Implementing smooth loader in a cocos2d-iphone app - ios

Question

I want to implement startup loader in my app. It should be like this: after startup splash screen, user will watch simple animataion and in meanwhile app preload sound effects, background music, sprite images, spritesheets and so on. Current implementation:
- (id)init {
if((self = [super init])) {
// Some other setup ...
CGRect rect;
rect = waveSprite.textureRect;
waveInitialTexRectOrigin = rect.origin;
rect.size.width = 91;
waveSprite.textureRect = rect;
assetFilenames = [[NSArray alloc] initWithObjects:
// images
#"background.png",
// spritesheets
#"sprites.plist",
// fonts
#"main.png",
// sound effects
#"button.wav",
nil];
assetCounter = 0;
[self loadAsset];
}
return self;
}
- (void)update:(ccTime)dt {
CGRect rect;
rect = waveSprite.textureRect;
rect.origin.x += dt*kLoaderWaveSpeed;
while (rect.origin.x > waveInitialTexRectOrigin.x + kLoaderWavePeriod) {
rect.origin.x -= kLoaderWavePeriod;
}
waveSprite.textureRect = rect;
}
#pragma mark Private
- (void)loadAsset {
// CCLOG(#"loadAsset");
NSString *filename = [assetFilenames objectAtIndex:assetCounter];
CCLOG(#"loading %#", filename);
NSString *ext = [filename pathExtension];
if ([ext doesMatchRegStringExp:#"[png|jpg]"]) {
[[CCTextureCache sharedTextureCache] addImage:filename];
} else if ([ext isEqualToString:#"plist"]) {
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:filename];
} else if ([ext doesMatchRegStringExp:#"[caf|wav|mp3]"]) {
[[SimpleAudioEngine sharedEngine] preloadEffect:filename];
}
assetCounter++;
if (assetCounter < [assetFilenames count]) {
[self performSelector:#selector(loadAsset) withObject:self afterDelay:0.1f];
} else {
[self performSelector:#selector(loadingComplete) withObject:self afterDelay:0.2];
}
But the animation is SO abrupt.
UPD I've already tried
[self performSelectorInBackground: withObject:]
but it didn't seem to work (hung on loading first asset). Maybe I should try better in this direction.
UPD2 Smooth = not abrupt, without delays and flicker. fps doesn't matter, 20 fps quite OK

Answer 1

I'm not experienced with CC2D, but here's what I used in my ViewController to show a smooth animated loading indicator:
//Set up and run your loading scene/indicator here
dispatch_async( dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
//Load your scene
dispatch_async( dispatch_get_main_queue(), ^{
//This fires when the loading is complete
//Show menu and destroy the loader scene/indicator here
});
});
I guess it's worth a try.

Answer 2

You should not be using performSelectorInBackground anymore, it is not deprecated but it might be soon, with GCD now in the picture.
What I would try is run the animation in the main thread since it is the only one that can do UI updates. And spawn one or more threads using GCD to load all your assets.
I would use concurrent dispatch queues to load everything in parallel and simply dismiss the animation when this is done.
You can get complete information about concurrent dispatch queues here:
Concurrency Programming Guide
Hope that helps.

Answer 3

That is because you are doing everything on the same thread. Use a separate thread for the loader.
Hope this helps.
Cheers!
EDIT : Take a look at this.