outputs =node_resource.m_socket_accessor->m_outputs;
+    const std::vector<Socket>& node_outputs =
+        node_resource.m_socket_accessor->m_outputs;
     for (size_t j = 0, ni = node_outputs.size(); j < ni; j++) {
       const Socket& socket = node_outputs[j];
       ImNodes::BeginOutputAttribute(GenerateOutputAttributeId(i, j));
@@ -87,8 +125,12 @@ void AnimGraphEditorUpdate() {
   for (size_t i = 0, n = gGraphResource.m_connections.size(); i < n; i++) {
     const AnimGraphConnection& connection = gGraphResource.m_connections[i];
     int start_attr, end_attr;
-    start_attr = GenerateOutputAttributeId(connection.m_source_node_index, connection.m_source_socket_index);
-    end_attr = GenerateInputAttributeId(connection.m_target_node_index, connection.m_target_socket_index);
+    start_attr = GenerateOutputAttributeId(
+        connection.m_source_node_index,
+        connection.m_source_socket_index);
+    end_attr = GenerateInputAttributeId(
+        connection.m_target_node_index,
+        connection.m_target_socket_index);
     ImNodes::Link(i, start_attr, end_attr);
   }
 
@@ -98,14 +140,18 @@ void AnimGraphEditorUpdate() {
   if (ImNodes::IsLinkCreated(&start_attr, &end_attr)) {
     int node_start_id;
     int node_start_output_index;
-    SplitOutputAttributeId(start_attr, &node_start_id, &node_start_output_index);
+    SplitOutputAttributeId(
+        start_attr,
+        &node_start_id,
+        &node_start_output_index);
 
     int node_end_id;
     int node_end_input_index;
     SplitInputAttributeId(end_attr, &node_end_id, &node_end_input_index);
 
-    std::cout << "Link created: " << node_start_id << ", " << node_start_output_index << " -> "
-              << node_end_id << ", " << node_end_input_index << std::endl;
+    std::cout << "Link created: " << node_start_id << ", "
+              << node_start_output_index << " -> " << node_end_id << ", "
+              << node_end_input_index << std::endl;
 
     AnimGraphConnection connection;
     connection.m_source_node_index = node_start_id;

src/AnimGraphResource.cc

@@ -88,6 +88,9 @@ AnimGraphConnection sAnimGraphConnectionFromJson(const json& json_node) {
 void AnimGraphResource::clear() {
   m_name = "";
   m_nodes.clear();
+
+  m_nodes.push_back(AnimNodeResourceFactory("BlendTree"));
+
   m_connections.clear();
 }
 
@@ -131,7 +134,8 @@ bool AnimGraphResource::loadFromFile (const char* filename) {
     std::cerr << "Invalid json object. Expected type 'AnimGraphResource' but got '" << json_data["type"] << "'." << std::endl;
   }
 
-  clear();
+  m_nodes.clear();
+  m_connections.clear();
 
   m_name = json_data["name"];
   for (size_t i = 0; i < json_data["nodes"].size(); i++) {

src/AnimGraphResource.h

@@ -5,6 +5,7 @@
 #ifndef ANIMTESTBED_ANIMGRAPHRESOURCE_H
 #define ANIMTESTBED_ANIMGRAPHRESOURCE_H
 
+#include <cstring>
 #include <iostream>
 #include <map>
 #include <string>
@@ -54,22 +55,13 @@ struct AnimNodeResource;
 
 struct Socket {
   std::string m_name;
-  SocketType m_type;
-  union Value {
-    bool* flag;
-    AnimData* anim_data;
-    float* real;
-    Vec3* vec3;
-    Quat* quat;
-    std::string* str;
-    bool** flag_ptr;
-    AnimData** anim_data_ptr;
-    float** real_ptr;
-    float** vec3_ptr;
-    float** quat_ptr;
-    std::string** str_ptr;
+  SocketType m_type = SocketType::SocketTypeUndefined;
+  union SocketValue {
+    void* ptr;
+    void** ptr_ptr;
   };
-  Value m_value;
+  SocketValue m_value = {nullptr};
+  size_t m_type_size = 0;
 };
 
 struct AnimNode;
@@ -96,7 +88,7 @@ struct AnimNode {
 };
 
 struct NodeSocketAccessorBase {
-  NodeSocketAccessorBase(AnimNode* node) {}
+  NodeSocketAccessorBase() {}
   virtual ~NodeSocketAccessorBase() {}
 
