Slowdown problem « cocos2d for iPhone

cocos2d for iPhone » Programming » physics

Slowdown problem

(40 posts) (11 voices)

Started 2 years ago by pabloruiz55
Latest reply from Sama7

Tags:

12 Next »

pabloruiz55
Member

Hi!

I have the following problem,

My game is running at 55,60 fps constantly, but sometimes (especially some seconds after it starts) the fps drops, for a momment it's like it jumps some steps, then it goes back to 55 - 60 fps.

I am using chipmunk and i have tested it with cocos2d v0.72 and now on 0.8, it happens on both (i think a little more on 0.8 or at least it is more evident)

I have tried to isolate the problem, but it seems to happen "at random", i mean it does not happen when doing anything in particular or anything intensive...

I won't paste any code, because i wouldn't know what to show you since it could be anywhere, but i have already donde the following without any different result:

- Play with the chipmunk configuration: reduced steps, iterations,etc: the game goes faster overall but the random "hiccups" remain

- there are like 30 chipmunk bodies, which i create on initialization, i keep them out of screen, and use them accordingly (i have double checked that they are not created in the same place, out of screen thus increasing collisions...)
I have tried reducing the quantity to even 2 of them and the problems remains...

I can't remember what else i have tried... It isn't THAT big issue, but once, the leap was so big, the player ended out of screen... (it happened once out of 100 playthroughs, but it worries me...)

What i would like to know if there is something i am missing, or if this is some "normal" behaviour...

Sorry for the vague description and the very long post.

Thnaks!

Posted 2 years ago #
Steve Oldmeadow
Administrator

Are you playing mp3 audio files and using firmware version 3.0? If so, there is an issue where in some circumstances mp3 files are now being decoded in software rather than hardware which is causing performance problems in some games because of the extra load on the cpu.

Posted 2 years ago #
pabloruiz55
Member

Hi steve,
I am using 3.0 but every audio file i have is .wav right now...

Posted 2 years ago #
yarri
Member

Hi,

Chipmunk does automatically resize it's hash if it's "full" which may cause the problems you mentioned. You can check for this by trapping/breakpoint on calls to:
cpSpaceHashResize() or
cpHashSetResize()

Or try Box2d...

Good luck,
--yarri

Posted 2 years ago #
pabloruiz55
Member

Well, it looks like it might be it.
I placed a breakpoint in the cpHashSetResize() call and my game does not slowdown, and then sometimes the function is called... so it could be it...

Now... how can i solve it? Any ideas?
Thanks!

Posted 2 years ago #
Codemattic
Moderator

You may get better answers in the Chipmunk physics forum:

http://www.slembcke.net/forums/viewforum.php?f=1

Probably you will need to set up your hashsize ahead of time when you start your game.

sorry I couldnt give you a better answer, Codemattic

Posted 2 years ago #
Steve Oldmeadow
Administrator

I remember Carpy was having some performance issue with Chipmunk that he managed to fix. Maybe search the old Google forum for posts from him about Chipmunk performance.

Posted 2 years ago #
yarri
Member

In cpSpace.c, try different settings for default DIM_SIZE and COUNT in the cpSpaceInit() function.

It's a bit old, but this reply to my post in the Chipmunk forum by Scott gave some guidelines on performance tuning:
http://www.slembcke.net/forums/viewtopic.php?f=1&t=369&hilit=

--yarri

Posted 2 years ago #
pabloruiz55
Member

Hi! i checked carpy's issue, according to him it was resolved when he removed all manual changes to velocities...

I am not doing that anywhere...

Also i checked the post provided by yarri, i tweaked the hashes in everyway possible following the guidelines provided, but nothing...

I still have this issue... On the best possible configuration i have 60 fps, it goes down to 55, 60 if i am touching the screen. And a couple of times framerate drops to less that 30... other times a leap occurs, my game freezes for 1/2 of a second.

i noticed this issue when i switched to 3.0, before that, if there was a framerate drop it would not go under 30 fps.

