Fixed connection validation when one of the nodes is an embedded blend tree.

src/AnimGraph/AnimGraphResource.cc

@@ -385,32 +385,8 @@ bool BlendTreeResource::ConnectSockets(
     return false;
   }
 
-  Socket* source_socket;
-  Socket* target_socket;
-
-  if (target_node->m_node_type_name == "BlendTree") {
-    const AnimGraphResource* target_graph_resource =
-        dynamic_cast<const AnimGraphResource*>(target_node);
-    AnimNodeResource* graph_output_node =
-        target_graph_resource->m_blend_tree_resource.GetGraphInputNode();
-    target_socket = graph_output_node->m_socket_accessor->GetOutputSocket(
-        target_socket_name.c_str());
-  } else {
-    target_socket = target_node->m_socket_accessor->GetInputSocket(
-        target_socket_name.c_str());
-  }
-
-  if (source_node->m_node_type_name == "BlendTree") {
-    const AnimGraphResource* source_graph_resource =
-        dynamic_cast<const AnimGraphResource*>(source_node);
-    AnimNodeResource* graph_output_node =
-        source_graph_resource->m_blend_tree_resource.GetGraphOutputNode();
-    source_socket = graph_output_node->m_socket_accessor->GetInputSocket(
-        source_socket_name.c_str());
-  } else {
-    source_socket = source_node->m_socket_accessor->GetOutputSocket(
-        source_socket_name.c_str());
-  }
+  Socket* source_socket = GetNodeOutputSocket(source_node, source_socket_name);
+  Socket* target_socket = GetNodeInputSocket(target_node, target_socket_name);
 
   if (source_socket == nullptr) {
     std::cerr << "Cannot connect nodes: could not find source socket '"
@@ -502,6 +478,52 @@ bool BlendTreeResource::DisconnectSockets(
   return true;
 }
 
+Socket* BlendTreeResource::GetNodeOutputSocket(
+    const AnimNodeResource* node,
+    const std::string& output_socket_name) const {
+  Socket* output_socket = nullptr;
+
+  if (node->m_socket_accessor) {
+    output_socket =
+        node->m_socket_accessor->GetOutputSocket(output_socket_name.c_str());
+  }
+
+  if (output_socket == nullptr && node->m_node_type_name == "BlendTree") {
+    const AnimGraphResource* graph_resource =
+        dynamic_cast<const AnimGraphResource*>(node);
+    const BlendTreeResource& blend_tree_resource =
+        graph_resource->m_blend_tree_resource;
+    output_socket =
+        blend_tree_resource.GetGraphOutputNode()
+            ->m_socket_accessor->GetInputSocket(output_socket_name.c_str());
+  }
+
+  return output_socket;
+}
+
+Socket* BlendTreeResource::GetNodeInputSocket(
+    const AnimNodeResource* node,
+    const std::string& input_socket_name) const {
+  Socket* input_socket = nullptr;
+
+  if (node->m_socket_accessor) {
+    input_socket =
+        node->m_socket_accessor->GetInputSocket(input_socket_name.c_str());
+  }
+
+  if (input_socket == nullptr && node->m_node_type_name == "BlendTree") {
+    const AnimGraphResource* graph_resource =
+        dynamic_cast<const AnimGraphResource*>(node);
+    const BlendTreeResource& blend_tree_resource =
+        graph_resource->m_blend_tree_resource;
+    input_socket =
+        blend_tree_resource.GetGraphInputNode()
+            ->m_socket_accessor->GetOutputSocket(input_socket_name.c_str());
+  }
+
+  return input_socket;
+}
+
 bool BlendTreeResource::IsConnectionValid(
     const AnimNodeResource* source_node,
     const std::string& source_socket_name,
@@ -524,12 +546,26 @@ bool BlendTreeResource::IsConnectionValid(
     return false;
   }
 
-  // Check socket types
-  const Socket* source_socket = source_node->m_socket_accessor->GetOutputSocket(
-      source_socket_name.c_str());
-  const Socket* target_socket = target_node->m_socket_accessor->GetOutputSocket(
-      target_socket_name.c_str());
+  const Socket* source_socket =
+      GetNodeOutputSocket(source_node, source_socket_name);
+  const Socket* target_socket =
+      GetNodeInputSocket(target_node, target_socket_name);
 
+  if (source_socket == nullptr) {
+    std::cerr << "Cannot connect nodes: could not find source socket '"
+              << source_socket_name << "'." << std::endl;
+  }
+
+  if (target_socket == nullptr) {
+    std::cerr << "Cannot connect nodes: could not find target socket '"
+              << target_socket_name << "'." << std::endl;
+  }
+
+  if (target_socket == nullptr || source_socket == nullptr) {
+    return false;
+  }
+
+  // Check socket types
   if (source_socket->m_type != target_socket->m_type) {
     return false;
   }

src/AnimGraph/AnimGraphResource.h

@@ -128,6 +128,14 @@ struct BlendTreeResource {
     return m_connections;
   }
 
+  Socket* GetNodeOutputSocket(
+      const AnimNodeResource* node,
+      const std::string& output_socket_name) const;
+
+  Socket* GetNodeInputSocket(
+      const AnimNodeResource* node,
+      const std::string& input_socket_name) const;
+
   bool ConnectSockets(
       const AnimNodeResource* source_node,
       const std::string& source_socket_name,