Include Rayleigh damping. Use struct instead of class. Update PinnedSoftBody test

include/bounce/softbody/softbody.h

@@ -26,7 +26,8 @@ class b3World;
 
 struct b3SoftBodyMesh;
 
-class b3SoftBodyNode;
+struct b3SoftBodyNode;
+struct b3SoftBodyElement;
 
 struct b3RayCastInput;
 struct b3RayCastOutput;

include/bounce/softbody/softbody_contact_solver.h

@@ -24,10 +24,10 @@
 
 class b3StackAllocator;
 
-class b3SoftBodyNode;
+struct b3SoftBodyNode;
 class b3Body;
 
-class b3NodeBodyContact;
+struct b3NodeBodyContact;
 
 struct b3DenseVec3;
 

include/bounce/softbody/softbody_node.h

@@ -25,15 +25,11 @@
 
 class b3Shape;
 class b3SoftBody;
-class b3SoftBodyNode;
+struct b3SoftBodyNode;
 
 // A contact between a node and a body
-class b3NodeBodyContact
+struct b3NodeBodyContact
 {
-public:
-	b3NodeBodyContact() { }
-	~b3NodeBodyContact() { }
-
 	b3SoftBodyNode* n1;
 	b3Shape* s2;
 
@@ -81,7 +77,7 @@ enum b3SoftBodyNodeType
 };
 
 // A soft body node.
-class b3SoftBodyNode 
+struct b3SoftBodyNode 
 {
 public:
 	// Set the node type.
@@ -110,6 +106,12 @@ public:
 	// Get the node mass.
 	float32 GetMass() const;
 
+	// Set the node damping.
+	void SetDamping(float32 damping);
+
+	// Get the node damping.
+	float32 GetDamping() const;
+
 	// Set the node radius.
 	void SetRadius(float32 radius);
 	
@@ -151,6 +153,9 @@ private:
 	// Inverse mass
 	float32 m_invMass;
 
+	// Damping
+	float32 m_damping;
+
 	// Radius
 	float32 m_radius;
 
@@ -227,6 +232,16 @@ inline float32 b3SoftBodyNode::GetMass() const
 	return m_mass;
 }
 
+inline void b3SoftBodyNode::SetDamping(float32 damping)
+{
+	m_damping = damping;
+}
+
+inline float32 b3SoftBodyNode::GetDamping() const
+{
+	return m_damping;
+}
+
 inline void b3SoftBodyNode::SetRadius(float32 radius)
 {
 	m_radius = radius;

include/bounce/softbody/softbody_solver.h

@@ -27,10 +27,10 @@ class b3StackAllocator;
 class b3SoftBody;
 class b3SoftBodyMesh;
 
-class b3SoftBodyNode;
+struct b3SoftBodyNode;
 struct b3SoftBodyElement;
 
-class b3NodeBodyContact;
+struct b3NodeBodyContact;
 
 struct b3SoftBodySolverDef
 {