Overlapping canvas issue

Hi there.

I almost completed my own inventory script. But the overlapping check for the item canvas is driving me crazy. I can't figure out how to check it properly.

The problem: with bigger item sizes, there is an invisible seam at the top of each canvas item that triggers the overlapping check. I checked the child elements of the canvas objects, they are all in place and the right size. The calculation must be the problem.

That's the code I use:

Code (CSharp):

1. void CheckPlace()
2.     {
3.         if (!Blocked)
4.         {
5.             RectTransform ThisCanvasRect = ItemCanvas.GetComponent<RectTransform>();
6.  
7.             foreach (Transform OtherCanvas in ItemCanvas.transform.parent)
8.             {
9.                 if (OtherCanvas.tag == "ItemCanvas" && OtherCanvas.gameObject != ItemCanvas)
10.                 {
11.                     RectTransform OtherCanvasRect = OtherCanvas.GetComponent<RectTransform>();
12.  
13.                     if (CanvasOverlapping(ThisCanvasRect, OtherCanvasRect))
14.                     {
15.                         Blocked = true;
16.  
17.                         DLF("position blocked by " + OtherCanvas.name);
18.  
19.                         break;
20.                     }
21.                 }
22.             }
23.         }
24.     }
25.  
26.     bool CanvasOverlapping(RectTransform ThisCanvas, RectTransform OtherCanvas)
27.     {
28.         Rect TC = new Rect(ThisCanvas.localPosition.x, ThisCanvas.localPosition.y, ThisCanvas.rect.width, ThisCanvas.rect.height);
29.         Rect OC = new Rect(OtherCanvas.localPosition.x, OtherCanvas.localPosition.y, OtherCanvas.rect.width, OtherCanvas.rect.height);
30.  
31.         //Rect TC = new Rect(ThisCanvas.rect.xMin, ThisCanvas.rect.yMin, ThisCanvas.rect.xMax, ThisCanvas.rect.yMax);
32.         //Rect OC = new Rect(OtherCanvas.rect.xMin, OtherCanvas.rect.yMin, OtherCanvas.rect.xMax, OtherCanvas.rect.yMax);
33.  
34.         return TC.Overlaps(OC);
35.     }

As you can see in the following picture (the backpack will block the belt):

• an 1x1 item is not blocking at all
  
  
• an 2x2 item works properly
  
  
• an 3x3 item will block an additional row (but just above)
  
  
• an 4x4 item will block two additional rows (again, just above)
  
  
• and an 5x5 item will block three additional rows...

How do I use the check correctly?