repeatedly_execute (_always)

For example, suppose that you want a bird to fly backwards and forwards across the screen in the background. You need a way of telling the bird to move in one direction, recognise when it has finished, and tell it to move back again.

This is where repeatedly_execute and repeatedly_execute_always come in.

What's the difference between them?

The repeatedly_execute event is run on every game loop (by default this is 40 times per second), but only when the game is not blocked. That means that it will run as long as there are no current blocking animations or moves going on (ie. a Walk or Animate command where eBlock has been specified as a parameter).

On the other hand, repeatedly_execute_always is always run on every game loop, no matter whether the game is blocked or not. This comes at a price though, which is that you cannot run any blocking code within it. So if you try to script a player.Walk() command that passes the eBlock parameter -- or even just try to use a Wait(1); command, these will fail within repeatedly_execute_always.

What would I use each one for?

You would usually use repeatedly_execute for doing things that affect the player character, and repeatedly_execute_always for doing background tasks that don't directly affect the player.

For example, if your game kept track of the player's hunger, you might want to check in repeatedly_execute how long it has been since he last ate -- and if it has been more than 20 minutes, make the player character stop walking and rub his stomach. Because you want to perform a blocking animation, and you wouldn't want this to interrupt any specific cutscenes that were going on, repeatedly_execute would be the ideal place for it.

On the other hand, in the case of our bird flying across the screen, because we don't want to block the game while the bird flies, and we just want it to happen in the background, repeatedly_execute_always would be the place to put it.

How do I create them?

In main game scripts, you create your repeatedly_execute script function by just pasting it into the script as follows. In the GlobalScript.asc it is already created for you:

function repeatedly_execute()
{
  // Put your script code here
}

This is important to remember -- in a room script, you cannot simply paste in a repeatedly_execute function; you need to use the Events Pane to create it instead.

To create repeatedly_execute_always, you can simply paste it into the script as above -- but you can also paste it into room scripts. Therefore the following will work in any script, whether it be a room or a global script.

function repeatedly_execute_always()
{
  // Put your script code here
}

Can you show me an example?

Let's implement the two things we just talked about. Here's our hunger checking code:

function repeatedly_execute()
{
  // increment our timer variable (we would have created this
  // in the Global Variables editor)
  hungerTimer++;
  
  if (hungerTimer == 800)
  {
    Display("You are getting very hungry.");
    player.LockView(RUBSTOMACH);
    player.Animate(0, 5, eOnce, eBlock, eForwards);
    player.UnlockView();
  }
}

function repeatedly_execute_always()
{
  if (!cBird.Moving)
  {
    if (cBird.x < 100)
    {
      // if the bird is on the left hand side of the screen,
      // start it moving towards the right
      cBird.Walk(400, cBird.y, eNoBlock, eAnywhere);
    }
    else
    {
      // otherwise, move it towards the left
      cBird.Walk(0, cBird.y, eNoBlock, eAnywhere);
    }
  }
}