Also i tried older versions of my game to see it it was because of something i added around that time. There are slowdowns in there too...

Anyway if i am the only one experiencing this, there must be something bad in my code :P

Posted 2 years ago #
brigadir
Member

I met the same frames drop. The reason was in OpenGL memory overhead - after some time when it raise above 24 MB system swaps the memory (so it unloads old textures but keeps references to them, and also it doesn't load texture immediately when you create it) - at this moment FPS drops. I made this conclusion after run my project with Instruments (OpenGL Driver & Memory Monitor).
So now, because of Cocos2d texture manager loads textures once and keeps them, I force unload old textures.

Posted 2 years ago #
coolman
Member

Pablo, try to set Airplane mode on and let us how is working now.

Posted 2 years ago #
pabloruiz55
Member

I tried turning airplane mode on, but the result is the same...
hey Brigadir how would i force unload on old textures?

Posted 2 years ago #
brigadir
Member

In Texture2D.m:
- (void) deleteFromOGL
{
if(_name)
{
glDeleteTextures(1, &_name);
// NSLog ([NSString stringWithFormat: @"Delete OGL Texture: #%d %dx%d (%dKb)", _name, _width, _height, _width * _height / 1024]);
_name = -1;
}
}

Then manually call it for all unused textures (in my case when scene is replaced).

Posted 2 years ago #
Codemattic
Moderator

Check out TextureMgr's -removeTexture: method - or if you are in 0.8 its -removeUnusedTextures method. That will delete the Texture2D objects you no longer need, and in the Texture2D's -dealloc it calls glDeleteTextures to free up opengl memory.

Posted 2 years ago #
pabloruiz55
Member

Yeah thanks i did that today, and still i have the same problem...

I think it doesn't do much since i create the textures on init and i never remove the objects from the scene, i just reuse them by moving them outside the screen and placing them back accordingly.

I am still getting some random jumps to less than 30 fps.

I am testing with instruments now to see if i can know what is called when slowdowns happen, maybe you can help me interpret the results.

Posted 2 years ago #
pabloruiz55
Member

I am running with performance tool -> core animation. There i can clearly see when my when goes for 0.1 second from 60 to 27 fps...

Where do i have to look at exactly? At the exact momment the fps is at 27? or at the momment where it was 60 and started going down?

I recorded 2 times where it happened, and when the fps is 27 and sampler shows 100% usage the functions called are:

1)
fastdirector preMainLoop
Director mainLoop
Scheduler tick
timer fire
cocosNode step_:

2)while fps is high, just before it starts declining:

texture2d(drawing) drawAtPoint

and a little further in time

EAGLView swapbuffers

Any ideas from this? A im looking in the right place at least?

Posted 2 years ago #
pabloruiz55
Member

Still trying to solve this without any luck, any idea from what i posted before? :(

Posted 2 years ago #
Steve Oldmeadow
Administrator

Pablo, I'm guessing there is something broken in 3.0, possibly with NSTimer which would explain random drops in fps for games that have their animation driven by NSTimer. The reason I'm guessing NSTimer is because there is a replacement for using it to drive animations in a future OS version that we are not supposed to talk about.

Posted 2 years ago #
Codemattic
Moderator

"The reason I'm guessing NSTimer is because there is a replacement for using it to drive animations in a future OS version that we are not supposed to talk about."

seriously, like "Fight Club"?

Posted 2 years ago #
Steve Oldmeadow
Administrator

My understanding is 3.1 is under NDA so we shouldn't be talking about it here. If you look at the devforums the 3.1 section is marked confidential.

Some people don't some bothered though http://twitter.com/Kluivers

Posted 2 years ago #
ob1
Member

I have solved a similar problem in my game.

The drops were also showing randomly, but it was due to a clipping layer in my game taxing openGL too much. It worked well until my game reached the iPhone's limits.

Nothing in instruments gave a hint whatsoever it was the problem.

