У меня есть приложение, где у меня естьUIImageView который отображает основное изображение и другоеUIImageView будучи использован в качестве маски, которая показывает круг, который является прозрачным и за пределами его непрозрачного, этот круг может быть перемещен с помощьюUIPanGestureRecognizerЯ хочу знать выход, чтобы обрезать изображение внутри круга в новое изображение. Вот прикрепленный код и снимок экрана

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    // create pan gesture

    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self
                                                                          action:@selector(handlePan:)];
    [self.view addGestureRecognizer:pan];


    CAShapeLayer *shapeLayer = [CAShapeLayer layer];
    shapeLayer.path = [[self makeCircleAtLocation:self.view.center radius:100.0] CGPath];
    shapeLayer.strokeColor = [[UIColor clearColor] CGColor];
    shapeLayer.fillColor = nil;
    shapeLayer.lineWidth = 3.0;

    // Add CAShapeLayer to our view

    [self.view.layer addSublayer:shapeLayer];

    // Save this shape layer in a class property for future reference,
    // namely so we can remove it later if we tap elsewhere on the screen.

    self.circleLayer = shapeLayer;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
// Create a UIBezierPath which is a circle at a certain location of a certain radius.
// This also saves the circle's center and radius to class properties for future reference.

- (UIBezierPath *)makeCircleAtLocation:(CGPoint)location radius:(CGFloat)radius
{
    self.circleCenter = location;
    self.circleRadius = radius;

    UIBezierPath *path = [UIBezierPath bezierPath];
    [path addArcWithCenter:self.circleCenter
                    radius:self.circleRadius
                startAngle:0.0
                  endAngle:M_PI * 2.0
                 clockwise:YES];

    return path;
}

- (void)handlePan:(UIPanGestureRecognizer *)gesture
{
    static CGPoint oldCenter;

    if (gesture.state == UIGestureRecognizerStateBegan)
    {
        // If we're starting a pan, make sure we're inside the circle.
        // So, calculate the distance between the circle's center and
        // the gesture start location and we'll compare that to the
        // radius of the circle.

        CGPoint location = [gesture locationInView:gesture.view];
        CGPoint translation = [gesture translationInView:gesture.view];
        location.x -= translation.x;
        location.y -= translation.y;

        CGFloat x = location.x - self.circleCenter.x;
        CGFloat y = location.y - self.circleCenter.y;
        CGFloat distance = sqrtf(x*x + y*y);

        // If we're outside the circle, cancel the gesture.
        // If we're inside it, keep track of where the circle was.


        oldCenter = self.circleCenter;
    }
    else if (gesture.state == UIGestureRecognizerStateChanged)
    {
        // Let's calculate the new center of the circle by adding the
        // the translationInView to the old circle center.

        CGPoint translation = [gesture translationInView:gesture.view];
        CGPoint newCenter = CGPointMake(oldCenter.x + translation.x, oldCenter.y + translation.y);

      //  CGPoint newCenter = [gesture locationInView:self.view];
        if (newCenter.x < 160) {
            newCenter.x = 160;
        }
        else if (newCenter.x > self.view.frame.size.width - 160) {
            newCenter.x = self.view.frame.size.width - 160;
        }
        if (newCenter.y < 242) {
            newCenter.y = 242;
        }
        else if (newCenter.y > self.view.frame.size.height - imageMain.center.y) {
            newCenter.y = self.view.frame.size.height - imageMain.center.y;
        }

        // Update the path for our CAShapeLayer

       // self.circleLayer.path = [[self makeCircleAtLocation:newCenter radius:self.circleRadius] CGPath];
        imageCircle.center = newCenter;

    }
}

@end

И результат