There is a bug that prevents the game from working properly.

There is a bug that prevents the game from working properly.

keprast

Member #16,794

January 2018

Hello.

My game met a problem.

Very simple function:
Use 4 keyboard buttons to move the unit.

But, very unlucky ,It doesn't work properly.

The situation is:
Press the ( any button, this is an example ) up button and the unit will go up.
1. the unit will not move.
2. do not move, wait a little time, move like a rocket(It's like having superpowers).

In fact, the speed of the unit is very slow.
What happened?

========================================
Add:
It looks like a game caton. Just like some games, network delay, instant movement.
I guess it's my quadtree that consumes too much time?(Map data)
========================================
Add:
The code is below.

Edgar Reynaldo

Major Reynaldo

May 2007

Show your event handling code and your movement code.

It only does what you tell it to. :/

Eagle and Allegro 5 binaries | Older Allegro 4 and 5 binaries | Allegro 5 compile guide
King Piccolo will make it so Then I could just flip it with some sweet, sweet matrix math. In either case, I’ll ride this wagon until the wheels fall off. Thanks to those that keep it running

keprast

Member #16,794

January 2018

#SelectExpand
  1while(open_game)
  2{
al_wait_for_event(event,&ev);
  4
if (ev.type == ALLEGRO_EVENT_KEY_DOWN)
  //something
if (ev.type == ALLEGRO_EVENT_KEY_UP)
  //something

get_operation();

if (start_geme) {
  quad_tree();
 14
  //a function that takes a lot of time
  //something
 17
}
//It takes a lot of time to get here
//something

if (ev.type == ALLEGRO_EVENT_TIMER) {
   if (ev.timer.soure == animation_timer)
     //something
   if (ev.timer.soure == fps_timer) {
     al_flip_display();
}
 28}

Edgar Reynaldo

Major Reynaldo

May 2007

You need to process all events as soon as they occur. This means you can't be blocking in 'quad_tree()' while you're processing events.

Try restructuring your code so that QuadTree() is called less often. Process every event as soon as you get it. Try something like this :

#SelectExpand
  1
  2int main(int argc , char** argv) {
 
 Init();
  5
 bool quit = false;
 bool redraw = true;
 
 int ticks = 1;
 
 /// Begin processing loop
 while (!quit) {
    if (redraw) {
       Draw();
       FlipDisplay();
       redraw = false;
    }
    ALLEGRO_EVENT ev;
    while (al_get_next_event(event_queue , &ev)) {
       if (ev.type == KEYBOARD) {
          /// Handle keypresses
       }
       if (ev.type == TIMER) {
          if (ev.timer.source == LOGICTIMER) {ticks++;}
          if (ev.timer.source == FPSTIMER) {redraw = true;}
       }
    }
    while (ticks > 0) {
       Logic();
       --ticks;
    }
    QuadTree();/// This is the problem, not sure where to put this, 
               /// but you can't block with QuadTree on every event
               /// Also, try not to call it every time Logic() is run
 }
 
 Cleanup();
 38
 return 0;
 40}

Peter Hull

Member #1,136

March 2001

I wish Allegro were a bit more helpful with the main loop (for example, providing a higher level function for the common case). It's difficult to get right and, last time I looked, the Allegro example games all do it a bit differently.
Edgar - in your example I think it will spin around the loop even if there are no events. Not a big deal but it might impact power use adversely (and have the fans running etc.) Although, in this case, if quad_tree is doing a lot of work the CPU will be 100% anyway.

Edgar Reynaldo

Major Reynaldo

May 2007

Peter - yeah, I figured he would want to use 100% CPU in this case, because his QuadTree function would be taking a lot of time. I thought he wouldn't want to waste time waiting for an event if he needed to be processing quad_tree.

It can easily be altered to wait for an event.

do {
   ALLEGRO_EVENT ev;
   al_wait_for_event(q , &ev);
   
} while (!al_is_event_queue_empty(q));