Properly store and restore node positions in editor.

src/AnimGraph/AnimGraphEditor.cc

@@ -160,7 +160,11 @@ void SkinnedMeshWidget(SkinnedMesh* skinned_mesh) {
 void AnimGraphEditorRenderSidebar(
     BlendTreeResource& blend_tree_resource,
     AnimNodeResource* node_resource) {
-  ImGui::Text("[%s]", node_resource->m_node_type_name.c_str());
+  ImGui::Text(
+      "[%s (%2.2f, %2.2f)]",
+      node_resource->m_node_type_name.c_str(),
+      node_resource->m_position[0],
+      node_resource->m_position[1]);
 
   char node_name_buffer[256];
   memset(node_name_buffer, 0, sizeof(node_name_buffer));
@@ -263,7 +267,10 @@ void AnimGraphEditorRenderSidebar(
 }
 
 void AnimGraphEditorClear() {
-  sEditorState.hierarchyStack.clear();
+  if (ax::NodeEditor::GetCurrentEditor() != nullptr) {
+    ax::NodeEditor::ClearSelection();
+  }
+
   delete sEditorState.rootGraphResource;
 
   sEditorState.rootGraphResource = new AnimGraphResource();
@@ -271,9 +278,11 @@ void AnimGraphEditorClear() {
   sEditorState.rootGraphResource->m_graph_type_name = "BlendTree";
   sEditorState.rootGraphResource->m_blend_tree_resource.InitGraphConnectors();
 
+  sEditorState.hierarchyStack.clear();
   sEditorState.hierarchyStack.push_back(sEditorState.rootGraphResource);
   sEditorState.hierarchyStack[sEditorState.hierarchyStackIndex] =
       sEditorState.hierarchyStack.back();
+  sEditorState.hierarchyStackIndex = 0;
 }
 
 void AnimGraphEditorUpdate(ax::NodeEditor::EditorContext* context) {
@@ -287,6 +296,7 @@ void AnimGraphEditorUpdate(ax::NodeEditor::EditorContext* context) {
     sEditorState.rootGraphResource->SaveToFile("editor_graph.json");
   }
   if (ImGui::Button("Load")) {
+    AnimGraphEditorClear();
     sEditorState.rootGraphResource->LoadFromFile("editor_graph.json");
     sEditorState.isGraphLoadedThisFrame = true;
   }
@@ -348,18 +358,15 @@ void AnimGraphEditorUpdate(ax::NodeEditor::EditorContext* context) {
   //
   ax::NodeEditor::Begin("Graph Editor");
 
-  for (size_t node_id = 0,
+  for (size_t node_index = 0,
               n = sEditorState.hierarchyStack[sEditorState.hierarchyStackIndex]
                       ->m_blend_tree_resource.GetNumNodes();
-       node_id < n;
+       node_index < n;
-       node_id++) {
+       node_index++) {
     AnimNodeResource* node_resource =
         sEditorState.hierarchyStack[sEditorState.hierarchyStackIndex]
-            ->m_blend_tree_resource.GetNode(node_id);
+            ->m_blend_tree_resource.GetNode(node_index);
-
+    ax::NodeEditor::NodeId node_id(node_resource);
-    if (node_id == 0 || node_id == 1) {
-      // continue;
-    }
 
