Moved clear to refresh callback.

tests/events.c

@@ -236,6 +236,9 @@ static int window_close_callback(GLFWwindow window)
 static void window_refresh_callback(GLFWwindow window)
 {
     printf("%08x at %0.3f: Window refresh\n", counter++, glfwGetTime());
+
+    glClear(GL_COLOR_BUFFER_BIT);
+    glfwSwapBuffers();
 }
 
 static void window_focus_callback(GLFWwindow window, int activated)
@@ -371,11 +374,7 @@ int main(void)
     printf("Main loop starting\n");
 
     while (glfwIsWindow(window) == GL_TRUE)
-    {
-        glClear(GL_COLOR_BUFFER_BIT);
-        glfwSwapBuffers();
         glfwWaitEvents();
-    }
 
     glfwTerminate();
     exit(EXIT_SUCCESS);