Unity3D screen metrics utility for 2D camera use

ScreenMetrics2D.cs

using UnityEngine;

// @kurtdekker
//
// Ultra simple script to give you the "live edges" of your screen.
// This updates for any screen orientation, dimensions or camera.
//
// Presumes:
//	- orthographic Camera pointed +Z
//	- returns values in the Z == 0 plane.
//
// To use: NEVER PLACE THIS IN YOUR SCENE!!! DO NOT DRAG IN!!!
//
// Simply access it with these static Vector3 properties:
//		- ScreenMetrics2D.LowerLeft
//		- ScreenMetrics2D.UpperRight
//
// There are also TopEdge, LeftEdge, RightEdge and BottomEdge properties
//
// If it offends you that this runs every frame, by all
// means feel free to cache this data and only run the
// MyUpdate when some input property changes. :)
//
// Enjoy!

public class ScreenMetrics2D : MonoBehaviour
{
	public static Vector3 LowerLeft
	{
		get
		{
			if (!_I) I.ToString();
			return _LowerLeft;
		}
	}

	public static Vector3 UpperRight
	{
		get
		{
			if (!_I) I.ToString();
			return _UpperRight;
		}
	}

	// these are a bunch of quality of life improvers.
	public static float TopEdge { get { return UpperRight.y; }}
	public static float BottomEdge { get { return LowerLeft.y; }}
	public static float LeftEdge { get { return LowerLeft.x; }}
	public static float RightEdge { get { return UpperRight.x; }}

	//--------------------------------------------------------------
	// all business logic below... not necessary to use this script

	// cached state
	static Vector3 _LowerLeft;
	static Vector3 _UpperRight;
	static ScreenMetrics2D _I;

	static ScreenMetrics2D I
	{
		get
		{
			if (!_I)
			{
				var go = new GameObject( "ScreenMetrics.Instance.");

				_I = go.AddComponent<ScreenMetrics2D>();

				_I.MyUpdate();
			}
			return _I;
		}
	}

	Camera targetCamera;

	void MyUpdate()
	{
		if (!targetCamera)
		{
			targetCamera = Camera.main;
		}

		{
			Vector3 position = targetCamera.ViewportToWorldPoint( new Vector2( 0, 0));

			position.z = 0;

			_LowerLeft = position;
		}

		{
			Vector3 position = targetCamera.ViewportToWorldPoint( new Vector2( 1, 1));

			position.z = 0;

			_UpperRight = position;
		}
	}

	void Update()
	{
		MyUpdate();
	}
}

ScreenMetrics2DTester.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

// @kurtdekker - demonstrates the ScreenMetrics2D class

public class ScreenMetrics2DTester : MonoBehaviour
{
	GameObject LowerLeftMarker;
	GameObject UpperRightMarker;

	void Start()
	{
		// make some stuff to see in the corners
		LowerLeftMarker = GameObject.CreatePrimitive( PrimitiveType.Capsule);
		UpperRightMarker = GameObject.CreatePrimitive( PrimitiveType.Cube);
	}

	void Update ()
	{
		LowerLeftMarker.transform.position = ScreenMetrics2D.LowerLeft;
		UpperRightMarker.transform.position = ScreenMetrics2D.UpperRight;
	}
}