Many animated bitmaps on screen

totebo

Hi guys,

I'm about to start a project which will require hundreds of animated and static bitmaps on the screen at once. Apart from using a sprite sheet and set sprites outside the visible screen area to invisible (setVisible (false)), are there any tips and tricks to keep the CPU happy? Also using local variables in all loops I suppose.

Cheers,

Niclas

antix

Have a wee read of this.. https://en.wikipedia.org/wiki/Object_pool_pattern

Then look at this thread.. http://giderosmobile.com/forum/discussion/4769/simple-item-pool-class/p1

I'm using something similar in my programs and it seems to work.

Does anybody have a better way?

totebo

Pooling, nice! I suppose it would remove/reduce the overhead of creating and removing objects at the expense of memory, but not affect CPU use of objects actually "doing something"?

@sinistersoft, you had a clever way of reducing CPU in your Dungeons game I seem to remember?

antix

@totebo, yep but in the init you should create a bunch of bitmaps first. I use 256 because that seems to be a pretty good number for my programs. I hardly ever see the pool creating new bitmaps because it ran out.

@SinisterSoft, I'm keen to know your secrets too if you're keen to share :>

SinisterSoft

Nothing that tricky...

I animate split the sprites up into groups of 4 - so that each group gets it's own frame. So anything to do with animation or 'intelligence' only happens once every 4 frames.

I do movement and collision checking every frame however, if need be then I can change the animation to an explosion or whatever if there is a collision.

If there are a lot of sprites that only move every so often then I just use a tilemap. The objects stay on the tilemap and I process it in quarters for animation. This way it looks like there is a lot of movement on the screen when in reality only 80 or so sprites need to move at once. Sprites just move in/out of the tilemap system when they stop on a specific pixel boundary.

The main thing is not to allocate and deallocate things - I just hide sprites that are not in use and then if something needs to appear I set the graphic and unhide the sprite.

totebo

Thanks @sinistersoft, some great tips there.

antix

Yeah, thanks @SinisterSoft. I really like the objects moving between being moving objects and static tiles

totebo

Guys, this Pooling business is genius. My poor iPod is swimming with its head above water, for a change.