Started working on evaluating embedded blend trees.

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(
@@ -1021,4 +1023,38 @@ TEST_CASE_METHOD(
         embedded_connection.target_socket_name
         == 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();
 }