BOOK: Get closest scene objects

I'm throwing this question out to John K specifically because I'm borrowing some code from his TX book, but any insight is much appreciated.

To start, some background: I'm using an inventory management system as described in the TX book except I don't want the player to pick up items when the two collide. Instead I want the player to have to press a button (the X button on the gamepad in this case) when within range of the item. My game has limited inventory slots so I want the player to be able to make decisions about what they are picking up and when.

To this end I've created a PickUpDetectorComponent that allows me to set the range, display a "you can now pick something up" graphic when the player is in range, and do the actual pick up. This is where things get a hairy.

In the PickupDetectorComponent's ProcessTick method I'm running code very similar to the GetClosestEnemy code in TXBook (p. 198). This allows me to see if any pickups are in range and display my "pick up graphic". So that's good. Now, if the player presses the X button this code block is run:

float closest = _range;
T2DSceneObject closestPickup = null;

foreach (T2DSceneObject pickup in listPickups)
{
   float distance = Vector2.Distance(SceneObject.Position,  
                                     pickup.Position);
                
   if (distance < closest)
   {
      closestPickup = pickup;
   }
}

return closestPickup;

Again, this is almost line for line from TXBook and it works...sorta. I can find pickups in range no problem, but when I compute the distance (Vector2.Distance) I always get a value that is much larger than my pickup range (with my range set to 4.0 I'll get a distance of 9.3431235).

So what's happening is the scene graph is finding pickups in range but when I compute the distance between the player and the pickup it's not in range.

All this leads me to think that SceneGraph.FindObjects finds objects that are within the specified range not object positions. What I mean, is that I think SceneGraph.FindObjects will find an object whose, say, corner may be within range but not it's position (center?).

To get around all this I cooked up the following:

if (closestPickup != null && (distance < closest))
{
   closestPickup = pickup;
   closest = distance;
}
else
{
   // This will happen on the first loop thru
   closestPickup = pickup;
   closest = distance;
}

Translated into English: if SceneGraph.FindObjects finds it it's good enough for me and I'll just compare differences to each other as opposed to the pickup range.

So I have a solution to my problem, which is nice (typing this post helped my figure it out!) but I still want to know what, exactly, is SceneGraph.FindObjects returning? In this case it doesn't really matter to me that my pickups are technically out of range as it looks and feels right in the game, but I could see it mattering at some future date. Plus I'm curious now.