add more frameTick() tests and clean up

src/polyscope.cpp

@@ -249,10 +249,7 @@ ImGuiContext* getCurrentContext() { return contextStack.empty() ? nullptr : cont
 void frameTick() {
 
   // Make sure we're initialized
-  if (!state::initialized) {
-    exception("must initialize Polyscope with polyscope::init() before calling polyscope::frameTick().");
-  }
-
+  checkInitialized();
   render::engine->showWindow();
 
   mainLoopIteration();
@@ -817,7 +814,7 @@ void draw(bool withUI, bool withContextCallback) {
   }
 
   // Execute the context callback, if there is one.
-  // This callback is Polyscope implementation detail, which is distinct from the userCallback (which gets called above)
+  // This callback is a Polyscope implementation detail, which is distinct from the userCallback (which gets called above)
   if (withContextCallback && contextStack.back().callback) {
     (contextStack.back().callback)();
   }

test/src/basics_test.cpp

@@ -33,6 +33,18 @@ TEST_F(PolyscopeTest, FrameTick) {
   }
 }
 
+TEST_F(PolyscopeTest, FrameTickWithImgui) {
+
+  auto showCallback = [&]() { ImGui::Button("do something"); };
+  polyscope::state::userCallback = showCallback;
+
+  for (int i = 0; i < 5; i++) {
+    polyscope::frameTick();
+  }
+
+  polyscope::state::userCallback = nullptr;
+}
+
 // We should be able to nest calls to show() via the callback. ImGUI causes headaches here
 TEST_F(PolyscopeTest, NestedShow) {
 
@@ -43,6 +55,17 @@ TEST_F(PolyscopeTest, NestedShow) {
   polyscope::state::userCallback = nullptr;
 }
 
+TEST_F(PolyscopeTest, NestedShowWithFrameTick) {
+
+  auto showCallback = [&]() { polyscope::show(3); };
+  polyscope::state::userCallback = showCallback;
+
+  for (int i = 0; i < 3; i++) {
+    polyscope::frameTick();
+  }
+
+  polyscope::state::userCallback = nullptr;
+}
 
 // Make sure that creating an empty buffer does not throw errors
 TEST_F(PolyscopeTest, EmptyBuffer) {