   Socket* FindSocket(std::vector<Socket>& sockets, const std::string& name) {
@@ -111,16 +103,43 @@ struct NodeSocketAccessorBase {
     return result;
   }
 
+  const Socket* FindSocket(
+      const std::vector<Socket>& sockets,
+      const std::string& name) const {
+    const Socket* result = nullptr;
+    for (size_t i = 0, n = sockets.size(); i < n; i++) {
+      if (sockets[i].m_name == name) {
+        result = &sockets[i];
+        break;
+      }
+    }
+
+    return result;
+  }
+
   SocketType GetSocketType(
-      const std::vector<Socket> sockets,
+      const std::vector<Socket>& sockets,
       const std::string& name) {
-    Socket* socket = FindSocket(m_properties, name);
+    const Socket* socket = FindSocket(sockets, name);
     if (socket == nullptr) {
       return SocketType::SocketTypeUndefined;
     }
     return socket->m_type;
   }
 
+  size_t GetSocketIndex(
+      const std::vector<Socket>& sockets,
+      const std::string& name) const {
+    for (size_t i = 0, n = sockets.size(); i < n; i++) {
+      std::cout << i << ", " << sockets[i].m_name << std::endl;
+      if (sockets[i].m_name == name) {
+        return i;
+      }
+    }
+
+    return -1;
+  }
+
   template <typename T>
   bool RegisterSocket(
       std::vector<Socket>& sockets,
@@ -135,137 +154,41 @@ struct NodeSocketAccessorBase {
     sockets.push_back(Socket());
     socket = &sockets[sockets.size() - 1];
     socket->m_name = name;
+    socket->m_type_size = sizeof(T);
 
     if constexpr (std::is_same<T, float>::value) {
-      socket->m_value.real = value_ptr;
       socket->m_type = SocketType::SocketTypeFloat;
     } else if constexpr (std::is_same<T, bool>::value) {
-      socket->m_value.flag = value_ptr;
       socket->m_type = SocketType::SocketTypeBool;
     } else if constexpr (std::is_same<T, Vec3>::value) {
-      socket->m_value.vec3 = value_ptr;
       socket->m_type = SocketType::SocketTypeVec3;
     } else if constexpr (std::is_same<T, Quat>::value) {
-      socket->m_value.quat = value_ptr;
       socket->m_type = SocketType::SocketTypeQuat;
     } else if constexpr (std::is_same<T, AnimData>::value) {
-      socket->m_value.anim_data = value_ptr;
       socket->m_type = SocketType::SocketTypeAnimation;
     } else if constexpr (std::is_same<T, std::string>::value) {
-      socket->m_value.str = value_ptr;
       socket->m_type = SocketType::SocketTypeString;
     } else if constexpr (std::is_same<T, float*>::value) {
-      socket->m_value.real_ptr = value_ptr;
       socket->m_type = SocketType::SocketTypeFloat;
     } else if constexpr (std::is_same<T, bool*>::value) {
-      socket->m_value.flag_ptr = value_ptr;
       socket->m_type = SocketType::SocketTypeBool;
     } else if constexpr (std::is_same<T, Vec3*>::value) {
-      socket->m_value.vec3_ptr = value_ptr;
       socket->m_type = SocketType::SocketTypeVec3;
     } else if constexpr (std::is_same<T, Quat*>::value) {
-      socket->m_value.quat_ptr = value_ptr;
       socket->m_type = SocketType::SocketTypeQuat;
     } else if constexpr (std::is_same<T, AnimData*>::value) {
-      socket->m_value.anim_data_ptr = value_ptr;
       socket->m_type = SocketType::SocketTypeAnimation;
     } else if constexpr (std::is_same<T, std::string*>::value) {
-      socket->m_value.str_ptr = value_ptr;
       socket->m_type = SocketType::SocketTypeString;
     } else {
       std::cerr << "Cannot register socket, invalid type." << std::endl;
       return false;
     }
 
