Applying Zoom Effect In cocos2D gaming environment?

Question

I\'m working on a game with cocos2D game engine and make load all the sprites while it load the level, now as because some of sprites (obs

Answer 1

My code and it works better than other ones:

- (void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    NSArray* allTouches = [[event allTouches] allObjects];
    CCLayer *gameField = (CCLayer *)[self getChildByTag:TAG_GAMEFIELD];
    if (allTouches.count == 2) {

        UIView *v = [[CCDirector sharedDirector] view];
        UITouch *tOne = [allTouches objectAtIndex:0];
        UITouch *tTwo = [allTouches objectAtIndex:1];
        CGPoint firstTouch = [tOne locationInView:v];
        CGPoint secondTouch = [tTwo locationInView:v];
        CGPoint oldFirstTouch = [tOne previousLocationInView:v];
        CGPoint oldSecondTouch = [tTwo previousLocationInView:v];
        float oldPinchDistance = ccpDistance(oldFirstTouch, oldSecondTouch);
        float newPinchDistance = ccpDistance(firstTouch, secondTouch);

        float distanceDelta = newPinchDistance - oldPinchDistance;
        NSLog(@"%f", distanceDelta);
        CGPoint pinchCenter = ccpMidpoint(firstTouch, secondTouch);
        pinchCenter = [gameField convertToNodeSpace:pinchCenter];

        gameField.scale = gameField.scale - distanceDelta / 100;
        if (gameField.scale < 0) {

            gameField.scale = 0;
        }
    }
}