Question

I’ve got a problem in my cocos2d game: In the Game’s level layer I’ve 3-5 big sprites for background (1920*640 ~100kb each) ~ 400-500kb in each level. When I switch between menu and various game’s level 4-5 times the game crashes to main IPhone menu

[[CCDirector sharedDirector] replaceScene:transition];

without this big sprites all work perfect!

-(id) init
{
 ....   
    if( (self=[super init])) {
_spriteBGLevel1 = [CCSprite spriteWithFile: [NSString stringWithFormat:@"level_fon_%i_1.png", _currentLevel]]; 
_spriteBGLevel1.anchorPoint = ccp(0, 0);
_spriteBGLevel1.position = CGPointMake(0.0, 0.0); 
[self addChild:_spriteBGLevel1 z:-5];
_spriteBGLevel2 = [CCSprite spriteWithFile: [NSString stringWithFormat:@"level_fon_%i_2.png", _currentLevel]]; 
_spriteBGLevel2.anchorPoint = ccp(0, 0);
_spriteBGLevel2.position = CGPointMake(0.0, 0.0); 
[self addChild:_spriteBGLevel2 z:-5];
_spriteBGLevel3 = [CCSprite spriteWithFile: [NSString stringWithFormat:@"level_fon_%i_3.png", _currentLevel]]; 
_spriteBGLevel3.anchorPoint = ccp(0, 0);
_spriteBGLevel3.position = CGPointMake(0.0, 0.0); 
[self addChild:_spriteBGLevel3 z:-5];        

....


- (void) dealloc
{
....
    _spriteBGLevel1=nil;
    _spriteBGLevel2=nil;
    _spriteBGLevel3=nil;
    [super dealloc];
}

Background.m

#import "Background.h"
#import "GameConfig.h"
#import "XMLReader.h"
#import "CCParallaxNode-Extras.h"
#import "SettingsManager.h"


@implementation Background

@synthesize backgrounds=_backgrounds;
@synthesize backgroundNode=_backgroundNode;

+(id) scene
{
    CCScene *scene = [CCScene node];

    Background *layer = [Background node];

    [scene addChild: layer];

    return scene;
}

-(id) init
{
    if ((self = [super init]))
    {

        CGSize screenSize = [[CCDirector sharedDirector] winSize];

        int currentLevel = [[SettingsManager sharedSettingsManager] getCurrentLevel];

        _backgroundNode = [CCParallaxNode node];
        _backgroundNode.anchorPoint = CGPointMake(0, 0);
        _backgroundNode.position = CGPointMake(0, 0);
        [self addChild:_backgroundNode z:-1];

        NSData *xmlData = [NSData dataWithContentsOfFile:[[NSBundle bundleForClass:[self class]] pathForResource:@"gameScene" ofType:@"xml"]];

        NSError *error = nil;

        NSDictionary *dictionary = [XMLReader dictionaryForXMLData:xmlData error:&error];
        NSDictionary *levelsDict = [dictionary valueForKeyPath:@"levels.level"];
        NSDictionary *levelDict;

        _backgrounds = [[[NSMutableArray alloc] init] retain];

//        [[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile: [NSString stringWithFormat:@"level_fon_%i.plist", currentLevel]];


        for (levelDict in levelsDict)
        {

            int idLevel = [[levelDict valueForKeyPath:@"id"] intValue];
            if(idLevel==currentLevel)
            {
                NSDictionary *fonsDict = [levelDict valueForKeyPath:@"background.fon"];

                NSDictionary *fonDict;
                for (fonDict in fonsDict){

                    NSString *name=[fonDict valueForKeyPath:@"name"];
                    int zIndex=[[fonDict valueForKeyPath:@"z"] intValue];
                    float ratio=[[fonDict valueForKeyPath:@"ratio"] floatValue];
                    float offsetx=[[fonDict valueForKeyPath:@"offsetx"] floatValue];
                    float offsety=[[fonDict valueForKeyPath:@"offsety"] floatValue];
                    if(zIndex<0)
                    {    
                    //CCTexture2D* tex = [[CCTextureCache sharedTextureCache] addImage:[NSString stringWithFormat:@"%@", name]];

