Use a pool to spawn images - iphone

Question

Hi every one here is my code:
-(void) createNewImage {
[imageView setCenter:[self randomPointSquare]];
[[self view] addSubview:imageView];
[views addObject:imageView];
[imageView release];
ix=imageView.center.x;
iy=imageView.center.y;
[XArray addObject:[NSNumber numberWithFloat:(240 - ix)/diviseurVitesse]];
[YArray addObject:[NSNumber numberWithFloat:(160 - iy)/diviseurVitesse]];
}
-(void)moveTheImage{
for (NSUInteger i = 0; i < [views count]; i++) {
imageView = [views objectAtIndex:i];
X = [[XArray objectAtIndex:i] floatValue];
Y = [[YArray objectAtIndex:i] floatValue];
imageView.center=CGPointMake(imageView.center.x + X, imageView.center.y + Y);
}
With this code, image are created and move to the center of the screen but after some seconds the performance decrease and come to 30fps. I would like to keep fps at 60 but I don't know how to proceed.Some people say that I can use pool but it's hard for me to use it because I don't really know how to use it :/ sorry for my english I'm french :/

Answer 1

Your problem is most likely here - [views addObject:imageView];. Adding object to a persistent dataset like NSMutableArray retains the object, so memory consumption actually grows. Try manipulating your images in [self.view subviews] without storing them in array.
EDIT: Your code should look something like this
- (void)createAndMove {
UIImageView *imageView = [UIImageView alloc] initWithImage:image];
[imageView setCenter:[self randomPointSquare]];
[self.view addSubview:imageView];
[UIView animateWithDuration:5 animations:^{
imageView.center = self.view.center;
}];
}
EDIT 2:
- (void)moveImages {
for (UIImageView *img in [self.view subviews]) {
[UIView animateWithDuration:5 animations:^{
img.center = self.view.center;
}];
}
}

Answer 2

What happens when your object reaches the centre of the screen? If it just sits there and the other images overlap it, then you could then reset it to be at the start position rather than creating a new image. If you are moving them to the centre and then leaving them there, pretty soon you will have many many views and that will just kill the performance.
So, imagine you have 3 views. View 1 is created and appears at edge of screen and moves towards centre. When that is half-way to the centre, view 2 is created and appears at the edge of the screen and starts to move towards the centre. When view 2 is half-way to the centre, view 1 is at the centre and view 3 is created and appears at the edge of the screen. Now, when view 2 reaches the centre, view 1 is reset to be at the edge of the screen (it will be covered by view 2 so it won't be noticed). Then when view 3 reaches the centre, it will cover view 2, so that can be reset to the edge of the screen.
Hope this makes sense - it's a bit difficult without drawing pictures or knowing exactly what you are moving around on the screen, etc.