UIView cut hole

UIViewCutHole.m

- (void)cutHole {
    CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
    
    CGMutablePathRef path = CGPathCreateMutable();
    CGFloat radius = self.holeView.frame.size.height / 2;
    CGFloat x = self.holeView.frame.size.width / 2;
    CGFloat y = self.holeView.frame.size.height / 2;
    
    CGPathAddArc(path, nil, x, y, radius, 0.0, 2 * 3.14, false);
    CGPathAddRect(path, nil, CGRectMake(0, 0, self.holeView.frame.size.width, self.holeView.frame.size.height));
    
    maskLayer.path = path;
    maskLayer.fillRule = kCAFillRuleEvenOdd;
    
    self.holeView.layer.mask = maskLayer;
    self.holeView.clipsToBounds = YES;
    
    CGPathRelease(path);
}