Posted 2 years ago #
Codemattic
Moderator

"If you look at the devforums the 3.1 section is marked confidential." Interesting, thanks. Good to know that Apple's working on it.

"Nothing in instruments gave a hint whatsoever it was the problem." also interesting - I guess sometimes the only thing you can do is to turn off the features of your game one by one until you find the problem.

Posted 2 years ago #
pabloruiz55
Member

I chenged in my step function the code for updating chipmunk space, i just used i fixed time step of 0.02f instead of what the examples show.

I still have dropdowns in my fps but at least i am not gettin HUGE bumps, just little ones :P

Something i saw today in
http://www.cocos2d-iphone.org/wiki/doku.php/perf_test:0_8_beta
in the sprites test, subset D(all sprites outside screen), there are slowdowns with big sprites or many small ones.

In my game i am not removing the sprites from the game, i am just putting them outside of the screen and making them wait for they turn to spawn again, maybe it has to do with that, but there aren't that many of them (30 total, maybe 20 of them outside of screen at a given momment), anyway i would like to try this out.

My question is, is there a way for me not to draw what is outside of the screen?
Would it be better if i removed the texture of those sprites and then when i am about to make them appear add the texture again?

Posted 2 years ago #
SpaceHunter
Member

There's no need to reposition the sprite off the screen nor remove the texture. Have you tried to set the visible property of the sprite to 'NO' yet? In my game I initialize max 30 asteroids that move along the x-axis. When an asteroid is destroyed I simply set the visible property to NO.

Although, I have notice a decline in FPS with the Cocos2d 0.8 and 3.0 firmware. I'm still investigating the cause.

Posted 2 years ago #
DeeNiri
Member

My game used to get choppy after playing for about 10 minutes. I found these posts when I did a search for possible solutions.

Adding [[TextureMgr sharedTextureMgr] removeAllTextures]; to the dealloc method in my class files made my game run considerably smoother than it did before. Thanks to your recommendations, I am now ready to release my game :)

Posted 2 years ago #
DeeNiri
Member

Unfortunately, I am still experiencing the drop from 60 fps to 30-40 fps with cocos2d 0.7.3 for iPhone 3.0 (even after I free all my textures in each class' dealloc method). I am working to patch the memory leaks in my app in this forum thread. Please leave me a comment if you can offer any suggestions. I can only assume my game is slowing down as I play because memory is being leaked and the processor can't keep up. Does that sound logical?

Posted 2 years ago #
pabloruiz55
Member

mhhh i don't know, i still have slowdowns and there are no memory leaks...

Posted 2 years ago #
DeeNiri
Member

Ok, that's good to know. I can focus my energies on other things. If the memory leaks are not contributing to the slow down in my game, I'm not sure there's anything else I can do before I release it.

Posted 2 years ago #
pabloruiz55
Member

At least in my case:
- Memory leaks have nothing to do (the slowdown occurs even now that i removed the leaks)
- i am calling [[TextureMgr sharedTextureMgr] removeAllTextures]; where i am supposed to call it
- I am using the fastest chipmunk configuration posible...
- i am allocating all objects on init
- Music playback also does not have to do with it.

Posted 2 years ago #
DeeNiri
Member

What size are your image files? I'm using 24 bit pngs. I'm afraid I'm overloading some buffer on the iPhone that's causing the processor to lag while the graphics are rendered. I have 24 sprites in a static chipmunk shape that are affected by the accelerometer. When the game slows below the near constant 15 fps, I lose a sprite because the physics pushes it outside of the static bounds. I'm following the memory management guides in Best Practices.

If I down grade the quality of my sprites, will my game run faster? Each sprite currently averages 100 Kb. If the iPhone allocates 64Mb of RAM for the current application? That puts my game well within the bounds of the running space if I stick to the memory guidelines of "only dealloc anything you alloc init" and "only one class dealloc per class file". Right?

Posted 2 years ago #

RSS feed for this topic

12 Next »

Reply »

You must log in to post.