                    //CCSprite *fon_level_1 = [CCSprite spriteWithSpriteFrameName: [NSString stringWithFormat:@"%@", name]];
                    //CCSprite *fon_level_2 = [CCSprite spriteWithSpriteFrameName: [NSString stringWithFormat:@"%@", name]];
                    //CCSprite *fon_level_1 = [CCSprite spriteWithTexture:tex];
                    //CCSprite *fon_level_2 = [CCSprite spriteWithTexture:tex];

                    fon_level_1 = [CCSprite spriteWithFile:[NSString stringWithFormat:@"%@", name]];
                    fon_level_2 = [CCSprite spriteWithFile:[NSString stringWithFormat:@"%@", name]];

                    fon_level_1.anchorPoint = CGPointMake(0, 0);
                    fon_level_1.position = CGPointMake(0, 0);
                    fon_level_2.anchorPoint = CGPointMake(0, 0);
                    fon_level_2.position = CGPointMake(0, 0);
                    //[_backgroundNode addChild:fon_level_1 z:zIndex parallaxRatio:ccp(ratio, ratio) positionOffset:ccp(offsetx, offsety*screenSize.height)];
                    //[_backgroundNode addChild:fon_level_2 z:zIndex parallaxRatio:ccp(ratio, ratio) positionOffset:ccp(fon_level_1.contentSize.width, offsety*screenSize.height)];
                    [_backgrounds addObject:fon_level_1];
                    [_backgrounds addObject:fon_level_2];

                        fon_level_1=nil;
                        fon_level_2=nil;
                    }    
                }
                break;
            }    
        }

        NSLog(@"count: %d",_backgrounds.count);
        [self scheduleUpdate];
    }
    return self;
}
- (void)scheduleUpdate
{
    [self schedule:@selector(updateBackgroud:)];
}
-(void) updateBackgroud:(ccTime)delta
{
    CGPoint backgroundScrollVel = ccp(-1000, 0);

    _backgroundNode.position = ccpAdd(_backgroundNode.position, ccpMult(backgroundScrollVel, delta));

    for (CCSprite *background in _backgrounds) {
        if (([_backgroundNode convertToWorldSpace:background.position].x+background.contentSize.width/10) < -(background.contentSize.width)) {
            [_backgroundNode incrementOffset:ccp(background.contentSize.width*2,0) forChild:background];
        }
    }
}
- (void) dealloc
{
     _backgroundNode = nil;
    // _backgrounds = nil;
    [_backgrounds removeAllChildren]; 
    [_backgrounds release];
    [super dealloc];
}
@end

Answer 1

Well, here’s how I have gone about it:

• Get as close as possible to a POT texture size. 1920×640 costs you as much memory as a 2048×2048. Maybe you could get your artists to combine the three-five sprites on a single 2048×2848 png, crop with an plist (like for animation).
• Whenever possible, load textures ‘just in time’, ie before they are required to be visible. If load time became an issue (perceivable lag at an inappropriate game circumstance), convert the texture to .pvr format (faster load), later to .pvr.gz (still faster load time, smaller app download size). PVR will cause some artefacts, so check with graphic people on your project before comiting.
• Coming out of any level transition (either to some kind of menu or to some cut-scene), cleanup memory used by textures. This means that if the game logic requires returning to the main scene, reload textures just-in-time, during the transition.
• Last ditch, change the depth setting before loading these large textures (code snippet below). Setting to RGBA444 will save 75% of the memory requirement, BUT, you take a hit on some graphic quality, especially for high saturation images. Once again, if you need to go there, get your graphics people to optimize the images to this depth, so they are satisfied with the result on device.

cleanup:

NSLog(@"GESprite<removeUnusedSprites> : before purging all caches");
[[CCTextureCache sharedTextureCache] dumpCachedTextureInfo];
[[CCSpriteFrameCache sharedSpriteFrameCache] removeUnusedSpriteFrames];
[[CCDirector sharedDirector] purgeCachedData];
NSLog(@"GESprite<removeUnusedSprites> : after purging all caches");
[[CCTextureCache sharedTextureCache] dumpCachedTextureInfo];

depth (in a CCSprite derivative class, some utility methods), you can do this anywhere anytime:

+(void) mediumPixelFormat{
    [CCTexture2D setDefaultAlphaPixelFormat:kTexture2DPixelFormat_RGBA4444];
}

+(void) highPixelFormat{
    [CCTexture2D setDefaultAlphaPixelFormat:kTexture2DPixelFormat_RGBA8888];
}