[Unity]テキストのRect情報取得

TestGUI.cs

using UnityEngine;
using System.Collections;

public class TestGUI : MonoBehaviour {

	private string txt = "test";
	public GUIText guiText;
	public GUIText guiTextInfo;
	public GUITexture guiTextureBg;
	
	void OnGUI () {
		txt = GUI.TextField(new Rect(5, 5, 200, 20), txt);
		guiText.text = txt;
		guiTextInfo.text = guiText.GetScreenRect().ToString();
		Rect rcGuiText = guiText.GetScreenRect();
		Rect rc = rcGuiText;
		rc.x += -Screen.width*.5f;
		rc.y -= Screen.height*.5f;
		guiTextureBg.pixelInset = rc;
	}
}