message: restrict play button to show only w/ 4+ keyframes
diff: @@ -608,11 +608,13 @@ void MainWindow::buildUI()
  g_camPath.erase(g_camPath.begin() + g_camPathSelected);
  g_camPathSelected = std::max(0, g_camPathSelected - 1);
  }
  + if (g_camPath.size() >= 4) {
  ImGui::SameLine();
  if (ImGui::ArrowButton("play", ImGuiDir_Right)) {
  animatingPath = !animatingPath;
  g_camPathAnimIndex = 1;
  }
  + }
  for (int i = 0; i < g_camPath.size(); i++) {
  if (ImGui::Selectable(
  (std::to_string(i) + ": " + to_string(g_camPath[i])).c_str(),
  