From 804d99e3922a1bb3ec7b8a32140b71186cb50e3d Mon Sep 17 00:00:00 2001
From: ejcoumans <ejcoumans@08e121b0-ae19-0410-a57b-3be3395fd4fd>
Date: Sun, 24 Sep 2006 04:21:11 +0000
Subject: [PATCH] fixed bug in PolyhedralConvexShape supportmapping, and better
 description for GJK max iteration exit

---
 Bullet/CollisionShapes/PolyhedralConvexShape.cpp | 15 ++++++++++-----
 Bullet/NarrowPhaseCollision/GjkPairDetector.cpp  |  2 +-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/Bullet/CollisionShapes/PolyhedralConvexShape.cpp b/Bullet/CollisionShapes/PolyhedralConvexShape.cpp
index bfdf75014..3aaf7c059 100644
--- a/Bullet/CollisionShapes/PolyhedralConvexShape.cpp
+++ b/Bullet/CollisionShapes/PolyhedralConvexShape.cpp
@@ -66,20 +66,25 @@ void	PolyhedralConvexShape::BatchedUnitVectorGetSupportingVertexWithoutMargin(co
 	SimdVector3 vtx;
 	SimdScalar newDot;
 
+	for (int i=0;i<numVectors;i++)
+	{
+		supportVerticesOut[i][3] = -1e30f;
+	}
+
 	for (int j=0;j<numVectors;j++)
 	{
-		SimdScalar maxDot(-1e30f);
-
+	
 		const SimdVector3& vec = vectors[j];
 
 		for (i=0;i<GetNumVertices();i++)
 		{
 			GetVertex(i,vtx);
 			newDot = vec.dot(vtx);
-			if (newDot > maxDot)
+			if (newDot > supportVerticesOut[j][3])
 			{
-				maxDot = newDot;
-				supportVerticesOut[i] = vtx;
+				//WARNING: don't swap next lines, the w component would get overwritten!
+				supportVerticesOut[j] = vtx;
+				supportVerticesOut[j][3] = newDot;
 			}
 		}
 	}
diff --git a/Bullet/NarrowPhaseCollision/GjkPairDetector.cpp b/Bullet/NarrowPhaseCollision/GjkPairDetector.cpp
index 0887ba719..b6353ff12 100644
--- a/Bullet/NarrowPhaseCollision/GjkPairDetector.cpp
+++ b/Bullet/NarrowPhaseCollision/GjkPairDetector.cpp
@@ -77,7 +77,7 @@ int curIter = 0;
 		
 		while (true)
 		{
-			//rare failure case, perhaps deferate shapes?
+			//degeneracy, this is typically due to invalid/uninitialized worldtransforms for a CollisionObject
 			if (curIter++ > gGjkMaxIter)
 			{
 				#if defined(DEBUG) || defined (_DEBUG)