+    socket->m_value.ptr = value_ptr;
     return true;
   }
 
-  template <typename T>
-  bool SetSocketValue(
-      std::vector<Socket>& sockets,
-      const std::string& name,
-      T value) {
-    Socket* socket = FindSocket(sockets, name);
-    if (socket == nullptr) {
-      return false;
-    }
-
-    if constexpr (std::is_same<T, float>::value) {
-      (*socket->m_value.real) = value;
-    } else if constexpr (std::is_same<T, bool>::value) {
-      (*socket->m_value.flag) = value;
-    } else if constexpr (std::is_same<T, Vec3>::value) {
-      (*socket->m_value.vec3) = value;
-    } else if constexpr (std::is_same<T, Quat>::value) {
-      (*socket->m_value.vec3) = value;
-    } else if constexpr (std::is_same<T, AnimData>::value) {
-      (*socket->m_value.vec3) = value;
-    } else if constexpr (std::is_same<T, std::string>::value) {
-      (*socket->m_value.str) = value;
-    } else {
-      std::cerr << "Invalid type!" << std::endl;
-      return false;
-    }
-
-    return true;
-  }
-
-  template <typename T>
-  bool SetSocketRef(
-      std::vector<Socket>& sockets,
-      const std::string& name,
-      T* value) {
-    Socket* socket = FindSocket(sockets, name);
-    if (socket == nullptr) {
-      return false;
-    } else if constexpr (std::is_same<T, float>::value) {
-      (*socket->m_value.real_ptr) = value;
-    } else if constexpr (std::is_same<T, bool>::value) {
-      (*socket->m_value.flag_ptr) = value;
-    } else if constexpr (std::is_same<T, Vec3>::value) {
-      (*socket->m_value.vec3_ptr) = value;
-    } else if constexpr (std::is_same<T, Quat>::value) {
-      (*socket->m_value.quat_ptr) = value;
-    } else if constexpr (std::is_same<T, AnimData>::value) {
-      (*socket->m_value.anim_data_ptr) = value;
-    } else if constexpr (std::is_same<T, std::string>::value) {
-      (*socket->m_value.str_ptr) = value;
-    } else {
-      std::cerr << "Invalid type!" << std::endl;
-      return false;
-    }
-
-    return true;
-  }
-
-  template <typename T>
-  T* GetSocketValue(
-      std::vector<Socket>& sockets,
-      const std::string& name,
-      T* default_value) {
-    Socket* socket = FindSocket(sockets, name);
-    if (socket == nullptr) {
-      return default_value;
-    }
-
-    if constexpr (std::is_same<T, float>::value) {
-      return socket->m_value.real;
-    } else if constexpr (std::is_same<T, Vec3>::value) {
-      return socket->m_value.vec3;
-    } else if constexpr (std::is_same<T, bool>::value) {
-      return socket->m_value.flag;
-    } else if constexpr (std::is_same<T, Quat>::value) {
-      return socket->m_value.vec3;
-    } else if constexpr (std::is_same<T, AnimData>::value) {
-      return socket->m_value.anim_data;
-    } else if constexpr (std::is_same<T, std::string>::value) {
-      return socket->m_value.str;
-    }
-
-    std::cerr << "Invalid type!" << std::endl;
-    return nullptr;
-  }
-
   template <typename T>
   bool RegisterProperty(const std::string& name, T* value) {
     return RegisterSocket(m_properties, name, value);
@@ -287,28 +210,32 @@ struct NodeSocketAccessorBase {
     return RegisterSocket(m_inputs, name, value);
   }
   template <typename T>
-  bool SetInput(const std::string& name, T value) {
-    return SetSocketValue(m_inputs, name, value);
-  }
-  template <typename T>
   T* GetInput(const std::string& name, T* value) {
     return GetSocketValue(m_inputs, name, value);
   }
+  Socket* FindInputSocket(const std::string& name) {
+    return FindSocket(m_inputs, name);
+  }
   SocketType GetInputType(const std::string& name) {
     return GetSocketType(m_inputs, name);
   }
+  size_t GetInputIndex(const std::string& name) {
+    return GetSocketIndex(m_inputs, name);
+  }
 
