 
 	// make context current
 	glfwMakeContextCurrent(window);
+
+	// turn off vsync
+	glfwSwapInterval(0);
 }
 
 Application::~Application(void)

		// calculate delta time
		float delta = (float)(glfwGetTime() - time);
		time = glfwGetTime();

		// update process
		update(delta);


	// main loop
	double time = glfwGetTime();
	int sec = 0;
	while (!glfwWindowShouldClose(window))
	{
		// update viewport
