tml#window_userptr">window user pointer</a>, you can access non-global structures or objects from your callbacks.</p>
<p>To get a better feel for how the various events callbacks behave, run the <code>events</code> test program. It register every callback supported by GLFW and prints out all arguments provided for every event, along with time and sequence information.</p>
<h1><a class="anchor" id="events"></a>
Event processing</h1>
<p>GLFW needs to communicate regularly with the window system both in order 