Is there a way to detect a retina display?

Archived Forums Questions & Answers
1

There are circumstances where it's nice to know if you are running on a retina display or not.

For example, GUI code that distinguishes between taps and drags. There is typically a threshold, and if the touch moves beyond that threshold, the touch turns into a drag. If the threshold is too small, then it becomes difficult to tap the object- the slightest move turns into a drag. Too high and the start of the drag is delayed and feels abrupt.

Is there a clean way to determine this in Unity?

6 Answers

6
6

Since Unity 3.5, Screen has a property dpi that you can use for this purpose:

Screen.dpi

This works on Android and iOS. iPhone Retina displays have 320 ppi, iPad 3 has 260 ppi. dpi = ppi, ppi (pixels per inch) is Apple-speak, dpi (dots per inch) is Android speak. IMHO, ppi makes a little more sense because on screens we have pixels and not dots as in print :wink:

This is a much safer approach than asking for specific devices.

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7

here is little plugin I wrote for iOS screen scale detection

DeviceDisplay.scaleFactor returns int value from 1 to 3 according do device screen scale factor

public class UIScale : MonoBehaviour {

	
	
	void Start () {
		Debug.Log(DeviceDisplay.scaleFactor);
	}
}

Don't know if it's from you, but it's working perfectly, thanks a lot! :)

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3

You could use: 

if (iPhoneSettings.generation == iPhoneGeneration.iPhone4) {
//then device uses retina display
}

I assume this class will get updated as new devices get released. If, for any reason, a future device had multiple resolutions, you could use this with Screen.currentResolution, iPhoneSettings.model, and/or the hardware specs to try to pin down the pixel density.

http://unity3d.com/support/documentation/ScriptReference/iPhoneSettings.html

This is a useful tip, but again, code written this way would fail on future devices.

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I know this is an old question, but I think you are looking at it backwards Bampf. Program for the devices you have now... Assume future devices will work like the Retina does (I can't see Apple jamming more ppi anytime soon.) You'll likely need to do App updates when new hardware arrives anyway. So instead of looking for iPhone4, look for the low-res devices (which there will likely never be more of.) If it's not an old device, than it's likely a Retina device (at least in the forseeable future.)

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2

Try screen.currentResolution. The iPhone 4 will have a much higher one than the normal iPhone.

True, but that's not quite what I want. It could easily fail when Apple comes out with a future device. The ideal solution would be based on the pixel density (or a property that Apple exposes), not the resolution.

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Resolution do not solve what we want, another reason for not using resolution is because we can have devices with the same display size and really different resolutions.

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4

It’s a hack, but i just get the worldtoscreen coordinates of the bounds of a known box collider, and just use the values (which will vary based on pixel density) as a variable.

5

check for the resolution using screen.currentResolution and with tht value u can detect whether it is normal or retina display