"Empty" (Checkerboard) iOS Background Pattern

checkerboard.mm

UIImage *EmptyBGPattern()
{
    CGFloat side = 16;
    CGSize size = CGSizeMake(side, side);
    UIGraphicsBeginImageContextWithOptions(size, NO, [UIScreen mainScreen].scale);
    
    [[UIColor whiteColor] setFill];
    UIRectFill((CGRect){.size = size});
    
    CGRect r = CGRectMake(0, 0, side / 2, side / 2);
    [[UIColor colorWithWhite:0.8f alpha:1] setFill];
    UIRectFill(r);
    r.origin = CGPointMake(side / 2, side / 2);
    UIRectFill(r);

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}