update

src/c1/circle.cpp

@@ -81,7 +81,7 @@ int main(){
         glClear(GL_COLOR_BUFFER_BIT);
         render();
         glfwSwapBuffers(window);
-        // std::this_thread::sleep_for(std::chrono::milliseconds(1000/F_PER_SECOND));
+        std::this_thread::sleep_for(std::chrono::milliseconds(1000/F_PER_SECOND));
         glfwPollEvents();
     }
     return 0;