add gjk/epa (host only), possibly improve convex-convex with many edge-edge tests

more preparation towards persistent/incremental contact cache

src/Bullet3OpenCL/NarrowphaseCollision/b3SupportMappings.h

@@ -0,0 +1,36 @@
+
+#ifndef B3_SUPPORT_MAPPINGS_H
+#define B3_SUPPORT_MAPPINGS_H
+
+#include "Bullet3Common/b3Transform.h"
+#include "Bullet3Common/b3AlignedObjectArray.h"
+#include "b3VectorFloat4.h"
+
+struct b3ConvexPolyhedronCL;
+struct b3GjkPairDetector;
+
+inline b3Vector3 localGetSupportVertexWithMargin(const float4& supportVec,const struct b3ConvexPolyhedronCL* hull, 
+	const b3AlignedObjectArray<b3Vector3>& verticesA, b3Scalar margin)
+{
+	b3Vector3 supVec(b3Scalar(0.),b3Scalar(0.),b3Scalar(0.));
+	b3Scalar maxDot = b3Scalar(-B3_LARGE_FLOAT);
+
+    // Here we take advantage of dot(a, b*c) = dot(a*b, c).  Note: This is true mathematically, but not numerically. 
+    if( 0 < hull->m_numVertices )
+    {
+        const b3Vector3 scaled = supportVec;
+		int index = (int) scaled.maxDot( &verticesA[hull->m_vertexOffset], hull->m_numVertices, maxDot); 
+        return verticesA[hull->m_vertexOffset+index];
+    }
+
+    return supVec;
+
+}
+
+inline b3Vector3 localGetSupportVertexWithoutMargin(const float4& supportVec,const struct b3ConvexPolyhedronCL* hull, 
+	const b3AlignedObjectArray<b3Vector3>& verticesA)
+{
+	return localGetSupportVertexWithMargin(supportVec,hull,verticesA,0.f);
+}
+
+#endif //B3_SUPPORT_MAPPINGS_H