iPhone 6+ screen dimension confusion

Question

When printing the screen height of the iPhone 6+ simulator I get 2208, as expected. However when I test on an actual iPhone 6+ I get 1920. Very confused about which one is right. Here is the code I'm using:

func test() {
    if UIDevice().userInterfaceIdiom == .phone {
        switch UIScreen.main.nativeBounds.height {
        case 1136:
            print("iPhone 5 or 5S or 5C")
        case 1334:
            print("iPhone 6/6S/7/8")
        case 2208:
            print("iPhone 6+/6S+/7+/8+")
        case 2436:
            print("iPhone X")
        default:
            print("unknown")
        }
    }
}

See https://stackoverflow.com/questions/25755443/iphone-6-plus-resolution-confusion-xcode-or-apples-website-for-development — rmaddy, Jan 18 '18 at 06:48

score 1 · Accepted Answer · answered Jan 18 '18 at 06:45

1

The problem is that all plus devices they do a downsampling so to fix this issue you need to test two different resolutions, one for the simulator 2208 and one for the real devices 1920 as you can see in this answer:

case 1920, 2208:

answered Jan 18 '18 at 06:45

Leo Dabus

229,809
59
489
571

So, in deployment, all plus size iPhones will use the 1920 height? The 2208 figure is only for plus simulators? What's the point of that? – goat Jan 18 '18 at 07:42
This is just how it works. 2208 is the render size and 1920 is the actual number of physical pixels. So in the simulator it just displays it at render size but in the real device it needs downsample the image to be able to display it. – Leo Dabus Jan 18 '18 at 13:49

Jaydeep Vora · Answer 2 · 2018-01-18T06:50:08.683

0

Videos, OpenGL, and other things based on CALayers that deal with pixels will deal with the real 1920x1080 frame buffer on device (or 2208x1242 on sim). Things dealing with points in UIKit will be deal with the 2208x1242 (x3) bounds and get scaled as appropriate on device.

The simulator does not have access to the same hardware that is doing the scaling on device and there's not really much of a benefit to simulating it in software as they'd produce different results than the hardware. Thus it makes sense to set the nativeBounds of a simulated device's main screen to the bounds of the physical device's main screen.

iOS 8 added API to UIScreen (nativeScale and nativeBounds) to let a developer determine the resolution of the CADisplay corresponding to the UIScreen.

edited Jan 18 '18 at 06:50

answered Jan 18 '18 at 06:34

Jaydeep Vora

6,085
1
22
40

Right. `bounds`: "measured in points", `nativeBounds `: "measured in pixels" – bauerMusic Jan 18 '18 at 06:37
This doesn't explain why the OP is getting 2208 on an iPhone 6+ simulator but 1920 on a real iPhone 6+. – rmaddy Jan 18 '18 at 06:44
UIKit and points will not be 2208x1242. That's the physical resolution. Divide by the scale to get points. – rmaddy Jan 18 '18 at 06:52

iPhone 6+ screen dimension confusion

2 Answers2