Using GUI in subframes ie Cameras with normalized View ports

I have mulitple Cameras displaying at the same time using Normalized view port rects. I know that eventually I will want to let users resize these rects and currently want it to work on mulitple resolutions.

The problem is that camera rects (camera.rect and Camera.pixelRect) are flipped vertically to GUI co-ordinates.

The solution
A) calculate window height using camera.rect and camera.pixelRect

B)calculate carmera pixelRect in GUI oriented co-ordinates

C)use these co-ordinates to position GUI elements inside the camera subframe.

This is all do-able without much code (10? lines) usually when do something like this someone points out to me later I could have used an existing unity function to it in 1 line of code.

So does anyone know a direct way to get a) or B)?

If not I will write my code and post to Wiki

Cheers,
Grant

 

Here is the script I attach to a camaera that holds a Rect with the cameras pixels in GUI co-ordinate space.

Code (csharp):

1. import UnityEngine
2.  
3. class GUICam (MonoBehaviour):
4.  
5.     public GUIRect as Rect
6.     cam as Camera
7.    
8.     def Start():
9.         cam = transform.camera
10.  
11.     def Update ():
12.         pr=cam.pixelRect
13.         r = cam.rect
14.         screenHeight = pr.height / r.height
15.         GUIRect = Rect(pr.left,screenHeight-(pr.top+pr.height),pr.width,pr.height)
16.        
17.  

to use I put this on GUI generation script which is a camera component and draw button in the top left of the camera viewport.

Code (csharp):

1.  
2.     aGUICam as GUICam
3.  
4.     def Start ():
5.         aGUICam = transform.camera.GetComponent(GUICam)
6.  
7.     def ButtonGUI():
8.         r=aGUICam.GUIRect
9.         GUI.Button ( Rect (r.xMin+10,r.yMin+50,50, 30), "button"))     

http://www.unifycommunity.com/wiki/index.php?title=GUICam