How to change the rectangle of an object moving using a bezier path in the lens c

Question

I want to change the rectangle with the movement of the bezier path:

CAShapeLayer *shapeLayer = [CAShapeLayer layer]; shapeLayer.path = [self createArcPath].CGPath; shapeLayer.strokeColor = [[UIColor blueColor] CGColor]; shapeLayer.lineWidth = 1.0; shapeLayer.fillColor = [[UIColor clearColor] CGColor]; [self.view.layer addSublayer:shapeLayer]; UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom]; // btn.frame = CGRectMake(326, 174, 64, 64); [btn setBackgroundImage:[UIImage imageNamed:@"Volleyball_Ball.png" forState:UIControlStateNormal]; [self.view addSubview:btn]; // car = [CALayer layer]; // car.frame = CGRectMake(326, 174, 48, 48); // car.contents = (id)([UIImage imageNamed:@"1453303583_circle_blue.png"].CGImage); // [self.view.layer addSublayer:car]; CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:@"position"]; anim.path = [self createArcPath].CGPath; anim.rotationMode = kCAAnimationRotateAuto; anim.delegate = self; anim.repeatCount = 1; anim.duration = 3.0; [btn.layer addAnimation:anim forKey:@"race"]; btn.frame = CGRectMake(20, 174, 64, 64); 

I would like to get CGRECT for each point while moving and storing and array, it is already moving in a circle, but I need to get CGRECT for each point.