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Performance issues

(9 posts) (4 voices)

Started 1 year ago by Dunc
Latest reply from Dunc

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Dunc
Member

Hi all,

Another week has passed, and I'm very nearly finished my first cocos2d project. Everything was running fine until I started introducing other scenes (like a menu scene). Now I'm getting some choppy performance - but only if I launch my main game scene from my main menu scene. I think the way I've implemented the main game scene is perhaps not a particularly efficient approach. Here's how I'm currently doing things:

My GameScene contains a whole bunch of animated characters running around the screen. These are frequently removed and others replace them, so there is no runaway build-up of sprites at any one time. Each of these sprites is actually a Layer subclass, containing an AtlastSpriteManager, and an AtlasSprite (I started this last week in 0.82 - not had a chance to re work it for 0.99 yet). Each instance of this sprite can be one of 3 randomly selected types (ie, they use one of 3 different sprite sheets).

This was working fine until I started launching the GameScene from my MainMenuScene. Now the whole thing intermittently freezes for a split second every time a new sprite is spawned (I think).

Is it possible that whatever image caching was taking place before is now not happening? How should I be structuring things?

I did try creating a single AtlasSpriteManager property for each sprite sheet in my GameScene, and then passing a reference to the GameScene into the sprite objects, and sticking all the sprites in to these shared AtlasSpriteManagers, but after a few spawns the game would crash.

Any advice would be great, as I'm just making this up as I go along, and would love to know how other people are doing things!

Cheers,

Dunc.

Posted 1 year ago #
Karl
Member
A few things:

1. If you are loading each sprite into a different AtlasSpriteManager, then you are losing all AtlasSprite performance benefits, and actually incurring a penalty on top of that. AtlasSprites get a performance boost only when you have multiple sprites attached to the same sprite manager. If your game mechanics don't work under those constraints, then you're better off just using normal sprites.

2. If you use up your memory, the default cocos2d app delegate template is set to flush the image cache. This will cause the next attempt to load a previously cached image to load from disk, hurting performance. I always make a point of adding a log entry to make sure I don't miss a memory warning. If applicationDidReceiveMemoryWarning is getting called, you've got big problems and need to rethink your program structure or check for memory mismanagement.
```
- (void)applicationDidReceiveMemoryWarning:(UIApplication *)application {
	NSLog(@"MEMORY WARNING");
	[[ResourcePreloader sharedInstance] interruptPreload];
	[[ResourceCache sharedInstance] removeUnusedObjects];
}
```
3. You should probably double-check to make sure your old scene is actually being released. An innocuous backpointer could cause the entire object tree to remain in memory even though you believe it to be released. Definitely run your app through Instruments to see what's actually in memory.
Posted 1 year ago #
shadaz
Member

I was going to say something similar to Karl regarding item #3. I put a NSLog on the deallocs to make sure they are getting released. I had one instance (when i first started out with cocos) in which I used an NSTimer and it prevented my scene from being dealloc, i switched to schedule instead and the scene got dealloc'd and everything was fine.

Posted 1 year ago #
Dunc
Member

Thanks for the advice guys. I'll check to see if the main menu scene is deallocating properly, and I'll fire up instruments. I wasn't sure if I'd be getting any benefits from AtlasSprites/manager, but there isn't really any other way to structure things I don't think, due to having to keep the z depth's in order of sprite y position (to give an impression of depth). Of course, this wouldn't be a problem if I was just using one sprite sheet, but I'm any of my sprites can use one of 3 sprite sheets.

Thanks again.
Dunc.

Posted 1 year ago #
Dunc
Member

Odd - no memory warnings. The main menu scene gets deallocated every time it's replaced with the game scene. So nothing obviously amiss there... I'm about to run it through instruments to see if anything jumps out at me.

D.

Posted 1 year ago #
Dunc
Member

Okay, so this had nothing to do with sprites, and everything to do with my audio engine! I think.

Thanks for your helps anyways :)

D.

Posted 1 year ago #

This is what I use for fake isometric sprite ordering. This one works on regular sprites, but you can subclass AtlasSpriteManager to do something similar.

//
//  YOrderedSpriteManager.h
//
//  Created by Karl Stenerud on 09/11/09.
//  Use it any way you want.  No warranties implied.
//

#import "cocos2d.h"

/** YOrderedSpriteManager is a CocosNode that renders its children based on their Y position.
 * Children with a lower Y value will be rendered later.
 */
@interface YOrderedSpriteManager : CocosNode
{
}

/** Create a manager */
+ (id) manager;

@end

#import "YOrderedSpriteManager.h"

@interface YOrderedSpriteManager (Private)

-(void) sortChildrenByYPosition;

@end

@implementation YOrderedSpriteManager

+ (id) manager
{
	return [[[self alloc] init] autorelease];
}

-(void) visit
{
	if(!visible)
	{
		return;
	}

	[self sortChildrenByYPosition];

	for(CocosNode* child in children)
	{
		[child visit];
	}
}

// Sorts the children based on their Y position (lower Y = rendered later)
-(void) sortChildrenByYPosition
{
	// Sprites will always be partially ordered after the first sort, so use insert sort.

	Sprite* testValue;
	int length = children.count;
	int i;

	for(int j = 1; j < length; j++)
	{
		testValue = [[children objectAtIndex:j] retain];
		for(i = j-1; i >= 0 && ((Sprite*)[children objectAtIndex:i]).position.y < testValue.position.y; i--)
		{
			[children replaceObjectAtIndex:i+1 withObject:[children objectAtIndex:i]];
		}
		[children replaceObjectAtIndex:i+1 withObject:testValue];
		[testValue release];
	}
}

@end

Posted 1 year ago #

Codemattic
Moderator

I wonder if you could use the NSMutableArray children and the method -sortUsingFunction:context: to sort faster? Im not sure cocos will like direct reordering of children, but Im not sure.

Posted 1 year ago #
Dunc
Member

Hi guys,

Sorry I only just saw these replies (must check to see if you can set up email notifications on this forum)...

Thanks for that depth ordering solution - I may well nab that for a forthcoming project...

It's all working beautifully now though - the choppiness was actually caused by my use of multiple instances of the AVAudioPlayer. Switched to using a shared instance in the AppDelegate, and just re-initializing it with new MP3s, and everything flies now.

Thanks again.

D.

Posted 1 year ago #

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