Libgdx lagging

Newbie & Debugging Questions
#1

I have a created a sprite ArrayList that holds ‘enemy’ sprites like so:


ArrayList<Sprite> enemies = new ArrayList<Sprite>();

I have ran into a problem while rendering these sprites. I have a for loop looping through the array of sprites and drawing each one onto the screen, but the game lags very badly. This is the code I have:


render(){
    batch.begin();
        for(int i = 0; i < enemies.toArray().length; i++){
            enemies[i].draw(batch);
        }
    batch.end();
}

I can’t do this without the for loop, so I can’t figure what else I can do.

#2

It’s probably not the problem, but why on earth would you [icode]enemys.toArray().lengh[/icode] when you can [icode]enemys.size()[/icode]? Also I’m assuming you meant to spell “length.”

#3

Note that enemies is spelled with an i ;D
Anyways, this isn’t nearly enough code to determine why you’re lagging. Post your code files or the render method at least.

#4

Post what else is in your render method, or if that’s all, what’s in your enemy draw method?

#5

unless there are like 60k enemies or they are very big this shouldnt produce lagging by itself

also do you mean stuttering or a low stable framerate ?

#6

What’s in the enemy.draw() method?

It sounds like you are creating something big in there, like a texture.

#7

Wait a minute

enemies[i].draw(batch);

If enemies is really an ArrayList you wouldn’t be able to index it like this. You’d need to use

enemies.get(i).draw(batch);

Are you converting enemies to a bare array at some point? If you were doing that in each loop iteration I could see that being very slow.

#8

enemies.toArray() might be a very slow operation, depending on the size of the list. Since you repeat it every iteration of the loop, it might add up. Just do enemies.size()

#9

toArray() is creating a new array every draw frame, and will cause a lot of GC

#10

Yeah to get an idea: if you run the game at 120 FPS and you have 100 entities then every second you will generate 120 x 100 = 12.000 arrays of 100 items each. And this gets worse rapidly; if you have 1000 entities then you will generate 120.000 arrays per second of 1000 items each. Definitely fix this, and this could well be the source of your “lag”.

#11

definitely.
I was kinda hoping that this wasnt your real code anyway, the misspelling of length kinda meant that this is not copy paste