Clamping a ui image to a mask region

Hey friends,

Working on a problem that involves dragging a UI image around a masked screen area. I'd like to limit the ability of a user to drag the image past the mask so the top of the image will never be below the top of the mask. This would be true for the bottom, left and right sides of the mask as well.

Hoping these demonstrate what I intend to accomplish:

Clamping to the top:

Clamping to the right:



Any thoughts on how I might go about this?

 

Solved it!

For anyone who is interesting here's the code.

PhotoMinWidth is the mask Rect Transform.

Code (CSharp):

1.     public void ClampScaleX(){
2.  
3.         photoRect.localScale = new Vector3 (PhotoMinWidth.sizeDelta.x / photoRect.sizeDelta.x, PhotoMinWidth.sizeDelta.x / photoRect.sizeDelta.x, PhotoMinWidth.sizeDelta.x / photoRect.sizeDelta.x);
4.    
5.     }
6.  
7.     public void ClampScaleY(){
8.  
9.         photoRect.localScale = new Vector3 (PhotoMinWidth.sizeDelta.y / photoRect.sizeDelta.y, PhotoMinWidth.sizeDelta.y / photoRect.sizeDelta.y, PhotoMinWidth.sizeDelta.y / photoRect.sizeDelta.y);
10.  
11.     }
12.  
13.     public void ClampRight(){
14.  
15.         float picClampPosRight = ((photoRect.sizeDelta.x * photoRect.localScale.x) - PhotoMinWidth.sizeDelta.x)/2f;
16.         photoRect.anchoredPosition = new Vector2 (-picClampPosRight, photoRect.anchoredPosition.y);
17.    
18.     }
19.  
20.     public void ClampLeft(){
21.  
22.         float picClampPosLeft = ((photoRect.sizeDelta.x * photoRect.localScale.x) - PhotoMinWidth.sizeDelta.x)/2f;
23.         photoRect.anchoredPosition = new Vector2 (picClampPosLeft, photoRect.anchoredPosition.y);
24.  
25.     }
26.  
27.     public void ClampTop(){
28.  
29.         float picClampPosTop = ((photoRect.sizeDelta.y * photoRect.localScale.y) - PhotoMinWidth.sizeDelta.y)/2f;
30.         photoRect.anchoredPosition = new Vector2 (photoRect.anchoredPosition.x, - picClampPosTop);
31.  
32.     }
33.  
34.     public void ClampBottom(){
35.  
36.         float picClampPosBtm = ((photoRect.sizeDelta.y * photoRect.localScale.y) - PhotoMinWidth.sizeDelta.y)/2f;
37.         photoRect.anchoredPosition = new Vector2 (photoRect.anchoredPosition.x, picClampPosBtm);
38.  
39.     }