Timing and Bitmap Troubles

oobtim

sigh :'(

Been fiddling with my timers and main loop with regards to the timers and now have a loop which boils down to:

#SelectExpand
   1while(!doExit)
{
  //test for an event
  bool get_event = al_wait_for_event_until(event_queue, &ev, &timeout);
   5
  //trigger a redraw or update
  if(ev.type == ALLEGRO_EVENT_TIMER)
  {
    if(ev.timer.source == animTimer)
    {
      redraw = true;
    }
    else if(ev.timer.source == updateTimer)
    {
      update = true;
    }
  }else if(ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE) {
    break;
  }else if(ev.type == ALLEGRO_EVENT_KEY_DOWN)
  {
       switch(ev.keyboard.keycode) {
          case ALLEGRO_KEY_UP:
            key[KEY_UP] = true;
            break;
          case ALLEGRO_KEY_DOWN:
            key[KEY_DOWN] = true;
            break;
          case ALLEGRO_KEY_LEFT:
            key[KEY_LEFT] = true;
            break;
          case ALLEGRO_KEY_RIGHT:
            key[KEY_RIGHT] = true;
            break;
          case ALLEGRO_KEY_1:
            player.playerSpeed += 0.1; //purely for testing
            break;
          case ALLEGRO_KEY_2:
            player.playerSpeed -= 0.1; //purely for testing
            break;
       }
  41
  }else if(ev.type == ALLEGRO_EVENT_KEY_UP)
  {
    //test if a key has been released
       switch(ev.keyboard.keycode) {
          case ALLEGRO_KEY_UP:
             key[KEY_UP] = false;
             break;
  49
          case ALLEGRO_KEY_DOWN:
             key[KEY_DOWN] = false;
             break;
  53
          case ALLEGRO_KEY_LEFT:
             key[KEY_LEFT] = false;
             break;
  57
          case ALLEGRO_KEY_RIGHT:
             key[KEY_RIGHT] = false;
             break;
  61
          case ALLEGRO_KEY_ESCAPE:
             doExit = true;
             break;
      }
  }
  67
  //game logic
  if(al_is_event_queue_empty(event_queue) && update){
    player.update(key); //tells the player what key has been pressed
  71
    //will they hit something if they move using this key?
    if(playerBGCollision(player)){
        player.hasCollided(); //if so make them stand still (i.e. velocity == 0)
    }
  76
    player.move();   //update position variables
    update = false;
  }
  80
  //drawing
  if(al_is_event_queue_empty(event_queue) && redraw) {
  83
    al_clear_to_color(al_map_rgb(0,0,0));              //clear
    MapDrawBG(plotMapx,plotMapy,0,0,SWIDTH,SHEIGHT);
    player.plot(plotMapx, plotMapy);
    MapDrawFG(plotMapx,plotMapy,0,0,SWIDTH,SHEIGHT,0);
  88
    al_flip_display();
  90
    redraw = false;
  }
  93
}
al_destroy_display(display);
al_destroy_event_queue(event_queue);
return 0;
  98};

From reading forums this was said to be the recommended way of carrying out the game loop (if you haven't noticed it is also based on the Allegro 5 tutorials). But for some reason there is a lag in the timing (speeds up and down), not big, but noticeable. Plus the screen flickers slightly as it scrolls.

I thought that this would be down to loading memory bitmaps rather than video bitmaps. But they are only a few 100kB! I loaded the bitmaps for the player sprite AFTER I created the display anyway to make them video but to no avail. I checked the flags of the bitmaps and they came out with a flag that I couldn't identify.

So...

Is there something wrong with my loop?
Why would my bitmaps say they have a flag of int value 1056 when I check? What type of bitmaps are they?

l j

Flags are stored bitwise
You must use something along these lines:

if (myFlags & FLAG_SOME_FLAG)
{
    // Flag is enabled
}

oobtim

Thank you, that sorts out whether I have video/memory bitmaps

Anything wrong with my loop though, as the glitch still remains?:-/

Is there something wrong with the way the updates and redraws are called? Updates and redraws are done 60 times a second and I have a separate timer for each.

EDIT

Sorted it Needed to use interpolation to get things running smoothly. That'll teach me to code after a few beers hic :-[

Thread #610349. Printed from Allegro.cc