   template <typename T>
   bool RegisterOutput(const std::string& name, T** value) {
     return RegisterSocket(m_outputs, name, value);
   }
-  template <typename T>
-  bool SetOutputRef(const std::string& name, T* value) {
-    return SetSocketRef(m_outputs, name, value);
-  }
   SocketType GetOutputType(const std::string& name) {
     return GetSocketType(m_outputs, name);
   }
+  Socket* FindOutputSocket(const std::string& name) {
+    return FindSocket(m_outputs, name);
+  }
+  size_t GetOutputIndex(const std::string& name) {
+    return GetSocketIndex(m_outputs, name);
+  }
 
   std::vector<Socket> m_properties;
   std::vector<Socket> m_inputs;
@@ -327,6 +254,13 @@ struct NodeRegistry {
       AnimNode* node);
 };
 
+struct BlendTreeNode : public AnimNode {};
+
+template <>
+struct NodeSocketAccessor<BlendTreeNode> : public NodeSocketAccessorBase {
+  NodeSocketAccessor(AnimNode* node_) {}
+};
+
 struct Blend2Node : public AnimNode {
   AnimData m_input0;
   AnimData m_input1;
@@ -337,7 +271,7 @@ struct Blend2Node : public AnimNode {
 
 template <>
 struct NodeSocketAccessor<Blend2Node> : public NodeSocketAccessorBase {
-  NodeSocketAccessor(AnimNode* node_) : NodeSocketAccessorBase(node_) {
+  NodeSocketAccessor(AnimNode* node_) {
     Blend2Node* node = dynamic_cast<Blend2Node*>(node_);
     RegisterInput("Input0", &node->m_input0);
     RegisterInput("Input1", &node->m_input1);
@@ -357,7 +291,7 @@ struct SpeedScaleNode : public AnimNode {
 
 template <>
 struct NodeSocketAccessor<SpeedScaleNode> : public NodeSocketAccessorBase {
-  NodeSocketAccessor(AnimNode* node_) : NodeSocketAccessorBase(node_) {
+  NodeSocketAccessor(AnimNode* node_) {
     SpeedScaleNode* node = dynamic_cast<SpeedScaleNode*>(node_);
     RegisterInput("SpeedScale", &node->m_speed_scale);
     RegisterInput("Input", &node->m_input);
@@ -373,7 +307,7 @@ struct AnimSamplerNode : public AnimNode {
 
 template <>
 struct NodeSocketAccessor<AnimSamplerNode> : public NodeSocketAccessorBase {
-  NodeSocketAccessor(AnimNode* node_) : NodeSocketAccessorBase(node_) {
+  NodeSocketAccessor(AnimNode* node_) {
     AnimSamplerNode* node = dynamic_cast<AnimSamplerNode*>(node_);
     RegisterOutput("Output", &node->m_output);
 
@@ -392,21 +326,41 @@ struct AnimGraphResource {
   std::string m_name;
   std::vector<AnimNodeResource> m_nodes;
   std::vector<AnimGraphConnection> m_connections;
-  std::vector<Socket> m_inputs;
-  std::vector<Socket> m_outputs;
+
+  ~AnimGraphResource() {
+    for (size_t i = 0, n = m_nodes.size(); i < n; i++) {
+      delete m_nodes[i].m_anim_node;
+      delete m_nodes[i].m_socket_accessor;
+    }
+  }
+
+  AnimGraphResource() { clear(); }
 
   void clear();
   bool saveToFile(const char* filename) const;
   bool loadFromFile(const char* filename);
+
+  size_t addNode(AnimNodeResource node_resource) {
+    m_nodes.push_back(node_resource);
+    return m_nodes.size() - 1;
+  }
 };
 
