add feature filtering for collision between spheres and meshes

include/bounce/collision/gjk/gjk_cache.h

@@ -46,18 +46,10 @@ b3GJKOutput b3GJK(const b3Transform& xfA, const b3GJKProxy& proxyA,
 // with the closest points.
 struct b3GJKFeaturePair
 {
-	enum Type
-	{
-		e_unknown = 0,
-		e_vertex = 1,
-		e_edge = 2,
-		e_face = 3
-	};
-
-	Type typeA; // number of vertices on proxy A
-	Type typeB; // number of vertices on proxy B
 	u32 indexA[3]; // vertices on proxy A
+	u32 countA; // number of vertices on proxy A
 	u32 indexB[3]; // vertices on proxy B
+	u32 countB; // number of vertices on proxy B
 };
 
 // Identify the vertices of the features that the closest points between two 

include/bounce/dynamics/contacts/mesh_contact.h

@@ -58,6 +58,8 @@ private:
 
 	void Collide();
 	
+	void CollideSphere();
+
 	void SynchronizeShapes();
 
 	bool MoveAABB(const b3AABB3& aabb, const b3Vec3& displacement);

include/testbed/tests/distance_test.h

@@ -54,13 +54,13 @@ public:
 		{
 			b3GJKFeaturePair featurePair = b3GetFeaturePair(m_cache);
 
-			for (u32 i = 0; i < (u32)featurePair.typeA; ++i)
+			for (u32 i = 0; i < featurePair.countA; ++i)
 			{
 				u32 index = featurePair.indexA[i];
 				g_debugDraw->DrawPoint(m_xfA * m_proxyA.GetVertex(index), b3Color(1.0f, 1.0f, 0.0f));
 			}
 
-			for (u32 i = 0; i < (u32)featurePair.typeB; ++i)
+			for (u32 i = 0; i < featurePair.countB; ++i)
 			{
 				u32 index = featurePair.indexB[i];
 				g_debugDraw->DrawPoint(m_xfB * m_proxyB.GetVertex(index), b3Color(1.0f, 1.0f, 0.0f));
@@ -133,4 +133,4 @@ public:
 	b3SimplexCache m_cache;
 };
 
-#endif
+#endif