message: allow hiding of windows from button on title bar of the window
diff: @@ -629,16 +629,19 @@ namespace ospray {
  ImGui::SetNextWindowSize(ImVec2(255,165), ImGuiCond_Always);
  auto flags = g_defaultWindowFlags | ImGuiWindowFlags_NoResize;
  - ImGui::Begin("Rendering Statistics", nullptr, flags);
  - ImGui::NewLine();
  + if (ImGui::Begin("Rendering Statistics",
  + &showWindowRenderStatistics,
  + flags)) {
  ImGui::Text("OSPRay render rate: %.1f fps", lastFrameFPS);
  + ImGui::NewLine();
  ImGui::Text("Total GUI frame rate: %.1f fps", ImGui::GetIO().Framerate);
  ImGui::Text("Total 3dwidget time: %.1f ms", lastTotalTime*1000.f);
  ImGui::Text("GUI time: %.1f ms", lastGUITime*1000.f);
  ImGui::Text("display pixel time: %.1f ms", lastDisplayTime*1000.f);
  - ImGui::Text("Variance: %.3f", renderEngine.getLastVariance());
  ImGui::NewLine();
  + ImGui::Text("Variance: %.3f", renderEngine.getLastVariance());
  + }
  ImGui::End();
  }
  @@ -646,7 +649,12 @@ namespace ospray {
  void ImGuiViewer::guiFindNode()
  {
  ImGui::SetNextWindowSize(ImVec2(400,300), ImGuiCond_FirstUseEver);
  - ImGui::Begin("Node Finder", nullptr, g_defaultWindowFlags);
  + if (!ImGui::Begin("Node Finder",
  + &showWindowFindNode,
  + g_defaultWindowFlags)) {
  + ImGui::End();
  + return;
  + }
  ImGui::NewLine();
  @@ -698,8 +706,7 @@ namespace ospray {
  {
  ImGui::SetNextWindowSize(ImVec2(500,400), ImGuiCond_FirstUseEver);
  - ImGui::Begin("SceneGraph", nullptr, g_defaultWindowFlags);
  -
  + if (ImGui::Begin("SceneGraph", &showWindowSceneGraph, g_defaultWindowFlags))
  guiSGTree("root", scenegraph);
  ImGui::End();
  