 static inline AnimNode* AnimNodeFactory(const std::string& name) {
+  AnimNode* result;
   if (name == "Blend2") {
-    return new Blend2Node;
+    result = new Blend2Node;
   } else if (name == "SpeedScale") {
-    return new SpeedScaleNode;
+    result = new SpeedScaleNode;
   } else if (name == "AnimSampler") {
-    return new AnimSamplerNode;
+    result = new AnimSamplerNode;
+  } else if (name == "BlendTree") {
+    result = new BlendTreeNode;
+  }
+
+  if (result != nullptr) {
+    result->m_node_type_name = name;
+    return result;
   }
 
   std::cerr << "Invalid node type: " << name << std::endl;
@@ -422,6 +376,8 @@ static inline NodeSocketAccessorBase* AnimNodeAccessorFactory(
     return new NodeSocketAccessor<SpeedScaleNode>(node);
   } else if (node_type_name == "AnimSampler") {
     return new NodeSocketAccessor<AnimSamplerNode>(node);
+  } else if (node_type_name == "BlendTree") {
+    return new NodeSocketAccessor<BlendTreeNode>(node);
   } else {
     std::cerr << "Invalid node type name " << node_type_name << "."
               << std::endl;
@@ -446,6 +402,9 @@ struct AnimGraph {
   AnimData m_local_transforms;
   std::vector<AnimNode*> m_nodes;
   std::vector<std::vector<AnimNode*> > m_node_inputs;
+  NodeSocketAccessorBase* m_socket_accessor;
+  char* m_input_buffer = nullptr;
+  char* m_output_buffer = nullptr;
 
   AnimNode* getAnimNode(const char* name) {
     for (size_t i = 0; i < m_nodes.size(); i++) {
@@ -470,6 +429,8 @@ struct AnimGraph {
 
   static AnimGraph createFromResource(const AnimGraphResource& resource) {
     AnimGraph result;
+
+    // create nodes
     for (int i = 0; i < resource.m_nodes.size(); i++) {
       const AnimNodeResource& node_resource = resource.m_nodes[i];
       AnimNode* node = AnimNodeFactory(node_resource.m_type_name.c_str());
@@ -479,6 +440,27 @@ struct AnimGraph {
       result.m_node_inputs.push_back(std::vector<AnimNode*>());
     }
 
+    // Prepare graph inputs
+    const AnimNodeResource& graph_node = resource.m_nodes[0];
+    result.m_socket_accessor = AnimNodeAccessorFactory("BlendTree", result.m_nodes[0]);
+
+    int input_block_size = 0;
+    const std::vector<Socket>& graph_inputs =
+        graph_node.m_socket_accessor->m_inputs;
+    for (int i = 0; i < graph_inputs.size(); i++) {
+      input_block_size += graph_inputs[i].m_type_size;
+    }
+    result.m_input_buffer = new char[input_block_size];
+    memset(result.m_input_buffer, 0, input_block_size);
+    int input_block_offset = 0;
+    for (int i = 0; i < graph_inputs.size(); i++) {
+      if (graph_inputs[i].m_type == SocketType::SocketTypeAnimation) {
+        result.m_socket_accessor->RegisterInput<AnimData>(graph_inputs[i].m_name, static_cast<AnimData*>( (void*) &result.m_input_buffer[input_block_offset]));
+      }
+      input_block_offset += graph_inputs[i].m_type_size;
+    }
+
+    // connect the nodes
     for (int i = 0; i < resource.m_connections.size(); i++) {
       const AnimGraphConnection& connection = resource.m_connections[i];
       std::string source_node_type = "";
@@ -504,9 +486,13 @@ struct AnimGraph {
         target_node = result.m_nodes[connection.m_target_node_index];
         target_node_name = target_node->m_name;
         target_node_type = target_node->m_node_type_name;
+        if (connection.m_target_node_index == 0) {
+          target_node_accessor = result.m_socket_accessor;
+        } else {
           target_node_accessor =
               AnimNodeAccessorFactory(target_node_type, target_node);
         }
+      }
 
       assert(source_node != nullptr);
       assert(target_node != nullptr);
@@ -529,23 +515,26 @@ struct AnimGraph {
         continue;
       }
 
