Masking views: http://www.objectivetidbits.com/2015/02/28/masking-views/

cornerRadius.m

view.layer.cornerRadius = 8.0

imageViewMask.m

imageView.layer.mask = starShape;

maskLayer.m

CAShapeLayer *maskLayer = [CAShapeLayer new];
maskLayer.frame = self.titleLabel.bounds;

maskLayerAndPath.m

maskLayer.path = maskPath.CGPath;

maskPath.m

UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:self.titleLabel.bounds
                                               byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight
                                                     cornerRadii:CGSizeMake(8.0, 8.0)];

Star.pcvd

starLayer.m

CAShapeLayer *starShape = [CAShapeLayer new];
starShape.frame = imageView.bounds;
    
starShape.path = starPath.CGPath;

starPath.m

UIBezierPath* starPath = UIBezierPath.bezierPath;

[starPath moveToPoint: CGPointMake(128, 0)];
[starPath addLineToPoint: CGPointMake(156.58, 88.66)];
[starPath addLineToPoint: CGPointMake(249.74, 88.45)];
[starPath addLineToPoint: CGPointMake(174.24, 143.03)];
[starPath addLineToPoint: CGPointMake(203.24, 231.55)];
[starPath addLineToPoint: CGPointMake(128, 176.62)];
[starPath addLineToPoint: CGPointMake(52.76, 231.55)];
[starPath addLineToPoint: CGPointMake(81.76, 143.03)];
[starPath addLineToPoint: CGPointMake(6.26, 88.45)];
[starPath addLineToPoint: CGPointMake(99.42, 88.66)];
[starPath closePath];

viewMask.m

self.view.layer.mask = maskLayer;