Possible UIDraggablePanel RestrictWithinBounds bug when resetting position

[seandanger]

I have a vertically-oriented UIDraggablePanel in my scene.  After dragging the contents downward, they snap back up into position as expected.  There is a minor problem though, as the calculated position the DraggablePanel moves back toward is slightly higher than it was previously, each time.  This result is my panel has a "resting position" many pixels above its original resting position.  Ideally, it would not do this and instead go no higher than its original position (which in my case, is y == 0.0f).

Here's a small video demonstrating it, sorry for the blurriness, but you should get the idea: http://www.youtube.com/watch?v=PFQFwgxhilA

I'll look into a workaround for now, just wanted to see if anyone knew about it or if ArenMook was working on it, or if I possibly have my panel setup incorrectly.  I'll update if I find my own fix.

@Aren So far, it looks like the problem comes from SpringPanel over-shooting the panel's position when it returns.

EDIT: The opposite also happens when dragging the panel beyond its upper limits so that it snaps back down slightly too far each time.

[ArenMook]

Hmm... That's odd. Try changing SpringPanel line 56 from:

1. if (mThreshold >= (target - mTrans.localPosition).magnitude) enabled = false;

to:

1. if (mThreshold >= (target - mTrans.localPosition).magnitude)
2. {
3.         mTrans.localPosition = target;
4.         enabled = false;
5. }

[seandanger]

That's the code I already have there.  I believe I'm using v2.1.0.

I think I was wrong about SpringPanel overshooting it's target, since that localPosition = target line is there, but in UIDraggablePanel line 237, inside RestrictWithinBounds, with:

1. SpringPanel.Begin(mPanel.gameObject, mTrans.localPosition + constraint, 13f);

mTrans.localPosition.y slowly increases.  I don't see how it's doing that when the localPos is getting set to the target when SpringPanel ends.

EDIT: It must be that, initially, the target is being calculated with some extra added.  Note that if I change the RestrictWithinBounds() call at line 621 to pass true instead of false, it snaps back to the proper position each time.

[ArenMook]

Aha, the clip doesnt get adjusted properly. Try this:

1.         void Update ()
2.         {
3.                 float delta = UpdateRealTimeDelta();
4.  
5.                 if (mThreshold == 0f) mThreshold = (target - mTrans.localPosition).magnitude * 0.005f;
6.  
7.                 Vector3 before = mTrans.localPosition;
8.                 Vector3 after = NGUIMath.SpringLerp(mTrans.localPosition, target, strength, delta);
9.  
10.                 if (mThreshold >= Vector3.Magnitude(after - target))
11.                 {
12.                         after = target;
13.                         enabled = false;
14.                 }
15.                 mTrans.localPosition = after;
16.  
17.                 Vector3 offset = after - before;
18.                 Vector4 cr = mPanel.clipRange;
19.                 cr.x -= offset.x;
20.                 cr.y -= offset.y;
21.                 mPanel.clipRange = cr;
22.  
23.                 if (mDrag != null) mDrag.UpdateScrollbars(false);
24.         }

[seandanger]

Beautiful

I know it was a silly little issue, but it was coming into play a lot after running the game for awhile.  Thanks so much!