-      if (source_node_accessor->m_outputs[connection.m_source_socket_index].m_type
-          != target_node_accessor->m_inputs[connection.m_target_socket_index].m_type) {
+      if (source_node_accessor->m_outputs[connection.m_source_socket_index]
+              .m_type
+          != target_node_accessor->m_inputs[connection.m_target_socket_index]
+                 .m_type) {
         std::cerr << "Invalid connection connecting nodes '" << source_node_name
                   << "' and '" << target_node_name << "'." << std::endl;
         return result;
       }
 
-      // TODO! How to wire up the different types?
-//      std::string socket_name = connection.m_target_socket_name;
-//      AnimData* input_ref =
-//          target_node_accessor->GetInput<AnimData>(socket_name, nullptr);
-//      source_node_accessor->SetOutputRef(
-//          connection.m_source_socket_name,
-//          input_ref);
+      Socket* source_socket =
+          &source_node_accessor->m_outputs[connection.m_source_socket_index];
+      Socket* target_socket =
+          &target_node_accessor->m_inputs[connection.m_target_socket_index];
+      if (source_socket->m_type != target_socket->m_type) {
+        std::cerr << "Cannot connect sockets: invalid types!" << std::endl;
+      }
+
+      (*source_socket->m_value.ptr_ptr) = target_socket->m_value.ptr;
 
       size_t target_node_index = result.getAnimNodeIndex(target_node);
-
       result.m_node_inputs[target_node_index].push_back(source_node);
     }
 

tests/AnimGraphResourceTests.cc

@@ -8,41 +8,56 @@
 TEST_CASE("BasicGraph", "[AnimGraphResource]") {
   AnimGraphResource graph_resource;
 
+  graph_resource.clear();
   graph_resource.m_name = "WalkRunBlendGraph";
 
-  AnimNodeResource walk_node;
+  // Prepare graph inputs and outputs
+  size_t walk_node_index =
+      graph_resource.addNode(AnimNodeResourceFactory("AnimSampler"));
+  size_t run_node_index =
+      graph_resource.addNode(AnimNodeResourceFactory("AnimSampler"));
+  size_t blend_node_index =
+      graph_resource.addNode(AnimNodeResourceFactory("Blend2"));
+
+  AnimNodeResource& walk_node = graph_resource.m_nodes[walk_node_index];
   walk_node.m_name = "WalkAnim";
-  walk_node.m_type_name = "AnimSampler";
-  graph_resource.m_nodes.push_back(walk_node);
+  AnimNodeResource& run_node = graph_resource.m_nodes[run_node_index];
+  walk_node.m_name = "RunAnim";
+  AnimNodeResource& blend_node = graph_resource.m_nodes[blend_node_index];
+  walk_node.m_name = "BlendWalkRun";
 
-  AnimNodeResource run_node;
-  run_node.m_name = "RunAnim";
-  run_node.m_type_name = "AnimSampler";
-  graph_resource.m_nodes.push_back(run_node);
+  AnimNodeResource& graph_node = graph_resource.m_nodes[0];
+  graph_node.m_socket_accessor->RegisterInput<AnimData>("GraphOutput", nullptr);
 
-  AnimNodeResource blend_node;
-  blend_node.m_name = "BlendWalkRun";
-  blend_node.m_type_name = "Blend2";
-  graph_resource.m_nodes.push_back(blend_node);
+  REQUIRE(graph_node.m_socket_accessor->m_inputs.size() == 1);
+  REQUIRE(blend_node.m_socket_accessor->GetInputIndex("Input0") == 0);
+  REQUIRE(blend_node.m_socket_accessor->GetInputIndex("Input1") == 1);
 
   AnimGraphConnection walk_to_blend;
-  walk_to_blend.m_source_node = &walk_node;
-  walk_to_blend.m_source_socket_name = "Output";
-  walk_to_blend.m_target_node = &blend_node;
-  walk_to_blend.m_target_socket_name = "Input0";
+  walk_to_blend.m_source_node_index = walk_node_index;
+  walk_to_blend.m_source_socket_index =
+      walk_node.m_socket_accessor->GetOutputIndex("Output");
+  walk_to_blend.m_target_node_index = blend_node_index;
+  walk_to_blend.m_target_socket_index =
+      blend_node.m_socket_accessor->GetInputIndex("Input0");
   graph_resource.m_connections.push_back(walk_to_blend);
 
