Would cocos2d help me? (performance with a bunch of overlaying images)

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Would cocos2d help me? (performance with a bunch of overlaying images)

(13 posts) (6 voices)

Started 2 years ago by ryanashcraft
Latest reply from ryanashcraft

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ryanashcraft
Member

Hi! I'm the developer of a new app called Playing Cards that is a peer2peer virtual deck of cards. Right now I'm starting the process for version 2.0 and was looking for some answers. I have been doing a lot of research in this topic and I've played around with cocos2d but I can't find the right answer.

The whole problem is a huge performance hit with a bunch of UIImageViews (cards) overlaying each other. The way I try to minimize this performance hit now is by limiting the maximum number of UIImageViews to 10. But now I start wanting to do stuff that involves all 52 UIImageViews (cards). Would cocos2d provide a way to show all 52 cards, and be able to animate each of them without a huge performance hit? And if so, what would I use in cocos2d to achieve this? Sprites? AtlasSprites? The documentation for cocos2d is not clear. I'm hoping one of you could help me figure this out, because I know it is possible.

Thanks!

Posted 2 years ago #
cublah
Member

My guess is yes, if you were using UIImageViews then I guess you are using Quartz and that can get pretty slow with a lot of images, Cocos2d is based around OpenGL and is much faster for printing images.

Posted 2 years ago #
ryanashcraft
Member

Well I've got a project up where I've added 52 card sprites, and the FPS drops down to around 10.0 (versus where there is one card the FPS is around 60.0). How can I improve this?

Posted 2 years ago #
jd
Member

Look into AtlasSprite.

Posted 2 years ago #
ryanashcraft
Member

From this I see absolutely no improvement in FPS. What am I missing?

AtlasSpriteManager *cards = [AtlasSpriteManager spriteManagerWithFile:@"card_back.png"];

AtlasSprite *card;
for (int i = 0; i < 52; i++) {
card = [cards createSpriteWithRect:CGRectMake(0.0, 0.0, 200.0, 272.0)];
card.position = ccp( size.width /2, size.height/2 );
[cards addChild:card];
}

[self addChild:cards];

Posted 2 years ago #
jd
Member

When you get a full game shell, you should do the image creation like you have there at loading time . Then in your game you would do the [self addChild:cards]. Once you created all the sprites in the manager, you never have to create them again. You just call them when you need them.

Posted 2 years ago #
ryanashcraft
Member

The problem seems to not be the loading process of the sprites, but the displaying. For example, if I move the position of the sprites partially out of bounds from the layer, the FPS jumps up significantly. What's causing this drain? If I set the opacity of the cards to 0.0, the FPS is still the same.

Again, thanks so much for your help. I really want to get beyond over this hurdle.

Posted 2 years ago #
jd
Member

Another "trick" you can do is give them all a position off screen. When you need them just update the position. It's possible adding 52 sprites to a layer at once is the slowdown. So if they are already added and you update the positions later, it may be faster. Maybe you can post some more code because this doesn't seem like it should be a huge performance hit.

Posted 2 years ago #
rbrooky
Member

@ryanashcraft: what if you set the visibility property of each card to FALSE until you need it?

[card setVisible = NO];

Not sure if it works but it maybe worth a try

Posted 2 years ago #
ryanashcraft
Member

@rbrooky

Yeah it works but my point is that I want them all visible all the time. If this isn't possible then there is no reason to switch to cocos2d/OpenGL es

Posted 2 years ago #
crmagicxxx
Member

As I can see your cards are very large images 200x272. So the problem is refreshing almost the whole screen 52 times. I still can't understand why you need whole 52 cards to be shown when only one card with that dimension can be seen on iPhone screen? You need to optimize better your code and display only card you need.

Posted 2 years ago #
PhilM
Member

agree with crmagicxxx, you've got lots of very large sprites. See what fps you get if you say add 1/4 or 1/2 of them, just as a measuring stick on performance.

If most are being overlapped alot of the time, it might be better to create a single blank/template card, and then only add the face of the card when its visible? I'm intrigued how your displaying 52 200x272 images at the same time?

Posted 2 years ago #
ryanashcraft
Member

Well you all have pretty much answered my question. I really appreciate all your input. Basically, I just have to creatively implement a method to make it look like there's a bunch of cards. I didn't realize that just the frame of Sprite makes such a huge impact on the performance. What I might do is minimize the frame height of the sprites that are only partially visible and then maximize them when they are on top and fully visible.

Thanks again everybody! I've learned a lot!

Posted 2 years ago #

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