Performance scrolling and retina resolution images in CALayer

I have a UIView that is placed as a subview in a UIScrollView. I have several child views made up of images, text, and buttons in the UIView. In order to get decent scrolling performance I set shouldRasterize = YES on the layer in the UIView. This worked great in that performance increased so I have smooth scrolling and doesn't pose an issue since my graphics are static once drawn. However, the开发者_如何学运维 problem is that when I set shouldRasterize that the rasterized graphics are blurry and low resolution on a Retina display. Is there a way to have high resolution graphics that are rasterized for performance?

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Seems I needed to set rasterizationScale to the proper value for the device as follows.

myView.layer.rasterizationScale = [[UIScreen mainScreen] scale];

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I had a similar problem-- a rotated UIView with several UIImageView subviews. When I set the rasterizationScale = 2.0, the images became crisper, but this caused serration to reemerge. To fix this, I created a containerView that held the UIView and UIIMageViews (which were previously subviews of the UIView) and applied rasterizationScale = 1.0 to the UIView and rasterizationScale = 2.0 to the UIImageViews. Now everything looks quite nice.

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@Jamie Hamick's answer in Swift 5:

myView.layer.rasterizationScale = UIScreen.main.scale