Question

I have an array called spriteArray:

@property (retain) NSMutableArray *spriteArray;
@synthesize spriteArray = spriteArray_;

And I have a sprite:

@property (nonatomic, assign) CCSprite *sprite;
@synthesize sprite = sprite_;

I create a certain number of sprites depending on the value of spriteNumber (an integer):

for (int i = 0; i < spriteNumber; i++) {
    if ([spritetype_ isEqualToString:@"typeOne"]) {

        self.sprite = [[typeOne alloc] initTypeOne];
        self.sprite.position = randomPoint;
        [self.spriteArray addObject:self.sprite];
        [self addChild:self.sprite];
    }}

The sprites initialise successfully, and appear on the screen as they should. However, when I try to use them for collision detection, only one of them works:

    if (CGRectIntersectsRect(self.sprite.boundingBox, self.swat.boundingBox)) {
    //swat is another sprite
    NSLog(@"detected");
    }

What I wanted is to ‘index’ each of the sprites as they are being created, so that the collision detection works.

SAMPLE CODE: http://pastebin.com/swNUwB6U

Answer 1

Use the tag property for the sprite.

for (int i = 0; i < spriteNumber; i++) {
  if ([spritetype_ isEqualToString:@"typeOne"]) {

    typeOne *typeOneSprite = [[typeOne alloc] initTypeOne];
    typeOneSprite.position = randomPoint;

// USE TAG!
    typeOneSprite.tag = i;

    [self.spriteArray addObject:typeOneSprite];
    [self addChild:typeOneSprite];
// Don't forget to release if you are not using ARC.
}}

Then call the tag value in the collision detection code.

[self.spriteArray enumerateObjectsUsingBlock:^(id obj, NSUInteger index, BOOL *stop)
 {
    typeOne *spriteOne = (typeOne *)obj;
    if (CGRectIntersectsRect(spriteOne.boundingBox, self.swat.boundingBox)) 
    {
      //swat is another sprite
      if (spriteOne.tag == numberyouwant){}
      NSLog(@"detected");
     }
 }];