[ggt-devel] [ ggt-Bugs-3234230 ] AABox/AABox sweep intersection problem

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Bugs item #3234230, was opened at 2011-03-22 03:12
Message generated for change (Comment added) made by patrickh
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Category: GMTL
Group: HEAD
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Patrick Hartling (patrickh)
Summary: AABox/AABox sweep intersection problem

Initial Comment:
Version: GMTL 0.5.2-1 deb

The attached file demonstrates that the AABox/AABox sweep intersection test returns a false positive if any component of the relative velocity of the two boxes is zero.

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>Comment By: Patrick Hartling (patrickh)
Date: 2011-03-27 13:32

Message:
Ignore my question. I didn't realize that the bug tracker showed comments
in reverse chronological order. I now understand that the proposed change
was incorrect.

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Comment By: Patrick Hartling (patrickh)
Date: 2011-03-27 13:31

Message:
The proposed patch causes a test case in the test suite to fail.
Specifically, it breaks
gmtlTest::IntersectionTest::testIntersectAABoxSweep() (see
Test/TestSuite/TestCases/IntersectionTest.cpp). Does that mean that that
test is incorrect or that the patch is incorrect?

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Comment By: Nobody/Anonymous (nobody)
Date: 2011-03-23 03:24

Message:
Eek!  I just looked at the patch I added and it is _wrong_.  Really wrong. 
Sorry for the noise.  If I come up with a better patch, I'll post it later.

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Comment By: Nobody/Anonymous (nobody)
Date: 2011-03-22 22:57

Message:
Here's the patch that I am using to correct this problem.  Sorry about the
formatting -- I don't have a Sourceforge account, so I can't attach files.

*** Intersection.h.orig 2011-03-22 20:54:30.198177237 -0700
--- /usr/include/gmtl-0.5.2/gmtl/Intersection.h 2011-03-22
20:54:36.771836476 -0700
***************
*** 152,157 ****
--- 152,161 ----
           {
              overlap1[i] = (box1.getMin()[i] - box2.getMax()[i]) /
path[i];
           }
+          else
+          {
+             return false;
+          }
  
           if ((box2.getMax()[i] > box1.getMin()[i]) && (path[i] <
DATA_TYPE(0)))
           {
***************
*** 161,166 ****
--- 165,174 ----
           {
              overlap2[i] = (box1.getMax()[i] - box2.getMin()[i]) /
path[i];
           }
+          else
+          {
+             return false;
+          }
        }
  
        // Calculate the first time of overlap

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You can respond by visiting: 
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