Set flags directly on Renderer class.

This removes a dependency on mjvScene from the App class.

PiperOrigin-RevId: 824983816
Change-Id: I20dd411e6359ee411f9b0b86d4442c090ba4bd5c

src/experimental/studio/app.cc

@@ -1678,8 +1678,6 @@ void App::VisualizationGui() {
 }
 
 void App::RenderingGui() {
-  mjvScene& scene = renderer_->GetScene();
-
   // Generate a list of camera names dynamically.
   std::vector<const char*> camera_names;
   camera_names.push_back("Free");
@@ -1725,7 +1723,10 @@ void App::RenderingGui() {
     ImGui::Unindent(ImGui::GetTreeNodeToLabelSpacing() / 2);
 
     for (int i = 0; i < mjNRNDFLAG; ++i) {
-      Toggle(mjRNDSTRING[i][0], scene.flags[i]);
+      mjtByte flag = renderer_->GetFlag(static_cast<mjtRndFlag>(i));
+      Toggle(mjRNDSTRING[i][0], flag);
+      renderer_->SetFlag(static_cast<mjtRndFlag>(i), flag);
+
       if (i % 2 == 0 && i != mjNRNDFLAG - 1) {
         ImGui::SameLine();
       }

src/experimental/toolbox/renderer.h

@@ -55,6 +55,10 @@ class Renderer {
   // Saves a screenshot of the simulation state into the given file.
   void SaveScreenshot(const std::string& filename, int width, int height);
 
+  // Rendering flags.
+  mjtByte GetFlag(mjtRndFlag flag) const { return scene_.flags[flag];}
+  void SetFlag(mjtRndFlag flag, mjtByte value) { scene_.flags[flag] = value; }
+
   // Returns the mjvScene used by the renderer.
   mjvScene& GetScene() { return scene_; }