Retina alterative to CGRectIntegral

CGRectIntegral is a function for rounding all the values of a CGRect at once, typically used for snapping frames to pixels. For a good example of how this helps prevent image blurring and other related rendering issues see this stackoverflow answer.

On retina screens CGRectIntegral still rounds to the nearest point (1.0) rather than the nearest pixel (0.5) which isn’t ideal.

My solution to this is implemented as a UIView category which matches my use case for CGRectIntegral 100% of the time. Your mileage may vary.

//UIView Category
- (CGRect) roundedFrame {
    return CGRectMake(
          round(self.frame.origin.x * [[UIScreen mainScreen] scale]) / [[UIScreen mainScreen] scale],
          round(self.frame.origin.y * [[UIScreen mainScreen] scale]) / [[UIScreen mainScreen] scale],
          round(self.frame.size.width * [[UIScreen mainScreen] scale]) / [[UIScreen mainScreen] scale],
          round(self.frame.size.height * [[UIScreen mainScreen] scale]) / [[UIScreen mainScreen] scale]
      );
}

//Usage
view.frame = [view roundedFrame];