Question

im making a simple android game at the moment and was wondering how i can optimize my Enemy spawner, or if i dont have to.

At the moment, i just want to spawn enemies, more as the level goes on. The Game is nothin fancy, just one screen with – i would guess – max. 20 at a time on it.

So my approach is:

ArrayList<Enemy> enemies = new ArrayList(); 

I have an ArrayList where i will store all my spawned enemies (from the same class).
Now in the main update function i have the following:

  for (Enemy en : enemies){
        en.update();
    }

This would be for the position-update, now i maybe have to run a second time through the cycle to determine wich of the enemies can be deleted, because it is destroyed.

Is this the most common and effective way for a simple game?

Answer 1

Try adding a property to the enemy called “dead” or “disposed”.
So you can keep track of which enemies needs to be released doing:

for (Enemy en : enemies)
{
    if (en.isDead() == true)
    {
        // Remove en from enemies. 
        // You'll probably need to use a "for" here keeping track of the last 
        // element when deleting one. So you can continue checking/updating 
        // enemies.
        continue;
    }
    en.update();
}

You can add effects to if you don’t want it to simply “dissapear” from the screen:

for (Enemy en : enemies)
{
    if (en.isDead() == true)
    {
        en.startFadeOut();
    }
    else if (en.isFadeFinished())
    {
        // guessing some alpha channel property.
        en.setAlpha(en.getAlpha() - 0.1 * ticks);
        if (en.getAlpha() <= 0)
        {
            en.setFadeFinished(true);
        }
    }
    en.update();
}

of course you’ll need to put this logic inside the update of enemy class. This is just an idea.