Processes all pending events.
This function processes only those events that are already in the event queue and then returns immediately. Processing events will cause the window and input callbacks associated with those events to be called.
On some platforms, a window move, resize or menu operation will cause event
processing to block. This is due to how event processing is designed on
those platforms. You can use the
window refresh callback to redraw the contents of
your window when necessary during such operations.
Do not assume that callbacks you set will only be called in response to event processing functions like this one. While it is necessary to poll for events, window systems that require GLFW to register callbacks of its own can pass events to GLFW in response to many window system function calls. GLFW will pass those events on to the application callbacks before returning.
Event processing is not required for joystick input to work.