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

keprast

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

Show your event handling code and your movement code.

It only does what you tell it to. :/

keprast

#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

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

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

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));

Thread #617526. Printed from Allegro.cc