Now I have a spinning square in the center and a clock. Kind of a weird spin but it work. We got motion.

sfmldemo/main.cpp

@@ -18,9 +18,11 @@ void ImGui_setup(sf::RenderWindow &window) {
 
 void ImGui_update(sf::RenderWindow &window, sf::Clock &deltaClock, sf::Time &tick) {
   ImGui::SFML::Update(window, deltaClock.restart());
-  ImGui::ShowDemoWindow();
-  ImGui::Begin("Hello, world!");
-
+  // ImGui::ShowDemoWindow();
+  ImGui::Begin("Clock");
+  sf::Vector2u size = window.getSize();
+  ImGui::SetWindowPos(ImVec2(size.x - 150, 0));
+  ImGui::SetWindowSize(ImVec2(150, 50));
   std::string msg = fmt::format("Time: {}\n", tick.asSeconds());
   ImGui::Button(msg.c_str());
   ImGui::End();
@@ -28,6 +30,8 @@ void ImGui_update(sf::RenderWindow &window, sf::Clock &deltaClock, sf::Time &tic
 
 void Window_update(sf::RenderWindow &window, sf::Shape &shape) {
     window.clear();
+    sf::Vector2u size = window.getSize();
+    shape.setPosition(size.x / 2, size.y / 2);
     window.draw(shape);
     ImGui::SFML::Render(window);
     window.display();
@@ -35,15 +39,21 @@ void Window_update(sf::RenderWindow &window, sf::Shape &shape) {
 
 int main() {
   fmt::print("Setting up a window for you...\n");
+  sf::ContextSettings settings;
+  settings.antialiasingLevel = 8;
+
+  sf::RenderWindow window(sf::VideoMode(1920, 1080), "Simple Game Demo", sf::Style::Default, settings);
 
-  sf::RenderWindow window(sf::VideoMode(1920, 1080), "ImGui + SFML = <3");
   // window.setFramerateLimit(60);
   window.setVerticalSyncEnabled(true);
 
   ImGui_setup(window);
 
-  sf::CircleShape shape(100.f);
-  shape.setFillColor(sf::Color::Green);
+  sf::CircleShape shape(100.f, 4);
+  shape.setFillColor(sf::Color(150, 50, 250));
+  shape.setOutlineThickness(10.f);
+  shape.setOutlineColor(sf::Color(250, 150, 100));
+
   sf::Clock deltaClock;
   sf::Clock clock;
   sf::Time tick = clock.getElapsedTime();
@@ -67,6 +77,7 @@ int main() {
       if (event.type == sf::Event::Closed) {
         fmt::print("Exiting...\n");
         window.close();
+        thread.terminate();
       }
     }
 
@@ -75,6 +86,8 @@ int main() {
       tick = since;
     }
 
+    shape.rotate(1);
+
     ImGui_update(window, deltaClock, tick);
     Window_update(window, shape);
   }