     if (sEditorState.isGraphLoadedThisFrame) {
       ax::NodeEditor::SetNodePosition(
@@ -377,7 +384,7 @@ void AnimGraphEditorUpdate(ax::NodeEditor::EditorContext* context) {
       Socket& socket = node_inputs[j];
       ax::NodeEditor::BeginPin(
           NodeIndexAndSocketIndexToInputPinId(
-              static_cast<int>(node_id),
+              static_cast<int>(node_index),
               static_cast<int>(j)),
           ax::NodeEditor::PinKind::Input);
       ImGui::Text("%s", socket.m_name.c_str());
@@ -392,7 +399,7 @@ void AnimGraphEditorUpdate(ax::NodeEditor::EditorContext* context) {
       Socket& socket = node_outputs[j];
       ax::NodeEditor::BeginPin(
           NodeIndexAndSocketIndexToOutputPinId(
-              static_cast<int>(node_id),
+              static_cast<int>(node_index),
               static_cast<int>(j)),
           ax::NodeEditor::PinKind::Output);
       ImGui::Text("%s", socket.m_name.c_str());
@@ -597,22 +604,32 @@ void AnimGraphEditorUpdate(ax::NodeEditor::EditorContext* context) {
       AnimGraphEditorRenderSidebar(
           sEditorState.hierarchyStack[sEditorState.hierarchyStackIndex]
               ->m_blend_tree_resource,
-          sEditorState.hierarchyStack[sEditorState.hierarchyStackIndex]
+          selected_node_id.AsPointer<AnimNodeResource>());
-              ->m_blend_tree_resource.GetNode(selected_node_id.Get()));
     }
   }
 
   ImGui::Columns(1);
 
+  // Clear flag, however it may be re-set further down when handling double
+  // clicking into subgraphs.
+  sEditorState.isGraphLoadedThisFrame = false;
+
+  //
+  // Handle double click into subgraphs
+  //
   ax::NodeEditor::NodeId double_clicked_node_id =
       ax::NodeEditor::GetDoubleClickedNode();
   if (!double_clicked_node_id.Invalid) {
     AnimNodeResource* clicked_node_resource =
-        sEditorState.hierarchyStack[sEditorState.hierarchyStackIndex]
+        double_clicked_node_id.AsPointer<AnimNodeResource>();
-            ->m_blend_tree_resource.GetNode(double_clicked_node_id.Get());
+
-    if (clicked_node_resource->m_node_type_name == "BlendTree") {
+    if (clicked_node_resource != nullptr
+        && clicked_node_resource->m_node_type_name == "BlendTree") {
       AnimGraphResource* clicked_graph_resource =
           dynamic_cast<AnimGraphResource*>(clicked_node_resource);
+
+      assert(clicked_graph_resource != nullptr);
+
       if (sEditorState.hierarchyStack.size()
               > sEditorState.hierarchyStackIndex + 1
           && sEditorState.hierarchyStack[sEditorState.hierarchyStackIndex + 1]
@@ -625,12 +642,12 @@ void AnimGraphEditorUpdate(ax::NodeEditor::EditorContext* context) {
         sEditorState.hierarchyStackIndex++;
       }
 
+      sEditorState.isGraphLoadedThisFrame = true;
       ax::NodeEditor::ClearSelection();
     }
   }
 
   ax::NodeEditor::SetCurrentEditor(nullptr);
-  sEditorState.isGraphLoadedThisFrame = false;
 }
 
 void AnimGraphEditorGetRuntimeGraph(AnimGraphBlendTree& blend_tree) {

src/AnimGraph/AnimGraphResource.cc

@@ -256,6 +256,8 @@ static json sAnimGraphResourceBlendTreeToJson(
   result["name"] = anim_graph_resource.m_name;
   result["type"] = "AnimNodeResource";
   result["node_type"] = "BlendTree";
+  result["position"][0] = anim_graph_resource.m_position[0];
+  result["position"][1] = anim_graph_resource.m_position[1];
 
   const BlendTreeResource& blend_tree_resource =
       anim_graph_resource.m_blend_tree_resource;
@@ -307,6 +309,8 @@ static bool sAnimGraphResourceBlendTreeFromJson(
   result_graph_resource->m_graph_type_name = "BlendTree";
   result_graph_resource->m_node_type_name = "BlendTree";
   result_graph_resource->m_name = json_data["name"];
+  result_graph_resource->m_position[0] = json_data["position"][0];
+  result_graph_resource->m_position[1] = json_data["position"][1];
 
   // Load nodes
   for (size_t i = 0, n = json_data["nodes"].size(); i < n; i++) {