create particles without opengl and cocos2D. snowfall application

Question

well I wanted to create particles like (snow ) without openGL or cocs2D, and I found this sample code called snowfall and in this code there is this :

flakeImage = [UIImage imageNamed:@"flake.png"];

// start a timet that will fire 20 times per second
[NSTimer scheduledTimerWithTimeInterval:(0.5) target:self selector:@selector(onTimer) userInfo:nil repeats:YES];
}



// Timer event is called whenever the timer fires

- (void)onTimer
{


// build a view from our flake image
UIImageView* flakeView = [[UIImageView alloc] initWithImage:flakeImage];

// use the random() function to randomize up our flake attributes
int startX = round(random() % 320);
int endX = round(random() % 320);
double scale = 1 / round(random() % 100) + 1.0;
double speed = 1 / round(random() % 100) + 1.0;

// set the flake start position
flakeView.frame = CGRectMake(startX, -100.0, 5.0 * scale, 5.0 * scale);
flakeView.alpha = 0.25;

// put the flake in our main view
[self.view addSubview:flakeView];

[UIView beginAnimations:nil context:flakeView];
// set up how fast the flake will fall
[UIView setAnimationDuration:5 * speed];

// set the postion where flake will move to
flakeView.frame = CGRectMake(endX, 500.0, 5.0 * scale, 5.0 * scale);

// set a stop callback so we can cleanup the flake when it reaches the
// end of its animation
[UIView setAnimationDidStopSelector:@selector(onAnimationComplete:finished:context:)];
[UIView setAnimationDelegate:self];
[UIView commitAnimations];  }
- (void)onAnimationComplete:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context {

UIImageView *flakeView = context;
[flakeView removeFromSuperview];
// open the debug log and you will see that all flakes have a retain count 
// of 1 at this point so we know the release below will keep our memory 
// usage in check
NSLog([NSString stringWithFormat:@"[flakeView retainCount] = %d", [flakeView retainCount]]);
[flakeView release];


}

I wanted to know if this code can hurt performance or memory ( maybe because it use a timer)?And if it is not a good idea I heard about CAReplicator that we can use for iphone but the CAReplicatorDemo only work for mac on the apple documentation :/ sorry for my english I'm french :/

Answer 1

You can try my KHParticleView, it use cocos2d particle and add cocos2d view on the top. Check the code here: https://github.com/lephukhanhhuy/KHParticleView

Answer 2

You can use a CAEmitterLayer to do particle effects on iOS 5. I've used it for flames and smoke before but it should work just fine for snow.

Answer 3

Sure, it will affect performance. You will not see it in Simulator though. UIImageView is too heavy to be created 20 times a second. You may try to use a pool of CALayer-s instead (and CAAnimation).