Capturing a keypress in an event loop

no-reply@allegro.cc (nshade) — Sun, 24 Sep 2017 10:47:14 +0000

I'm trying to capture if any key was pressed, however my event queue is kind of all over the place. (It's spanned across several c files) It's not detecting if I have a key pressed...

Because my C files are getting on the heavy side, I'll cut/paste the relevant info.

From main.c

#SelectExpand
  1ALLEGRO_TIMER *timer = NULL;
  2ALLEGRO_EVENT_QUEUE *event_queue = NULL;
  3ALLEGRO_EVENT event;
  4
  5al_install_keyboard();
  6
  7int main(int argc, char **argv)
  8{
  9  init_gfx();
 10
 11  while (1)
 12  {
 13    
 14    al_wait_for_event(event_queue, &event);
 15    
 16    if if ((event.type == ALLEGRO_EVENT_TIMER) || (event.type == ALLEGRO_EVENT_KEY_DOWN))
 17    {
 18      logics();
 19      need_redraw = true;
 20    }
 21
 22    if (need_redraw && al_event_queue_is_empty(event_queue))
 23    {
 24      al_clear_to_color(al_map_rgb_f(0, 0, 0));
 25      drawing();
 26      al_flip_display();
 27
 28    }
 29
 30  }
 31  
 32}

gfx.c

#SelectExpand
  1
  2extern ALLEGRO_TIMER *timer 
  3extern ALLEGRO_EVENT_QUEUE *event_queue 
  4extern ALLEGRO_EVENT event;
  5
  6void logics(void)
  7
  8{
  9  if (event.type == ALLEGRO_EVENT_TIMER) { printf("timer\n"); }
 10  if (event.type == ALLEGRO_EVENT_KEY_DOWN) { printf("Keyboard!\n"); }
 11  switch (title_state)
 12  {
 13    case scrolling:
 14    { ......}
 15  }
 16}

The keyboard events don't seem to be be coming though. I just see it printing "timer" on my screen. Did I for forget to get something?

no-reply@allegro.cc (beoran) — Sun, 24 Sep 2017 11:28:43 +0000

It is hard to say from your code but did you initialize your event queue with al_create_event_qyeue and register the keyboard event source with al_register_event_source?

no-reply@allegro.cc (nshade) — Sun, 24 Sep 2017 21:53:45 +0000

Whoops found my event initialization function.. Guess what was missing.. Thanks.

#SelectExpand
  1void init_events(void)
  2{
  3  // Start a timer to regulate speed.  60bps
  4  timer = al_create_timer(ALLEGRO_BPS_TO_SECS(60));
  5  al_start_timer(timer);
  6
  7  // Start the event queue to handle keyboard input and the timer
  8  event_queue = al_create_event_queue();
  9  al_register_event_source(event_queue, al_get_timer_event_source(timer));
 10  
 11  // I forgot this
 12  al_register_event_source(event_queue, al_get_keyboard_event_source());
 13}

no-reply@allegro.cc (beoran) — Sun, 24 Sep 2017 23:24:37 +0000

Well, it happens to everyone at times. Glad I could be of help.