   AnimGraphConnection run_to_blend;
-  run_to_blend.m_source_node = &run_node;
-  run_to_blend.m_source_socket_name = "Output";
-  run_to_blend.m_target_node = &blend_node;
-  run_to_blend.m_target_socket_name = "Input1";
+  run_to_blend.m_source_node_index = run_node_index;
+  run_to_blend.m_source_socket_index =
+      run_node.m_socket_accessor->GetOutputIndex("Output");
+  run_to_blend.m_target_node_index = blend_node_index;
+  run_to_blend.m_target_socket_index =
+      blend_node.m_socket_accessor->GetInputIndex("Input1");
   graph_resource.m_connections.push_back(run_to_blend);
 
   AnimGraphConnection blend_to_output;
-  blend_to_output.m_source_node = &blend_node;
-  blend_to_output.m_source_socket_name = "Output";
-  blend_to_output.m_target_socket_name = "GraphOutput";
+  blend_to_output.m_source_node_index = blend_node_index;
+  blend_to_output.m_source_socket_index =
+      blend_node.m_socket_accessor->GetOutputIndex("Output");
+  blend_to_output.m_target_node_index = 0;
+  blend_to_output.m_target_socket_index =
+      graph_node.m_socket_accessor->GetInputIndex("GraphOutput");
   graph_resource.m_connections.push_back(blend_to_output);
 
   graph_resource.saveToFile("WalkGraph.animgraph.json");
@@ -55,19 +70,27 @@ TEST_CASE("BasicGraph", "[AnimGraphResource]") {
               << std::endl;
   }
 
-  CHECK(graph.m_nodes.size() == 3);
-  CHECK(graph.m_nodes[0]->m_node_type_name == "AnimSampler");
-  CHECK(graph.m_nodes[1]->m_node_type_name == "AnimSampler");
-  CHECK(graph.m_nodes[2]->m_node_type_name == "Blend2");
+  REQUIRE(graph.m_nodes.size() == 4);
+  REQUIRE(graph.m_nodes[0]->m_node_type_name == "BlendTree");
+  REQUIRE(graph.m_nodes[1]->m_node_type_name == "AnimSampler");
+  REQUIRE(graph.m_nodes[2]->m_node_type_name == "AnimSampler");
+  REQUIRE(graph.m_nodes[3]->m_node_type_name == "Blend2");
 
+  // connections within the graph
   AnimSamplerNode* anim_sampler_instance0 =
-      dynamic_cast<AnimSamplerNode*>(graph.m_nodes[0]);
-  AnimSamplerNode* anim_sampler_instance1 =
       dynamic_cast<AnimSamplerNode*>(graph.m_nodes[1]);
-  Blend2Node* blend2_instance = dynamic_cast<Blend2Node*>(graph.m_nodes[2]);
+  AnimSamplerNode* anim_sampler_instance1 =
+      dynamic_cast<AnimSamplerNode*>(graph.m_nodes[2]);
+  Blend2Node* blend2_instance = dynamic_cast<Blend2Node*>(graph.m_nodes[3]);
   CHECK(anim_sampler_instance0->m_output == &blend2_instance->m_input0);
   CHECK(anim_sampler_instance1->m_output == &blend2_instance->m_input1);
 
+  // connections from graph to the graph node
+  CHECK(graph.m_socket_accessor->m_inputs.size() == 1);
+  CHECK(graph.m_socket_accessor->FindInputSocket("GraphOutput"));
+  CHECK(reinterpret_cast<char*>(blend2_instance->m_output) == graph.m_input_buffer);
+
+  // check node input dependencies
   size_t anim_sampler_index0 = graph.getAnimNodeIndex(anim_sampler_instance0);
   size_t anim_sampler_index1 = graph.getAnimNodeIndex(anim_sampler_instance1);
   size_t blend_index = graph.getAnimNodeIndex(blend2_instance);